                                FreeBSD Handbook

  The FreeBSD Documentation Project

   Revision: 0d4371e5cc

   Copyright (c) 1995-2021 The FreeBSD Documentation Project

   Copyright

   Redistribution and use in source (XML DocBook) and 'compiled' forms (XML,
   HTML, PDF, PostScript, RTF and so forth) with or without modification, are
   permitted provided that the following conditions are met:

    1. Redistributions of source code (XML DocBook) must retain the above
       copyright notice, this list of conditions and the following disclaimer
       as the first lines of this file unmodified.

    2. Redistributions in compiled form (transformed to other DTDs, converted
       to PDF, PostScript, RTF and other formats) must reproduce the above
       copyright notice, this list of conditions and the following disclaimer
       in the documentation and/or other materials provided with the
       distribution.

  Important:

   THIS DOCUMENTATION IS PROVIDED BY THE FREEBSD DOCUMENTATION PROJECT "AS
   IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
   THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FREEBSD DOCUMENTATION
   PROJECT BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   DOCUMENTATION, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

   FreeBSD is a registered trademark of the FreeBSD Foundation.

   3Com and HomeConnect are registered trademarks of 3Com Corporation.

   3ware is a registered trademark of 3ware Inc.

   ARM is a registered trademark of ARM Limited.

   Adaptec is a registered trademark of Adaptec, Inc.

   Adobe, Acrobat, Acrobat Reader, Flash and PostScript are either registered
   trademarks or trademarks of Adobe Systems Incorporated in the United
   States and/or other countries.

   Apple, AirPort, FireWire, iMac, iPhone, iPad, Mac, Macintosh, Mac OS,
   Quicktime, and TrueType are trademarks of Apple Inc., registered in the
   U.S. and other countries.

   Android is a trademark of Google Inc.

   Heidelberg, Helvetica, Palatino, and Times Roman are either registered
   trademarks or trademarks of Heidelberger Druckmaschinen AG in the U.S. and
   other countries.

   IBM, AIX, OS/2, PowerPC, PS/2, S/390, and ThinkPad are trademarks of
   International Business Machines Corporation in the United States, other
   countries, or both.

   IEEE, POSIX, and 802 are registered trademarks of Institute of Electrical
   and Electronics Engineers, Inc. in the United States.

   Intel, Celeron, Centrino, Core, EtherExpress, i386, i486, Itanium,
   Pentium, and Xeon are trademarks or registered trademarks of Intel
   Corporation or its subsidiaries in the United States and other countries.

   Intuit and Quicken are registered trademarks and/or registered service
   marks of Intuit Inc., or one of its subsidiaries, in the United States and
   other countries.

   Linux is a registered trademark of Linus Torvalds.

   LSI Logic, AcceleRAID, eXtremeRAID, MegaRAID and Mylex are trademarks or
   registered trademarks of LSI Logic Corp.

   Microsoft, IntelliMouse, MS-DOS, Outlook, Windows, Windows Media and
   Windows NT are either registered trademarks or trademarks of Microsoft
   Corporation in the United States and/or other countries.

   Motif, OSF/1, and UNIX are registered trademarks and IT DialTone and The
   Open Group are trademarks of The Open Group in the United States and other
   countries.

   Oracle is a registered trademark of Oracle Corporation.

   RealNetworks, RealPlayer, and RealAudio are the registered trademarks of
   RealNetworks, Inc.

   Red Hat, RPM, are trademarks or registered trademarks of Red Hat, Inc. in
   the United States and other countries.

   Sun, Sun Microsystems, Java, Java Virtual Machine, JDK, JRE, JSP, JVM,
   Netra, OpenJDK, Solaris, StarOffice, SunOS and VirtualBox are trademarks
   or registered trademarks of Sun Microsystems, Inc. in the United States
   and other countries.

   MATLAB is a registered trademark of The MathWorks, Inc.

   SpeedTouch is a trademark of Thomson.

   VMware is a trademark of VMware, Inc.

   Mathematica is a registered trademark of Wolfram Research, Inc.

   XFree86 is a trademark of The XFree86 Project, Inc.

   Ogg Vorbis and Xiph.Org are trademarks of Xiph.Org.

   Many of the designations used by manufacturers and sellers to distinguish
   their products are claimed as trademarks. Where those designations appear
   in this document, and the FreeBSD Project was aware of the trademark
   claim, the designations have been followed by the "(TM)" or the "(R)"
   symbol.

   Last modified on 2021-01-18 18:33:37 +0100 by Fernando Apesteguia.
   Abstract

   Welcome to FreeBSD! This handbook covers the installation and day to day
   use of FreeBSD 12.2-RELEASE, FreeBSD 12.1-RELEASE, and FreeBSD
   11.4-RELEASE. This book is the result of ongoing work by many individuals.
   Some sections might be outdated. Those interested in helping to update and
   expand this document should send email to the FreeBSD documentation
   project mailing list.

   The latest version of this book is available from the FreeBSD web site.
   Previous versions can be obtained from https://docs.FreeBSD.org/doc/. The
   book can be downloaded in a variety of formats and compression options
   from the FreeBSD FTP server or one of the numerous mirror sites. Printed
   copies can be purchased at the FreeBSD Mall. Searches can be performed on
   the handbook and other documents on the search page.

   [ Split HTML / Single HTML ]

     ----------------------------------------------------------------------

   Table of Contents

   Preface

   I. Getting Started

                1. Introduction

                             1.1. Synopsis

                             1.2. Welcome to FreeBSD!

                             1.3. About the FreeBSD Project

                2. Installing FreeBSD

                             2.1. Synopsis

                             2.2. Minimum Hardware Requirements

                             2.3. Pre-Installation Tasks

                             2.4. Starting the Installation

                             2.5. Using bsdinstall

                             2.6. Allocating Disk Space

                             2.7. Fetching Distribution Files

                             2.8. Accounts, Time Zone, Services and Hardening

                             2.9. Network Interfaces

                             2.10. Troubleshooting

                             2.11. Using the Live CD

                3. FreeBSD Basics

                             3.1. Synopsis

                             3.2. Virtual Consoles and Terminals

                             3.3. Users and Basic Account Management

                             3.4. Permissions

                             3.5. Directory Structure

                             3.6. Disk Organization

                             3.7. Mounting and Unmounting File Systems

                             3.8. Processes and Daemons

                             3.9. Shells

                             3.10. Text Editors

                             3.11. Devices and Device Nodes

                             3.12. Manual Pages

                4. Installing Applications: Packages and Ports

                             4.1. Synopsis

                             4.2. Overview of Software Installation

                             4.3. Finding Software

                             4.4. Using pkg for Binary Package Management

                             4.5. Using the Ports Collection

                             4.6. Building Packages with Poudriere

                             4.7. Post-Installation Considerations

                             4.8. Dealing with Broken Ports

                5. The X Window System

                             5.1. Synopsis

                             5.2. Terminology

                             5.3. Installing Xorg

                             5.4. Xorg Configuration

                             5.5. Using Fonts in Xorg

                             5.6. The X Display Manager

                             5.7. Desktop Environments

                             5.8. Installing Compiz Fusion

                             5.9. Troubleshooting

   II. Common Tasks

                6. Desktop Applications

                             6.1. Synopsis

                             6.2. Browsers

                             6.3. Productivity

                             6.4. Document Viewers

                             6.5. Finance

                7. Multimedia

                             7.1. Synopsis

                             7.2. Setting Up the Sound Card

                             7.3. MP3 Audio

                             7.4. Video Playback

                             7.5. TV Cards

                             7.6. MythTV

                             7.7. Image Scanners

                8. Configuring the FreeBSD Kernel

                             8.1. Synopsis

                             8.2. Why Build a Custom Kernel?

                             8.3. Finding the System Hardware

                             8.4. The Configuration File

                             8.5. Building and Installing a Custom Kernel

                             8.6. If Something Goes Wrong

                9. Printing

                             9.1. Quick Start

                             9.2. Printer Connections

                             9.3. Common Page Description Languages

                             9.4. Direct Printing

                             9.5. LPD (Line Printer Daemon)

                             9.6. Other Printing Systems

                10. Linux(R) Binary Compatibility

                             10.1. Synopsis

                             10.2. Configuring Linux(R) Binary Compatibility

                             10.3. Advanced Topics

                11. WINE

                             11.1. Synopsis

                             11.2. WINE Overview & Concepts

                             11.3. Installing WINE on FreeBSD

                             11.4. Running a First WINE Program on FreeBSD

                             11.5. Configuring WINE Installation

                             11.6. WINE Management GUIs

                             11.7. WINE in Multi-User FreeBSD Installations

                             11.8. WINE on FreeBSD FAQ

   III. System Administration

                12. Configuration and Tuning

                             12.1. Synopsis

                             12.2. Starting Services

                             12.3. Configuring cron(8)

                             12.4. Managing Services in FreeBSD

                             12.5. Setting Up Network Interface Cards

                             12.6. Virtual Hosts

                             12.7. Configuring System Logging

                             12.8. Configuration Files

                             12.9. Tuning with sysctl(8)

                             12.10. Tuning Disks

                             12.11. Tuning Kernel Limits

                             12.12. Adding Swap Space

                             12.13. Power and Resource Management

                13. The FreeBSD Booting Process

                             13.1. Synopsis

                             13.2. FreeBSD Boot Process

                             13.3. Configuring Boot Time Splash Screens

                             13.4. Device Hints

                             13.5. Shutdown Sequence

                14. Security

                             14.1. Synopsis

                             14.2. Introduction

                             14.3. One-time Passwords

                             14.4. TCP Wrapper

                             14.5. Kerberos

                             14.6. OpenSSL

                             14.7. VPN over IPsec

                             14.8. OpenSSH

                             14.9. Access Control Lists

                             14.10. Monitoring Third Party Security Issues

                             14.11. FreeBSD Security Advisories

                             14.12. Process Accounting

                             14.13. Resource Limits

                             14.14. Shared Administration with Sudo

                15. Jails

                             15.1. Synopsis

                             15.2. Terms Related to Jails

                             15.3. Creating and Controlling Jails

                             15.4. Fine Tuning and Administration

                             15.5. Updating Multiple Jails

                             15.6. Managing Jails with ezjail

                16. Mandatory Access Control

                             16.1. Synopsis

                             16.2. Key Terms

                             16.3. Understanding MAC Labels

                             16.4. Planning the Security Configuration

                             16.5. Available MAC Policies

                             16.6. User Lock Down

                             16.7. Nagios in a MAC Jail

                             16.8. Troubleshooting the MAC Framework

                17. Security Event Auditing

                             17.1. Synopsis

                             17.2. Key Terms

                             17.3. Audit Configuration

                             17.4. Working with Audit Trails

                18. Storage

                             18.1. Synopsis

                             18.2. Adding Disks

                             18.3. Resizing and Growing Disks

                             18.4. USB Storage Devices

                             18.5. Creating and Using CD Media

                             18.6. Creating and Using DVD Media

                             18.7. Creating and Using Floppy Disks

                             18.8. Backup Basics

                             18.9. Memory Disks

                             18.10. File System Snapshots

                             18.11. Disk Quotas

                             18.12. Encrypting Disk Partitions

                             18.13. Encrypting Swap

                             18.14. Highly Available Storage (HAST)

                19. GEOM: Modular Disk Transformation Framework

                             19.1. Synopsis

                             19.2. RAID0 - Striping

                             19.3. RAID1 - Mirroring

                             19.4. RAID3 - Byte-level Striping with Dedicated
                             Parity

                             19.5. Software RAID Devices

                             19.6. GEOM Gate Network

                             19.7. Labeling Disk Devices

                             19.8. UFS Journaling Through GEOM

                20. The Z File System (ZFS)

                             20.1. What Makes ZFS Different

                             20.2. Quick Start Guide

                             20.3. zpool Administration

                             20.4. zfs Administration

                             20.5. Delegated Administration

                             20.6. Advanced Topics

                             20.7. Additional Resources

                             20.8. ZFS Features and Terminology

                21. Other File Systems

                             21.1. Synopsis

                             21.2. Linux(R) File Systems

                22. Virtualization

                             22.1. Synopsis

                             22.2. FreeBSD as a Guest on Parallels for
                             Mac OS(R) X

                             22.3. FreeBSD as a Guest on Virtual PC for
                             Windows(R)

                             22.4. FreeBSD as a Guest on VMware Fusion for
                             Mac OS(R)

                             22.5. FreeBSD as a Guest on VirtualBox(TM)

                             22.6. FreeBSD as a Host with VirtualBox(TM)

                             22.7. FreeBSD as a Host with bhyve

                             22.8. FreeBSD as a Xen(TM)-Host

                23. Localization - i18n/L10n Usage and Setup

                             23.1. Synopsis

                             23.2. Using Localization

                             23.3. Finding i18n Applications

                             23.4. Locale Configuration for Specific
                             Languages

                24. Updating and Upgrading FreeBSD

                             24.1. Synopsis

                             24.2. FreeBSD Update

                             24.3. Updating the Documentation Set

                             24.4. Tracking a Development Branch

                             24.5. Updating FreeBSD from Source

                             24.6. Tracking for Multiple Machines

                25. DTrace

                             25.1. Synopsis

                             25.2. Implementation Differences

                             25.3. Enabling DTrace Support

                             25.4. Using DTrace

                26. USB Device Mode / USB OTG

                             26.1. Synopsis

                             26.2. USB Virtual Serial Ports

                             26.3. USB Device Mode Network Interfaces

                             26.4. USB Virtual Storage Device

   IV. Network Communication

                27. Serial Communications

                             27.1. Synopsis

                             27.2. Serial Terminology and Hardware

                             27.3. Terminals

                             27.4. Dial-in Service

                             27.5. Dial-out Service

                             27.6. Setting Up the Serial Console

                28. PPP

                             28.1. Synopsis

                             28.2. Configuring PPP

                             28.3. Troubleshooting PPP Connections

                             28.4. Using PPP over Ethernet (PPPoE)

                             28.5. Using PPP over ATM (PPPoA)

                29. Electronic Mail

                             29.1. Synopsis

                             29.2. Mail Components

                             29.3. Sendmail Configuration Files

                             29.4. Changing the Mail Transfer Agent

                             29.5. Troubleshooting

                             29.6. Advanced Topics

                             29.7. Setting Up to Send Only

                             29.8. Using Mail with a Dialup Connection

                             29.9. SMTP Authentication

                             29.10. Mail User Agents

                             29.11. Using fetchmail

                             29.12. Using procmail

                30. Network Servers

                             30.1. Synopsis

                             30.2. The inetd Super-Server

                             30.3. Network File System (NFS)

                             30.4. Network Information System (NIS)

                             30.5. Lightweight Directory Access Protocol
                             (LDAP)

                             30.6. Dynamic Host Configuration Protocol (DHCP)

                             30.7. Domain Name System (DNS)

                             30.8. Apache HTTP Server

                             30.9. File Transfer Protocol (FTP)

                             30.10. File and Print Services for
                             Microsoft(R) Windows(R) Clients (Samba)

                             30.11. Clock Synchronization with NTP

                             30.12. iSCSI Initiator and Target Configuration

                31. Firewalls

                             31.1. Synopsis

                             31.2. Firewall Concepts

                             31.3. PF

                             31.4. IPFW

                             31.5. IPFILTER (IPF)

                             31.6. Blacklistd

                32. Advanced Networking

                             32.1. Synopsis

                             32.2. Gateways and Routes

                             32.3. Wireless Networking

                             32.4. USB Tethering

                             32.5. Bluetooth

                             32.6. Bridging

                             32.7. Link Aggregation and Failover

                             32.8. Diskless Operation with PXE

                             32.9. IPv6

                             32.10. Common Address Redundancy Protocol (CARP)

                             32.11. VLANs

   V. Appendices

                A. Obtaining FreeBSD

                             A.1. CD and DVD Sets

                             A.2. FTP Sites

                             A.3. Using Subversion

                             A.4. Using rsync

                B. Bibliography

                             B.1. Books Specific to FreeBSD

                             B.2. Users' Guides

                             B.3. Administrators' Guides

                             B.4. Programmers' Guides

                             B.5. Operating System Internals

                             B.6. Security Reference

                             B.7. Hardware Reference

                             B.8. UNIX(R) History

                             B.9. Periodicals, Journals, and Magazines

                C. Resources on the Internet

                             C.1. Websites

                             C.2. Mailing Lists

                             C.3. Usenet Newsgroups

                             C.4. Official Mirrors

                D. OpenPGP Keys

                             D.1. Officers

   FreeBSD Glossary

   Index

   List of Figures

   2.1. FreeBSD Boot Loader Menu

   2.2. FreeBSD Boot Options Menu

   2.3. Welcome Menu

   2.4. Keymap Loading

   2.5. Keymap Selection Menu

   2.6. Keymap Testing Menu

   2.7. Setting the Hostname

   2.8. Selecting Components to Install

   2.9. Installing from the Network

   2.10. Partitioning Choices

   2.11. Selecting from Multiple Disks

   2.12. Selecting Entire Disk or Partition

   2.13. Confirmation

   2.14. Select Partition Scheme

   2.15. Review Created Partitions

   2.16. Final Confirmation

   2.17. Manually Create Partitions

   2.18. Manually Create Partitions

   2.19. Manually Create Partitions

   2.20. ZFS Partitioning Menu

   2.21. ZFS Pool Type

   2.22. Disk Selection

   2.23. Invalid Selection

   2.24. Rescan Devices

   2.25. Analyzing a Disk

   2.26. Pool Name

   2.27. Swap Amount

   2.28. Last Chance

   2.29. Disk Encryption Password

   2.30. Initializing Encryption

   2.31. Fetching Distribution Files

   2.32. Verifying Distribution Files

   2.33. Extracting Distribution Files

   2.34. Setting the root Password

   2.35. Select a Region

   2.36. Select a Country

   2.37. Select a Time Zone

   2.38. Confirm Time Zone

   2.39. Select Date

   2.40. Select Time

   2.41. Selecting Additional Services to Enable

   2.42. Selecting Hardening Security Options

   2.43. Add User Accounts

   2.44. Enter User Information

   2.45. Exit User and Group Management

   2.46. Final Configuration

   2.47. Manual Configuration

   2.48. Complete the Installation

   2.49. Choose a Network Interface

   2.50. Scanning for Wireless Access Points

   2.51. Choosing a Wireless Network

   2.52. WPA2 Setup

   2.53. Choose IPv4 Networking

   2.54. Choose IPv4 DHCP Configuration

   2.55. IPv4 Static Configuration

   2.56. Choose IPv6 Networking

   2.57. Choose IPv6 SLAAC Configuration

   2.58. IPv6 Static Configuration

   2.59. DNS Configuration

   2.60. Choosing a Mirror

   32.1. PXE Booting Process with NFS Root Mount

   List of Tables

   2.1. Partitioning Schemes

   3.1. Utilities for Managing User Accounts

   3.2. UNIX(R) Permissions

   3.3. Disk Device Names

   3.4. Common Environment Variables

   5.1. XDM Configuration Files

   7.1. Common Error Messages

   9.1. Output PDLs

   13.1. Loader Built-In Commands

   13.2. Kernel Interaction During Boot

   14.1. Login Class Resource Limits

   17.1. Default Audit Event Classes

   17.2. Prefixes for Audit Event Classes

   23.1. Common Language and Country Codes

   23.2. Defined Terminal Types for Character Sets

   23.3. Available Console from Ports Collection

   23.4. Available Input Methods

   24.1. FreeBSD Versions and Repository Paths

   27.1. RS-232C Signal Names

   27.2. DB-25 to DB-25 Null-Modem Cable

   27.3. DB-9 to DB-9 Null-Modem Cable

   27.4. DB-9 to DB-25 Null-Modem Cable

   30.1. NIS Terminology

   30.2. Additional Users

   30.3. Additional Systems

   30.4. DNS Terminology

   31.1. Useful pfctl Options

   32.1. Commonly Seen Routing Table Flags

   32.2. Station Capability Codes

   32.3. Reserved IPv6 Addresses

   List of Examples

   2.1. Creating Traditional Split File System Partitions

   3.1. Install a Program As the Superuser

   3.2. Adding a User on FreeBSD

   3.3. rmuser Interactive Account Removal

   3.4. Using chpass as Superuser

   3.5. Using chpass as Regular User

   3.6. Changing Your Password

   3.7. Changing Another User's Password as the Superuser

   3.8. Adding a Group Using pw(8)

   3.9. Adding User Accounts to a New Group Using pw(8)

   3.10. Adding a New Member to a Group Using pw(8)

   3.11. Using id(1) to Determine Group Membership

   3.12. Sample Disk, Slice, and Partition Names

   3.13. Conceptual Model of a Disk

   5.1. Select Intel(R) Video Driver in a File

   5.2. Select Radeon Video Driver in a File

   5.3. Select VESA Video Driver in a File

   5.4. Select scfb Video Driver in a File

   5.5. Set Screen Resolution in a File

   5.6. Manually Setting Monitor Frequencies

   5.7. Setting a Keyboard Layout

   5.8. Setting Multiple Keyboard Layouts

   5.9. Enabling Keyboard Exit from X

   5.10. Setting the Number of Mouse Buttons

   12.1. Sample Log Server Configuration

   12.2. Creating a Swap File

   13.1. boot0 Screenshot

   13.2. boot2 Screenshot

   13.3. Configuring an Insecure Console in /etc/ttys

   14.1. Create a Secure Tunnel for SMTP

   14.2. Secure Access of a POP3 Server

   14.3. Bypassing a Firewall

   15.1. mergemaster(8) on Untrusted Jail

   15.2. mergemaster(8) on Trusted Jail

   15.3. Running BIND in a Jail

   18.1. Using dump over ssh

   18.2. Using dump over ssh with RSH Set

   18.3. Backing Up the Current Directory with tar

   18.4. Restoring Up the Current Directory with tar

   18.5. Using ls and cpio to Make a Recursive Backup of the Current
   Directory

   18.6. Backing Up the Current Directory with pax

   19.1. Labeling Partitions on the Boot Disk

   24.1. Increasing the Number of Build Jobs

   27.1. Configuring Terminal Entries

   30.1. Reloading the inetd Configuration File

   30.2. Mounting an Export with autofs(5)

   30.3. Sample /etc/ntp.conf

   32.1. LACP Aggregation with a Cisco(R) Switch

   32.2. Failover Mode

   32.3. Failover Mode Between Ethernet and Wireless Interfaces

                                    Preface

Intended Audience

   The FreeBSD newcomer will find that the first section of this book guides
   the user through the FreeBSD installation process and gently introduces
   the concepts and conventions that underpin UNIX(R). Working through this
   section requires little more than the desire to explore, and the ability
   to take on board new concepts as they are introduced.

   Once you have traveled this far, the second, far larger, section of the
   Handbook is a comprehensive reference to all manner of topics of interest
   to FreeBSD system administrators. Some of these chapters may recommend
   that you do some prior reading, and this is noted in the synopsis at the
   beginning of each chapter.

   For a list of additional sources of information, please see Appendix B,
   Bibliography.

Changes from the Third Edition

   The current online version of the Handbook represents the cumulative
   effort of many hundreds of contributors over the past 10 years. The
   following are some of the significant changes since the two volume third
   edition was published in 2004:

     * Chapter 11, WINE has been added with information about how to run
       Windows(R) applications on FreeBSD.

     * Chapter 25, DTrace has been added with information about the powerful
       DTrace performance analysis tool.

     * Chapter 21, Other File Systems has been added with information about
       non-native file systems in FreeBSD, such as ZFS from Sun(TM).

     * Chapter 17, Security Event Auditing has been added to cover the new
       auditing capabilities in FreeBSD and explain its use.

     * Chapter 22, Virtualization has been added with information about
       installing FreeBSD on virtualization software.

     * Chapter 2, Installing FreeBSD has been added to cover installation of
       FreeBSD using the new installation utility, bsdinstall.

Changes from the Second Edition (2004)

   The third edition was the culmination of over two years of work by the
   dedicated members of the FreeBSD Documentation Project. The printed
   edition grew to such a size that it was necessary to publish as two
   separate volumes. The following are the major changes in this new edition:

     * Chapter 12, Configuration and Tuning has been expanded with new
       information about the ACPI power and resource management, the cron
       system utility, and more kernel tuning options.

     * Chapter 14, Security has been expanded with new information about
       virtual private networks (VPNs), file system access control lists
       (ACLs), and security advisories.

     * Chapter 16, Mandatory Access Control is a new chapter with this
       edition. It explains what MAC is and how this mechanism can be used to
       secure a FreeBSD system.

     * Chapter 18, Storage has been expanded with new information about USB
       storage devices, file system snapshots, file system quotas, file and
       network backed filesystems, and encrypted disk partitions.

     * A troubleshooting section has been added to Chapter 28, PPP.

     * Chapter 29, Electronic Mail has been expanded with new information
       about using alternative transport agents, SMTP authentication, UUCP,
       fetchmail, procmail, and other advanced topics.

     * Chapter 30, Network Servers is all new with this edition. This chapter
       includes information about setting up the Apache HTTP Server, ftpd,
       and setting up a server for Microsoft(R) Windows(R) clients with
       Samba. Some sections from Chapter 32, Advanced Networking were moved
       here to improve the presentation.

     * Chapter 32, Advanced Networking has been expanded with new information
       about using Bluetooth(R) devices with FreeBSD, setting up wireless
       networks, and Asynchronous Transfer Mode (ATM) networking.

     * A glossary has been added to provide a central location for the
       definitions of technical terms used throughout the book.

     * A number of aesthetic improvements have been made to the tables and
       figures throughout the book.

Changes from the First Edition (2001)

   The second edition was the culmination of over two years of work by the
   dedicated members of the FreeBSD Documentation Project. The following were
   the major changes in this edition:

     * A complete Index has been added.

     * All ASCII figures have been replaced by graphical diagrams.

     * A standard synopsis has been added to each chapter to give a quick
       summary of what information the chapter contains, and what the reader
       is expected to know.

     * The content has been logically reorganized into three parts: "Getting
       Started", "System Administration", and "Appendices".

     * Chapter 3, FreeBSD Basics has been expanded to contain additional
       information about processes, daemons, and signals.

     * Chapter 4, Installing Applications: Packages and Ports has been
       expanded to contain additional information about binary package
       management.

     * Chapter 5, The X Window System has been completely rewritten with an
       emphasis on using modern desktop technologies such as KDE and GNOME on
       XFree86(TM) 4.X.

     * Chapter 13, The FreeBSD Booting Process has been expanded.

     * Chapter 18, Storage has been written from what used to be two separate
       chapters on "Disks" and "Backups". We feel that the topics are easier
       to comprehend when presented as a single chapter. A section on RAID
       (both hardware and software) has also been added.

     * Chapter 27, Serial Communications has been completely reorganized and
       updated for FreeBSD 4.X/5.X.

     * Chapter 28, PPP has been substantially updated.

     * Many new sections have been added to Chapter 32, Advanced Networking.

     * Chapter 29, Electronic Mail has been expanded to include more
       information about configuring sendmail.

     * Chapter 10, Linux(R) Binary Compatibility has been expanded to include
       information about installing Oracle(R) and SAP(R) R/3(R).

     * The following new topics are covered in this second edition:

          * Chapter 12, Configuration and Tuning.

          * Chapter 7, Multimedia.

Organization of This Book

   This book is split into five logically distinct sections. The first
   section, Getting Started, covers the installation and basic usage of
   FreeBSD. It is expected that the reader will follow these chapters in
   sequence, possibly skipping chapters covering familiar topics. The second
   section, Common Tasks, covers some frequently used features of FreeBSD.
   This section, and all subsequent sections, can be read out of order. Each
   chapter begins with a succinct synopsis that describes what the chapter
   covers and what the reader is expected to already know. This is meant to
   allow the casual reader to skip around to find chapters of interest. The
   third section, System Administration, covers administration topics. The
   fourth section, Network Communication, covers networking and server
   topics. The fifth section contains appendices of reference information.

   Chapter 1, Introduction

           Introduces FreeBSD to a new user. It describes the history of the
           FreeBSD Project, its goals and development model.

   Chapter 2, Installing FreeBSD

           Walks a user through the entire installation process of
           FreeBSD 9.x and later using bsdinstall.

   Chapter 3, FreeBSD Basics

           Covers the basic commands and functionality of the FreeBSD
           operating system. If you are familiar with Linux(R) or another
           flavor of UNIX(R) then you can probably skip this chapter.

   Chapter 4, Installing Applications: Packages and Ports

           Covers the installation of third-party software with both
           FreeBSD's innovative "Ports Collection" and standard binary
           packages.

   Chapter 5, The X Window System

           Describes the X Window System in general and using X11 on FreeBSD
           in particular. Also describes common desktop environments such as
           KDE and GNOME.

   Chapter 6, Desktop Applications

           Lists some common desktop applications, such as web browsers and
           productivity suites, and describes how to install them on FreeBSD.

   Chapter 7, Multimedia

           Shows how to set up sound and video playback support for your
           system. Also describes some sample audio and video applications.

   Chapter 8, Configuring the FreeBSD Kernel

           Explains why you might need to configure a new kernel and provides
           detailed instructions for configuring, building, and installing a
           custom kernel.

   Chapter 9, Printing

           Describes managing printers on FreeBSD, including information
           about banner pages, printer accounting, and initial setup.

   Chapter 10, Linux(R) Binary Compatibility

           Describes the Linux(R) compatibility features of FreeBSD. Also
           provides detailed installation instructions for many popular
           Linux(R) applications such as Oracle(R) and Mathematica(R).

   Chapter 12, Configuration and Tuning

           Describes the parameters available for system administrators to
           tune a FreeBSD system for optimum performance. Also describes the
           various configuration files used in FreeBSD and where to find
           them.

   Chapter 13, The FreeBSD Booting Process

           Describes the FreeBSD boot process and explains how to control
           this process with configuration options.

   Chapter 14, Security

           Describes many different tools available to help keep your FreeBSD
           system secure, including Kerberos, IPsec and OpenSSH.

   Chapter 15, Jails

           Describes the jails framework, and the improvements of jails over
           the traditional chroot support of FreeBSD.

   Chapter 16, Mandatory Access Control

           Explains what Mandatory Access Control (MAC) is and how this
           mechanism can be used to secure a FreeBSD system.

   Chapter 17, Security Event Auditing

           Describes what FreeBSD Event Auditing is, how it can be installed,
           configured, and how audit trails can be inspected or monitored.

   Chapter 18, Storage

           Describes how to manage storage media and filesystems with
           FreeBSD. This includes physical disks, RAID arrays, optical and
           tape media, memory-backed disks, and network filesystems.

   Chapter 19, GEOM: Modular Disk Transformation Framework

           Describes what the GEOM framework in FreeBSD is and how to
           configure various supported RAID levels.

   Chapter 21, Other File Systems

           Examines support of non-native file systems in FreeBSD, like the Z
           File System from Sun(TM).

   Chapter 22, Virtualization

           Describes what virtualization systems offer, and how they can be
           used with FreeBSD.

   Chapter 23, Localization - i18n/L10n Usage and Setup

           Describes how to use FreeBSD in languages other than English.
           Covers both system and application level localization.

   Chapter 24, Updating and Upgrading FreeBSD

           Explains the differences between FreeBSD-STABLE, FreeBSD-CURRENT,
           and FreeBSD releases. Describes which users would benefit from
           tracking a development system and outlines that process. Covers
           the methods users may take to update their system to the latest
           security release.

   Chapter 25, DTrace

           Describes how to configure and use the DTrace tool from Sun(TM) in
           FreeBSD. Dynamic tracing can help locate performance issues, by
           performing real time system analysis.

   Chapter 27, Serial Communications

           Explains how to connect terminals and modems to your FreeBSD
           system for both dial in and dial out connections.

   Chapter 28, PPP

           Describes how to use PPP to connect to remote systems with
           FreeBSD.

   Chapter 29, Electronic Mail

           Explains the different components of an email server and dives
           into simple configuration topics for the most popular mail server
           software: sendmail.

   Chapter 30, Network Servers

           Provides detailed instructions and example configuration files to
           set up your FreeBSD machine as a network filesystem server, domain
           name server, network information system server, or time
           synchronization server.

   Chapter 31, Firewalls

           Explains the philosophy behind software-based firewalls and
           provides detailed information about the configuration of the
           different firewalls available for FreeBSD.

   Chapter 32, Advanced Networking

           Describes many networking topics, including sharing an Internet
           connection with other computers on your LAN, advanced routing
           topics, wireless networking, Bluetooth(R), ATM, IPv6, and much
           more.

   Appendix A, Obtaining FreeBSD

           Lists different sources for obtaining FreeBSD media on CDROM or
           DVD as well as different sites on the Internet that allow you to
           download and install FreeBSD.

   Appendix B, Bibliography

           This book touches on many different subjects that may leave you
           hungry for a more detailed explanation. The bibliography lists
           many excellent books that are referenced in the text.

   Appendix C, Resources on the Internet

           Describes the many forums available for FreeBSD users to post
           questions and engage in technical conversations about FreeBSD.

   Appendix D, OpenPGP Keys

           Lists the PGP fingerprints of several FreeBSD Developers.

Conventions used in this book

   To provide a consistent and easy to read text, several conventions are
   followed throughout the book.

  Typographic Conventions

   Italic

           An italic font is used for filenames, URLs, emphasized text, and
           the first usage of technical terms.

   Monospace

           A monospaced font is used for error messages, commands,
           environment variables, names of ports, hostnames, user names,
           group names, device names, variables, and code fragments.

   Bold

           A bold font is used for applications, commands, and keys.

  User Input

   Keys are shown in bold to stand out from other text. Key combinations that
   are meant to be typed simultaneously are shown with `+' between the keys,
   such as:

   Ctrl+Alt+Del

   Meaning the user should type the Ctrl, Alt, and Del keys at the same time.

   Keys that are meant to be typed in sequence will be separated with commas,
   for example:

   Ctrl+X, Ctrl+S

   Would mean that the user is expected to type the Ctrl and X keys
   simultaneously and then to type the Ctrl and S keys simultaneously.

  Examples

   Examples starting with C:\> indicate a MS-DOS(R) command. Unless otherwise
   noted, these commands may be executed from a "Command Prompt" window in a
   modern Microsoft(R) Windows(R) environment.

 E:\> tools\fdimage floppies\kern.flp A:

   Examples starting with # indicate a command that must be invoked as the
   superuser in FreeBSD. You can login as root to type the command, or login
   as your normal account and use su(1) to gain superuser privileges.

 # dd if=kern.flp of=/dev/fd0

   Examples starting with % indicate a command that should be invoked from a
   normal user account. Unless otherwise noted, C-shell syntax is used for
   setting environment variables and other shell commands.

 % top

Acknowledgments

   The book you are holding represents the efforts of many hundreds of people
   around the world. Whether they sent in fixes for typos, or submitted
   complete chapters, all the contributions have been useful.

   Several companies have supported the development of this document by
   paying authors to work on it full-time, paying for publication, etc. In
   particular, BSDi (subsequently acquired by Wind River Systems) paid
   members of the FreeBSD Documentation Project to work on improving this
   book full time leading up to the publication of the first printed edition
   in March 2000 (ISBN 1-57176-241-8). Wind River Systems then paid several
   additional authors to make a number of improvements to the print-output
   infrastructure and to add additional chapters to the text. This work
   culminated in the publication of the second printed edition in November
   2001 (ISBN 1-57176-303-1). In 2003-2004, FreeBSD Mall, Inc, paid several
   contributors to improve the Handbook in preparation for the third printed
   edition.

                            Part I. Getting Started

   This part of the handbook is for users and administrators who are new to
   FreeBSD. These chapters:

     * Introduce FreeBSD.

     * Guide readers through the installation process.

     * Teach UNIX(R) basics and fundamentals.

     * Show how to install the wealth of third party applications available
       for FreeBSD.

     * Introduce X, the UNIX(R) windowing system, and detail how to configure
       a desktop environment that makes users more productive.

   The number of forward references in the text have been kept to a minimum
   so that this section can be read from front to back with minimal page
   flipping.

   Table of Contents

   1. Introduction

                1.1. Synopsis

                1.2. Welcome to FreeBSD!

                1.3. About the FreeBSD Project

   2. Installing FreeBSD

                2.1. Synopsis

                2.2. Minimum Hardware Requirements

                2.3. Pre-Installation Tasks

                2.4. Starting the Installation

                2.5. Using bsdinstall

                2.6. Allocating Disk Space

                2.7. Fetching Distribution Files

                2.8. Accounts, Time Zone, Services and Hardening

                2.9. Network Interfaces

                2.10. Troubleshooting

                2.11. Using the Live CD

   3. FreeBSD Basics

                3.1. Synopsis

                3.2. Virtual Consoles and Terminals

                3.3. Users and Basic Account Management

                3.4. Permissions

                3.5. Directory Structure

                3.6. Disk Organization

                3.7. Mounting and Unmounting File Systems

                3.8. Processes and Daemons

                3.9. Shells

                3.10. Text Editors

                3.11. Devices and Device Nodes

                3.12. Manual Pages

   4. Installing Applications: Packages and Ports

                4.1. Synopsis

                4.2. Overview of Software Installation

                4.3. Finding Software

                4.4. Using pkg for Binary Package Management

                4.5. Using the Ports Collection

                4.6. Building Packages with Poudriere

                4.7. Post-Installation Considerations

                4.8. Dealing with Broken Ports

   5. The X Window System

                5.1. Synopsis

                5.2. Terminology

                5.3. Installing Xorg

                5.4. Xorg Configuration

                5.5. Using Fonts in Xorg

                5.6. The X Display Manager

                5.7. Desktop Environments

                5.8. Installing Compiz Fusion

                5.9. Troubleshooting

Chapter 1. Introduction

   Restructured, reorganized, and parts rewritten by Jim Mock.
   Table of Contents

   1.1. Synopsis

   1.2. Welcome to FreeBSD!

   1.3. About the FreeBSD Project

1.1. Synopsis

   Thank you for your interest in FreeBSD! The following chapter covers
   various aspects of the FreeBSD Project, such as its history, goals,
   development model, and so on.

   After reading this chapter you will know:

     * How FreeBSD relates to other computer operating systems.

     * The history of the FreeBSD Project.

     * The goals of the FreeBSD Project.

     * The basics of the FreeBSD open-source development model.

     * And of course: where the name "FreeBSD" comes from.

1.2. Welcome to FreeBSD!

   FreeBSD is an Open Source, standards-compliant Unix-like operating system
   for x86 (both 32 and 64 bit), ARM(R), AArch64, RISC-V(R), MIPS(R),
   POWER(R), PowerPC(R), and Sun UltraSPARC(R) computers. It provides all the
   features that are nowadays taken for granted, such as preemptive
   multitasking, memory protection, virtual memory, multi-user facilities,
   SMP support, all the Open Source development tools for different languages
   and frameworks, and desktop features centered around X Window System, KDE,
   or GNOME. Its particular strengths are:

     * Liberal Open Source license, which grants you rights to freely modify
       and extend its source code and incorporate it in both Open Source
       projects and closed products without imposing restrictions typical to
       copyleft licenses, as well as avoiding potential license
       incompatibility problems.

     * Strong TCP/IP networking - FreeBSD implements industry standard
       protocols with ever increasing performance and scalability. This makes
       it a good match in both server, and routing/firewalling roles - and
       indeed many companies and vendors use it precisely for that purpose.

     * Fully integrated OpenZFS support, including root-on-ZFS, ZFS Boot
       Environments, fault management, administrative delegation, support for
       jails, FreeBSD specific documentation, and system installer support.

     * Extensive security features, from the Mandatory Access Control
       framework to Capsicum capability and sandbox mechanisms.

     * Over 30 thousand prebuilt packages for all supported architectures,
       and the Ports Collection which makes it easy to build your own,
       customized ones.

     * Documentation - in addition to Handbook and books from different
       authors that cover topics ranging from system administration to kernel
       internals, there are also the man(1) pages, not only for userspace
       daemons, utilities, and configuration files, but also for kernel
       driver APIs (section 9) and individual drivers (section 4).

     * Simple and consistent repository structure and build system - FreeBSD
       uses a single repository for all of its components, both kernel and
       userspace. This, along with an unified and easy to customize build
       system and a well thought out development process makes it easy to
       integrate FreeBSD with build infrastructure for your own product.

     * Staying true to Unix philosophy, preferring composability instead of
       monolithic "all in one" daemons with hardcoded behavior.

     * Binary compatibility with Linux, which makes it possible to run many
       Linux binaries without the need for virtualisation.

   FreeBSD is based on the 4.4BSD-Lite release from Computer Systems Research
   Group (CSRG) at the University of California at Berkeley, and carries on
   the distinguished tradition of BSD systems development. In addition to the
   fine work provided by CSRG, the FreeBSD Project has put in many thousands
   of man-hours into extending the functionality and fine-tuning the system
   for maximum performance and reliability in real-life load situations.
   FreeBSD offers performance and reliability on par with other Open Source
   and commercial offerings, combined with cutting-edge features not
   available anywhere else.

  1.2.1. What Can FreeBSD Do?

   The applications to which FreeBSD can be put are truly limited only by
   your own imagination. From software development to factory automation,
   inventory control to azimuth correction of remote satellite antennae; if
   it can be done with a commercial UNIX(R) product then it is more than
   likely that you can do it with FreeBSD too! FreeBSD also benefits
   significantly from literally thousands of high quality applications
   developed by research centers and universities around the world, often
   available at little to no cost.

   Because the source code for FreeBSD itself is freely available, the system
   can also be customized to an almost unheard of degree for special
   applications or projects, and in ways not generally possible with
   operating systems from most major commercial vendors. Here is just a
   sampling of some of the applications in which people are currently using
   FreeBSD:

     * Internet Services: The robust TCP/IP networking built into FreeBSD
       makes it an ideal platform for a variety of Internet services such as:

          * Web servers

          * IPv4 and IPv6 routing

          * Firewalls and NAT ("IP masquerading") gateways

          * FTP servers

          * Email servers

          * And more...

     * Education: Are you a student of computer science or a related
       engineering field? There is no better way of learning about operating
       systems, computer architecture and networking than the hands on, under
       the hood experience that FreeBSD can provide. A number of freely
       available CAD, mathematical and graphic design packages also make it
       highly useful to those whose primary interest in a computer is to get
       other work done!

     * Research: With source code for the entire system available, FreeBSD is
       an excellent platform for research in operating systems as well as
       other branches of computer science. FreeBSD's freely available nature
       also makes it possible for remote groups to collaborate on ideas or
       shared development without having to worry about special licensing
       agreements or limitations on what may be discussed in open forums.

     * Networking: Need a new router? A name server (DNS)? A firewall to keep
       people out of your internal network? FreeBSD can easily turn that
       unused PC sitting in the corner into an advanced router with
       sophisticated packet-filtering capabilities.

     * Embedded: FreeBSD makes an excellent platform to build embedded
       systems upon. With support for the ARM(R), MIPS(R) and PowerPC(R)
       platforms, coupled with a robust network stack, cutting edge features
       and the permissive BSD license FreeBSD makes an excellent foundation
       for building embedded routers, firewalls, and other devices.

     * Desktop: FreeBSD makes a fine choice for an inexpensive desktop
       solution using the freely available X11 server. FreeBSD offers a
       choice from many open-source desktop environments, including the
       standard GNOME and KDE graphical user interfaces. FreeBSD can even
       boot "diskless" from a central server, making individual workstations
       even cheaper and easier to administer.

     * Software Development: The basic FreeBSD system comes with a full suite
       of development tools including a full C/C++ compiler and debugger
       suite. Support for many other languages are also available through the
       ports and packages collection.

   FreeBSD is available to download free of charge, or can be obtained on
   either CD-ROM or DVD. Please see Appendix A, Obtaining FreeBSD for more
   information about obtaining FreeBSD.

  1.2.2. Who Uses FreeBSD?

   FreeBSD has been known for its web serving capabilities - sites that run
   on FreeBSD include Hacker News, Netcraft, NetEase, Netflix, Sina, Sony
   Japan, Rambler, Yahoo!, and Yandex.

   FreeBSD's advanced features, proven security, predictable release cycle,
   and permissive license have led to its use as a platform for building many
   commercial and open source appliances, devices, and products. Many of the
   world's largest IT companies use FreeBSD:

     * Apache - The Apache Software Foundation runs most of its public facing
       infrastructure, including possibly one of the largest SVN repositories
       in the world with over 1.4 million commits, on FreeBSD.

     * Apple - OS X borrows heavily from FreeBSD for the network stack,
       virtual file system, and many userland components. Apple iOS also
       contains elements borrowed from FreeBSD.

     * Cisco - IronPort network security and anti-spam appliances run a
       modified FreeBSD kernel.

     * Citrix - The NetScaler line of security appliances provide layer 4-7
       load balancing, content caching, application firewall, secure VPN, and
       mobile cloud network access, along with the power of a FreeBSD shell.

     * Dell EMC Isilon - Isilon's enterprise storage appliances are based on
       FreeBSD. The extremely liberal FreeBSD license allowed Isilon to
       integrate their intellectual property throughout the kernel and focus
       on building their product instead of an operating system.

     * Quest KACE - The KACE system management appliances run FreeBSD because
       of its reliability, scalability, and the community that supports its
       continued development.

     * iXsystems - The TrueNAS line of unified storage appliances is based on
       FreeBSD. In addition to their commercial products, iXsystems also
       manages development of the open source projects TrueOS and FreeNAS.

     * Juniper - The JunOS operating system that powers all Juniper
       networking gear (including routers, switches, security, and networking
       appliances) is based on FreeBSD. Juniper is one of many vendors that
       showcases the symbiotic relationship between the project and vendors
       of commercial products. Improvements generated at Juniper are
       upstreamed into FreeBSD to reduce the complexity of integrating new
       features from FreeBSD back into JunOS in the future.

     * McAfee - SecurOS, the basis of McAfee enterprise firewall products
       including Sidewinder is based on FreeBSD.

     * NetApp - The Data ONTAP GX line of storage appliances are based on
       FreeBSD. In addition, NetApp has contributed back many features,
       including the new BSD licensed hypervisor, bhyve.

     * Netflix - The OpenConnect appliance that Netflix uses to stream movies
       to its customers is based on FreeBSD. Netflix has made extensive
       contributions to the codebase and works to maintain a zero delta from
       mainline FreeBSD. Netflix OpenConnect appliances are responsible for
       delivering more than 32% of all Internet traffic in North America.

     * Sandvine - Sandvine uses FreeBSD as the basis of their high
       performance real-time network processing platforms that make up their
       intelligent network policy control products.

     * Sony - The PlayStation 4 gaming console runs a modified version of
       FreeBSD.

     * Sophos - The Sophos Email Appliance product is based on a hardened
       FreeBSD and scans inbound mail for spam and viruses, while also
       monitoring outbound mail for malware as well as the accidental loss of
       sensitive information.

     * Spectra Logic - The nTier line of archive grade storage appliances run
       FreeBSD and OpenZFS.

     * Stormshield - Stormshield Network Security appliances are based on a
       hardened version of FreeBSD. The BSD license allows them to integrate
       their own intellectual property with the system while returning a
       great deal of interesting development to the community.

     * The Weather Channel - The IntelliStar appliance that is installed at
       each local cable provider's headend and is responsible for injecting
       local weather forecasts into the cable TV network's programming runs
       FreeBSD.

     * Verisign - Verisign is responsible for operating the .com and .net
       root domain registries as well as the accompanying DNS infrastructure.
       They rely on a number of different network operating systems including
       FreeBSD to ensure there is no common point of failure in their
       infrastructure.

     * Voxer - Voxer powers their mobile voice messaging platform with ZFS on
       FreeBSD. Voxer switched from a Solaris derivative to FreeBSD because
       of its superior documentation, larger and more active community, and
       more developer friendly environment. In addition to critical features
       like ZFS and DTrace, FreeBSD also offers TRIM support for ZFS.

     * Fudo Security - The FUDO security appliance allows enterprises to
       monitor, control, record, and audit contractors and administrators who
       work on their systems. Based on all of the best security features of
       FreeBSD including ZFS, GELI, Capsicum, HAST, and auditdistd.

   FreeBSD has also spawned a number of related open source projects:

     * BSD Router - A FreeBSD based replacement for large enterprise routers
       designed to run on standard PC hardware.

     * FreeNAS - A customized FreeBSD designed to be used as a network file
       server appliance. Provides a python based web interface to simplify
       the management of both the UFS and ZFS file systems. Includes support
       for NFS, SMB/CIFS, AFP, FTP, and iSCSI. Includes an extensible plugin
       system based on FreeBSD jails.

     * GhostBSD - is derived from FreeBSD, uses the GTK environment to
       provide a beautiful looks and comfortable experience on the modern BSD
       platform offering a natural and native UNIX(R) work environment.

     * mfsBSD - A toolkit for building a FreeBSD system image that runs
       entirely from memory.

     * NAS4Free - A file server distribution based on FreeBSD with a PHP
       powered web interface.

     * OPNSense - OPNsense is an open source, easy-to-use and easy-to-build
       FreeBSD based firewall and routing platform. OPNsense includes most of
       the features available in expensive commercial firewalls, and more in
       many cases. It brings the rich feature set of commercial offerings
       with the benefits of open and verifiable sources.

     * TrueOS - TrueOS is based on the legendary security and stability of
       FreeBSD. TrueOS follows FreeBSD-CURRENT, with the latest drivers,
       security updates, and packages available.

     * MidnightBSD - is a FreeBSD derived operating system developed with
       desktop users in mind. It includes all the software you'd expect for
       your daily tasks: mail, web browsing, word processing, gaming, and
       much more.

     * NomadBSD - is a persistent live system for USB flash drives, based on
       FreeBSD. Together with automatic hardware detection and setup, it is
       configured to be used as a desktop system that works out of the box,
       but can also be used for data recovery, for educational purposes, or
       to test FreeBSD's hardware compatibility.

     * pfSense - A firewall distribution based on FreeBSD with a huge array
       of features and extensive IPv6 support.

     * ZRouter - An open source alternative firmware for embedded devices
       based on FreeBSD. Designed to replace the proprietary firmware on
       off-the-shelf routers.

   A list of testimonials from companies basing their products and services
   on FreeBSD can be found at the FreeBSD Foundation website. Wikipedia also
   maintains a list of products based on FreeBSD.

1.3. About the FreeBSD Project

   The following section provides some background information on the project,
   including a brief history, project goals, and the development model of the
   project.

  1.3.1. A Brief History of FreeBSD

   The FreeBSD Project had its genesis in the early part of 1993, partially
   as the brainchild of the Unofficial 386BSDPatchkit's last 3 coordinators:
   Nate Williams, Rod Grimes and Jordan Hubbard.

   The original goal was to produce an intermediate snapshot of 386BSD in
   order to fix a number of problems that the patchkit mechanism was just not
   capable of solving. The early working title for the project was 386BSD 0.5
   or 386BSD Interim in reference of that fact.

   386BSD was Bill Jolitz's operating system, which had been up to that point
   suffering rather severely from almost a year's worth of neglect. As the
   patchkit swelled ever more uncomfortably with each passing day, they
   decided to assist Bill by providing this interim "cleanup" snapshot. Those
   plans came to a rude halt when Bill Jolitz suddenly decided to withdraw
   his sanction from the project without any clear indication of what would
   be done instead.

   The trio thought that the goal remained worthwhile, even without Bill's
   support, and so they adopted the name "FreeBSD" coined by David Greenman.
   The initial objectives were set after consulting with the system's current
   users and, once it became clear that the project was on the road to
   perhaps even becoming a reality, Jordan contacted Walnut Creek CDROM with
   an eye toward improving FreeBSD's distribution channels for those many
   unfortunates without easy access to the Internet. Walnut Creek CDROM not
   only supported the idea of distributing FreeBSD on CD but also went so far
   as to provide the project with a machine to work on and a fast Internet
   connection. Without Walnut Creek CDROM's almost unprecedented degree of
   faith in what was, at the time, a completely unknown project, it is quite
   unlikely that FreeBSD would have gotten as far, as fast, as it has today.

   The first CD-ROM (and general net-wide) distribution was FreeBSD 1.0,
   released in December of 1993. This was based on the 4.3BSD-Lite ("Net/2")
   tape from U.C. Berkeley, with many components also provided by 386BSD and
   the Free Software Foundation. It was a fairly reasonable success for a
   first offering, and they followed it with the highly successful FreeBSD
   1.1 release in May of 1994.

   Around this time, some rather unexpected storm clouds formed on the
   horizon as Novell and U.C. Berkeley settled their long-running lawsuit
   over the legal status of the Berkeley Net/2 tape. A condition of that
   settlement was U.C. Berkeley's concession that large parts of Net/2 were
   "encumbered" code and the property of Novell, who had in turn acquired it
   from AT&T some time previously. What Berkeley got in return was Novell's
   "blessing" that the 4.4BSD-Lite release, when it was finally released,
   would be declared unencumbered and all existing Net/2 users would be
   strongly encouraged to switch. This included FreeBSD, and the project was
   given until the end of July 1994 to stop shipping its own Net/2 based
   product. Under the terms of that agreement, the project was allowed one
   last release before the deadline, that release being FreeBSD 1.1.5.1.

   FreeBSD then set about the arduous task of literally re-inventing itself
   from a completely new and rather incomplete set of 4.4BSD-Lite bits. The
   "Lite" releases were light in part because Berkeley's CSRG had removed
   large chunks of code required for actually constructing a bootable running
   system (due to various legal requirements) and the fact that the Intel
   port of 4.4 was highly incomplete. It took the project until November of
   1994 to make this transition, and in December it released FreeBSD 2.0 to
   the world. Despite being still more than a little rough around the edges,
   the release was a significant success and was followed by the more robust
   and easier to install FreeBSD 2.0.5 release in June of 1995.

   Since that time, FreeBSD has made a series of releases each time improving
   the stability, speed, and feature set of the previous version.

   For now, long-term development projects continue to take place in the
   10.X-CURRENT (trunk) branch, and snapshot releases of 10.X are continually
   made available from the snapshot server as work progresses.

  1.3.2. FreeBSD Project Goals

   Contributed by Jordan Hubbard.

   The goals of the FreeBSD Project are to provide software that may be used
   for any purpose and without strings attached. Many of us have a
   significant investment in the code (and project) and would certainly not
   mind a little financial compensation now and then, but we are definitely
   not prepared to insist on it. We believe that our first and foremost
   "mission" is to provide code to any and all comers, and for whatever
   purpose, so that the code gets the widest possible use and provides the
   widest possible benefit. This is, I believe, one of the most fundamental
   goals of Free Software and one that we enthusiastically support.

   That code in our source tree which falls under the GNU General Public
   License (GPL) or Library General Public License (LGPL) comes with slightly
   more strings attached, though at least on the side of enforced access
   rather than the usual opposite. Due to the additional complexities that
   can evolve in the commercial use of GPL software we do, however, prefer
   software submitted under the more relaxed BSD license when it is a
   reasonable option to do so.

  1.3.3. The FreeBSD Development Model

   Contributed by Satoshi Asami.

   The development of FreeBSD is a very open and flexible process, being
   literally built from the contributions of thousands of people around the
   world, as can be seen from our list of contributors. FreeBSD's development
   infrastructure allow these thousands of contributors to collaborate over
   the Internet. We are constantly on the lookout for new developers and
   ideas, and those interested in becoming more closely involved with the
   project need simply contact us at the FreeBSD technical discussions
   mailing list. The FreeBSD announcements mailing list is also available to
   those wishing to make other FreeBSD users aware of major areas of work.

   Useful things to know about the FreeBSD Project and its development
   process, whether working independently or in close cooperation:

   The SVN repositories

           For several years, the central source tree for FreeBSD was
           maintained by CVS (Concurrent Versions System), a freely available
           source code control tool. In June 2008, the Project switched to
           using SVN (Subversion). The switch was deemed necessary, as the
           technical limitations imposed by CVS were becoming obvious due to
           the rapid expansion of the source tree and the amount of history
           already stored. The Documentation Project and Ports Collection
           repositories also moved from CVS to SVN in May 2012 and July 2012,
           respectively. Please refer to the Obtaining the Source section for
           more information on obtaining the FreeBSD src/ repository and
           Using the Ports Collection for details on obtaining the FreeBSD
           Ports Collection.

   The committers list

           The committers are the people who have write access to the
           Subversion tree, and are authorized to make modifications to the
           FreeBSD source (the term "committer" comes from commit, the source
           control command which is used to bring new changes into the
           repository). Anyone can submit a bug to the Bug Database. Before
           submitting a bug report, the FreeBSD mailing lists, IRC channels,
           or forums can be used to help verify that an issue is actually a
           bug.

   The FreeBSD core team

           The FreeBSD core team would be equivalent to the board of
           directors if the FreeBSD Project were a company. The primary task
           of the core team is to make sure the project, as a whole, is in
           good shape and is heading in the right directions. Inviting
           dedicated and responsible developers to join our group of
           committers is one of the functions of the core team, as is the
           recruitment of new core team members as others move on. The
           current core team was elected from a pool of committer candidates
           in June 2020. Elections are held every 2 years.

  Note:

           Like most developers, most members of the core team are also
           volunteers when it comes to FreeBSD development and do not benefit
           from the project financially, so "commitment" should also not be
           misconstrued as meaning "guaranteed support." The "board of
           directors" analogy above is not very accurate, and it may be more
           suitable to say that these are the people who gave up their lives
           in favor of FreeBSD against their better judgement!

   Outside contributors

           Last, but definitely not least, the largest group of developers
           are the users themselves who provide feedback and bug fixes to us
           on an almost constant basis. The primary way of keeping in touch
           with FreeBSD's more non-centralized development is to subscribe to
           the FreeBSD technical discussions mailing list where such things
           are discussed. See Appendix C, Resources on the Internet for more
           information about the various FreeBSD mailing lists.

           The FreeBSD Contributors List is a long and growing one, so why
           not join it by contributing something back to FreeBSD today?

           Providing code is not the only way of contributing to the project;
           for a more complete list of things that need doing, please refer
           to the FreeBSD Project web site.

   In summary, our development model is organized as a loose set of
   concentric circles. The centralized model is designed for the convenience
   of the users of FreeBSD, who are provided with an easy way of tracking one
   central code base, not to keep potential contributors out! Our desire is
   to present a stable operating system with a large set of coherent
   application programs that the users can easily install and use - this
   model works very well in accomplishing that.

   All we ask of those who would join us as FreeBSD developers is some of the
   same dedication its current people have to its continued success!

  1.3.4. Third Party Programs

   In addition to the base distributions, FreeBSD offers a ported software
   collection with thousands of commonly sought-after programs. At the time
   of this writing, there were over 24,000 ports! The list of ports ranges
   from http servers, to games, languages, editors, and almost everything in
   between. The entire Ports Collection requires approximately 500 MB. To
   compile a port, you simply change to the directory of the program you wish
   to install, type make install, and let the system do the rest. The full
   original distribution for each port you build is retrieved dynamically so
   you need only enough disk space to build the ports you want. Almost every
   port is also provided as a pre-compiled "package", which can be installed
   with a simple command (pkg install) by those who do not wish to compile
   their own ports from source. More information on packages and ports can be
   found in Chapter 4, Installing Applications: Packages and Ports.

  1.3.5. Additional Documentation

   All supported FreeBSD versions provide an option in the installer to
   install additional documentation under /usr/local/share/doc/freebsd during
   the initial system setup. Documentation may also be installed at any later
   time using packages as described in Section 24.3.2, "Updating
   Documentation from Ports". You may view the locally installed manuals with
   any HTML capable browser using the following URLs:

   The FreeBSD Handbook

           /usr/local/share/doc/freebsd/handbook/index.html

   The FreeBSD FAQ

           /usr/local/share/doc/freebsd/faq/index.html

   You can also view the master (and most frequently updated) copies at
   https://www.FreeBSD.org/.

Chapter 2. Installing FreeBSD

   Restructured, reorganized, and parts rewritten by Jim Mock.
   Updated for bsdinstall by Gavin Atkinson and Warren Block.
   Updated for root-on-ZFS by Allan Jude.
   Table of Contents

   2.1. Synopsis

   2.2. Minimum Hardware Requirements

   2.3. Pre-Installation Tasks

   2.4. Starting the Installation

   2.5. Using bsdinstall

   2.6. Allocating Disk Space

   2.7. Fetching Distribution Files

   2.8. Accounts, Time Zone, Services and Hardening

   2.9. Network Interfaces

   2.10. Troubleshooting

   2.11. Using the Live CD

2.1. Synopsis

   There are several different ways of getting FreeBSD to run, depending on
   the environment. Those are:

     * Virtual Machine images, to download and import on a virtual
       environment of choice. These can be downloaded from the Download
       FreeBSD page. There are images for KVM ("qcow2"), VMWare ("vmdk"),
       Hyper-V ("vhd"), and raw device images that are universally supported.
       These are not installation images, but rather the preconfigured
       ("already installed") instances, ready to run and perform
       post-installation tasks.

     * Virtual Machine images available at Amazon's AWS Marketplace,
       Microsoft Azure Marketplace, and Google Cloud Platform, to run on
       their respective hosting services. For more information on deploying
       FreeBSD on Azure please consult the relevant chapter in the Azure
       Documentation.

     * SD card images, for embedded systems such as Raspberry Pi or
       BeagleBone Black. These can be downloaded from the Download FreeBSD
       page. These files must be uncompressed and written as a raw image to
       an SD card, from which the board will then boot.

     * Installation images, to install FreeBSD on a hard drive for the usual
       desktop, laptop, or server systems.

   The rest of this chapter describes the fourth case, explaining how to
   install FreeBSD using the text-based installation program named
   bsdinstall.

   In general, the installation instructions in this chapter are written for
   the i386(TM) and AMD64 architectures. Where applicable, instructions
   specific to other platforms will be listed. There may be minor differences
   between the installer and what is shown here, so use this chapter as a
   general guide rather than as a set of literal instructions.

  Note:

   Users who prefer to install FreeBSD using a graphical installer may be
   interested in GhostBSD, MidnightBSD or NomadBSD.

   After reading this chapter, you will know:

     * The minimum hardware requirements and FreeBSD supported architectures.

     * How to create the FreeBSD installation media.

     * How to start bsdinstall.

     * The questions bsdinstall will ask, what they mean, and how to answer
       them.

     * How to troubleshoot a failed installation.

     * How to access a live version of FreeBSD before committing to an
       installation.

   Before reading this chapter, you should:

     * Read the supported hardware list that shipped with the version of
       FreeBSD to be installed and verify that the system's hardware is
       supported.

2.2. Minimum Hardware Requirements

   The hardware requirements to install FreeBSD vary by architecture.
   Hardware architectures and devices supported by a FreeBSD release are
   listed on the FreeBSD Release Information page. The FreeBSD download page
   also has recommendations for choosing the correct image for different
   architectures.

   A FreeBSD installation requires a minimum of 96 MB of RAM and 1.5 GB of
   free hard drive space. However, such small amounts of memory and disk
   space are really only suitable for custom applications like embedded
   appliances. General-purpose desktop systems need more resources. 2-4 GB
   RAM and at least 8 GB hard drive space is a good starting point.

   These are the processor requirements for each architecture:

   amd64

           This is the most common desktop and laptop processor type, used in
           most modern systems. Intel(R) calls it Intel64. Other
           manufacturers sometimes call it x86-64.

           Examples of amd64 compatible processors include: AMD Athlon(TM)64,
           AMD Opteron(TM), multi-core Intel(R) Xeon(TM), and
           Intel(R) Core(TM) 2 and later processors.

   i386

           Older desktops and laptops often use this 32-bit, x86
           architecture.

           Almost all i386-compatible processors with a floating point unit
           are supported. All Intel(R) processors 486 or higher are
           supported.

           FreeBSD will take advantage of Physical Address Extensions (PAE)
           support on CPUs with this feature. A kernel with the PAE feature
           enabled will detect memory above 4 GB and allow it to be used by
           the system. However, using PAE places constraints on device
           drivers and other features of FreeBSD.

   powerpc

           All New World ROM Apple(R) Mac(R) systems with built-in USB are
           supported. SMP is supported on machines with multiple CPUs.

           A 32-bit kernel can only use the first 2 GB of RAM.

   sparc64

           Systems supported by FreeBSD/sparc64 are listed at the
           FreeBSD/sparc64 Project.

           SMP is supported on all systems with more than 1 processor. A
           dedicated disk is required as it is not possible to share a disk
           with another operating system at this time.

2.3. Pre-Installation Tasks

   Once it has been determined that the system meets the minimum hardware
   requirements for installing FreeBSD, the installation file should be
   downloaded and the installation media prepared. Before doing this, check
   that the system is ready for an installation by verifying the items in
   this checklist:

    1. Back Up Important Data

       Before installing any operating system, always backup all important
       data first. Do not store the backup on the system being installed.
       Instead, save the data to a removable disk such as a USB drive,
       another system on the network, or an online backup service. Test the
       backup before starting the installation to make sure it contains all
       of the needed files. Once the installer formats the system's disk, all
       data stored on that disk will be lost.

    2. Decide Where to Install FreeBSD

       If FreeBSD will be the only operating system installed, this step can
       be skipped. But if FreeBSD will share the disk with another operating
       system, decide which disk or partition will be used for FreeBSD.

       In the i386 and amd64 architectures, disks can be divided into
       multiple partitions using one of two partitioning schemes. A
       traditional Master Boot Record (MBR) holds a partition table defining
       up to four primary partitions. For historical reasons, FreeBSD calls
       these primary partition slices. One of these primary partitions can be
       made into an extended partition containing multiple logical
       partitions. The GUID Partition Table (GPT) is a newer and simpler
       method of partitioning a disk. Common GPT implementations allow up to
       128 partitions per disk, eliminating the need for logical partitions.

       The FreeBSD boot loader requires either a primary or GPT partition. If
       all of the primary or GPT partitions are already in use, one must be
       freed for FreeBSD. To create a partition without deleting existing
       data, use a partition resizing tool to shrink an existing partition
       and create a new partition using the freed space.

       A variety of free and commercial partition resizing tools are listed
       at http://en.wikipedia.org/wiki/List_of_disk_partitioning_software.
       GParted Live (http://gparted.sourceforge.net/livecd.php) is a free
       live CD which includes the GParted partition editor. GParted is also
       included with many other Linux live CD distributions.

  Warning:

       When used properly, disk shrinking utilities can safely create space
       for creating a new partition. Since the possibility of selecting the
       wrong partition exists, always backup any important data and verify
       the integrity of the backup before modifying disk partitions.

       Disk partitions containing different operating systems make it
       possible to install multiple operating systems on one computer. An
       alternative is to use virtualization (Chapter 22, Virtualization)
       which allows multiple operating systems to run at the same time
       without modifying any disk partitions.

    3. Collect Network Information

       Some FreeBSD installation methods require a network connection in
       order to download the installation files. After any installation, the
       installer will offer to setup the system's network interfaces.

       If the network has a DHCP server, it can be used to provide automatic
       network configuration. If DHCP is not available, the following network
       information for the system must be obtained from the local network
       administrator or Internet service provider:

       Required Network Information
         1. IP address

         2. Subnet mask

         3. IP address of default gateway

         4. Domain name of the network

         5. IP addresses of the network's DNS servers

    4. Check for FreeBSD Errata

       Although the FreeBSD Project strives to ensure that each release of
       FreeBSD is as stable as possible, bugs occasionally creep into the
       process. On very rare occasions those bugs affect the installation
       process. As these problems are discovered and fixed, they are noted in
       the FreeBSD Errata
       (https://www.freebsd.org/releases/12.1R/errata.html) on the FreeBSD
       web site. Check the errata before installing to make sure that there
       are no problems that might affect the installation.

       Information and errata for all the releases can be found on the
       release information section of the FreeBSD web site
       (https://www.freebsd.org/releases/index.html).

  2.3.1. Prepare the Installation Media

   The FreeBSD installer is not an application that can be run from within
   another operating system. Instead, download a FreeBSD installation file,
   burn it to the media associated with its file type and size (CD, DVD, or
   USB), and boot the system to install from the inserted media.

   FreeBSD installation files are available at
   www.freebsd.org/where.html#download. Each installation file's name
   includes the release version of FreeBSD, the architecture, and the type of
   file. For example, to install FreeBSD 12.1 on an amd64 system from a DVD,
   download FreeBSD-12.1-RELEASE-amd64-dvd1.iso, burn this file to a DVD, and
   boot the system with the DVD inserted.

   Installation files are available in several formats. The formats vary
   depending on computer architecture and media type.

   Additional installation files are included for computers that boot with
   UEFI (Unified Extensible Firmware Interface). The names of these files
   include the string uefi.

   File types:

     * -bootonly.iso: This is the smallest installation file as it only
       contains the installer. A working Internet connection is required
       during installation as the installer will download the files it needs
       to complete the FreeBSD installation. This file should be burned to a
       CD using a CD burning application.

     * -disc1.iso: This file contains all of the files needed to install
       FreeBSD, its source, and the Ports Collection. It should be burned to
       a CD using a CD burning application.

     * -dvd1.iso: This file contains all of the files needed to install
       FreeBSD, its source, and the Ports Collection. It also contains a set
       of popular binary packages for installing a window manager and some
       applications so that a complete system can be installed from media
       without requiring a connection to the Internet. This file should be
       burned to a DVD using a DVD burning application.

     * -memstick.img: This file contains all of the files needed to install
       FreeBSD, its source, and the Ports Collection. It should be burned to
       a USB stick using the instructions below.

     * -mini-memstick.img: Like -bootonly.iso, does not include installation
       files, but downloads them as needed. A working internet connection is
       required during installation. Write this file to a USB stick as shown
       in Section 2.3.1.1, "Writing an Image File to USB".

   After downloading the image file, download CHECKSUM.SHA256 from the same
   directory. Calculate a checksum for the image file. FreeBSD provides
   sha256(1) for this, used as sha256 imagefilename. Other operating systems
   have similar programs.

   Compare the calculated checksum with the one shown in CHECKSUM.SHA256. The
   checksums must match exactly. If the checksums do not match, the image
   file is corrupt and must be downloaded again.

    2.3.1.1. Writing an Image File to USB

   The *.img file is an image of the complete contents of a memory stick. It
   cannot be copied to the target device as a file. Several applications are
   available for writing the *.img to a USB stick. This section describes two
   of these utilities.

  Important:

   Before proceeding, back up any important data on the USB stick. This
   procedure will erase the existing data on the stick.

   Procedure 2.1. Using dd to Write the Image

  Warning:

   This example uses /dev/da0 as the target device where the image will be
   written. Be very careful that the correct device is used as this command
   will destroy the existing data on the specified target device.

     * The dd(1) command-line utility is available on BSD, Linux(R), and
       Mac OS(R) systems. To burn the image using dd, insert the USB stick
       and determine its device name. Then, specify the name of the
       downloaded installation file and the device name for the USB stick.
       This example burns the amd64 installation image to the first USB
       device on an existing FreeBSD system.

 # dd if=FreeBSD-12.1-RELEASE-amd64-memstick.img of=/dev/da0 bs=1M conv=sync

       If this command fails, verify that the USB stick is not mounted and
       that the device name is for the disk, not a partition. Some operating
       systems might require this command to be run with sudo(8). The dd(1)
       syntax varies slightly across different platforms; for example,
       Mac OS(R) requires a lower-case bs=1m. Systems like Linux(R) might
       buffer writes. To force all writes to complete, use sync(8).

   Procedure 2.2. Using Windows(R) to Write the Image

  Warning:

   Be sure to give the correct drive letter as the existing data on the
   specified drive will be overwritten and destroyed.

    1. Obtaining Image Writer for Windows(R)

       Image Writer for Windows(R) is a free application that can correctly
       write an image file to a memory stick. Download it from
       https://sourceforge.net/projects/win32diskimager/ and extract it into
       a folder.

    2. Writing the Image with Image Writer

       Double-click the Win32DiskImager icon to start the program. Verify
       that the drive letter shown under Device is the drive with the memory
       stick. Click the folder icon and select the image to be written to the
       memory stick. Click [ Save ] to accept the image file name. Verify
       that everything is correct, and that no folders on the memory stick
       are open in other windows. When everything is ready, click [ Write ]
       to write the image file to the memory stick.

   You are now ready to start installing FreeBSD.

2.4. Starting the Installation

  Important:

   By default, the installation will not make any changes to the disk(s)
   before the following message:

 Your changes will now be written to disk. If you
 have chosen to overwrite existing data, it will
 be PERMANENTLY ERASED. Are you sure you want to
 commit your changes?

   The install can be exited at any time prior to this warning. If there is a
   concern that something is incorrectly configured, just turn the computer
   off before this point and no changes will be made to the system's disks.

   This section describes how to boot the system from the installation media
   which was prepared using the instructions in Section 2.3.1, "Prepare the
   Installation Media". When using a bootable USB stick, plug in the USB
   stick before turning on the computer. When booting from CD or DVD, turn on
   the computer and insert the media at the first opportunity. How to
   configure the system to boot from the inserted media depends upon the
   architecture.

  2.4.1. Booting on i386(TM) and amd64

   These architectures provide a BIOS menu for selecting the boot device.
   Depending upon the installation media being used, select the CD/DVD or USB
   device as the first boot device. Most systems also provide a key for
   selecting the boot device during startup without having to enter the BIOS.
   Typically, the key is either F10, F11, F12, or Escape.

   If the computer loads the existing operating system instead of the FreeBSD
   installer, then either:

    1. The installation media was not inserted early enough in the boot
       process. Leave the media inserted and try restarting the computer.

    2. The BIOS changes were incorrect or not saved. Double-check that the
       right boot device is selected as the first boot device.

    3. This system is too old to support booting from the chosen media. In
       this case, the Plop Boot Manager
       (http://www.plop.at/en/bootmanagers.html) can be used to boot the
       system from the selected media.

  2.4.2. Booting on PowerPC(R)

   On most machines, holding C on the keyboard during boot will boot from the
   CD. Otherwise, hold Command+Option+O+F, or Windows+Alt+O+F on non-Apple(R)
   keyboards. At the 0 > prompt, enter

 boot cd:,\ppc\loader cd:0

  2.4.3. FreeBSD Boot Menu

   Once the system boots from the installation media, a menu similar to the
   following will be displayed:

   Figure 2.1. FreeBSD Boot Loader Menu
   FreeBSD Boot Loader Menu

   By default, the menu will wait ten seconds for user input before booting
   into the FreeBSD installer or, if FreeBSD is already installed, before
   booting into FreeBSD. To pause the boot timer in order to review the
   selections, press Space. To select an option, press its highlighted
   number, character, or key. The following options are available.

     * Boot Multi User: This will continue the FreeBSD boot process. If the
       boot timer has been paused, press 1, upper- or lower-case B, or Enter.

     * Boot Single User: This mode can be used to fix an existing FreeBSD
       installation as described in Section 13.2.4.1, "Single-User Mode".
       Press 2 or the upper- or lower-case S to enter this mode.

     * Escape to loader prompt: This will boot the system into a repair
       prompt that contains a limited number of low-level commands. This
       prompt is described in Section 13.2.3, "Stage Three". Press 3 or Esc
       to boot into this prompt.

     * Reboot: Reboots the system.

     * Kernel: Loads a different kernel.

     * Configure Boot Options: Opens the menu shown in, and described under,
       Figure 2.2, "FreeBSD Boot Options Menu".

   Figure 2.2. FreeBSD Boot Options Menu
   FreeBSD Boot Options Menu

   The boot options menu is divided into two sections. The first section can
   be used to either return to the main boot menu or to reset any toggled
   options back to their defaults.

   The next section is used to toggle the available options to On or Off by
   pressing the option's highlighted number or character. The system will
   always boot using the settings for these options until they are modified.
   Several options can be toggled using this menu:

     * ACPI Support: If the system hangs during boot, try toggling this
       option to Off.

     * Safe Mode: If the system still hangs during boot even with ACPI
       Support set to Off, try setting this option to On.

     * Single User: Toggle this option to On to fix an existing FreeBSD
       installation as described in Section 13.2.4.1, "Single-User Mode".
       Once the problem is fixed, set it back to Off.

     * Verbose: Toggle this option to On to see more detailed messages during
       the boot process. This can be useful when troubleshooting a piece of
       hardware.

   After making the needed selections, press 1 or Backspace to return to the
   main boot menu, then press Enter to continue booting into FreeBSD. A
   series of boot messages will appear as FreeBSD carries out its hardware
   device probes and loads the installation program. Once the boot is
   complete, the welcome menu shown in Figure 2.3, "Welcome Menu" will be
   displayed.

   Figure 2.3. Welcome Menu
   Welcome Menu

   Press Enter to select the default of [ Install ] to enter the installer.
   The rest of this chapter describes how to use this installer. Otherwise,
   use the right or left arrows or the colorized letter to select the desired
   menu item. The [ Shell ] can be used to access a FreeBSD shell in order to
   use command line utilities to prepare the disks before installation. The
   [ Live CD ] option can be used to try out FreeBSD before installing it.
   The live version is described in Section 2.11, "Using the Live CD".

  Tip:

   To review the boot messages, including the hardware device probe, press
   the upper- or lower-case S and then Enter to access a shell. At the shell
   prompt, type more /var/run/dmesg.boot and use the space bar to scroll
   through the messages. When finished, type exit to return to the welcome
   menu.

2.5. Using bsdinstall

   This section shows the order of the bsdinstall menus and the type of
   information that will be asked before the system is installed. Use the
   arrow keys to highlight a menu option, then Space to select or deselect
   that menu item. When finished, press Enter to save the selection and move
   onto the next screen.

  2.5.1. Selecting the Keymap Menu

   Before starting the process, bsdinstall will load the keymap files as show
   in Figure 2.4, "Keymap Loading".

   Figure 2.4. Keymap Loading
   Keymap Loading

   After the keymaps have been loaded bsdinstall displays the menu shown in
   Figure 2.5, "Keymap Selection Menu". Use the up and down arrows to select
   the keymap that most closely represents the mapping of the keyboard
   attached to the system. Press Enter to save the selection.

   Figure 2.5. Keymap Selection Menu
   Keymap Selection Menu

  Note:

   Pressing Esc will exit this menu and use the default keymap. If the choice
   of keymap is not clear, United States of America ISO-8859-1 is also a safe
   option.

   In addition, when selecting a different keymap, the user can try the
   keymap and ensure it is correct before proceeding as shown in Figure 2.6,
   "Keymap Testing Menu".

   Figure 2.6. Keymap Testing Menu
   Keymap Testing Menu

  2.5.2. Setting the Hostname

   The next bsdinstall menu is used to set the hostname for the newly
   installed system.

   Figure 2.7. Setting the Hostname
   Setting the Hostname

   Type in a hostname that is unique for the network. It should be a
   fully-qualified hostname, such as machine3.example.com.

  2.5.3. Selecting Components to Install

   Next, bsdinstall will prompt to select optional components to install.

   Figure 2.8. Selecting Components to Install
   Selecting Components to Install

   Deciding which components to install will depend largely on the intended
   use of the system and the amount of disk space available. The FreeBSD
   kernel and userland, collectively known as the base system, are always
   installed. Depending on the architecture, some of these components may not
   appear:

     * base-dbg - Base tools like cat, ls among many others with debug
       symbols activated.

     * kernel-dbg - Kernel and modules with debug symbols activated.

     * lib32-dbg - Compatibility libraries for running 32-bit applications on
       a 64-bit version of FreeBSD with debug symbols activated.

     * lib32 - Compatibility libraries for running 32-bit applications on a
       64-bit version of FreeBSD.

     * ports - The FreeBSD Ports Collection is a collection of files which
       automates the downloading, compiling and installation of third-party
       software packages. Chapter 4, Installing Applications: Packages and
       Ports discusses how to use the Ports Collection.

  Warning:

       The installation program does not check for adequate disk space.
       Select this option only if sufficient hard disk space is available.
       The FreeBSD Ports Collection takes up about 500 MB of disk space.

     * src - The complete FreeBSD source code for both the kernel and the
       userland. Although not required for the majority of applications, it
       may be required to build device drivers, kernel modules, or some
       applications from the Ports Collection. It is also used for developing
       FreeBSD itself. The full source tree requires 1 GB of disk space and
       recompiling the entire FreeBSD system requires an additional 5 GB of
       space.

     * tests - FreeBSD Test Suite.

  2.5.4. Installing from the Network

   The menu shown in Figure 2.9, "Installing from the Network" only appears
   when installing from a -bootonly.iso or -mini-memstick.img as this
   installation media does not hold copies of the installation files. Since
   the installation files must be retrieved over a network connection, this
   menu indicates that the network interface must be configured first. If
   this menu is shown in any step of the process remember to follow the
   instructions in Section 2.9.1, "Configuring Network Interfaces".

   Figure 2.9. Installing from the Network
   Installing from the Network

2.6. Allocating Disk Space

   The next menu is used to determine the method for allocating disk space.

   Figure 2.10. Partitioning Choices
   Partitioning Choices

   bsdinstall gives the user four methods for allocating disk space:

     * Auto (UFS) partitioning automatically sets up the disk partitions
       using the UFS file system.

     * Manual partitioning allows advanced users to create customized
       partitions from menu options.

     * Shell opens a shell prompt where advanced users can create customized
       partitions using command-line utilities like gpart(8), fdisk(8), and
       bsdlabel(8).

     * Auto (ZFS) partitioning creates a root-on-ZFS system with optional
       GELI encryption support for boot environments.

   This section describes what to consider when laying out the disk
   partitions. It then demonstrates how to use the different partitioning
   methods.

  2.6.1. Designing the Partition Layout

   When laying out file systems, remember that hard drives transfer data
   faster from the outer tracks to the inner. Thus, smaller and
   heavier-accessed file systems should be closer to the outside of the
   drive, while larger partitions like /usr should be placed toward the inner
   parts of the disk. It is a good idea to create partitions in an order
   similar to: /, swap, /var, and /usr.

   The size of the /var partition reflects the intended machine's usage. This
   partition is used to hold mailboxes, log files, and printer spools.
   Mailboxes and log files can grow to unexpected sizes depending on the
   number of users and how long log files are kept. On average, most users
   rarely need more than about a gigabyte of free disk space in /var.

  Note:

   Sometimes, a lot of disk space is required in /var/tmp. When new software
   is installed, the packaging tools extract a temporary copy of the packages
   under /var/tmp. Large software packages, like Firefox or LibreOffice may
   be tricky to install if there is not enough disk space under /var/tmp.

   The /usr partition holds many of the files which support the system,
   including the FreeBSD Ports Collection and system source code. At least 2
   gigabytes of space is recommended for this partition.

   When selecting partition sizes, keep the space requirements in mind.
   Running out of space in one partition while barely using another can be a
   hassle.

   As a rule of thumb, the swap partition should be about double the size of
   physical memory (RAM). Systems with minimal RAM may perform better with
   more swap. Configuring too little swap can lead to inefficiencies in the
   VM page scanning code and might create issues later if more memory is
   added.

   On larger systems with multiple SCSI disks or multiple IDE disks operating
   on different controllers, it is recommended that swap be configured on
   each drive, up to four drives. The swap partitions should be approximately
   the same size. The kernel can handle arbitrary sizes but internal data
   structures scale to 4 times the largest swap partition. Keeping the swap
   partitions near the same size will allow the kernel to optimally stripe
   swap space across disks. Large swap sizes are fine, even if swap is not
   used much. It might be easier to recover from a runaway program before
   being forced to reboot.

   By properly partitioning a system, fragmentation introduced in the smaller
   write heavy partitions will not bleed over into the mostly read
   partitions. Keeping the write loaded partitions closer to the disk's edge
   will increase I/O performance in the partitions where it occurs the most.
   While I/O performance in the larger partitions may be needed, shifting
   them more toward the edge of the disk will not lead to a significant
   performance improvement over moving /var to the edge.

  2.6.2. Guided Partitioning Using UFS

   When this method is selected, a menu will display the available disk(s).
   If multiple disks are connected, choose the one where FreeBSD is to be
   installed.

   Figure 2.11. Selecting from Multiple Disks
   Selecting from Multiple Disks

   Once the disk is selected, the next menu prompts to install to either the
   entire disk or to create a partition using free space. If [ Entire Disk ]
   is chosen, a general partition layout filling the whole disk is
   automatically created. Selecting [ Partition ] creates a partition layout
   from the unused space on the disk.

   Figure 2.12. Selecting Entire Disk or Partition
   Selecting Entire Disk or Partition

   After [ Entire Disk ] is chosen bsdinstall displays a dialog indicating
   that the disk will be erased.

   Figure 2.13. Confirmation
   Confirmation

   The next menu shows a list with the partition schemes types. GPT is
   usually the most appropriate choice for amd64 computers. Older computers
   that are not compatible with GPT should use MBR. The other partition
   schemes are generally used for uncommon or older computers. More
   information is available in Table 2.1, "Partitioning Schemes".

   Figure 2.14. Select Partition Scheme
   Select Partition Scheme

   After the partition layout has been created, review it to ensure it meets
   the needs of the installation. Selecting [ Revert ] will reset the
   partitions to their original values and pressing [ Auto ] will recreate
   the automatic FreeBSD partitions. Partitions can also be manually created,
   modified, or deleted. When the partitioning is correct, select [ Finish ]
   to continue with the installation.

   Figure 2.15. Review Created Partitions
   Review Created Partitions

   Once the disks are configured, the next menu provides the last chance to
   make changes before the selected drives are formatted. If changes need to
   be made, select [ Back ] to return to the main partitioning menu.
   [ Revert & Exit ] exits the installer without making any changes to the
   drive. Select [ Commit ] to start the installation process.

   Figure 2.16. Final Confirmation
   Final Confirmation

   To continue with the installation process go to Section 2.7, "Fetching
   Distribution Files".

  2.6.3. Manual Partitioning

   Selecting this method opens the partition editor:

   Figure 2.17. Manually Create Partitions
   Manually Create Partitions

   Highlight the installation drive (ada0 in this example) and select
   [ Create ] to display a menu of available partition schemes:

   Figure 2.18. Manually Create Partitions
   Manually Create Partitions

   GPT is usually the most appropriate choice for amd64 computers. Older
   computers that are not compatible with GPT should use MBR. The other
   partition schemes are generally used for uncommon or older computers.

   Table 2.1. Partitioning Schemes

   Abbreviation Description                                                   
   APM          Apple Partition Map, used by PowerPC(R).                      
                BSD label without an MBR, sometimes called dangerously        
   BSD          dedicated mode as non-BSD disk utilities may not recognize    
                it.                                                           
   GPT          GUID Partition Table                                          
                (http://en.wikipedia.org/wiki/GUID_Partition_Table).          
   MBR          Master Boot Record                                            
                (http://en.wikipedia.org/wiki/Master_boot_record).            
   VTOC8        Volume Table Of Contents used by Sun SPARC64 and UltraSPARC   
                computers.                                                    

   After the partitioning scheme has been selected and created, select
   [ Create ] again to create the partitions. The Tab key is used to move the
   cursor between fields.

   Figure 2.19. Manually Create Partitions
   Manually Create Partitions

   A standard FreeBSD GPT installation uses at least three partitions:

     * freebsd-boot - Holds the FreeBSD boot code.

     * freebsd-ufs - A FreeBSD UFS file system.

     * freebsd-zfs - A FreeBSD ZFS file system. More information about ZFS is
       available in Chapter 20, The Z File System (ZFS).

     * freebsd-swap - FreeBSD swap space.

   Refer to gpart(8) for descriptions of the available GPT partition types.

   Multiple file system partitions can be created and some people prefer a
   traditional layout with separate partitions for /, /var, /tmp, and /usr.
   See Example 2.1, "Creating Traditional Split File System Partitions" for
   an example.

   The Size may be entered with common abbreviations: K for kilobytes, M for
   megabytes, or G for gigabytes.

  Tip:

   Proper sector alignment provides the best performance, and making
   partition sizes even multiples of 4K bytes helps to ensure alignment on
   drives with either 512-byte or 4K-byte sectors. Generally, using partition
   sizes that are even multiples of 1M or 1G is the easiest way to make sure
   every partition starts at an even multiple of 4K. There is one exception:
   the freebsd-boot partition should be no larger than 512K due to current
   boot code limitations.

   A Mountpoint is needed if the partition will contain a file system. If
   only a single UFS partition will be created, the mountpoint should be /.

   The Label is a name by which the partition will be known. Drive names or
   numbers can change if the drive is connected to a different controller or
   port, but the partition label does not change. Referring to labels instead
   of drive names and partition numbers in files like /etc/fstab makes the
   system more tolerant to hardware changes. GPT labels appear in /dev/gpt/
   when a disk is attached. Other partitioning schemes have different label
   capabilities and their labels appear in different directories in /dev/.

  Tip:

   Use a unique label on every partition to avoid conflicts from identical
   labels. A few letters from the computer's name, use, or location can be
   added to the label. For instance, use labroot or rootfslab for the UFS
   root partition on the computer named lab.

   Example 2.1. Creating Traditional Split File System Partitions

   For a traditional partition layout where the /, /var, /tmp, and /usr
   directories are separate file systems on their own partitions, create a
   GPT partitioning scheme, then create the partitions as shown. Partition
   sizes shown are typical for a 20G target disk. If more space is available
   on the target disk, larger swap or /var partitions may be useful. Labels
   shown here are prefixed with ex for "example", but readers should use
   other unique label values as described above.

   By default, FreeBSD's gptboot expects the first UFS partition to be the /
   partition.

   Partition Type                  Size                   Mountpoint  Label   
   freebsd-boot   512K                                                        
   freebsd-ufs    2G                                      /          exrootfs 
   freebsd-swap   4G                                                 exswap   
   freebsd-ufs    2G                                      /var       exvarfs  
   freebsd-ufs    1G                                      /tmp       extmpfs  
   freebsd-ufs    accept the default (remainder of the    /usr       exusrfs  
                  disk)                                   

   After the custom partitions have been created, select [ Finish ] to
   continue with the installation and go to Section 2.7, "Fetching
   Distribution Files".

  2.6.4. Guided Partitioning Using Root-on-ZFS

   This partitioning mode only works with whole disks and will erase the
   contents of the entire disk. The main ZFS configuration menu offers a
   number of options to control the creation of the pool.

   Figure 2.20. ZFS Partitioning Menu
   ZFS Partitioning Menu

   Here is a summary of the options which can be used in this menu:

     * Install - Proceed with the installation with the selected options.

     * Pool Type/Disks - Allow to configure the Pool Type and the disk(s)
       that will constitute the pool. The automatic ZFS installer currently
       only supports the creation of a single top level vdev, except in
       stripe mode. To create more complex pools, use the instructions in
       Section 2.6.5, "Shell Mode Partitioning" to create the pool.

     * Rescan Devices - Repopulate the list of available disks.

     * Disk Info - Disk Info menu can be used to inspect each disk, including
       its partition table and various other information such as the device
       model number and serial number, if available.

     * Pool Name - Establish the name of the pool. The default name is zroot.

     * Force 4K Sectors? - Force the use of 4K sectors. By default, the
       installer will automatically create partitions aligned to 4K
       boundaries and force ZFS to use 4K sectors. This is safe even with 512
       byte sector disks, and has the added benefit of ensuring that pools
       created on 512 byte disks will be able to have 4K sector disks added
       in the future, either as additional storage space or as replacements
       for failed disks. Press the Enter key to chose to activate it or not.

     * Encrypt Disks? - Encrypting the disks allows the user to encrypt the
       disks using GELI. More information about disk encryption is available
       in Section 18.12.2, "Disk Encryption with geli". Press the Enter key
       to chose activate it or not.

     * Partition Scheme - Allow to choose the partition scheme. GPT is the
       recommended option in most cases. Press the Enter key to chose between
       the different options.

     * Swap Size - Establish the amount of swap space.

     * Mirror Swap? - Allows the user to mirror the swap between the disks.
       Be aware, enabling mirror swap will break crash dumps. Press the Enter
       key to activate it or not.

     * Encrypt Swap? - Allow the user the possibility to encrypt the swap.
       Encrypts the swap with a temporary key each time that the system boots
       and discards it on reboot. Press the Enter key to chose activate it or
       not. More information about swap encryption in Section 18.13,
       "Encrypting Swap".

   Select T to configure the Pool Type and the disk(s) that will constitute
   the pool.

   Figure 2.21. ZFS Pool Type
   ZFS Pool Type

   Here is a summary of the Pool Type which can be selected in this menu:

     * stripe - Striping provides maximum storage of all connected devices,
       but no redundancy. If just one disk fails the data on the pool is lost
       irrevocably.

     * mirror - Mirroring stores a complete copy of all data on every disk.
       Mirroring provides a good read performance because data is read from
       all disks in parallel. Write performance is slower as the data must be
       written to all disks in the pool. Allows all but one disk to fail.
       This option requires at least two disks.

     * raid10 - Striped mirrors. Provides the best performance, but the least
       storage. This option needs at least an even number of disks and a
       minimum of four disks.

     * raidz1 - Single Redundant RAID. Allow one disk to fail concurrently.
       This option needs at least three disks.

     * raidz2 - Double Redundant RAID. Allows two disks to fail concurrently.
       This option needs at least four disks.

     * raidz3 - Triple Redundant RAID. Allows three disks to fail
       concurrently. This option needs at least five disks.

   Once a Pool Type has been selected, a list of available disks is
   displayed, and the user is prompted to select one or more disks to make up
   the pool. The configuration is then validated, to ensure enough disks are
   selected. If not, select <Change Selection> to return to the list of
   disks, or <Back> to change the Pool Type.

   Figure 2.22. Disk Selection
   Disk Selection
   Figure 2.23. Invalid Selection
   Invalid Selection

   If one or more disks are missing from the list, or if disks were attached
   after the installer was started, select - Rescan Devices to repopulate the
   list of available disks.

   Figure 2.24. Rescan Devices
   Rescan Devices

   To avoid accidentally erasing the wrong disk, the - Disk Info menu can be
   used to inspect each disk, including its partition table and various other
   information such as the device model number and serial number, if
   available.

   Figure 2.25. Analyzing a Disk
   Analyzing a Disk

   Select N to configure the Pool Name. Enter the desired name then select
   <OK> to establish it or <Cancel> to return to the main menu and leave the
   default name.

   Figure 2.26. Pool Name
   Pool Name

   Select S to set the amount of swap. Enter the desired amount of swap and
   then select <OK> to establish it or <Cancel> to return to the main menu
   and let the default amount.

   Figure 2.27. Swap Amount
   Swap Amount

   Once all options have been set to the desired values, select the
   >>> Install option at the top of the menu. The installer then offers a
   last chance to cancel before the contents of the selected drives are
   destroyed to create the ZFS pool.

   Figure 2.28. Last Chance
   Last Chance

   If GELI disk encryption was enabled, the installer will prompt twice for
   the passphrase to be used to encrypt the disks. And after that the
   initializing of the encryption begins.

   Figure 2.29. Disk Encryption Password
   Disk Encryption Password
   Figure 2.30. Initializing Encryption
   Initializing Encryption

   The installation then proceeds normally. To continue with the installation
   go to Section 2.7, "Fetching Distribution Files".

  2.6.5. Shell Mode Partitioning

   When creating advanced installations, the bsdinstall partitioning menus
   may not provide the level of flexibility required. Advanced users can
   select the Shell option from the partitioning menu in order to manually
   partition the drives, create the file system(s), populate
   /tmp/bsdinstall_etc/fstab, and mount the file systems under /mnt. Once
   this is done, type exit to return to bsdinstall and continue the
   installation.

2.7. Fetching Distribution Files

   Installation time will vary depending on the distributions chosen,
   installation media, and speed of the computer. A series of messages will
   indicate the progress.

   First, the installer formats the selected disk(s) and initializes the
   partitions. Next, in the case of a bootonly media or mini memstick, it
   downloads the selected components:

   Figure 2.31. Fetching Distribution Files
   Fetching Distribution Files

   Next, the integrity of the distribution files is verified to ensure they
   have not been corrupted during download or misread from the installation
   media:

   Figure 2.32. Verifying Distribution Files
   Verifying Distribution Files

   Finally, the verified distribution files are extracted to the disk:

   Figure 2.33. Extracting Distribution Files
   Extracting Distribution Files

   Once all requested distribution files have been extracted, bsdinstall
   displays the first post-installation configuration screen. The available
   post-configuration options are described in the next section.

2.8. Accounts, Time Zone, Services and Hardening

  2.8.1. Setting the root Password

   First, the root password must be set. While entering the password, the
   characters being typed are not displayed on the screen. After the password
   has been entered, it must be entered again. This helps prevent typing
   errors.

   Figure 2.34. Setting the root Password
   Setting the root Password

  2.8.2. Setting the Time Zone

   The next series of menus are used to determine the correct local time by
   selecting the geographic region, country, and time zone. Setting the time
   zone allows the system to automatically correct for regional time changes,
   such as daylight savings time, and perform other time zone related
   functions properly.

   The example shown here is for a machine located in the mainland time zone
   of Spain, Europe. The selections will vary according to the geographical
   location.

   Figure 2.35. Select a Region
   Select a Region

   The appropriate region is selected using the arrow keys and then pressing
   Enter.

   Figure 2.36. Select a Country
   Select a Country

   Select the appropriate country using the arrow keys and press Enter.

   Figure 2.37. Select a Time Zone
   Select a Time Zone

   The appropriate time zone is selected using the arrow keys and pressing
   Enter.

   Figure 2.38. Confirm Time Zone
   Confirm Time Zone

   Confirm the abbreviation for the time zone is correct.

   Figure 2.39. Select Date
   Select Date

   The appropriate date is selected using the arrow keys and then pressing
   [ Set Date ]. Otherwise, the date selection can be skipped by pressing
   [ Skip ].

   Figure 2.40. Select Time
   Select Time

   The appropriate time is selected using the arrow keys and then pressing
   [ Set Time ]. Otherwise, the time selection can be skipped by pressing
   [ Skip ].

  2.8.3. Enabling Services

   The next menu is used to configure which system services will be started
   whenever the system boots. All of these services are optional. Only start
   the services that are needed for the system to function.

   Figure 2.41. Selecting Additional Services to Enable
   Selecting Additional Services to Enable

   Here is a summary of the services which can be enabled in this menu:

     * local_unbound - Enable the DNS local unbound. It is necessary to keep
       in mind that this is the unbound of the base system and is only meant
       for use as a local caching forwarding resolver. If the objective is to
       set up a resolver for the entire network install dns/unbound.

     * sshd - The Secure Shell (SSH) daemon is used to remotely access a
       system over an encrypted connection. Only enable this service if the
       system should be available for remote logins.

     * moused - Enable this service if the mouse will be used from the
       command-line system console.

     * ntpdate - Enable the automatic clock synchronization at boot time. The
       functionality of this program is now available in the ntpd(8) daemon.
       After a suitable period of mourning, the ntpdate(8) utility will be
       retired.

     * ntpd - The Network Time Protocol (NTP) daemon for automatic clock
       synchronization. Enable this service if there is a Windows(R),
       Kerberos, or LDAP server on the network.

     * powerd - System power control utility for power control and energy
       saving.

     * dumpdev - Enabling crash dumps is useful in debugging issues with the
       system, so users are encouraged to enable crash dumps.

  2.8.4. Enabling Hardening Security Options

   The next menu is used to configure which security options will be enabled.
   All of these options are optional. But their use is encouraged.

   Figure 2.42. Selecting Hardening Security Options
   Selecting Hardening Security Options

   Here is a summary of the options which can be enabled in this menu:

     * hide_uids - Hide processes running as other users to prevent the
       unprivileged users to see other running processes in execution by
       other users (UID) preventing information leakage.

     * hide_gids - Hide processes running as other groups to prevent the
       unprivileged users to see other running processes in execution by
       other groups (GID) preventing information leakage.

     * hide_jail - Hide processes running in jails to prevent the
       unprivileged users to see processes running inside the jails.

     * read_msgbuf - Disabling reading kernel message buffer for unprivileged
       users prevent from using dmesg(8) to view messages from the kernel's
       log buffer.

     * proc_debug - Disabling process debugging facilities for unprivileged
       users disables a variety of unprivileged inter-process debugging
       services, including some procfs functionality, ptrace(), and ktrace().
       Please note that this will also prevent debugging tools, for instance
       lldb(1), truss(1), procstat(1), as well as some built-in debugging
       facilities in certain scripting language like PHP, etc., from working
       for unprivileged users.

     * random_pid - Randomize the PID of newly created processes.

     * clear_tmp - Clean /tmp when the system starts up.

     * disable_syslogd - Disable opening syslogd network socket. By default
       FreeBSD runs syslogd in a secure way with -s. That prevents the daemon
       from listening for incoming UDP requests at port 514. With this option
       enabled syslogd will run with the flag -ss which prevents syslogd from
       opening any port. To get more information consult syslogd(8).

     * disable_sendmail - Disable the sendmail mail transport agent.

     * secure_console - When this option is enabled, the prompt requests the
       root password when entering single-user mode.

     * disable_ddtrace - DTrace can run in a mode that will actually affect
       the running kernel. Destructive actions may not be used unless they
       have been explicitly enabled. To enable this option when using DTrace
       use -w. To get more information consult dtrace(1).

  2.8.5. Add Users

   The next menu prompts to create at least one user account. It is
   recommended to login to the system using a user account rather than as
   root. When logged in as root, there are essentially no limits or
   protection on what can be done. Logging in as a normal user is safer and
   more secure.

   Select [ Yes ] to add new users.

   Figure 2.43. Add User Accounts
   Add User Accounts

   Follow the prompts and input the requested information for the user
   account. The example shown in Figure 2.44, "Enter User Information"
   creates the asample user account.

   Figure 2.44. Enter User Information
   Enter User Information

   Here is a summary of the information to input:

     * Username - The name the user will enter to log in. A common convention
       is to use the first letter of the first name combined with the last
       name, as long as each username is unique for the system. The username
       is case sensitive and should not contain any spaces.

     * Full name - The user's full name. This can contain spaces and is used
       as a description for the user account.

     * Uid - User ID. Typically, this is left blank so the system will assign
       a value.

     * Login group - The user's group. Typically this is left blank to accept
       the default.

     * Invite user into other groups? - Additional groups to which the user
       will be added as a member. If the user needs administrative access,
       type wheel here.

     * Login class - Typically left blank for the default.

     * Shell - Type in one of the listed values to set the interactive shell
       for the user. Refer to Section 3.9, "Shells" for more information
       about shells.

     * Home directory - The user's home directory. The default is usually
       correct.

     * Home directory permissions - Permissions on the user's home directory.
       The default is usually correct.

     * Use password-based authentication? - Typically yes so that the user is
       prompted to input their password at login.

     * Use an empty password? - Typically no as it is insecure to have a
       blank password.

     * Use a random password? - Typically no so that the user can set their
       own password in the next prompt.

     * Enter password - The password for this user. Characters typed will not
       show on the screen.

     * Enter password again - The password must be typed again for
       verification.

     * Lock out the account after creation? - Typically no so that the user
       can login.

   After entering everything, a summary is shown for review. If a mistake was
   made, enter no and try again. If everything is correct, enter yes to
   create the new user.

   Figure 2.45. Exit User and Group Management
   Exit User and Group Management

   If there are more users to add, answer the Add another user? question with
   yes. Enter no to finish adding users and continue the installation.

   For more information on adding users and user management, see Section 3.3,
   "Users and Basic Account Management".

  2.8.6. Final Configuration

   After everything has been installed and configured, a final chance is
   provided to modify settings.

   Figure 2.46. Final Configuration
   Final Configuration

   Use this menu to make any changes or do any additional configuration
   before completing the installation.

     * Add User - Described in Section 2.8.5, "Add Users".

     * Root Password - Described in Section 2.8.1, "Setting the root
       Password".

     * Hostname - Described in Section 2.5.2, "Setting the Hostname".

     * Network - Described in Section 2.9.1, "Configuring Network
       Interfaces".

     * Services - Described in Section 2.8.3, "Enabling Services".

     * System Hardening - Described in Section 2.8.4, "Enabling Hardening
       Security Options".

     * Time Zone - Described in Section 2.8.2, "Setting the Time Zone".

     * Handbook - Download and install the FreeBSD Handbook.

   After any final configuration is complete, select Exit.

   Figure 2.47. Manual Configuration
   Manual Configuration

   bsdinstall will prompt if there are any additional configuration that
   needs to be done before rebooting into the new system. Select [ Yes ] to
   exit to a shell within the new system or [ No ] to proceed to the last
   step of the installation.

   Figure 2.48. Complete the Installation
   Complete the Installation

   If further configuration or special setup is needed, select [ Live CD ] to
   boot the install media into Live CD mode.

   If the installation is complete, select [ Reboot ] to reboot the computer
   and start the new FreeBSD system. Do not forget to remove the FreeBSD
   install media or the computer may boot from it again.

   As FreeBSD boots, informational messages are displayed. After the system
   finishes booting, a login prompt is displayed. At the login: prompt, enter
   the username added during the installation. Avoid logging in as root.
   Refer to Section 3.3.1.3, "The Superuser Account" for instructions on how
   to become the superuser when administrative access is needed.

   The messages that appeared during boot can be reviewed by pressing
   Scroll-Lock to turn on the scroll-back buffer. The PgUp, PgDn, and arrow
   keys can be used to scroll back through the messages. When finished, press
   Scroll-Lock again to unlock the display and return to the console. To
   review these messages once the system has been up for some time, type less
   /var/run/dmesg.boot from a command prompt. Press q to return to the
   command line after viewing.

   If sshd was enabled in Figure 2.41, "Selecting Additional Services to
   Enable", the first boot may be a bit slower as the system will generate
   the RSA and DSA keys. Subsequent boots will be faster. The fingerprints of
   the keys will be displayed, as seen in this example:

 Generating public/private rsa1 key pair.
 Your identification has been saved in /etc/ssh/ssh_host_key.
 Your public key has been saved in /etc/ssh/ssh_host_key.pub.
 The key fingerprint is:
 10:a0:f5:af:93:ae:a3:1a:b2:bb:3c:35:d9:5a:b3:f3 root@machine3.example.com
 The key's randomart image is:
 +--[RSA1 1024]----+
 |    o..          |
 |   o . .         |
 |  .   o          |
 |       o         |
 |    o   S        |
 |   + + o         |
 |o . + *          |
 |o+ ..+ .         |
 |==o..o+E         |
 +-----------------+
 Generating public/private dsa key pair.
 Your identification has been saved in /etc/ssh/ssh_host_dsa_key.
 Your public key has been saved in /etc/ssh/ssh_host_dsa_key.pub.
 The key fingerprint is:
 7e:1c:ce:dc:8a:3a:18:13:5b:34:b5:cf:d9:d1:47:b2 root@machine3.example.com
 The key's randomart image is:
 +--[ DSA 1024]----+
 |       ..     . .|
 |      o  .   . + |
 |     . ..   . E .|
 |    . .  o o . . |
 |     +  S = .    |
 |    +  . = o     |
 |     +  . * .    |
 |    . .  o .     |
 |      .o. .      |
 +-----------------+
 Starting sshd.

   Refer to Section 14.8, "OpenSSH" for more information about fingerprints
   and SSH.

   FreeBSD does not install a graphical environment by default. Refer to
   Chapter 5, The X Window System for more information about installing and
   configuring a graphical window manager.

   Proper shutdown of a FreeBSD computer helps protect data and hardware from
   damage. Do not turn off the power before the system has been properly shut
   down! If the user is a member of the wheel group, become the superuser by
   typing su at the command line and entering the root password. Then, type
   shutdown -p now and the system will shut down cleanly, and if the hardware
   supports it, turn itself off.

2.9. Network Interfaces

  2.9.1. Configuring Network Interfaces

   Next, a list of the network interfaces found on the computer is shown.
   Select the interface to configure.

   Figure 2.49. Choose a Network Interface
   Choose a Network Interface

   If an Ethernet interface is selected, the installer will skip ahead to the
   menu shown in Figure 2.53, "Choose IPv4 Networking". If a wireless network
   interface is chosen, the system will instead scan for wireless access
   points:

   Figure 2.50. Scanning for Wireless Access Points
   Scanning for Wireless Access Points

   Wireless networks are identified by a Service Set Identifier (SSID), a
   short, unique name given to each network. SSIDs found during the scan are
   listed, followed by a description of the encryption types available for
   that network. If the desired SSID does not appear in the list, select
   [ Rescan ] to scan again. If the desired network still does not appear,
   check for problems with antenna connections or try moving the computer
   closer to the access point. Rescan after each change is made.

   Figure 2.51. Choosing a Wireless Network
   Choosing a Wireless Network

   Next, enter the encryption information for connecting to the selected
   wireless network. WPA2 encryption is strongly recommended as older
   encryption types, like WEP, offer little security. If the network uses
   WPA2, input the password, also known as the Pre-Shared Key (PSK). For
   security reasons, the characters typed into the input box are displayed as
   asterisks.

   Figure 2.52. WPA2 Setup
   WPA2 Setup

   Next, choose whether or not an IPv4 address should be configured on the
   Ethernet or wireless interface:

   Figure 2.53. Choose IPv4 Networking
   Choose IPv4 Networking

   There are two methods of IPv4 configuration. DHCP will automatically
   configure the network interface correctly and should be used if the
   network provides a DHCP server. Otherwise, the addressing information
   needs to be input manually as a static configuration.

  Note:

   Do not enter random network information as it will not work. If a DHCP
   server is not available, obtain the information listed in Required Network
   Information from the network administrator or Internet service provider.

   If a DHCP server is available, select [ Yes ] in the next menu to
   automatically configure the network interface. The installer will appear
   to pause for a minute or so as it finds the DHCP server and obtains the
   addressing information for the system.

   Figure 2.54. Choose IPv4 DHCP Configuration
   Choose IPv4 DHCP Configuration

   If a DHCP server is not available, select [ No ] and input the following
   addressing information in this menu:

   Figure 2.55. IPv4 Static Configuration
   IPv4 Static Configuration
     * IP Address - The IPv4 address assigned to this computer. The address
       must be unique and not already in use by another piece of equipment on
       the local network.

     * Subnet Mask - The subnet mask for the network.

     * Default Router - The IP address of the network's default gateway.

   The next screen will ask if the interface should be configured for IPv6.
   If IPv6 is available and desired, choose [ Yes ] to select it.

   Figure 2.56. Choose IPv6 Networking
   Choose IPv6 Networking

   IPv6 also has two methods of configuration. StateLess Address
   AutoConfiguration (SLAAC) will automatically request the correct
   configuration information from a local router. Refer to rfc4862 for more
   information. Static configuration requires manual entry of network
   information.

   If an IPv6 router is available, select [ Yes ] in the next menu to
   automatically configure the network interface. The installer will appear
   to pause for a minute or so as it finds the router and obtains the
   addressing information for the system.

   Figure 2.57. Choose IPv6 SLAAC Configuration
   Choose IPv6 SLAAC Configuration

   If an IPv6 router is not available, select [ No ] and input the following
   addressing information in this menu:

   Figure 2.58. IPv6 Static Configuration
   IPv6 Static Configuration
     * IPv6 Address - The IPv6 address assigned to this computer. The address
       must be unique and not already in use by another piece of equipment on
       the local network.

     * Default Router - The IPv6 address of the network's default gateway.

   The last network configuration menu is used to configure the Domain Name
   System (DNS) resolver, which converts hostnames to and from network
   addresses. If DHCP or SLAAC was used to autoconfigure the network
   interface, the Resolver Configuration values may already be filled in.
   Otherwise, enter the local network's domain name in the Search field. DNS
   #1 and DNS #2 are the IPv4 and/or IPv6 addresses of the DNS servers. At
   least one DNS server is required.

   Figure 2.59. DNS Configuration
   DNS Configuration

   Once the interface is configured, select a mirror site that is located in
   the same region of the world as the computer on which FreeBSD is being
   installed. Files can be retrieved more quickly when the mirror is close to
   the target computer, reducing installation time.

   Figure 2.60. Choosing a Mirror
   Choosing a Mirror

2.10. Troubleshooting

   This section covers basic installation troubleshooting, such as common
   problems people have reported.

   Check the Hardware Notes (https://www.freebsd.org/releases/index.html)
   document for the version of FreeBSD to make sure the hardware is
   supported. If the hardware is supported and lock-ups or other problems
   occur, build a custom kernel using the instructions in Chapter 8,
   Configuring the FreeBSD Kernel to add support for devices which are not
   present in the GENERIC kernel. The default kernel assumes that most
   hardware devices are in their factory default configuration in terms of
   IRQs, I/O addresses, and DMA channels. If the hardware has been
   reconfigured, a custom kernel configuration file can tell FreeBSD where to
   find things.

  Note:

   Some installation problems can be avoided or alleviated by updating the
   firmware on various hardware components, most notably the motherboard.
   Motherboard firmware is usually referred to as the BIOS. Most motherboard
   and computer manufacturers have a website for upgrades and upgrade
   information.

   Manufacturers generally advise against upgrading the motherboard BIOS
   unless there is a good reason for doing so, like a critical update. The
   upgrade process can go wrong, leaving the BIOS incomplete and the computer
   inoperative.

   If the system hangs while probing hardware during boot, or it behaves
   strangely during install, ACPI may be the culprit. FreeBSD makes extensive
   use of the system ACPI service on the i386 and amd64 platforms to aid in
   system configuration if it is detected during boot. Unfortunately, some
   bugs still exist in both the ACPI driver and within system motherboards
   and BIOS firmware. ACPI can be disabled by setting the
   hint.acpi.0.disabled hint in the third stage boot loader:

 set hint.acpi.0.disabled="1"

   This is reset each time the system is booted, so it is necessary to add
   hint.acpi.0.disabled="1" to the file /boot/loader.conf. More information
   about the boot loader can be found in Section 13.1, "Synopsis".

2.11. Using the Live CD

   The welcome menu of bsdinstall, shown in Figure 2.3, "Welcome Menu",
   provides a [ Live CD ] option. This is useful for those who are still
   wondering whether FreeBSD is the right operating system for them and want
   to test some of the features before installing.

   The following points should be noted before using the [ Live CD ]:

     * To gain access to the system, authentication is required. The username
       is root and the password is blank.

     * As the system runs directly from the installation media, performance
       will be significantly slower than that of a system installed on a hard
       disk.

     * This option only provides a command prompt and not a graphical
       interface.

Chapter 3. FreeBSD Basics

   Table of Contents

   3.1. Synopsis

   3.2. Virtual Consoles and Terminals

   3.3. Users and Basic Account Management

   3.4. Permissions

   3.5. Directory Structure

   3.6. Disk Organization

   3.7. Mounting and Unmounting File Systems

   3.8. Processes and Daemons

   3.9. Shells

   3.10. Text Editors

   3.11. Devices and Device Nodes

   3.12. Manual Pages

3.1. Synopsis

   This chapter covers the basic commands and functionality of the FreeBSD
   operating system. Much of this material is relevant for any UNIX(R)-like
   operating system. New FreeBSD users are encouraged to read through this
   chapter carefully.

   After reading this chapter, you will know:

     * How to use and configure virtual consoles.

     * How to create and manage users and groups on FreeBSD.

     * How UNIX(R) file permissions and FreeBSD file flags work.

     * The default FreeBSD file system layout.

     * The FreeBSD disk organization.

     * How to mount and unmount file systems.

     * What processes, daemons, and signals are.

     * What a shell is, and how to change the default login environment.

     * How to use basic text editors.

     * What devices and device nodes are.

     * How to read manual pages for more information.

3.2. Virtual Consoles and Terminals

   Unless FreeBSD has been configured to automatically start a graphical
   environment during startup, the system will boot into a command line login
   prompt, as seen in this example:

 FreeBSD/amd64 (pc3.example.org) (ttyv0)

 login:

   The first line contains some information about the system. The amd64
   indicates that the system in this example is running a 64-bit version of
   FreeBSD. The hostname is pc3.example.org, and ttyv0 indicates that this is
   the "system console". The second line is the login prompt.

   Since FreeBSD is a multiuser system, it needs some way to distinguish
   between different users. This is accomplished by requiring every user to
   log into the system before gaining access to the programs on the system.
   Every user has a unique name "username" and a personal "password".

   To log into the system console, type the username that was configured
   during system installation, as described in Section 2.8.5, "Add Users",
   and press Enter. Then enter the password associated with the username and
   press Enter. The password is not echoed for security reasons.

   Once the correct password is input, the message of the day (MOTD) will be
   displayed followed by a command prompt. Depending upon the shell that was
   selected when the user was created, this prompt will be a #, $, or %
   character. The prompt indicates that the user is now logged into the
   FreeBSD system console and ready to try the available commands.

  3.2.1. Virtual Consoles

   While the system console can be used to interact with the system, a user
   working from the command line at the keyboard of a FreeBSD system will
   typically instead log into a virtual console. This is because system
   messages are configured by default to display on the system console. These
   messages will appear over the command or file that the user is working on,
   making it difficult to concentrate on the work at hand.

   By default, FreeBSD is configured to provide several virtual consoles for
   inputting commands. Each virtual console has its own login prompt and
   shell and it is easy to switch between virtual consoles. This essentially
   provides the command line equivalent of having several windows open at the
   same time in a graphical environment.

   The key combinations Alt+F1 through Alt+F8 have been reserved by FreeBSD
   for switching between virtual consoles. Use Alt+F1 to switch to the system
   console (ttyv0), Alt+F2 to access the first virtual console (ttyv1),
   Alt+F3 to access the second virtual console (ttyv2), and so on. When using
   Xorg as a graphical console, the combination becomes Ctrl+Alt+F1 to return
   to a text-based virtual console.

   When switching from one console to the next, FreeBSD manages the screen
   output. The result is an illusion of having multiple virtual screens and
   keyboards that can be used to type commands for FreeBSD to run. The
   programs that are launched in one virtual console do not stop running when
   the user switches to a different virtual console.

   Refer to kbdcontrol(1), vidcontrol(1), atkbd(4), syscons(4), and vt(4) for
   a more technical description of the FreeBSD console and its keyboard
   drivers.

   In FreeBSD, the number of available virtual consoles is configured in this
   section of /etc/ttys:

 # name    getty                         type  status comments
 #
 ttyv0   "/usr/libexec/getty Pc"         xterm   on  secure
 # Virtual terminals
 ttyv1   "/usr/libexec/getty Pc"         xterm   on  secure
 ttyv2   "/usr/libexec/getty Pc"         xterm   on  secure
 ttyv3   "/usr/libexec/getty Pc"         xterm   on  secure
 ttyv4   "/usr/libexec/getty Pc"         xterm   on  secure
 ttyv5   "/usr/libexec/getty Pc"         xterm   on  secure
 ttyv6   "/usr/libexec/getty Pc"         xterm   on  secure
 ttyv7   "/usr/libexec/getty Pc"         xterm   on  secure
 ttyv8   "/usr/X11R6/bin/xdm -nodaemon"  xterm   off secure

   To disable a virtual console, put a comment symbol (#) at the beginning of
   the line representing that virtual console. For example, to reduce the
   number of available virtual consoles from eight to four, put a # in front
   of the last four lines representing virtual consoles ttyv5 through ttyv8.
   Do not comment out the line for the system console ttyv0. Note that the
   last virtual console (ttyv8) is used to access the graphical environment
   if Xorg has been installed and configured as described in Chapter 5, The X
   Window System.

   For a detailed description of every column in this file and the available
   options for the virtual consoles, refer to ttys(5).

  3.2.2. Single User Mode

   The FreeBSD boot menu provides an option labelled as "Boot Single User".
   If this option is selected, the system will boot into a special mode known
   as "single user mode". This mode is typically used to repair a system that
   will not boot or to reset the root password when it is not known. While in
   single user mode, networking and other virtual consoles are not available.
   However, full root access to the system is available, and by default, the
   root password is not needed. For these reasons, physical access to the
   keyboard is needed to boot into this mode and determining who has physical
   access to the keyboard is something to consider when securing a FreeBSD
   system.

   The settings which control single user mode are found in this section of
   /etc/ttys:

 # name  getty                           type  status  comments
 #
 # If console is marked "insecure", then init will ask for the root password
 # when going to single-user mode.
 console none                            unknown  off  secure

   By default, the status is set to secure. This assumes that who has
   physical access to the keyboard is either not important or it is
   controlled by a physical security policy. If this setting is changed to
   insecure, the assumption is that the environment itself is insecure
   because anyone can access the keyboard. When this line is changed to
   insecure, FreeBSD will prompt for the root password when a user selects to
   boot into single user mode.

  Note:

   Be careful when changing this setting to insecure! If the root password is
   forgotten, booting into single user mode is still possible, but may be
   difficult for someone who is not familiar with the FreeBSD booting
   process.

  3.2.3. Changing Console Video Modes

   The FreeBSD console default video mode may be adjusted to 1024x768,
   1280x1024, or any other size supported by the graphics chip and monitor.
   To use a different video mode load the VESA module:

 # kldload vesa

   To determine which video modes are supported by the hardware, use
   vidcontrol(1). To get a list of supported video modes issue the following:

 # vidcontrol -i mode

   The output of this command lists the video modes that are supported by the
   hardware. To select a new video mode, specify the mode using vidcontrol(1)
   as the root user:

 # vidcontrol MODE_279

   If the new video mode is acceptable, it can be permanently set on boot by
   adding it to /etc/rc.conf:

 allscreens_flags="MODE_279"

3.3. Users and Basic Account Management

   FreeBSD allows multiple users to use the computer at the same time. While
   only one user can sit in front of the screen and use the keyboard at any
   one time, any number of users can log in to the system through the
   network. To use the system, each user should have their own user account.

   This chapter describes:

     * The different types of user accounts on a FreeBSD system.

     * How to add, remove, and modify user accounts.

     * How to set limits to control the resources that users and groups are
       allowed to access.

     * How to create groups and add users as members of a group.

  3.3.1. Account Types

   Since all access to the FreeBSD system is achieved using accounts and all
   processes are run by users, user and account management is important.

   There are three main types of accounts: system accounts, user accounts,
   and the superuser account.

    3.3.1.1. System Accounts

   System accounts are used to run services such as DNS, mail, and web
   servers. The reason for this is security; if all services ran as the
   superuser, they could act without restriction.

   Examples of system accounts are daemon, operator, bind, news, and www.

  Warning:

   Care must be taken when using the operator group, as unintended
   superuser-like access privileges may be granted, including but not limited
   to shutdown, reboot, and access to all items in /dev in the group.

   nobody is the generic unprivileged system account. However, the more
   services that use nobody, the more files and processes that user will
   become associated with, and hence the more privileged that user becomes.

    3.3.1.2. User Accounts

   User accounts are assigned to real people and are used to log in and use
   the system. Every person accessing the system should have a unique user
   account. This allows the administrator to find out who is doing what and
   prevents users from clobbering the settings of other users.

   Each user can set up their own environment to accommodate their use of the
   system, by configuring their default shell, editor, key bindings, and
   language settings.

   Every user account on a FreeBSD system has certain information associated
   with it:

   User name

           The user name is typed at the login: prompt. Each user must have a
           unique user name. There are a number of rules for creating valid
           user names which are documented in passwd(5). It is recommended to
           use user names that consist of eight or fewer, all lower case
           characters in order to maintain backwards compatibility with
           applications.

   Password

           Each account has an associated password.

   User ID (UID)

           The User ID (UID) is a number used to uniquely identify the user
           to the FreeBSD system. Commands that allow a user name to be
           specified will first convert it to the UID. It is recommended to
           use a UID less than 65535, since higher values may cause
           compatibility issues with some software.

   Group ID (GID)

           The Group ID (GID) is a number used to uniquely identify the
           primary group that the user belongs to. Groups are a mechanism for
           controlling access to resources based on a user's GID rather than
           their UID. This can significantly reduce the size of some
           configuration files and allows users to be members of more than
           one group. It is recommended to use a GID of 65535 or lower as
           higher GIDs may break some software.

   Login class

           Login classes are an extension to the group mechanism that provide
           additional flexibility when tailoring the system to different
           users. Login classes are discussed further in Section 14.13.1,
           "Configuring Login Classes".

   Password change time

           By default, passwords do not expire. However, password expiration
           can be enabled on a per-user basis, forcing some or all users to
           change their passwords after a certain amount of time has elapsed.

   Account expiration time

           By default, FreeBSD does not expire accounts. When creating
           accounts that need a limited lifespan, such as student accounts in
           a school, specify the account expiry date using pw(8). After the
           expiry time has elapsed, the account cannot be used to log in to
           the system, although the account's directories and files will
           remain.

   User's full name

           The user name uniquely identifies the account to FreeBSD, but does
           not necessarily reflect the user's real name. Similar to a
           comment, this information can contain spaces, uppercase
           characters, and be more than 8 characters long.

   Home directory

           The home directory is the full path to a directory on the system.
           This is the user's starting directory when the user logs in. A
           common convention is to put all user home directories under
           /home/username or /usr/home/username. Each user stores their
           personal files and subdirectories in their own home directory.

   User shell

           The shell provides the user's default environment for interacting
           with the system. There are many different kinds of shells and
           experienced users will have their own preferences, which can be
           reflected in their account settings.

    3.3.1.3. The Superuser Account

   The superuser account, usually called root, is used to manage the system
   with no limitations on privileges. For this reason, it should not be used
   for day-to-day tasks like sending and receiving mail, general exploration
   of the system, or programming.

   The superuser, unlike other user accounts, can operate without limits, and
   misuse of the superuser account may result in spectacular disasters. User
   accounts are unable to destroy the operating system by mistake, so it is
   recommended to login as a user account and to only become the superuser
   when a command requires extra privilege.

   Always double and triple-check any commands issued as the superuser, since
   an extra space or missing character can mean irreparable data loss.

   There are several ways to gain superuser privilege. While one can log in
   as root, this is highly discouraged.

   Instead, use su(1) to become the superuser. If - is specified when running
   this command, the user will also inherit the root user's environment. The
   user running this command must be in the wheel group or else the command
   will fail. The user must also know the password for the root user account.

   In this example, the user only becomes superuser in order to run make
   install as this step requires superuser privilege. Once the command
   completes, the user types exit to leave the superuser account and return
   to the privilege of their user account.

   Example 3.1. Install a Program As the Superuser

 % configure
 % make
 % su -
 Password:
 # make install
 # exit
 %

   The built-in su(1) framework works well for single systems or small
   networks with just one system administrator. An alternative is to install
   the security/sudo package or port. This software provides activity logging
   and allows the administrator to configure which users can run which
   commands as the superuser.

  3.3.2. Managing Accounts

   FreeBSD provides a variety of different commands to manage user accounts.
   The most common commands are summarized in Table 3.1, "Utilities for
   Managing User Accounts", followed by some examples of their usage. See the
   manual page for each utility for more details and usage examples.

   Table 3.1. Utilities for Managing User Accounts

    Command                               Summary                             
   adduser(8) The recommended command-line application for adding new users.  
   rmuser(8)  The recommended command-line application for removing users.    
   chpass(1)  A flexible tool for changing user database information.         
   passwd(1)  The command-line tool to change user passwords.                 
   pw(8)      A powerful and flexible tool for modifying all aspects of user  
              accounts.                                                       

    3.3.2.1. adduser

   The recommended program for adding new users is adduser(8). When a new
   user is added, this program automatically updates /etc/passwd and
   /etc/group. It also creates a home directory for the new user, copies in
   the default configuration files from /usr/share/skel, and can optionally
   mail the new user a welcome message. This utility must be run as the
   superuser.

   The adduser(8) utility is interactive and walks through the steps for
   creating a new user account. As seen in Example 3.2, "Adding a User on
   FreeBSD", either input the required information or press Return to accept
   the default value shown in square brackets. In this example, the user has
   been invited into the wheel group, allowing them to become the superuser
   with su(1). When finished, the utility will prompt to either create
   another user or to exit.

   Example 3.2. Adding a User on FreeBSD

 # adduser
 Username: jru
 Full name: J. Random User
 Uid (Leave empty for default):
 Login group [jru]:
 Login group is jru. Invite jru into other groups? []: wheel
 Login class [default]:
 Shell (sh csh tcsh zsh nologin) [sh]: zsh
 Home directory [/home/jru]:
 Home directory permissions (Leave empty for default):
 Use password-based authentication? [yes]:
 Use an empty password? (yes/no) [no]:
 Use a random password? (yes/no) [no]:
 Enter password:
 Enter password again:
 Lock out the account after creation? [no]:
 Username   : jru
 Password   : ****
 Full Name  : J. Random User
 Uid        : 1001
 Class      :
 Groups     : jru wheel
 Home       : /home/jru
 Shell      : /usr/local/bin/zsh
 Locked     : no
 OK? (yes/no): yes
 adduser: INFO: Successfully added (jru) to the user database.
 Add another user? (yes/no): no
 Goodbye!
 #

  Note:

   Since the password is not echoed when typed, be careful to not mistype the
   password when creating the user account.

    3.3.2.2. rmuser

   To completely remove a user from the system, run rmuser(8) as the
   superuser. This command performs the following steps:

    1. Removes the user's crontab(1) entry, if one exists.

    2. Removes any at(1) jobs belonging to the user.

    3. Kills all processes owned by the user.

    4. Removes the user from the system's local password file.

    5. Optionally removes the user's home directory, if it is owned by the
       user.

    6. Removes the incoming mail files belonging to the user from /var/mail.

    7. Removes all files owned by the user from temporary file storage areas
       such as /tmp.

    8. Finally, removes the username from all groups to which it belongs in
       /etc/group. If a group becomes empty and the group name is the same as
       the username, the group is removed. This complements the per-user
       unique groups created by adduser(8).

   rmuser(8) cannot be used to remove superuser accounts since that is almost
   always an indication of massive destruction.

   By default, an interactive mode is used, as shown in the following
   example.

   Example 3.3. rmuser Interactive Account Removal

 # rmuser jru
 Matching password entry:
 jru:*:1001:1001::0:0:J. Random User:/home/jru:/usr/local/bin/zsh
 Is this the entry you wish to remove? y
 Remove user's home directory (/home/jru)? y
 Removing user (jru): mailspool home passwd.
 #

    3.3.2.3. chpass

   Any user can use chpass(1) to change their default shell and personal
   information associated with their user account. The superuser can use this
   utility to change additional account information for any user.

   When passed no options, aside from an optional username, chpass(1)
   displays an editor containing user information. When the user exits from
   the editor, the user database is updated with the new information.

  Note:

   This utility will prompt for the user's password when exiting the editor,
   unless the utility is run as the superuser.

   In Example 3.4, "Using chpass as Superuser", the superuser has typed
   chpass jru and is now viewing the fields that can be changed for this
   user. If jru runs this command instead, only the last six fields will be
   displayed and available for editing. This is shown in Example 3.5, "Using
   chpass as Regular User".

   Example 3.4. Using chpass as Superuser

 #Changing user database information for jru.
 Login: jru
 Password: *
 Uid [#]: 1001
 Gid [# or name]: 1001
 Change [month day year]:
 Expire [month day year]:
 Class:
 Home directory: /home/jru
 Shell: /usr/local/bin/zsh
 Full Name: J. Random User
 Office Location:
 Office Phone:
 Home Phone:
 Other information:

   Example 3.5. Using chpass as Regular User

 #Changing user database information for jru.
 Shell: /usr/local/bin/zsh
 Full Name: J. Random User
 Office Location:
 Office Phone:
 Home Phone:
 Other information:

  Note:

   The commands chfn(1) and chsh(1) are links to chpass(1), as are
   ypchpass(1), ypchfn(1), and ypchsh(1). Since NIS support is automatic,
   specifying the yp before the command is not necessary. How to configure
   NIS is covered in Chapter 30, Network Servers.

    3.3.2.4. passwd

   Any user can easily change their password using passwd(1). To prevent
   accidental or unauthorized changes, this command will prompt for the
   user's original password before a new password can be set:

   Example 3.6. Changing Your Password

 % passwd
 Changing local password for jru.
 Old password:
 New password:
 Retype new password:
 passwd: updating the database...
 passwd: done

   The superuser can change any user's password by specifying the username
   when running passwd(1). When this utility is run as the superuser, it will
   not prompt for the user's current password. This allows the password to be
   changed when a user cannot remember the original password.

   Example 3.7. Changing Another User's Password as the Superuser

 # passwd jru
 Changing local password for jru.
 New password:
 Retype new password:
 passwd: updating the database...
 passwd: done

  Note:

   As with chpass(1), yppasswd(1) is a link to passwd(1), so NIS works with
   either command.

    3.3.2.5. pw

   The pw(8) utility can create, remove, modify, and display users and
   groups. It functions as a front end to the system user and group files.
   pw(8) has a very powerful set of command line options that make it
   suitable for use in shell scripts, but new users may find it more
   complicated than the other commands presented in this section.

  3.3.3. Managing Groups

   A group is a list of users. A group is identified by its group name and
   GID. In FreeBSD, the kernel uses the UID of a process, and the list of
   groups it belongs to, to determine what the process is allowed to do. Most
   of the time, the GID of a user or process usually means the first group in
   the list.

   The group name to GID mapping is listed in /etc/group. This is a plain
   text file with four colon-delimited fields. The first field is the group
   name, the second is the encrypted password, the third the GID, and the
   fourth the comma-delimited list of members. For a more complete
   description of the syntax, refer to group(5).

   The superuser can modify /etc/group using a text editor. Alternatively,
   pw(8) can be used to add and edit groups. For example, to add a group
   called teamtwo and then confirm that it exists:

   Example 3.8. Adding a Group Using pw(8)

 # pw groupadd teamtwo
 # pw groupshow teamtwo
 teamtwo:*:1100:

   In this example, 1100 is the GID of teamtwo. Right now, teamtwo has no
   members. This command will add jru as a member of teamtwo.

   Example 3.9. Adding User Accounts to a New Group Using pw(8)

 # pw groupmod teamtwo -M jru
 # pw groupshow teamtwo
 teamtwo:*:1100:jru

   The argument to -M is a comma-delimited list of users to be added to a new
   (empty) group or to replace the members of an existing group. To the user,
   this group membership is different from (and in addition to) the user's
   primary group listed in the password file. This means that the user will
   not show up as a member when using groupshow with pw(8), but will show up
   when the information is queried via id(1) or a similar tool. When pw(8) is
   used to add a user to a group, it only manipulates /etc/group and does not
   attempt to read additional data from /etc/passwd.

   Example 3.10. Adding a New Member to a Group Using pw(8)

 # pw groupmod teamtwo -m db
 # pw groupshow teamtwo
 teamtwo:*:1100:jru,db

   In this example, the argument to -m is a comma-delimited list of users who
   are to be added to the group. Unlike the previous example, these users are
   appended to the group and do not replace existing users in the group.

   Example 3.11. Using id(1) to Determine Group Membership

 % id jru
 uid=1001(jru) gid=1001(jru) groups=1001(jru), 1100(teamtwo)

   In this example, jru is a member of the groups jru and teamtwo.

   For more information about this command and the format of /etc/group,
   refer to pw(8) and group(5).

3.4. Permissions

   In FreeBSD, every file and directory has an associated set of permissions
   and several utilities are available for viewing and modifying these
   permissions. Understanding how permissions work is necessary to make sure
   that users are able to access the files that they need and are unable to
   improperly access the files used by the operating system or owned by other
   users.

   This section discusses the traditional UNIX(R) permissions used in
   FreeBSD. For finer grained file system access control, refer to
   Section 14.9, "Access Control Lists".

   In UNIX(R), basic permissions are assigned using three types of access:
   read, write, and execute. These access types are used to determine file
   access to the file's owner, group, and others (everyone else). The read,
   write, and execute permissions can be represented as the letters r, w, and
   x. They can also be represented as binary numbers as each permission is
   either on or off (0). When represented as a number, the order is always
   read as rwx, where r has an on value of 4, w has an on value of 2 and x
   has an on value of 1.

   Table 4.1 summarizes the possible numeric and alphabetic possibilities.
   When reading the "Directory Listing" column, a - is used to represent a
   permission that is set to off.

   Table 3.2. UNIX(R) Permissions

      Value                  Permission                 Directory Listing     
   0            No read, no write, no execute        ---                      
   1            No read, no write, execute           --x                      
   2            No read, write, no execute           -w-                      
   3            No read, write, execute              -wx                      
   4            Read, no write, no execute           r--                      
   5            Read, no write, execute              r-x                      
   6            Read, write, no execute              rw-                      
   7            Read, write, execute                 rwx                      

   Use the -l argument to ls(1) to view a long directory listing that
   includes a column of information about a file's permissions for the owner,
   group, and everyone else. For example, an ls -l in an arbitrary directory
   may show:

 % ls -l
 total 530
 -rw-r--r--  1 root  wheel     512 Sep  5 12:31 myfile
 -rw-r--r--  1 root  wheel     512 Sep  5 12:31 otherfile
 -rw-r--r--  1 root  wheel    7680 Sep  5 12:31 email.txt

   The first (leftmost) character in the first column indicates whether this
   file is a regular file, a directory, a special character device, a socket,
   or any other special pseudo-file device. In this example, the - indicates
   a regular file. The next three characters, rw- in this example, give the
   permissions for the owner of the file. The next three characters, r--,
   give the permissions for the group that the file belongs to. The final
   three characters, r--, give the permissions for the rest of the world. A
   dash means that the permission is turned off. In this example, the
   permissions are set so the owner can read and write to the file, the group
   can read the file, and the rest of the world can only read the file.
   According to the table above, the permissions for this file would be 644,
   where each digit represents the three parts of the file's permission.

   How does the system control permissions on devices? FreeBSD treats most
   hardware devices as a file that programs can open, read, and write data
   to. These special device files are stored in /dev/.

   Directories are also treated as files. They have read, write, and execute
   permissions. The executable bit for a directory has a slightly different
   meaning than that of files. When a directory is marked executable, it
   means it is possible to change into that directory using cd(1). This also
   means that it is possible to access the files within that directory,
   subject to the permissions on the files themselves.

   In order to perform a directory listing, the read permission must be set
   on the directory. In order to delete a file that one knows the name of, it
   is necessary to have write and execute permissions to the directory
   containing the file.

   There are more permission bits, but they are primarily used in special
   circumstances such as setuid binaries and sticky directories. For more
   information on file permissions and how to set them, refer to chmod(1).

  3.4.1. Symbolic Permissions

   Contributed by Tom Rhodes.

   Symbolic permissions use characters instead of octal values to assign
   permissions to files or directories. Symbolic permissions use the syntax
   of (who) (action) (permissions), where the following values are available:

           Option             Letter                  Represents              
   (who)                  u               User                                
   (who)                  g               Group owner                         
   (who)                  o               Other                               
   (who)                  a               All ("world")                       
   (action)               +               Adding permissions                  
   (action)               -               Removing permissions                
   (action)               =               Explicitly set permissions          
   (permissions)          r               Read                                
   (permissions)          w               Write                               
   (permissions)          x               Execute                             
   (permissions)          t               Sticky bit                          
   (permissions)          s               Set UID or GID                      

   These values are used with chmod(1), but with letters instead of numbers.
   For example, the following command would block other users from accessing
   FILE:

 % chmod go= FILE

   A comma separated list can be provided when more than one set of changes
   to a file must be made. For example, the following command removes the
   group and "world" write permission on FILE, and adds the execute
   permissions for everyone:

 % chmod go-w,a+x FILE

  3.4.2. FreeBSD File Flags

   Contributed by Tom Rhodes.

   In addition to file permissions, FreeBSD supports the use of "file flags".
   These flags add an additional level of security and control over files,
   but not directories. With file flags, even root can be prevented from
   removing or altering files.

   File flags are modified using chflags(1). For example, to enable the
   system undeletable flag on the file file1, issue the following command:

 # chflags sunlink file1

   To disable the system undeletable flag, put a "no" in front of the
   sunlink:

 # chflags nosunlink file1

   To view the flags of a file, use -lo with ls(1):

 # ls -lo file1

 -rw-r--r--  1 trhodes  trhodes  sunlnk 0 Mar  1 05:54 file1

   Several file flags may only be added or removed by the root user. In other
   cases, the file owner may set its file flags. Refer to chflags(1) and
   chflags(2) for more information.

  3.4.3. The setuid, setgid, and sticky Permissions

   Contributed by Tom Rhodes.

   Other than the permissions already discussed, there are three other
   specific settings that all administrators should know about. They are the
   setuid, setgid, and sticky permissions.

   These settings are important for some UNIX(R) operations as they provide
   functionality not normally granted to normal users. To understand them,
   the difference between the real user ID and effective user ID must be
   noted.

   The real user ID is the UID who owns or starts the process. The effective
   UID is the user ID the process runs as. As an example, passwd(1) runs with
   the real user ID when a user changes their password. However, in order to
   update the password database, the command runs as the effective ID of the
   root user. This allows users to change their passwords without seeing a
   Permission Denied error.

   The setuid permission may be set by prefixing a permission set with the
   number four (4) as shown in the following example:

 # chmod 4755 suidexample.sh

   The permissions on suidexample.sh now look like the following:

 -rwsr-xr-x   1 trhodes  trhodes    63 Aug 29 06:36 suidexample.sh

   Note that a s is now part of the permission set designated for the file
   owner, replacing the executable bit. This allows utilities which need
   elevated permissions, such as passwd(1).

  Note:

   The nosuid mount(8) option will cause such binaries to silently fail
   without alerting the user. That option is not completely reliable as a
   nosuid wrapper may be able to circumvent it.

   To view this in real time, open two terminals. On one, type passwd as a
   normal user. While it waits for a new password, check the process table
   and look at the user information for passwd(1):

   In terminal A:

 Changing local password for trhodes
 Old Password:

   In terminal B:

 # ps aux | grep passwd

 trhodes  5232  0.0  0.2  3420  1608   0  R+    2:10AM   0:00.00 grep passwd
 root     5211  0.0  0.2  3620  1724   2  I+    2:09AM   0:00.01 passwd

   Although passwd(1) is run as a normal user, it is using the effective UID
   of root.

   The setgid permission performs the same function as the setuid permission;
   except that it alters the group settings. When an application or utility
   executes with this setting, it will be granted the permissions based on
   the group that owns the file, not the user who started the process.

   To set the setgid permission on a file, provide chmod(1) with a leading
   two (2):

 # chmod 2755 sgidexample.sh

   In the following listing, notice that the s is now in the field designated
   for the group permission settings:

 -rwxr-sr-x   1 trhodes  trhodes    44 Aug 31 01:49 sgidexample.sh

  Note:

   In these examples, even though the shell script in question is an
   executable file, it will not run with a different EUID or effective user
   ID. This is because shell scripts may not access the setuid(2) system
   calls.

   The setuid and setgid permission bits may lower system security, by
   allowing for elevated permissions. The third special permission, the
   sticky bit, can strengthen the security of a system.

   When the sticky bit is set on a directory, it allows file deletion only by
   the file owner. This is useful to prevent file deletion in public
   directories, such as /tmp, by users who do not own the file. To utilize
   this permission, prefix the permission set with a one (1):

 # chmod 1777 /tmp

   The sticky bit permission will display as a t at the very end of the
   permission set:

 # ls -al / | grep tmp

 drwxrwxrwt  10 root  wheel         512 Aug 31 01:49 tmp

3.5. Directory Structure

   The FreeBSD directory hierarchy is fundamental to obtaining an overall
   understanding of the system. The most important directory is root or, "/".
   This directory is the first one mounted at boot time and it contains the
   base system necessary to prepare the operating system for multi-user
   operation. The root directory also contains mount points for other file
   systems that are mounted during the transition to multi-user operation.

   A mount point is a directory where additional file systems can be grafted
   onto a parent file system (usually the root file system). This is further
   described in Section 3.6, "Disk Organization". Standard mount points
   include /usr/, /var/, /tmp/, /mnt/, and /cdrom/. These directories are
   usually referenced to entries in /etc/fstab. This file is a table of
   various file systems and mount points and is read by the system. Most of
   the file systems in /etc/fstab are mounted automatically at boot time from
   the script rc(8) unless their entry includes noauto. Details can be found
   in Section 3.7.1, "The fstab File".

   A complete description of the file system hierarchy is available in
   hier(7). The following table provides a brief overview of the most common
   directories.

      Directory                           Description                         
   /               Root directory of the file system.                         
   /bin/           User utilities fundamental to both single-user and         
                   multi-user environments.                                   
   /boot/          Programs and configuration files used during operating     
                   system bootstrap.                                          
   /boot/defaults/ Default boot configuration files. Refer to loader.conf(5)  
                   for details.                                               
   /dev/           Device nodes. Refer to intro(4) for details.               
   /etc/           System configuration files and scripts.                    
   /etc/defaults/  Default system configuration files. Refer to rc(8) for     
                   details.                                                   
   /etc/mail/      Configuration files for mail transport agents such as      
                   sendmail(8).                                               
   /etc/periodic/  Scripts that run daily, weekly, and monthly, via cron(8).  
                   Refer to periodic(8) for details.                          
   /etc/ppp/       ppp(8) configuration files.                                
   /mnt/           Empty directory commonly used by system administrators as  
                   a temporary mount point.                                   
   /proc/          Process file system. Refer to procfs(5), mount_procfs(8)   
                   for details.                                               
   /rescue/        Statically linked programs for emergency recovery as       
                   described in rescue(8).                                    
   /root/          Home directory for the root account.                       
   /sbin/          System programs and administration utilities fundamental   
                   to both single-user and multi-user environments.           
   /tmp/           Temporary files which are usually not preserved across a   
                   system reboot. A memory-based file system is often mounted 
                   at /tmp. This can be automated using the tmpmfs-related    
                   variables of rc.conf(5) or with an entry in /etc/fstab;    
                   refer to mdmfs(8) for details.                             
   /usr/           The majority of user utilities and applications.           
   /usr/bin/       Common utilities, programming tools, and applications.     
   /usr/include/   Standard C include files.                                  
   /usr/lib/       Archive libraries.                                         
   /usr/libdata/   Miscellaneous utility data files.                          
   /usr/libexec/   System daemons and system utilities executed by other      
                   programs.                                                  
   /usr/local/     Local executables and libraries. Also used as the default  
                   destination for the FreeBSD ports framework. Within        
                   /usr/local, the general layout sketched out by hier(7) for 
                   /usr should be used. Exceptions are the man directory,     
                   which is directly under /usr/local rather than under       
                   /usr/local/share, and the ports documentation is in        
                   share/doc/port.                                            
   /usr/obj/       Architecture-specific target tree produced by building the 
                   /usr/src tree.                                             
   /usr/ports/     The FreeBSD Ports Collection (optional).                   
   /usr/sbin/      System daemons and system utilities executed by users.     
   /usr/share/     Architecture-independent files.                            
   /usr/src/       BSD and/or local source files.                             
   /var/           Multi-purpose log, temporary, transient, and spool files.  
                   A memory-based file system is sometimes mounted at /var.   
                   This can be automated using the varmfs-related variables   
                   in rc.conf(5) or with an entry in /etc/fstab; refer to     
                   mdmfs(8) for details.                                      
   /var/log/       Miscellaneous system log files.                            
   /var/mail/      User mailbox files.                                        
   /var/spool/     Miscellaneous printer and mail system spooling             
                   directories.                                               
   /var/tmp/       Temporary files which are usually preserved across a       
                   system reboot, unless /var is a memory-based file system.  
   /var/yp/        NIS maps.                                                  

3.6. Disk Organization

   The smallest unit of organization that FreeBSD uses to find files is the
   filename. Filenames are case-sensitive, which means that readme.txt and
   README.TXT are two separate files. FreeBSD does not use the extension of a
   file to determine whether the file is a program, document, or some other
   form of data.

   Files are stored in directories. A directory may contain no files, or it
   may contain many hundreds of files. A directory can also contain other
   directories, allowing a hierarchy of directories within one another in
   order to organize data.

   Files and directories are referenced by giving the file or directory name,
   followed by a forward slash, /, followed by any other directory names that
   are necessary. For example, if the directory foo contains a directory bar
   which contains the file readme.txt, the full name, or path, to the file is
   foo/bar/readme.txt. Note that this is different from Windows(R) which uses
   \ to separate file and directory names. FreeBSD does not use drive
   letters, or other drive names in the path. For example, one would not type
   c:\foo\bar\readme.txt on FreeBSD.

   Directories and files are stored in a file system. Each file system
   contains exactly one directory at the very top level, called the root
   directory for that file system. This root directory can contain other
   directories. One file system is designated the root file system or /.
   Every other file system is mounted under the root file system. No matter
   how many disks are on the FreeBSD system, every directory appears to be
   part of the same disk.

   Consider three file systems, called A, B, and C. Each file system has one
   root directory, which contains two other directories, called A1, A2 (and
   likewise B1, B2 and C1, C2).

   Call A the root file system. If ls(1) is used to view the contents of this
   directory, it will show two subdirectories, A1 and A2. The directory tree
   looks like this:

   A file system must be mounted on to a directory in another file system.
   When mounting file system B on to the directory A1, the root directory of
   B replaces A1, and the directories in B appear accordingly:

   Any files that are in the B1 or B2 directories can be reached with the
   path /A1/B1 or /A1/B2 as necessary. Any files that were in /A1 have been
   temporarily hidden. They will reappear if B is unmounted from A.

   If B had been mounted on A2 then the diagram would look like this:

   and the paths would be /A2/B1 and /A2/B2 respectively.

   File systems can be mounted on top of one another. Continuing the last
   example, the C file system could be mounted on top of the B1 directory in
   the B file system, leading to this arrangement:

   Or C could be mounted directly on to the A file system, under the A1
   directory:

   It is entirely possible to have one large root file system, and not need
   to create any others. There are some drawbacks to this approach, and one
   advantage.

   Benefits of Multiple File Systems
     * Different file systems can have different mount options. For example,
       the root file system can be mounted read-only, making it impossible
       for users to inadvertently delete or edit a critical file. Separating
       user-writable file systems, such as /home, from other file systems
       allows them to be mounted nosuid. This option prevents the suid/guid
       bits on executables stored on the file system from taking effect,
       possibly improving security.

     * FreeBSD automatically optimizes the layout of files on a file system,
       depending on how the file system is being used. So a file system that
       contains many small files that are written frequently will have a
       different optimization to one that contains fewer, larger files. By
       having one big file system this optimization breaks down.

     * FreeBSD's file systems are robust if power is lost. However, a power
       loss at a critical point could still damage the structure of the file
       system. By splitting data over multiple file systems it is more likely
       that the system will still come up, making it easier to restore from
       backup as necessary.

   Benefit of a Single File System
     * File systems are a fixed size. If you create a file system when you
       install FreeBSD and give it a specific size, you may later discover
       that you need to make the partition bigger. This is not easily
       accomplished without backing up, recreating the file system with the
       new size, and then restoring the backed up data.

  Important:

       FreeBSD features the growfs(8) command, which makes it possible to
       increase the size of file system on the fly, removing this limitation.

   File systems are contained in partitions. This does not have the same
   meaning as the common usage of the term partition (for example, MS-DOS(R)
   partition), because of FreeBSD's UNIX(R) heritage. Each partition is
   identified by a letter from a through to h. Each partition can contain
   only one file system, which means that file systems are often described by
   either their typical mount point in the file system hierarchy, or the
   letter of the partition they are contained in.

   FreeBSD also uses disk space for swap space to provide virtual memory.
   This allows your computer to behave as though it has much more memory than
   it actually does. When FreeBSD runs out of memory, it moves some of the
   data that is not currently being used to the swap space, and moves it back
   in (moving something else out) when it needs it.

   Some partitions have certain conventions associated with them.

   Partition                            Convention                            
   a         Normally contains the root file system.                          
   b         Normally contains swap space.                                    
   c         Normally the same size as the enclosing slice. This allows       
             utilities that need to work on the entire slice, such as a bad   
             block scanner, to work on the c partition. A file system would   
             not normally be created on this partition.                       
   d         Partition d used to have a special meaning associated with it,   
             although that is now gone and d may work as any normal           
             partition.                                                       

   Disks in FreeBSD are divided into slices, referred to in Windows(R) as
   partitions, which are numbered from 1 to 4. These are then divided into
   partitions, which contain file systems, and are labeled using letters.

   Slice numbers follow the device name, prefixed with an s, starting at 1.
   So "da0s1" is the first slice on the first SCSI drive. There can only be
   four physical slices on a disk, but there can be logical slices inside
   physical slices of the appropriate type. These extended slices are
   numbered starting at 5, so "ada0s5" is the first extended slice on the
   first SATA disk. These devices are used by file systems that expect to
   occupy a slice.

   Slices, "dangerously dedicated" physical drives, and other drives contain
   partitions, which are represented as letters from a to h. This letter is
   appended to the device name, so "da0a" is the a partition on the first da
   drive, which is "dangerously dedicated". "ada1s3e" is the fifth partition
   in the third slice of the second SATA disk drive.

   Finally, each disk on the system is identified. A disk name starts with a
   code that indicates the type of disk, and then a number, indicating which
   disk it is. Unlike slices, disk numbering starts at 0. Common codes are
   listed in Table 3.3, "Disk Device Names".

   When referring to a partition, include the disk name, s, the slice number,
   and then the partition letter. Examples are shown in Example 3.12, "Sample
   Disk, Slice, and Partition Names".

   Example 3.13, "Conceptual Model of a Disk" shows a conceptual model of a
   disk layout.

   When installing FreeBSD, configure the disk slices, create partitions
   within the slice to be used for FreeBSD, create a file system or swap
   space in each partition, and decide where each file system will be
   mounted.

   Table 3.3. Disk Device Names

            Drive Type                        Drive Device Name               
   SATA and IDE hard drives     ada or ad                                     
   SCSI hard drives and USB     da                                            
   storage devices              
   SATA and IDE CD-ROM drives   cd or acd                                     
   SCSI CD-ROM drives           cd                                            
   Floppy drives                fd                                            
   Assorted non-standard CD-ROM mcd for Mitsumi CD-ROM and scd for Sony       
   drives                       CD-ROM devices                                
   SCSI tape drives             sa                                            
   IDE tape drives              ast                                           
                                Examples include aacd for Adaptec(R)          
   RAID drives                  AdvancedRAID, mlxd and mlyd for Mylex(R),     
                                amrd for AMI MegaRAID(R), idad for Compaq     
                                Smart RAID, twed for 3ware(R) RAID.           

   Example 3.12. Sample Disk, Slice, and Partition Names

    Name                                Meaning                               
   ada0s1a The first partition (a) on the first slice (s1) on the first SATA  
           disk (ada0).                                                       
   da1s2e  The fifth partition (e) on the second slice (s2) on the second     
           SCSI disk (da1).                                                   

   Example 3.13. Conceptual Model of a Disk

   This diagram shows FreeBSD's view of the first SATA disk attached to the
   system. Assume that the disk is 250 GB in size, and contains an 80 GB
   slice and a 170 GB slice (MS-DOS(R) partitions). The first slice contains
   a Windows(R) NTFS file system, C:, and the second slice contains a FreeBSD
   installation. This example FreeBSD installation has four data partitions
   and a swap partition.

   The four partitions each hold a file system. Partition a is used for the
   root file system, d for /var/, e for /tmp/, and f for /usr/. Partition
   letter c refers to the entire slice, and so is not used for ordinary
   partitions.

3.7. Mounting and Unmounting File Systems

   The file system is best visualized as a tree, rooted, as it were, at /.
   /dev, /usr, and the other directories in the root directory are branches,
   which may have their own branches, such as /usr/local, and so on.

   There are various reasons to house some of these directories on separate
   file systems. /var contains the directories log/, spool/, and various
   types of temporary files, and as such, may get filled up. Filling up the
   root file system is not a good idea, so splitting /var from / is often
   favorable.

   Another common reason to contain certain directory trees on other file
   systems is if they are to be housed on separate physical disks, or are
   separate virtual disks, such as Network File System mounts, described in
   Section 30.3, "Network File System (NFS)", or CDROM drives.

  3.7.1. The fstab File

   During the boot process (Chapter 13, The FreeBSD Booting Process), file
   systems listed in /etc/fstab are automatically mounted except for the
   entries containing noauto. This file contains entries in the following
   format:

 device       /mount-point fstype     options      dumpfreq     passno

   device

           An existing device name as explained in Table 3.3, "Disk Device
           Names".

   mount-point

           An existing directory on which to mount the file system.

   fstype

           The file system type to pass to mount(8). The default FreeBSD file
           system is ufs.

   options

           Either rw for read-write file systems, or ro for read-only file
           systems, followed by any other options that may be needed. A
           common option is noauto for file systems not normally mounted
           during the boot sequence. Other options are listed in mount(8).

   dumpfreq

           Used by dump(8) to determine which file systems require dumping.
           If the field is missing, a value of zero is assumed.

   passno

           Determines the order in which file systems should be checked. File
           systems that should be skipped should have their passno set to
           zero. The root file system needs to be checked before everything
           else and should have its passno set to one. The other file systems
           should be set to values greater than one. If more than one file
           system has the same passno, fsck(8) will attempt to check file
           systems in parallel if possible.

   Refer to fstab(5) for more information on the format of /etc/fstab and its
   options.

  3.7.2. Using mount(8)

   File systems are mounted using mount(8). The most basic syntax is as
   follows:

 # mount device mountpoint

   This command provides many options which are described in mount(8), The
   most commonly used options include:

   Mount Options

   -a

           Mount all the file systems listed in /etc/fstab, except those
           marked as "noauto", excluded by the -t flag, or those that are
           already mounted.

   -d

           Do everything except for the actual mount system call. This option
           is useful in conjunction with the -v flag to determine what
           mount(8) is actually trying to do.

   -f

           Force the mount of an unclean file system (dangerous), or the
           revocation of write access when downgrading a file system's mount
           status from read-write to read-only.

   -r

           Mount the file system read-only. This is identical to using -o ro.

   -t fstype

           Mount the specified file system type or mount only file systems of
           the given type, if -a is included. "ufs" is the default file
           system type.

   -u

           Update mount options on the file system.

   -v

           Be verbose.

   -w

           Mount the file system read-write.

   The following options can be passed to -o as a comma-separated list:

   nosuid

           Do not interpret setuid or setgid flags on the file system. This
           is also a useful security option.

  3.7.3. Using umount(8)

   To unmount a file system use umount(8). This command takes one parameter
   which can be a mountpoint, device name, -a or -A.

   All forms take -f to force unmounting, and -v for verbosity. Be warned
   that -f is not generally a good idea as it might crash the computer or
   damage data on the file system.

   To unmount all mounted file systems, or just the file system types listed
   after -t, use -a or -A. Note that -A does not attempt to unmount the root
   file system.

3.8. Processes and Daemons

   FreeBSD is a multi-tasking operating system. Each program running at any
   one time is called a process. Every running command starts at least one
   new process and there are a number of system processes that are run by
   FreeBSD.

   Each process is uniquely identified by a number called a process ID (PID).
   Similar to files, each process has one owner and group, and the owner and
   group permissions are used to determine which files and devices the
   process can open. Most processes also have a parent process that started
   them. For example, the shell is a process, and any command started in the
   shell is a process which has the shell as its parent process. The
   exception is a special process called init(8) which is always the first
   process to start at boot time and which always has a PID of 1.

   Some programs are not designed to be run with continuous user input and
   disconnect from the terminal at the first opportunity. For example, a web
   server responds to web requests, rather than user input. Mail servers are
   another example of this type of application. These types of programs are
   known as daemons. The term daemon comes from Greek mythology and
   represents an entity that is neither good nor evil, and which invisibly
   performs useful tasks. This is why the BSD mascot is the cheerful-looking
   daemon with sneakers and a pitchfork.

   There is a convention to name programs that normally run as daemons with a
   trailing "d". For example, BIND is the Berkeley Internet Name Domain, but
   the actual program that executes is named. The Apache web server program
   is httpd and the line printer spooling daemon is lpd. This is only a
   naming convention. For example, the main mail daemon for the Sendmail
   application is sendmail, and not maild.

  3.8.1. Viewing Processes

   To see the processes running on the system, use ps(1) or top(1). To
   display a static list of the currently running processes, their PIDs, how
   much memory they are using, and the command they were started with, use
   ps(1). To display all the running processes and update the display every
   few seconds in order to interactively see what the computer is doing, use
   top(1).

   By default, ps(1) only shows the commands that are running and owned by
   the user. For example:

 % ps
  PID TT  STAT    TIME COMMAND
 8203  0  Ss   0:00.59 /bin/csh
 8895  0  R+   0:00.00 ps

   The output from ps(1) is organized into a number of columns. The PID
   column displays the process ID. PIDs are assigned starting at 1, go up to
   99999, then wrap around back to the beginning. However, a PID is not
   reassigned if it is already in use. The TT column shows the tty the
   program is running on and STAT shows the program's state. TIME is the
   amount of time the program has been running on the CPU. This is usually
   not the elapsed time since the program was started, as most programs spend
   a lot of time waiting for things to happen before they need to spend time
   on the CPU. Finally, COMMAND is the command that was used to start the
   program.

   A number of different options are available to change the information that
   is displayed. One of the most useful sets is auxww, where a displays
   information about all the running processes of all users, u displays the
   username and memory usage of the process' owner, x displays information
   about daemon processes, and ww causes ps(1) to display the full command
   line for each process, rather than truncating it once it gets too long to
   fit on the screen.

   The output from top(1) is similar:

 % top
 last pid:  9609;  load averages:  0.56,  0.45,  0.36              up 0+00:20:03  10:21:46
 107 processes: 2 running, 104 sleeping, 1 zombie
 CPU:  6.2% user,  0.1% nice,  8.2% system,  0.4% interrupt, 85.1% idle
 Mem: 541M Active, 450M Inact, 1333M Wired, 4064K Cache, 1498M Free
 ARC: 992M Total, 377M MFU, 589M MRU, 250K Anon, 5280K Header, 21M Other
 Swap: 2048M Total, 2048M Free

   PID USERNAME    THR PRI NICE   SIZE    RES STATE   C   TIME   WCPU COMMAND
   557 root          1 -21  r31   136M 42296K select  0   2:20  9.96% Xorg
  8198 dru           2  52    0   449M 82736K select  3   0:08  5.96% kdeinit4
  8311 dru          27  30    0  1150M   187M uwait   1   1:37  0.98% firefox
   431 root          1  20    0 14268K  1728K select  0   0:06  0.98% moused
  9551 dru           1  21    0 16600K  2660K CPU3    3   0:01  0.98% top
  2357 dru           4  37    0   718M   141M select  0   0:21  0.00% kdeinit4
  8705 dru           4  35    0   480M    98M select  2   0:20  0.00% kdeinit4
  8076 dru           6  20    0   552M   113M uwait   0   0:12  0.00% soffice.bin
  2623 root          1  30   10 12088K  1636K select  3   0:09  0.00% powerd
  2338 dru           1  20    0   440M 84532K select  1   0:06  0.00% kwin
  1427 dru           5  22    0   605M 86412K select  1   0:05  0.00% kdeinit4

   The output is split into two sections. The header (the first five or six
   lines) shows the PID of the last process to run, the system load averages
   (which are a measure of how busy the system is), the system uptime (time
   since the last reboot) and the current time. The other figures in the
   header relate to how many processes are running, how much memory and swap
   space has been used, and how much time the system is spending in different
   CPU states. If the ZFS file system module has been loaded, an ARC line
   indicates how much data was read from the memory cache instead of from
   disk.

   Below the header is a series of columns containing similar information to
   the output from ps(1), such as the PID, username, amount of CPU time, and
   the command that started the process. By default, top(1) also displays the
   amount of memory space taken by the process. This is split into two
   columns: one for total size and one for resident size. Total size is how
   much memory the application has needed and the resident size is how much
   it is actually using now.

   top(1) automatically updates the display every two seconds. A different
   interval can be specified with -s.

  3.8.2. Killing Processes

   One way to communicate with any running process or daemon is to send a
   signal using kill(1). There are a number of different signals; some have a
   specific meaning while others are described in the application's
   documentation. A user can only send a signal to a process they own and
   sending a signal to someone else's process will result in a permission
   denied error. The exception is the root user, who can send signals to
   anyone's processes.

   The operating system can also send a signal to a process. If an
   application is badly written and tries to access memory that it is not
   supposed to, FreeBSD will send the process the "Segmentation Violation"
   signal (SIGSEGV). If an application has been written to use the alarm(3)
   system call to be alerted after a period of time has elapsed, it will be
   sent the "Alarm" signal (SIGALRM).

   Two signals can be used to stop a process: SIGTERM and SIGKILL. SIGTERM is
   the polite way to kill a process as the process can read the signal, close
   any log files it may have open, and attempt to finish what it is doing
   before shutting down. In some cases, a process may ignore SIGTERM if it is
   in the middle of some task that cannot be interrupted.

   SIGKILL cannot be ignored by a process. Sending a SIGKILL to a process
   will usually stop that process there and then. [1].

   Other commonly used signals are SIGHUP, SIGUSR1, and SIGUSR2. Since these
   are general purpose signals, different applications will respond
   differently.

   For example, after changing a web server's configuration file, the web
   server needs to be told to re-read its configuration. Restarting httpd
   would result in a brief outage period on the web server. Instead, send the
   daemon the SIGHUP signal. Be aware that different daemons will have
   different behavior, so refer to the documentation for the daemon to
   determine if SIGHUP will achieve the desired results.

   Procedure 3.1. Sending a Signal to a Process

   This example shows how to send a signal to inetd(8). The inetd(8)
   configuration file is /etc/inetd.conf, and inetd(8) will re-read this
   configuration file when it is sent a SIGHUP.

    1. Find the PID of the process to send the signal to using pgrep(1). In
       this example, the PID for inetd(8) is 198:

 % pgrep -l inetd
 198  inetd -wW

    2. Use kill(1) to send the signal. As inetd(8) is owned by root, use
       su(1) to become root first.

 % su
 Password:
 # /bin/kill -s HUP 198

       Like most UNIX(R) commands, kill(1) will not print any output if it is
       successful. If a signal is sent to a process not owned by that user,
       the message kill: PID: Operation not permitted will be displayed.
       Mistyping the PID will either send the signal to the wrong process,
       which could have negative results, or will send the signal to a PID
       that is not currently in use, resulting in the error kill: PID: No
       such process.

  Why Use /bin/kill?:

       Many shells provide kill as a built in command, meaning that the shell
       will send the signal directly, rather than running /bin/kill. Be aware
       that different shells have a different syntax for specifying the name
       of the signal to send. Rather than try to learn all of them, it can be
       simpler to specify /bin/kill.

   When sending other signals, substitute TERM or KILL with the name of the
   signal.

  Important:

   Killing a random process on the system is a bad idea. In particular,
   init(8), PID 1, is special. Running /bin/kill -s KILL 1 is a quick, and
   unrecommended, way to shutdown the system. Always double check the
   arguments to kill(1) before pressing Return.

3.9. Shells

   A shell provides a command line interface for interacting with the
   operating system. A shell receives commands from the input channel and
   executes them. Many shells provide built in functions to help with
   everyday tasks such as file management, file globbing, command line
   editing, command macros, and environment variables. FreeBSD comes with
   several shells, including the Bourne shell (sh(1)) and the extended C
   shell (tcsh(1)). Other shells are available from the FreeBSD Ports
   Collection, such as zsh and bash.

   The shell that is used is really a matter of taste. A C programmer might
   feel more comfortable with a C-like shell such as tcsh(1). A Linux(R) user
   might prefer bash. Each shell has unique properties that may or may not
   work with a user's preferred working environment, which is why there is a
   choice of which shell to use.

   One common shell feature is filename completion. After a user types the
   first few letters of a command or filename and presses Tab, the shell
   completes the rest of the command or filename. Consider two files called
   foobar and football. To delete foobar, the user might type rm foo and
   press Tab to complete the filename.

   But the shell only shows rm foo. It was unable to complete the filename
   because both foobar and football start with foo. Some shells sound a beep
   or show all the choices if more than one name matches. The user must then
   type more characters to identify the desired filename. Typing a t and
   pressing Tab again is enough to let the shell determine which filename is
   desired and fill in the rest.

   Another feature of the shell is the use of environment variables.
   Environment variables are a variable/key pair stored in the shell's
   environment. This environment can be read by any program invoked by the
   shell, and thus contains a lot of program configuration. Table 3.4,
   "Common Environment Variables" provides a list of common environment
   variables and their meanings. Note that the names of environment variables
   are always in uppercase.

   Table 3.4. Common Environment Variables

   Variable                            Description                            
   USER     Current logged in user's name.                                    
   PATH     Colon-separated list of directories to search for binaries.       
   DISPLAY  Network name of the Xorg display to connect to, if available.     
   SHELL    The current shell.                                                
   TERM     The name of the user's type of terminal. Used to determine the    
            capabilities of the terminal.                                     
   TERMCAP  Database entry of the terminal escape codes to perform various    
            terminal functions.                                               
   OSTYPE   Type of operating system.                                         
   MACHTYPE The system's CPU architecture.                                    
   EDITOR   The user's preferred text editor.                                 
   PAGER    The user's preferred utility for viewing text one page at a time. 
   MANPATH  Colon-separated list of directories to search for manual pages.   

   How to set an environment variable differs between shells. In tcsh(1) and
   csh(1), use setenv to set environment variables. In sh(1) and bash, use
   export to set the current environment variables. This example sets the
   default EDITOR to /usr/local/bin/emacs for the tcsh(1) shell:

 % setenv EDITOR /usr/local/bin/emacs

   The equivalent command for bash would be:

 % export EDITOR="/usr/local/bin/emacs"

   To expand an environment variable in order to see its current setting,
   type a $ character in front of its name on the command line. For example,
   echo $TERM displays the current $TERM setting.

   Shells treat special characters, known as meta-characters, as special
   representations of data. The most common meta-character is *, which
   represents any number of characters in a filename. Meta-characters can be
   used to perform filename globbing. For example, echo * is equivalent to ls
   because the shell takes all the files that match * and echo lists them on
   the command line.

   To prevent the shell from interpreting a special character, escape it from
   the shell by starting it with a backslash (\). For example, echo $TERM
   prints the terminal setting whereas echo \$TERM literally prints the
   string $TERM.

  3.9.1. Changing the Shell

   The easiest way to permanently change the default shell is to use chsh.
   Running this command will open the editor that is configured in the EDITOR
   environment variable, which by default is set to vi(1). Change the Shell:
   line to the full path of the new shell.

   Alternately, use chsh -s which will set the specified shell without
   opening an editor. For example, to change the shell to bash:

 % chsh -s /usr/local/bin/bash

  Note:

   The new shell must be present in /etc/shells. If the shell was installed
   from the FreeBSD Ports Collection as described in Chapter 4, Installing
   Applications: Packages and Ports, it should be automatically added to this
   file. If it is missing, add it using this command, replacing the path with
   the path of the shell:

 # echo /usr/local/bin/bash >> /etc/shells

   Then, rerun chsh(1).

  3.9.2. Advanced Shell Techniques

   Written by Tom Rhodes.

   The UNIX(R) shell is not just a command interpreter, it acts as a powerful
   tool which allows users to execute commands, redirect their output,
   redirect their input and chain commands together to improve the final
   command output. When this functionality is mixed with built in commands,
   the user is provided with an environment that can maximize efficiency.

   Shell redirection is the action of sending the output or the input of a
   command into another command or into a file. To capture the output of the
   ls(1) command, for example, into a file, redirect the output:

 % ls > directory_listing.txt

   The directory contents will now be listed in directory_listing.txt. Some
   commands can be used to read input, such as sort(1). To sort this listing,
   redirect the input:

 % sort < directory_listing.txt

   The input will be sorted and placed on the screen. To redirect that input
   into another file, one could redirect the output of sort(1) by mixing the
   direction:

 % sort < directory_listing.txt > sorted.txt

   In all of the previous examples, the commands are performing redirection
   using file descriptors. Every UNIX(R) system has file descriptors, which
   include standard input (stdin), standard output (stdout), and standard
   error (stderr). Each one has a purpose, where input could be a keyboard or
   a mouse, something that provides input. Output could be a screen or paper
   in a printer. And error would be anything that is used for diagnostic or
   error messages. All three are considered I/O based file descriptors and
   sometimes considered streams.

   Through the use of these descriptors, the shell allows output and input to
   be passed around through various commands and redirected to or from a
   file. Another method of redirection is the pipe operator.

   The UNIX(R) pipe operator, "|" allows the output of one command to be
   directly passed or directed to another program. Basically, a pipe allows
   the standard output of a command to be passed as standard input to another
   command, for example:

 % cat directory_listing.txt | sort | less

   In that example, the contents of directory_listing.txt will be sorted and
   the output passed to less(1). This allows the user to scroll through the
   output at their own pace and prevent it from scrolling off the screen.

3.10. Text Editors

   Most FreeBSD configuration is done by editing text files, so it is a good
   idea to become familiar with a text editor. FreeBSD comes with a few as
   part of the base system, and many more are available in the Ports
   Collection.

   A simple editor to learn is ee(1), which stands for easy editor. To start
   this editor, type ee filename where filename is the name of the file to be
   edited. Once inside the editor, all of the commands for manipulating the
   editor's functions are listed at the top of the display. The caret (^)
   represents Ctrl, so ^e expands to Ctrl+e. To leave ee(1), press Esc, then
   choose the "leave editor" option from the main menu. The editor will
   prompt to save any changes if the file has been modified.

   FreeBSD also comes with more powerful text editors, such as vi(1), as part
   of the base system. Other editors, like editors/emacs and editors/vim, are
   part of the FreeBSD Ports Collection. These editors offer more
   functionality at the expense of being more complicated to learn. Learning
   a more powerful editor such as vim or Emacs can save more time in the long
   run.

   Many applications which modify files or require typed input will
   automatically open a text editor. To change the default editor, set the
   EDITOR environment variable as described in Section 3.9, "Shells".

3.11. Devices and Device Nodes

   A device is a term used mostly for hardware-related activities in a
   system, including disks, printers, graphics cards, and keyboards. When
   FreeBSD boots, the majority of the boot messages refer to devices being
   detected. A copy of the boot messages are saved to /var/run/dmesg.boot.

   Each device has a device name and number. For example, ada0 is the first
   SATA hard drive, while kbd0 represents the keyboard.

   Most devices in FreeBSD must be accessed through special files called
   device nodes, which are located in /dev.

3.12. Manual Pages

   The most comprehensive documentation on FreeBSD is in the form of manual
   pages. Nearly every program on the system comes with a short reference
   manual explaining the basic operation and available arguments. These
   manuals can be viewed using man:

 % man command

   where command is the name of the command to learn about. For example, to
   learn more about ls(1), type:

 % man ls

   Manual pages are divided into sections which represent the type of topic.
   In FreeBSD, the following sections are available:

    1. User commands.

    2. System calls and error numbers.

    3. Functions in the C libraries.

    4. Device drivers.

    5. File formats.

    6. Games and other diversions.

    7. Miscellaneous information.

    8. System maintenance and operation commands.

    9. System kernel interfaces.

   In some cases, the same topic may appear in more than one section of the
   online manual. For example, there is a chmod user command and a chmod()
   system call. To tell man(1) which section to display, specify the section
   number:

 % man 1 chmod

   This will display the manual page for the user command chmod(1).
   References to a particular section of the online manual are traditionally
   placed in parenthesis in written documentation, so chmod(1) refers to the
   user command and chmod(2) refers to the system call.

   If the name of the manual page is unknown, use man -k to search for
   keywords in the manual page descriptions:

 % man -k mail

   This command displays a list of commands that have the keyword "mail" in
   their descriptions. This is equivalent to using apropos(1).

   To read the descriptions for all of the commands in /usr/bin, type:

 % cd /usr/bin
 % man -f * | more

   or

 % cd /usr/bin
 % whatis * |more

  3.12.1. GNU Info Files

   FreeBSD includes several applications and utilities produced by the Free
   Software Foundation (FSF). In addition to manual pages, these programs may
   include hypertext documents called info files. These can be viewed using
   info(1) or, if editors/emacs is installed, the info mode of emacs.

   To use info(1), type:

 % info

   For a brief introduction, type h. For a quick command reference, type ?.

     ----------------------------------------------------------------------

   [1] There are a few tasks that cannot be interrupted. For example, if the
   process is trying to read from a file that is on another computer on the
   network, and the other computer is unavailable, the process is said to be
   "uninterruptible". Eventually the process will time out, typically after
   two minutes. As soon as this time out occurs the process will be killed.

Chapter 4. Installing Applications: Packages and Ports

   Table of Contents

   4.1. Synopsis

   4.2. Overview of Software Installation

   4.3. Finding Software

   4.4. Using pkg for Binary Package Management

   4.5. Using the Ports Collection

   4.6. Building Packages with Poudriere

   4.7. Post-Installation Considerations

   4.8. Dealing with Broken Ports

4.1. Synopsis

   FreeBSD is bundled with a rich collection of system tools as part of the
   base system. In addition, FreeBSD provides two complementary technologies
   for installing third-party software: the FreeBSD Ports Collection, for
   installing from source, and packages, for installing from pre-built
   binaries. Either method may be used to install software from local media
   or from the network.

   After reading this chapter, you will know:

     * The difference between binary packages and ports.

     * How to find third-party software that has been ported to FreeBSD.

     * How to manage binary packages using pkg.

     * How to build third-party software from source using the Ports
       Collection.

     * How to find the files installed with the application for
       post-installation configuration.

     * What to do if a software installation fails.

4.2. Overview of Software Installation

   The typical steps for installing third-party software on a UNIX(R) system
   include:

    1. Find and download the software, which might be distributed in source
       code format or as a binary.

    2. Unpack the software from its distribution format. This is typically a
       tarball compressed with a program such as compress(1), gzip(1),
       bzip2(1) or xz(1).

    3. Locate the documentation in INSTALL, README or some file in a doc/
       subdirectory and read up on how to install the software.

    4. If the software was distributed in source format, compile it. This may
       involve editing a Makefile or running a configure script.

    5. Test and install the software.

   A FreeBSD port is a collection of files designed to automate the process
   of compiling an application from source code. The files that comprise a
   port contain all the necessary information to automatically download,
   extract, patch, compile, and install the application.

   If the software has not already been adapted and tested on FreeBSD, the
   source code might need editing in order for it to install and run
   properly.

   However, over 24,000 third-party applications have already been ported to
   FreeBSD. When feasible, these applications are made available for download
   as pre-compiled packages.

   Packages can be manipulated with the FreeBSD package management commands.

   Both packages and ports understand dependencies. If a package or port is
   used to install an application and a dependent library is not already
   installed, the library will automatically be installed first.

   A FreeBSD package contains pre-compiled copies of all the commands for an
   application, as well as any configuration files and documentation. A
   package can be manipulated with the pkg(8) commands, such as pkg install.

   While the two technologies are similar, packages and ports each have their
   own strengths. Select the technology that meets your requirements for
   installing a particular application.

   Package Benefits
     * A compressed package tarball is typically smaller than the compressed
       tarball containing the source code for the application.

     * Packages do not require compilation time. For large applications, such
       as Mozilla, KDE, or GNOME, this can be important on a slow system.

     * Packages do not require any understanding of the process involved in
       compiling software on FreeBSD.

   Port Benefits
     * Packages are normally compiled with conservative options because they
       have to run on the maximum number of systems. By compiling from the
       port, one can change the compilation options.

     * Some applications have compile-time options relating to which features
       are installed. For example, Apache can be configured with a wide
       variety of different built-in options.

       In some cases, multiple packages will exist for the same application
       to specify certain settings. For example, Ghostscript is available as
       a ghostscript package and a ghostscript-nox11 package, depending on
       whether or not Xorg is installed. Creating multiple packages rapidly
       becomes impossible if an application has more than one or two
       different compile-time options.

     * The licensing conditions of some software forbid binary distribution.
       Such software must be distributed as source code which must be
       compiled by the end-user.

     * Some people do not trust binary distributions or prefer to read
       through source code in order to look for potential problems.

     * Source code is needed in order to apply custom patches.

   To keep track of updated ports, subscribe to the FreeBSD ports mailing
   list and the FreeBSD ports bugs mailing list.

  Warning:

   Before installing any application, check https://vuxml.freebsd.org/ for
   security issues related to the application or type pkg audit -F to check
   all installed applications for known vulnerabilities.

   The remainder of this chapter explains how to use packages and ports to
   install and manage third-party software on FreeBSD.

4.3. Finding Software

   FreeBSD's list of available applications is growing all the time. There
   are a number of ways to find software to install:

     * The FreeBSD web site maintains an up-to-date searchable list of all
       the available applications, at https://www.FreeBSD.org/ports/. The
       ports can be searched by application name or by software category.

     * Dan Langille maintains FreshPorts.org which provides a comprehensive
       search utility and also tracks changes to the applications in the
       Ports Collection. Registered users can create a customized watch list
       in order to receive an automated email when their watched ports are
       updated.

     * If finding a particular application becomes challenging, try searching
       a site like SourceForge.net or GitHub.com then check back at the
       FreeBSD site to see if the application has been ported.

     * To search the binary package repository for an application:

 # pkg search subversion
 git-subversion-1.9.2
 java-subversion-1.8.8_2
 p5-subversion-1.8.8_2
 py27-hgsubversion-1.6
 py27-subversion-1.8.8_2
 ruby-subversion-1.8.8_2
 subversion-1.8.8_2
 subversion-book-4515
 subversion-static-1.8.8_2
 subversion16-1.6.23_4
 subversion17-1.7.16_2

       Package names include the version number and, in the case of ports
       based on python, the version number of the version of python the
       package was built with. Some ports also have multiple versions
       available. In the case of Subversion, there are different versions
       available, as well as different compile options. In this case, the
       statically linked version of Subversion. When indicating which package
       to install, it is best to specify the application by the port origin,
       which is the path in the ports tree. Repeat the pkg search with -o to
       list the origin of each package:

 # pkg search -o subversion
 devel/git-subversion
 java/java-subversion
 devel/p5-subversion
 devel/py-hgsubversion
 devel/py-subversion
 devel/ruby-subversion
 devel/subversion16
 devel/subversion17
 devel/subversion
 devel/subversion-book
 devel/subversion-static

       Searching by shell globs, regular expressions, exact match, by
       description, or any other field in the repository database is also
       supported by pkg search. After installing ports-mgmt/pkg or
       ports-mgmt/pkg-devel, see pkg-search(8) for more details.

     * If the Ports Collection is already installed, there are several
       methods to query the local version of the ports tree. To find out
       which category a port is in, type whereis file, where file is the
       program to be installed:

 # whereis lsof
 lsof: /usr/ports/sysutils/lsof

       Alternately, an echo(1) statement can be used:

 # echo /usr/ports/*/*lsof*
 /usr/ports/sysutils/lsof

       Note that this will also return any matched files downloaded into the
       /usr/ports/distfiles directory.

     * Another way to find software is by using the Ports Collection's
       built-in search mechanism. To use the search feature, cd to /usr/ports
       then run make search name=program-name where program-name is the name
       of the software. For example, to search for lsof:

 # cd /usr/ports
 # make search name=lsof
 Port:   lsof-4.88.d,8
 Path:   /usr/ports/sysutils/lsof
 Info:   Lists information about open files (similar to fstat(1))
 Maint:  ler@lerctr.org
 Index:  sysutils
 B-deps:
 R-deps:

  Tip:

       The built-in search mechanism uses a file of index information. If a
       message indicates that the INDEX is required, run make fetchindex to
       download the current index file. With the INDEX present, make search
       will be able to perform the requested search.

       The "Path:" line indicates where to find the port.

       To receive less information, use the quicksearch feature:

 # cd /usr/ports
 # make quicksearch name=lsof
 Port:   lsof-4.88.d,8
 Path:   /usr/ports/sysutils/lsof
 Info:   Lists information about open files (similar to fstat(1))

       For more in-depth searching, use make search key=string or make
       quicksearch key=string, where string is some text to search for. The
       text can be in comments, descriptions, or dependencies in order to
       find ports which relate to a particular subject when the name of the
       program is unknown.

       When using search or quicksearch, the search string is
       case-insensitive. Searching for "LSOF" will yield the same results as
       searching for "lsof".

4.4. Using pkg for Binary Package Management

   pkg is the next generation replacement for the traditional FreeBSD package
   management tools, offering many features that make dealing with binary
   packages faster and easier.

   For sites wishing to only use prebuilt binary packages from the FreeBSD
   mirrors, managing packages with pkg can be sufficient.

   However, for those sites building from source or using their own
   repositories, a separate port management tool will be needed.

   Since pkg only works with binary packages, it is not a replacement for
   such tools. Those tools can be used to install software from both binary
   packages and the Ports Collection, while pkg installs only binary
   packages.

  4.4.1. Getting Started with pkg

   FreeBSD includes a bootstrap utility which can be used to download and
   install pkg and its manual pages. This utility is designed to work with
   versions of FreeBSD starting with 10.X.

  Note:

   Not all FreeBSD versions and architectures support this bootstrap process.
   The current list is at https://pkg.freebsd.org/. For other cases, pkg must
   instead be installed from the Ports Collection or as a binary package.

   To bootstrap the system, run:

 # /usr/sbin/pkg

   You must have a working Internet connection for the bootstrap process to
   succeed.

   Otherwise, to install the port, run:

 # cd /usr/ports/ports-mgmt/pkg
 # make
 # make install clean

   When upgrading an existing system that originally used the older pkg_*
   tools, the database must be converted to the new format, so that the new
   tools are aware of the already installed packages. Once pkg has been
   installed, the package database must be converted from the traditional
   format to the new format by running this command:

 # pkg2ng

  Note:

   This step is not required for new installations that do not yet have any
   third-party software installed.

  Important:

   This step is not reversible. Once the package database has been converted
   to the pkg format, the traditional pkg_* tools should no longer be used.

  Note:

   The package database conversion may emit errors as the contents are
   converted to the new version. Generally, these errors can be safely
   ignored. However, a list of software that was not successfully converted
   is shown after pkg2ng finishes. These applications must be manually
   reinstalled.

   To ensure that the Ports Collection registers new software with pkg
   instead of the traditional packages database, FreeBSD versions earlier
   than 10.X require this line in /etc/make.conf:

 WITH_PKGNG=     yes

   By default, pkg uses the binary packages from the FreeBSD package mirrors
   (the repository). For information about building a custom package
   repository, see Section 4.6, "Building Packages with Poudriere".

   Additional pkg configuration options are described in pkg.conf(5).

   Usage information for pkg is available in the pkg(8) manual page or by
   running pkg without additional arguments.

   Each pkg command argument is documented in a command-specific manual page.
   To read the manual page for pkg install, for example, run either of these
   commands:

 # pkg help install

 # man pkg-install

   The rest of this section demonstrates common binary package management
   tasks which can be performed using pkg. Each demonstrated command provides
   many switches to customize its use. Refer to a command's help or man page
   for details and more examples.

  4.4.2. Quarterly and Latest Ports Branches

   The Quarterly branch provides users with a more predictable and stable
   experience for port and package installation and upgrades. This is done
   essentially by only allowing non-feature updates. Quarterly branches aim
   to receive security fixes (that may be version updates, or backports of
   commits), bug fixes and ports compliance or framework changes. The
   Quarterly branch is cut from HEAD at the beginning of every (yearly)
   quarter in January, April, July, and October. Branches are named according
   to the year (YYYY) and quarter (Q1-4) they are created in. For example,
   the quarterly branch created in January 2016, is named 2016Q1. And the
   Latest branch provides the latest versions of the packages to the users.

   To switch from quarterly to latest run the following commands:

 # cp /etc/pkg/FreeBSD.conf /usr/local/etc/pkg/repos/FreeBSD.conf

   Edit the file /usr/local/etc/pkg/repos/FreeBSD.conf and change the string
   quarterly to latest in the url: line.

   The result should be similar to the following:

 FreeBSD: {
   url: "pkg+http://pkg.FreeBSD.org/${ABI}/latest",
   mirror_type: "srv",
   signature_type: "fingerprints",
   fingerprints: "/usr/share/keys/pkg",
   enabled: yes
 }

   And finally run this command to update from the new (latest) repository
   metadata.

 # pkg update -f

  4.4.3. Obtaining Information About Installed Packages

   Information about the packages installed on a system can be viewed by
   running pkg info which, when run without any switches, will list the
   package version for either all installed packages or the specified
   package.

   For example, to see which version of pkg is installed, run:

 # pkg info pkg
 pkg-1.1.4_1

  4.4.4. Installing and Removing Packages

   To install a binary package use the following command, where packagename
   is the name of the package to install:

 # pkg install packagename

   This command uses repository data to determine which version of the
   software to install and if it has any uninstalled dependencies. For
   example, to install curl:

 # pkg install curl
 Updating repository catalogue
 /usr/local/tmp/All/curl-7.31.0_1.txz          100% of 1181 kB 1380 kBps 00m01s

 /usr/local/tmp/All/ca_root_nss-3.15.1_1.txz   100% of  288 kB 1700 kBps 00m00s

 Updating repository catalogue
 The following 2 packages will be installed:

         Installing ca_root_nss: 3.15.1_1
         Installing curl: 7.31.0_1

 The installation will require 3 MB more space

 0 B to be downloaded

 Proceed with installing packages [y/N]: y
 Checking integrity... done
 [1/2] Installing ca_root_nss-3.15.1_1... done
 [2/2] Installing curl-7.31.0_1... done
 Cleaning up cache files...Done

   The new package and any additional packages that were installed as
   dependencies can be seen in the installed packages list:

 # pkg info
 ca_root_nss-3.15.1_1    The root certificate bundle from the Mozilla Project
 curl-7.31.0_1   Non-interactive tool to get files from FTP, GOPHER, HTTP(S) servers
 pkg-1.1.4_6     New generation package manager

   Packages that are no longer needed can be removed with pkg delete. For
   example:

 # pkg delete curl
 The following packages will be deleted:

         curl-7.31.0_1

 The deletion will free 3 MB

 Proceed with deleting packages [y/N]: y
 [1/1] Deleting curl-7.31.0_1... done

  4.4.5. Upgrading Installed Packages

   Installed packages can be upgraded to their latest versions by running:

 # pkg upgrade

   This command will compare the installed versions with those available in
   the repository catalogue and upgrade them from the repository.

  4.4.6. Auditing Installed Packages

   Software vulnerabilities are regularly discovered in third-party
   applications. To address this, pkg includes a built-in auditing mechanism.
   To determine if there are any known vulnerabilities for the software
   installed on the system, run:

 # pkg audit -F

  4.4.7. Automatically Removing Unused Packages

   Removing a package may leave behind dependencies which are no longer
   required. Unneeded packages that were installed as dependencies (leaf
   packages) can be automatically detected and removed using:

 # pkg autoremove
 Packages to be autoremoved:
         ca_root_nss-3.15.1_1

 The autoremoval will free 723 kB

 Proceed with autoremoval of packages [y/N]: y
 Deinstalling ca_root_nss-3.15.1_1... done

   Packages installed as dependencies are called automatic packages.
   Non-automatic packages, i.e the packages that were explicity installed not
   as a dependency to another package, can be listed using:

 # pkg prime-list
 nginx
 openvpn
 sudo

   pkg prime-list is an alias command declared in /usr/local/etc/pkg.conf.
   There are many others that can be used to query the package database of
   the system. For instance, command pkg prime-origins can be used to get the
   origin port directory of the list mentioned above:

 # pkg prime-origins
 www/nginx
 security/openvpn
 security/sudo

   This list can be used to rebuild all packages installed on a system using
   build tools such as ports-mgmt/poudriere or ports-mgmt/synth.

   Marking an installed package as automatic can be done using:

 # pkg set -A 1 devel/cmake

   Once a package is a leaf package and is marked as automatic, it gets
   selected by pkg autoremove.

   Marking an installed package as not automatic can be done using:

 # pkg set -A 0 devel/cmake

  4.4.8. Restoring the Package Database

   Unlike the traditional package management system, pkg includes its own
   package database backup mechanism. This functionality is enabled by
   default.

  Tip:

   To disable the periodic script from backing up the package database, set
   daily_backup_pkgdb_enable="NO" in periodic.conf(5).

   To restore the contents of a previous package database backup, run the
   following command replacing /path/to/pkg.sql with the location of the
   backup:

 # pkg backup -r /path/to/pkg.sql

  Note:

   If restoring a backup taken by the periodic script, it must be
   decompressed prior to being restored.

   To run a manual backup of the pkg database, run the following command,
   replacing /path/to/pkg.sql with a suitable file name and location:

 # pkg backup -d /path/to/pkg.sql

  4.4.9. Removing Stale Packages

   By default, pkg stores binary packages in a cache directory defined by
   PKG_CACHEDIR in pkg.conf(5). Only copies of the latest installed packages
   are kept. Older versions of pkg kept all previous packages. To remove
   these outdated binary packages, run:

 # pkg clean

   The entire cache may be cleared by running:

 # pkg clean -a

  4.4.10. Modifying Package Metadata

   Software within the FreeBSD Ports Collection can undergo major version
   number changes. To address this, pkg has a built-in command to update
   package origins. This can be useful, for example, if lang/php5 is renamed
   to lang/php53 so that lang/php5 can now represent version 5.4.

   To change the package origin for the above example, run:

 # pkg set -o lang/php5:lang/php53

   As another example, to update lang/ruby18 to lang/ruby19, run:

 # pkg set -o lang/ruby18:lang/ruby19

   As a final example, to change the origin of the libglut shared libraries
   from graphics/libglut to graphics/freeglut, run:

 # pkg set -o graphics/libglut:graphics/freeglut

  Note:

   When changing package origins, it is important to reinstall packages that
   are dependent on the package with the modified origin. To force a
   reinstallation of dependent packages, run:

 # pkg install -Rf graphics/freeglut

4.5. Using the Ports Collection

   The Ports Collection is a set of Makefiles, patches, and description
   files. Each set of these files is used to compile and install an
   individual application on FreeBSD, and is called a port.

   By default, the Ports Collection itself is stored as a subdirectory of
   /usr/ports.

  Warning:

   Before installing and using the Ports Collection, please be aware that it
   is generally ill-advised to use the Ports Collection in conjunction with
   the binary packages provided via pkg to install software. pkg, by default,
   tracks quarterly branch-releases of the ports tree and not HEAD.
   Dependencies could be different for a port in HEAD compared to its
   counterpart in a quarterly branch release and this could result in
   conflicts between dependencies installed by pkg and those from the Ports
   Collection. If the Ports Collection and pkg must be used in conjunction,
   then be sure that your Ports Collection and pkg are on the same branch
   release of the ports tree.

   Before an application can be compiled using a port, the Ports Collection
   must first be installed. If it was not installed during the installation
   of FreeBSD, use one of the following methods to install it:

   Procedure 4.1. Portsnap Method

   The base system of FreeBSD includes Portsnap. This is a fast and
   user-friendly tool for retrieving the Ports Collection and is the
   recommended choice for most users not running FreeBSD-CURRENT. This
   utility connects to a FreeBSD site, verifies the secure key, and downloads
   a new copy of the Ports Collection. The key is used to verify the
   integrity of all downloaded files.

    1. To download a compressed snapshot of the Ports Collection into
       /var/db/portsnap:

 # portsnap fetch

    2. When running Portsnap for the first time, extract the snapshot into
       /usr/ports:

 # portsnap extract

    3. After the first use of Portsnap has been completed as shown above,
       /usr/ports can be updated as needed by running:

 # portsnap fetch
 # portsnap update

       When using fetch, the extract or the update operation may be run
       consecutively, like so:

 # portsnap fetch update

   Procedure 4.2. Subversion Method

   If more control over the ports tree is needed or if local changes need to
   be maintained, or if running FreeBSD-CURRENT, Subversion can be used to
   obtain the Ports Collection. Refer to the Subversion Primer for a detailed
   description of Subversion.

    1. Subversion must be installed before it can be used to check out the
       ports tree. If a copy of the ports tree is already present, install
       Subversion like this:

 # cd /usr/ports/devel/subversion
 # make install clean

       If the ports tree is not available, or pkg is being used to manage
       packages, Subversion can be installed as a package:

 # pkg install subversion

    2. Check out a copy of the HEAD branch of the ports tree:

 # svn checkout https://svn.FreeBSD.org/ports/head /usr/ports

    3. Or, check out a copy of a quarterly branch:

 # svn checkout https://svn.FreeBSD.org/ports/branches/2020Q3 /usr/ports

    4. As needed, update /usr/ports after the initial Subversion checkout:

 # svn update /usr/ports

    5. As needed, switch /usr/ports to a different quarterly branch:

 # svn switch http://svn.freebsd.org/ports/branches/2020Q4/ /usr/ports

   The Ports Collection contains directories for software categories. Inside
   each category are subdirectories for individual applications. Each
   application subdirectory contains a set of files that tells FreeBSD how to
   compile and install that program, called a ports skeleton. Each port
   skeleton includes these files and directories:

     * Makefile: contains statements that specify how the application should
       be compiled and where its components should be installed.

     * distinfo: contains the names and checksums of the files that must be
       downloaded to build the port.

     * files/: this directory contains any patches needed for the program to
       compile and install on FreeBSD. This directory may also contain other
       files used to build the port.

     * pkg-descr: provides a more detailed description of the program.

     * pkg-plist: a list of all the files that will be installed by the port.
       It also tells the ports system which files to remove upon
       deinstallation.

   Some ports include pkg-message or other files to handle special
   situations. For more details on these files, and on ports in general,
   refer to the FreeBSD Porter's Handbook.

   The port does not include the actual source code, also known as a
   distfile. The extract portion of building a port will automatically save
   the downloaded source to /usr/ports/distfiles.

  4.5.1. Installing Ports

   This section provides basic instructions on using the Ports Collection to
   install or remove software. The detailed description of available make
   targets and environment variables is available in ports(7).

  Warning:

   Before compiling any port, be sure to update the Ports Collection as
   described in the previous section. Since the installation of any
   third-party software can introduce security vulnerabilities, it is
   recommended to first check https://vuxml.freebsd.org/ for known security
   issues related to the port. Alternately, run pkg audit -F before
   installing a new port. This command can be configured to automatically
   perform a security audit and an update of the vulnerability database
   during the daily security system check. For more information, refer to
   pkg-audit(8) and periodic(8).

   Using the Ports Collection assumes a working Internet connection. It also
   requires superuser privilege.

   To compile and install the port, change to the directory of the port to be
   installed, then type make install at the prompt. Messages will indicate
   the progress:

 # cd /usr/ports/sysutils/lsof
 # make install
 >> lsof_4.88D.freebsd.tar.gz doesn't seem to exist in /usr/ports/distfiles/.
 >> Attempting to fetch from ftp://lsof.itap.purdue.edu/pub/tools/unix/lsof/.
 ===>  Extracting for lsof-4.88
 ...
 [extraction output snipped]
 ...
 >> Checksum OK for lsof_4.88D.freebsd.tar.gz.
 ===>  Patching for lsof-4.88.d,8
 ===>  Applying FreeBSD patches for lsof-4.88.d,8
 ===>  Configuring for lsof-4.88.d,8
 ...
 [configure output snipped]
 ...
 ===>  Building for lsof-4.88.d,8
 ...
 [compilation output snipped]
 ...

 ===>  Installing for lsof-4.88.d,8
 ...
 [installation output snipped]
 ...
 ===>   Generating temporary packing list
 ===>   Compressing manual pages for lsof-4.88.d,8
 ===>   Registering installation for lsof-4.88.d,8
 ===>  SECURITY NOTE:
       This port has installed the following binaries which execute with
       increased privileges.
 /usr/local/sbin/lsof
 #

   Since lsof is a program that runs with increased privileges, a security
   warning is displayed as it is installed. Once the installation is
   complete, the prompt will be returned.

   Some shells keep a cache of the commands that are available in the
   directories listed in the PATH environment variable, to speed up lookup
   operations for the executable file of these commands. Users of the tcsh
   shell should type rehash so that a newly installed command can be used
   without specifying its full path. Use hash -r instead for the sh shell.
   Refer to the documentation for the shell for more information.

   During installation, a working subdirectory is created which contains all
   the temporary files used during compilation. Removing this directory saves
   disk space and minimizes the chance of problems later when upgrading to
   the newer version of the port:

 # make clean
 ===>  Cleaning for lsof-88.d,8
 #

  Note:

   To save this extra step, instead use make install clean when compiling the
   port.

    4.5.1.1. Customizing Ports Installation

   Some ports provide build options which can be used to enable or disable
   application components, provide security options, or allow for other
   customizations. Examples include www/firefox, security/gpgme, and
   mail/sylpheed-claws. If the port depends upon other ports which have
   configurable options, it may pause several times for user interaction as
   the default behavior is to prompt the user to select options from a menu.
   To avoid this and do all of the configuration in one batch, run make
   config-recursive within the port skeleton. Then, run make install [clean]
   to compile and install the port.

  Tip:

   When using config-recursive, the list of ports to configure are gathered
   by the all-depends-list target. It is recommended to run make
   config-recursive until all dependent ports options have been defined, and
   ports options screens no longer appear, to be certain that all dependency
   options have been configured.

   There are several ways to revisit a port's build options menu in order to
   add, remove, or change these options after a port has been built. One
   method is to cd into the directory containing the port and type make
   config. Another option is to use make showconfig. Another option is to
   execute make rmconfig which will remove all selected options and allow you
   to start over. All of these options, and others, are explained in great
   detail in ports(7).

   The ports system uses fetch(1) to download the source files, which
   supports various environment variables. The FTP_PASSIVE_MODE, FTP_PROXY,
   and FTP_PASSWORD variables may need to be set if the FreeBSD system is
   behind a firewall or FTP/HTTP proxy. See fetch(3) for the complete list of
   supported variables.

   For users who cannot be connected to the Internet all the time, make fetch
   can be run within /usr/ports, to fetch all distfiles, or within a
   category, such as /usr/ports/net, or within the specific port skeleton.
   Note that if a port has any dependencies, running this command in a
   category or ports skeleton will not fetch the distfiles of ports from
   another category. Instead, use make fetch-recursive to also fetch the
   distfiles for all the dependencies of a port.

   In rare cases, such as when an organization has a local distfiles
   repository, the MASTER_SITES variable can be used to override the download
   locations specified in the Makefile. When using, specify the alternate
   location:

 # cd /usr/ports/directory
 # make MASTER_SITE_OVERRIDE= \
 ftp://ftp.organization.org/pub/FreeBSD/ports/distfiles/ fetch

   The WRKDIRPREFIX and PREFIX variables can override the default working and
   target directories. For example:

 # make WRKDIRPREFIX=/usr/home/example/ports install

   will compile the port in /usr/home/example/ports and install everything
   under /usr/local.

 # make PREFIX=/usr/home/example/local install

   will compile the port in /usr/ports and install it in
   /usr/home/example/local. And:

 # make WRKDIRPREFIX=../ports PREFIX=../local install

   will combine the two.

   These can also be set as environmental variables. Refer to the manual page
   for your shell for instructions on how to set an environmental variable.

  4.5.2. Removing Installed Ports

   Installed ports can be uninstalled using pkg delete. Examples for using
   this command can be found in the pkg-delete(8) manual page.

   Alternately, make deinstall can be run in the port's directory:

 # cd /usr/ports/sysutils/lsof
 # make deinstall
 ===>  Deinstalling for sysutils/lsof
 ===>   Deinstalling
 Deinstallation has been requested for the following 1 packages:

         lsof-4.88.d,8

 The deinstallation will free 229 kB
 [1/1] Deleting lsof-4.88.d,8... done

   It is recommended to read the messages as the port is uninstalled. If the
   port has any applications that depend upon it, this information will be
   displayed but the uninstallation will proceed. In such cases, it may be
   better to reinstall the application in order to prevent broken
   dependencies.

  4.5.3. Upgrading Ports

   Over time, newer versions of software become available in the Ports
   Collection. This section describes how to determine which software can be
   upgraded and how to perform the upgrade.

   To determine if newer versions of installed ports are available, ensure
   that the latest version of the ports tree is installed, using the updating
   command described in either Procedure 4.1, "Portsnap Method" or
   Procedure 4.2, "Subversion Method". On FreeBSD 10 and later, or if the
   system has been converted to pkg, the following command will list the
   installed ports which are out of date:

 # pkg version -l "<"

   For FreeBSD 9.X and lower, the following command will list the installed
   ports that are out of date:

 # pkg_version -l "<"

  Important:

   Before attempting an upgrade, read /usr/ports/UPDATING from the top of the
   file to the date closest to the last time ports were upgraded or the
   system was installed. This file describes various issues and additional
   steps users may encounter and need to perform when updating a port,
   including such things as file format changes, changes in locations of
   configuration files, or any incompatibilities with previous versions. Make
   note of any instructions which match any of the ports that need upgrading
   and follow these instructions when performing the upgrade.

    4.5.3.1. Tools to Upgrade and Manage Ports

   The Ports Collection contains several utilities to perform the actual
   upgrade. Each has its strengths and weaknesses.

   Historically, most installations used either Portmaster or Portupgrade.
   Synth is a newer alternative.

  Note:

   The choice of which tool is best for a particular system is up to the
   system administrator. It is recommended practice to back up your data
   before using any of these tools.

    4.5.3.2. Upgrading Ports Using Portmaster

   ports-mgmt/portmaster is a very small utility for upgrading installed
   ports. It is designed to use the tools installed with the FreeBSD base
   system without depending on other ports or databases. To install this
   utility as a port:

 # cd /usr/ports/ports-mgmt/portmaster
 # make install clean

   Portmaster defines four categories of ports:

     * Root port: has no dependencies and is not a dependency of any other
       ports.

     * Trunk port: has no dependencies, but other ports depend upon it.

     * Branch port: has dependencies and other ports depend upon it.

     * Leaf port: has dependencies but no other ports depend upon it.

   To list these categories and search for updates:

 # portmaster -L
 ===>>> Root ports (No dependencies, not depended on)
 ===>>> ispell-3.2.06_18
 ===>>> screen-4.0.3
         ===>>> New version available: screen-4.0.3_1
 ===>>> tcpflow-0.21_1
 ===>>> 7 root ports
 ...
 ===>>> Branch ports (Have dependencies, are depended on)
 ===>>> apache22-2.2.3
         ===>>> New version available: apache22-2.2.8
 ...
 ===>>> Leaf ports (Have dependencies, not depended on)
 ===>>> automake-1.9.6_2
 ===>>> bash-3.1.17
         ===>>> New version available: bash-3.2.33
 ...
 ===>>> 32 leaf ports

 ===>>> 137 total installed ports
         ===>>> 83 have new versions available

   This command is used to upgrade all outdated ports:

 # portmaster -a

  Note:

   By default, Portmaster makes a backup package before deleting the existing
   port. If the installation of the new version is successful, Portmaster
   deletes the backup. Using -b instructs Portmaster not to automatically
   delete the backup. Adding -i starts Portmaster in interactive mode,
   prompting for confirmation before upgrading each port. Many other options
   are available. Read through the manual page for portmaster(8) for details
   regarding their usage.

   If errors are encountered during the upgrade process, add -f to upgrade
   and rebuild all ports:

 # portmaster -af

   Portmaster can also be used to install new ports on the system, upgrading
   all dependencies before building and installing the new port. To use this
   function, specify the location of the port in the Ports Collection:

 # portmaster shells/bash

   More information about ports-mgmt/portmaster may be found in its
   pkg-descr.

    4.5.3.3. Upgrading Ports Using Portupgrade

   ports-mgmt/portupgrade is another utility that can be used to upgrade
   ports. It installs a suite of applications which can be used to manage
   ports. However, it is dependent upon Ruby. To install the port:

 # cd /usr/ports/ports-mgmt/portupgrade
 # make install clean

   Before performing an upgrade using this utility, it is recommended to scan
   the list of installed ports using pkgdb -F and to fix all the
   inconsistencies it reports.

   To upgrade all the outdated ports installed on the system, use portupgrade
   -a. Alternately, include -i to be asked for confirmation of every
   individual upgrade:

 # portupgrade -ai

   To upgrade only a specified application instead of all available ports,
   use portupgrade pkgname. It is very important to include -R to first
   upgrade all the ports required by the given application:

 # portupgrade -R firefox

   If -P is included, Portupgrade searches for available packages in the
   local directories listed in PKG_PATH. If none are available locally, it
   then fetches packages from a remote site. If packages can not be found
   locally or fetched remotely, Portupgrade will use ports. To avoid using
   ports entirely, specify -PP. This last set of options tells Portupgrade to
   abort if no packages are available:

 # portupgrade -PP gnome3

   To just fetch the port distfiles, or packages, if -P is specified, without
   building or installing anything, use -F. For further information on all of
   the available switches, refer to the manual page for portupgrade.

   More information about ports-mgmt/portupgrade may be found in its
   pkg-descr.

  4.5.4. Ports and Disk Space

   Using the Ports Collection will use up disk space over time. After
   building and installing a port, running make clean within the ports
   skeleton will clean up the temporary work directory. If Portmaster is used
   to install a port, it will automatically remove this directory unless -K
   is specified. If Portupgrade is installed, this command will remove all
   work directories found within the local copy of the Ports Collection:

 # portsclean -C

   In addition, outdated source distribution files accumulate in
   /usr/ports/distfiles over time. To use Portupgrade to delete all the
   distfiles that are no longer referenced by any ports:

 # portsclean -D

   Portupgrade can remove all distfiles not referenced by any port currently
   installed on the system:

 # portsclean -DD

   If Portmaster is installed, use:

 # portmaster --clean-distfiles

   By default, this command is interactive and prompts the user to confirm if
   a distfile should be deleted.

   In addition to these commands, ports-mgmt/pkg_cutleaves automates the task
   of removing installed ports that are no longer needed.

4.6. Building Packages with Poudriere

   Poudriere is a BSD-licensed utility for creating and testing FreeBSD
   packages. It uses FreeBSD jails to set up isolated compilation
   environments. These jails can be used to build packages for versions of
   FreeBSD that are different from the system on which it is installed, and
   also to build packages for i386 if the host is an amd64 system. Once the
   packages are built, they are in a layout identical to the official
   mirrors. These packages are usable by pkg(8) and other package management
   tools.

   Poudriere is installed using the ports-mgmt/poudriere package or port. The
   installation includes a sample configuration file
   /usr/local/etc/poudriere.conf.sample. Copy this file to
   /usr/local/etc/poudriere.conf. Edit the copied file to suit the local
   configuration.

   While ZFS is not required on the system running poudriere, it is
   beneficial. When ZFS is used, ZPOOL must be specified in
   /usr/local/etc/poudriere.conf and FREEBSD_HOST should be set to a nearby
   mirror. Defining CCACHE_DIR enables the use of devel/ccache to cache
   compilation and reduce build times for frequently-compiled code. It may be
   convenient to put poudriere datasets in an isolated tree mounted at
   /poudriere. Defaults for the other configuration values are adequate.

   The number of processor cores detected is used to define how many builds
   will run in parallel. Supply enough virtual memory, either with RAM or
   swap space. If virtual memory runs out, the compilation jails will stop
   and be torn down, resulting in weird error messages.

  4.6.1. Initialize Jails and Port Trees

   After configuration, initialize poudriere so that it installs a jail with
   the required FreeBSD tree and a ports tree. Specify a name for the jail
   using -j and the FreeBSD version with -v. On systems running
   FreeBSD/amd64, the architecture can be set with -a to either i386 or
   amd64. The default is the architecture shown by uname.

 # poudriere jail -c -j 11amd64 -v 11.4-RELEASE
 [00:00:00] Creating 11amd64 fs at /poudriere/jails/11amd64... done
 [00:00:00] Using pre-distributed MANIFEST for FreeBSD 11.4-RELEASE amd64
 [00:00:00] Fetching base for FreeBSD 11.4-RELEASE amd64
 /poudriere/jails/11amd64/fromftp/base.txz              125 MB 4110 kBps    31s
 [00:00:33] Extracting base... done
 [00:00:54] Fetching src for FreeBSD 11.4-RELEASE amd64
 /poudriere/jails/11amd64/fromftp/src.txz               154 MB 4178 kBps    38s
 [00:01:33] Extracting src... done
 [00:02:31] Fetching lib32 for FreeBSD 11.4-RELEASE amd64
 /poudriere/jails/11amd64/fromftp/lib32.txz              24 MB 3969 kBps    06s
 [00:02:38] Extracting lib32... done
 [00:02:42] Cleaning up... done
 [00:02:42] Recording filesystem state for clean... done
 [00:02:42] Upgrading using ftp
 /etc/resolv.conf -> /poudriere/jails/11amd64/etc/resolv.conf
 Looking up update.FreeBSD.org mirrors... 3 mirrors found.
 Fetching public key from update4.freebsd.org... done.
 Fetching metadata signature for 11.4-RELEASE from update4.freebsd.org... done.
 Fetching metadata index... done.
 Fetching 2 metadata files... done.
 Inspecting system... done.
 Preparing to download files... done.
 Fetching 124 patches.....10....20....30....40....50....60....70....80....90....100....110....120.. done.
 Applying patches... done.
 Fetching 6 files... done.
 The following files will be added as part of updating to
 11.4-RELEASE-p1:
 /usr/src/contrib/unbound/.github
 /usr/src/contrib/unbound/.github/FUNDING.yml
 /usr/src/contrib/unbound/contrib/drop2rpz
 /usr/src/contrib/unbound/contrib/unbound_portable.service.in
 /usr/src/contrib/unbound/services/rpz.c
 /usr/src/contrib/unbound/services/rpz.h
 /usr/src/lib/libc/tests/gen/spawnp_enoexec.sh
 The following files will be updated as part of updating to
 11.4-RELEASE-p1:
 [...]
 Installing updates...Scanning //usr/share/certs/blacklisted for certificates...
 Scanning //usr/share/certs/trusted for certificates...
  done.
 11.4-RELEASE-p1
 [00:04:06] Recording filesystem state for clean... done
 [00:04:07] Jail 11amd64 11.4-RELEASE-p1 amd64 is ready to be used

 # poudriere ports -c -p local -m svn+https
 [00:00:00] Creating local fs at /poudriere/ports/local... done
 [00:00:00] Checking out the ports tree... done

   On a single computer, poudriere can build ports with multiple
   configurations, in multiple jails, and from different port trees. Custom
   configurations for these combinations are called sets. See the
   CUSTOMIZATION section of poudriere(8) for details after
   ports-mgmt/poudriere or ports-mgmt/poudriere-devel is installed.

   The basic configuration shown here puts a single jail-, port-, and
   set-specific make.conf in /usr/local/etc/poudriere.d. The filename in this
   example is created by combining the jail name, port name, and set name:
   11amd64-local-workstation-make.conf. The system make.conf and this new
   file are combined at build time to create the make.conf used by the build
   jail.

   Packages to be built are entered in 11amd64-local-workstation-pkglist:

 editors/emacs
 devel/git
 ports-mgmt/pkg
 ...

   Options and dependencies for the specified ports are configured:

 # poudriere options -j 11amd64 -p local -z workstation -f 11amd64-local-workstation-pkglist

   Finally, packages are built and a package repository is created:

 # poudriere bulk -j 11amd64 -p local -z workstation -f 11amd64-local-workstation-pkglist

   While running, pressing Ctrl+t displays the current state of the build.
   Poudriere also builds files in /poudriere/logs/bulk/jailname that can be
   used with a web server to display build information.

   After completion, the new packages are now available for installation from
   the poudriere repository.

   For more information on using poudriere, see poudriere(8) and the main web
   site, https://github.com/freebsd/poudriere/wiki.

  4.6.2. Configuring pkg Clients to Use a Poudriere Repository

   While it is possible to use both a custom repository along side of the
   official repository, sometimes it is useful to disable the official
   repository. This is done by creating a configuration file that overrides
   and disables the official configuration file. Create
   /usr/local/etc/pkg/repos/FreeBSD.conf that contains the following:

 FreeBSD: {
         enabled: no
 }

   Usually it is easiest to serve a poudriere repository to the client
   machines via HTTP. Set up a webserver to serve up the package directory,
   for instance: /usr/local/poudriere/data/packages/11amd64, where 11amd64 is
   the name of the build.

   If the URL to the package repository is: http://pkg.example.com/11amd64,
   then the repository configuration file in
   /usr/local/etc/pkg/repos/custom.conf would look like:

 custom: {
         url: "http://pkg.example.com/11amd64",
         enabled: yes,
 }

4.7. Post-Installation Considerations

   Regardless of whether the software was installed from a binary package or
   port, most third-party applications require some level of configuration
   after installation. The following commands and locations can be used to
   help determine what was installed with the application.

     * Most applications install at least one default configuration file in
       /usr/local/etc. In cases where an application has a large number of
       configuration files, a subdirectory will be created to hold them.
       Often, sample configuration files are installed which end with a
       suffix such as .sample. The configuration files should be reviewed and
       possibly edited to meet the system's needs. To edit a sample file,
       first copy it without the .sample extension.

     * Applications which provide documentation will install it into
       /usr/local/share/doc and many applications also install manual pages.
       This documentation should be consulted before continuing.

     * Some applications run services which must be added to /etc/rc.conf
       before starting the application. These applications usually install a
       startup script in /usr/local/etc/rc.d. See Starting Services for more
       information.

  Note:

       By design, applications do not run their startup script upon
       installation, nor do they run their stop script upon deinstallation or
       upgrade. This decision is left to the individual system administrator.

     * Users of csh(1) should run rehash to rebuild the known binary list in
       the shells PATH.

     * Use pkg info to determine which files, man pages, and binaries were
       installed with the application.

4.8. Dealing with Broken Ports

   When a port does not build or install, try the following:

    1. Search to see if there is a fix pending for the port in the Problem
       Report database. If so, implementing the proposed fix may fix the
       issue.

    2. Ask the maintainer of the port for help. Type make maintainer in the
       ports skeleton or read the port's Makefile to find the maintainer's
       email address. Remember to include the $FreeBSD: line from the port's
       Makefile and the output leading up to the error in the email to the
       maintainer.

  Note:

       Some ports are not maintained by an individual but instead by a group
       maintainer represented by a mailing list. Many, but not all, of these
       addresses look like <freebsd-listname@FreeBSD.org>. Please take this
       into account when sending an email.

       In particular, ports maintained by <ports@FreeBSD.org> are not
       maintained by a specific individual. Instead, any fixes and support
       come from the general community who subscribe to that mailing list.
       More volunteers are always needed!

       If there is no response to the email, use Bugzilla to submit a bug
       report using the instructions in Writing FreeBSD Problem Reports.

    3. Fix it! The Porter's Handbook includes detailed information on the
       ports infrastructure so that you can fix the occasional broken port or
       even submit your own!

    4. Install the package instead of the port using the instructions in
       Section 4.4, "Using pkg for Binary Package Management".

Chapter 5. The X Window System

   Table of Contents

   5.1. Synopsis

   5.2. Terminology

   5.3. Installing Xorg

   5.4. Xorg Configuration

   5.5. Using Fonts in Xorg

   5.6. The X Display Manager

   5.7. Desktop Environments

   5.8. Installing Compiz Fusion

   5.9. Troubleshooting

5.1. Synopsis

   An installation of FreeBSD using bsdinstall does not automatically install
   a graphical user interface. This chapter describes how to install and
   configure Xorg, which provides the open source X Window System used to
   provide a graphical environment. It then describes how to find and install
   a desktop environment or window manager.

  Note:

   Users who prefer an installation method that automatically configures the
   Xorg should refer to GhostBSD, MidnightBSD or NomadBSD.

   For more information on the video hardware that Xorg supports, refer to
   the x.org website.

   After reading this chapter, you will know:

     * The various components of the X Window System, and how they
       interoperate.

     * How to install and configure Xorg.

     * How to install and configure several window managers and desktop
       environments.

     * How to use TrueType(R) fonts in Xorg.

     * How to set up your system for graphical logins (XDM).

   Before reading this chapter, you should:

     * Know how to install additional third-party software as described in
       Chapter 4, Installing Applications: Packages and Ports.

5.2. Terminology

   While it is not necessary to understand all of the details of the various
   components in the X Window System and how they interact, some basic
   knowledge of these components can be useful.

   X server

           X was designed from the beginning to be network-centric, and
           adopts a "client-server" model. In this model, the "X server" runs
           on the computer that has the keyboard, monitor, and mouse
           attached. The server's responsibility includes tasks such as
           managing the display, handling input from the keyboard and mouse,
           and handling input or output from other devices such as a tablet
           or a video projector. This confuses some people, because the X
           terminology is exactly backward to what they expect. They expect
           the "X server" to be the big powerful machine down the hall, and
           the "X client" to be the machine on their desk.

   X client

           Each X application, such as XTerm or Firefox, is a "client". A
           client sends messages to the server such as "Please draw a window
           at these coordinates", and the server sends back messages such as
           "The user just clicked on the OK button".

           In a home or small office environment, the X server and the X
           clients commonly run on the same computer. It is also possible to
           run the X server on a less powerful computer and to run the X
           applications on a more powerful system. In this scenario, the
           communication between the X client and server takes place over the
           network.

   window manager

           X does not dictate what windows should look like on-screen, how to
           move them around with the mouse, which keystrokes should be used
           to move between windows, what the title bars on each window should
           look like, whether or not they have close buttons on them, and so
           on. Instead, X delegates this responsibility to a separate window
           manager application. There are dozens of window managers
           available. Each window manager provides a different look and feel:
           some support virtual desktops, some allow customized keystrokes to
           manage the desktop, some have a "Start" button, and some are
           themeable, allowing a complete change of the desktop's
           look-and-feel. Window managers are available in the x11-wm
           category of the Ports Collection.

           Each window manager uses a different configuration mechanism. Some
           expect configuration file written by hand while others provide
           graphical tools for most configuration tasks.

   desktop environment

           KDE and GNOME are considered to be desktop environments as they
           include an entire suite of applications for performing common
           desktop tasks. These may include office suites, web browsers, and
           games.

   focus policy

           The window manager is responsible for the mouse focus policy. This
           policy provides some means for choosing which window is actively
           receiving keystrokes and it should also visibly indicate which
           window is currently active.

           One focus policy is called "click-to-focus". In this model, a
           window becomes active upon receiving a mouse click. In the
           "focus-follows-mouse" policy, the window that is under the mouse
           pointer has focus and the focus is changed by pointing at another
           window. If the mouse is over the root window, then this window is
           focused. In the "sloppy-focus" model, if the mouse is moved over
           the root window, the most recently used window still has the
           focus. With sloppy-focus, focus is only changed when the cursor
           enters a new window, and not when exiting the current window. In
           the "click-to-focus" policy, the active window is selected by
           mouse click. The window may then be raised and appear in front of
           all other windows. All keystrokes will now be directed to this
           window, even if the cursor is moved to another window.

           Different window managers support different focus models. All of
           them support click-to-focus, and the majority of them also support
           other policies. Consult the documentation for the window manager
           to determine which focus models are available.

   widgets

           Widget is a term for all of the items in the user interface that
           can be clicked or manipulated in some way. This includes buttons,
           check boxes, radio buttons, icons, and lists. A widget toolkit is
           a set of widgets used to create graphical applications. There are
           several popular widget toolkits, including Qt, used by KDE, and
           GTK+, used by GNOME. As a result, applications will have a
           different look and feel, depending upon which widget toolkit was
           used to create the application.

5.3. Installing Xorg

   On FreeBSD, Xorg can be installed as a package or port.

   The binary package can be installed quickly but with fewer options for
   customization:

 # pkg install xorg

   To build and install from the Ports Collection:

 # cd /usr/ports/x11/xorg
 # make install clean

   Either of these installations results in the complete Xorg system being
   installed. Binary packages are the best option for most users.

   A smaller version of the X system suitable for experienced users is
   available in x11/xorg-minimal. Most of the documents, libraries, and
   applications will not be installed. Some applications require these
   additional components to function.

5.4. Xorg Configuration

   Originally contributed by Warren Block.

  5.4.1. Quick Start

   Xorg supports most common video cards, keyboards, and pointing devices.

  Tip:

   Video cards, monitors, and input devices are automatically detected and do
   not require any manual configuration. Do not create xorg.conf or run a
   -configure step unless automatic configuration fails.

    1. If Xorg has been used on this computer before, move or remove any
       existing configuration files:

 # mv /etc/X11/xorg.conf ~/xorg.conf.etc
 # mv /usr/local/etc/X11/xorg.conf ~/xorg.conf.localetc

    2. Add the user who will run Xorg to the video or wheel group to enable
       3D acceleration when available. To add user jru to whichever group is
       available:

 # pw groupmod video -m jru || pw groupmod wheel -m jru

    3. The twm window manager is included by default. It is started when Xorg
       starts:

 % startx

    4. On some older versions of FreeBSD, the system console must be set to
       vt(4) before switching back to the text console will work properly.
       See Section 5.4.3, "Kernel Mode Setting (KMS)".

  5.4.2. User Group for Accelerated Video

   Access to /dev/dri is needed to allow 3D acceleration on video cards. It
   is usually simplest to add the user who will be running X to either the
   video or wheel group. Here, pw(8) is used to add user slurms to the video
   group, or to the wheel group if there is no video group:

 # pw groupmod video -m slurms || pw groupmod wheel -m slurms

  5.4.3. Kernel Mode Setting (KMS)

   When the computer switches from displaying the console to a higher screen
   resolution for X, it must set the video output mode. Recent versions of
   Xorg use a system inside the kernel to do these mode changes more
   efficiently. Older versions of FreeBSD use sc(4), which is not aware of
   the KMS system. The end result is that after closing X, the system console
   is blank, even though it is still working. The newer vt(4) console avoids
   this problem.

   Add this line to /boot/loader.conf to enable vt(4):

 kern.vty=vt

  5.4.4. Configuration Files

   Manual configuration is usually not necessary. Please do not manually
   create configuration files unless autoconfiguration does not work.

    5.4.4.1. Directory

   Xorg looks in several directories for configuration files.
   /usr/local/etc/X11/ is the recommended directory for these files on
   FreeBSD. Using this directory helps keep application files separate from
   operating system files.

   Storing configuration files in the legacy /etc/X11/ still works. However,
   this mixes application files with the base FreeBSD files and is not
   recommended.

    5.4.4.2. Single or Multiple Files

   It is easier to use multiple files that each configure a specific setting
   than the traditional single xorg.conf. These files are stored in the
   xorg.conf.d/ subdirectory of the main configuration file directory. The
   full path is typically /usr/local/etc/X11/xorg.conf.d/.

   Examples of these files are shown later in this section.

   The traditional single xorg.conf still works, but is neither as clear nor
   as flexible as multiple files in the xorg.conf.d/ subdirectory.

  5.4.5. Video Cards

   Because of changes made in recent versions of FreeBSD, it is now possible
   to use graphics drivers provided by the Ports framework or as packages. As
   such, users can use one of the following drivers available from
   graphics/drm-kmod.

   Intel KMS driver, Radeon KMS driver, AMD KMS driver

           2D and 3D acceleration is supported on most Intel KMS driver
           graphics cards provided by Intel(R).

           Driver name: i915kms

           2D and 3D acceleration is supported on most older Radeon KMS
           driver graphics cards provided by AMD(R).

           Driver name: radeonkms

           2D and 3D acceleration is supported on most newer AMD KMS driver
           graphics cards provided by AMD(R)..

           Driver name: amdgpu

           For reference, please see
           https://en.wikipedia.org/wiki/List_of_Intel_graphics_processing_units
           or
           https://en.wikipedia.org/wiki/List_of_AMD_graphics_processing_units
           for a list of supported GPUs.

   Intel(R)

           3D acceleration is supported on most Intel(R) graphics up to Ivy
           Bridge (HD Graphics 2500, 4000, and P4000), including Iron Lake
           (HD Graphics) and Sandy Bridge (HD Graphics 2000).

           Driver name: intel

           For reference, see
           https://en.wikipedia.org/wiki/List_of_Intel_graphics_processing_units.

   AMD(R) Radeon

           2D and 3D acceleration is supported on Radeon cards up to and
           including the HD6000 series.

           Driver name: radeon

           For reference, see
           https://en.wikipedia.org/wiki/List_of_AMD_graphics_processing_units.

   NVIDIA

           Several NVIDIA drivers are available in the x11 category of the
           Ports Collection. Install the driver that matches the video card.

           For reference, see
           https://en.wikipedia.org/wiki/List_of_Nvidia_graphics_processing_units.

   Hybrid Combination Graphics

           Some notebook computers add additional graphics processing units
           to those built into the chipset or processor. Optimus combines
           Intel(R) and NVIDIA hardware. Switchable Graphics or Hybrid
           Graphics are a combination of an Intel(R) or AMD(R) processor and
           an AMD(R) Radeon GPU.

           Implementations of these hybrid graphics systems vary, and Xorg on
           FreeBSD is not able to drive all versions of them.

           Some computers provide a BIOS option to disable one of the
           graphics adapters or select a discrete mode which can be used with
           one of the standard video card drivers. For example, it is
           sometimes possible to disable the NVIDIA GPU in an Optimus system.
           The Intel(R) video can then be used with an Intel(R) driver.

           BIOS settings depend on the model of computer. In some situations,
           both GPUs can be left enabled, but creating a configuration file
           that only uses the main GPU in the Device section is enough to
           make such a system functional.

   Other Video Cards

           Drivers for some less-common video cards can be found in the
           x11-drivers directory of the Ports Collection.

           Cards that are not supported by a specific driver might still be
           usable with the x11-drivers/xf86-video-vesa driver. This driver is
           installed by x11/xorg. It can also be installed manually as
           x11-drivers/xf86-video-vesa. Xorg attempts to use this driver when
           a specific driver is not found for the video card.

           x11-drivers/xf86-video-scfb is a similar nonspecialized video
           driver that works on many UEFI and ARM(R) computers.

   Setting the Video Driver in a File

           To set the Intel(R) driver in a configuration file:

           Example 5.1. Select Intel(R) Video Driver in a File

           /usr/local/etc/X11/xorg.conf.d/driver-intel.conf

 Section "Device"
         Identifier "Card0"
         Driver     "intel"
         # BusID    "PCI:1:0:0"
 EndSection

           If more than one video card is present, the BusID identifier can
           be uncommented and set to select the desired card. A list of video
           card bus IDs can be displayed with pciconf -lv | grep -B3 display.

           To set the Radeon driver in a configuration file:

           Example 5.2. Select Radeon Video Driver in a File

           /usr/local/etc/X11/xorg.conf.d/driver-radeon.conf

 Section "Device"
         Identifier "Card0"
         Driver     "radeon"
 EndSection

           To set the VESA driver in a configuration file:

           Example 5.3. Select VESA Video Driver in a File

           /usr/local/etc/X11/xorg.conf.d/driver-vesa.conf

 Section "Device"
         Identifier "Card0"
         Driver     "vesa"
 EndSection

           To set the scfb driver for use with a UEFI or ARM(R) computer:

           Example 5.4. Select scfb Video Driver in a File

           /usr/local/etc/X11/xorg.conf.d/driver-scfb.conf

 Section "Device"
         Identifier "Card0"
         Driver     "scfb"
 EndSection

  5.4.6. Monitors

   Almost all monitors support the Extended Display Identification Data
   standard (EDID). Xorg uses EDID to communicate with the monitor and detect
   the supported resolutions and refresh rates. Then it selects the most
   appropriate combination of settings to use with that monitor.

   Other resolutions supported by the monitor can be chosen by setting the
   desired resolution in configuration files, or after the X server has been
   started with xrandr(1).

   Using xrandr(1)

           Run xrandr(1) without any parameters to see a list of video
           outputs and detected monitor modes:

 % xrandr
 Screen 0: minimum 320 x 200, current 3000 x 1920, maximum 8192 x 8192
 DVI-0 connected primary 1920x1200+1080+0 (normal left inverted right x axis y axis) 495mm x 310mm
    1920x1200     59.95*+
    1600x1200     60.00
    1280x1024     85.02    75.02    60.02
    1280x960      60.00
    1152x864      75.00
    1024x768      85.00    75.08    70.07    60.00
    832x624       74.55
    800x600       75.00    60.32
    640x480       75.00    60.00
    720x400       70.08
 DisplayPort-0 disconnected (normal left inverted right x axis y axis)
 HDMI-0 disconnected (normal left inverted right x axis y axis)

           This shows that the DVI-0 output is being used to display a screen
           resolution of 1920x1200 pixels at a refresh rate of about 60 Hz.
           Monitors are not attached to the DisplayPort-0 and HDMI-0
           connectors.

           Any of the other display modes can be selected with xrandr(1). For
           example, to switch to 1280x1024 at 60 Hz:

 % xrandr --mode 1280x1024 --rate 60

           A common task is using the external video output on a notebook
           computer for a video projector.

           The type and quantity of output connectors varies between devices,
           and the name given to each output varies from driver to driver.
           What one driver calls HDMI-1, another might call HDMI1. So the
           first step is to run xrandr(1) to list all the available outputs:

 % xrandr
 Screen 0: minimum 320 x 200, current 1366 x 768, maximum 8192 x 8192
 LVDS1 connected 1366x768+0+0 (normal left inverted right x axis y axis) 344mm x 193mm
    1366x768      60.04*+
    1024x768      60.00
    800x600       60.32    56.25
    640x480       59.94
 VGA1 connected (normal left inverted right x axis y axis)
    1280x1024     60.02 +  75.02
    1280x960      60.00
    1152x864      75.00
    1024x768      75.08    70.07    60.00
    832x624       74.55
    800x600       72.19    75.00    60.32    56.25
    640x480       75.00    72.81    66.67    60.00
    720x400       70.08
 HDMI1 disconnected (normal left inverted right x axis y axis)
 DP1 disconnected (normal left inverted right x axis y axis)

           Four outputs were found: the built-in panel LVDS1, and external
           VGA1, HDMI1, and DP1 connectors.

           The projector has been connected to the VGA1 output. xrandr(1) is
           now used to set that output to the native resolution of the
           projector and add the additional space to the right side of the
           desktop:

 % xrandr --output VGA1 --auto --right-of LVDS1

           --auto chooses the resolution and refresh rate detected by EDID.
           If the resolution is not correctly detected, a fixed value can be
           given with --mode instead of the --auto statement. For example,
           most projectors can be used with a 1024x768 resolution, which is
           set with --mode 1024x768.

           xrandr(1) is often run from .xinitrc to set the appropriate mode
           when X starts.

   Setting Monitor Resolution in a File

           To set a screen resolution of 1024x768 in a configuration file:

           Example 5.5. Set Screen Resolution in a File

           /usr/local/etc/X11/xorg.conf.d/screen-resolution.conf

 Section "Screen"
         Identifier "Screen0"
         Device     "Card0"
         SubSection "Display"
         Modes      "1024x768"
         EndSubSection
 EndSection

           The few monitors that do not have EDID can be configured by
           setting HorizSync and VertRefresh to the range of frequencies
           supported by the monitor.

           Example 5.6. Manually Setting Monitor Frequencies

           /usr/local/etc/X11/xorg.conf.d/monitor0-freq.conf

 Section "Monitor"
         Identifier   "Monitor0"
         HorizSync    30-83   # kHz
         VertRefresh  50-76   # Hz
 EndSection

  5.4.7. Input Devices

    5.4.7.1. Keyboards

   Keyboard Layout

           The standardized location of keys on a keyboard is called a
           layout. Layouts and other adjustable parameters are listed in
           xkeyboard-config(7).

           A United States layout is the default. To select an alternate
           layout, set the XkbLayout and XkbVariant options in an InputClass.
           This will be applied to all input devices that match the class.

           This example selects a French keyboard layout.

           Example 5.7. Setting a Keyboard Layout

           /usr/local/etc/X11/xorg.conf.d/keyboard-fr.conf

 Section "InputClass"
         Identifier      "KeyboardDefaults"
         MatchIsKeyboard "on"
         Option          "XkbLayout" "fr"
 EndSection

           Example 5.8. Setting Multiple Keyboard Layouts

           Set United States, Spanish, and Ukrainian keyboard layouts. Cycle
           through these layouts by pressing Alt+Shift. x11/xxkb or x11/sbxkb
           can be used for improved layout switching control and current
           layout indicators.

           /usr/local/etc/X11/xorg.conf.d/kbd-layout-multi.conf

 Section "InputClass"
         Identifier      "All Keyboards"
         MatchIsKeyboard "yes"
         Option          "XkbLayout" "us, es, ua"
 EndSection

   Closing Xorg From the Keyboard

           X can be closed with a combination of keys. By default, that key
           combination is not set because it conflicts with keyboard commands
           for some applications. Enabling this option requires changes to
           the keyboard InputDevice section:

           Example 5.9. Enabling Keyboard Exit from X

           /usr/local/etc/X11/xorg.conf.d/keyboard-zap.conf

 Section "InputClass"
         Identifier      "KeyboardDefaults"
         MatchIsKeyboard "on"
         Option          "XkbOptions" "terminate:ctrl_alt_bksp"
 EndSection

    5.4.7.2. Mice and Pointing Devices

  Important:

   If using xorg-server 1.20.8 or later under FreeBSD 12.1 and not using
   moused(8), add kern.evdev.rcpt_mask=12 to /etc/sysctl.conf.

   Many mouse parameters can be adjusted with configuration options. See
   mousedrv(4) for a full list.

   Mouse Buttons

           The number of buttons on a mouse can be set in the mouse
           InputDevice section of xorg.conf. To set the number of buttons to
           7:

           Example 5.10. Setting the Number of Mouse Buttons

           /usr/local/etc/X11/xorg.conf.d/mouse0-buttons.conf

 Section "InputDevice"
         Identifier  "Mouse0"
         Option      "Buttons" "7"
 EndSection

  5.4.8. Manual Configuration

   In some cases, Xorg autoconfiguration does not work with particular
   hardware, or a different configuration is desired. For these cases, a
   custom configuration file can be created.

  Warning:

   Do not create manual configuration files unless required. Unnecessary
   manual configuration can prevent proper operation.

   A configuration file can be generated by Xorg based on the detected
   hardware. This file is often a useful starting point for custom
   configurations.

   Generating an xorg.conf:

 # Xorg -configure

   The configuration file is saved to /root/xorg.conf.new. Make any changes
   desired, then test that file (using -retro so there is a visible
   background) with:

 # Xorg -retro -config /root/xorg.conf.new

   After the new configuration has been adjusted and tested, it can be split
   into smaller files in the normal location,
   /usr/local/etc/X11/xorg.conf.d/.

5.5. Using Fonts in Xorg

  5.5.1. Type1 Fonts

   The default fonts that ship with Xorg are less than ideal for typical
   desktop publishing applications. Large presentation fonts show up jagged
   and unprofessional looking, and small fonts are almost completely
   unintelligible. However, there are several free, high quality Type1
   (PostScript(R)) fonts available which can be readily used with Xorg. For
   instance, the URW font collection (x11-fonts/urwfonts) includes high
   quality versions of standard type1 fonts (Times Roman(R), Helvetica(R),
   Palatino(R) and others). The Freefonts collection (x11-fonts/freefonts)
   includes many more fonts, but most of them are intended for use in
   graphics software such as the Gimp, and are not complete enough to serve
   as screen fonts. In addition, Xorg can be configured to use TrueType(R)
   fonts with a minimum of effort. For more details on this, see the X(7)
   manual page or Section 5.5.2, "TrueType(R) Fonts".

   To install the above Type1 font collections from binary packages, run the
   following commands:

 # pkg install urwfonts

   Alternatively, to build from the Ports Collection, run the following
   commands:

 # cd /usr/ports/x11-fonts/urwfonts
 # make install clean

   And likewise with the freefont or other collections. To have the X server
   detect these fonts, add an appropriate line to the X server configuration
   file (/etc/X11/xorg.conf), which reads:

 FontPath "/usr/local/share/fonts/urwfonts/"

   Alternatively, at the command line in the X session run:

 % xset fp+ /usr/local/share/fonts/urwfonts
 % xset fp rehash

   This will work but will be lost when the X session is closed, unless it is
   added to the startup file (~/.xinitrc for a normal startx session, or
   ~/.xsession when logging in through a graphical login manager like XDM). A
   third way is to use the new /usr/local/etc/fonts/local.conf as
   demonstrated in Section 5.5.3, "Anti-Aliased Fonts".

  5.5.2. TrueType(R) Fonts

   Xorg has built in support for rendering TrueType(R) fonts. There are two
   different modules that can enable this functionality. The freetype module
   is used in this example because it is more consistent with the other font
   rendering back-ends. To enable the freetype module just add the following
   line to the "Module" section of /etc/X11/xorg.conf.

 Load  "freetype"

   Now make a directory for the TrueType(R) fonts (for example,
   /usr/local/share/fonts/TrueType) and copy all of the TrueType(R) fonts
   into this directory. Keep in mind that TrueType(R) fonts cannot be
   directly taken from an Apple(R) Mac(R); they must be in
   UNIX(R)/MS-DOS(R)/Windows(R) format for use by Xorg. Once the files have
   been copied into this directory, use mkfontscale to create a fonts.dir, so
   that the X font renderer knows that these new files have been installed.
   mkfontscale can be installed as a package:

 # pkg install mkfontscale

   Then create an index of X font files in a directory:

 # cd /usr/local/share/fonts/TrueType
 # mkfontscale

   Now add the TrueType(R) directory to the font path. This is just the same
   as described in Section 5.5.1, "Type1 Fonts":

 % xset fp+ /usr/local/share/fonts/TrueType
 % xset fp rehash

   or add a FontPath line to xorg.conf.

   Now Gimp, LibreOffice, and all of the other X applications should now
   recognize the installed TrueType(R) fonts. Extremely small fonts (as with
   text in a high resolution display on a web page) and extremely large fonts
   (within LibreOffice) will look much better now.

  5.5.3. Anti-Aliased Fonts

   All fonts in Xorg that are found in /usr/local/share/fonts/ and ~/.fonts/
   are automatically made available for anti-aliasing to Xft-aware
   applications. Most recent applications are Xft-aware, including KDE,
   GNOME, and Firefox.

   To control which fonts are anti-aliased, or to configure anti-aliasing
   properties, create (or edit, if it already exists) the file
   /usr/local/etc/fonts/local.conf. Several advanced features of the Xft font
   system can be tuned using this file; this section describes only some
   simple possibilities. For more details, please see fonts-conf(5).

   This file must be in XML format. Pay careful attention to case, and make
   sure all tags are properly closed. The file begins with the usual XML
   header followed by a DOCTYPE definition, and then the <fontconfig> tag:

 <?xml version="1.0"?>
       <!DOCTYPE fontconfig SYSTEM "fonts.dtd">
       <fontconfig>

   As previously stated, all fonts in /usr/local/share/fonts/ as well as
   ~/.fonts/ are already made available to Xft-aware applications. To add
   another directory outside of these two directory trees, add a line like
   this to /usr/local/etc/fonts/local.conf:

 <dir>/path/to/my/fonts</dir>

   After adding new fonts, and especially new font directories, rebuild the
   font caches:

 # fc-cache -f

   Anti-aliasing makes borders slightly fuzzy, which makes very small text
   more readable and removes "staircases" from large text, but can cause
   eyestrain if applied to normal text. To exclude font sizes smaller than 14
   point from anti-aliasing, include these lines:

         <match target="font">
             <test name="size" compare="less">
                 <double>14</double>
             </test>
             <edit name="antialias" mode="assign">
                 <bool>false</bool>
             </edit>
         </match>
         <match target="font">
             <test name="pixelsize" compare="less" qual="any">
                 <double>14</double>
             </test>
             <edit mode="assign" name="antialias">
                 <bool>false</bool>
             </edit>
         </match>

   Spacing for some monospaced fonts might also be inappropriate with
   anti-aliasing. This seems to be an issue with KDE, in particular. One
   possible fix is to force the spacing for such fonts to be 100. Add these
   lines:

         <match target="pattern" name="family">
            <test qual="any" name="family">
                <string>fixed</string>
            </test>
            <edit name="family" mode="assign">
                <string>mono</string>
            </edit>
         </match>
         <match target="pattern" name="family">
             <test qual="any" name="family">
                 <string>console</string>
             </test>
             <edit name="family" mode="assign">
                 <string>mono</string>
             </edit>
         </match>

   (this aliases the other common names for fixed fonts as "mono"), and then
   add:

          <match target="pattern" name="family">
              <test qual="any" name="family">
                  <string>mono</string>
              </test>
              <edit name="spacing" mode="assign">
                  <int>100</int>
              </edit>
          </match>     

   Certain fonts, such as Helvetica, may have a problem when anti-aliased.
   Usually this manifests itself as a font that seems cut in half vertically.
   At worst, it may cause applications to crash. To avoid this, consider
   adding the following to local.conf:

          <match target="pattern" name="family">
              <test qual="any" name="family">
                  <string>Helvetica</string>
              </test>
              <edit name="family" mode="assign">
                  <string>sans-serif</string>
              </edit>
          </match>       

   After editing local.conf, make certain to end the file with the
   </fontconfig> tag. Not doing this will cause changes to be ignored.

   Users can add personalized settings by creating their own
   ~/.config/fontconfig/fonts.conf. This file uses the same XML format
   described above.

   One last point: with an LCD screen, sub-pixel sampling may be desired.
   This basically treats the (horizontally separated) red, green and blue
   components separately to improve the horizontal resolution; the results
   can be dramatic. To enable this, add the line somewhere in local.conf:

          <match target="font">
              <test qual="all" name="rgba">
                  <const>unknown</const>
              </test>
              <edit name="rgba" mode="assign">
                  <const>rgb</const>
              </edit>
          </match>

  Note:

   Depending on the sort of display, rgb may need to be changed to bgr, vrgb
   or vbgr: experiment and see which works best.

5.6. The X Display Manager

   Originally contributed by Seth Kingsley.

   Xorg provides an X Display Manager, XDM, which can be used for login
   session management. XDM provides a graphical interface for choosing which
   display server to connect to and for entering authorization information
   such as a login and password combination.

   This section demonstrates how to configure the X Display Manager on
   FreeBSD. Some desktop environments provide their own graphical login
   manager. Refer to Section 5.7.1, "GNOME" for instructions on how to
   configure the GNOME Display Manager and Section 5.7.2, "KDE" for
   instructions on how to configure the KDE Display Manager.

  5.6.1. Configuring XDM

   To install XDM, use the x11/xdm package or port. Once installed, XDM can
   be configured to run when the machine boots up by editing this entry in
   /etc/ttys:

 ttyv8   "/usr/local/bin/xdm -nodaemon"  xterm   off secure

   Change the off to on and save the edit. The ttyv8 in this entry indicates
   that XDM will run on the ninth virtual terminal.

   The XDM configuration directory is located in /usr/local/etc/X11/xdm. This
   directory contains several files used to change the behavior and
   appearance of XDM, as well as a few scripts and programs used to set up
   the desktop when XDM is running. Table 5.1, "XDM Configuration Files"
   summarizes the function of each of these files. The exact syntax and usage
   of these files is described in xdm(1).

   Table 5.1. XDM Configuration Files

      File                              Description                           
              The protocol for connecting to XDM is called the X Display      
              Manager Connection Protocol (XDMCP). This file is a client      
   Xaccess    authorization ruleset for controlling XDMCP connections from    
              remote machines. By default, this file does not allow any       
              remote clients to connect.                                      
              This file controls the look and feel of the XDM display chooser 
              and login screens. The default configuration is a simple        
   Xresources rectangular login window with the hostname of the machine       
              displayed at the top in a large font and "Login:" and           
              "Password:" prompts below. The format of this file is identical 
              to the app-defaults file described in the Xorg documentation.   
   Xservers   The list of local and remote displays the chooser should        
              provide as login choices.                                       
              Default session script for logins which is run by XDM after a   
   Xsession   user has logged in. This points to a customized session script  
              in ~/.xsession.                                                 
              Script to automatically launch applications before displaying   
              the chooser or login interfaces. There is a script for each     
   Xsetup_*   display being used, named Xsetup_*, where * is the local        
              display number. Typically these scripts run one or two programs 
              in the background such as xconsole.                             
   xdm-config Global configuration for all displays running on this machine.  
              Contains errors generated by the server program. If a display   
   xdm-errors that XDM is trying to start hangs, look at this file for error  
              messages. These messages are also written to the user's         
              ~/.xsession-errors on a per-session basis.                      
   xdm-pid    The running process ID of XDM.                                  

  5.6.2. Configuring Remote Access

   By default, only users on the same system can login using XDM. To enable
   users on other systems to connect to the display server, edit the access
   control rules and enable the connection listener.

   To configure XDM to listen for any remote connection, comment out the
   DisplayManager.requestPort line in /usr/local/etc/X11/xdm/xdm-config by
   putting a ! in front of it:

 ! SECURITY: do not listen for XDMCP or Chooser requests
 ! Comment out this line if you want to manage X terminals with xdm
 DisplayManager.requestPort:     0

   Save the edits and restart XDM. To restrict remote access, look at the
   example entries in /usr/local/etc/X11/xdm/Xaccess and refer to xdm(1) for
   further information.

5.7. Desktop Environments

   Contributed by Valentino Vaschetto.

   This section describes how to install three popular desktop environments
   on a FreeBSD system. A desktop environment can range from a simple window
   manager to a complete suite of desktop applications. Over a hundred
   desktop environments are available in the x11-wm category of the Ports
   Collection.

  5.7.1. GNOME

   GNOME is a user-friendly desktop environment. It includes a panel for
   starting applications and displaying status, a desktop, a set of tools and
   applications, and a set of conventions that make it easy for applications
   to cooperate and be consistent with each other. More information regarding
   GNOME on FreeBSD can be found at https://www.FreeBSD.org/gnome. That web
   site contains additional documentation about installing, configuring, and
   managing GNOME on FreeBSD.

   This desktop environment can be installed from a package:

 # pkg install gnome3

   To instead build GNOME from ports, use the following command. GNOME is a
   large application and will take some time to compile, even on a fast
   computer.

 # cd /usr/ports/x11/gnome3
 # make install clean

   GNOME requires /proc to be mounted. Add this line to /etc/fstab to mount
   this file system automatically during system startup:

 proc           /proc       procfs  rw  0   0

   GNOME uses D-Bus and HAL for a message bus and hardware abstraction. These
   applications are automatically installed as dependencies of GNOME. Enable
   them in /etc/rc.conf so they will be started when the system boots:

 dbus_enable="YES"
 hald_enable="YES"

   After installation, configure Xorg to start GNOME. The easiest way to do
   this is to enable the GNOME Display Manager, GDM, which is installed as
   part of the GNOME package or port. It can be enabled by adding this line
   to /etc/rc.conf:

 gdm_enable="YES"

   It is often desirable to also start all GNOME services. To achieve this,
   add a second line to /etc/rc.conf:

 gnome_enable="YES"

   GDM will start automatically when the system boots.

   A second method for starting GNOME is to type startx from the command-line
   after configuring ~/.xinitrc. If this file already exists, replace the
   line that starts the current window manager with one that starts
   /usr/local/bin/gnome-session. If this file does not exist, create it with
   this command:

 % echo "exec /usr/local/bin/gnome-session" > ~/.xinitrc

   A third method is to use XDM as the display manager. In this case, create
   an executable ~/.xsession:

 % echo "exec /usr/local/bin/gnome-session" > ~/.xsession

  5.7.2. KDE

   KDE is another easy-to-use desktop environment. This desktop provides a
   suite of applications with a consistent look and feel, a standardized menu
   and toolbars, keybindings, color-schemes, internationalization, and a
   centralized, dialog-driven desktop configuration. More information on KDE
   can be found at http://www.kde.org/. For FreeBSD-specific information,
   consult http://freebsd.kde.org.

   To install the KDE package, type:

 # pkg install x11/kde5

   To instead build the KDE port, use the following command. Installing the
   port will provide a menu for selecting which components to install. KDE is
   a large application and will take some time to compile, even on a fast
   computer.

 # cd /usr/ports/x11/kde5
 # make install clean

   KDE requires /proc to be mounted. Add this line to /etc/fstab to mount
   this file system automatically during system startup:

 proc           /proc       procfs  rw  0   0

   KDE uses D-Bus and HAL for a message bus and hardware abstraction. These
   applications are automatically installed as dependencies of KDE. Enable
   them in /etc/rc.conf so they will be started when the system boots:

 dbus_enable="YES"
 hald_enable="YES"

   Since KDE Plasma 5, the KDE Display Manager, KDM is no longer developed. A
   possible replacement is SDDM. To install it, type:

 # pkg install x11/sddm

   Add this line to /etc/rc.conf:

 sddm_enable="YES"

   A second method for launching KDE Plasma is to type startx from the
   command line. For this to work, the following line is needed in
   ~/.xinitrc:

 exec ck-launch-session startplasma-x11

   A third method for starting KDE Plasma is through XDM. To do so, create an
   executable ~/.xsession as follows:

 % echo "exec ck-launch-session startplasma-x11" > ~/.xsession

   Once KDE Plasma is started, refer to its built-in help system for more
   information on how to use its various menus and applications.

  5.7.3. Xfce

   Xfce is a desktop environment based on the GTK+ toolkit used by GNOME.
   However, it is more lightweight and provides a simple, efficient,
   easy-to-use desktop. It is fully configurable, has a main panel with
   menus, applets, and application launchers, provides a file manager and
   sound manager, and is themeable. Since it is fast, light, and efficient,
   it is ideal for older or slower machines with memory limitations. More
   information on Xfce can be found at http://www.xfce.org.

   To install the Xfce package:

 # pkg install xfce

   Alternatively, to build the port:

 # cd /usr/ports/x11-wm/xfce4
 # make install clean

   Xfce uses D-Bus for a message bus. This application is automatically
   installed as dependency of Xfce. Enable it in /etc/rc.conf so it will be
   started when the system boots:

 dbus_enable="YES"

   Unlike GNOME or KDE, Xfce does not provide its own login manager. In order
   to start Xfce from the command line by typing startx, first create
   ~/.xinitrc with this command:

 % echo ". /usr/local/etc/xdg/xfce4/xinitrc" > ~/.xinitrc

   An alternate method is to use XDM. To configure this method, create an
   executable ~/.xsession:

 % echo ". /usr/local/etc/xdg/xfce4/xinitrc" > ~/.xsession

5.8. Installing Compiz Fusion

   One way to make using a desktop computer more pleasant is with nice 3D
   effects.

   Installing the Compiz Fusion package is easy, but configuring it requires
   a few steps that are not described in the port's documentation.

  5.8.1. Setting up the FreeBSD nVidia Driver

   Desktop effects can cause quite a load on the graphics card. For an
   nVidia-based graphics card, the proprietary driver is required for good
   performance. Users of other graphics cards can skip this section and
   continue with the xorg.conf configuration.

   To determine which nVidia driver is needed see the FAQ question on the
   subject.

   Having determined the correct driver to use for your card, installation is
   as simple as installing any other package.

   For example, to install the latest driver:

 # pkg install x11/nvidia-driver

   The driver will create a kernel module, which needs to be loaded at system
   startup. Add the following line to /boot/loader.conf:

 nvidia_load="YES"

  Note:

   To immediately load the kernel module into the running kernel issue a
   command like kldload nvidia. However, it has been noted that some versions
   of Xorg will not function properly if the driver is not loaded at boot
   time. After editing /boot/loader.conf, a reboot is recommended.

   With the kernel module loaded, you normally only need to change a single
   line in xorg.conf to enable the proprietary driver:

   Find the following line in /etc/X11/xorg.conf:

 Driver      "nv"

   and change it to:

 Driver      "nvidia"

   Start the GUI as usual, and you should be greeted by the nVidia splash.
   Everything should work as usual.

  5.8.2. Configuring xorg.conf for Desktop Effects

   To enable Compiz Fusion, /etc/X11/xorg.conf needs to be modified:

   Add the following section to enable composite effects:

 Section "Extensions"
     Option         "Composite" "Enable"
 EndSection

   Locate the "Screen" section which should look similar to the one below:

 Section "Screen"
     Identifier     "Screen0"
     Device         "Card0"
     Monitor        "Monitor0"
     ...

   and add the following two lines (after "Monitor" will do):

 DefaultDepth    24
 Option         "AddARGBGLXVisuals" "True"

   Locate the "Subsection" that refers to the screen resolution that you wish
   to use. For example, if you wish to use 1280x1024, locate the section that
   follows. If the desired resolution does not appear in any subsection, you
   may add the relevant entry by hand:

 SubSection     "Display"
     Viewport    0 0
     Modes      "1280x1024"
 EndSubSection

   A color depth of 24 bits is needed for desktop composition, change the
   above subsection to:

 SubSection     "Display"
     Viewport    0 0
     Depth       24
     Modes      "1280x1024"
 EndSubSection

   Finally, confirm that the "glx" and "extmod" modules are loaded in the
   "Module" section:

 Section "Module"
     Load           "extmod"
     Load           "glx"
     ...

   The preceding can be done automatically with x11/nvidia-xconfig by running
   (as root):

 # nvidia-xconfig --add-argb-glx-visuals
 # nvidia-xconfig --composite
 # nvidia-xconfig --depth=24

  5.8.3. Installing and Configuring Compiz Fusion

   Installing Compiz Fusion is as simple as any other package:

 # pkg install x11-wm/compiz-fusion

   When the installation is finished, start your graphic desktop and at a
   terminal, enter the following commands (as a normal user):

 % compiz --replace --sm-disable --ignore-desktop-hints ccp &
 % emerald --replace &

   Your screen will flicker for a few seconds, as your window manager (e.g.,
   Metacity if you are using GNOME) is replaced by Compiz Fusion. Emerald
   takes care of the window decorations (i.e., close, minimize, maximize
   buttons, title bars and so on).

   You may convert this to a trivial script and have it run at startup
   automatically (e.g., by adding to "Sessions" in a GNOME desktop):

 #! /bin/sh
 compiz --replace --sm-disable --ignore-desktop-hints ccp &
 emerald --replace &

   Save this in your home directory as, for example, start-compiz and make it
   executable:

 % chmod +x ~/start-compiz

   Then use the GUI to add it to Startup Programs (located in System,
   Preferences, Sessions on a GNOME desktop).

   To actually select all the desired effects and their settings, execute
   (again as a normal user) the Compiz Config Settings Manager:

 % ccsm

  Note:

   In GNOME, this can also be found in the System, Preferences menu.

   If you have selected "gconf support" during the build, you will also be
   able to view these settings using gconf-editor under apps/compiz.

5.9. Troubleshooting

   If the mouse does not work, you will need to first configure it before
   proceeding. In recent Xorg versions, the InputDevice sections in xorg.conf
   are ignored in favor of the autodetected devices. To restore the old
   behavior, add the following line to the ServerLayout or ServerFlags
   section of this file:

 Option "AutoAddDevices" "false"

   Input devices may then be configured as in previous versions, along with
   any other options needed (e.g., keyboard layout switching).

  Note:

   As previously explained the hald daemon will, by default, automatically
   detect your keyboard. There are chances that your keyboard layout or model
   will not be correct, desktop environments like GNOME, KDE or Xfce provide
   tools to configure the keyboard. However, it is possible to set the
   keyboard properties directly either with the help of the setxkbmap(1)
   utility or with a hald's configuration rule.

   For example if, one wants to use a PC 102 keys keyboard coming with a
   french layout, we have to create a keyboard configuration file for hald
   called x11-input.fdi and saved in the /usr/local/etc/hal/fdi/policy
   directory. This file should contain the following lines:

 <?xml version="1.0" encoding="iso-8859-1"?>
 <deviceinfo version="0.2">
   <device>
     <match key="info.capabilities" contains="input.keyboard">
           <merge key="input.x11_options.XkbModel" type="string">pc102</merge>
           <merge key="input.x11_options.XkbLayout" type="string">fr</merge>
     </match>
   </device>
 </deviceinfo>

   If this file already exists, just copy and add to your file the lines
   regarding the keyboard configuration.

   You will have to reboot your machine to force hald to read this file.

   It is possible to do the same configuration from an X terminal or a script
   with this command line:

 % setxkbmap -model pc102 -layout fr

   /usr/local/share/X11/xkb/rules/base.lst lists the various keyboard,
   layouts and options available.

   The xorg.conf.new configuration file may now be tuned to taste. Open the
   file in a text editor such as emacs(1) or ee(1). If the monitor is an
   older or unusual model that does not support autodetection of sync
   frequencies, those settings can be added to xorg.conf.new under the
   "Monitor" section:

 Section "Monitor"
         Identifier   "Monitor0"
         VendorName   "Monitor Vendor"
         ModelName    "Monitor Model"
         HorizSync    30-107
         VertRefresh  48-120
 EndSection

   Most monitors support sync frequency autodetection, making manual entry of
   these values unnecessary. For the few monitors that do not support
   autodetection, avoid potential damage by only entering values provided by
   the manufacturer.

   X allows DPMS (Energy Star) features to be used with capable monitors. The
   xset(1) program controls the time-outs and can force standby, suspend, or
   off modes. If you wish to enable DPMS features for your monitor, you must
   add the following line to the monitor section:

 Option       "DPMS"

   While the xorg.conf.new configuration file is still open in an editor,
   select the default resolution and color depth desired. This is defined in
   the "Screen" section:

 Section "Screen"
         Identifier "Screen0"
         Device     "Card0"
         Monitor    "Monitor0"
         DefaultDepth 24
         SubSection "Display"
                 Viewport  0 0
                 Depth     24
                 Modes     "1024x768"
         EndSubSection
 EndSection

   The DefaultDepth keyword describes the color depth to run at by default.
   This can be overridden with the -depth command line switch to Xorg(1). The
   Modes keyword describes the resolution to run at for the given color
   depth. Note that only VESA standard modes are supported as defined by the
   target system's graphics hardware. In the example above, the default color
   depth is twenty-four bits per pixel. At this color depth, the accepted
   resolution is 1024 by 768 pixels.

   Finally, write the configuration file and test it using the test mode
   given above.

  Note:

   One of the tools available to assist you during troubleshooting process
   are the Xorg log files, which contain information on each device that the
   Xorg server attaches to. Xorg log file names are in the format of
   /var/log/Xorg.0.log. The exact name of the log can vary from Xorg.0.log to
   Xorg.8.log and so forth.

   If all is well, the configuration file needs to be installed in a common
   location where Xorg(1) can find it. This is typically /etc/X11/xorg.conf
   or /usr/local/etc/X11/xorg.conf.

 # cp xorg.conf.new /etc/X11/xorg.conf

   The Xorg configuration process is now complete. Xorg may be now started
   with the startx(1) utility. The Xorg server may also be started with the
   use of xdm(1).

  5.9.1. Configuration with Intel(R) i810 Graphics Chipsets

   Configuration with Intel(R) i810 integrated chipsets requires the agpgart
   AGP programming interface for Xorg to drive the card. See the agp(4)
   driver manual page for more information.

   This will allow configuration of the hardware as any other graphics board.
   Note on systems without the agp(4) driver compiled in the kernel, trying
   to load the module with kldload(8) will not work. This driver has to be in
   the kernel at boot time through being compiled in or using
   /boot/loader.conf.

  5.9.2. Adding a Widescreen Flatpanel to the Mix

   This section assumes a bit of advanced configuration knowledge. If
   attempts to use the standard configuration tools above have not resulted
   in a working configuration, there is information enough in the log files
   to be of use in getting the setup working. Use of a text editor will be
   necessary.

   Current widescreen (WSXGA, WSXGA+, WUXGA, WXGA, WXGA+, et.al.) formats
   support 16:10 and 10:9 formats or aspect ratios that can be problematic.
   Examples of some common screen resolutions for 16:10 aspect ratios are:

     * 2560x1600

     * 1920x1200

     * 1680x1050

     * 1440x900

     * 1280x800

   At some point, it will be as easy as adding one of these resolutions as a
   possible Mode in the Section "Screen" as such:

 Section "Screen"
 Identifier "Screen0"
 Device     "Card0"
 Monitor    "Monitor0"
 DefaultDepth 24
 SubSection "Display"
         Viewport  0 0
         Depth     24
         Modes     "1680x1050"
 EndSubSection
 EndSection

   Xorg is smart enough to pull the resolution information from the
   widescreen via I2C/DDC information so it knows what the monitor can handle
   as far as frequencies and resolutions.

   If those ModeLines do not exist in the drivers, one might need to give
   Xorg a little hint. Using /var/log/Xorg.0.log one can extract enough
   information to manually create a ModeLine that will work. Simply look for
   information resembling this:

 (II) MGA(0): Supported additional Video Mode:
 (II) MGA(0): clock: 146.2 MHz   Image Size:  433 x 271 mm
 (II) MGA(0): h_active: 1680  h_sync: 1784  h_sync_end 1960 h_blank_end 2240 h_border: 0
 (II) MGA(0): v_active: 1050  v_sync: 1053  v_sync_end 1059 v_blanking: 1089 v_border: 0
 (II) MGA(0): Ranges: V min: 48  V max: 85 Hz, H min: 30  H max: 94 kHz, PixClock max 170 MHz

   This information is called EDID information. Creating a ModeLine from this
   is just a matter of putting the numbers in the correct order:

 ModeLine <name> <clock> <4 horiz. timings> <4 vert. timings>

   So that the ModeLine in Section "Monitor" for this example would look like
   this:

 Section "Monitor"
 Identifier      "Monitor1"
 VendorName      "Bigname"
 ModelName       "BestModel"
 ModeLine        "1680x1050" 146.2 1680 1784 1960 2240 1050 1053 1059 1089
 Option          "DPMS"
 EndSection

   Now having completed these simple editing steps, X should start on your
   new widescreen monitor.

  5.9.3. Troubleshooting Compiz Fusion

   5.9.3.1. I have installed Compiz Fusion, and after running the commands
   you mention, my windows are left without title bars and buttons. What is
   wrong?

   5.9.3.2. When I run the command to start Compiz Fusion, the X server
   crashes and I am back at the console. What is wrong?

5.9.3.1. I have installed Compiz Fusion, and after running the commands you mention, my  
         windows are left without title bars and buttons. What is wrong?                 
         You are probably missing a setting in /etc/X11/xorg.conf. Review this file      
         carefully and check especially the DefaultDepth and AddARGBGLXVisuals           
         directives.                                                                     
5.9.3.2. When I run the command to start Compiz Fusion, the X server crashes and I am    
         back at the console. What is wrong?                                             
         If you check /var/log/Xorg.0.log, you will probably find error messages during  
         the X startup. The most common would be:                                        
                                                                                         
         (EE) NVIDIA(0):     Failed to initialize the GLX module; please check in your X 
         (EE) NVIDIA(0):     log file that the GLX module has been loaded in your X      
         (EE) NVIDIA(0):     server, and that the module is the NVIDIA GLX module.  If   
         (EE) NVIDIA(0):     you continue to encounter problems, Please try              
         (EE) NVIDIA(0):     reinstalling the NVIDIA driver.                             
                                                                                         
         This is usually the case when you upgrade Xorg. You will need to reinstall the  
         x11/nvidia-driver package so glx is built again.                                

                             Part II. Common Tasks

   Now that the basics have been covered, this part of the book discusses
   some frequently used features of FreeBSD. These chapters:

     * Introduce popular and useful desktop applications: browsers,
       productivity tools, document viewers, and more.

     * Introduce a number of multimedia tools available for FreeBSD.

     * Explain the process of building a customized FreeBSD kernel to enable
       extra functionality.

     * Describe the print system in detail, both for desktop and
       network-connected printer setups.

     * Show how to run Linux applications on the FreeBSD system.

   Some of these chapters recommend prior reading, and this is noted in the
   synopsis at the beginning of each chapter.

   Table of Contents

   6. Desktop Applications

                6.1. Synopsis

                6.2. Browsers

                6.3. Productivity

                6.4. Document Viewers

                6.5. Finance

   7. Multimedia

                7.1. Synopsis

                7.2. Setting Up the Sound Card

                7.3. MP3 Audio

                7.4. Video Playback

                7.5. TV Cards

                7.6. MythTV

                7.7. Image Scanners

   8. Configuring the FreeBSD Kernel

                8.1. Synopsis

                8.2. Why Build a Custom Kernel?

                8.3. Finding the System Hardware

                8.4. The Configuration File

                8.5. Building and Installing a Custom Kernel

                8.6. If Something Goes Wrong

   9. Printing

                9.1. Quick Start

                9.2. Printer Connections

                9.3. Common Page Description Languages

                9.4. Direct Printing

                9.5. LPD (Line Printer Daemon)

                9.6. Other Printing Systems

   10. Linux(R) Binary Compatibility

                10.1. Synopsis

                10.2. Configuring Linux(R) Binary Compatibility

                10.3. Advanced Topics

   11. WINE

                11.1. Synopsis

                11.2. WINE Overview & Concepts

                11.3. Installing WINE on FreeBSD

                11.4. Running a First WINE Program on FreeBSD

                11.5. Configuring WINE Installation

                11.6. WINE Management GUIs

                11.7. WINE in Multi-User FreeBSD Installations

                11.8. WINE on FreeBSD FAQ

Chapter 6. Desktop Applications

   Table of Contents

   6.1. Synopsis

   6.2. Browsers

   6.3. Productivity

   6.4. Document Viewers

   6.5. Finance

6.1. Synopsis

   While FreeBSD is popular as a server for its performance and stability, it
   is also suited for day-to-day use as a desktop. With over 24,000
   applications available as FreeBSD packages or ports, it is easy to build a
   customized desktop that runs a wide variety of desktop applications. This
   chapter demonstrates how to install numerous desktop applications,
   including web browsers, productivity software, document viewers, and
   financial software.

  Note:

   Users who prefer to install a pre-built desktop version of FreeBSD rather
   than configuring one from scratch should refer to GhostBSD, MidnightBSD or
   NomadBSD.

   Readers of this chapter should know how to:

     * Install additional software using packages or ports as described in
       Chapter 4, Installing Applications: Packages and Ports.

     * Install X and a window manager as described in Chapter 5, The X Window
       System.

   For information on how to configure a multimedia environment, refer to
   Chapter 7, Multimedia.

6.2. Browsers

   FreeBSD does not come with a pre-installed web browser. Instead, the www
   category of the Ports Collection contains many browsers which can be
   installed as a package or compiled from the Ports Collection.

   The KDE and GNOME desktop environments include their own HTML browser.
   Refer to Section 5.7, "Desktop Environments" for more information on how
   to set up these complete desktops.

   Some lightweight browsers include www/dillo2, www/links, and www/w3m.

   This section demonstrates how to install the following popular web
   browsers and indicates if the application is resource-heavy, takes time to
   compile from ports, or has any major dependencies.

   Application Name Resources Installation from             Notes             
                     Needed         Ports       
                                                FreeBSD, Linux(R), and        
   Firefox          medium    heavy             localized versions are        
                                                available                     
   Konqueror        medium    heavy             Requires KDE libraries        
   Chromium         medium    heavy             Requires Gtk+                 

  6.2.1. Firefox

   Firefox is an open source browser that features a standards-compliant HTML
   display engine, tabbed browsing, popup blocking, extensions, improved
   security, and more. Firefox is based on the Mozilla codebase.

   To install the package of the latest release version of Firefox, type:

 # pkg install firefox

   To instead install Firefox Extended Support Release (ESR) version, use:

 # pkg install firefox-esr

   The Ports Collection can instead be used to compile the desired version of
   Firefox from source code. This example builds www/firefox, where firefox
   can be replaced with the ESR or localized version to install.

 # cd /usr/ports/www/firefox
 # make install clean

  6.2.2. Konqueror

   Konqueror is more than a web browser as it is also a file manager and a
   multimedia viewer. Supports WebKit as well as its own KHTML. WebKit is a
   rendering engine used by many modern browsers including Chromium.

   Konqueror can be installed as a package by typing:

 # pkg install konqueror

   To install from the Ports Collection:

 # cd /usr/ports/x11-fm/konqueror/
 # make install clean

  6.2.3. Chromium

   Chromium is an open source browser project that aims to build a safer,
   faster, and more stable web browsing experience. Chromium features tabbed
   browsing, popup blocking, extensions, and much more. Chromium is the open
   source project upon which the Google Chrome web browser is based.

   Chromium can be installed as a package by typing:

 # pkg install chromium

   Alternatively, Chromium can be compiled from source using the Ports
   Collection:

 # cd /usr/ports/www/chromium
 # make install clean

  Note:

   The executable for Chromium is /usr/local/bin/chrome, not
   /usr/local/bin/chromium.

6.3. Productivity

   When it comes to productivity, users often look for an office suite or an
   easy-to-use word processor. While some desktop environments like KDE
   provide an office suite, there is no default productivity package. Several
   office suites and graphical word processors are available for FreeBSD,
   regardless of the installed window manager.

   This section demonstrates how to install the following popular
   productivity software and indicates if the application is resource-heavy,
   takes time to compile from ports, or has any major dependencies.

   Application Name    Resources    Installation from   Major Dependencies    
                         Needed           Ports       
   Calligra          light          heavy             KDE                     
   AbiWord           light          light             Gtk+ or GNOME           
   The Gimp          light          heavy             Gtk+                    
   Apache OpenOffice heavy          huge              JDK(TM) and Mozilla     
   LibreOffice       somewhat heavy huge              Gtk+, or KDE/ GNOME, or 
                                                      JDK(TM)                 

  6.3.1. Calligra

   The KDE desktop environment includes an office suite which can be
   installed separately from KDE. Calligra includes standard components that
   can be found in other office suites. Words is the word processor, Sheets
   is the spreadsheet program, Stage manages slide presentations, and Karbon
   is used to draw graphical documents.

   In FreeBSD, editors/calligra can be installed as a package or a port. To
   install the package:

 # pkg install calligra

   If the package is not available, use the Ports Collection instead:

 # cd /usr/ports/editors/calligra
 # make install clean

  6.3.2. AbiWord

   AbiWord is a free word processing program similar in look and feel to
   Microsoft(R) Word. It is fast, contains many features, and is
   user-friendly.

   AbiWord can import or export many file formats, including some proprietary
   ones like Microsoft(R) .rtf.

   To install the AbiWord package:

 # pkg install abiword

   If the package is not available, it can be compiled from the Ports
   Collection:

 # cd /usr/ports/editors/abiword
 # make install clean

  6.3.3. The GIMP

   For image authoring or picture retouching, The GIMP provides a
   sophisticated image manipulation program. It can be used as a simple paint
   program or as a quality photo retouching suite. It supports a large number
   of plugins and features a scripting interface. The GIMP can read and write
   a wide range of file formats and supports interfaces with scanners and
   tablets.

   To install the package:

 # pkg install gimp

   Alternately, use the Ports Collection:

 # cd /usr/ports/graphics/gimp
 # make install clean

   The graphics category (freebsd.org/ports/graphics.html) of the Ports
   Collection contains several GIMP-related plugins, help files, and user
   manuals.

  6.3.4. Apache OpenOffice

   Apache OpenOffice is an open source office suite which is developed under
   the wing of the Apache Software Foundation's Incubator. It includes all of
   the applications found in a complete office productivity suite: a word
   processor, spreadsheet, presentation manager, and drawing program. Its
   user interface is similar to other office suites, and it can import and
   export in various popular file formats. It is available in a number of
   different languages and internationalization has been extended to
   interfaces, spell checkers, and dictionaries.

   The word processor of Apache OpenOffice uses a native XML file format for
   increased portability and flexibility. The spreadsheet program features a
   macro language which can be interfaced with external databases. Apache
   OpenOffice is stable and runs natively on Windows(R), Solaris(TM),
   Linux(R), FreeBSD, and Mac OS(R) X. More information about Apache
   OpenOffice can be found at openoffice.org. For FreeBSD specific
   information refer to porting.openoffice.org/freebsd/.

   To install the Apache OpenOffice package:

 # pkg install apache-openoffice

   Once the package is installed, type the following command to launch Apache
   OpenOffice:

 % openoffice-X.Y.Z

   where X.Y.Z is the version number of the installed version of Apache
   OpenOffice. The first time Apache OpenOffice launches, some questions will
   be asked and a .openoffice.org folder will be created in the user's home
   directory.

   If the desired Apache OpenOffice package is not available, compiling the
   port is still an option. However, this requires a lot of disk space and a
   fairly long time to compile:

 # cd /usr/ports/editors/openoffice-4
 # make install clean

  Note:

   To build a localized version, replace the previous command with:

 # make LOCALIZED_LANG=your_language install clean

   Replace your_language with the correct language ISO-code. A list of
   supported language codes is available in files/Makefile.localized, located
   in the port's directory.

  6.3.5. LibreOffice

   LibreOffice is a free software office suite developed by
   documentfoundation.org. It is compatible with other major office suites
   and available on a variety of platforms. It is a rebranded fork of Apache
   OpenOffice and includes applications found in a complete office
   productivity suite: a word processor, spreadsheet, presentation manager,
   drawing program, database management program, and a tool for creating and
   editing mathematical formulae. It is available in a number of different
   languages and internationalization has been extended to interfaces, spell
   checkers, and dictionaries.

   The word processor of LibreOffice uses a native XML file format for
   increased portability and flexibility. The spreadsheet program features a
   macro language which can be interfaced with external databases.
   LibreOffice is stable and runs natively on Windows(R), Linux(R), FreeBSD,
   and Mac OS(R) X. More information about LibreOffice can be found at
   libreoffice.org.

   To install the English version of the LibreOffice package:

 # pkg install libreoffice

   The editors category (freebsd.org/ports/editors.html) of the Ports
   Collection contains several localizations for LibreOffice. When installing
   a localized package, replace libreoffice with the name of the localized
   package.

   Once the package is installed, type the following command to run
   LibreOffice:

 % libreoffice

   During the first launch, some questions will be asked and a .libreoffice
   folder will be created in the user's home directory.

   If the desired LibreOffice package is not available, compiling the port is
   still an option. However, this requires a lot of disk space and a fairly
   long time to compile. This example compiles the English version:

 # cd /usr/ports/editors/libreoffice
 # make install clean

  Note:

   To build a localized version, cd into the port directory of the desired
   language. Supported languages can be found in the editors category
   (freebsd.org/ports/editors.html) of the Ports Collection.

6.4. Document Viewers

   Some new document formats have gained popularity since the advent of
   UNIX(R) and the viewers they require may not be available in the base
   system. This section demonstrates how to install the following document
   viewers:

   Application Name Resources Needed   Installation from   Major Dependencies 
                                             Ports         
   Xpdf             light            light                 FreeType           
   gv               light            light                 Xaw3d              
   Geeqie           light            light                 Gtk+ or GNOME      
   ePDFView         light            light                 Gtk+               
   Okular           light            heavy                 KDE                

  6.4.1. Xpdf

   For users that prefer a small FreeBSD PDF viewer, Xpdf provides a
   light-weight and efficient viewer which requires few resources. It uses
   the standard X fonts and does not require any additional toolkits.

   To install the Xpdf package:

 # pkg install xpdf

   If the package is not available, use the Ports Collection:

 # cd /usr/ports/graphics/xpdf
 # make install clean

   Once the installation is complete, launch xpdf and use the right mouse
   button to activate the menu.

  6.4.2. gv

   gv is a PostScript(R) and PDF viewer. It is based on ghostview, but has a
   nicer look as it is based on the Xaw3d widget toolkit. gv has many
   configurable features, such as orientation, paper size, scale, and
   anti-aliasing. Almost any operation can be performed with either the
   keyboard or the mouse.

   To install gv as a package:

 # pkg install gv

   If a package is unavailable, use the Ports Collection:

 # cd /usr/ports/print/gv
 # make install clean

  6.4.3. Geeqie

   Geeqie is a fork from the unmaintained GQView project, in an effort to
   move development forward and integrate the existing patches. Geeqie is an
   image manager which supports viewing a file with a single click, launching
   an external editor, and thumbnail previews. It also features a slideshow
   mode and some basic file operations, making it easy to manage image
   collections and to find duplicate files. Geeqie supports full screen
   viewing and internationalization.

   To install the Geeqie package:

 # pkg install geeqie

   If the package is not available, use the Ports Collection:

 # cd /usr/ports/graphics/geeqie
 # make install clean

  6.4.4. ePDFView

   ePDFView is a lightweight PDF document viewer that only uses the Gtk+ and
   Poppler libraries. It is currently under development, but already opens
   most PDF files (even encrypted), save copies of documents, and has support
   for printing using CUPS.

   To install ePDFView as a package:

 # pkg install epdfview

   If a package is unavailable, use the Ports Collection:

 # cd /usr/ports/graphics/epdfview
 # make install clean

  6.4.5. Okular

   Okular is a universal document viewer based on KPDF for KDE. It can open
   many document formats, including PDF, PostScript(R), DjVu, CHM, XPS, and
   ePub.

   To install Okular as a package:

 # pkg install okular

   If a package is unavailable, use the Ports Collection:

 # cd /usr/ports/graphics/okular
 # make install clean

6.5. Finance

   For managing personal finances on a FreeBSD desktop, some powerful and
   easy-to-use applications can be installed. Some are compatible with
   widespread file formats, such as the formats used by Quicken and Excel.

   This section covers these programs:

   Application Name Resources Needed   Installation from   Major Dependencies 
                                             Ports         
   GnuCash          light            heavy                 GNOME              
   Gnumeric         light            heavy                 GNOME              
   KMyMoney         light            heavy                 KDE                

  6.5.1. GnuCash

   GnuCash is part of the GNOME effort to provide user-friendly, yet
   powerful, applications to end-users. GnuCash can be used to keep track of
   income and expenses, bank accounts, and stocks. It features an intuitive
   interface while remaining professional.

   GnuCash provides a smart register, a hierarchical system of accounts, and
   many keyboard accelerators and auto-completion methods. It can split a
   single transaction into several more detailed pieces. GnuCash can import
   and merge Quicken QIF files. It also handles most international date and
   currency formats.

   To install the GnuCash package:

 # pkg install gnucash

   If the package is not available, use the Ports Collection:

 # cd /usr/ports/finance/gnucash
 # make install clean

  6.5.2. Gnumeric

   Gnumeric is a spreadsheet program developed by the GNOME community. It
   features convenient automatic guessing of user input according to the cell
   format with an autofill system for many sequences. It can import files in
   a number of popular formats, including Excel, Lotus 1-2-3, and Quattro
   Pro. It has a large number of built-in functions and allows all of the
   usual cell formats such as number, currency, date, time, and much more.

   To install Gnumeric as a package:

 # pkg install gnumeric

   If the package is not available, use the Ports Collection:

 # cd /usr/ports/math/gnumeric
 # make install clean

  6.5.3. KMyMoney

   KMyMoney is a personal finance application created by the KDE community.
   KMyMoney aims to provide the important features found in commercial
   personal finance manager applications. It also highlights ease-of-use and
   proper double-entry accounting among its features. KMyMoney imports from
   standard Quicken QIF files, tracks investments, handles multiple
   currencies, and provides a wealth of reports.

   To install KMyMoney as a package:

 # pkg install kmymoney-kde4

   If the package is not available, use the Ports Collection:

 # cd /usr/ports/finance/kmymoney-kde4
 # make install clean

Chapter 7. Multimedia

   Edited by Ross Lippert.
   Table of Contents

   7.1. Synopsis

   7.2. Setting Up the Sound Card

   7.3. MP3 Audio

   7.4. Video Playback

   7.5. TV Cards

   7.6. MythTV

   7.7. Image Scanners

7.1. Synopsis

   FreeBSD supports a wide variety of sound cards, allowing users to enjoy
   high fidelity output from a FreeBSD system. This includes the ability to
   record and play back audio in the MPEG Audio Layer 3 (MP3), Waveform Audio
   File (WAV), Ogg Vorbis, and other formats. The FreeBSD Ports Collection
   contains many applications for editing recorded audio, adding sound
   effects, and controlling attached MIDI devices.

   FreeBSD also supports the playback of video files and DVDs. The FreeBSD
   Ports Collection contains applications to encode, convert, and playback
   various video media.

   This chapter describes how to configure sound cards, video playback, TV
   tuner cards, and scanners on FreeBSD. It also describes some of the
   applications which are available for using these devices.

   After reading this chapter, you will know how to:

     * Configure a sound card on FreeBSD.

     * Troubleshoot the sound setup.

     * Playback and encode MP3s and other audio.

     * Prepare a FreeBSD system for video playback.

     * Play DVDs, .mpg, and .avi files.

     * Rip CD and DVD content into files.

     * Configure a TV card.

     * Install and setup MythTV on FreeBSD

     * Configure an image scanner.

     * Configure a Bluetooth headset.

   Before reading this chapter, you should:

     * Know how to install applications as described in Chapter 4, Installing
       Applications: Packages and Ports.

7.2. Setting Up the Sound Card

   Contributed by Moses Moore.
   Enhanced by Marc Fonvieille.

   Before beginning the configuration, determine the model of the sound card
   and the chip it uses. FreeBSD supports a wide variety of sound cards.
   Check the supported audio devices list of the Hardware Notes to see if the
   card is supported and which FreeBSD driver it uses.

   In order to use the sound device, its device driver must be loaded. The
   easiest way is to load a kernel module for the sound card with kldload(8).
   This example loads the driver for a built-in audio chipset based on the
   Intel specification:

 # kldload snd_hda

   To automate the loading of this driver at boot time, add the driver to
   /boot/loader.conf. The line for this driver is:

 snd_hda_load="YES"

   Other available sound modules are listed in /boot/defaults/loader.conf.
   When unsure which driver to use, load the snd_driver module:

 # kldload snd_driver

   This is a metadriver which loads all of the most common sound drivers and
   can be used to speed up the search for the correct driver. It is also
   possible to load all sound drivers by adding the metadriver to
   /boot/loader.conf.

   To determine which driver was selected for the sound card after loading
   the snd_driver metadriver, type cat /dev/sndstat.

  7.2.1. Configuring a Custom Kernel with Sound Support

   This section is for users who prefer to statically compile in support for
   the sound card in a custom kernel. For more information about recompiling
   a kernel, refer to Chapter 8, Configuring the FreeBSD Kernel.

   When using a custom kernel to provide sound support, make sure that the
   audio framework driver exists in the custom kernel configuration file:

 device sound

   Next, add support for the sound card. To continue the example of the
   built-in audio chipset based on the Intel specification from the previous
   section, use the following line in the custom kernel configuration file:

 device snd_hda

   Be sure to read the manual page of the driver for the device name to use
   for the driver.

   Non-PnP ISA sound cards may require the IRQ and I/O port settings of the
   card to be added to /boot/device.hints. During the boot process, loader(8)
   reads this file and passes the settings to the kernel. For example, an old
   Creative SoundBlaster(R) 16 ISA non-PnP card will use the snd_sbc(4)
   driver in conjunction with snd_sb16. For this card, the following lines
   must be added to the kernel configuration file:

 device snd_sbc
 device snd_sb16

   If the card uses the 0x220 I/O port and IRQ 5, these lines must also be
   added to /boot/device.hints:

 hint.sbc.0.at="isa"
 hint.sbc.0.port="0x220"
 hint.sbc.0.irq="5"
 hint.sbc.0.drq="1"
 hint.sbc.0.flags="0x15"

   The syntax used in /boot/device.hints is described in sound(4) and the
   manual page for the driver of the sound card.

   The settings shown above are the defaults. In some cases, the IRQ or other
   settings may need to be changed to match the card. Refer to snd_sbc(4) for
   more information about this card.

  7.2.2. Testing Sound

   After loading the required module or rebooting into the custom kernel, the
   sound card should be detected. To confirm, run dmesg | grep pcm. This
   example is from a system with a built-in Conexant CX20590 chipset:

 pcm0: <NVIDIA (0x001c) (HDMI/DP 8ch)> at nid 5 on hdaa0
 pcm1: <NVIDIA (0x001c) (HDMI/DP 8ch)> at nid 6 on hdaa0
 pcm2: <Conexant CX20590 (Analog 2.0+HP/2.0)> at nid 31,25 and 35,27 on hdaa1

   The status of the sound card may also be checked using this command:

 # cat /dev/sndstat
 FreeBSD Audio Driver (newpcm: 64bit 2009061500/amd64)
 Installed devices:
 pcm0: <NVIDIA (0x001c) (HDMI/DP 8ch)> (play)
 pcm1: <NVIDIA (0x001c) (HDMI/DP 8ch)> (play)
 pcm2: <Conexant CX20590 (Analog 2.0+HP/2.0)> (play/rec) default

   The output will vary depending upon the sound card. If no pcm devices are
   listed, double-check that the correct device driver was loaded or compiled
   into the kernel. The next section lists some common problems and their
   solutions.

   If all goes well, the sound card should now work in FreeBSD. If the CD or
   DVD drive is properly connected to the sound card, one can insert an audio
   CD in the drive and play it with cdcontrol(1):

 % cdcontrol -f /dev/acd0 play 1

  Warning:

   Audio CDs have specialized encodings which means that they should not be
   mounted using mount(8).

   Various applications, such as audio/workman, provide a friendlier
   interface. The audio/mpg123 port can be installed to listen to MP3 audio
   files.

   Another quick way to test the card is to send data to /dev/dsp:

 % cat filename > /dev/dsp

   where filename can be any type of file. This command should produce some
   noise, confirming that the sound card is working.

  Note:

   The /dev/dsp* device nodes will be created automatically as needed. When
   not in use, they do not exist and will not appear in the output of ls(1).

  7.2.3. Setting up Bluetooth Sound Devices

   Connecting to a Bluetooth device is out of scope for this chapter. Refer
   to Section 32.5, "Bluetooth" for more information.

   To get Bluetooth sound sink working with FreeBSD's sound system, users
   have to install audio/virtual_oss first:

 # pkg install virtual_oss

   audio/virtual_oss requires cuse to be loaded into the kernel:

 # kldload cuse

   To load cuse during system startup, run this command:

 # sysrc -f /boot/loader.conf cuse_load=yes

   To use headphones as a sound sink with audio/virtual_oss, users need to
   create a virtual device after connecting to a Bluetooth audio device:

 # virtual_oss -C 2 -c 2 -r 48000 -b 16 -s 768 -R /dev/null -P /dev/bluetooth/headphones -d dsp

  Note:

   headphones in this example is a hostname from /etc/bluetooth/hosts.
   BT_ADDR could be used instead.

   Refer to virtual_oss(8) for more information.

  7.2.4. Troubleshooting Sound

   Table 7.1, "Common Error Messages" lists some common error messages and
   their solutions:

   Table 7.1. Common Error Messages

             Error                               Solution                     
   sb_dspwr(XX) timed out     The I/O port is not set correctly.              
   bad irq XX                 The IRQ is set incorrectly. Make sure that the  
                              set IRQ and the sound IRQ are the same.         
   xxx: gus pcm not attached, There is not enough available memory to use the 
   out of memory              device.                                         
                              Type fstat | grep dsp to check if another       
   xxx: can't open /dev/dsp!  application is holding the device open.         
                              Noteworthy troublemakers are esound and KDE's   
                              sound support.                                  

   Modern graphics cards often come with their own sound driver for use with
   HDMI. This sound device is sometimes enumerated before the sound card
   meaning that the sound card will not be used as the default playback
   device. To check if this is the case, run dmesg and look for pcm. The
   output looks something like this:

 ...
 hdac0: HDA Driver Revision: 20100226_0142
 hdac1: HDA Driver Revision: 20100226_0142
 hdac0: HDA Codec #0: NVidia (Unknown)
 hdac0: HDA Codec #1: NVidia (Unknown)
 hdac0: HDA Codec #2: NVidia (Unknown)
 hdac0: HDA Codec #3: NVidia (Unknown)
 pcm0: <HDA NVidia (Unknown) PCM #0 DisplayPort> at cad 0 nid 1 on hdac0
 pcm1: <HDA NVidia (Unknown) PCM #0 DisplayPort> at cad 1 nid 1 on hdac0
 pcm2: <HDA NVidia (Unknown) PCM #0 DisplayPort> at cad 2 nid 1 on hdac0
 pcm3: <HDA NVidia (Unknown) PCM #0 DisplayPort> at cad 3 nid 1 on hdac0
 hdac1: HDA Codec #2: Realtek ALC889
 pcm4: <HDA Realtek ALC889 PCM #0 Analog> at cad 2 nid 1 on hdac1
 pcm5: <HDA Realtek ALC889 PCM #1 Analog> at cad 2 nid 1 on hdac1
 pcm6: <HDA Realtek ALC889 PCM #2 Digital> at cad 2 nid 1 on hdac1
 pcm7: <HDA Realtek ALC889 PCM #3 Digital> at cad 2 nid 1 on hdac1
 ...

   In this example, the graphics card (NVidia) has been enumerated before the
   sound card (Realtek ALC889). To use the sound card as the default playback
   device, change hw.snd.default_unit to the unit that should be used for
   playback:

 # sysctl hw.snd.default_unit=n

   where n is the number of the sound device to use. In this example, it
   should be 4. Make this change permanent by adding the following line to
   /etc/sysctl.conf:

 hw.snd.default_unit=4

  7.2.5. Utilizing Multiple Sound Sources

   Contributed by Munish Chopra.

   It is often desirable to have multiple sources of sound that are able to
   play simultaneously. FreeBSD uses "Virtual Sound Channels" to multiplex
   the sound card's playback by mixing sound in the kernel.

   Three sysctl(8) knobs are available for configuring virtual channels:

 # sysctl dev.pcm.0.play.vchans=4
 # sysctl dev.pcm.0.rec.vchans=4
 # sysctl hw.snd.maxautovchans=4

   This example allocates four virtual channels, which is a practical number
   for everyday use. Both dev.pcm.0.play.vchans=4 and dev.pcm.0.rec.vchans=4
   are configurable after a device has been attached and represent the number
   of virtual channels pcm0 has for playback and recording. Since the pcm
   module can be loaded independently of the hardware drivers,
   hw.snd.maxautovchans indicates how many virtual channels will be given to
   an audio device when it is attached. Refer to pcm(4) for more information.

  Note:

   The number of virtual channels for a device cannot be changed while it is
   in use. First, close any programs using the device, such as music players
   or sound daemons.

   The correct pcm device will automatically be allocated transparently to a
   program that requests /dev/dsp0.

  7.2.6. Setting Default Values for Mixer Channels

   Contributed by Josef El-Rayes.

   The default values for the different mixer channels are hardcoded in the
   source code of the pcm(4) driver. While sound card mixer levels can be
   changed using mixer(8) or third-party applications and daemons, this is
   not a permanent solution. To instead set default mixer values at the
   driver level, define the appropriate values in /boot/device.hints, as seen
   in this example:

 hint.pcm.0.vol="50"

   This will set the volume channel to a default value of 50 when the pcm(4)
   module is loaded.

7.3. MP3 Audio

   Contributed by Chern Lee.

   This section describes some MP3 players available for FreeBSD, how to rip
   audio CD tracks, and how to encode and decode MP3s.

  7.3.1. MP3 Players

   A popular graphical MP3 player is Audacious. It supports Winamp skins and
   additional plugins. The interface is intuitive, with a playlist, graphic
   equalizer, and more. Those familiar with Winamp will find Audacious simple
   to use. On FreeBSD, Audacious can be installed from the
   multimedia/audacious port or package. Audacious is a descendant of XMMS.

   The audio/mpg123 package or port provides an alternative, command-line MP3
   player. Once installed, specify the MP3 file to play on the command line.
   If the system has multiple audio devices, the sound device can also be
   specified:

 # mpg123 -a /dev/dsp1.0 Foobar-GreatestHits.mp3
 High Performance MPEG 1.0/2.0/2.5 Audio Player for Layers 1, 2 and 3
         version 1.18.1; written and copyright by Michael Hipp and others
         free software (LGPL) without any warranty but with best wishes

 Playing MPEG stream from Foobar-GreatestHits.mp3 ...
 MPEG 1.0 layer III, 128 kbit/s, 44100 Hz joint-stereo

   Additional MP3 players are available in the FreeBSD Ports Collection.

  7.3.2. Ripping CD Audio Tracks

   Before encoding a CD or CD track to MP3, the audio data on the CD must be
   ripped to the hard drive. This is done by copying the raw CD Digital Audio
   (CDDA) data to WAV files.

   The cdda2wav tool, which is installed with the sysutils/cdrtools suite,
   can be used to rip audio information from CDs.

   With the audio CD in the drive, the following command can be issued as
   root to rip an entire CD into individual, per track, WAV files:

 # cdda2wav -D 0,1,0 -B

   In this example, the -D 0,1,0 indicates the SCSI device 0,1,0 containing
   the CD to rip. Use cdrecord -scanbus to determine the correct device
   parameters for the system.

   To rip individual tracks, use -t to specify the track:

 # cdda2wav -D 0,1,0 -t 7

   To rip a range of tracks, such as track one to seven, specify a range:

 # cdda2wav -D 0,1,0 -t 1+7

   To rip from an ATAPI (IDE) CDROM drive, specify the device name in place
   of the SCSI unit numbers. For example, to rip track 7 from an IDE drive:

 # cdda2wav -D /dev/acd0 -t 7

   Alternately, dd can be used to extract audio tracks on ATAPI drives, as
   described in Section 18.5.5, "Duplicating Audio CDs".

  7.3.3. Encoding and Decoding MP3s

   Lame is a popular MP3 encoder which can be installed from the audio/lame
   port. Due to patent issues, a package is not available.

   The following command will convert the ripped WAV file audio01.wav to
   audio01.mp3:

 # lame -h -b 128 --tt "Foo Song Title" --ta "FooBar Artist" --tl "FooBar Album" \
 --ty "2014" --tc "Ripped and encoded by Foo" --tg "Genre" audio01.wav audio01.mp3

   The specified 128 kbits is a standard MP3 bitrate while the 160 and 192
   bitrates provide higher quality. The higher the bitrate, the larger the
   size of the resulting MP3. The -h turns on the "higher quality but a
   little slower" mode. The options beginning with --t indicate ID3 tags,
   which usually contain song information, to be embedded within the MP3
   file. Additional encoding options can be found in the lame manual page.

   In order to burn an audio CD from MP3s, they must first be converted to a
   non-compressed file format. XMMS can be used to convert to the WAV format,
   while mpg123 can be used to convert to the raw Pulse-Code Modulation (PCM)
   audio data format.

   To convert audio01.mp3 using mpg123, specify the name of the PCM file:

 # mpg123 -s audio01.mp3 > audio01.pcm

   To use XMMS to convert a MP3 to WAV format, use these steps:

   Procedure 7.1. Converting to WAV Format in XMMS
    1. Launch XMMS.

    2. Right-click the window to bring up the XMMS menu.

    3. Select Preferences under Options.

    4. Change the Output Plugin to "Disk Writer Plugin".

    5. Press Configure.

    6. Enter or browse to a directory to write the uncompressed files to.

    7. Load the MP3 file into XMMS as usual, with volume at 100% and EQ
       settings turned off.

    8. Press Play. The XMMS will appear as if it is playing the MP3, but no
       music will be heard. It is actually playing the MP3 to a file.

    9. When finished, be sure to set the default Output Plugin back to what
       it was before in order to listen to MP3s again.

   Both the WAV and PCM formats can be used with cdrecord. When using WAV
   files, there will be a small tick sound at the beginning of each track.
   This sound is the header of the WAV file. The audio/sox port or package
   can be used to remove the header:

 % sox -t wav -r 44100 -s -w -c 2 track.wav track.raw

   Refer to Section 18.5, "Creating and Using CD Media" for more information
   on using a CD burner in FreeBSD.

7.4. Video Playback

   Contributed by Ross Lippert.

   Before configuring video playback, determine the model and chipset of the
   video card. While Xorg supports a wide variety of video cards, not all
   provide good playback performance. To obtain a list of extensions
   supported by the Xorg server using the card, run xdpyinfo while Xorg is
   running.

   It is a good idea to have a short MPEG test file for evaluating various
   players and options. Since some DVD applications look for DVD media in
   /dev/dvd by default, or have this device name hardcoded in them, it might
   be useful to make a symbolic link to the proper device:

 # ln -sf /dev/cd0 /dev/dvd

   Due to the nature of devfs(5), manually created links will not persist
   after a system reboot. In order to recreate the symbolic link
   automatically when the system boots, add the following line to
   /etc/devfs.conf:

 link cd0 dvd

   DVD decryption invokes certain functions that require write permission to
   the DVD device.

   To enhance the shared memory Xorg interface, it is recommended to increase
   the values of these sysctl(8) variables:

 kern.ipc.shmmax=67108864
 kern.ipc.shmall=32768

  7.4.1. Determining Video Capabilities

   There are several possible ways to display video under Xorg and what works
   is largely hardware dependent. Each method described below will have
   varying quality across different hardware.

   Common video interfaces include:

    1. Xorg: normal output using shared memory.

    2. XVideo: an extension to the Xorg interface which allows video to be
       directly displayed in drawable objects through a special acceleration.
       This extension provides good quality playback even on low-end
       machines. The next section describes how to determine if this
       extension is running.

    3. SDL: the Simple Directmedia Layer is a porting layer for many
       operating systems, allowing cross-platform applications to be
       developed which make efficient use of sound and graphics. SDL provides
       a low-level abstraction to the hardware which can sometimes be more
       efficient than the Xorg interface. On FreeBSD, SDL can be installed
       using the devel/sdl20 package or port.

    4. DGA: the Direct Graphics Access is an Xorg extension which allows a
       program to bypass the Xorg server and directly alter the framebuffer.
       As it relies on a low-level memory mapping, programs using it must be
       run as root. The DGA extension can be tested and benchmarked using
       dga(1). When dga is running, it changes the colors of the display
       whenever a key is pressed. To quit, press q.

    5. SVGAlib: a low level console graphics layer.

    7.4.1.1. XVideo

   To check whether this extension is running, use xvinfo:

 % xvinfo

   XVideo is supported for the card if the result is similar to:

 X-Video Extension version 2.2
   screen #0
   Adaptor #0: "Savage Streams Engine"
     number of ports: 1
     port base: 43
     operations supported: PutImage
     supported visuals:
       depth 16, visualID 0x22
       depth 16, visualID 0x23
     number of attributes: 5
       "XV_COLORKEY" (range 0 to 16777215)
               client settable attribute
               client gettable attribute (current value is 2110)
       "XV_BRIGHTNESS" (range -128 to 127)
               client settable attribute
               client gettable attribute (current value is 0)
       "XV_CONTRAST" (range 0 to 255)
               client settable attribute
               client gettable attribute (current value is 128)
       "XV_SATURATION" (range 0 to 255)
               client settable attribute
               client gettable attribute (current value is 128)
       "XV_HUE" (range -180 to 180)
               client settable attribute
               client gettable attribute (current value is 0)
     maximum XvImage size: 1024 x 1024
     Number of image formats: 7
       id: 0x32595559 (YUY2)
         guid: 59555932-0000-0010-8000-00aa00389b71
         bits per pixel: 16
         number of planes: 1
         type: YUV (packed)
       id: 0x32315659 (YV12)
         guid: 59563132-0000-0010-8000-00aa00389b71
         bits per pixel: 12
         number of planes: 3
         type: YUV (planar)
       id: 0x30323449 (I420)
         guid: 49343230-0000-0010-8000-00aa00389b71
         bits per pixel: 12
         number of planes: 3
         type: YUV (planar)
       id: 0x36315652 (RV16)
         guid: 52563135-0000-0000-0000-000000000000
         bits per pixel: 16
         number of planes: 1
         type: RGB (packed)
         depth: 0
         red, green, blue masks: 0x1f, 0x3e0, 0x7c00
       id: 0x35315652 (RV15)
         guid: 52563136-0000-0000-0000-000000000000
         bits per pixel: 16
         number of planes: 1
         type: RGB (packed)
         depth: 0
         red, green, blue masks: 0x1f, 0x7e0, 0xf800
       id: 0x31313259 (Y211)
         guid: 59323131-0000-0010-8000-00aa00389b71
         bits per pixel: 6
         number of planes: 3
         type: YUV (packed)
       id: 0x0
         guid: 00000000-0000-0000-0000-000000000000
         bits per pixel: 0
         number of planes: 0
         type: RGB (packed)
         depth: 1
         red, green, blue masks: 0x0, 0x0, 0x0

   The formats listed, such as YUV2 and YUV12, are not present with every
   implementation of XVideo and their absence may hinder some players.

   If the result instead looks like:

 X-Video Extension version 2.2
 screen #0
 no adaptors present

   XVideo is probably not supported for the card. This means that it will be
   more difficult for the display to meet the computational demands of
   rendering video, depending on the video card and processor.

  7.4.2. Ports and Packages Dealing with Video

   This section introduces some of the software available from the FreeBSD
   Ports Collection which can be used for video playback.

    7.4.2.1. MPlayer and MEncoder

   MPlayer is a command-line video player with an optional graphical
   interface which aims to provide speed and flexibility. Other graphical
   front-ends to MPlayer are available from the FreeBSD Ports Collection.

   MPlayer can be installed using the multimedia/mplayer package or port.
   Several compile options are available and a variety of hardware checks
   occur during the build process. For these reasons, some users prefer to
   build the port rather than install the package.

   When compiling the port, the menu options should be reviewed to determine
   the type of support to compile into the port. If an option is not
   selected, MPlayer will not be able to display that type of video format.
   Use the arrow keys and spacebar to select the required formats. When
   finished, press Enter to continue the port compile and installation.

   By default, the package or port will build the mplayer command line
   utility and the gmplayer graphical utility. To encode videos, compile the
   multimedia/mencoder port. Due to licensing restrictions, a package is not
   available for MEncoder.

   The first time MPlayer is run, it will create ~/.mplayer in the user's
   home directory. This subdirectory contains default versions of the
   user-specific configuration files.

   This section describes only a few common uses. Refer to mplayer(1) for a
   complete description of its numerous options.

   To play the file testfile.avi, specify the video interfaces with -vo, as
   seen in the following examples:

 % mplayer -vo xv testfile.avi

 % mplayer -vo sdl testfile.avi

 % mplayer -vo x11 testfile.avi

 # mplayer -vo dga testfile.avi

 # mplayer -vo 'sdl:dga' testfile.avi

   It is worth trying all of these options, as their relative performance
   depends on many factors and will vary significantly with hardware.

   To play a DVD, replace testfile.avi with dvd://N -dvd-device DEVICE, where
   N is the title number to play and DEVICE is the device node for the DVD.
   For example, to play title 3 from /dev/dvd:

 # mplayer -vo xv dvd://3 -dvd-device /dev/dvd

  Note:

   The default DVD device can be defined during the build of the MPlayer port
   by including the WITH_DVD_DEVICE=/path/to/desired/device option. By
   default, the device is /dev/cd0. More details can be found in the port's
   Makefile.options.

   To stop, pause, advance, and so on, use a keybinding. To see the list of
   keybindings, run mplayer -h or read mplayer(1).

   Additional playback options include -fs -zoom, which engages fullscreen
   mode, and -framedrop, which helps performance.

   Each user can add commonly used options to their ~/.mplayer/config like
   so:

 vo=xv
 fs=yes
 zoom=yes

   mplayer can be used to rip a DVD title to a .vob. To dump the second title
   from a DVD:

 # mplayer -dumpstream -dumpfile out.vob dvd://2 -dvd-device /dev/dvd

   The output file, out.vob, will be in MPEG format.

   Anyone wishing to obtain a high level of expertise with UNIX(R) video
   should consult mplayerhq.hu/DOCS as it is technically informative. This
   documentation should be considered as required reading before submitting
   any bug reports.

   Before using mencoder, it is a good idea to become familiar with the
   options described at mplayerhq.hu/DOCS/HTML/en/mencoder.html. There are
   innumerable ways to improve quality, lower bitrate, and change formats,
   and some of these options may make the difference between good or bad
   performance. Improper combinations of command line options can yield
   output files that are unplayable even by mplayer.

   Here is an example of a simple copy:

 % mencoder input.avi -oac copy -ovc copy -o output.avi

   To rip to a file, use -dumpfile with mplayer.

   To convert input.avi to the MPEG4 codec with MPEG3 audio encoding, first
   install the audio/lame port. Due to licensing restrictions, a package is
   not available. Once installed, type:

 % mencoder input.avi -oac mp3lame -lameopts br=192 \
          -ovc lavc -lavcopts vcodec=mpeg4:vhq -o output.avi

   This will produce output playable by applications such as mplayer and
   xine.

   input.avi can be replaced with dvd://1 -dvd-device /dev/dvd and run as
   root to re-encode a DVD title directly. Since it may take a few tries to
   get the desired result, it is recommended to instead dump the title to a
   file and to work on the file.

    7.4.2.2. The xine Video Player

   xine is a video player with a reusable base library and a modular
   executable which can be extended with plugins. It can be installed using
   the multimedia/xine package or port.

   In practice, xine requires either a fast CPU with a fast video card, or
   support for the XVideo extension. The xine video player performs best on
   XVideo interfaces.

   By default, the xine player starts a graphical user interface. The menus
   can then be used to open a specific file.

   Alternatively, xine may be invoked from the command line by specifying the
   name of the file to play:

 % xine -g -p mymovie.avi

   Refer to xine-project.org/faq for more information and troubleshooting
   tips.

    7.4.2.3. The Transcode Utilities

   Transcode provides a suite of tools for re-encoding video and audio files.
   Transcode can be used to merge video files or repair broken files using
   command line tools with stdin/stdout stream interfaces.

   In FreeBSD, Transcode can be installed using the multimedia/transcode
   package or port. Many users prefer to compile the port as it provides a
   menu of compile options for specifying the support and codecs to compile
   in. If an option is not selected, Transcode will not be able to encode
   that format. Use the arrow keys and spacebar to select the required
   formats. When finished, press Enter to continue the port compile and
   installation.

   This example demonstrates how to convert a DivX file into a PAL MPEG-1
   file (PAL VCD):

 % transcode -i input.avi -V --export_prof vcd-pal -o output_vcd
 % mplex -f 1 -o output_vcd.mpg output_vcd.m1v output_vcd.mpa

   The resulting MPEG file, output_vcd.mpg, is ready to be played with
   MPlayer. The file can be burned on a CD media to create a video CD using a
   utility such as multimedia/vcdimager or sysutils/cdrdao.

   In addition to the manual page for transcode, refer to
   transcoding.org/cgi-bin/transcode for further information and examples.

7.5. TV Cards

   Original contribution by Josef El-Rayes.
   Enhanced and adapted by Marc Fonvieille.

   TV cards can be used to watch broadcast or cable TV on a computer. Most
   cards accept composite video via an RCA or S-video input and some cards
   include a FM radio tuner.

   FreeBSD provides support for PCI-based TV cards using a Brooktree
   Bt848/849/878/879 video capture chip with the bktr(4) driver. This driver
   supports most Pinnacle PCTV video cards. Before purchasing a TV card,
   consult bktr(4) for a list of supported tuners.

  7.5.1. Loading the Driver

   In order to use the card, the bktr(4) driver must be loaded. To automate
   this at boot time, add the following line to /boot/loader.conf:

 bktr_load="YES"

   Alternatively, one can statically compile support for the TV card into a
   custom kernel. In that case, add the following lines to the custom kernel
   configuration file:

 device   bktr
 device  iicbus
 device  iicbb
 device  smbus

   These additional devices are necessary as the card components are
   interconnected via an I2C bus. Then, build and install a new kernel.

   To test that the tuner is correctly detected, reboot the system. The TV
   card should appear in the boot messages, as seen in this example:

 bktr0: <BrookTree 848A> mem 0xd7000000-0xd7000fff irq 10 at device 10.0 on pci0
 iicbb0: <I2C bit-banging driver> on bti2c0
 iicbus0: <Philips I2C bus> on iicbb0 master-only
 iicbus1: <Philips I2C bus> on iicbb0 master-only
 smbus0: <System Management Bus> on bti2c0
 bktr0: Pinnacle/Miro TV, Philips SECAM tuner.

   The messages will differ according to the hardware. If necessary, it is
   possible to override some of the detected parameters using sysctl(8) or
   custom kernel configuration options. For example, to force the tuner to a
   Philips SECAM tuner, add the following line to a custom kernel
   configuration file:

 options OVERRIDE_TUNER=6

   or, use sysctl(8):

 # sysctl hw.bt848.tuner=6

   Refer to bktr(4) for a description of the available sysctl(8) parameters
   and kernel options.

  7.5.2. Useful Applications

   To use the TV card, install one of the following applications:

     * multimedia/fxtv provides TV-in-a-window and image/audio/video capture
       capabilities.

     * multimedia/xawtv is another TV application with similar features.

     * audio/xmradio provides an application for using the FM radio tuner of
       a TV card.

   More applications are available in the FreeBSD Ports Collection.

  7.5.3. Troubleshooting

   If any problems are encountered with the TV card, check that the video
   capture chip and the tuner are supported by bktr(4) and that the right
   configuration options were used. For more support or to ask questions
   about supported TV cards, refer to the freebsd-multimedia mailing list.

7.6. MythTV

   MythTV is a popular, open source Personal Video Recorder (PVR)
   application. This section demonstrates how to install and setup MythTV on
   FreeBSD. Refer to mythtv.org/wiki for more information on how to use
   MythTV.

   MythTV requires a frontend and a backend. These components can either be
   installed on the same system or on different machines.

   The frontend can be installed on FreeBSD using the
   multimedia/mythtv-frontend package or port. Xorg must also be installed
   and configured as described in Chapter 5, The X Window System. Ideally,
   this system has a video card that supports X-Video Motion Compensation
   (XvMC) and, optionally, a Linux Infrared Remote Control (LIRC)-compatible
   remote.

   To install both the backend and the frontend on FreeBSD, use the
   multimedia/mythtv package or port. A MySQL(TM) database server is also
   required and should automatically be installed as a dependency.
   Optionally, this system should have a tuner card and sufficient storage to
   hold recorded data.

  7.6.1. Hardware

   MythTV uses Video for Linux (V4L) to access video input devices such as
   encoders and tuners. In FreeBSD, MythTV works best with USB DVB-S/C/T
   cards as they are well supported by the multimedia/webcamd package or port
   which provides a V4L userland application. Any Digital Video Broadcasting
   (DVB) card supported by webcamd should work with MythTV. A list of known
   working cards can be found at wiki.freebsd.org/WebcamCompat. Drivers are
   also available for Hauppauge cards in the multimedia/pvr250 and
   multimedia/pvrxxx ports, but they provide a non-standard driver interface
   that does not work with versions of MythTV greater than 0.23. Due to
   licensing restrictions, no packages are available and these two ports must
   be compiled.

   The wiki.freebsd.org/HTPC page contains a list of all available DVB
   drivers.

  7.6.2. Setting up the MythTV Backend

   To install MythTV using binary packages:

 # pkg install mythtv

   Alternatively, to install from the Ports Collection:

 # cd /usr/ports/multimedia/mythtv
 # make install

   Once installed, set up the MythTV database:

 # mysql -uroot -p < /usr/local/share/mythtv/database/mc.sql

   Then, configure the backend:

 # mythtv-setup

   Finally, start the backend:

 # sysrc mythbackend_enable=yes
 # service mythbackend start

7.7. Image Scanners

   Written by Marc Fonvieille.

   In FreeBSD, access to image scanners is provided by SANE (Scanner Access
   Now Easy), which is available in the FreeBSD Ports Collection. SANE will
   also use some FreeBSD device drivers to provide access to the scanner
   hardware.

   FreeBSD supports both SCSI and USB scanners. Depending upon the scanner
   interface, different device drivers are required. Be sure the scanner is
   supported by SANE prior to performing any configuration. Refer to
   http://www.sane-project.org/sane-supported-devices.html for more
   information about supported scanners.

   This chapter describes how to determine if the scanner has been detected
   by FreeBSD. It then provides an overview of how to configure and use SANE
   on a FreeBSD system.

  7.7.1. Checking the Scanner

   The GENERIC kernel includes the device drivers needed to support USB
   scanners. Users with a custom kernel should ensure that the following
   lines are present in the custom kernel configuration file:

 device usb
 device uhci
 device ohci
 device ehci
 device xhci

   To determine if the USB scanner is detected, plug it in and use dmesg to
   determine whether the scanner appears in the system message buffer. If it
   does, it should display a message similar to this:

 ugen0.2: <EPSON> at usbus0

   In this example, an EPSON Perfection(R) 1650 USB scanner was detected on
   /dev/ugen0.2.

   If the scanner uses a SCSI interface, it is important to know which SCSI
   controller board it will use. Depending upon the SCSI chipset, a custom
   kernel configuration file may be needed. The GENERIC kernel supports the
   most common SCSI controllers. Refer to /usr/src/sys/conf/NOTES to
   determine the correct line to add to a custom kernel configuration file.
   In addition to the SCSI adapter driver, the following lines are needed in
   a custom kernel configuration file:

 device scbus
 device pass

   Verify that the device is displayed in the system message buffer:

 pass2 at aic0 bus 0 target 2 lun 0
 pass2: <AGFA SNAPSCAN 600 1.10> Fixed Scanner SCSI-2 device
 pass2: 3.300MB/s transfers

   If the scanner was not powered-on at system boot, it is still possible to
   manually force detection by performing a SCSI bus scan with camcontrol:

 # camcontrol rescan all
 Re-scan of bus 0 was successful
 Re-scan of bus 1 was successful
 Re-scan of bus 2 was successful
 Re-scan of bus 3 was successful

   The scanner should now appear in the SCSI devices list:

 # camcontrol devlist
 <IBM DDRS-34560 S97B>              at scbus0 target 5 lun 0 (pass0,da0)
 <IBM DDRS-34560 S97B>              at scbus0 target 6 lun 0 (pass1,da1)
 <AGFA SNAPSCAN 600 1.10>           at scbus1 target 2 lun 0 (pass3)
 <PHILIPS CDD3610 CD-R/RW 1.00>     at scbus2 target 0 lun 0 (pass2,cd0)

   Refer to scsi(4) and camcontrol(8) for more details about SCSI devices on
   FreeBSD.

  7.7.2. SANE Configuration

   The SANE system provides the access to the scanner via backends
   (graphics/sane-backends). Refer to
   http://www.sane-project.org/sane-supported-devices.html to determine which
   backend supports the scanner. A graphical scanning interface is provided
   by third party applications like Kooka (graphics/kooka) or XSane
   (graphics/xsane). SANE's backends are enough to test the scanner.

   To install the backends from binary package:

 # pkg install sane-backends

   Alternatively, to install from the Ports Collection

 # cd /usr/ports/graphics/sane-backends
 # make install clean

   After installing the graphics/sane-backends port or package, use
   sane-find-scanner to check the scanner detection by the SANE system:

 # sane-find-scanner -q
 found SCSI scanner "AGFA SNAPSCAN 600 1.10" at /dev/pass3

   The output should show the interface type of the scanner and the device
   node used to attach the scanner to the system. The vendor and the product
   model may or may not appear.

  Note:

   Some USB scanners require firmware to be loaded. Refer to
   sane-find-scanner(1) and sane(7) for details.

   Next, check if the scanner will be identified by a scanning frontend. The
   SANE backends include scanimage which can be used to list the devices and
   perform an image acquisition. Use -L to list the scanner devices. The
   first example is for a SCSI scanner and the second is for a USB scanner:

 # scanimage -L
 device `snapscan:/dev/pass3' is a AGFA SNAPSCAN 600 flatbed scanner
 # scanimage -L
 device 'epson2:libusb:000:002' is a Epson GT-8200 flatbed scanner

   In this second example, epson2 is the backend name and libusb:000:002
   means /dev/ugen0.2 is the device node used by the scanner.

   If scanimage is unable to identify the scanner, this message will appear:

 # scanimage -L

 No scanners were identified. If you were expecting something different,
 check that the scanner is plugged in, turned on and detected by the
 sane-find-scanner tool (if appropriate). Please read the documentation
 which came with this software (README, FAQ, manpages).

   If this happens, edit the backend configuration file in
   /usr/local/etc/sane.d/ and define the scanner device used. For example, if
   the undetected scanner model is an EPSON Perfection(R) 1650 and it uses
   the epson2 backend, edit /usr/local/etc/sane.d/epson2.conf. When editing,
   add a line specifying the interface and the device node used. In this
   case, add the following line:

 usb /dev/ugen0.2

   Save the edits and verify that the scanner is identified with the right
   backend name and the device node:

 # scanimage -L
 device 'epson2:libusb:000:002' is a Epson GT-8200 flatbed scanner

   Once scanimage -L sees the scanner, the configuration is complete and the
   scanner is now ready to use.

   While scanimage can be used to perform an image acquisition from the
   command line, it is often preferable to use a graphical interface to
   perform image scanning. Applications like Kooka or XSane are popular
   scanning frontends. They offer advanced features such as various scanning
   modes, color correction, and batch scans. XSane is also usable as a GIMP
   plugin.

  7.7.3. Scanner Permissions

   In order to have access to the scanner, a user needs read and write
   permissions to the device node used by the scanner. In the previous
   example, the USB scanner uses the device node /dev/ugen0.2 which is really
   a symlink to the real device node /dev/usb/0.2.0. The symlink and the
   device node are owned, respectively, by the wheel and operator groups.
   While adding the user to these groups will allow access to the scanner, it
   is considered insecure to add a user to wheel. A better solution is to
   create a group and make the scanner device accessible to members of this
   group.

   This example creates a group called usb:

 # pw groupadd usb

   Then, make the /dev/ugen0.2 symlink and the /dev/usb/0.2.0 device node
   accessible to the usb group with write permissions of 0660 or 0664 by
   adding the following lines to /etc/devfs.rules:

 [system=5]
 add path ugen0.2 mode 0660 group usb
 add path usb/0.2.0 mode 0666 group usb

  Note:

   It happens the device node changes with the addition or removal of
   devices, so one may want to give access to all USB devices using this
   ruleset instead:

 [system=5]
 add path 'ugen*' mode 0660 group usb
 add path 'usb/*' mode 0666 group usb

   Refer to devfs.rules(5) for more information about this file.

   Next, enable the ruleset in /etc/rc.conf:

 devfs_system_ruleset="system"

   And, restart the devfs(8) system:

 # service devfs restart

   Finally, add the users to usb in order to allow access to the scanner:

 # pw groupmod usb -m joe

   For more details refer to pw(8).

Chapter 8. Configuring the FreeBSD Kernel

   Table of Contents

   8.1. Synopsis

   8.2. Why Build a Custom Kernel?

   8.3. Finding the System Hardware

   8.4. The Configuration File

   8.5. Building and Installing a Custom Kernel

   8.6. If Something Goes Wrong

8.1. Synopsis

   The kernel is the core of the FreeBSD operating system. It is responsible
   for managing memory, enforcing security controls, networking, disk access,
   and much more. While much of FreeBSD is dynamically configurable, it is
   still occasionally necessary to configure and compile a custom kernel.

   After reading this chapter, you will know:

     * When to build a custom kernel.

     * How to take a hardware inventory.

     * How to customize a kernel configuration file.

     * How to use the kernel configuration file to create and build a new
       kernel.

     * How to install the new kernel.

     * How to troubleshoot if things go wrong.

   All of the commands listed in the examples in this chapter should be
   executed as root.

8.2. Why Build a Custom Kernel?

   Traditionally, FreeBSD used a monolithic kernel. The kernel was one large
   program, supported a fixed list of devices, and in order to change the
   kernel's behavior, one had to compile and then reboot into a new kernel.

   Today, most of the functionality in the FreeBSD kernel is contained in
   modules which can be dynamically loaded and unloaded from the kernel as
   necessary. This allows the running kernel to adapt immediately to new
   hardware and for new functionality to be brought into the kernel. This is
   known as a modular kernel.

   Occasionally, it is still necessary to perform static kernel
   configuration. Sometimes the needed functionality is so tied to the kernel
   that it can not be made dynamically loadable. Some security environments
   prevent the loading and unloading of kernel modules and require that only
   needed functionality is statically compiled into the kernel.

   Building a custom kernel is often a rite of passage for advanced BSD
   users. This process, while time consuming, can provide benefits to the
   FreeBSD system. Unlike the GENERIC kernel, which must support a wide range
   of hardware, a custom kernel can be stripped down to only provide support
   for that computer's hardware. This has a number of benefits, such as:

     * Faster boot time. Since the kernel will only probe the hardware on the
       system, the time it takes the system to boot can decrease.

     * Lower memory usage. A custom kernel often uses less memory than the
       GENERIC kernel by omitting unused features and device drivers. This is
       important because the kernel code remains resident in physical memory
       at all times, preventing that memory from being used by applications.
       For this reason, a custom kernel is useful on a system with a small
       amount of RAM.

     * Additional hardware support. A custom kernel can add support for
       devices which are not present in the GENERIC kernel.

   Before building a custom kernel, consider the reason for doing so. If
   there is a need for specific hardware support, it may already exist as a
   module.

   Kernel modules exist in /boot/kernel and may be dynamically loaded into
   the running kernel using kldload(8). Most kernel drivers have a loadable
   module and manual page. For example, the ath(4) wireless Ethernet driver
   has the following information in its manual page:

 Alternatively, to load the driver as a module at boot time, place the
 following line in loader.conf(5):

     if_ath_load="YES"

   Adding if_ath_load="YES" to /boot/loader.conf will load this module
   dynamically at boot time.

   In some cases, there is no associated module in /boot/kernel. This is
   mostly true for certain subsystems.

8.3. Finding the System Hardware

   Before editing the kernel configuration file, it is recommended to perform
   an inventory of the machine's hardware. On a dual-boot system, the
   inventory can be created from the other operating system. For example,
   Microsoft(R)'s Device Manager contains information about installed
   devices.

  Note:

   Some versions of Microsoft(R) Windows(R) have a System icon which can be
   used to access Device Manager.

   If FreeBSD is the only installed operating system, use dmesg(8) to
   determine the hardware that was found and listed during the boot probe.
   Most device drivers on FreeBSD have a manual page which lists the hardware
   supported by that driver. For example, the following lines indicate that
   the psm(4) driver found a mouse:

 psm0: <PS/2 Mouse> irq 12 on atkbdc0
 psm0: [GIANT-LOCKED]
 psm0: [ITHREAD]
 psm0: model Generic PS/2 mouse, device ID 0

   Since this hardware exists, this driver should not be removed from a
   custom kernel configuration file.

   If the output of dmesg does not display the results of the boot probe
   output, instead read the contents of /var/run/dmesg.boot.

   Another tool for finding hardware is pciconf(8), which provides more
   verbose output. For example:

 % pciconf -lv
 ath0@pci0:3:0:0:        class=0x020000 card=0x058a1014 chip=0x1014168c rev=0x01 hdr=0x00
     vendor     = 'Atheros Communications Inc.'
     device     = 'AR5212 Atheros AR5212 802.11abg wireless'
     class      = network
     subclass   = ethernet

   This output shows that the ath driver located a wireless Ethernet device.

   The -k flag of man(1) can be used to provide useful information. For
   example, it can be used to display a list of manual pages which contain a
   particular device brand or name:

 # man -k Atheros
 ath(4)                   - Atheros IEEE 802.11 wireless network driver
 ath_hal(4)               - Atheros Hardware Access Layer (HAL)

   Once the hardware inventory list is created, refer to it to ensure that
   drivers for installed hardware are not removed as the custom kernel
   configuration is edited.

8.4. The Configuration File

   In order to create a custom kernel configuration file and build a custom
   kernel, the full FreeBSD source tree must first be installed.

   If /usr/src/ does not exist or it is empty, source has not been installed.
   Source can be installed using Subversion and the instructions in
   Section A.3, "Using Subversion".

   Once source is installed, review the contents of /usr/src/sys. This
   directory contains a number of subdirectories, including those which
   represent the following supported architectures: amd64, i386, powerpc, and
   sparc64. Everything inside a particular architecture's directory deals
   with that architecture only and the rest of the code is machine
   independent code common to all platforms. Each supported architecture has
   a conf subdirectory which contains the GENERIC kernel configuration file
   for that architecture.

   Do not make edits to GENERIC. Instead, copy the file to a different name
   and make edits to the copy. The convention is to use a name with all
   capital letters. When maintaining multiple FreeBSD machines with different
   hardware, it is a good idea to name it after the machine's hostname. This
   example creates a copy, named MYKERNEL, of the GENERIC configuration file
   for the amd64 architecture:

 # cd /usr/src/sys/amd64/conf
 # cp GENERIC MYKERNEL

   MYKERNEL can now be customized with any ASCII text editor. The default
   editor is vi, though an easier editor for beginners, called ee, is also
   installed with FreeBSD.

   The format of the kernel configuration file is simple. Each line contains
   a keyword that represents a device or subsystem, an argument, and a brief
   description. Any text after a # is considered a comment and ignored. To
   remove kernel support for a device or subsystem, put a # at the beginning
   of the line representing that device or subsystem. Do not add or remove a
   # for any line that you do not understand.

  Warning:

   It is easy to remove support for a device or option and end up with a
   broken kernel. For example, if the ata(4) driver is removed from the
   kernel configuration file, a system using ATA disk drivers may not boot.
   When in doubt, just leave support in the kernel.

   In addition to the brief descriptions provided in this file, additional
   descriptions are contained in NOTES, which can be found in the same
   directory as GENERIC for that architecture. For architecture independent
   options, refer to /usr/src/sys/conf/NOTES.

  Tip:

   When finished customizing the kernel configuration file, save a backup
   copy to a location outside of /usr/src.

   Alternately, keep the kernel configuration file elsewhere and create a
   symbolic link to the file:

 # cd /usr/src/sys/amd64/conf
 # mkdir /root/kernels
 # cp GENERIC /root/kernels/MYKERNEL
 # ln -s /root/kernels/MYKERNEL

   An include directive is available for use in configuration files. This
   allows another configuration file to be included in the current one,
   making it easy to maintain small changes relative to an existing file. If
   only a small number of additional options or drivers are required, this
   allows a delta to be maintained with respect to GENERIC, as seen in this
   example:

 include GENERIC
 ident MYKERNEL

 options         IPFIREWALL
 options         DUMMYNET
 options         IPFIREWALL_DEFAULT_TO_ACCEPT
 options         IPDIVERT

   Using this method, the local configuration file expresses local
   differences from a GENERIC kernel. As upgrades are performed, new features
   added to GENERIC will also be added to the local kernel unless they are
   specifically prevented using nooptions or nodevice. A comprehensive list
   of configuration directives and their descriptions may be found in
   config(5).

  Note:

   To build a file which contains all available options, run the following
   command as root:

 # cd /usr/src/sys/arch/conf && make LINT

8.5. Building and Installing a Custom Kernel

   Once the edits to the custom configuration file have been saved, the
   source code for the kernel can be compiled using the following steps:

   Procedure 8.1. Building a Kernel
    1. Change to this directory:

 # cd /usr/src

    2. Compile the new kernel by specifying the name of the custom kernel
       configuration file:

 # make buildkernel KERNCONF=MYKERNEL

    3. Install the new kernel associated with the specified kernel
       configuration file. This command will copy the new kernel to
       /boot/kernel/kernel and save the old kernel to
       /boot/kernel.old/kernel:

 # make installkernel KERNCONF=MYKERNEL

    4. Shutdown the system and reboot into the new kernel. If something goes
       wrong, refer to The kernel does not boot.

   By default, when a custom kernel is compiled, all kernel modules are
   rebuilt. To update a kernel faster or to build only custom modules, edit
   /etc/make.conf before starting to build the kernel.

   For example, this variable specifies the list of modules to build instead
   of using the default of building all modules:

 MODULES_OVERRIDE = linux acpi

   Alternately, this variable lists which modules to exclude from the build
   process:

 WITHOUT_MODULES = linux acpi sound

   Additional variables are available. Refer to make.conf(5) for details.

8.6. If Something Goes Wrong

   There are four categories of trouble that can occur when building a custom
   kernel:

   config fails

           If config fails, it will print the line number that is incorrect.
           As an example, for the following message, make sure that line 17
           is typed correctly by comparing it to GENERIC or NOTES:

 config: line 17: syntax error

   make fails

           If make fails, it is usually due to an error in the kernel
           configuration file which is not severe enough for config to catch.
           Review the configuration, and if the problem is not apparent, send
           an email to the FreeBSD general questions mailing list which
           contains the kernel configuration file.

   The kernel does not boot

           If the new kernel does not boot or fails to recognize devices, do
           not panic! Fortunately, FreeBSD has an excellent mechanism for
           recovering from incompatible kernels. Simply choose the kernel to
           boot from at the FreeBSD boot loader. This can be accessed when
           the system boot menu appears by selecting the "Escape to a loader
           prompt" option. At the prompt, type boot kernel.old, or the name
           of any other kernel that is known to boot properly.

           After booting with a good kernel, check over the configuration
           file and try to build it again. One helpful resource is
           /var/log/messages which records the kernel messages from every
           successful boot. Also, dmesg(8) will print the kernel messages
           from the current boot.

  Note:

           When troubleshooting a kernel, make sure to keep a copy of
           GENERIC, or some other kernel that is known to work, as a
           different name that will not get erased on the next build. This is
           important because every time a new kernel is installed, kernel.old
           is overwritten with the last installed kernel, which may or may
           not be bootable. As soon as possible, move the working kernel by
           renaming the directory containing the good kernel:

 # mv /boot/kernel /boot/kernel.bad
 # mv /boot/kernel.good /boot/kernel

   The kernel works, but ps(1) does not

           If the kernel version differs from the one that the system
           utilities have been built with, for example, a kernel built from
           -CURRENT sources is installed on a -RELEASE system, many system
           status commands like ps(1) and vmstat(8) will not work. To fix
           this, recompile and install a world built with the same version of
           the source tree as the kernel. It is never a good idea to use a
           different version of the kernel than the rest of the operating
           system.

Chapter 9. Printing

   Originally contributed by Warren Block.
   Table of Contents

   9.1. Quick Start

   9.2. Printer Connections

   9.3. Common Page Description Languages

   9.4. Direct Printing

   9.5. LPD (Line Printer Daemon)

   9.6. Other Printing Systems

   Putting information on paper is a vital function, despite many attempts to
   eliminate it. Printing has two basic components. The data must be
   delivered to the printer, and must be in a form that the printer can
   understand.

9.1. Quick Start

   Basic printing can be set up quickly. The printer must be capable of
   printing plain ASCII text. For printing to other types of files, see
   Section 9.5.3, "Filters".

    1. Create a directory to store files while they are being printed:

 # mkdir -p /var/spool/lpd/lp
 # chown daemon:daemon /var/spool/lpd/lp
 # chmod 770 /var/spool/lpd/lp

    2. As root, create /etc/printcap with these contents:

 lp:\
         :lp=/dev/unlpt0:\  1
         :sh:\
         :mx#0:\
         :sd=/var/spool/lpd/lp:\
         :lf=/var/log/lpd-errs:

       1 This line is for a printer connected to a USB port.                  
                                                                              
         For a printer connected to a parallel or "printer" port, use:        
                                                                              
         :lp=/dev/lpt0:\                                                      
                                                                              
         For a printer connected directly to a network, use:                  
                                                                              
         :lp=:rm=network-printer-name:rp=raw:\                                
                                                                              
         Replace network-printer-name with the DNS host name of the network   
         printer.                                                             

    3. Enable lpd by editing /etc/rc.conf, adding this line:

 lpd_enable="YES"

       Start the service:

 # service lpd start
 Starting lpd.

    4. Print a test:

 # printf "1. This printer can print.\n2. This is the second line.\n" | lpr

  Tip:

       If both lines do not start at the left border, but "stairstep"
       instead, see Section 9.5.3.1, "Preventing Stairstepping on Plain Text
       Printers".

       Text files can now be printed with lpr. Give the filename on the
       command line, or pipe output directly into lpr.

 % lpr textfile.txt
 % ls -lh | lpr

9.2. Printer Connections

   Printers are connected to computer systems in a variety of ways. Small
   desktop printers are usually connected directly to a computer's USB port.
   Older printers are connected to a parallel or "printer" port. Some
   printers are directly connected to a network, making it easy for multiple
   computers to share them. A few printers use a rare serial port connection.

   FreeBSD can communicate with all of these types of printers.

   USB

           USB printers can be connected to any available USB port on the
           computer.

           When FreeBSD detects a USB printer, two device entries are
           created: /dev/ulpt0 and /dev/unlpt0. Data sent to either device
           will be relayed to the printer. After each print job, ulpt0 resets
           the USB port. Resetting the port can cause problems with some
           printers, so the unlpt0 device is usually used instead. unlpt0
           does not reset the USB port at all.

   Parallel (IEEE-1284)

           The parallel port device is /dev/lpt0. This device appears whether
           a printer is attached or not, it is not autodetected.

           Vendors have largely moved away from these "legacy" ports, and
           many computers no longer have them. Adapters can be used to
           connect a parallel printer to a USB port. With such an adapter,
           the printer can be treated as if it were actually a USB printer.
           Devices called print servers can also be used to connect parallel
           printers directly to a network.

   Serial (RS-232)

           Serial ports are another legacy port, rarely used for printers
           except in certain niche applications. Cables, connectors, and
           required wiring vary widely.

           For serial ports built into a motherboard, the serial device name
           is /dev/cuau0 or /dev/cuau1. Serial USB adapters can also be used,
           and these will appear as /dev/cuaU0.

           Several communication parameters must be known to communicate with
           a serial printer. The most important are baud rate or BPS (Bits
           Per Second) and parity. Values vary, but typical serial printers
           use a baud rate of 9600 and no parity.

   Network

           Network printers are connected directly to the local computer
           network.

           The DNS hostname of the printer must be known. If the printer is
           assigned a dynamic address by DHCP, DNS should be dynamically
           updated so that the host name always has the correct IP address.
           Network printers are often given static IP addresses to avoid this
           problem.

           Most network printers understand print jobs sent with the LPD
           protocol. A print queue name can also be specified. Some printers
           process data differently depending on which queue is used. For
           example, a raw queue prints the data unchanged, while the text
           queue adds carriage returns to plain text.

           Many network printers can also print data sent directly to port
           9100.

  9.2.1. Summary

   Wired network connections are usually the easiest to set up and give the
   fastest printing. For direct connection to the computer, USB is preferred
   for speed and simplicity. Parallel connections work but have limitations
   on cable length and speed. Serial connections are more difficult to
   configure. Cable wiring differs between models, and communication
   parameters like baud rate and parity bits must add to the complexity.
   Fortunately, serial printers are rare.

9.3. Common Page Description Languages

   Data sent to a printer must be in a language that the printer can
   understand. These languages are called Page Description Languages, or
   PDLs.

   ASCII

           Plain ASCII text is the simplest way to send data to a printer.
           Characters correspond one to one with what will be printed: an A
           in the data prints an A on the page. Very little formatting is
           available. There is no way to select a font or proportional
           spacing. The forced simplicity of plain ASCII means that text can
           be printed straight from the computer with little or no encoding
           or translation. The printed output corresponds directly with what
           was sent.

           Some inexpensive printers cannot print plain ASCII text. This
           makes them more difficult to set up, but it is usually still
           possible.

   PostScript(R)

           PostScript(R) is almost the opposite of ASCII. Rather than simple
           text, a PostScript(R) program is a set of instructions that draw
           the final document. Different fonts and graphics can be used.
           However, this power comes at a price. The program that draws the
           page must be written. Usually this program is generated by
           application software, so the process is invisible to the user.

           Inexpensive printers sometimes leave out PostScript(R)
           compatibility as a cost-saving measure.

   PCL (Printer Command Language)

           PCL is an extension of ASCII, adding escape sequences for
           formatting, font selection, and printing graphics. Many printers
           provide PCL5 support. Some support the newer PCL6 or PCLXL. These
           later versions are supersets of PCL5 and can provide faster
           printing.

   Host-Based

           Manufacturers can reduce the cost of a printer by giving it a
           simple processor and very little memory. These printers are not
           capable of printing plain text. Instead, bitmaps of text and
           graphics are drawn by a driver on the host computer and then sent
           to the printer. These are called host-based printers.

           Communication between the driver and a host-based printer is often
           through proprietary or undocumented protocols, making them
           functional only on the most common operating systems.

  9.3.1. Converting PostScript(R) to Other PDLs

   Many applications from the Ports Collection and FreeBSD utilities produce
   PostScript(R) output. This table shows the utilities available to convert
   that into other common PDLs:

   Table 9.1. Output PDLs

   Output PDL    Generated By            Notes                                
   PCL or PCL5   print/ghostscript9-base -sDEVICE=ljet4 for monochrome,       
                                         -sDEVICE=cljet5 for color            
   PCLXL or PCL6 print/ghostscript9-base -sDEVICE=pxlmono for monochrome,     
                                         -sDEVICE=pxlcolor for color          
   ESC/P2        print/ghostscript9-base -sDEVICE=uniprint                    
   XQX           print/foo2zjs                                                

  9.3.2. Summary

   For the easiest printing, choose a printer that supports PostScript(R).
   Printers that support PCL are the next preferred. With
   print/ghostscript9-base, these printers can be used as if they understood
   PostScript(R) natively. Printers that support PostScript(R) or PCL
   directly almost always support direct printing of plain ASCII text files
   also.

   Line-based printers like typical inkjets usually do not support
   PostScript(R) or PCL. They often can print plain ASCII text files.
   print/ghostscript9-base supports the PDLs used by some of these printers.
   However, printing an entire graphic-based page on these printers is often
   very slow due to the large amount of data to be transferred and printed.

   Host-based printers are often more difficult to set up. Some cannot be
   used at all because of proprietary PDLs. Avoid these printers when
   possible.

   Descriptions of many PDLs can be found at
   http://www.undocprint.org/formats/page_description_languages. The
   particular PDL used by various models of printers can be found at
   http://www.openprinting.org/printers.

9.4. Direct Printing

   For occasional printing, files can be sent directly to a printer device
   without any setup. For example, a file called sample.txt can be sent to a
   USB printer:

 # cp sample.txt /dev/unlpt0

   Direct printing to network printers depends on the abilities of the
   printer, but most accept print jobs on port 9100, and nc(1) can be used
   with them. To print the same file to a printer with the DNS hostname of
   netlaser:

 # nc netlaser 9100 < sample.txt

9.5. LPD (Line Printer Daemon)

   Printing a file in the background is called spooling. A spooler allows the
   user to continue with other programs on the computer without waiting for
   the printer to slowly complete the print job.

   FreeBSD includes a spooler called lpd(8). Print jobs are submitted with
   lpr(1).

  9.5.1. Initial Setup

   A directory for storing print jobs is created, ownership is set, and the
   permissions are set to prevent other users from viewing the contents of
   those files:

 # mkdir -p /var/spool/lpd/lp
 # chown daemon:daemon /var/spool/lpd/lp
 # chmod 770 /var/spool/lpd/lp

   Printers are defined in /etc/printcap. An entry for each printer includes
   details like a name, the port where it is attached, and various other
   settings. Create /etc/printcap with these contents:

 lp:\                            1
         :lp=/dev/unlpt0:\       2
         :sh:\                   3
         :mx#0:\                 4
         :sd=/var/spool/lpd/lp:\ 5
         :lf=/var/log/lpd-errs:  6

   1 The name of this printer. lpr(1) sends print jobs to the lp printer      
     unless another printer is specified with -P, so the default printer      
     should be named lp.                                                      
   2 The device where the printer is connected. Replace this line with the    
     appropriate one for the connection type shown here.                      
                                                                              
     +----------------------------------------------------------------------+ 
     | Connection Type |           Device Entry in /etc/printcap            | 
     |-----------------+----------------------------------------------------| 
     |                 |:lp=/dev/unlpt0:\                                   | 
     |                 |                                                    | 
     | USB             | This is the non-resetting USB printer device. If   | 
     |                 | problems are experienced, use ulpt0 instead, which | 
     |                 | resets the USB port on each use.                   | 
     |-----------------+----------------------------------------------------| 
     | Parallel        |:lp=/dev/lpt0:\                                     | 
     |-----------------+----------------------------------------------------| 
     |                 | For a printer supporting the LPD protocol:         | 
     |                 |                                                    | 
     |                 |:lp=:rm=network-printer-name:rp=raw:\               | 
     |                 |                                                    | 
     | Network         | For printers supporting port 9100 printing:        | 
     |                 |                                                    | 
     |                 |:lp=9100@network-printer-name:\                     | 
     |                 |                                                    | 
     |                 | For both types, replace network-printer-name with  | 
     |                 | the DNS host name of the network printer.          | 
     |-----------------+----------------------------------------------------| 
     |                 |:lp=/dev/cuau0:br=9600:pa=none:\                    | 
     |                 |                                                    | 
     | Serial          | These values are for a typical serial printer      | 
     |                 | connected to a motherboard serial port. The baud   | 
     |                 | rate is 9600, and no parity is used.               | 
     +----------------------------------------------------------------------+ 
   3 Suppress the printing of a header page at the start of a print job.      
   4 Do not limit the maximum size of a print job.                            
   5 The path to the spooling directory for this printer. Each printer uses   
     its own spooling directory.                                              
   6 The log file where errors on this printer will be reported.              

   After creating /etc/printcap, use chkprintcap(8) to test it for errors:

 # chkprintcap

   Fix any reported problems before continuing.

   Enable lpd(8) in /etc/rc.conf:

 lpd_enable="YES"

   Start the service:

 # service lpd start

  9.5.2. Printing with lpr(1)

   Documents are sent to the printer with lpr. A file to be printed can be
   named on the command line or piped into lpr. These two commands are
   equivalent, sending the contents of doc.txt to the default printer:

 % lpr doc.txt
 % cat doc.txt | lpr

   Printers can be selected with -P. To print to a printer called laser:

 % lpr -Plaser doc.txt

  9.5.3. Filters

   The examples shown so far have sent the contents of a text file directly
   to the printer. As long as the printer understands the content of those
   files, output will be printed correctly.

   Some printers are not capable of printing plain text, and the input file
   might not even be plain text.

   Filters allow files to be translated or processed. The typical use is to
   translate one type of input, like plain text, into a form that the printer
   can understand, like PostScript(R) or PCL. Filters can also be used to
   provide additional features, like adding page numbers or highlighting
   source code to make it easier to read.

   The filters discussed here are input filters or text filters. These
   filters convert the incoming file into different forms. Use su(1) to
   become root before creating the files.

   Filters are specified in /etc/printcap with the if= identifier. To use
   /usr/local/libexec/lf2crlf as a filter, modify /etc/printcap like this:

 lp:\
         :lp=/dev/unlpt0:\
         :sh:\
         :mx#0:\
         :sd=/var/spool/lpd/lp:\
         :if=/usr/local/libexec/lf2crlf:\   1
         :lf=/var/log/lpd-errs:

   1   if= identifies the input filter that will be used on incoming text.  

  Tip:

   The backslash line continuation characters at the end of the lines in
   printcap entries reveal that an entry for a printer is really just one
   long line with entries delimited by colon characters. An earlier example
   can be rewritten as a single less-readable line:

 lp:lp=/dev/unlpt0:sh:mx#0:sd=/var/spool/lpd/lp:if=/usr/local/libexec/lf2crlf:lf=/var/log/lpd-errs:

    9.5.3.1. Preventing Stairstepping on Plain Text Printers

   Typical FreeBSD text files contain only a single line feed character at
   the end of each line. These lines will "stairstep" on a standard printer:

 A printed file looks
                     like the steps of a staircase
                                                  scattered by the wind

   A filter can convert the newline characters into carriage returns and
   newlines. The carriage returns make the printer return to the left after
   each line. Create /usr/local/libexec/lf2crlf with these contents:

 #!/bin/sh
 CR=$'\r'
 /usr/bin/sed -e "s/$/${CR}/g"

   Set the permissions and make it executable:

 # chmod 555 /usr/local/libexec/lf2crlf

   Modify /etc/printcap to use the new filter:

 :if=/usr/local/libexec/lf2crlf:\

   Test the filter by printing the same plain text file. The carriage returns
   will cause each line to start at the left side of the page.

    9.5.3.2. Fancy Plain Text on PostScript(R) Printers with print/enscript

   GNU Enscript converts plain text files into nicely-formatted PostScript(R)
   for printing on PostScript(R) printers. It adds page numbers, wraps long
   lines, and provides numerous other features to make printed text files
   easier to read. Depending on the local paper size, install either
   print/enscript-letter or print/enscript-a4 from the Ports Collection.

   Create /usr/local/libexec/enscript with these contents:

 #!/bin/sh
 /usr/local/bin/enscript -o -

   Set the permissions and make it executable:

 # chmod 555 /usr/local/libexec/enscript

   Modify /etc/printcap to use the new filter:

 :if=/usr/local/libexec/enscript:\

   Test the filter by printing a plain text file.

    9.5.3.3. Printing PostScript(R) to PCL Printers

   Many programs produce PostScript(R) documents. However, inexpensive
   printers often only understand plain text or PCL. This filter converts
   PostScript(R) files to PCL before sending them to the printer.

   Install the Ghostscript PostScript(R) interpreter,
   print/ghostscript9-base, from the Ports Collection.

   Create /usr/local/libexec/ps2pcl with these contents:

 #!/bin/sh
 /usr/local/bin/gs -dSAFER -dNOPAUSE -dBATCH -q -sDEVICE=ljet4 -sOutputFile=- -

   Set the permissions and make it executable:

 # chmod 555 /usr/local/libexec/ps2pcl

   PostScript(R) input sent to this script will be rendered and converted to
   PCL before being sent on to the printer.

   Modify /etc/printcap to use this new input filter:

 :if=/usr/local/libexec/ps2pcl:\

   Test the filter by sending a small PostScript(R) program to it:

 % printf "%%\!PS \n /Helvetica findfont 18 scalefont setfont \
 72 432 moveto (PostScript printing successful.) show showpage \004" | lpr

    9.5.3.4. Smart Filters

   A filter that detects the type of input and automatically converts it to
   the correct format for the printer can be very convenient. The first two
   characters of a PostScript(R) file are usually %!. A filter can detect
   those two characters. PostScript(R) files can be sent on to a
   PostScript(R) printer unchanged. Text files can be converted to
   PostScript(R) with Enscript as shown earlier. Create
   /usr/local/libexec/psif with these contents:

 #!/bin/sh
 #
 #  psif - Print PostScript or plain text on a PostScript printer
 #
 IFS="" read -r first_line
 first_two_chars=`expr "$first_line" : '\(..\)'`

 case "$first_two_chars" in
 %!)
     # %! : PostScript job, print it.
     echo "$first_line" && cat && exit 0
     exit 2
     ;;
 *)
     # otherwise, format with enscript
     ( echo "$first_line"; cat ) | /usr/local/bin/enscript -o - && exit 0
     exit 2
     ;;
 esac

   Set the permissions and make it executable:

 # chmod 555 /usr/local/libexec/psif

   Modify /etc/printcap to use this new input filter:

 :if=/usr/local/libexec/psif:\

   Test the filter by printing PostScript(R) and plain text files.

    9.5.3.5. Other Smart Filters

   Writing a filter that detects many different types of input and formats
   them correctly is challenging. print/apsfilter from the Ports Collection
   is a smart "magic" filter that detects dozens of file types and
   automatically converts them to the PDL understood by the printer. See
   http://www.apsfilter.org for more details.

  9.5.4. Multiple Queues

   The entries in /etc/printcap are really definitions of queues. There can
   be more than one queue for a single printer. When combined with filters,
   multiple queues provide users more control over how their jobs are
   printed.

   As an example, consider a networked PostScript(R) laser printer in an
   office. Most users want to print plain text, but a few advanced users want
   to be able to print PostScript(R) files directly. Two entries can be
   created for the same printer in /etc/printcap:

 textprinter:\
         :lp=9100@officelaser:\
         :sh:\
         :mx#0:\
         :sd=/var/spool/lpd/textprinter:\
         :if=/usr/local/libexec/enscript:\
         :lf=/var/log/lpd-errs:

 psprinter:\
         :lp=9100@officelaser:\
         :sh:\
         :mx#0:\
         :sd=/var/spool/lpd/psprinter:\
         :lf=/var/log/lpd-errs:

   Documents sent to textprinter will be formatted by the
   /usr/local/libexec/enscript filter shown in an earlier example. Advanced
   users can print PostScript(R) files on psprinter, where no filtering is
   done.

   This multiple queue technique can be used to provide direct access to all
   kinds of printer features. A printer with a duplexer could use two queues,
   one for ordinary single-sided printing, and one with a filter that sends
   the command sequence to enable double-sided printing and then sends the
   incoming file.

  9.5.5. Monitoring and Controlling Printing

   Several utilities are available to monitor print jobs and check and
   control printer operation.

    9.5.5.1. lpq(1)

   lpq(1) shows the status of a user's print jobs. Print jobs from other
   users are not shown.

   Show the current user's pending jobs on a single printer:

 % lpq -Plp
 Rank   Owner      Job  Files                                 Total Size
 1st    jsmith     0    (standard input)                      12792 bytes

   Show the current user's pending jobs on all printers:

 % lpq -a
 lp:
 Rank   Owner      Job  Files                                 Total Size
 1st    jsmith     1    (standard input)                      27320 bytes

 laser:
 Rank   Owner      Job  Files                                 Total Size
 1st    jsmith     287  (standard input)                      22443 bytes

    9.5.5.2. lprm(1)

   lprm(1) is used to remove print jobs. Normal users are only allowed to
   remove their own jobs. root can remove any or all jobs.

   Remove all pending jobs from a printer:

 # lprm -Plp -
 dfA002smithy dequeued
 cfA002smithy dequeued
 dfA003smithy dequeued
 cfA003smithy dequeued
 dfA004smithy dequeued
 cfA004smithy dequeued

   Remove a single job from a printer. lpq(1) is used to find the job number.

 % lpq
 Rank   Owner      Job  Files                                 Total Size
 1st    jsmith     5    (standard input)                      12188 bytes
 % lprm -Plp 5
 dfA005smithy dequeued
 cfA005smithy dequeued

    9.5.5.3. lpc(8)

   lpc(8) is used to check and modify printer status. lpc is followed by a
   command and an optional printer name. all can be used instead of a
   specific printer name, and the command will be applied to all printers.
   Normal users can view status with lpc(8). Only root can use commands which
   modify printer status.

   Show the status of all printers:

 % lpc status all
 lp:
         queuing is enabled
         printing is enabled
         1 entry in spool area
         printer idle
 laser:
         queuing is enabled
         printing is enabled
         1 entry in spool area
         waiting for laser to come up

   Prevent a printer from accepting new jobs, then begin accepting new jobs
   again:

 # lpc disable lp
 lp:
         queuing disabled
 # lpc enable lp
 lp:
         queuing enabled

   Stop printing, but continue to accept new jobs. Then begin printing again:

 # lpc stop lp
 lp:
         printing disabled
 # lpc start lp
 lp:
         printing enabled
         daemon started

   Restart a printer after some error condition:

 # lpc restart lp
 lp:
         no daemon to abort
         printing enabled
         daemon restarted

   Turn the print queue off and disable printing, with a message to explain
   the problem to users:

 # lpc down lp Repair parts will arrive on Monday
 lp:
         printer and queuing disabled
         status message is now: Repair parts will arrive on Monday

   Re-enable a printer that is down:

 # lpc up lp
 lp:
         printing enabled
         daemon started

   See lpc(8) for more commands and options.

  9.5.6. Shared Printers

   Printers are often shared by multiple users in businesses and schools.
   Additional features are provided to make sharing printers more convenient.

    9.5.6.1. Aliases

   The printer name is set in the first line of the entry in /etc/printcap.
   Additional names, or aliases, can be added after that name. Aliases are
   separated from the name and each other by vertical bars:

 lp|repairsprinter|salesprinter:\

   Aliases can be used in place of the printer name. For example, users in
   the Sales department print to their printer with

 % lpr -Psalesprinter sales-report.txt

   Users in the Repairs department print to their printer with

 % lpr -Prepairsprinter repairs-report.txt

   All of the documents print on that single printer. When the Sales
   department grows enough to need their own printer, the alias can be
   removed from the shared printer entry and used as the name of a new
   printer. Users in both departments continue to use the same commands, but
   the Sales documents are sent to the new printer.

    9.5.6.2. Header Pages

   It can be difficult for users to locate their documents in the stack of
   pages produced by a busy shared printer. Header pages were created to
   solve this problem. A header page with the user name and document name is
   printed before each print job. These pages are also sometimes called
   banner or separator pages.

   Enabling header pages differs depending on whether the printer is
   connected directly to the computer with a USB, parallel, or serial cable,
   or is connected remotely over a network.

   Header pages on directly-connected printers are enabled by removing the
   :sh:\ (Suppress Header) line from the entry in /etc/printcap. These header
   pages only use line feed characters for new lines. Some printers will need
   the /usr/share/examples/printing/hpif filter to prevent stairstepped text.
   The filter configures PCL printers to print both carriage returns and line
   feeds when a line feed is received.

   Header pages for network printers must be configured on the printer
   itself. Header page entries in /etc/printcap are ignored. Settings are
   usually available from the printer front panel or a configuration web page
   accessible with a web browser.

  9.5.7. References

   Example files: /usr/share/examples/printing/.

   The 4.3BSD Line Printer Spooler Manual,
   /usr/share/doc/smm/07.lpd/paper.ascii.gz.

   Manual pages: printcap(5), lpd(8), lpr(1), lpc(8), lprm(1), lpq(1).

9.6. Other Printing Systems

   Several other printing systems are available in addition to the built-in
   lpd(8). These systems offer support for other protocols or additional
   features.

  9.6.1. CUPS (Common UNIX(R) Printing System)

   CUPS is a popular printing system available on many operating systems.
   Using CUPS on FreeBSD is documented in a separate
   article:../../../../doc/en_US.ISO8859-1/articles/cups

  9.6.2. HPLIP

   Hewlett Packard provides a printing system that supports many of their
   inkjet and laser printers. The port is print/hplip. The main web page is
   at http://hplipopensource.com/hplip-web/index.html. The port handles all
   the installation details on FreeBSD. Configuration information is shown at
   http://hplipopensource.com/hplip-web/install/manual/hp_setup.html.

  9.6.3. LPRng

   LPRng was developed as an enhanced alternative to lpd(8). The port is
   sysutils/LPRng. For details and documentation, see http://www.lprng.com/.

Chapter 10. Linux(R) Binary Compatibility

   Restructured and parts updated by Jim Mock.
   Originally contributed by Brian N. Handy and Rich Murphey.
   Table of Contents

   10.1. Synopsis

   10.2. Configuring Linux(R) Binary Compatibility

   10.3. Advanced Topics

10.1. Synopsis

   FreeBSD provides binary compatibility with Linux(R), allowing users to
   install and run most Linux(R) binaries on a FreeBSD system without having
   to first modify the binary. It has even been reported that, in some
   situations, Linux(R) binaries perform better on FreeBSD than they do on
   Linux(R).

   However, some Linux(R)-specific operating system features are not
   supported under FreeBSD. For example, Linux(R) binaries will not work on
   FreeBSD if they overly use i386(TM) specific calls, such as enabling
   virtual 8086 mode.

  Note:

   Support for 64-bit binary compatibility with Linux(R) was added in
   FreeBSD 10.3.

   After reading this chapter, you will know:

     * How to enable Linux(R) binary compatibility on a FreeBSD system.

     * How to install additional Linux(R) shared libraries.

     * How to install Linux(R) applications on a FreeBSD system.

     * The implementation details of Linux(R) compatibility in FreeBSD.

   Before reading this chapter, you should:

     * Know how to install additional third-party software.

10.2. Configuring Linux(R) Binary Compatibility

   By default, Linux(R) libraries are not installed and Linux(R) binary
   compatibility is not enabled. Linux(R) libraries can either be installed
   manually or from the FreeBSD Ports Collection.

   Before attempting to build the port, load the Linux(R) kernel module,
   otherwise the build will fail:

 # kldload linux

   For 64-bit compatibility:

 # kldload linux64

   To verify that the module is loaded:

 % kldstat
       Id Refs Address    Size     Name
       1    2 0xc0100000 16bdb8   kernel
       7    1 0xc24db000 d000     linux.ko

   The emulators/linux_base-c7 package or port is the easiest way to install
   a base set of Linux(R) libraries and binaries on a FreeBSD system. To
   install the port:

 # pkg install emulators/linux_base-c7

   For Linux(R) compatibility to be enabled at boot time, add this line to
   /etc/rc.conf:

 linux_enable="YES"

   On 64-bit machines, /etc/rc.d/abi will automatically load the module for
   64-bit emulation.

   Since the Linux(R) binary compatibility layer has gained support for
   running both 32- and 64-bit Linux(R) binaries (on 64-bit x86 hosts), it is
   no longer possible to link the emulation functionality statically into a
   custom kernel.

  10.2.1. Installing Additional Libraries Manually

   If a Linux(R) application complains about missing shared libraries after
   configuring Linux(R) binary compatibility, determine which shared
   libraries the Linux(R) binary needs and install them manually.

   From a Linux(R) system, ldd can be used to determine which shared
   libraries the application needs. For example, to check which shared
   libraries linuxdoom needs, run this command from a Linux(R) system that
   has Doom installed:

 % ldd linuxdoom
 libXt.so.3 (DLL Jump 3.1) => /usr/X11/lib/libXt.so.3.1.0
 libX11.so.3 (DLL Jump 3.1) => /usr/X11/lib/libX11.so.3.1.0
 libc.so.4 (DLL Jump 4.5pl26) => /lib/libc.so.4.6.29

   Then, copy all the files in the last column of the output from the
   Linux(R) system into /compat/linux on the FreeBSD system. Once copied,
   create symbolic links to the names in the first column. This example will
   result in the following files on the FreeBSD system:

 /compat/linux/usr/X11/lib/libXt.so.3.1.0
 /compat/linux/usr/X11/lib/libXt.so.3 -> libXt.so.3.1.0
 /compat/linux/usr/X11/lib/libX11.so.3.1.0
 /compat/linux/usr/X11/lib/libX11.so.3 -> libX11.so.3.1.0
 /compat/linux/lib/libc.so.4.6.29
 /compat/linux/lib/libc.so.4 -> libc.so.4.6.29

   If a Linux(R) shared library already exists with a matching major revision
   number to the first column of the ldd output, it does not need to be
   copied to the file named in the last column, as the existing library
   should work. It is advisable to copy the shared library if it is a newer
   version, though. The old one can be removed, as long as the symbolic link
   points to the new one.

   For example, these libraries already exist on the FreeBSD system:

 /compat/linux/lib/libc.so.4.6.27
 /compat/linux/lib/libc.so.4 -> libc.so.4.6.27

   and ldd indicates that a binary requires a later version:

 libc.so.4 (DLL Jump 4.5pl26) -> libc.so.4.6.29

   Since the existing library is only one or two versions out of date in the
   last digit, the program should still work with the slightly older version.
   However, it is safe to replace the existing libc.so with the newer
   version:

 /compat/linux/lib/libc.so.4.6.29
 /compat/linux/lib/libc.so.4 -> libc.so.4.6.29

   Generally, one will need to look for the shared libraries that Linux(R)
   binaries depend on only the first few times that a Linux(R) program is
   installed on FreeBSD. After a while, there will be a sufficient set of
   Linux(R) shared libraries on the system to be able to run newly installed
   Linux(R) binaries without any extra work.

  10.2.2. Installing Linux(R) ELF Binaries

   ELF binaries sometimes require an extra step. When an unbranded ELF binary
   is executed, it will generate an error message:

 % ./my-linux-elf-binary
 ELF binary type not known
 Abort

   To help the FreeBSD kernel distinguish between a FreeBSD ELF binary and a
   Linux(R) binary, use brandelf(1):

 % brandelf -t Linux my-linux-elf-binary

   Since the GNU toolchain places the appropriate branding information into
   ELF binaries automatically, this step is usually not necessary.

  10.2.3. Installing a Linux(R) RPM Based Application

   To install a Linux(R) RPM-based application, first install the
   archivers/rpm4 package or port. Once installed, root can use this command
   to install a .rpm:

 # cd /compat/linux
 # rpm2cpio < /path/to/linux.archive.rpm | cpio -id

   If necessary, brandelf the installed ELF binaries. Note that this will
   prevent a clean uninstall.

  10.2.4. Configuring the Hostname Resolver

   If DNS does not work or this error appears:

 resolv+: "bind" is an invalid keyword resolv+:
 "hosts" is an invalid keyword

   configure /compat/linux/etc/host.conf as follows:

 order hosts, bind
 multi on

   This specifies that /etc/hosts is searched first and DNS is searched
   second. When /compat/linux/etc/host.conf does not exist, Linux(R)
   applications use /etc/host.conf and complain about the incompatible
   FreeBSD syntax. Remove bind if a name server is not configured using
   /etc/resolv.conf.

10.3. Advanced Topics

   This section describes how Linux(R) binary compatibility works and is
   based on an email written to FreeBSD chat mailing list by Terry Lambert
   <tlambert@primenet.com> (Message ID:
   <199906020108.SAA07001@usr09.primenet.com>).

   FreeBSD has an abstraction called an "execution class loader". This is a
   wedge into the execve(2) system call.

   Historically, the UNIX(R) loader examined the magic number (generally the
   first 4 or 8 bytes of the file) to see if it was a binary known to the
   system, and if so, invoked the binary loader.

   If it was not the binary type for the system, the execve(2) call returned
   a failure, and the shell attempted to start executing it as shell
   commands. The assumption was a default of "whatever the current shell is".

   Later, a hack was made for sh(1) to examine the first two characters, and
   if they were :\n, it invoked the csh(1) shell instead.

   FreeBSD has a list of loaders, instead of a single loader, with a fallback
   to the #! loader for running shell interpreters or shell scripts.

   For the Linux(R) ABI support, FreeBSD sees the magic number as an ELF
   binary. The ELF loader looks for a specialized brand, which is a comment
   section in the ELF image, and which is not present on SVR4/Solaris(TM) ELF
   binaries.

   For Linux(R) binaries to function, they must be branded as type Linux
   using brandelf(1):

 # brandelf -t Linux file

   When the ELF loader sees the Linux brand, the loader replaces a pointer in
   the proc structure. All system calls are indexed through this pointer. In
   addition, the process is flagged for special handling of the trap vector
   for the signal trampoline code, and several other (minor) fix-ups that are
   handled by the Linux(R) kernel module.

   The Linux(R) system call vector contains, among other things, a list of
   sysent[] entries whose addresses reside in the kernel module.

   When a system call is called by the Linux(R) binary, the trap code
   dereferences the system call function pointer off the proc structure, and
   gets the Linux(R), not the FreeBSD, system call entry points.

   Linux(R) mode dynamically reroots lookups. This is, in effect, equivalent
   to union to file system mounts. First, an attempt is made to lookup the
   file in /compat/linux/original-path. If that fails, the lookup is done in
   /original-path. This makes sure that binaries that require other binaries
   can run. For example, the Linux(R) toolchain can all run under Linux(R)
   ABI support. It also means that the Linux(R) binaries can load and execute
   FreeBSD binaries, if there are no corresponding Linux(R) binaries present,
   and that a uname(1) command can be placed in the /compat/linux directory
   tree to ensure that the Linux(R) binaries cannot tell they are not running
   on Linux(R).

   In effect, there is a Linux(R) kernel in the FreeBSD kernel. The various
   underlying functions that implement all of the services provided by the
   kernel are identical to both the FreeBSD system call table entries, and
   the Linux(R) system call table entries: file system operations, virtual
   memory operations, signal delivery, and System V IPC. The only difference
   is that FreeBSD binaries get the FreeBSD glue functions, and Linux(R)
   binaries get the Linux(R) glue functions. The FreeBSD glue functions are
   statically linked into the kernel, and the Linux(R) glue functions can be
   statically linked, or they can be accessed via a kernel module.

   Technically, this is not really emulation, it is an ABI implementation. It
   is sometimes called "Linux(R) emulation" because the implementation was
   done at a time when there was no other word to describe what was going on.
   Saying that FreeBSD ran Linux(R) binaries was not true, since the code was
   not compiled in.

Chapter 11. WINE

   Contributed by Aaron Peters.
   DocBook markup edits by Benedict Reuschling.
   Table of Contents

   11.1. Synopsis

   11.2. WINE Overview & Concepts

   11.3. Installing WINE on FreeBSD

   11.4. Running a First WINE Program on FreeBSD

   11.5. Configuring WINE Installation

   11.6. WINE Management GUIs

   11.7. WINE in Multi-User FreeBSD Installations

   11.8. WINE on FreeBSD FAQ

11.1. Synopsis

   WINE, which stands for Wine Is Not an Emulator, is technically a software
   translation layer. It enables to install and run some software written for
   Windows(R) on FreeBSD (and other) systems.

   It operates by intercepting system calls, or requests from the software to
   the operating system, and translating them from Windows(R) calls to calls
   that FreeBSD understands. It will also translate any responses as needed
   into what the Windows(R) software is expecting. So in some ways, it
   emulates a Windows(R) environment, in that it provides many of the
   resources Windows(R) applications are expecting.

   However, it is not an emulator in the traditional sense. Many of these
   solutions operate by constructing an entire other computer using software
   processes in place of hardware Virtualization (such as that provided by
   the emulators/qemu port) operates in this way. One of the benefits of this
   approach is the ability to install a full version of the OS in question to
   the emulator. It means that the environment will not look any different to
   applications than a real machine, and chances are good that everything
   will work on it. The downside to this approach is the fact that software
   acting as hardware is inherently slower than actual hardware. The computer
   built in software (called the guest) requires resources from the real
   machine (the host), and holds on to those resources for as long as it is
   running.

   The WINE Project, on the other hand, is much lighter on system's
   resources. It will translate system calls on the fly, so while it is
   difficult to be as fast as a real Windows(R) computer, it can come very
   close. On the other hand, WINE is trying to keep up with a moving target
   in terms of all the different system calls and other functionality it
   needs to support. As a result there may be applications that do not work
   as expected on WINE, will not work at all, or will not even install to
   begin with.

   At the end of the day, WINE provides another option to try to get a
   particular Windows(R) software program running on FreeBSD. It can always
   serve as the first option which, if successful, offers a good experience
   without unnecessarily depleting the host FreeBSD system's resources.

   This chapter will describe:

     * How to install WINE on a FreeBSD system.

     * How WINE operates, and how it is different from other alternatives
       like virtualizaton.

     * How to fine-tune WINE to the specific needs of some applications.

     * How to install GUI helpers for WINE.

     * Common tips and solutions for on FreeBSD.

     * Considerations for WINE on FreeBSD in terms of the multi-user
       environment.

   Before reading this chapter, it will be useful to:

     * Understand the basics of UNIX(R) and FreeBSD.

     * Know how to install FreeBSD.

     * Know how to set up a network connection.

     * Know how to install additional third-party software.

11.2. WINE Overview & Concepts

   WINE is a complex system, so before running it on a FreeBSD system it is
   worth gaining an understanding of what it is and how it works.

  11.2.1. What is WINE?

   As mentioned in the Synopsis for this chapter, WINE is a compatibility
   layer that allows Windows(R) applications to run on other operating
   systems. In theory, it means these programs should run on systems like
   FreeBSD, macOS, and Android.

   When WINE runs a Windows(R) executable, two things occur:

     * Firstly, WINE implements an environment that mimics that of various
       versions of Windows(R). For example, if an application requests access
       to a resource such as RAM, WINE has a memory interface that looks and
       acts (as far as the application is concerned) like Windows(R).

     * Then, once that application makes use of that interface, WINE takes
       the incoming request for space in memory and translates it to
       something compatible with the host system. In the same way when the
       application retrieves that data, WINE facilitates fetching it from the
       host system and passing it back to the Windows(R) application.

  11.2.2. WINE and the FreeBSD System

   Installing WINE on a FreeBSD system will entail a few different
   components:

     * FreeBSD applications for tasks such as running the Windows(R)
       executables, configuring the WINE sub-system, or compiling programs
       with WINE support.

     * A large number of libraries that implement the core functions of
       Windows(R) (for example /lib/wine/api-ms-core-memory-l1-1-1.dll.so,
       which is part of the aforementioned memory interface).

     * A number of Windows(R) executables, which are (or mimic) common
       utilities (such as /lib/wine/notepad.exe.so, which provides the
       standard Windows(R) text editor).

     * Additional Windows(R) assets, in particular fonts (like the Tahoma
       font, which is stored in share/wine/fonts/tahoma.ttf in the install
       root).

  11.2.3. Graphical Versus Text Mode/Terminal Programs in WINE

   As an operating system where terminal utilities are "first-class
   citizens," it is natural to assume that WINE will contain extensive
   support for text-mode program. However, the majority of applications for
   Windows(R), especially the most popular ones, are designed with a
   graphical user interface (GUI) in mind. Therefore, WINE's utilities are
   designed by default to launch graphical programs.

   However, there are three methods available to run these so-called Console
   User Interface (CUI) programs:

     * The Bare Streams approach will display the output directly to standard
       output.

     * The wineconsole utility can be used with either the user or curses
       backed to utilize some of the enhancements the WINE system provides
       for CUI applications.

   These approaches are described in greater detail on the WINE Wiki.

  11.2.4. WINE Derivative Projects

   WINE itself is a mature open source project, so it is little surprise it
   is used as the foundation of more complex solutions.

    11.2.4.1. Commercial WINE Implementations

   A number of companies have taken WINE and made it a core of their own,
   proprietary products (WINE's LGPL license permits this). Two of the most
   famous of these are as follows:

     * Codeweavers CrossOver

   This solution provides a simplified "one-click" installation of WINE,
   which contains additional enhancements and optimizations (although the
   company contributes many of these back upstream to the WINE project). One
   area of focus for Codeweavers is to make the most popular applications
   install and run smoothly.

   While the company once produced a native FreeBSD version of their
   CrossOver solution, it appears to have long been abandoned. While some
   resources (such as a dedicated forum) are still present, they also have
   seen no activity for some time.

     * Steam Proton

   Gaming company Steam also uses WINE to enable Windows(R) games to install
   and run on other systems. it is primary target is Linux-based systems,
   though some support exists for macOS as well.

   While Steam does not offer a native FreeBSD client,there are several
   options for using the Linux(R) client using FreeBSD's Linux Compatibility
   Layer.

    11.2.4.2. WINE Companion Programs

   In addition to proprietary offerings, other projects have released
   applications designed to work in tandem with the standard, open source
   version of WINE. The goals for these can range from making installation
   easier to offering easy ways to get popular software installed.

   These solutions are covered in greater detail in the later section on GUI
   frontends, and include the following:

     * winetricks

     * Homura

  11.2.5. Alternatives to WINE

   For FreeBSD users, some alternatives to using WINE are as follows:

     * Dual-Booting: A straightforward option is to run desired Windows(R)
       applications natively on that OS. This of course means existing
       FreeBSD in order to boot Windows(R), so this method is not feasible if
       access to programs in both systems is required simultaneously.

     * Virtual Machines: Virtual Machines (VMs), as mentioned earlier in this
       chapter, are software processes that emulate full sets of hardware, on
       which additional operating systems (including Windows(R)) can be
       installed and run. Modern tools make VMs easy to create and manage,
       but this method comes at a cost. A good portion of the host systems
       resources must be allocated to each VM, and those resources cannot be
       reclaimed by the host as long as the VM is running. A few examples of
       VM managers include the open source solutions qemu, bhyve, and
       VirtualBox. See the chapter on Virtualization for more detail.

     * Remote Access: Like many other UNIX(R)-like systems, FreeBSD can run a
       variety of applications enabling users to remotely access Windows(R)
       computers and use their programs or data. In addtion to clients such
       as xrdp that connect to the standard Windows(R) Remote Desktop
       Protocol, other open source standards such as vnc can also be used
       (provided a compatible server is present on the other side).

11.3. Installing WINE on FreeBSD

   WINE can be installed via the pkg tool, or by compiling the port(s).

  11.3.1. WINE Prerequistes

   Before installing WINE itself, it is useful to have the following
   pre-requisites installed.

     * A GUI

   Most Windows(R) programs are expecting to have a graphical user interface
   available. If WINE is installed without one present, its dependencies will
   include the Wayland compositor, and so a GUI will be installed along with
   WINE. But it is useful to have the GUI of choice installed, configured,
   and working correctly before installing WINE.

     * wine-gecko

   The Windows(R) operating system has for some time had a default web
   browser pre-installed: Internet Explorer. As a result, some applications
   work under the assumption that there will always be something capable of
   displaying web pages. In order to provide this functionality, the WINE
   layer includes a web browser component using the Mozilla project's Gecko
   engine. When WINE is first launched it will offer to download and install
   this, and there are reasons users might want it do so (these will be
   covered in a later chapter). But they can also install it prior to
   installing WINE, or alongside the install of WINE proper.

   Install this package with the following:

 # pkg install wine-gecko

   Alternately, compile the port with the following:

 # cd /usr/ports/emulator/wine-gecko
 # make install

     * wine-mono

   This port installs the MONO framework, an open source implementation of
   Microsoft's .NET. Including this with the WINE installation will make it
   that much more likely that any applications written in .NET will install
   and run on the system.

   To install the package:

 # pkg install wine-mono

   To compile from the ports collection:

 # cd /usr/ports/emulator/wine-mono
 # make install

  11.3.2. Installing WINE via FreeBSD Package Repositories

   With the pre-requisites in place, install WINE via package with the
   following command:

 # pkg install wine

   Alternately compile the WINE sub-system from source with the following:

 # cd /usr/ports/emulator/wine
 # make install

  11.3.3. Concerns of 32- Versus 64-Bit in WINE Installations

   Like most software, Windows(R) applications made the upgrade from the
   older 32-bit architecture to 64 bits. And most recent software is written
   for 64-bit operating systems, although modern OSes can sometimes continue
   to run older 32-bit programs as well. FreeBSD is no different, having had
   support for 64-bit since the 5.x series.

   However, using old software no longer supported by default is a common use
   for emulators, and users commonly turn to WINE to play games and use other
   programs that do not run properly on modern hardware. Fortunately, FreeBSD
   can support all three scenarios:

     * On modern, 64-bit machine and want to run 64-bit Windows(R) software,
       simply install the ports mentioned in the above sections. The ports
       system will automatically install the 64-bit version.

     * Alternately, users might have an older 32-bit machine that they do not
       want to run with its original, now non-supported software. They can
       install the 32-bit (i386) version of FreeBSD, then install the ports
       in the above sections. Again, on a 32-bit machine the ports system
       will install the corresponding 32-bit version of WINE by default.

   However, given a 64-bit version of FreeBSD and need to run 32-bit
   Windows(R) applications, installing a different port is required to enable
   32-bit compatibility. To install the pre-compiled package, use the
   following:

 # pkg install i386-wine

   Or compile the port with the following:

 # cd /usr/ports/emulator/i386-wine
 # make install

11.4. Running a First WINE Program on FreeBSD

   Now that WINE is installed, the next step is to try it out by running a
   simple program. An easy way to do this is to download a self-contained
   application, i.e., one can simply unpack and run without any complex
   installation process.

   So-called "portable" versions of applications are good choices for this
   test, as are programs that run with only a single executable file.

  11.4.1. Running a Program from the Command Line

   There are two different methods to launch a Windows program from the
   terminal. The first, and most straightforward is to navigate to the
   directory containing the program's executable (.EXE) and issue the
   following:

 % wine program.exe

   For applications that take command-line arguments, add them after the
   executable as usual:

 % wine program2.exe -file file.txt

   Alternately, supply the full path to the executable to use it in a script,
   for example:

 % wine /home/user/bin/program.exe

  11.4.2. Running a Program from a GUI

   After installation graphical shells should be updated with new
   associations for Windows executable (.EXE) files. It will now be possible
   to browse the system using a file manager, and launch the Windows
   application in the same way as other files and programs (either a single-
   or double-click, depending on the desktop's settings).

   On most desktops, check to make sure this association is correct by
   right-clicking on the file, and looking for an entry in the context menu
   to open the file. One of the options (hopefully the default one) will be
   with the Wine Windows Program Loader, as shown in the below screenshot:

   In the event the program does not run as expected, try launching it from
   the command line and review any messages displayed in the terminal to
   troubleshoot.

   In the event WINE is not the default application for .EXE files after
   install, check the MIME associate for this extension in the current
   desktop environment, graphical shell, or file manager.

11.5. Configuring WINE Installation

   With an understanding of what WINE is and how it works at a high level,
   the next step to effectively using it on FreeBSD is becoming familiar with
   its configuration. The following sections will describe the key concept of
   the WINE prefix, and illustrate how it is used to control the behavior of
   applications run through WINE.

  11.5.1. WINE Prefixes

   A WINE prefix is a directory, usually located beneath the default location
   of $HOME/.wine though it can be located elsewhere. The prefix is a set of
   configurations and support files used by the wine to configure and run the
   Windows(R) environment a given application needs. By default, a brand new
   WINE installation will create the following structure when first launched
   by a user:

     * .update-timestamp: contains the last modified date of file
       /usr/share/wine/wine.inf. It is used by WINE to determine if a prefix
       is out of date, and automatically update it if needed.

     * dosdevices/: contains information on mappings of Windows(R) resources
       to resources on the host FreeBSD system. For example, after a new WINE
       installation, this should contain at least two entries which enable
       access to the FreeBSD filesystem using Windows(R)-style drive letters:

          * c:@: A link to drive_c described below.

          * z:@: A link to the root directory of the system.

     * drive_c/: emulates the main (i.e., C:) drive of a Windows(R) system.
       It contains a directory structure and associated files mirroring that
       of standard Windows(R) systems. A fresh WINE prefix will contain
       Windows(R) 10 directories such as Users and Windows that holds the OS
       itself. Furthermore, applications installed within a prefix will be
       located in either Program Files or Program Files (x86), depending on
       their architecture.

     * system.reg: This Registry file contains information on the Windows(R)
       installation, which in the case of WINE is the environment in drive_c.

     * user.reg: This Registry file contains the current user's personal
       configurations, made either by varous software or through the use of
       the Registry Editor.

     * userdef.reg: This Registry file is a default set of configurations for
       newly-created users.

  11.5.2. Creating and Using WINE Prefixes

   While WINE will create a default prefix in the user's $HOME/.wine/, it is
   possible to set up multiple prefixes. There are a few reasons to do this:

     * The most common reason is to emulate different versions of Windows(R),
       according to the compatibility needs of the software in question.

     * In addition, it is common to encounter software that does not work
       correctly in the default environment, and requires special
       configuration. it is useful to isolate these in their own, custom
       prefixes, so the changes do not impact other applications.

     * Similarly, copying the default or "main" prefix into a separate
       "testing" one in order to evaluate an application's compatibility can
       reduce the chance of corruption.

   Creating a prefix from the terminal requires the following command:

 % WINEPREFIX="/home/username/.wine-new" winecfg

   This will run the winecfg program, which can be used to configure wine
   prefixes (more on this in a later section). But by providing a directory
   path value for the WINEPREFIX environment variable, a new prefix is
   created at that location if one does not already exist.

   Supplying the same variable to the wine program will similarly cause the
   selected program to be run with the specified prefix:

 % WINEPREFIX="/home/username/.wine-new" wine program.exe

  11.5.3. Configuring WINE Prefixes with winecfg

   As described above WINE includes a tool called winecfg to configure
   prefixes from within a GUI. It contains a variety of functions, which are
   detailed in the sections below. When winecfg is run from within a prefix,
   or provided the location of a prefix within the WINEPREFIX variable, it
   enables the configuration of the selected prefix as described in the below
   sections.

   Selections made on the Applications tab will affect the scope of changes
   made in the Libraries and Graphics tabs, which will be limited to the
   application selected. See the section on Using Winecfg in the WINE Wiki
   for more details.

    11.5.3.1. Applications

   The Applications contains controls enabling the association of programs
   with a particular version of Windows(R). On first start-up the Application
   settings section will contain a single entry: Default Settings. This
   corresponds to all the default configurations of the prefix, which (as the
   disabled Remove application button implies) cannot be deleted.

   But additional applications can be added with the following process:

    1. Click the Add application button.

    2. Use the provided dialog to select the desired program's executable.

    3. Select the version of Windows(R) to be used with the selected program.

    11.5.3.2. Libraries

   WINE provides a set of open source library files as part of its
   distribution that provide the same functions as their Windows(R)
   counterparts. However, as noted earlier in this chapter, the WINE project
   is always trying to keep pace with new updates to these libraries. As a
   result, the versions that ship with WINE may be missing functionality that
   the latest Windows(R) programs are expecting.

   However, winecfg makes it possible specify overrides for the built-in
   libraries, particularly there is a version of Windows(R) available on the
   same machine as the host FreeBSD installation. For each library to be
   overridden, do the following:

    1. Open the New override for library drop-down and select the library to
       be replaced.

    2. Click the Add button.

    3. The new override will appear in the Existing overrides list, notice
       the native, builtin designation in parentheses.

    4. Click to select the library.

    5. Click the Edit button.

    6. Use the provided dialog to select a corresponding library to be used
       in place of the built-in one.

   Be sure to select a file that is truly the corresponding version of the
   built-in one, otherwise there may be unexpected behavior.

    11.5.3.3. Graphics

   The Graphics tab provides some options to make the windows of programs run
   via WINE operate smoothly with FreeBSD

     * Automatic mouse capture when windows are full-screen.

     * Allowing the FreeBSD window manager to decorate the windows, such as
       their title bars, for programs running via WINE.

     * Allowing the window manager to control windows for programs running
       via WINE, such as running resizing functions on them.

     * Create an emulated virtual desktop, within which all WINE programs
       will run. If this item is selected, the size of the virtual desktop
       can be specified using the Desktop size input boxes.

     * Setting the screen resolution for programs running via WINE.

    11.5.3.4. Desktop Integration

   This tab allows configuration of the following items:

     * The theme and related visual settings to be used for programs running
       via WINE.

     * Whether the WINE sub-system should manage MIME types (used to
       determine which application opens a particular file type) internally.

     * Mappings of directories in the host FreeBSD system to useful folders
       within the Windows(R) environment. To change an existing association,
       select the desired item and click Browse, then use the provided dialog
       to select a directory.

    11.5.3.5. Drives

   The Drives tab allows linking of directories in the host FreeBSD system to
   drive letters in the Windows(R) environment. The default values in this
   tab should look familiar, as they're displaying the contents of
   dosdevices/ in the current WINE prefix. Changes made via this dialog will
   reflect in dosdevices, and properly-formatted links created in that
   directory will display in this tab.

   To create a new entry, such as for a CD-ROM (mounted at /mnt/cdrom), take
   the following steps:

    1. Click the Add button.

    2. In the provided dialog, choose a free drive letter.

    3. Click OK.

    4. Fill in the Path input box by either typing the path to the resource,
       or click Browse and use the provided dialog to select it.

   By default WINE will autodetect the type of resource linked, but this can
   be manually overridden. See the section in the WINE Wiki for more detail
   on advanced options.

    11.5.3.6. Audio

   This tab contains some configurable options for routing sound from
   Windows(R) programs to the native FreeBSD sound system, including:

     * Driver selection

     * Default device selection

     * Sound test

    11.5.3.7. About

   The final tab contains information on the WINE project, including a link
   to the website. It also allows entry of (entirely optional) user
   information, although this is not sent anywhere as it is in other
   operating systems.

11.6. WINE Management GUIs

   While the base install of WINE comes with a GUI configuration tool in
   winecfg, it is main purpose is just that: strictly configuring an existing
   WINE prefix. There are, however, more advanced applications that will
   assist in the initial installation of applications as well as optimizing
   their WINE environments. The below sections include a selection of the
   most popular.

  11.6.1. Winetricks

   winetricks is a cross-platform, general purpose helper program for WINE.
   It is not developed by the WINE project proper, but rather maintained on
   Github by a group of contributors. It contains some automated "recipes"
   for getting common applications to work on WINE, both by optimizing the
   settings as well as acquiring some DLL libraries automatically.

    11.6.1.1. Installing winetricks

   To install winetricks on a FreeBSD using binary packages, use the
   following commands (note winetricks requires either the i386-wine or
   i386-wine-devel package, and is therefore not installed automatically with
   other dependencies):

 # pkg install i386-wine winetricks

   To compile it from source, issue the following in the terminal:

 # cd /usr/ports/emulators/i386-wine
 # make install
 # cd /usr/ports/emulators/winetricks
 # make install

   If a manual installation is required, refer to the Github account for
   instructions.

    11.6.1.2. Using winetricks

   Run winetricks with the following command:

 % winetricks

   Note: this should be in a 32-bit prefix to run winetricks. Launching
   winetricks displays a window with a number of choices, as follows:

   Selecting either Install an application, Install a benchmark, or Install a
   game shows a list with supported options, such as the one below for
   applications:

   Selecting one or more items and clicking OK will start their installation
   process(es). Initially, some messages that appear to be errors may show
   up, but they're actually informational alerts as winetricks configures the
   WINE environment to get around known issues for the application:

   Once these are circumvented, the actual installer for the application will
   be run:

   Once the installation completes, the new Windows application should be
   available from the desktop environment's standard menu (shown in the
   screenshot below for the LXQT desktop environment):

   In order to remove the application, run winetricks again, and select Run
   an uninstaller.

   A Windows(R)-style dialog will appear with a list of installed programs
   and components. Select the application to be removed, then click the
   Modify/Remove button.

   This will run the applications built-in installer, which should also have
   the option to uninstall.

  11.6.2. Homura

   Homura is an application similar to winetricks, although it was inspired
   by the Lutris gaming system for Linux. But while it is focused on games,
   there are also non-gaming applications available for install through
   Homura.

    11.6.2.1. Installing Homura

   To install Homura's binary package, issue the following command:

 # pkg install homura

   Homura is available in the FreeBSD Ports system. However, than the
   emulators section of Ports or binary packages, look for it in the games
   section.

 # cd /usr/ports/games/homura
 # make install

    11.6.2.2. Using Homura

   Homura's usage is quite similar to that of winetricks. When using it for
   the first time, launch it from the command line (or a desktop environment
   runner applet) with:

 % Homura

   This should result in a friendly welcome message. Click OK to continue.

   The program will also offer to place a link in the application menu of
   compatible environments:

   Depending on the setup of the FreeBSD machine, Homura may display a
   message urging the install of native graphics drivers.

   The application's window should then appear, which amounts to a "main
   menu" with all its options. Many of the items are the same as winetricks,
   although Homura offers some additional, helpful options such as opening
   its data folder (Open Homura Folder) or running a specified program (Run a
   executable in prefix).

   To select one of Homura's supported applications to install, select
   Installation, and click OK. This will display a list of applications
   Homura can install automatically. Select one, and click OK to start the
   process.

   As a first step Homura will download the selected program. A notification
   may appear in supported desktop environments.

   The program will also create a new prefix for the application. A standard
   WINE dialog with this message will display.

   Next, Homura will install any prerequisites for the selected program. This
   may involve downloading and extracting a fair number of files, the details
   of which will show in dialogs.

   Downloaded packages are automatically opened and run as required.

   The installation may end with a simple desktop notification or message in
   the terminal, depending on how Homura was launched. But in either case
   Homura should return to the main screen. To confirm the installation was
   successful, select Launcher, and click OK.

   This will display a list of installed applications.

   To run the new program, select it from the list, and click OK. To
   uninstall the application, select Uninstallation from the main screen,
   which will display a similar list. Select the program to be removed, and
   click OK.

  11.6.3. Running Multiple Management GUIs

   it is worth noting that the above solutions are not mutually exclusive. it
   is perfectly acceptable, even advantageous, to have both installed at the
   same time, as they support a different set of programs.

   However, it is wise to ensure that they do not access any of the same WINE
   prefixes. Each of these solutions applies workarounds and makes changes to
   the registries based on known workarounds to existing WINE issues in order
   to make a given application run smoothly. Allowing both winetricks and
   Homura to access the same prefix could lead to some of these being
   overwritten, with the result being some or all applications do not work as
   expected.

11.7. WINE in Multi-User FreeBSD Installations

  11.7.1. Issues with Using a Common WINE Prefix

   Like most UNIX(R)-like operating systems, FreeBSD is designed for multiple
   users to be logged in and working at the same time. On the other hand,
   Windows(R) is multi-user in the sense that there can be multiple user
   accounts set up on one system. But the expectation is that only one will
   be using the physical machine (a desktop or laptop PC) at any given
   moment.

   More recent consumer versions of Windows(R) have taken some steps to
   improve the OS in multi-user scenarios. But it is still largely structured
   around a single-user experience. Furthermore, the measures the WINE
   project has taken to create acompatible environment means, unlike FreeBSD
   applications (including WINE itself), it will resemble this single-user
   environment.

   So it follows that each user will have to maintain their own set of
   configurations, which is potentially good. Yet it is advantageous to
   install applications, particularly large ones like office suites or games,
   only once. Two examples of reasons to do this are maintenance (software
   updates need only be applied once) and efficiency in storage (no
   duplicated files).

   There are two strategies to minimze the impact of multiple WINE users in
   the system.

  11.7.2. Installing Applications to a Common Drive

   As shown in the section on WINE Configuration, WINE provides the ability
   to attach additional drives to a given prefix. In this way, applications
   can be installed to a common location, while each user will still have an
   prefix where individual settings may be kept (depending on the program).
   This is a good setup if there are relatively few applications to be shared
   between users, and they are programs that require few custom tweaks
   changes to the prefix in order to function.

   The steps to make install applications in this way are as follows:

    1. First, set up a shared location on the system where the files will be
       stored, such as /mnt/windows-drive_d/. Creating new directories is
       described in man page for the mkdir command.

    2. Next, set permissions for this new directory to allow only desired
       users to access it. One approach to this is to create a new group such
       as "windows," add the desired users to that group (see the sub-section
       on groups in the Handbook's Users and Basic Account Management
       section), and set to the permissions on the directory to 770 (the
       section on Permissions in the FreeBSD Basics chapter of the Handbook
       illustrates this process).

    3. Finally, add the location as a drive to the user's prefix using the
       winecfg as described in the above section on WINE Configuration in
       this chapter.

   Once complete, applications can be installed to this location, and
   subsequently run using the assigned drive letter (or the standard
   UNIX(R)-style directory path). However, as noted above, only one user
   should be running these applications (which may be accessing files within
   their installation directory) at the same time. Some applications may also
   exhibit unexpected behavior when run by a user who is not the owner,
   despite being a member of the group that should have full
   "read/write/execute" permissions for the entire directory.

  11.7.3. Using a Common Installation of WINE

   If, on the other hand, there are many applications to be shared, or they
   require specific tuning in order to work correctly, a different approach
   may be required. In this method, a completely separate user is created
   specifically for the purposes of storing the WINE prefix and all its
   installed applications. Individual users are then granted permission to
   run programs as this user using the su command. The result is that these
   users can launch a WINE application as they normally would, only it will
   act as though launched by the newly-created user, and therefore use the
   centrally-maintained prefix containing both settings and programs. To
   accomplish this, take the following steps.

   Create a new user with the following command (as root), which will step
   through the required details:

 # adduser

   Enter the username (e.g., windows) and Full name ("Microsoft Windows").
   Then accept the defaults for the remainder of the questions. Next, install
   the sudo utlity using binary packages with the following:

 # pkg install sudo

   Once installed, edit /etc/sudoers as follows:

 # User alias specification

 # define which users can run the wine/windows programs
 User_Alias WINDOWS_USERS = user1,user2

 # define which users can administrate (become root)
 User_Alias ADMIN = user1

 # Cmnd alias specification

 # define which commands the WINDOWS_USERS may run
 Cmnd_Alias WINDOWS = /usr/bin/wine,/usr/bin/winecfg

 # Defaults
 Defaults:WINDOWS_USERS env_reset
 Defaults:WINDOWS_USERS env_keep += DISPLAY
 Defaults:WINDOWS_USERS env_keep += XAUTHORITY
 Defaults    !lecture,tty_tickets,!fqdn

 # User privilege specification
 root    ALL=(ALL) ALL

 # Members of the admin user_alias, defined above, may gain root privileges
 ADMIN ALL=(ALL) ALL

 # The WINDOWS_USERS may run WINDOWS programs as user windows without a password
 WINDOWS_USERS ALL = (windows) NOPASSWD: WINDOWS

   The result of these changes is the users named in the User_Alias section
   are permitted to run the programs listed in the CmndAlias section using
   the resources listed in the Defaults section (the current display) as if
   they were the user listed in the final line of the file. In other words,
   users designates as WINDOWS_USERS can run the wine and winecfg
   applications as user windows. As a bonus, the configuration here means
   they will not be required to enter the password for the windows user.

   Next provide access to the display back to the windows user, as whom the
   WINE programs will be running:

 % xhost +local:windows

   This should be added to the list of commands run either at login or when
   the default graphical environment starts. Once all the above are complete,
   a user configured as one of the WINDOW_USERS in sudoers can run programs
   using the shared prefix with the following command:

   it is worth noting that multiple users accessing this shared environment
   at the same time is still risky. However, consider also that the shared
   environment can itself contain multiple prefixes. In this way an
   administrator can create a tested and verified set of programs, each with
   its own prefix. At the same time, one user can play a game while another
   works with office programs without the need for redundant software
   installations.

11.8. WINE on FreeBSD FAQ

   The following section describes some frequently asked questions,
   tips/tricks, or common issues in running WINE on FreeBSD, along with their
   respective answers.

  11.8.1. Basic Installation and Usage

    11.8.1.1. How to Install 32-bit and 64-bit WINE on the Same System?

   As described earlier in this section, the wine and i386-wine packages
   conflict with one another, and therefore cannot be installed on the same
   system in the normal way. However, multiple installs can be achieved using
   mechanisms like chroots/jails, or by building WINE from source (note this
   does not mean building the port).

    11.8.1.2. Can DOS Programs Be Run on WINE?

   They can, as "Console User Interface" applications as mentioned eariler in
   this section. However, there is an arguably better method for running DOS
   software: DOSBox. On the other hand, there's little reason not to at least
   try it. Simply create a new prefix, install the software, and if it does
   not work delete the prefix.

    11.8.1.3. Should the "wine-devel" Package/Port be Installed to Use the
    Development Version of WINE Instead of Stable?

   Yes, installing this version will install the "development" version of
   WINE. As with the 32- and 64-bit versions, they cannot be installed
   together with the stable versions unless additional measures are taken.

   Note that WINE also has a "Staging" version, which contains the most
   recent updates. This was at one time available as a FreeBSD port; however,
   it has since been removed. It can be compiled directly from source
   however.

  11.8.2. Install Optimization

    11.8.2.1. How Should Windows(R) Hardware (e.g., Graphics) Drivers be
    Handled?

   Operating system drivers transfer commands between applications and
   hardware. WINE emulates a Windows(R) environment, including the drivers,
   which in turn use FreeBSD's native drivers for this transfer. it is not
   advisable to install Windows(R) drivers, as the WINE system is designed to
   use the host systems drivers. If, for example, a graphics card that
   benefits from dedicated drivers, install them using the standard FreeBSD
   methods, not Windows(R) installers.

    11.8.2.2. Is There a way to Make Windows(R) Fonts Look Better?

   A user on the FreeBSD forums suggests this configuration to fix
   out-of-the-box look of WINE fonts, which can be slightly pixelated.

   According to a post in the FreeBSD Forums, adding the following to
   .config/fontconfig/fonts.conf will add anti-aliasing and make text more
   readable.

 <?xml version="1.0"?>
 <!DOCTYPE fontconfig SYSTEM "fonts.dtd>"

 <fontconfig>

   <!-- antialias all fonts -->
   <match target="font">
     <edit name="antialias" mode="assign"><bool>true</bool></edit>>
     <edit name="hinting" mode="assign"><bool>true</bool></edit>>
     <edit name="hintstyle" mode="assign"><const>hintslight</const></edit>>
     <edit name="rgba" mode="assign"><const>rgb</const></edit>>
   </match>
 </fontconfig>

    11.8.2.3. Does Having Windows(R) Installed Elsewhere on a System Help WINE
    Operate?

   It may, depending on the application being run. As mentioned in the
   section describing winecfg, some built-in WINE DLLs and other libraries
   can be overridden by providing a path to an alternate version. Provided
   the Windows(R) partition or drive is mounted to the FreeBSD system and
   accessible to the user, configuring some of these overrides will use
   native Windows(R) libraries and may decrease the chance of unexpected
   behavior.

  11.8.3. Application-Specific

    11.8.3.1. Where is the Best Place to see if Application X Works on WINE?

   The first stop in determining compatibiliy should be the WINE AppDB. This
   is a compilation of reports of programs working (or not) on all supported
   platforms, although (as previously mentioned), solutions for one platform
   are often applicable to others.

    11.8.3.2. Is There Anything That Will Help Games Run Better?

   Perhaps. Many Windows(R) games rely on DirectX, a proprietary Microsoft
   graphics layer. However there are projects in the open source community
   attempting to implement support for this technology.

   The dxvk project, which is an attempt to implement DirectX using the
   FreeBSD-compatible Vulkan graphics sub-system, is one such. Although its
   primary target is WINE on Linux, some FreeBSD users report compiling and
   using dxvk.

   In addition, work is under way on a wine-proton port. This will bring the
   work of Valve, developer of the Steam gaming platform, to FreeBSD. Proton
   is a distribution of WINE designed to allow many Windows(R) games to run
   on other operating systems with minimal setup.

    11.8.3.3. Is There Anywhere FreeBSD WINE Users Gather to Exchange Tips and
    Tricks?

   There are plenty of places FreeBSD users discuss issues related to WINE
   that can be searched for solutions:

     * The FreeBSD forums, particularly the Installation and Maintenance of
       Ports or Packages or Emulation and virtualization forums.

     * FreeBSD IRC channels including #freebsd (for general support),
       #freebsd-games, and others.

     * The BSD World Discord server's channels including bsd-desktop,
       bsd-gaming, bsd-wine, and others.

  11.8.4. Other OS Resources

   There are a number of resources focused on other operating systems that
   may be useful for FreeBSD users:

     * The WINE Wiki has a wealth of information on using WINE, much of which
       is applicable across many of WINE's supported operating systems.

     * Similarly, the documentation available from other OS projects can also
       be of good value. The WINE page on the Arch Linux Wiki is a
       particularly good example, although some of the "Third-party
       applications" (i.e., "companion applications") are obviously not
       available on FreeBSD.

     * Finally, Codeweavers (a developer of a commercial version of WINE) is
       an active upstream contributor. Oftentimes answers to questions in
       their support forum can be of aid in troubleshooting problems with the
       open source version of WINE.

                        Part III. System Administration

   The remaining chapters cover all aspects of FreeBSD system administration.
   Each chapter starts by describing what will be learned as a result of
   reading the chapter, and also details what the reader is expected to know
   before tackling the material.

   These chapters are designed to be read as the information is needed. They
   do not need to be read in any particular order, nor must all of them be
   read before beginning to use FreeBSD.

   Table of Contents

   12. Configuration and Tuning

                12.1. Synopsis

                12.2. Starting Services

                12.3. Configuring cron(8)

                12.4. Managing Services in FreeBSD

                12.5. Setting Up Network Interface Cards

                12.6. Virtual Hosts

                12.7. Configuring System Logging

                12.8. Configuration Files

                12.9. Tuning with sysctl(8)

                12.10. Tuning Disks

                12.11. Tuning Kernel Limits

                12.12. Adding Swap Space

                12.13. Power and Resource Management

   13. The FreeBSD Booting Process

                13.1. Synopsis

                13.2. FreeBSD Boot Process

                13.3. Configuring Boot Time Splash Screens

                13.4. Device Hints

                13.5. Shutdown Sequence

   14. Security

                14.1. Synopsis

                14.2. Introduction

                14.3. One-time Passwords

                14.4. TCP Wrapper

                14.5. Kerberos

                14.6. OpenSSL

                14.7. VPN over IPsec

                14.8. OpenSSH

                14.9. Access Control Lists

                14.10. Monitoring Third Party Security Issues

                14.11. FreeBSD Security Advisories

                14.12. Process Accounting

                14.13. Resource Limits

                14.14. Shared Administration with Sudo

   15. Jails

                15.1. Synopsis

                15.2. Terms Related to Jails

                15.3. Creating and Controlling Jails

                15.4. Fine Tuning and Administration

                15.5. Updating Multiple Jails

                15.6. Managing Jails with ezjail

   16. Mandatory Access Control

                16.1. Synopsis

                16.2. Key Terms

                16.3. Understanding MAC Labels

                16.4. Planning the Security Configuration

                16.5. Available MAC Policies

                16.6. User Lock Down

                16.7. Nagios in a MAC Jail

                16.8. Troubleshooting the MAC Framework

   17. Security Event Auditing

                17.1. Synopsis

                17.2. Key Terms

                17.3. Audit Configuration

                17.4. Working with Audit Trails

   18. Storage

                18.1. Synopsis

                18.2. Adding Disks

                18.3. Resizing and Growing Disks

                18.4. USB Storage Devices

                18.5. Creating and Using CD Media

                18.6. Creating and Using DVD Media

                18.7. Creating and Using Floppy Disks

                18.8. Backup Basics

                18.9. Memory Disks

                18.10. File System Snapshots

                18.11. Disk Quotas

                18.12. Encrypting Disk Partitions

                18.13. Encrypting Swap

                18.14. Highly Available Storage (HAST)

   19. GEOM: Modular Disk Transformation Framework

                19.1. Synopsis

                19.2. RAID0 - Striping

                19.3. RAID1 - Mirroring

                19.4. RAID3 - Byte-level Striping with Dedicated Parity

                19.5. Software RAID Devices

                19.6. GEOM Gate Network

                19.7. Labeling Disk Devices

                19.8. UFS Journaling Through GEOM

   20. The Z File System (ZFS)

                20.1. What Makes ZFS Different

                20.2. Quick Start Guide

                20.3. zpool Administration

                20.4. zfs Administration

                20.5. Delegated Administration

                20.6. Advanced Topics

                20.7. Additional Resources

                20.8. ZFS Features and Terminology

   21. Other File Systems

                21.1. Synopsis

                21.2. Linux(R) File Systems

   22. Virtualization

                22.1. Synopsis

                22.2. FreeBSD as a Guest on Parallels for Mac OS(R) X

                22.3. FreeBSD as a Guest on Virtual PC for Windows(R)

                22.4. FreeBSD as a Guest on VMware Fusion for Mac OS(R)

                22.5. FreeBSD as a Guest on VirtualBox(TM)

                22.6. FreeBSD as a Host with VirtualBox(TM)

                22.7. FreeBSD as a Host with bhyve

                22.8. FreeBSD as a Xen(TM)-Host

   23. Localization - i18n/L10n Usage and Setup

                23.1. Synopsis

                23.2. Using Localization

                23.3. Finding i18n Applications

                23.4. Locale Configuration for Specific Languages

   24. Updating and Upgrading FreeBSD

                24.1. Synopsis

                24.2. FreeBSD Update

                24.3. Updating the Documentation Set

                24.4. Tracking a Development Branch

                24.5. Updating FreeBSD from Source

                24.6. Tracking for Multiple Machines

   25. DTrace

                25.1. Synopsis

                25.2. Implementation Differences

                25.3. Enabling DTrace Support

                25.4. Using DTrace

   26. USB Device Mode / USB OTG

                26.1. Synopsis

                26.2. USB Virtual Serial Ports

                26.3. USB Device Mode Network Interfaces

                26.4. USB Virtual Storage Device

Chapter 12. Configuration and Tuning

   Written by Chern Lee.
   Based on a tutorial written by Mike Smith.
   Also based on tuning(7) written by Matt Dillon.
   Table of Contents

   12.1. Synopsis

   12.2. Starting Services

   12.3. Configuring cron(8)

   12.4. Managing Services in FreeBSD

   12.5. Setting Up Network Interface Cards

   12.6. Virtual Hosts

   12.7. Configuring System Logging

   12.8. Configuration Files

   12.9. Tuning with sysctl(8)

   12.10. Tuning Disks

   12.11. Tuning Kernel Limits

   12.12. Adding Swap Space

   12.13. Power and Resource Management

12.1. Synopsis

   One of the important aspects of FreeBSD is proper system configuration.
   This chapter explains much of the FreeBSD configuration process, including
   some of the parameters which can be set to tune a FreeBSD system.

   After reading this chapter, you will know:

     * The basics of rc.conf configuration and /usr/local/etc/rc.d startup
       scripts.

     * How to configure and test a network card.

     * How to configure virtual hosts on network devices.

     * How to use the various configuration files in /etc.

     * How to tune FreeBSD using sysctl(8) variables.

     * How to tune disk performance and modify kernel limitations.

   Before reading this chapter, you should:

     * Understand UNIX(R) and FreeBSD basics (Chapter 3, FreeBSD Basics).

     * Be familiar with the basics of kernel configuration and compilation
       (Chapter 8, Configuring the FreeBSD Kernel).

12.2. Starting Services

   Contributed by Tom Rhodes.

   Many users install third party software on FreeBSD from the Ports
   Collection and require the installed services to be started upon system
   initialization. Services, such as mail/postfix or www/apache22 are just
   two of the many software packages which may be started during system
   initialization. This section explains the procedures available for
   starting third party software.

   In FreeBSD, most included services, such as cron(8), are started through
   the system startup scripts.

  12.2.1. Extended Application Configuration

   Now that FreeBSD includes rc.d, configuration of application startup is
   easier and provides more features. Using the key words discussed in
   Section 12.4, "Managing Services in FreeBSD", applications can be set to
   start after certain other services and extra flags can be passed through
   /etc/rc.conf in place of hard coded flags in the startup script. A basic
   script may look similar to the following:

 #!/bin/sh
 #
 # PROVIDE: utility
 # REQUIRE: DAEMON
 # KEYWORD: shutdown

 . /etc/rc.subr

 name=utility
 rcvar=utility_enable

 command="/usr/local/sbin/utility"

 load_rc_config $name

 #
 # DO NOT CHANGE THESE DEFAULT VALUES HERE
 # SET THEM IN THE /etc/rc.conf FILE
 #
 utility_enable=${utility_enable-"NO"}
 pidfile=${utility_pidfile-"/var/run/utility.pid"}

 run_rc_command "$1"

   This script will ensure that the provided utility will be started after
   the DAEMON pseudo-service. It also provides a method for setting and
   tracking the process ID (PID).

   This application could then have the following line placed in
   /etc/rc.conf:

 utility_enable="YES"

   This method allows for easier manipulation of command line arguments,
   inclusion of the default functions provided in /etc/rc.subr, compatibility
   with rcorder(8), and provides for easier configuration via rc.conf.

  12.2.2. Using Services to Start Services

   Other services can be started using inetd(8). Working with inetd(8) and
   its configuration is described in depth in Section 30.2, "The inetd
   Super-Server".

   In some cases, it may make more sense to use cron(8) to start system
   services. This approach has a number of advantages as cron(8) runs these
   processes as the owner of the crontab(5). This allows regular users to
   start and maintain their own applications.

   The @reboot feature of cron(8), may be used in place of the time
   specification. This causes the job to run when cron(8) is started,
   normally during system initialization.

12.3. Configuring cron(8)

   Contributed by Tom Rhodes.

   One of the most useful utilities in FreeBSD is cron. This utility runs in
   the background and regularly checks /etc/crontab for tasks to execute and
   searches /var/cron/tabs for custom crontab files. These files are used to
   schedule tasks which cron runs at the specified times. Each entry in a
   crontab defines a task to run and is known as a cron job.

   Two different types of configuration files are used: the system crontab,
   which should not be modified, and user crontabs, which can be created and
   edited as needed. The format used by these files is documented in
   crontab(5). The format of the system crontab, /etc/crontab includes a who
   column which does not exist in user crontabs. In the system crontab, cron
   runs the command as the user specified in this column. In a user crontab,
   all commands run as the user who created the crontab.

   User crontabs allow individual users to schedule their own tasks. The root
   user can also have a user crontab which can be used to schedule tasks that
   do not exist in the system crontab.

   Here is a sample entry from the system crontab, /etc/crontab:

 # /etc/crontab - root's crontab for FreeBSD
 #
 # $FreeBSD$
 # 1
 SHELL=/bin/sh
 PATH=/etc:/bin:/sbin:/usr/bin:/usr/sbin 2
 #
 #minute hour    mday    month   wday    who     command 3
 #
 */5     *       *       *       *       root    /usr/libexec/atrun 4

   1 Lines that begin with the # character are comments. A comment can be     
     placed in the file as a reminder of what and why a desired action is     
     performed. Comments cannot be on the same line as a command or else they 
     will be interpreted as part of the command; they must be on a new line.  
     Blank lines are ignored.                                                 
   2 The equals (=) character is used to define any environment settings. In  
     this example, it is used to define the SHELL and PATH. If the SHELL is   
     omitted, cron will use the default Bourne shell. If the PATH is omitted, 
     the full path must be given to the command or script to run.             
   3 This line defines the seven fields used in a system crontab: minute,     
     hour, mday, month, wday, who, and command. The minute field is the time  
     in minutes when the specified command will be run, the hour is the hour  
     when the specified command will be run, the mday is the day of the       
     month, month is the month, and wday is the day of the week. These fields 
     must be numeric values, representing the twenty-four hour clock, or a *, 
     representing all values for that field. The who field only exists in the 
     system crontab and specifies which user the command should be run as.    
     The last field is the command to be executed.                            
   4 This entry defines the values for this cron job. The */5, followed by    
     several more * characters, specifies that /usr/libexec/atrun is invoked  
     by root every five minutes of every hour, of every day and day of the    
     week, of every month.                                                    
                                                                              
     Commands can include any number of switches. However, commands which     
     extend to multiple lines need to be broken with the backslash "\"        
     continuation character.                                                  

  12.3.1. Creating a User Crontab

   To create a user crontab, invoke crontab in editor mode:

 % crontab -e

   This will open the user's crontab using the default text editor. The first
   time a user runs this command, it will open an empty file. Once a user
   creates a crontab, this command will open that file for editing.

   It is useful to add these lines to the top of the crontab file in order to
   set the environment variables and to remember the meanings of the fields
   in the crontab:

 SHELL=/bin/sh
 PATH=/etc:/bin:/sbin:/usr/bin:/usr/sbin
 # Order of crontab fields
 # minute        hour    mday    month   wday    command

   Then add a line for each command or script to run, specifying the time to
   run the command. This example runs the specified custom Bourne shell
   script every day at two in the afternoon. Since the path to the script is
   not specified in PATH, the full path to the script is given:

 0       14      *       *       *       /usr/home/dru/bin/mycustomscript.sh

  Tip:

   Before using a custom script, make sure it is executable and test it with
   the limited set of environment variables set by cron. To replicate the
   environment that would be used to run the above cron entry, use:

 env -i SHELL=/bin/sh PATH=/etc:/bin:/sbin:/usr/bin:/usr/sbin HOME=/home/dru LOGNAME=dru /usr/home/dru/bin/mycustomscript.sh

   The environment set by cron is discussed in crontab(5). Checking that
   scripts operate correctly in a cron environment is especially important if
   they include any commands that delete files using wildcards.

   When finished editing the crontab, save the file. It will automatically be
   installed and cron will read the crontab and run its cron jobs at their
   specified times. To list the cron jobs in a crontab, use this command:

 % crontab -l
 0       14      *       *       *       /usr/home/dru/bin/mycustomscript.sh

   To remove all of the cron jobs in a user crontab:

 % crontab -r
 remove crontab for dru? y

12.4. Managing Services in FreeBSD

   Contributed by Tom Rhodes.

   FreeBSD uses the rc(8) system of startup scripts during system
   initialization and for managing services. The scripts listed in /etc/rc.d
   provide basic services which can be controlled with the start, stop, and
   restart options to service(8). For instance, sshd(8) can be restarted with
   the following command:

 # service sshd restart

   This procedure can be used to start services on a running system. Services
   will be started automatically at boot time as specified in rc.conf(5). For
   example, to enable natd(8) at system startup, add the following line to
   /etc/rc.conf:

 natd_enable="YES"

   If a natd_enable="NO" line is already present, change the NO to YES. The
   rc(8) scripts will automatically load any dependent services during the
   next boot, as described below.

   Since the rc(8) system is primarily intended to start and stop services at
   system startup and shutdown time, the start, stop and restart options will
   only perform their action if the appropriate /etc/rc.conf variable is set.
   For instance, sshd restart will only work if sshd_enable is set to YES in
   /etc/rc.conf. To start, stop or restart a service regardless of the
   settings in /etc/rc.conf, these commands should be prefixed with "one".
   For instance, to restart sshd(8) regardless of the current /etc/rc.conf
   setting, execute the following command:

 # service sshd onerestart

   To check if a service is enabled in /etc/rc.conf, run the appropriate
   rc(8) script with rcvar. This example checks to see if sshd(8) is enabled
   in /etc/rc.conf:

 # service sshd rcvar
 # sshd
 #
 sshd_enable="YES"
 #   (default: "")

  Note:

   The # sshd line is output from the above command, not a root console.

   To determine whether or not a service is running, use status. For
   instance, to verify that sshd(8) is running:

 # service sshd status
 sshd is running as pid 433.

   In some cases, it is also possible to reload a service. This attempts to
   send a signal to an individual service, forcing the service to reload its
   configuration files. In most cases, this means sending the service a
   SIGHUP signal. Support for this feature is not included for every service.

   The rc(8) system is used for network services and it also contributes to
   most of the system initialization. For instance, when the /etc/rc.d/bgfsck
   script is executed, it prints out the following message:

 Starting background file system checks in 60 seconds.

   This script is used for background file system checks, which occur only
   during system initialization.

   Many system services depend on other services to function properly. For
   example, yp(8) and other RPC-based services may fail to start until after
   the rpcbind(8) service has started. To resolve this issue, information
   about dependencies and other meta-data is included in the comments at the
   top of each startup script. The rcorder(8) program is used to parse these
   comments during system initialization to determine the order in which
   system services should be invoked to satisfy the dependencies.

   The following key word must be included in all startup scripts as it is
   required by rc.subr(8) to "enable" the startup script:

     * PROVIDE: Specifies the services this file provides.

   The following key words may be included at the top of each startup script.
   They are not strictly necessary, but are useful as hints to rcorder(8):

     * REQUIRE: Lists services which are required for this service. The
       script containing this key word will run after the specified services.

     * BEFORE: Lists services which depend on this service. The script
       containing this key word will run before the specified services.

   By carefully setting these keywords for each startup script, an
   administrator has a fine-grained level of control of the startup order of
   the scripts, without the need for "runlevels" used by some UNIX(R)
   operating systems.

   Additional information can be found in rc(8) and rc.subr(8). Refer to this
   article for instructions on how to create custom rc(8) scripts.

  12.4.1. Managing System-Specific Configuration

   The principal location for system configuration information is
   /etc/rc.conf. This file contains a wide range of configuration information
   and it is read at system startup to configure the system. It provides the
   configuration information for the rc* files.

   The entries in /etc/rc.conf override the default settings in
   /etc/defaults/rc.conf. The file containing the default settings should not
   be edited. Instead, all system-specific changes should be made to
   /etc/rc.conf.

   A number of strategies may be applied in clustered applications to
   separate site-wide configuration from system-specific configuration in
   order to reduce administration overhead. The recommended approach is to
   place system-specific configuration into /etc/rc.conf.local. For example,
   these entries in /etc/rc.conf apply to all systems:

 sshd_enable="YES"
 keyrate="fast"
 defaultrouter="10.1.1.254"

   Whereas these entries in /etc/rc.conf.local apply to this system only:

 hostname="node1.example.org"
 ifconfig_fxp0="inet 10.1.1.1/8"

   Distribute /etc/rc.conf to every system using an application such as rsync
   or puppet, while /etc/rc.conf.local remains unique.

   Upgrading the system will not overwrite /etc/rc.conf, so system
   configuration information will not be lost.

  Tip:

   Both /etc/rc.conf and /etc/rc.conf.local are parsed by sh(1). This allows
   system operators to create complex configuration scenarios. Refer to
   rc.conf(5) for further information on this topic.

12.5. Setting Up Network Interface Cards

   Contributed by Marc Fonvieille.

   Adding and configuring a network interface card (NIC) is a common task for
   any FreeBSD administrator.

  12.5.1. Locating the Correct Driver

   First, determine the model of the NIC and the chip it uses. FreeBSD
   supports a wide variety of NICs. Check the Hardware Compatibility List for
   the FreeBSD release to see if the NIC is supported.

   If the NIC is supported, determine the name of the FreeBSD driver for the
   NIC. Refer to /usr/src/sys/conf/NOTES and /usr/src/sys/arch/conf/NOTES for
   the list of NIC drivers with some information about the supported
   chipsets. When in doubt, read the manual page of the driver as it will
   provide more information about the supported hardware and any known
   limitations of the driver.

   The drivers for common NICs are already present in the GENERIC kernel,
   meaning the NIC should be probed during boot. The system's boot messages
   can be viewed by typing more /var/run/dmesg.boot and using the spacebar to
   scroll through the text. In this example, two Ethernet NICs using the
   dc(4) driver are present on the system:

 dc0: <82c169 PNIC 10/100BaseTX> port 0xa000-0xa0ff mem 0xd3800000-0xd38
 000ff irq 15 at device 11.0 on pci0
 miibus0: <MII bus> on dc0
 bmtphy0: <BCM5201 10/100baseTX PHY> PHY 1 on miibus0
 bmtphy0:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
 dc0: Ethernet address: 00:a0:cc:da:da:da
 dc0: [ITHREAD]
 dc1: <82c169 PNIC 10/100BaseTX> port 0x9800-0x98ff mem 0xd3000000-0xd30
 000ff irq 11 at device 12.0 on pci0
 miibus1: <MII bus> on dc1
 bmtphy1: <BCM5201 10/100baseTX PHY> PHY 1 on miibus1
 bmtphy1:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
 dc1: Ethernet address: 00:a0:cc:da:da:db
 dc1: [ITHREAD]

   If the driver for the NIC is not present in GENERIC, but a driver is
   available, the driver will need to be loaded before the NIC can be
   configured and used. This may be accomplished in one of two ways:

     * The easiest way is to load a kernel module for the NIC using
       kldload(8). To also automatically load the driver at boot time, add
       the appropriate line to /boot/loader.conf. Not all NIC drivers are
       available as modules.

     * Alternatively, statically compile support for the NIC into a custom
       kernel. Refer to /usr/src/sys/conf/NOTES, /usr/src/sys/arch/conf/NOTES
       and the manual page of the driver to determine which line to add to
       the custom kernel configuration file. For more information about
       recompiling the kernel, refer to Chapter 8, Configuring the FreeBSD
       Kernel. If the NIC was detected at boot, the kernel does not need to
       be recompiled.

    12.5.1.1. Using Windows(R) NDIS Drivers

   Unfortunately, there are still many vendors that do not provide schematics
   for their drivers to the open source community because they regard such
   information as trade secrets. Consequently, the developers of FreeBSD and
   other operating systems are left with two choices: develop the drivers by
   a long and pain-staking process of reverse engineering or using the
   existing driver binaries available for Microsoft(R) Windows(R) platforms.

   FreeBSD provides "native" support for the Network Driver Interface
   Specification (NDIS). It includes ndisgen(8) which can be used to convert
   a Windows(R) XP driver into a format that can be used on FreeBSD. As the
   ndis(4) driver uses a Windows(R) XP binary, it only runs on i386(TM) and
   amd64 systems. PCI, CardBus, PCMCIA, and USB devices are supported.

   To use ndisgen(8), three things are needed:

    1. FreeBSD kernel sources.

    2. A Windows(R) XP driver binary with a .SYS extension.

    3. A Windows(R) XP driver configuration file with a .INF extension.

   Download the .SYS and .INF files for the specific NIC. Generally, these
   can be found on the driver CD or at the vendor's website. The following
   examples use W32DRIVER.SYS and W32DRIVER.INF.

   The driver bit width must match the version of FreeBSD. For FreeBSD/i386,
   use a Windows(R) 32-bit driver. For FreeBSD/amd64, a Windows(R) 64-bit
   driver is needed.

   The next step is to compile the driver binary into a loadable kernel
   module. As root, use ndisgen(8):

 # ndisgen /path/to/W32DRIVER.INF /path/to/W32DRIVER.SYS

   This command is interactive and prompts for any extra information it
   requires. A new kernel module will be generated in the current directory.
   Use kldload(8) to load the new module:

 # kldload ./W32DRIVER_SYS.ko

   In addition to the generated kernel module, the ndis.ko and if_ndis.ko
   modules must be loaded. This should happen automatically when any module
   that depends on ndis(4) is loaded. If not, load them manually, using the
   following commands:

 # kldload ndis
 # kldload if_ndis

   The first command loads the ndis(4) miniport driver wrapper and the second
   loads the generated NIC driver.

   Check dmesg(8) to see if there were any load errors. If all went well, the
   output should be similar to the following:

 ndis0: <Wireless-G PCI Adapter> mem 0xf4100000-0xf4101fff irq 3 at device 8.0 on pci1
 ndis0: NDIS API version: 5.0
 ndis0: Ethernet address: 0a:b1:2c:d3:4e:f5
 ndis0: 11b rates: 1Mbps 2Mbps 5.5Mbps 11Mbps
 ndis0: 11g rates: 6Mbps 9Mbps 12Mbps 18Mbps 36Mbps 48Mbps 54Mbps

   From here, ndis0 can be configured like any other NIC.

   To configure the system to load the ndis(4) modules at boot time, copy the
   generated module, W32DRIVER_SYS.ko, to /boot/modules. Then, add the
   following line to /boot/loader.conf:

 W32DRIVER_SYS_load="YES"

  12.5.2. Configuring the Network Card

   Once the right driver is loaded for the NIC, the card needs to be
   configured. It may have been configured at installation time by
   bsdinstall(8).

   To display the NIC configuration, enter the following command:

 % ifconfig
 dc0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
         options=80008<VLAN_MTU,LINKSTATE>
         ether 00:a0:cc:da:da:da
         inet 192.168.1.3 netmask 0xffffff00 broadcast 192.168.1.255
         media: Ethernet autoselect (100baseTX <full-duplex>)
         status: active
 dc1: flags=8802<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
         options=80008<VLAN_MTU,LINKSTATE>
         ether 00:a0:cc:da:da:db
         inet 10.0.0.1 netmask 0xffffff00 broadcast 10.0.0.255
         media: Ethernet 10baseT/UTP
         status: no carrier
 lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
         options=3<RXCSUM,TXCSUM>
         inet6 fe80::1%lo0 prefixlen 64 scopeid 0x4
         inet6 ::1 prefixlen 128
         inet 127.0.0.1 netmask 0xff000000
         nd6 options=3<PERFORMNUD,ACCEPT_RTADV>

   In this example, the following devices were displayed:

     * dc0: The first Ethernet interface.

     * dc1: The second Ethernet interface.

     * lo0: The loopback device.

   FreeBSD uses the driver name followed by the order in which the card is
   detected at boot to name the NIC. For example, sis2 is the third NIC on
   the system using the sis(4) driver.

   In this example, dc0 is up and running. The key indicators are:

    1. UP means that the card is configured and ready.

    2. The card has an Internet (inet) address, 192.168.1.3.

    3. It has a valid subnet mask (netmask), where 0xffffff00 is the same as
       255.255.255.0.

    4. It has a valid broadcast address, 192.168.1.255.

    5. The MAC address of the card (ether) is 00:a0:cc:da:da:da.

    6. The physical media selection is on autoselection mode (media: Ethernet
       autoselect (100baseTX <full-duplex>)). In this example, dc1 is
       configured to run with 10baseT/UTP media. For more information on
       available media types for a driver, refer to its manual page.

    7. The status of the link (status) is active, indicating that the carrier
       signal is detected. For dc1, the status: no carrier status is normal
       when an Ethernet cable is not plugged into the card.

   If the ifconfig(8) output had shown something similar to:

 dc0: flags=8843<BROADCAST,SIMPLEX,MULTICAST> metric 0 mtu 1500
         options=80008<VLAN_MTU,LINKSTATE>
         ether 00:a0:cc:da:da:da
         media: Ethernet autoselect (100baseTX <full-duplex>)
         status: active

   it would indicate the card has not been configured.

   The card must be configured as root. The NIC configuration can be
   performed from the command line with ifconfig(8) but will not persist
   after a reboot unless the configuration is also added to /etc/rc.conf. If
   a DHCP server is present on the LAN, just add this line:

 ifconfig_dc0="DHCP"

   Replace dc0 with the correct value for the system.

   The line added, then, follow the instructions given in Section 12.5.3,
   "Testing and Troubleshooting".

  Note:

   If the network was configured during installation, some entries for the
   NIC(s) may be already present. Double check /etc/rc.conf before adding any
   lines.

   If there is no DHCP server, the NIC(s) must be configured manually. Add a
   line for each NIC present on the system, as seen in this example:

 ifconfig_dc0="inet 192.168.1.3 netmask 255.255.255.0"
 ifconfig_dc1="inet 10.0.0.1 netmask 255.255.255.0 media 10baseT/UTP"

   Replace dc0 and dc1 and the IP address information with the correct values
   for the system. Refer to the man page for the driver, ifconfig(8), and
   rc.conf(5) for more details about the allowed options and the syntax of
   /etc/rc.conf.

   If the network is not using DNS, edit /etc/hosts to add the names and IP
   addresses of the hosts on the LAN, if they are not already there. For more
   information, refer to hosts(5) and to /usr/share/examples/etc/hosts.

  Note:

   If there is no DHCP server and access to the Internet is needed, manually
   configure the default gateway and the nameserver:

 # echo 'defaultrouter="your_default_router"' >> /etc/rc.conf
 # echo 'nameserver your_DNS_server' >> /etc/resolv.conf

  12.5.3. Testing and Troubleshooting

   Once the necessary changes to /etc/rc.conf are saved, a reboot can be used
   to test the network configuration and to verify that the system restarts
   without any configuration errors. Alternatively, apply the settings to the
   networking system with this command:

 # service netif restart

  Note:

   If a default gateway has been set in /etc/rc.conf, also issue this
   command:

 # service routing restart

   Once the networking system has been relaunched, test the NICs.

    12.5.3.1. Testing the Ethernet Card

   To verify that an Ethernet card is configured correctly, ping(8) the
   interface itself, and then ping(8) another machine on the LAN:

 % ping -c5 192.168.1.3
 PING 192.168.1.3 (192.168.1.3): 56 data bytes
 64 bytes from 192.168.1.3: icmp_seq=0 ttl=64 time=0.082 ms
 64 bytes from 192.168.1.3: icmp_seq=1 ttl=64 time=0.074 ms
 64 bytes from 192.168.1.3: icmp_seq=2 ttl=64 time=0.076 ms
 64 bytes from 192.168.1.3: icmp_seq=3 ttl=64 time=0.108 ms
 64 bytes from 192.168.1.3: icmp_seq=4 ttl=64 time=0.076 ms

 --- 192.168.1.3 ping statistics ---
 5 packets transmitted, 5 packets received, 0% packet loss
 round-trip min/avg/max/stddev = 0.074/0.083/0.108/0.013 ms

 % ping -c5 192.168.1.2
 PING 192.168.1.2 (192.168.1.2): 56 data bytes
 64 bytes from 192.168.1.2: icmp_seq=0 ttl=64 time=0.726 ms
 64 bytes from 192.168.1.2: icmp_seq=1 ttl=64 time=0.766 ms
 64 bytes from 192.168.1.2: icmp_seq=2 ttl=64 time=0.700 ms
 64 bytes from 192.168.1.2: icmp_seq=3 ttl=64 time=0.747 ms
 64 bytes from 192.168.1.2: icmp_seq=4 ttl=64 time=0.704 ms

 --- 192.168.1.2 ping statistics ---
 5 packets transmitted, 5 packets received, 0% packet loss
 round-trip min/avg/max/stddev = 0.700/0.729/0.766/0.025 ms

   To test network resolution, use the host name instead of the IP address.
   If there is no DNS server on the network, /etc/hosts must first be
   configured. To this purpose, edit /etc/hosts to add the names and IP
   addresses of the hosts on the LAN, if they are not already there. For more
   information, refer to hosts(5) and to /usr/share/examples/etc/hosts.

    12.5.3.2. Troubleshooting

   When troubleshooting hardware and software configurations, check the
   simple things first. Is the network cable plugged in? Are the network
   services properly configured? Is the firewall configured correctly? Is the
   NIC supported by FreeBSD? Before sending a bug report, always check the
   Hardware Notes, update the version of FreeBSD to the latest STABLE
   version, check the mailing list archives, and search the Internet.

   If the card works, yet performance is poor, read through tuning(7). Also,
   check the network configuration as incorrect network settings can cause
   slow connections.

   Some users experience one or two device timeout messages, which is normal
   for some cards. If they continue, or are bothersome, determine if the
   device is conflicting with another device. Double check the cable
   connections. Consider trying another card.

   To resolve watchdog timeout errors, first check the network cable. Many
   cards require a PCI slot which supports bus mastering. On some old
   motherboards, only one PCI slot allows it, usually slot 0. Check the NIC
   and the motherboard documentation to determine if that may be the problem.

   No route to host messages occur if the system is unable to route a packet
   to the destination host. This can happen if no default route is specified
   or if a cable is unplugged. Check the output of netstat -rn and make sure
   there is a valid route to the host. If there is not, read Section 32.2,
   "Gateways and Routes".

   ping: sendto: Permission denied error messages are often caused by a
   misconfigured firewall. If a firewall is enabled on FreeBSD but no rules
   have been defined, the default policy is to deny all traffic, even
   ping(8). Refer to Chapter 31, Firewalls for more information.

   Sometimes performance of the card is poor or below average. In these
   cases, try setting the media selection mode from autoselect to the correct
   media selection. While this works for most hardware, it may or may not
   resolve the issue. Again, check all the network settings, and refer to
   tuning(7).

12.6. Virtual Hosts

   A common use of FreeBSD is virtual site hosting, where one server appears
   to the network as many servers. This is achieved by assigning multiple
   network addresses to a single interface.

   A given network interface has one "real" address, and may have any number
   of "alias" addresses. These aliases are normally added by placing alias
   entries in /etc/rc.conf, as seen in this example:

 ifconfig_fxp0_alias0="inet xxx.xxx.xxx.xxx netmask xxx.xxx.xxx.xxx"

   Alias entries must start with alias0 using a sequential number such as
   alias0, alias1, and so on. The configuration process will stop at the
   first missing number.

   The calculation of alias netmasks is important. For a given interface,
   there must be one address which correctly represents the network's
   netmask. Any other addresses which fall within this network must have a
   netmask of all 1s, expressed as either 255.255.255.255 or 0xffffffff.

   For example, consider the case where the fxp0 interface is connected to
   two networks: 10.1.1.0 with a netmask of 255.255.255.0 and 202.0.75.16
   with a netmask of 255.255.255.240. The system is to be configured to
   appear in the ranges 10.1.1.1 through 10.1.1.5 and 202.0.75.17 through
   202.0.75.20. Only the first address in a given network range should have a
   real netmask. All the rest (10.1.1.2 through 10.1.1.5 and 202.0.75.18
   through 202.0.75.20) must be configured with a netmask of 255.255.255.255.

   The following /etc/rc.conf entries configure the adapter correctly for
   this scenario:

 ifconfig_fxp0="inet 10.1.1.1 netmask 255.255.255.0"
 ifconfig_fxp0_alias0="inet 10.1.1.2 netmask 255.255.255.255"
 ifconfig_fxp0_alias1="inet 10.1.1.3 netmask 255.255.255.255"
 ifconfig_fxp0_alias2="inet 10.1.1.4 netmask 255.255.255.255"
 ifconfig_fxp0_alias3="inet 10.1.1.5 netmask 255.255.255.255"
 ifconfig_fxp0_alias4="inet 202.0.75.17 netmask 255.255.255.240"
 ifconfig_fxp0_alias5="inet 202.0.75.18 netmask 255.255.255.255"
 ifconfig_fxp0_alias6="inet 202.0.75.19 netmask 255.255.255.255"
 ifconfig_fxp0_alias7="inet 202.0.75.20 netmask 255.255.255.255"

   A simpler way to express this is with a space-separated list of IP address
   ranges. The first address will be given the indicated subnet mask and the
   additional addresses will have a subnet mask of 255.255.255.255.

 ifconfig_fxp0_aliases="inet 10.1.1.1-5/24 inet 202.0.75.17-20/28"

12.7. Configuring System Logging

   Contributed by Niclas Zeising.

   Generating and reading system logs is an important aspect of system
   administration. The information in system logs can be used to detect
   hardware and software issues as well as application and system
   configuration errors. This information also plays an important role in
   security auditing and incident response. Most system daemons and
   applications will generate log entries.

   FreeBSD provides a system logger, syslogd, to manage logging. By default,
   syslogd is started when the system boots. This is controlled by the
   variable syslogd_enable in /etc/rc.conf. There are numerous application
   arguments that can be set using syslogd_flags in /etc/rc.conf. Refer to
   syslogd(8) for more information on the available arguments.

   This section describes how to configure the FreeBSD system logger for both
   local and remote logging and how to perform log rotation and log
   management.

  12.7.1. Configuring Local Logging

   The configuration file, /etc/syslog.conf, controls what syslogd does with
   log entries as they are received. There are several parameters to control
   the handling of incoming events. The facility describes which subsystem
   generated the message, such as the kernel or a daemon, and the level
   describes the severity of the event that occurred. This makes it possible
   to configure if and where a log message is logged, depending on the
   facility and level. It is also possible to take action depending on the
   application that sent the message, and in the case of remote logging, the
   hostname of the machine generating the logging event.

   This configuration file contains one line per action, where the syntax for
   each line is a selector field followed by an action field. The syntax of
   the selector field is facility.level which will match log messages from
   facility at level level or higher. It is also possible to add an optional
   comparison flag before the level to specify more precisely what is logged.
   Multiple selector fields can be used for the same action, and are
   separated with a semicolon (;). Using * will match everything. The action
   field denotes where to send the log message, such as to a file or remote
   log host. As an example, here is the default syslog.conf from FreeBSD:

 # $FreeBSD$
 #
 #       Spaces ARE valid field separators in this file. However,
 #       other *nix-like systems still insist on using tabs as field
 #       separators. If you are sharing this file between systems, you
 #       may want to use only tabs as field separators here.
 #       Consult the syslog.conf(5) manpage.
 *.err;kern.warning;auth.notice;mail.crit                /dev/console
 *.notice;authpriv.none;kern.debug;lpr.info;mail.crit;news.err   /var/log/messages
 security.*                                      /var/log/security
 auth.info;authpriv.info                         /var/log/auth.log
 mail.info                                       /var/log/maillog
 lpr.info                                        /var/log/lpd-errs
 ftp.info                                        /var/log/xferlog
 cron.*                                          /var/log/cron
 !-devd
 *.=debug                                        /var/log/debug.log
 *.emerg                                         *
 # uncomment this to log all writes to /dev/console to /var/log/console.log
 #console.info                                   /var/log/console.log
 # uncomment this to enable logging of all log messages to /var/log/all.log
 # touch /var/log/all.log and chmod it to mode 600 before it will work
 #*.*                                            /var/log/all.log
 # uncomment this to enable logging to a remote loghost named loghost
 #*.*                                            @loghost
 # uncomment these if you're running inn
 # news.crit                                     /var/log/news/news.crit
 # news.err                                      /var/log/news/news.err
 # news.notice                                   /var/log/news/news.notice
 # Uncomment this if you wish to see messages produced by devd
 # !devd
 # *.>=info
 !ppp
 *.*                                             /var/log/ppp.log
 !*

   In this example:

     * Line 8 matches all messages with a level of err or higher, as well as
       kern.warning, auth.notice and mail.crit, and sends these log messages
       to the console (/dev/console).

     * Line 12 matches all messages from the mail facility at level info or
       above and logs the messages to /var/log/maillog.

     * Line 17 uses a comparison flag (=) to only match messages at level
       debug and logs them to /var/log/debug.log.

     * Line 33 is an example usage of a program specification. This makes the
       rules following it only valid for the specified program. In this case,
       only the messages generated by ppp are logged to /var/log/ppp.log.

   The available levels, in order from most to least critical are emerg,
   alert, crit, err, warning, notice, info, and debug.

   The facilities, in no particular order, are auth, authpriv, console, cron,
   daemon, ftp, kern, lpr, mail, mark, news, security, syslog, user, uucp,
   and local0 through local7. Be aware that other operating systems might
   have different facilities.

   To log everything of level notice and higher to /var/log/daemon.log, add
   the following entry:

 daemon.notice                                        /var/log/daemon.log

   For more information about the different levels and facilities, refer to
   syslog(3) and syslogd(8). For more information about /etc/syslog.conf, its
   syntax, and more advanced usage examples, see syslog.conf(5).

  12.7.2. Log Management and Rotation

   Log files can grow quickly, taking up disk space and making it more
   difficult to locate useful information. Log management attempts to
   mitigate this. In FreeBSD, newsyslog is used to manage log files. This
   built-in program periodically rotates and compresses log files, and
   optionally creates missing log files and signals programs when log files
   are moved. The log files may be generated by syslogd or by any other
   program which generates log files. While newsyslog is normally run from
   cron(8), it is not a system daemon. In the default configuration, it runs
   every hour.

   To know which actions to take, newsyslog reads its configuration file,
   /etc/newsyslog.conf. This file contains one line for each log file that
   newsyslog manages. Each line states the file owner, permissions, when to
   rotate that file, optional flags that affect log rotation, such as
   compression, and programs to signal when the log is rotated. Here is the
   default configuration in FreeBSD:

 # configuration file for newsyslog
 # $FreeBSD$
 #
 # Entries which do not specify the '/pid_file' field will cause the
 # syslogd process to be signalled when that log file is rotated.  This
 # action is only appropriate for log files which are written to by the
 # syslogd process (ie, files listed in /etc/syslog.conf).  If there
 # is no process which needs to be signalled when a given log file is
 # rotated, then the entry for that file should include the 'N' flag.
 #
 # The 'flags' field is one or more of the letters: BCDGJNUXZ or a '-'.
 #
 # Note: some sites will want to select more restrictive protections than the
 # defaults.  In particular, it may be desirable to switch many of the 644
 # entries to 640 or 600.  For example, some sites will consider the
 # contents of maillog, messages, and lpd-errs to be confidential.  In the
 # future, these defaults may change to more conservative ones.
 #
 # logfilename          [owner:group]    mode count size when  flags [/pid_file] [sig_num]
 /var/log/all.log                        600  7     *    @T00  J
 /var/log/amd.log                        644  7     100  *     J
 /var/log/auth.log                       600  7     100  @0101T JC
 /var/log/console.log                    600  5     100  *     J
 /var/log/cron                           600  3     100  *     JC
 /var/log/daily.log                      640  7     *    @T00  JN
 /var/log/debug.log                      600  7     100  *     JC
 /var/log/kerberos.log                   600  7     100  *     J
 /var/log/lpd-errs                       644  7     100  *     JC
 /var/log/maillog                        640  7     *    @T00  JC
 /var/log/messages                       644  5     100  @0101T JC
 /var/log/monthly.log                    640  12    *    $M1D0 JN
 /var/log/pflog                          600  3     100  *     JB    /var/run/pflogd.pid
 /var/log/ppp.log        root:network    640  3     100  *     JC
 /var/log/devd.log                       644  3     100  *     JC
 /var/log/security                       600  10    100  *     JC
 /var/log/sendmail.st                    640  10    *    168   B
 /var/log/utx.log                        644  3     *    @01T05 B
 /var/log/weekly.log                     640  5     1    $W6D0 JN
 /var/log/xferlog                        600  7     100  *     JC

   Each line starts with the name of the log to be rotated, optionally
   followed by an owner and group for both rotated and newly created files.
   The mode field sets the permissions on the log file and count denotes how
   many rotated log files should be kept. The size and when fields tell
   newsyslog when to rotate the file. A log file is rotated when either its
   size is larger than the size field or when the time in the when field has
   passed. An asterisk (*) means that this field is ignored. The flags field
   gives further instructions, such as how to compress the rotated file or to
   create the log file if it is missing. The last two fields are optional and
   specify the name of the Process ID (PID) file of a process and a signal
   number to send to that process when the file is rotated.

   For more information on all fields, valid flags, and how to specify the
   rotation time, refer to newsyslog.conf(5). Since newsyslog is run from
   cron(8), it cannot rotate files more often than it is scheduled to run
   from cron(8).

  12.7.3. Configuring Remote Logging

   Contributed by Tom Rhodes.

   Monitoring the log files of multiple hosts can become unwieldy as the
   number of systems increases. Configuring centralized logging can reduce
   some of the administrative burden of log file administration.

   In FreeBSD, centralized log file aggregation, merging, and rotation can be
   configured using syslogd and newsyslog. This section demonstrates an
   example configuration, where host A, named logserv.example.com, will
   collect logging information for the local network. Host B, named
   logclient.example.com, will be configured to pass logging information to
   the logging server.

    12.7.3.1. Log Server Configuration

   A log server is a system that has been configured to accept logging
   information from other hosts. Before configuring a log server, check the
   following:

     * If there is a firewall between the logging server and any logging
       clients, ensure that the firewall ruleset allows UDP port 514 for both
       the clients and the server.

     * The logging server and all client machines must have forward and
       reverse entries in the local DNS. If the network does not have a DNS
       server, create entries in each system's /etc/hosts. Proper name
       resolution is required so that log entries are not rejected by the
       logging server.

   On the log server, edit /etc/syslog.conf to specify the name of the client
   to receive log entries from, the logging facility to be used, and the name
   of the log to store the host's log entries. This example adds the hostname
   of B, logs all facilities, and stores the log entries in
   /var/log/logclient.log.

   Example 12.1. Sample Log Server Configuration

 +logclient.example.com
 *.*     /var/log/logclient.log

   When adding multiple log clients, add a similar two-line entry for each
   client. More information about the available facilities may be found in
   syslog.conf(5).

   Next, configure /etc/rc.conf:

 syslogd_enable="YES"
 syslogd_flags="-a logclient.example.com -v -v"

   The first entry starts syslogd at system boot. The second entry allows log
   entries from the specified client. The -v -v increases the verbosity of
   logged messages. This is useful for tweaking facilities as administrators
   are able to see what type of messages are being logged under each
   facility.

   Multiple -a options may be specified to allow logging from multiple
   clients. IP addresses and whole netblocks may also be specified. Refer to
   syslogd(8) for a full list of possible options.

   Finally, create the log file:

 # touch /var/log/logclient.log

   At this point, syslogd should be restarted and verified:

 # service syslogd restart
 # pgrep syslog

   If a PID is returned, the server restarted successfully, and client
   configuration can begin. If the server did not restart, consult
   /var/log/messages for the error.

    12.7.3.2. Log Client Configuration

   A logging client sends log entries to a logging server on the network. The
   client also keeps a local copy of its own logs.

   Once a logging server has been configured, edit /etc/rc.conf on the
   logging client:

 syslogd_enable="YES"
 syslogd_flags="-s -v -v"

   The first entry enables syslogd on boot up. The second entry prevents logs
   from being accepted by this client from other hosts (-s) and increases the
   verbosity of logged messages.

   Next, define the logging server in the client's /etc/syslog.conf. In this
   example, all logged facilities are sent to a remote system, denoted by the
   @ symbol, with the specified hostname:

 *.*             @logserv.example.com

   After saving the edit, restart syslogd for the changes to take effect:

 # service syslogd restart

   To test that log messages are being sent across the network, use logger(1)
   on the client to send a message to syslogd:

 # logger "Test message from logclient"

   This message should now exist both in /var/log/messages on the client and
   /var/log/logclient.log on the log server.

    12.7.3.3. Debugging Log Servers

   If no messages are being received on the log server, the cause is most
   likely a network connectivity issue, a hostname resolution issue, or a
   typo in a configuration file. To isolate the cause, ensure that both the
   logging server and the logging client are able to ping each other using
   the hostname specified in their /etc/rc.conf. If this fails, check the
   network cabling, the firewall ruleset, and the hostname entries in the DNS
   server or /etc/hosts on both the logging server and clients. Repeat until
   the ping is successful from both hosts.

   If the ping succeeds on both hosts but log messages are still not being
   received, temporarily increase logging verbosity to narrow down the
   configuration issue. In the following example, /var/log/logclient.log on
   the logging server is empty and /var/log/messages on the logging client
   does not indicate a reason for the failure. To increase debugging output,
   edit the syslogd_flags entry on the logging server and issue a restart:

 syslogd_flags="-d -a logclient.example.com -v -v"

 # service syslogd restart

   Debugging data similar to the following will flash on the console
   immediately after the restart:

 logmsg: pri 56, flags 4, from logserv.example.com, msg syslogd: restart
 syslogd: restarted
 logmsg: pri 6, flags 4, from logserv.example.com, msg syslogd: kernel boot file is /boot/kernel/kernel
 Logging to FILE /var/log/messages
 syslogd: kernel boot file is /boot/kernel/kernel
 cvthname(192.168.1.10)
 validate: dgram from IP 192.168.1.10, port 514, name logclient.example.com;
 rejected in rule 0 due to name mismatch.

   In this example, the log messages are being rejected due to a typo which
   results in a hostname mismatch. The client's hostname should be logclient,
   not logclien. Fix the typo, issue a restart, and verify the results:

 # service syslogd restart
 logmsg: pri 56, flags 4, from logserv.example.com, msg syslogd: restart
 syslogd: restarted
 logmsg: pri 6, flags 4, from logserv.example.com, msg syslogd: kernel boot file is /boot/kernel/kernel
 syslogd: kernel boot file is /boot/kernel/kernel
 logmsg: pri 166, flags 17, from logserv.example.com,
 msg Dec 10 20:55:02 <syslog.err> logserv.example.com syslogd: exiting on signal 2
 cvthname(192.168.1.10)
 validate: dgram from IP 192.168.1.10, port 514, name logclient.example.com;
 accepted in rule 0.
 logmsg: pri 15, flags 0, from logclient.example.com, msg Dec 11 02:01:28 trhodes: Test message 2
 Logging to FILE /var/log/logclient.log
 Logging to FILE /var/log/messages

   At this point, the messages are being properly received and placed in the
   correct file.

    12.7.3.4. Security Considerations

   As with any network service, security requirements should be considered
   before implementing a logging server. Log files may contain sensitive data
   about services enabled on the local host, user accounts, and configuration
   data. Network data sent from the client to the server will not be
   encrypted or password protected. If a need for encryption exists, consider
   using security/stunnel, which will transmit the logging data over an
   encrypted tunnel.

   Local security is also an issue. Log files are not encrypted during use or
   after log rotation. Local users may access log files to gain additional
   insight into system configuration. Setting proper permissions on log files
   is critical. The built-in log rotator, newsyslog, supports setting
   permissions on newly created and rotated log files. Setting log files to
   mode 600 should prevent unwanted access by local users. Refer to
   newsyslog.conf(5) for additional information.

12.8. Configuration Files

  12.8.1. /etc Layout

   There are a number of directories in which configuration information is
   kept. These include:

   /etc                Generic system-specific configuration information.     
   /etc/defaults       Default versions of system configuration files.        
   /etc/mail           Extra sendmail(8) configuration and other MTA          
                       configuration files.                                   
   /etc/ppp            Configuration for both user- and kernel-ppp programs.  
   /usr/local/etc      Configuration files for installed applications. May    
                       contain per-application subdirectories.                
   /usr/local/etc/rc.d rc(8) scripts for installed applications.              
                       Automatically generated system-specific database       
   /var/db             files, such as the package database and the locate(1)  
                       database.                                              

  12.8.2. Hostnames

    12.8.2.1. /etc/resolv.conf

   How a FreeBSD system accesses the Internet Domain Name System (DNS) is
   controlled by resolv.conf(5).

   The most common entries to /etc/resolv.conf are:

              The IP address of a name server the resolver should query. The  
   nameserver servers are queried in the order listed with a maximum of       
              three.                                                          
   search     Search list for hostname lookup. This is normally determined by 
              the domain of the local hostname.                               
   domain     The local domain name.                                          

   A typical /etc/resolv.conf looks like this:

 search example.com
 nameserver 147.11.1.11
 nameserver 147.11.100.30

  Note:

   Only one of the search and domain options should be used.

   When using DHCP, dhclient(8) usually rewrites /etc/resolv.conf with
   information received from the DHCP server.

    12.8.2.2. /etc/hosts

   /etc/hosts is a simple text database which works in conjunction with DNS
   and NIS to provide host name to IP address mappings. Entries for local
   computers connected via a LAN can be added to this file for simplistic
   naming purposes instead of setting up a named(8) server. Additionally,
   /etc/hosts can be used to provide a local record of Internet names,
   reducing the need to query external DNS servers for commonly accessed
   names.

 # $FreeBSD$
 #
 #
 # Host Database
 #
 # This file should contain the addresses and aliases for local hosts that
 # share this file.  Replace 'my.domain' below with the domainname of your
 # machine.
 #
 # In the presence of the domain name service or NIS, this file may
 # not be consulted at all; see /etc/nsswitch.conf for the resolution order.
 #
 #
 ::1                     localhost localhost.my.domain
 127.0.0.1               localhost localhost.my.domain
 #
 # Imaginary network.
 #10.0.0.2               myname.my.domain myname
 #10.0.0.3               myfriend.my.domain myfriend
 #
 # According to RFC 1918, you can use the following IP networks for
 # private nets which will never be connected to the Internet:
 #
 #       10.0.0.0        -   10.255.255.255
 #       172.16.0.0      -   172.31.255.255
 #       192.168.0.0     -   192.168.255.255
 #
 # In case you want to be able to connect to the Internet, you need
 # real official assigned numbers.  Do not try to invent your own network
 # numbers but instead get one from your network provider (if any) or
 # from your regional registry (ARIN, APNIC, LACNIC, RIPE NCC, or AfriNIC.)
 #

   The format of /etc/hosts is as follows:

 [Internet address] [official hostname] [alias1] [alias2] ...

   For example:

 10.0.0.1 myRealHostname.example.com myRealHostname foobar1 foobar2

   Consult hosts(5) for more information.

12.9. Tuning with sysctl(8)

   sysctl(8) is used to make changes to a running FreeBSD system. This
   includes many advanced options of the TCP/IP stack and virtual memory
   system that can dramatically improve performance for an experienced system
   administrator. Over five hundred system variables can be read and set
   using sysctl(8).

   At its core, sysctl(8) serves two functions: to read and to modify system
   settings.

   To view all readable variables:

 % sysctl -a

   To read a particular variable, specify its name:

 % sysctl kern.maxproc
 kern.maxproc: 1044

   To set a particular variable, use the variable=value syntax:

 # sysctl kern.maxfiles=5000
 kern.maxfiles: 2088 -> 5000

   Settings of sysctl variables are usually either strings, numbers, or
   booleans, where a boolean is 1 for yes or 0 for no.

   To automatically set some variables each time the machine boots, add them
   to /etc/sysctl.conf. For more information, refer to sysctl.conf(5) and
   Section 12.9.1, "sysctl.conf".

  12.9.1. sysctl.conf

   The configuration file for sysctl(8), /etc/sysctl.conf, looks much like
   /etc/rc.conf. Values are set in a variable=value form. The specified
   values are set after the system goes into multi-user mode. Not all
   variables are settable in this mode.

   For example, to turn off logging of fatal signal exits and prevent users
   from seeing processes started by other users, the following tunables can
   be set in /etc/sysctl.conf:

 # Do not log fatal signal exits (e.g., sig 11)
 kern.logsigexit=0

 # Prevent users from seeing information about processes that
 # are being run under another UID.
 security.bsd.see_other_uids=0

  12.9.2. sysctl(8) Read-only

   Contributed by Tom Rhodes.

   In some cases it may be desirable to modify read-only sysctl(8) values,
   which will require a reboot of the system.

   For instance, on some laptop models the cardbus(4) device will not probe
   memory ranges and will fail with errors similar to:

 cbb0: Could not map register memory
 device_probe_and_attach: cbb0 attach returned 12

   The fix requires the modification of a read-only sysctl(8) setting. Add
   hw.pci.allow_unsupported_io_range=1 to /boot/loader.conf and reboot. Now
   cardbus(4) should work properly.

12.10. Tuning Disks

   The following section will discuss various tuning mechanisms and options
   which may be applied to disk devices. In many cases, disks with mechanical
   parts, such as SCSI drives, will be the bottleneck driving down the
   overall system performance. While a solution is to install a drive without
   mechanical parts, such as a solid state drive, mechanical drives are not
   going away anytime in the near future. When tuning disks, it is advisable
   to utilize the features of the iostat(8) command to test various changes
   to the system. This command will allow the user to obtain valuable
   information on system IO.

  12.10.1. Sysctl Variables

    12.10.1.1. vfs.vmiodirenable

   The vfs.vmiodirenable sysctl(8) variable may be set to either 0 (off) or 1
   (on). It is set to 1 by default. This variable controls how directories
   are cached by the system. Most directories are small, using just a single
   fragment (typically 1 K) in the file system and typically 512 bytes in the
   buffer cache. With this variable turned off, the buffer cache will only
   cache a fixed number of directories, even if the system has a huge amount
   of memory. When turned on, this sysctl(8) allows the buffer cache to use
   the VM page cache to cache the directories, making all the memory
   available for caching directories. However, the minimum in-core memory
   used to cache a directory is the physical page size (typically 4 K) rather
   than 512  bytes. Keeping this option enabled is recommended if the system
   is running any services which manipulate large numbers of files. Such
   services can include web caches, large mail systems, and news systems.
   Keeping this option on will generally not reduce performance, even with
   the wasted memory, but one should experiment to find out.

    12.10.1.2. vfs.write_behind

   The vfs.write_behind sysctl(8) variable defaults to 1 (on). This tells the
   file system to issue media writes as full clusters are collected, which
   typically occurs when writing large sequential files. This avoids
   saturating the buffer cache with dirty buffers when it would not benefit
   I/O performance. However, this may stall processes and under certain
   circumstances should be turned off.

    12.10.1.3. vfs.hirunningspace

   The vfs.hirunningspace sysctl(8) variable determines how much outstanding
   write I/O may be queued to disk controllers system-wide at any given
   instance. The default is usually sufficient, but on machines with many
   disks, try bumping it up to four or five megabytes. Setting too high a
   value which exceeds the buffer cache's write threshold can lead to bad
   clustering performance. Do not set this value arbitrarily high as higher
   write values may add latency to reads occurring at the same time.

   There are various other buffer cache and VM page cache related sysctl(8)
   values. Modifying these values is not recommended as the VM system does a
   good job of automatically tuning itself.

    12.10.1.4. vm.swap_idle_enabled

   The vm.swap_idle_enabled sysctl(8) variable is useful in large multi-user
   systems with many active login users and lots of idle processes. Such
   systems tend to generate continuous pressure on free memory reserves.
   Turning this feature on and tweaking the swapout hysteresis (in idle
   seconds) via vm.swap_idle_threshold1 and vm.swap_idle_threshold2 depresses
   the priority of memory pages associated with idle processes more quickly
   then the normal pageout algorithm. This gives a helping hand to the
   pageout daemon. Only turn this option on if needed, because the tradeoff
   is essentially pre-page memory sooner rather than later which eats more
   swap and disk bandwidth. In a small system this option will have a
   determinable effect, but in a large system that is already doing moderate
   paging, this option allows the VM system to stage whole processes into and
   out of memory easily.

    12.10.1.5. hw.ata.wc

   Turning off IDE write caching reduces write bandwidth to IDE disks, but
   may sometimes be necessary due to data consistency issues introduced by
   hard drive vendors. The problem is that some IDE drives lie about when a
   write completes. With IDE write caching turned on, IDE hard drives write
   data to disk out of order and will sometimes delay writing some blocks
   indefinitely when under heavy disk load. A crash or power failure may
   cause serious file system corruption. Check the default on the system by
   observing the hw.ata.wc sysctl(8) variable. If IDE write caching is turned
   off, one can set this read-only variable to 1 in /boot/loader.conf in
   order to enable it at boot time.

   For more information, refer to ata(4).

    12.10.1.6. SCSI_DELAY (kern.cam.scsi_delay)

   The SCSI_DELAY kernel configuration option may be used to reduce system
   boot times. The defaults are fairly high and can be responsible for 15
   seconds of delay in the boot process. Reducing it to 5 seconds usually
   works with modern drives. The kern.cam.scsi_delay boot time tunable should
   be used. The tunable and kernel configuration option accept values in
   terms of milliseconds and not seconds.

  12.10.2. Soft Updates

   To fine-tune a file system, use tunefs(8). This program has many different
   options. To toggle Soft Updates on and off, use:

 # tunefs -n enable /filesystem
 # tunefs -n disable /filesystem

   A file system cannot be modified with tunefs(8) while it is mounted. A
   good time to enable Soft Updates is before any partitions have been
   mounted, in single-user mode.

   Soft Updates is recommended for UFS file systems as it drastically
   improves meta-data performance, mainly file creation and deletion, through
   the use of a memory cache. There are two downsides to Soft Updates to be
   aware of. First, Soft Updates guarantee file system consistency in the
   case of a crash, but could easily be several seconds or even a minute
   behind updating the physical disk. If the system crashes, unwritten data
   may be lost. Secondly, Soft Updates delay the freeing of file system
   blocks. If the root file system is almost full, performing a major update,
   such as make installworld, can cause the file system to run out of space
   and the update to fail.

    12.10.2.1. More Details About Soft Updates

   Meta-data updates are updates to non-content data like inodes or
   directories. There are two traditional approaches to writing a file
   system's meta-data back to disk.

   Historically, the default behavior was to write out meta-data updates
   synchronously. If a directory changed, the system waited until the change
   was actually written to disk. The file data buffers (file contents) were
   passed through the buffer cache and backed up to disk later on
   asynchronously. The advantage of this implementation is that it operates
   safely. If there is a failure during an update, meta-data is always in a
   consistent state. A file is either created completely or not at all. If
   the data blocks of a file did not find their way out of the buffer cache
   onto the disk by the time of the crash, fsck(8) recognizes this and
   repairs the file system by setting the file length to 0. Additionally, the
   implementation is clear and simple. The disadvantage is that meta-data
   changes are slow. For example, rm -r touches all the files in a directory
   sequentially, but each directory change will be written synchronously to
   the disk. This includes updates to the directory itself, to the inode
   table, and possibly to indirect blocks allocated by the file. Similar
   considerations apply for unrolling large hierarchies using tar -x.

   The second approach is to use asynchronous meta-data updates. This is the
   default for a UFS file system mounted with mount -o async. Since all
   meta-data updates are also passed through the buffer cache, they will be
   intermixed with the updates of the file content data. The advantage of
   this implementation is there is no need to wait until each meta-data
   update has been written to disk, so all operations which cause huge
   amounts of meta-data updates work much faster than in the synchronous
   case. This implementation is still clear and simple, so there is a low
   risk for bugs creeping into the code. The disadvantage is that there is no
   guarantee for a consistent state of the file system. If there is a failure
   during an operation that updated large amounts of meta-data, like a power
   failure or someone pressing the reset button, the file system will be left
   in an unpredictable state. There is no opportunity to examine the state of
   the file system when the system comes up again as the data blocks of a
   file could already have been written to the disk while the updates of the
   inode table or the associated directory were not. It is impossible to
   implement a fsck(8) which is able to clean up the resulting chaos because
   the necessary information is not available on the disk. If the file system
   has been damaged beyond repair, the only choice is to reformat it and
   restore from backup.

   The usual solution for this problem is to implement dirty region logging,
   which is also referred to as journaling. Meta-data updates are still
   written synchronously, but only into a small region of the disk. Later on,
   they are moved to their proper location. Since the logging area is a
   small, contiguous region on the disk, there are no long distances for the
   disk heads to move, even during heavy operations, so these operations are
   quicker than synchronous updates. Additionally, the complexity of the
   implementation is limited, so the risk of bugs being present is low. A
   disadvantage is that all meta-data is written twice, once into the logging
   region and once to the proper location, so performance "pessimization"
   might result. On the other hand, in case of a crash, all pending meta-data
   operations can be either quickly rolled back or completed from the logging
   area after the system comes up again, resulting in a fast file system
   startup.

   Kirk McKusick, the developer of Berkeley FFS, solved this problem with
   Soft Updates. All pending meta-data updates are kept in memory and written
   out to disk in a sorted sequence ("ordered meta-data updates"). This has
   the effect that, in case of heavy meta-data operations, later updates to
   an item "catch" the earlier ones which are still in memory and have not
   already been written to disk. All operations are generally performed in
   memory before the update is written to disk and the data blocks are sorted
   according to their position so that they will not be on the disk ahead of
   their meta-data. If the system crashes, an implicit "log rewind" causes
   all operations which were not written to the disk appear as if they never
   happened. A consistent file system state is maintained that appears to be
   the one of 30 to 60 seconds earlier. The algorithm used guarantees that
   all resources in use are marked as such in their blocks and inodes. After
   a crash, the only resource allocation error that occurs is that resources
   are marked as "used" which are actually "free". fsck(8) recognizes this
   situation, and frees the resources that are no longer used. It is safe to
   ignore the dirty state of the file system after a crash by forcibly
   mounting it with mount -f. In order to free resources that may be unused,
   fsck(8) needs to be run at a later time. This is the idea behind the
   background fsck(8): at system startup time, only a snapshot of the file
   system is recorded and fsck(8) is run afterwards. All file systems can
   then be mounted "dirty", so the system startup proceeds in multi-user
   mode. Then, background fsck(8) is scheduled for all file systems where
   this is required, to free resources that may be unused. File systems that
   do not use Soft Updates still need the usual foreground fsck(8).

   The advantage is that meta-data operations are nearly as fast as
   asynchronous updates and are faster than logging, which has to write the
   meta-data twice. The disadvantages are the complexity of the code, a
   higher memory consumption, and some idiosyncrasies. After a crash, the
   state of the file system appears to be somewhat "older". In situations
   where the standard synchronous approach would have caused some zero-length
   files to remain after the fsck(8), these files do not exist at all with
   Soft Updates because neither the meta-data nor the file contents have been
   written to disk. Disk space is not released until the updates have been
   written to disk, which may take place some time after running rm(1). This
   may cause problems when installing large amounts of data on a file system
   that does not have enough free space to hold all the files twice.

12.11. Tuning Kernel Limits

  12.11.1. File/Process Limits

    12.11.1.1. kern.maxfiles

   The kern.maxfiles sysctl(8) variable can be raised or lowered based upon
   system requirements. This variable indicates the maximum number of file
   descriptors on the system. When the file descriptor table is full, file:
   table is full will show up repeatedly in the system message buffer, which
   can be viewed using dmesg(8).

   Each open file, socket, or fifo uses one file descriptor. A large-scale
   production server may easily require many thousands of file descriptors,
   depending on the kind and number of services running concurrently.

   In older FreeBSD releases, the default value of kern.maxfiles is derived
   from maxusers in the kernel configuration file. kern.maxfiles grows
   proportionally to the value of maxusers. When compiling a custom kernel,
   consider setting this kernel configuration option according to the use of
   the system. From this number, the kernel is given most of its pre-defined
   limits. Even though a production machine may not have 256 concurrent
   users, the resources needed may be similar to a high-scale web server.

   The read-only sysctl(8) variable kern.maxusers is automatically sized at
   boot based on the amount of memory available in the system, and may be
   determined at run-time by inspecting the value of kern.maxusers. Some
   systems require larger or smaller values of kern.maxusers and values of
   64, 128, and 256 are not uncommon. Going above 256 is not recommended
   unless a huge number of file descriptors is needed. Many of the tunable
   values set to their defaults by kern.maxusers may be individually
   overridden at boot-time or run-time in /boot/loader.conf. Refer to
   loader.conf(5) and /boot/defaults/loader.conf for more details and some
   hints.

   In older releases, the system will auto-tune maxusers if it is set to 0.
   [2]. When setting this option, set maxusers to at least 4, especially if
   the system runs Xorg or is used to compile software. The most important
   table set by maxusers is the maximum number of processes, which is set to
   20 + 16 * maxusers. If maxusers is set to 1, there can only be 36
   simultaneous processes, including the 18 or so that the system starts up
   at boot time and the 15 or so used by Xorg. Even a simple task like
   reading a manual page will start up nine processes to filter, decompress,
   and view it. Setting maxusers to 64 allows up to 1044 simultaneous
   processes, which should be enough for nearly all uses. If, however, the
   proc table full error is displayed when trying to start another program,
   or a server is running with a large number of simultaneous users, increase
   the number and rebuild.

  Note:

   maxusers does not limit the number of users which can log into the
   machine. It instead sets various table sizes to reasonable values
   considering the maximum number of users on the system and how many
   processes each user will be running.

    12.11.1.2. kern.ipc.soacceptqueue

   The kern.ipc.soacceptqueue sysctl(8) variable limits the size of the
   listen queue for accepting new TCP connections. The default value of 128
   is typically too low for robust handling of new connections on a heavily
   loaded web server. For such environments, it is recommended to increase
   this value to 1024 or higher. A service such as sendmail(8), or Apache may
   itself limit the listen queue size, but will often have a directive in its
   configuration file to adjust the queue size. Large listen queues do a
   better job of avoiding Denial of Service (DoS) attacks.

  12.11.2. Network Limits

   The NMBCLUSTERS kernel configuration option dictates the amount of network
   Mbufs available to the system. A heavily-trafficked server with a low
   number of Mbufs will hinder performance. Each cluster represents
   approximately 2 K of memory, so a value of 1024 represents 2 megabytes of
   kernel memory reserved for network buffers. A simple calculation can be
   done to figure out how many are needed. A web server which maxes out at
   1000 simultaneous connections where each connection uses a 6 K receive and
   16 K send buffer, requires approximately 32 MB worth of network buffers to
   cover the web server. A good rule of thumb is to multiply by 2, so
   2x32 MB / 2 KB = 64 MB / 2 kB = 32768. Values between 4096 and 32768 are
   recommended for machines with greater amounts of memory. Never specify an
   arbitrarily high value for this parameter as it could lead to a boot time
   crash. To observe network cluster usage, use -m with netstat(1).

   The kern.ipc.nmbclusters loader tunable should be used to tune this at
   boot time. Only older versions of FreeBSD will require the use of the
   NMBCLUSTERS kernel config(8) option.

   For busy servers that make extensive use of the sendfile(2) system call,
   it may be necessary to increase the number of sendfile(2) buffers via the
   NSFBUFS kernel configuration option or by setting its value in
   /boot/loader.conf (see loader(8) for details). A common indicator that
   this parameter needs to be adjusted is when processes are seen in the
   sfbufa state. The sysctl(8) variable kern.ipc.nsfbufs is read-only. This
   parameter nominally scales with kern.maxusers, however it may be necessary
   to tune accordingly.

  Important:

   Even though a socket has been marked as non-blocking, calling sendfile(2)
   on the non-blocking socket may result in the sendfile(2) call blocking
   until enough struct sf_buf's are made available.

    12.11.2.1. net.inet.ip.portrange.*

   The net.inet.ip.portrange.* sysctl(8) variables control the port number
   ranges automatically bound to TCP and UDP sockets. There are three ranges:
   a low range, a default range, and a high range. Most network programs use
   the default range which is controlled by net.inet.ip.portrange.first and
   net.inet.ip.portrange.last, which default to 1024 and 5000, respectively.
   Bound port ranges are used for outgoing connections and it is possible to
   run the system out of ports under certain circumstances. This most
   commonly occurs when running a heavily loaded web proxy. The port range is
   not an issue when running a server which handles mainly incoming
   connections, such as a web server, or has a limited number of outgoing
   connections, such as a mail relay. For situations where there is a
   shortage of ports, it is recommended to increase
   net.inet.ip.portrange.last modestly. A value of 10000, 20000 or 30000 may
   be reasonable. Consider firewall effects when changing the port range.
   Some firewalls may block large ranges of ports, usually low-numbered
   ports, and expect systems to use higher ranges of ports for outgoing
   connections. For this reason, it is not recommended that the value of
   net.inet.ip.portrange.first be lowered.

    12.11.2.2. TCP Bandwidth Delay Product

   TCP bandwidth delay product limiting can be enabled by setting the
   net.inet.tcp.inflight.enable sysctl(8) variable to 1. This instructs the
   system to attempt to calculate the bandwidth delay product for each
   connection and limit the amount of data queued to the network to just the
   amount required to maintain optimum throughput.

   This feature is useful when serving data over modems, Gigabit Ethernet,
   high speed WAN links, or any other link with a high bandwidth delay
   product, especially when also using window scaling or when a large send
   window has been configured. When enabling this option, also set
   net.inet.tcp.inflight.debug to 0 to disable debugging. For production use,
   setting net.inet.tcp.inflight.min to at least 6144 may be beneficial.
   Setting high minimums may effectively disable bandwidth limiting,
   depending on the link. The limiting feature reduces the amount of data
   built up in intermediate route and switch packet queues and reduces the
   amount of data built up in the local host's interface queue. With fewer
   queued packets, interactive connections, especially over slow modems, will
   operate with lower Round Trip Times. This feature only effects server side
   data transmission such as uploading. It has no effect on data reception or
   downloading.

   Adjusting net.inet.tcp.inflight.stab is not recommended. This parameter
   defaults to 20, representing 2 maximal packets added to the bandwidth
   delay product window calculation. The additional window is required to
   stabilize the algorithm and improve responsiveness to changing conditions,
   but it can also result in higher ping(8) times over slow links, though
   still much lower than without the inflight algorithm. In such cases, try
   reducing this parameter to 15, 10, or 5 and reducing
   net.inet.tcp.inflight.min to a value such as 3500 to get the desired
   effect. Reducing these parameters should be done as a last resort only.

  12.11.3. Virtual Memory

    12.11.3.1. kern.maxvnodes

   A vnode is the internal representation of a file or directory. Increasing
   the number of vnodes available to the operating system reduces disk I/O.
   Normally, this is handled by the operating system and does not need to be
   changed. In some cases where disk I/O is a bottleneck and the system is
   running out of vnodes, this setting needs to be increased. The amount of
   inactive and free RAM will need to be taken into account.

   To see the current number of vnodes in use:

 # sysctl vfs.numvnodes
 vfs.numvnodes: 91349

   To see the maximum vnodes:

 # sysctl kern.maxvnodes
 kern.maxvnodes: 100000

   If the current vnode usage is near the maximum, try increasing
   kern.maxvnodes by a value of 1000. Keep an eye on the number of
   vfs.numvnodes. If it climbs up to the maximum again, kern.maxvnodes will
   need to be increased further. Otherwise, a shift in memory usage as
   reported by top(1) should be visible and more memory should be active.

12.12. Adding Swap Space

   Sometimes a system requires more swap space. This section describes two
   methods to increase swap space: adding swap to an existing partition or
   new hard drive, and creating a swap file on an existing partition.

   For information on how to encrypt swap space, which options exist, and why
   it should be done, refer to Section 18.13, "Encrypting Swap".

  12.12.1. Swap on a New Hard Drive or Existing Partition

   Adding a new hard drive for swap gives better performance than using a
   partition on an existing drive. Setting up partitions and hard drives is
   explained in Section 18.2, "Adding Disks" while Section 2.6.1, "Designing
   the Partition Layout" discusses partition layouts and swap partition size
   considerations.

   Use swapon to add a swap partition to the system. For example:

 # swapon /dev/ada1s1b

  Warning:

   It is possible to use any partition not currently mounted, even if it
   already contains data. Using swapon on a partition that contains data will
   overwrite and destroy that data. Make sure that the partition to be added
   as swap is really the intended partition before running swapon.

   To automatically add this swap partition on boot, add an entry to
   /etc/fstab:

 /dev/ada1s1b    none    swap    sw      0       0

   See fstab(5) for an explanation of the entries in /etc/fstab. More
   information about swapon can be found in swapon(8).

  12.12.2. Creating a Swap File

   These examples create a 512M swap file called /usr/swap0 instead of using
   a partition.

   Using swap files requires that the module needed by md(4) has either been
   built into the kernel or has been loaded before swap is enabled. See
   Chapter 8, Configuring the FreeBSD Kernel for information about building a
   custom kernel.

   Example 12.2. Creating a Swap File
    1. Create the swap file:

 # dd if=/dev/zero of=/usr/swap0 bs=1m count=512

    2. Set the proper permissions on the new file:

 # chmod 0600 /usr/swap0

    3. Inform the system about the swap file by adding a line to /etc/fstab:

 md99    none    swap    sw,file=/usr/swap0,late 0       0

       The md(4) device md99 is used, leaving lower device numbers available
       for interactive use.

    4. Swap space will be added on system startup. To add swap space
       immediately, use swapon(8):

 # swapon -aL

12.13. Power and Resource Management

   Written by Hiten Pandya and Tom Rhodes.

   It is important to utilize hardware resources in an efficient manner.
   Power and resource management allows the operating system to monitor
   system limits and to possibly provide an alert if the system temperature
   increases unexpectedly. An early specification for providing power
   management was the Advanced Power Management (APM) facility. APM controls
   the power usage of a system based on its activity. However, it was
   difficult and inflexible for operating systems to manage the power usage
   and thermal properties of a system. The hardware was managed by the BIOS
   and the user had limited configurability and visibility into the power
   management settings. The APM BIOS is supplied by the vendor and is
   specific to the hardware platform. An APM driver in the operating system
   mediates access to the APM Software Interface, which allows management of
   power levels.

   There are four major problems in APM. First, power management is done by
   the vendor-specific BIOS, separate from the operating system. For example,
   the user can set idle-time values for a hard drive in the APM BIOS so
   that, when exceeded, the BIOS spins down the hard drive without the
   consent of the operating system. Second, the APM logic is embedded in the
   BIOS, and it operates outside the scope of the operating system. This
   means that users can only fix problems in the APM BIOS by flashing a new
   one into the ROM, which is a dangerous procedure with the potential to
   leave the system in an unrecoverable state if it fails. Third, APM is a
   vendor-specific technology, meaning that there is a lot of duplication of
   efforts and bugs found in one vendor's BIOS may not be solved in others.
   Lastly, the APM BIOS did not have enough room to implement a sophisticated
   power policy or one that can adapt well to the purpose of the machine.

   The Plug and Play BIOS (PNPBIOS) was unreliable in many situations.
   PNPBIOS is 16-bit technology, so the operating system has to use 16-bit
   emulation in order to interface with PNPBIOS methods. FreeBSD provides an
   APM driver as APM should still be used for systems manufactured at or
   before the year 2000. The driver is documented in apm(4).

   The successor to APM is the Advanced Configuration and Power Interface
   (ACPI). ACPI is a standard written by an alliance of vendors to provide an
   interface for hardware resources and power management. It is a key element
   in Operating System-directed configuration and Power Management as it
   provides more control and flexibility to the operating system.

   This chapter demonstrates how to configure ACPI on FreeBSD. It then offers
   some tips on how to debug ACPI and how to submit a problem report
   containing debugging information so that developers can diagnosis and fix
   ACPI issues.

  12.13.1. Configuring ACPI

   In FreeBSD the acpi(4) driver is loaded by default at system boot and
   should not be compiled into the kernel. This driver cannot be unloaded
   after boot because the system bus uses it for various hardware
   interactions. However, if the system is experiencing problems, ACPI can be
   disabled altogether by rebooting after setting hint.acpi.0.disabled="1" in
   /boot/loader.conf or by setting this variable at the loader prompt, as
   described in Section 13.2.3, "Stage Three".

  Note:

   ACPI and APM cannot coexist and should be used separately. The last one to
   load will terminate if the driver notices the other is running.

   ACPI can be used to put the system into a sleep mode with acpiconf, the -s
   flag, and a number from 1 to 5. Most users only need 1 (quick suspend to
   RAM) or 3 (suspend to RAM). Option 5 performs a soft-off which is the same
   as running halt -p.

   Other options are available using sysctl. Refer to acpi(4) and acpiconf(8)
   for more information.

  12.13.2. Common Problems

   ACPI is present in all modern computers that conform to the ia32 (x86) and
   amd64 (AMD) architectures. The full standard has many features including
   CPU performance management, power planes control, thermal zones, various
   battery systems, embedded controllers, and bus enumeration. Most systems
   implement less than the full standard. For instance, a desktop system
   usually only implements bus enumeration while a laptop might have cooling
   and battery management support as well. Laptops also have suspend and
   resume, with their own associated complexity.

   An ACPI-compliant system has various components. The BIOS and chipset
   vendors provide various fixed tables, such as FADT, in memory that specify
   things like the APIC map (used for SMP), config registers, and simple
   configuration values. Additionally, a bytecode table, the Differentiated
   System Description Table DSDT, specifies a tree-like name space of devices
   and methods.

   The ACPI driver must parse the fixed tables, implement an interpreter for
   the bytecode, and modify device drivers and the kernel to accept
   information from the ACPI subsystem. For FreeBSD, Intel(R) has provided an
   interpreter (ACPI-CA) that is shared with Linux(R) and NetBSD. The path to
   the ACPI-CA source code is src/sys/contrib/dev/acpica. The glue code that
   allows ACPI-CA to work on FreeBSD is in src/sys/dev/acpica/Osd. Finally,
   drivers that implement various ACPI devices are found in
   src/sys/dev/acpica.

   For ACPI to work correctly, all the parts have to work correctly. Here are
   some common problems, in order of frequency of appearance, and some
   possible workarounds or fixes. If a fix does not resolve the issue, refer
   to Section 12.13.4, "Getting and Submitting Debugging Info" for
   instructions on how to submit a bug report.

    12.13.2.1. Mouse Issues

   In some cases, resuming from a suspend operation will cause the mouse to
   fail. A known work around is to add hint.psm.0.flags="0x3000" to
   /boot/loader.conf.

    12.13.2.2. Suspend/Resume

   ACPI has three suspend to RAM (STR) states, S1-S3, and one suspend to disk
   state (STD), called S4. STD can be implemented in two separate ways. The
   S4BIOS is a BIOS-assisted suspend to disk and S4OS is implemented entirely
   by the operating system. The normal state the system is in when plugged in
   but not powered up is "soft off" (S5).

   Use sysctl hw.acpi to check for the suspend-related items. These example
   results are from a Thinkpad:

 hw.acpi.supported_sleep_state: S3 S4 S5
 hw.acpi.s4bios: 0

   Use acpiconf -s to test S3, S4, and S5. An s4bios of one (1) indicates
   S4BIOS support instead of S4 operating system support.

   When testing suspend/resume, start with S1, if supported. This state is
   most likely to work since it does not require much driver support. No one
   has implemented S2, which is similar to S1. Next, try S3. This is the
   deepest STR state and requires a lot of driver support to properly
   reinitialize the hardware.

   A common problem with suspend/resume is that many device drivers do not
   save, restore, or reinitialize their firmware, registers, or device memory
   properly. As a first attempt at debugging the problem, try:

 # sysctl debug.bootverbose=1
 # sysctl debug.acpi.suspend_bounce=1
 # acpiconf -s 3

   This test emulates the suspend/resume cycle of all device drivers without
   actually going into S3 state. In some cases, problems such as losing
   firmware state, device watchdog time out, and retrying forever, can be
   captured with this method. Note that the system will not really enter S3
   state, which means devices may not lose power, and many will work fine
   even if suspend/resume methods are totally missing, unlike real S3 state.

   Harder cases require additional hardware, such as a serial port and cable
   for debugging through a serial console, a Firewire port and cable for
   using dcons(4), and kernel debugging skills.

   To help isolate the problem, unload as many drivers as possible. If it
   works, narrow down which driver is the problem by loading drivers until it
   fails again. Typically, binary drivers like nvidia.ko, display drivers,
   and USB will have the most problems while Ethernet interfaces usually work
   fine. If drivers can be properly loaded and unloaded, automate this by
   putting the appropriate commands in /etc/rc.suspend and /etc/rc.resume.
   Try setting hw.acpi.reset_video to 1 if the display is messed up after
   resume. Try setting longer or shorter values for hw.acpi.sleep_delay to
   see if that helps.

   Try loading a recent Linux(R) distribution to see if suspend/resume works
   on the same hardware. If it works on Linux(R), it is likely a FreeBSD
   driver problem. Narrowing down which driver causes the problem will assist
   developers in fixing the problem. Since the ACPI maintainers rarely
   maintain other drivers, such as sound or ATA, any driver problems should
   also be posted to the freebsd-current list and mailed to the driver
   maintainer. Advanced users can include debugging printf(3)s in a
   problematic driver to track down where in its resume function it hangs.

   Finally, try disabling ACPI and enabling APM instead. If suspend/resume
   works with APM, stick with APM, especially on older hardware (pre-2000).
   It took vendors a while to get ACPI support correct and older hardware is
   more likely to have BIOS problems with ACPI.

    12.13.2.3. System Hangs

   Most system hangs are a result of lost interrupts or an interrupt storm.
   Chipsets may have problems based on boot, how the BIOS configures
   interrupts before correctness of the APIC (MADT) table, and routing of the
   System Control Interrupt (SCI).

   Interrupt storms can be distinguished from lost interrupts by checking the
   output of vmstat -i and looking at the line that has acpi0. If the counter
   is increasing at more than a couple per second, there is an interrupt
   storm. If the system appears hung, try breaking to DDB (CTRL+ALT+ESC on
   console) and type show interrupts.

   When dealing with interrupt problems, try disabling APIC support with
   hint.apic.0.disabled="1" in /boot/loader.conf.

    12.13.2.4. Panics

   Panics are relatively rare for ACPI and are the top priority to be fixed.
   The first step is to isolate the steps to reproduce the panic, if
   possible, and get a backtrace. Follow the advice for enabling options DDB
   and setting up a serial console in Section 27.6.4, "Entering the DDB
   Debugger from the Serial Line" or setting up a dump partition. To get a
   backtrace in DDB, use tr. When handwriting the backtrace, get at least the
   last five and the top five lines in the trace.

   Then, try to isolate the problem by booting with ACPI disabled. If that
   works, isolate the ACPI subsystem by using various values of
   debug.acpi.disable. See acpi(4) for some examples.

    12.13.2.5. System Powers Up After Suspend or Shutdown

   First, try setting hw.acpi.disable_on_poweroff="0" in /boot/loader.conf.
   This keeps ACPI from disabling various events during the shutdown process.
   Some systems need this value set to 1 (the default) for the same reason.
   This usually fixes the problem of a system powering up spontaneously after
   a suspend or poweroff.

    12.13.2.6. BIOS Contains Buggy Bytecode

   Some BIOS vendors provide incorrect or buggy bytecode. This is usually
   manifested by kernel console messages like this:

 ACPI-1287: *** Error: Method execution failed [\\_SB_.PCI0.LPC0.FIGD._STA] \\
 (Node 0xc3f6d160), AE_NOT_FOUND

   Often, these problems may be resolved by updating the BIOS to the latest
   revision. Most console messages are harmless, but if there are other
   problems, like the battery status is not working, these messages are a
   good place to start looking for problems.

  12.13.3. Overriding the Default AML

   The BIOS bytecode, known as ACPI Machine Language (AML), is compiled from
   a source language called ACPI Source Language (ASL). The AML is found in
   the table known as the Differentiated System Description Table (DSDT).

   The goal of FreeBSD is for everyone to have working ACPI without any user
   intervention. Workarounds are still being developed for common mistakes
   made by BIOS vendors. The Microsoft(R) interpreter (acpi.sys and
   acpiec.sys) does not strictly check for adherence to the standard, and
   thus many BIOS vendors who only test ACPI under Windows(R) never fix their
   ASL. FreeBSD developers continue to identify and document which
   non-standard behavior is allowed by Microsoft(R)'s interpreter and
   replicate it so that FreeBSD can work without forcing users to fix the
   ASL.

   To help identify buggy behavior and possibly fix it manually, a copy can
   be made of the system's ASL. To copy the system's ASL to a specified file
   name, use acpidump with -t, to show the contents of the fixed tables, and
   -d, to disassemble the AML:

 # acpidump -td > my.asl

   Some AML versions assume the user is running Windows(R). To override this,
   set hw.acpi.osname="Windows 2009" in /boot/loader.conf, using the most
   recent Windows(R) version listed in the ASL.

   Other workarounds may require my.asl to be customized. If this file is
   edited, compile the new ASL using the following command. Warnings can
   usually be ignored, but errors are bugs that will usually prevent ACPI
   from working correctly.

 # iasl -f my.asl

   Including -f forces creation of the AML, even if there are errors during
   compilation. Some errors, such as missing return statements, are
   automatically worked around by the FreeBSD interpreter.

   The default output filename for iasl is DSDT.aml. Load this file instead
   of the BIOS's buggy copy, which is still present in flash memory, by
   editing /boot/loader.conf as follows:

 acpi_dsdt_load="YES"
 acpi_dsdt_name="/boot/DSDT.aml"

   Be sure to copy DSDT.aml to /boot, then reboot the system. If this fixes
   the problem, send a diff(1) of the old and new ASL to freebsd-acpi so that
   developers can work around the buggy behavior in acpica.

  12.13.4. Getting and Submitting Debugging Info

   Written by Nate Lawson.
   With contributions from Peter Schultz and Tom Rhodes.

   The ACPI driver has a flexible debugging facility. A set of subsystems and
   the level of verbosity can be specified. The subsystems to debug are
   specified as layers and are broken down into components
   (ACPI_ALL_COMPONENTS) and ACPI hardware support (ACPI_ALL_DRIVERS). The
   verbosity of debugging output is specified as the level and ranges from
   just report errors (ACPI_LV_ERROR) to everything (ACPI_LV_VERBOSE). The
   level is a bitmask so multiple options can be set at once, separated by
   spaces. In practice, a serial console should be used to log the output so
   it is not lost as the console message buffer flushes. A full list of the
   individual layers and levels is found in acpi(4).

   Debugging output is not enabled by default. To enable it, add options
   ACPI_DEBUG to the custom kernel configuration file if ACPI is compiled
   into the kernel. Add ACPI_DEBUG=1 to /etc/make.conf to enable it globally.
   If a module is used instead of a custom kernel, recompile just the acpi.ko
   module as follows:

 # cd /sys/modules/acpi/acpi && make clean && make ACPI_DEBUG=1

   Copy the compiled acpi.ko to /boot/kernel and add the desired level and
   layer to /boot/loader.conf. The entries in this example enable debug
   messages for all ACPI components and hardware drivers and output error
   messages at the least verbose level:

 debug.acpi.layer="ACPI_ALL_COMPONENTS ACPI_ALL_DRIVERS"
 debug.acpi.level="ACPI_LV_ERROR"

   If the required information is triggered by a specific event, such as a
   suspend and then resume, do not modify /boot/loader.conf. Instead, use
   sysctl to specify the layer and level after booting and preparing the
   system for the specific event. The variables which can be set using sysctl
   are named the same as the tunables in /boot/loader.conf.

   Once the debugging information is gathered, it can be sent to freebsd-acpi
   so that it can be used by the FreeBSD ACPI maintainers to identify the
   root cause of the problem and to develop a solution.

  Note:

   Before submitting debugging information to this mailing list, ensure the
   latest BIOS version is installed and, if available, the embedded
   controller firmware version.

   When submitting a problem report, include the following information:

     * Description of the buggy behavior, including system type, model, and
       anything that causes the bug to appear. Note as accurately as possible
       when the bug began occurring if it is new.

     * The output of dmesg after running boot -v, including any error
       messages generated by the bug.

     * The dmesg output from boot -v with ACPI disabled, if disabling ACPI
       helps to fix the problem.

     * Output from sysctl hw.acpi. This lists which features the system
       offers.

     * The URL to a pasted version of the system's ASL. Do not send the ASL
       directly to the list as it can be very large. Generate a copy of the
       ASL by running this command:

 # acpidump -dt > name-system.asl

       Substitute the login name for name and manufacturer/model for system.
       For example, use njl-FooCo6000.asl.

   Most FreeBSD developers watch the FreeBSD-CURRENT mailing list, but one
   should submit problems to freebsd-acpi to be sure it is seen. Be patient
   when waiting for a response. If the bug is not immediately apparent,
   submit a bug report. When entering a PR, include the same information as
   requested above. This helps developers to track the problem and resolve
   it. Do not send a PR without emailing freebsd-acpi first as it is likely
   that the problem has been reported before.

  12.13.5. References

   More information about ACPI may be found in the following locations:

     * The FreeBSD ACPI Mailing List Archives
       (https://lists.freebsd.org/pipermail/freebsd-acpi/)

     * The ACPI 2.0 Specification (http://acpi.info/spec.htm)

     * acpi(4), acpi_thermal(4), acpidump(8), iasl(8), and acpidb(8)

     ----------------------------------------------------------------------

   [2] The auto-tuning algorithm sets maxusers equal to the amount of memory
   in the system, with a minimum of 32, and a maximum of 384.

Chapter 13. The FreeBSD Booting Process

   Table of Contents

   13.1. Synopsis

   13.2. FreeBSD Boot Process

   13.3. Configuring Boot Time Splash Screens

   13.4. Device Hints

   13.5. Shutdown Sequence

13.1. Synopsis

   The process of starting a computer and loading the operating system is
   referred to as "the bootstrap process", or "booting". FreeBSD's boot
   process provides a great deal of flexibility in customizing what happens
   when the system starts, including the ability to select from different
   operating systems installed on the same computer, different versions of
   the same operating system, or a different installed kernel.

   This chapter details the configuration options that can be set. It
   demonstrates how to customize the FreeBSD boot process, including
   everything that happens until the FreeBSD kernel has started, probed for
   devices, and started init(8). This occurs when the text color of the boot
   messages changes from bright white to grey.

   After reading this chapter, you will recognize:

     * The components of the FreeBSD bootstrap system and how they interact.

     * The options that can be passed to the components in the FreeBSD
       bootstrap in order to control the boot process.

     * How to configure a customized boot splash screen.

     * The basics of setting device hints.

     * How to boot into single- and multi-user mode and how to properly shut
       down a FreeBSD system.

  Note:

   This chapter only describes the boot process for FreeBSD running on x86
   and amd64 systems.

13.2. FreeBSD Boot Process

   Turning on a computer and starting the operating system poses an
   interesting dilemma. By definition, the computer does not know how to do
   anything until the operating system is started. This includes running
   programs from the disk. If the computer can not run a program from the
   disk without the operating system, and the operating system programs are
   on the disk, how is the operating system started?

   This problem parallels one in the book The Adventures of Baron Munchausen.
   A character had fallen part way down a manhole, and pulled himself out by
   grabbing his bootstraps and lifting. In the early days of computing, the
   term bootstrap was applied to the mechanism used to load the operating
   system. It has since become shortened to "booting".

   On x86 hardware, the Basic Input/Output System (BIOS) is responsible for
   loading the operating system. The BIOS looks on the hard disk for the
   Master Boot Record (MBR), which must be located in a specific place on the
   disk. The BIOS has enough knowledge to load and run the MBR, and assumes
   that the MBR can then carry out the rest of the tasks involved in loading
   the operating system, possibly with the help of the BIOS.

  Note:

   FreeBSD provides for booting from both the older MBR standard, and the
   newer GUID Partition Table (GPT). GPT partitioning is often found on
   computers with the Unified Extensible Firmware Interface (UEFI). However,
   FreeBSD can boot from GPT partitions even on machines with only a legacy
   BIOS with gptboot(8). Work is under way to provide direct UEFI booting.

   The code within the MBR is typically referred to as a boot manager,
   especially when it interacts with the user. The boot manager usually has
   more code in the first track of the disk or within the file system.
   Examples of boot managers include the standard FreeBSD boot manager boot0,
   also called Boot Easy, and Grub, which is used by many Linux(R)
   distributions.

   If only one operating system is installed, the MBR searches for the first
   bootable (active) slice on the disk, and then runs the code on that slice
   to load the remainder of the operating system. When multiple operating
   systems are present, a different boot manager can be installed to display
   a list of operating systems so the user can select one to boot.

   The remainder of the FreeBSD bootstrap system is divided into three
   stages. The first stage knows just enough to get the computer into a
   specific state and run the second stage. The second stage can do a little
   bit more, before running the third stage. The third stage finishes the
   task of loading the operating system. The work is split into three stages
   because the MBR puts limits on the size of the programs that can be run at
   stages one and two. Chaining the tasks together allows FreeBSD to provide
   a more flexible loader.

   The kernel is then started and begins to probe for devices and initialize
   them for use. Once the kernel boot process is finished, the kernel passes
   control to the user process init(8), which makes sure the disks are in a
   usable state, starts the user-level resource configuration which mounts
   file systems, sets up network cards to communicate on the network, and
   starts the processes which have been configured to run at startup.

   This section describes these stages in more detail and demonstrates how to
   interact with the FreeBSD boot process.

  13.2.1. The Boot Manager

   The boot manager code in the MBR is sometimes referred to as stage zero of
   the boot process. By default, FreeBSD uses the boot0 boot manager.

   The MBR installed by the FreeBSD installer is based on /boot/boot0. The
   size and capability of boot0 is restricted to 446 bytes due to the slice
   table and 0x55AA identifier at the end of the MBR. If boot0 and multiple
   operating systems are installed, a message similar to this example will be
   displayed at boot time:

   Example 13.1. boot0 Screenshot

 F1 Win
 F2 FreeBSD

 Default: F2

   Other operating systems will overwrite an existing MBR if they are
   installed after FreeBSD. If this happens, or to replace the existing MBR
   with the FreeBSD MBR, use the following command:

 # fdisk -B -b /boot/boot0 device

   where device is the boot disk, such as ad0 for the first IDE disk, ad2 for
   the first IDE disk on a second IDE controller, or da0 for the first SCSI
   disk. To create a custom configuration of the MBR, refer to boot0cfg(8).

  13.2.2. Stage One and Stage Two

   Conceptually, the first and second stages are part of the same program on
   the same area of the disk. Due to space constraints, they have been split
   into two, but are always installed together. They are copied from the
   combined /boot/boot by the FreeBSD installer or bsdlabel.

   These two stages are located outside file systems, in the first track of
   the boot slice, starting with the first sector. This is where boot0, or
   any other boot manager, expects to find a program to run which will
   continue the boot process.

   The first stage, boot1, is very simple, since it can only be 512 bytes in
   size. It knows just enough about the FreeBSD bsdlabel, which stores
   information about the slice, to find and execute boot2.

   Stage two, boot2, is slightly more sophisticated, and understands the
   FreeBSD file system enough to find files. It can provide a simple
   interface to choose the kernel or loader to run. It runs loader, which is
   much more sophisticated and provides a boot configuration file. If the
   boot process is interrupted at stage two, the following interactive screen
   is displayed:

   Example 13.2. boot2 Screenshot

 >> FreeBSD/i386 BOOT
 Default: 0:ad(0,a)/boot/loader
 boot:

   To replace the installed boot1 and boot2, use bsdlabel, where diskslice is
   the disk and slice to boot from, such as ad0s1 for the first slice on the
   first IDE disk:

 # bsdlabel -B diskslice

  Warning:

   If just the disk name is used, such as ad0, bsdlabel will create the disk
   in "dangerously dedicated mode", without slices. This is probably not the
   desired action, so double check the diskslice before pressing Return.

  13.2.3. Stage Three

   The loader is the final stage of the three-stage bootstrap process. It is
   located on the file system, usually as /boot/loader.

   The loader is intended as an interactive method for configuration, using a
   built-in command set, backed up by a more powerful interpreter which has a
   more complex command set.

   During initialization, loader will probe for a console and for disks, and
   figure out which disk it is booting from. It will set variables
   accordingly, and an interpreter is started where user commands can be
   passed from a script or interactively.

   The loader will then read /boot/loader.rc, which by default reads in
   /boot/defaults/loader.conf which sets reasonable defaults for variables
   and reads /boot/loader.conf for local changes to those variables.
   loader.rc then acts on these variables, loading whichever modules and
   kernel are selected.

   Finally, by default, loader issues a 10 second wait for key presses, and
   boots the kernel if it is not interrupted. If interrupted, the user is
   presented with a prompt which understands the command set, where the user
   may adjust variables, unload all modules, load modules, and then finally
   boot or reboot. Table 13.1, "Loader Built-In Commands" lists the most
   commonly used loader commands. For a complete discussion of all available
   commands, refer to loader(8).

   Table 13.1. Loader Built-In Commands

          Variable                            Description                     
                           Proceeds to boot the kernel if not interrupted     
   autoboot seconds        within the time span given, in seconds. It         
                           displays a countdown, and the default time span is 
                           10 seconds.                                        
                           Immediately proceeds to boot the kernel, with any  
                           specified options or kernel name. Providing a      
   boot [-options]         kernel name on the command-line is only applicable 
   [kernelname]            after an unload has been issued. Otherwise, the    
                           previously-loaded kernel will be used. If          
                           kernelname is not qualified, it will be searched   
                           under /boot/kernel and /boot/modules.              
                           Goes through the same automatic configuration of   
   boot-conf               modules based on specified variables, most         
                           commonly kernel. This only makes sense if unload   
                           is used first, before changing some variables.     
                           Shows help messages read from /boot/loader.help.   
   help [topic]            If the topic given is index, the list of available 
                           topics is displayed.                               
   include filename ...    Reads the specified file and interprets it line by 
                           line. An error immediately stops the include.      
                           Loads the kernel, kernel module, or file of the    
                           type given, with the specified filename. Any       
   load [-t type] filename arguments after filename are passed to the file.   
                           If filename is not qualified, it will be searched  
                           under /boot/kernel and /boot/modules.              
                           Displays a listing of files in the given path, or  
   ls [-l] [path]          the root directory, if the path is not specified.  
                           If -l is specified, file sizes will also be shown. 
                           Lists all of the devices from which it may be      
   lsdev [-v]              possible to load modules. If -v is specified, more 
                           details are printed.                               
   lsmod [-v]              Displays loaded modules. If -v is specified, more  
                           details are shown.                                 
   more filename           Displays the files specified, with a pause at each 
                           LINES displayed.                                   
   reboot                  Immediately reboots the system.                    
   set variable, set       Sets the specified environment variables.          
   variable=value          
   unload                  Removes all loaded modules.                        

   Here are some practical examples of loader usage. To boot the usual kernel
   in single-user mode :

 boot -s

   To unload the usual kernel and modules and then load the previous or
   another, specified kernel:

 unload
 load /path/to/kernelfile

   Use the qualified /boot/GENERIC/kernel to refer to the default kernel that
   comes with an installation, or /boot/kernel.old/kernel, to refer to the
   previously installed kernel before a system upgrade or before configuring
   a custom kernel.

   Use the following to load the usual modules with another kernel. Note that
   in this case it is not necessary the qualified name:

 unload
 set kernel="mykernel"
 boot-conf

   To load an automated kernel configuration script:

 load -t userconfig_script /boot/kernel.conf

  13.2.4. Last Stage

   Once the kernel is loaded by either loader or by boot2, which bypasses
   loader, it examines any boot flags and adjusts its behavior as necessary.
   Table 13.2, "Kernel Interaction During Boot" lists the commonly used boot
   flags. Refer to boot(8) for more information on the other boot flags.

   Table 13.2. Kernel Interaction During Boot

   Option                             Description                             
   -a     During kernel initialization, ask for the device to mount as the    
          root file system.                                                   
   -C     Boot the root file system from a CDROM.                             
   -s     Boot into single-user mode.                                         
   -v     Be more verbose during kernel startup.                              

   Once the kernel has finished booting, it passes control to the user
   process init(8), which is located at /sbin/init, or the program path
   specified in the init_path variable in loader. This is the last stage of
   the boot process.

   The boot sequence makes sure that the file systems available on the system
   are consistent. If a UFS file system is not, and fsck cannot fix the
   inconsistencies, init drops the system into single-user mode so that the
   system administrator can resolve the problem directly. Otherwise, the
   system boots into multi-user mode.

    13.2.4.1. Single-User Mode

   A user can specify this mode by booting with -s or by setting the
   boot_single variable in loader. It can also be reached by running shutdown
   now from multi-user mode. Single-user mode begins with this message:

 Enter full pathname of shell or RETURN for /bin/sh:

   If the user presses Enter, the system will enter the default Bourne shell.
   To specify a different shell, input the full path to the shell.

   Single-user mode is usually used to repair a system that will not boot due
   to an inconsistent file system or an error in a boot configuration file.
   It can also be used to reset the root password when it is unknown. These
   actions are possible as the single-user mode prompt gives full, local
   access to the system and its configuration files. There is no networking
   in this mode.

   While single-user mode is useful for repairing a system, it poses a
   security risk unless the system is in a physically secure location. By
   default, any user who can gain physical access to a system will have full
   control of that system after booting into single-user mode.

   If the system console is changed to insecure in /etc/ttys, the system will
   first prompt for the root password before initiating single-user mode.
   This adds a measure of security while removing the ability to reset the
   root password when it is unknown.

   Example 13.3. Configuring an Insecure Console in /etc/ttys

 # name  getty                           type    status          comments
 #
 # If console is marked "insecure", then init will ask for the root password
 # when going to single-user mode.
 console none                            unknown off insecure

   An insecure console means that physical security to the console is
   considered to be insecure, so only someone who knows the root password may
   use single-user mode.

    13.2.4.2. Multi-User Mode

   If init finds the file systems to be in order, or once the user has
   finished their commands in single-user mode and has typed exit to leave
   single-user mode, the system enters multi-user mode, in which it starts
   the resource configuration of the system.

   The resource configuration system reads in configuration defaults from
   /etc/defaults/rc.conf and system-specific details from /etc/rc.conf. It
   then proceeds to mount the system file systems listed in /etc/fstab. It
   starts up networking services, miscellaneous system daemons, then the
   startup scripts of locally installed packages.

   To learn more about the resource configuration system, refer to rc(8) and
   examine the scripts located in /etc/rc.d.

13.3. Configuring Boot Time Splash Screens

   Contributed by Joseph J. Barbish.

   Typically when a FreeBSD system boots, it displays its progress as a
   series of messages at the console. A boot splash screen creates an
   alternate boot screen that hides all of the boot probe and service startup
   messages. A few boot loader messages, including the boot options menu and
   a timed wait countdown prompt, are displayed at boot time, even when the
   splash screen is enabled. The display of the splash screen can be turned
   off by hitting any key on the keyboard during the boot process.

   There are two basic environments available in FreeBSD. The first is the
   default legacy virtual console command line environment. After the system
   finishes booting, a console login prompt is presented. The second
   environment is a configured graphical environment. Refer to Chapter 5, The
   X Window System for more information on how to install and configure a
   graphical display manager and a graphical login manager.

   Once the system has booted, the splash screen defaults to being a screen
   saver. After a time period of non-use, the splash screen will display and
   will cycle through steps of changing intensity of the image, from bright
   to very dark and over again. The configuration of the splash screen saver
   can be overridden by adding a saver= line to /etc/rc.conf. Several
   built-in screen savers are available and described in splash(4). The
   saver= option only applies to virtual consoles and has no effect on
   graphical display managers.

   By installing the sysutils/bsd-splash-changer package or port, a random
   splash image from a collection will display at boot. The splash screen
   function supports 256-colors in the bitmap (.bmp), ZSoft PCX (.pcx), or
   TheDraw (.bin) formats. The .bmp, .pcx, or .bin image has to be placed on
   the root partition, for example in /boot. The splash image files must have
   a resolution of 320 by 200 pixels or less in order to work on standard VGA
   adapters. For the default boot display resolution of 256-colors and 320 by
   200 pixels or less, add the following lines to /boot/loader.conf. Replace
   splash.bmp with the name of the bitmap file to use:

 splash_bmp_load="YES"
 bitmap_load="YES"
 bitmap_name="/boot/splash.bmp"

   To use a PCX file instead of a bitmap file:

 splash_pcx_load="YES"
 bitmap_load="YES"
 bitmap_name="/boot/splash.pcx"

   To instead use ASCII art in the https://en.wikipedia.org/wiki/TheDraw
   format:

 splash_txt="YES"
 bitmap_load="YES"
 bitmap_name="/boot/splash.bin"

   Other interesting loader.conf options include:

   beastie_disable="YES"

           This will stop the boot options menu from being displayed, but the
           timed wait count down prompt will still be present. Even with the
           display of the boot options menu disabled, entering an option
           selection at the timed wait count down prompt will enact the
           corresponding boot option.

   loader_logo="beastie"

           This will replace the default words "FreeBSD", which are displayed
           to the right of the boot options menu, with the colored beastie
           logo.

   For more information, refer to splash(4), loader.conf(5), and vga(4).

13.4. Device Hints

   Contributed by Tom Rhodes.

   During initial system startup, the boot loader(8) reads device.hints(5).
   This file stores kernel boot information known as variables, sometimes
   referred to as "device hints". These "device hints" are used by device
   drivers for device configuration.

   Device hints may also be specified at the Stage 3 boot loader prompt, as
   demonstrated in Section 13.2.3, "Stage Three". Variables can be added
   using set, removed with unset, and viewed show. Variables set in
   /boot/device.hints can also be overridden. Device hints entered at the
   boot loader are not permanent and will not be applied on the next reboot.

   Once the system is booted, kenv(1) can be used to dump all of the
   variables.

   The syntax for /boot/device.hints is one variable per line, using the hash
   "#" as comment markers. Lines are constructed as follows:

 hint.driver.unit.keyword="value"

   The syntax for the Stage 3 boot loader is:

 set hint.driver.unit.keyword=value

   where driver is the device driver name, unit is the device driver unit
   number, and keyword is the hint keyword. The keyword may consist of the
   following options:

     * at: specifies the bus which the device is attached to.

     * port: specifies the start address of the I/O to be used.

     * irq: specifies the interrupt request number to be used.

     * drq: specifies the DMA channel number.

     * maddr: specifies the physical memory address occupied by the device.

     * flags: sets various flag bits for the device.

     * disabled: if set to 1 the device is disabled.

   Since device drivers may accept or require more hints not listed here,
   viewing a driver's manual page is recommended. For more information, refer
   to device.hints(5), kenv(1), loader.conf(5), and loader(8).

13.5. Shutdown Sequence

   Upon controlled shutdown using shutdown(8), init(8) will attempt to run
   the script /etc/rc.shutdown, and then proceed to send all processes the
   TERM signal, and subsequently the KILL signal to any that do not terminate
   in a timely manner.

   To power down a FreeBSD machine on architectures and systems that support
   power management, use shutdown -p now to turn the power off immediately.
   To reboot a FreeBSD system, use shutdown -r now. One must be root or a
   member of operator in order to run shutdown(8). One can also use halt(8)
   and reboot(8). Refer to their manual pages and to shutdown(8) for more
   information.

   Modify group membership by referring to Section 3.3, "Users and Basic
   Account Management".

  Note:

   Power management requires acpi(4) to be loaded as a module or statically
   compiled into a custom kernel.

Chapter 14. Security

   Rewritten by Tom Rhodes.
   Table of Contents

   14.1. Synopsis

   14.2. Introduction

   14.3. One-time Passwords

   14.4. TCP Wrapper

   14.5. Kerberos

   14.6. OpenSSL

   14.7. VPN over IPsec

   14.8. OpenSSH

   14.9. Access Control Lists

   14.10. Monitoring Third Party Security Issues

   14.11. FreeBSD Security Advisories

   14.12. Process Accounting

   14.13. Resource Limits

   14.14. Shared Administration with Sudo

14.1. Synopsis

   Security, whether physical or virtual, is a topic so broad that an entire
   industry has evolved around it. Hundreds of standard practices have been
   authored about how to secure systems and networks, and as a user of
   FreeBSD, understanding how to protect against attacks and intruders is a
   must.

   In this chapter, several fundamentals and techniques will be discussed.
   The FreeBSD system comes with multiple layers of security, and many more
   third party utilities may be added to enhance security.

   After reading this chapter, you will know:

     * Basic FreeBSD system security concepts.

     * The various crypt mechanisms available in FreeBSD.

     * How to set up one-time password authentication.

     * How to configure TCP Wrapper for use with inetd(8).

     * How to set up Kerberos on FreeBSD.

     * How to configure IPsec and create a VPN.

     * How to configure and use OpenSSH on FreeBSD.

     * How to use file system ACLs.

     * How to use pkg to audit third party software packages installed from
       the Ports Collection.

     * How to utilize FreeBSD security advisories.

     * What Process Accounting is and how to enable it on FreeBSD.

     * How to control user resources using login classes or the resource
       limits database.

   Before reading this chapter, you should:

     * Understand basic FreeBSD and Internet concepts.

   Additional security topics are covered elsewhere in this Handbook. For
   example, Mandatory Access Control is discussed in Chapter 16, Mandatory
   Access Control and Internet firewalls are discussed in Chapter 31,
   Firewalls.

14.2. Introduction

   Security is everyone's responsibility. A weak entry point in any system
   could allow intruders to gain access to critical information and cause
   havoc on an entire network. One of the core principles of information
   security is the CIA triad, which stands for the Confidentiality,
   Integrity, and Availability of information systems.

   The CIA triad is a bedrock concept of computer security as customers and
   users expect their data to be protected. For example, a customer expects
   that their credit card information is securely stored (confidentiality),
   that their orders are not changed behind the scenes (integrity), and that
   they have access to their order information at all times (availablility).

   To provide CIA, security professionals apply a defense in depth strategy.
   The idea of defense in depth is to add several layers of security to
   prevent one single layer failing and the entire security system
   collapsing. For example, a system administrator cannot simply turn on a
   firewall and consider the network or system secure. One must also audit
   accounts, check the integrity of binaries, and ensure malicious tools are
   not installed. To implement an effective security strategy, one must
   understand threats and how to defend against them.

   What is a threat as it pertains to computer security? Threats are not
   limited to remote attackers who attempt to access a system without
   permission from a remote location. Threats also include employees,
   malicious software, unauthorized network devices, natural disasters,
   security vulnerabilities, and even competing corporations.

   Systems and networks can be accessed without permission, sometimes by
   accident, or by remote attackers, and in some cases, via corporate
   espionage or former employees. As a user, it is important to prepare for
   and admit when a mistake has led to a security breach and report possible
   issues to the security team. As an administrator, it is important to know
   of the threats and be prepared to mitigate them.

   When applying security to systems, it is recommended to start by securing
   the basic accounts and system configuration, and then to secure the
   network layer so that it adheres to the system policy and the
   organization's security procedures. Many organizations already have a
   security policy that covers the configuration of technology devices. The
   policy should include the security configuration of workstations,
   desktops, mobile devices, phones, production servers, and development
   servers. In many cases, standard operating procedures (SOPs) already
   exist. When in doubt, ask the security team.

   The rest of this introduction describes how some of these basic security
   configurations are performed on a FreeBSD system. The rest of this chapter
   describes some specific tools which can be used when implementing a
   security policy on a FreeBSD system.

  14.2.1. Preventing Logins

   In securing a system, a good starting point is an audit of accounts.
   Ensure that root has a strong password and that this password is not
   shared. Disable any accounts that do not need login access.

   To deny login access to accounts, two methods exist. The first is to lock
   the account. This example locks the toor account:

 # pw lock toor

   The second method is to prevent login access by changing the shell to
   /usr/sbin/nologin. Only the superuser can change the shell for other
   users:

 # chsh -s /usr/sbin/nologin toor

   The /usr/sbin/nologin shell prevents the system from assigning a shell to
   the user when they attempt to login.

  14.2.2. Permitted Account Escalation

   In some cases, system administration needs to be shared with other users.
   FreeBSD has two methods to handle this. The first one, which is not
   recommended, is a shared root password used by members of the wheel group.
   With this method, a user types su and enters the password for wheel
   whenever superuser access is needed. The user should then type exit to
   leave privileged access after finishing the commands that required
   administrative access. To add a user to this group, edit /etc/group and
   add the user to the end of the wheel entry. The user must be separated by
   a comma character with no space.

   The second, and recommended, method to permit privilege escalation is to
   install the security/sudo package or port. This software provides
   additional auditing, more fine-grained user control, and can be configured
   to lock users into running only the specified privileged commands.

   After installation, use visudo to edit /usr/local/etc/sudoers. This
   example creates a new webadmin group, adds the trhodes account to that
   group, and configures that group access to restart apache24:

 # pw groupadd webadmin -M trhodes -g 6000
 # visudo
 %webadmin ALL=(ALL) /usr/sbin/service apache24 *

  14.2.3. Password Hashes

   Passwords are a necessary evil of technology. When they must be used, they
   should be complex and a powerful hash mechanism should be used to encrypt
   the version that is stored in the password database. FreeBSD supports the
   DES, MD5, SHA256, SHA512, and Blowfish hash algorithms in its crypt()
   library. The default of SHA512 should not be changed to a less secure
   hashing algorithm, but can be changed to the more secure Blowfish
   algorithm.

  Note:

   Blowfish is not part of AES and is not considered compliant with any
   Federal Information Processing Standards (FIPS). Its use may not be
   permitted in some environments.

   To determine which hash algorithm is used to encrypt a user's password,
   the superuser can view the hash for the user in the FreeBSD password
   database. Each hash starts with a symbol which indicates the type of hash
   mechanism used to encrypt the password. If DES is used, there is no
   beginning symbol. For MD5, the symbol is $. For SHA256 and SHA512, the
   symbol is $6$. For Blowfish, the symbol is $2a$. In this example, the
   password for dru is hashed using the default SHA512 algorithm as the hash
   starts with $6$. Note that the encrypted hash, not the password itself, is
   stored in the password database:

 # grep dru /etc/master.passwd
 dru:$6$pzIjSvCAn.PBYQBA$PXpSeWPx3g5kscj3IMiM7tUEUSPmGexxta.8Lt9TGSi2lNQqYGKszsBPuGME0:1001:1001::0:0:dru:/usr/home/dru:/bin/csh

   The hash mechanism is set in the user's login class. For this example, the
   user is in the default login class and the hash algorithm is set with this
   line in /etc/login.conf:

         :passwd_format=sha512:\

   To change the algorithm to Blowfish, modify that line to look like this:

         :passwd_format=blf:\

   Then run cap_mkdb /etc/login.conf as described in Section 14.13.1,
   "Configuring Login Classes". Note that this change will not affect any
   existing password hashes. This means that all passwords should be
   re-hashed by asking users to run passwd in order to change their password.

   For remote logins, two-factor authentication should be used. An example of
   two-factor authentication is "something you have", such as a key, and
   "something you know", such as the passphrase for that key. Since OpenSSH
   is part of the FreeBSD base system, all network logins should be over an
   encrypted connection and use key-based authentication instead of
   passwords. For more information, refer to Section 14.8, "OpenSSH".
   Kerberos users may need to make additional changes to implement OpenSSH in
   their network. These changes are described in Section 14.5, "Kerberos".

  14.2.4. Password Policy Enforcement

   Enforcing a strong password policy for local accounts is a fundamental
   aspect of system security. In FreeBSD, password length, password strength,
   and password complexity can be implemented using built-in Pluggable
   Authentication Modules (PAM).

   This section demonstrates how to configure the minimum and maximum
   password length and the enforcement of mixed characters using the
   pam_passwdqc.so module. This module is enforced when a user changes their
   password.

   To configure this module, become the superuser and uncomment the line
   containing pam_passwdqc.so in /etc/pam.d/passwd. Then, edit that line to
   match the password policy:

 password        requisite       pam_passwdqc.so         min=disabled,disabled,disabled,12,10 similar=deny retry=3 enforce=users

   This example sets several requirements for new passwords. The min setting
   controls the minimum password length. It has five values because this
   module defines five different types of passwords based on their
   complexity. Complexity is defined by the type of characters that must
   exist in a password, such as letters, numbers, symbols, and case. The
   types of passwords are described in pam_passwdqc(8). In this example, the
   first three types of passwords are disabled, meaning that passwords that
   meet those complexity requirements will not be accepted, regardless of
   their length. The 12 sets a minimum password policy of at least twelve
   characters, if the password also contains characters with three types of
   complexity. The 10 sets the password policy to also allow passwords of at
   least ten characters, if the password contains characters with four types
   of complexity.

   The similar setting denies passwords that are similar to the user's
   previous password. The retry setting provides a user with three
   opportunities to enter a new password.

   Once this file is saved, a user changing their password will see a message
   similar to the following:

 % passwd
 Changing local password for trhodes
 Old Password:

 You can now choose the new password.
 A valid password should be a mix of upper and lower case letters,
 digits and other characters.  You can use a 12 character long
 password with characters from at least 3 of these 4 classes, or
 a 10 character long password containing characters from all the
 classes.  Characters that form a common pattern are discarded by
 the check.
 Alternatively, if no one else can see your terminal now, you can
 pick this as your password: "trait-useful&knob".
 Enter new password:

   If a password that does not match the policy is entered, it will be
   rejected with a warning and the user will have an opportunity to try
   again, up to the configured number of retries.

   Most password policies require passwords to expire after so many days. To
   set a password age time in FreeBSD, set passwordtime for the user's login
   class in /etc/login.conf. The default login class contains an example:

 #       :passwordtime=90d:\

   So, to set an expiry of 90 days for this login class, remove the comment
   symbol (#), save the edit, and run cap_mkdb /etc/login.conf.

   To set the expiration on individual users, pass an expiration date or the
   number of days to expiry and a username to pw:

 # pw usermod -p 30-apr-2015 -n trhodes

   As seen here, an expiration date is set in the form of day, month, and
   year. For more information, see pw(8).

  14.2.5. Detecting Rootkits

   A rootkit is any unauthorized software that attempts to gain root access
   to a system. Once installed, this malicious software will normally open up
   another avenue of entry for an attacker. Realistically, once a system has
   been compromised by a rootkit and an investigation has been performed, the
   system should be reinstalled from scratch. There is tremendous risk that
   even the most prudent security or systems engineer will miss something an
   attacker left behind.

   A rootkit does do one thing useful for administrators: once detected, it
   is a sign that a compromise happened at some point. But, these types of
   applications tend to be very well hidden. This section demonstrates a tool
   that can be used to detect rootkits, security/rkhunter.

   After installation of this package or port, the system may be checked
   using the following command. It will produce a lot of information and will
   require some manual pressing of ENTER:

 # rkhunter -c

   After the process completes, a status message will be printed to the
   screen. This message will include the amount of files checked, suspect
   files, possible rootkits, and more. During the check, some generic
   security warnings may be produced about hidden files, the OpenSSH protocol
   selection, and known vulnerable versions of installed software. These can
   be handled now or after a more detailed analysis has been performed.

   Every administrator should know what is running on the systems they are
   responsible for. Third-party tools like rkhunter and sysutils/lsof, and
   native commands such as netstat and ps, can show a great deal of
   information on the system. Take notes on what is normal, ask questions
   when something seems out of place, and be paranoid. While preventing a
   compromise is ideal, detecting a compromise is a must.

  14.2.6. Binary Verification

   Verification of system files and binaries is important because it provides
   the system administration and security teams information about system
   changes. A software application that monitors the system for changes is
   called an Intrusion Detection System (IDS).

   FreeBSD provides native support for a basic IDS system. While the nightly
   security emails will notify an administrator of changes, the information
   is stored locally and there is a chance that a malicious user could modify
   this information in order to hide their changes to the system. As such, it
   is recommended to create a separate set of binary signatures and store
   them on a read-only, root-owned directory or, preferably, on a removable
   USB disk or remote rsync server.

   The built-in mtree utility can be used to generate a specification of the
   contents of a directory. A seed, or a numeric constant, is used to
   generate the specification and is required to check that the specification
   has not changed. This makes it possible to determine if a file or binary
   has been modified. Since the seed value is unknown by an attacker, faking
   or checking the checksum values of files will be difficult to impossible.
   The following example generates a set of SHA256 hashes, one for each
   system binary in /bin, and saves those values to a hidden file in root's
   home directory, /root/.bin_chksum_mtree:

 # mtree -s 3483151339707503 -c -K cksum,sha256digest -p /bin > /root/.bin_chksum_mtree
 # mtree: /bin checksum: 3427012225

   The 3483151339707503 represents the seed. This value should be remembered,
   but not shared.

   Viewing /root/.bin_cksum_mtree should yield output similar to the
   following:

 #          user: root
 #       machine: dreadnaught
 #          tree: /bin
 #          date: Mon Feb  3 10:19:53 2014

 # .
 /set type=file uid=0 gid=0 mode=0555 nlink=1 flags=none
 .               type=dir mode=0755 nlink=2 size=1024 \
                 time=1380277977.000000000
     \133        nlink=2 size=11704 time=1380277977.000000000 \
                 cksum=484492447 \
                 sha256digest=6207490fbdb5ed1904441fbfa941279055c3e24d3a4049aeb45094596400662a
     cat         size=12096 time=1380277975.000000000 cksum=3909216944 \
                 sha256digest=65ea347b9418760b247ab10244f47a7ca2a569c9836d77f074e7a306900c1e69
     chflags     size=8168 time=1380277975.000000000 cksum=3949425175 \
                 sha256digest=c99eb6fc1c92cac335c08be004a0a5b4c24a0c0ef3712017b12c89a978b2dac3
     chio        size=18520 time=1380277975.000000000 cksum=2208263309 \
                 sha256digest=ddf7c8cb92a58750a675328345560d8cc7fe14fb3ccd3690c34954cbe69fc964
     chmod       size=8640 time=1380277975.000000000 cksum=2214429708 \
                 sha256digest=a435972263bf814ad8df082c0752aa2a7bdd8b74ff01431ccbd52ed1e490bbe7

   The machine's hostname, the date and time the specification was created,
   and the name of the user who created the specification are included in
   this report. There is a checksum, size, time, and SHA256 digest for each
   binary in the directory.

   To verify that the binary signatures have not changed, compare the current
   contents of the directory to the previously generated specification, and
   save the results to a file. This command requires the seed that was used
   to generate the original specification:

 # mtree -s 3483151339707503 -p /bin < /root/.bin_chksum_mtree >> /root/.bin_chksum_output
 # mtree: /bin checksum: 3427012225

   This should produce the same checksum for /bin that was produced when the
   specification was created. If no changes have occurred to the binaries in
   this directory, the /root/.bin_chksum_output output file will be empty. To
   simulate a change, change the date on /bin/cat using touch and run the
   verification command again:

 # touch /bin/cat
 # mtree -s 3483151339707503 -p /bin < /root/.bin_chksum_mtree >> /root/.bin_chksum_output
 # more /root/.bin_chksum_output
 cat changed
         modification time expected Fri Sep 27 06:32:55 2013 found Mon Feb  3 10:28:43 2014

   It is recommended to create specifications for the directories which
   contain binaries and configuration files, as well as any directories
   containing sensitive data. Typically, specifications are created for /bin,
   /sbin, /usr/bin, /usr/sbin, /usr/local/bin, /etc, and /usr/local/etc.

   More advanced IDS systems exist, such as security/aide. In most cases,
   mtree provides the functionality administrators need. It is important to
   keep the seed value and the checksum output hidden from malicious users.
   More information about mtree can be found in mtree(8).

  14.2.7. System Tuning for Security

   In FreeBSD, many system features can be tuned using sysctl. A few of the
   security features which can be tuned to prevent Denial of Service (DoS)
   attacks will be covered in this section. More information about using
   sysctl, including how to temporarily change values and how to make the
   changes permanent after testing, can be found in Section 12.9, "Tuning
   with sysctl(8)".

  Note:

   Any time a setting is changed with sysctl, the chance to cause undesired
   harm is increased, affecting the availability of the system. All changes
   should be monitored and, if possible, tried on a testing system before
   being used on a production system.

   By default, the FreeBSD kernel boots with a security level of -1. This is
   called "insecure mode" because immutable file flags may be turned off and
   all devices may be read from or written to. The security level will remain
   at -1 unless it is altered through sysctl or by a setting in the startup
   scripts. The security level may be increased during system startup by
   setting kern_securelevel_enable to YES in /etc/rc.conf, and the value of
   kern_securelevel to the desired security level. See security(7) and
   init(8) for more information on these settings and the available security
   levels.

  Warning:

   Increasing the securelevel can break Xorg and cause other issues. Be
   prepared to do some debugging.

   The net.inet.tcp.blackhole and net.inet.udp.blackhole settings can be used
   to drop incoming SYN packets on closed ports without sending a return RST
   response. The default behavior is to return an RST to show a port is
   closed. Changing the default provides some level of protection against
   ports scans, which are used to determine which applications are running on
   a system. Set net.inet.tcp.blackhole to 2 and net.inet.udp.blackhole to 1.
   Refer to blackhole(4) for more information about these settings.

   The net.inet.icmp.drop_redirect and net.inet.ip.redirect settings help
   prevent against redirect attacks. A redirect attack is a type of DoS which
   sends mass numbers of ICMP type 5 packets. Since these packets are not
   required, set net.inet.icmp.drop_redirect to 1 and set
   net.inet.ip.redirect to 0.

   Source routing is a method for detecting and accessing non-routable
   addresses on the internal network. This should be disabled as non-routable
   addresses are normally not routable on purpose. To disable this feature,
   set net.inet.ip.sourceroute and net.inet.ip.accept_sourceroute to 0.

   When a machine on the network needs to send messages to all hosts on a
   subnet, an ICMP echo request message is sent to the broadcast address.
   However, there is no reason for an external host to perform such an
   action. To reject all external broadcast requests, set
   net.inet.icmp.bmcastecho to 0.

   Some additional settings are documented in security(7).

14.3. One-time Passwords

   By default, FreeBSD includes support for One-time Passwords In Everything
   (OPIE). OPIE is designed to prevent replay attacks, in which an attacker
   discovers a user's password and uses it to access a system. Since a
   password is only used once in OPIE, a discovered password is of little use
   to an attacker. OPIE uses a secure hash and a challenge/response system to
   manage passwords. The FreeBSD implementation uses the MD5 hash by default.

   OPIE uses three different types of passwords. The first is the usual
   UNIX(R) or Kerberos password. The second is the one-time password which is
   generated by opiekey. The third type of password is the "secret password"
   which is used to generate one-time passwords. The secret password has
   nothing to do with, and should be different from, the UNIX(R) password.

   There are two other pieces of data that are important to OPIE. One is the
   "seed" or "key", consisting of two letters and five digits. The other is
   the "iteration count", a number between 1 and 100. OPIE creates the
   one-time password by concatenating the seed and the secret password,
   applying the MD5 hash as many times as specified by the iteration count,
   and turning the result into six short English words which represent the
   one-time password. The authentication system keeps track of the last
   one-time password used, and the user is authenticated if the hash of the
   user-provided password is equal to the previous password. Since a one-way
   hash is used, it is impossible to generate future one-time passwords if a
   successfully used password is captured. The iteration count is decremented
   after each successful login to keep the user and the login program in
   sync. When the iteration count gets down to 1, OPIE must be reinitialized.

   There are a few programs involved in this process. A one-time password, or
   a consecutive list of one-time passwords, is generated by passing an
   iteration count, a seed, and a secret password to opiekey(1). In addition
   to initializing OPIE, opiepasswd(1) is used to change passwords, iteration
   counts, or seeds. The relevant credential files in /etc/opiekeys are
   examined by opieinfo(1) which prints out the invoking user's current
   iteration count and seed.

   This section describes four different sorts of operations. The first is
   how to set up one-time-passwords for the first time over a secure
   connection. The second is how to use opiepasswd over an insecure
   connection. The third is how to log in over an insecure connection. The
   fourth is how to generate a number of keys which can be written down or
   printed out to use at insecure locations.

  14.3.1. Initializing OPIE

   To initialize OPIE for the first time, run this command from a secure
   location:

 % opiepasswd -c
 Adding unfurl:
 Only use this method from the console; NEVER from remote. If you are using
 telnet, xterm, or a dial-in, type ^C now or exit with no password.
 Then run opiepasswd without the -c parameter.
 Using MD5 to compute responses.
 Enter new secret pass phrase:
 Again new secret pass phrase:

 ID unfurl OTP key is 499 to4268
 MOS MALL GOAT ARM AVID COED

   The -c sets console mode which assumes that the command is being run from
   a secure location, such as a computer under the user's control or an SSH
   session to a computer under the user's control.

   When prompted, enter the secret password which will be used to generate
   the one-time login keys. This password should be difficult to guess and
   should be different than the password which is associated with the user's
   login account. It must be between 10 and 127 characters long. Remember
   this password.

   The ID line lists the login name (unfurl), default iteration count (499),
   and default seed (to4268). When logging in, the system will remember these
   parameters and display them, meaning that they do not have to be
   memorized. The last line lists the generated one-time password which
   corresponds to those parameters and the secret password. At the next
   login, use this one-time password.

  14.3.2. Insecure Connection Initialization

   To initialize or change the secret password on an insecure system, a
   secure connection is needed to some place where opiekey can be run. This
   might be a shell prompt on a trusted machine. An iteration count is
   needed, where 100 is probably a good value, and the seed can either be
   specified or the randomly-generated one used. On the insecure connection,
   the machine being initialized, use opiepasswd(1):

 % opiepasswd

 Updating unfurl:
 You need the response from an OTP generator.
 Old secret pass phrase:
         otp-md5 498 to4268 ext
         Response: GAME GAG WELT OUT DOWN CHAT
 New secret pass phrase:
         otp-md5 499 to4269
         Response: LINE PAP MILK NELL BUOY TROY

 ID mark OTP key is 499 gr4269
 LINE PAP MILK NELL BUOY TROY

   To accept the default seed, press Return. Before entering an access
   password, move over to the secure connection and give it the same
   parameters:

 % opiekey 498 to4268
 Using the MD5 algorithm to compute response.
 Reminder: Do not use opiekey from telnet or dial-in sessions.
 Enter secret pass phrase:
 GAME GAG WELT OUT DOWN CHAT

   Switch back over to the insecure connection, and copy the generated
   one-time password over to the relevant program.

  14.3.3. Generating a Single One-time Password

   After initializing OPIE and logging in, a prompt like this will be
   displayed:

 % telnet example.com
 Trying 10.0.0.1...
 Connected to example.com
 Escape character is '^]'.

 FreeBSD/i386 (example.com) (ttypa)

 login: <username>
 otp-md5 498 gr4269 ext
 Password:

   The OPIE prompts provides a useful feature. If Return is pressed at the
   password prompt, the prompt will turn echo on and display what is typed.
   This can be useful when attempting to type in a password by hand from a
   printout.

   At this point, generate the one-time password to answer this login prompt.
   This must be done on a trusted system where it is safe to run opiekey(1).
   There are versions of this command for Windows(R), Mac OS(R) and FreeBSD.
   This command needs the iteration count and the seed as command line
   options. Use cut-and-paste from the login prompt on the machine being
   logged in to.

   On the trusted system:

 % opiekey 498 to4268
 Using the MD5 algorithm to compute response.
 Reminder: Do not use opiekey from telnet or dial-in sessions.
 Enter secret pass phrase:
 GAME GAG WELT OUT DOWN CHAT

   Once the one-time password is generated, continue to log in.

  14.3.4. Generating Multiple One-time Passwords

   Sometimes there is no access to a trusted machine or secure connection. In
   this case, it is possible to use opiekey(1) to generate a number of
   one-time passwords beforehand. For example:

 % opiekey -n 5 30 zz99999
 Using the MD5 algorithm to compute response.
 Reminder: Do not use opiekey from telnet or dial-in sessions.
 Enter secret pass phrase: <secret password>
 26: JOAN BORE FOSS DES NAY QUIT
 27: LATE BIAS SLAY FOLK MUCH TRIG
 28: SALT TIN ANTI LOON NEAL USE
 29: RIO ODIN GO BYE FURY TIC
 30: GREW JIVE SAN GIRD BOIL PHI

   The -n 5 requests five keys in sequence, and 30 specifies what the last
   iteration number should be. Note that these are printed out in reverse
   order of use. The really paranoid might want to write the results down by
   hand; otherwise, print the list. Each line shows both the iteration count
   and the one-time password. Scratch off the passwords as they are used.

  14.3.5. Restricting Use of UNIX(R) Passwords

   OPIE can restrict the use of UNIX(R) passwords based on the IP address of
   a login session. The relevant file is /etc/opieaccess, which is present by
   default. Refer to opieaccess(5) for more information on this file and
   which security considerations to be aware of when using it.

   Here is a sample opieaccess:

 permit 192.168.0.0 255.255.0.0

   This line allows users whose IP source address (which is vulnerable to
   spoofing) matches the specified value and mask, to use UNIX(R) passwords
   at any time.

   If no rules in opieaccess are matched, the default is to deny non-OPIE
   logins.

14.4. TCP Wrapper

   Written by Tom Rhodes.

   TCP Wrapper is a host-based access control system which extends the
   abilities of Section 30.2, "The inetd Super-Server". It can be configured
   to provide logging support, return messages, and connection restrictions
   for the server daemons under the control of inetd. Refer to tcpd(8) for
   more information about TCP Wrapper and its features.

   TCP Wrapper should not be considered a replacement for a properly
   configured firewall. Instead, TCP Wrapper should be used in conjunction
   with a firewall and other security enhancements in order to provide
   another layer of protection in the implementation of a security policy.

  14.4.1. Initial Configuration

   To enable TCP Wrapper in FreeBSD, add the following lines to /etc/rc.conf:

 inetd_enable="YES"
 inetd_flags="-Ww"

   Then, properly configure /etc/hosts.allow.

  Note:

   Unlike other implementations of TCP Wrapper, the use of hosts.deny is
   deprecated in FreeBSD. All configuration options should be placed in
   /etc/hosts.allow.

   In the simplest configuration, daemon connection policies are set to
   either permit or block, depending on the options in /etc/hosts.allow. The
   default configuration in FreeBSD is to allow all connections to the
   daemons started with inetd.

   Basic configuration usually takes the form of daemon : address : action,
   where daemon is the daemon which inetd started, address is a valid
   hostname, IP address, or an IPv6 address enclosed in brackets ([ ]), and
   action is either allow or deny. TCP Wrapper uses a first rule match
   semantic, meaning that the configuration file is scanned from the
   beginning for a matching rule. When a match is found, the rule is applied
   and the search process stops.

   For example, to allow POP3 connections via the mail/qpopper daemon, the
   following lines should be appended to hosts.allow:

 # This line is required for POP3 connections:
 qpopper : ALL : allow

   Whenever this file is edited, restart inetd:

 # service inetd restart

  14.4.2. Advanced Configuration

   TCP Wrapper provides advanced options to allow more control over the way
   connections are handled. In some cases, it may be appropriate to return a
   comment to certain hosts or daemon connections. In other cases, a log
   entry should be recorded or an email sent to the administrator. Other
   situations may require the use of a service for local connections only.
   This is all possible through the use of configuration options known as
   wildcards, expansion characters, and external command execution.

   Suppose that a situation occurs where a connection should be denied yet a
   reason should be sent to the host who attempted to establish that
   connection. That action is possible with twist. When a connection attempt
   is made, twist executes a shell command or script. An example exists in
   hosts.allow:

 # The rest of the daemons are protected.
 ALL : ALL \
         : severity auth.info \
         : twist /bin/echo "You are not welcome to use %d from %h."

   In this example, the message "You are not allowed to use daemon name from
   hostname." will be returned for any daemon not configured in hosts.allow.
   This is useful for sending a reply back to the connection initiator right
   after the established connection is dropped. Any message returned must be
   wrapped in quote (") characters.

  Warning:

   It may be possible to launch a denial of service attack on the server if
   an attacker floods these daemons with connection requests.

   Another possibility is to use spawn. Like twist, spawn implicitly denies
   the connection and may be used to run external shell commands or scripts.
   Unlike twist, spawn will not send a reply back to the host who established
   the connection. For example, consider the following configuration:

 # We do not allow connections from example.com:
 ALL : .example.com \
         : spawn (/bin/echo %a from %h attempted to access %d >> \
           /var/log/connections.log) \
         : deny

   This will deny all connection attempts from *.example.com and log the
   hostname, IP address, and the daemon to which access was attempted to
   /var/log/connections.log. This example uses the substitution characters %a
   and %h. Refer to hosts_access(5) for the complete list.

   To match every instance of a daemon, domain, or IP address, use ALL.
   Another wildcard is PARANOID which may be used to match any host which
   provides an IP address that may be forged because the IP address differs
   from its resolved hostname. In this example, all connection requests to
   Sendmail which have an IP address that varies from its hostname will be
   denied:

 # Block possibly spoofed requests to sendmail:
 sendmail : PARANOID : deny

  Caution:

   Using the PARANOID wildcard will result in denied connections if the
   client or server has a broken DNS setup.

   To learn more about wildcards and their associated functionality, refer to
   hosts_access(5).

  Note:

   When adding new configuration lines, make sure that any unneeded entries
   for that daemon are commented out in hosts.allow.

14.5. Kerberos

   Contributed by Tillman Hodgson.
   Based on a contribution by Mark Murray.

   Kerberos is a network authentication protocol which was originally created
   by the Massachusetts Institute of Technology (MIT) as a way to securely
   provide authentication across a potentially hostile network. The Kerberos
   protocol uses strong cryptography so that both a client and server can
   prove their identity without sending any unencrypted secrets over the
   network. Kerberos can be described as an identity-verifying proxy system
   and as a trusted third-party authentication system. After a user
   authenticates with Kerberos, their communications can be encrypted to
   assure privacy and data integrity.

   The only function of Kerberos is to provide the secure authentication of
   users and servers on the network. It does not provide authorization or
   auditing functions. It is recommended that Kerberos be used with other
   security methods which provide authorization and audit services.

   The current version of the protocol is version 5, described in RFC 4120.
   Several free implementations of this protocol are available, covering a
   wide range of operating systems. MIT continues to develop their Kerberos
   package. It is commonly used in the US as a cryptography product, and has
   historically been subject to US export regulations. In FreeBSD, MIT
   Kerberos is available as the security/krb5 package or port. The Heimdal
   Kerberos implementation was explicitly developed outside of the US to
   avoid export regulations. The Heimdal Kerberos distribution is included in
   the base FreeBSD installation, and another distribution with more
   configurable options is available as security/heimdal in the Ports
   Collection.

   In Kerberos users and services are identified as "principals" which are
   contained within an administrative grouping, called a "realm". A typical
   user principal would be of the form user@REALM (realms are traditionally
   uppercase).

   This section provides a guide on how to set up Kerberos using the Heimdal
   distribution included in FreeBSD.

   For purposes of demonstrating a Kerberos installation, the name spaces
   will be as follows:

     * The DNS domain (zone) will be example.org.

     * The Kerberos realm will be EXAMPLE.ORG.

  Note:

   Use real domain names when setting up Kerberos, even if it will run
   internally. This avoids DNS problems and assures inter-operation with
   other Kerberos realms.

  14.5.1. Setting up a Heimdal KDC

   The Key Distribution Center (KDC) is the centralized authentication
   service that Kerberos provides, the "trusted third party" of the system.
   It is the computer that issues Kerberos tickets, which are used for
   clients to authenticate to servers. As the KDC is considered trusted by
   all other computers in the Kerberos realm, it has heightened security
   concerns. Direct access to the KDC should be limited.

   While running a KDC requires few computing resources, a dedicated machine
   acting only as a KDC is recommended for security reasons.

   To begin, install the security/heimdal package as follows:

 # pkg install heimdal

   Next, update /etc/rc.conf using sysrc as follows:

 # sysrc kdc_enable=yes
 # sysrc kadmind_enable=yes

   Next, edit /etc/krb5.conf as follows:

 [libdefaults]
     default_realm = EXAMPLE.ORG
 [realms]
     EXAMPLE.ORG = {
         kdc = kerberos.example.org
         admin_server = kerberos.example.org
     }
 [domain_realm]
     .example.org = EXAMPLE.ORG

   In this example, the KDC will use the fully-qualified hostname
   kerberos.example.org. The hostname of the KDC must be resolvable in the
   DNS.

   Kerberos can also use the DNS to locate KDCs, instead of a [realms]
   section in /etc/krb5.conf. For large organizations that have their own DNS
   servers, the above example could be trimmed to:

 [libdefaults]
       default_realm = EXAMPLE.ORG
 [domain_realm]
     .example.org = EXAMPLE.ORG

   With the following lines being included in the example.org zone file:

 _kerberos._udp      IN  SRV     01 00 88 kerberos.example.org.
 _kerberos._tcp      IN  SRV     01 00 88 kerberos.example.org.
 _kpasswd._udp       IN  SRV     01 00 464 kerberos.example.org.
 _kerberos-adm._tcp  IN  SRV     01 00 749 kerberos.example.org.
 _kerberos           IN  TXT     EXAMPLE.ORG

  Note:

   In order for clients to be able to find the Kerberos services, they must
   have either a fully configured /etc/krb5.conf or a minimally configured
   /etc/krb5.conf and a properly configured DNS server.

   Next, create the Kerberos database which contains the keys of all
   principals (users and hosts) encrypted with a master password. It is not
   required to remember this password as it will be stored in
   /var/heimdal/m-key; it would be reasonable to use a 45-character random
   password for this purpose. To create the master key, run kstash and enter
   a password:

 # kstash
 Master key: xxxxxxxxxxxxxxxxxxxxxxx
 Verifying password - Master key: xxxxxxxxxxxxxxxxxxxxxxx

   Once the master key has been created, the database should be initialized.
   The Kerberos administrative tool kadmin(8) can be used on the KDC in a
   mode that operates directly on the database, without using the kadmind(8)
   network service, as kadmin -l. This resolves the chicken-and-egg problem
   of trying to connect to the database before it is created. At the kadmin
   prompt, use init to create the realm's initial database:

 # kadmin -l
 kadmin> init EXAMPLE.ORG
 Realm max ticket life [unlimited]:

   Lastly, while still in kadmin, create the first principal using add. Stick
   to the default options for the principal for now, as these can be changed
   later with modify. Type ? at the prompt to see the available options.

 kadmin> add tillman
 Max ticket life [unlimited]:
 Max renewable life [unlimited]:
 Principal expiration time [never]:
 Password expiration time [never]:
 Attributes []:
 Password: xxxxxxxx
 Verifying password - Password: xxxxxxxx

   Next, start the KDC services by running:

 # service kdc start
 # service kadmind start

   While there will not be any kerberized daemons running at this point, it
   is possible to confirm that the KDC is functioning by obtaining a ticket
   for the principal that was just created:

 % kinit tillman
 tillman@EXAMPLE.ORG's Password:

   Confirm that a ticket was successfully obtained using klist:

 % klist
 Credentials cache: FILE:/tmp/krb5cc_1001
         Principal: tillman@EXAMPLE.ORG

   Issued                Expires               Principal
 Aug 27 15:37:58 2013  Aug 28 01:37:58 2013  krbtgt/EXAMPLE.ORG@EXAMPLE.ORG

   The temporary ticket can be destroyed when the test is finished:

 % kdestroy

  14.5.2. Configuring a Server to Use Kerberos

   The first step in configuring a server to use Kerberos authentication is
   to ensure that it has the correct configuration in /etc/krb5.conf. The
   version from the KDC can be used as-is, or it can be regenerated on the
   new system.

   Next, create /etc/krb5.keytab on the server. This is the main part of
   "Kerberizing" a service - it corresponds to generating a secret shared
   between the service and the KDC. The secret is a cryptographic key, stored
   in a "keytab". The keytab contains the server's host key, which allows it
   and the KDC to verify each others' identity. It must be transmitted to the
   server in a secure fashion, as the security of the server can be broken if
   the key is made public. Typically, the keytab is generated on an
   administrator's trusted machine using kadmin, then securely transferred to
   the server, e.g., with scp(1); it can also be created directly on the
   server if that is consistent with the desired security policy. It is very
   important that the keytab is transmitted to the server in a secure
   fashion: if the key is known by some other party, that party can
   impersonate any user to the server! Using kadmin on the server directly is
   convenient, because the entry for the host principal in the KDC database
   is also created using kadmin.

   Of course, kadmin is a kerberized service; a Kerberos ticket is needed to
   authenticate to the network service, but to ensure that the user running
   kadmin is actually present (and their session has not been hijacked),
   kadmin will prompt for the password to get a fresh ticket. The principal
   authenticating to the kadmin service must be permitted to use the kadmin
   interface, as specified in /var/heimdal/kadmind.acl. See the section
   titled "Remote administration" in info heimdal for details on designing
   access control lists. Instead of enabling remote kadmin access, the
   administrator could securely connect to the KDC via the local console or
   ssh(1), and perform administration locally using kadmin -l.

   After installing /etc/krb5.conf, use add --random-key in kadmin. This adds
   the server's host principal to the database, but does not extract a copy
   of the host principal key to a keytab. To generate the keytab, use ext to
   extract the server's host principal key to its own keytab:

 # kadmin
 kadmin> add --random-key host/myserver.example.org
 Max ticket life [unlimited]:
 Max renewable life [unlimited]:
 Principal expiration time [never]:
 Password expiration time [never]:
 Attributes []:
 kadmin> ext_keytab host/myserver.example.org
 kadmin> exit

   Note that ext_keytab stores the extracted key in /etc/krb5.keytab by
   default. This is good when being run on the server being kerberized, but
   the --keytab path/to/file argument should be used when the keytab is being
   extracted elsewhere:

 # kadmin
 kadmin> ext_keytab --keytab=/tmp/example.keytab host/myserver.example.org
 kadmin> exit

   The keytab can then be securely copied to the server using scp(1) or a
   removable media. Be sure to specify a non-default keytab name to avoid
   inserting unneeded keys into the system's keytab.

   At this point, the server can read encrypted messages from the KDC using
   its shared key, stored in krb5.keytab. It is now ready for the
   Kerberos-using services to be enabled. One of the most common such
   services is sshd(8), which supports Kerberos via the GSS-API. In
   /etc/ssh/sshd_config, add the line:

 GSSAPIAuthentication yes

   After making this change, sshd(8) must be restarted for the new
   configuration to take effect: service sshd restart.

  14.5.3. Configuring a Client to Use Kerberos

   As it was for the server, the client requires configuration in
   /etc/krb5.conf. Copy the file in place (securely) or re-enter it as
   needed.

   Test the client by using kinit, klist, and kdestroy from the client to
   obtain, show, and then delete a ticket for an existing principal. Kerberos
   applications should also be able to connect to Kerberos enabled servers.
   If that does not work but obtaining a ticket does, the problem is likely
   with the server and not with the client or the KDC. In the case of
   kerberized ssh(1), GSS-API is disabled by default, so test using ssh -o
   GSSAPIAuthentication=yes hostname.

   When testing a Kerberized application, try using a packet sniffer such as
   tcpdump to confirm that no sensitive information is sent in the clear.

   Various Kerberos client applications are available. With the advent of a
   bridge so that applications using SASL for authentication can use GSS-API
   mechanisms as well, large classes of client applications can use Kerberos
   for authentication, from Jabber clients to IMAP clients.

   Users within a realm typically have their Kerberos principal mapped to a
   local user account. Occasionally, one needs to grant access to a local
   user account to someone who does not have a matching Kerberos principal.
   For example, tillman@EXAMPLE.ORG may need access to the local user account
   webdevelopers. Other principals may also need access to that local
   account.

   The .k5login and .k5users files, placed in a user's home directory, can be
   used to solve this problem. For example, if the following .k5login is
   placed in the home directory of webdevelopers, both principals listed will
   have access to that account without requiring a shared password:

 tillman@example.org
 jdoe@example.org

   Refer to ksu(1) for more information about .k5users.

  14.5.4. MIT Differences

   The major difference between the MIT and Heimdal implementations is that
   kadmin has a different, but equivalent, set of commands and uses a
   different protocol. If the KDC is MIT, the Heimdal version of kadmin
   cannot be used to administer the KDC remotely, and vice versa.

   Client applications may also use slightly different command line options
   to accomplish the same tasks. Following the instructions at
   http://web.mit.edu/Kerberos/www/ is recommended. Be careful of path
   issues: the MIT port installs into /usr/local/ by default, and the FreeBSD
   system applications run instead of the MIT versions if PATH lists the
   system directories first.

   When using MIT Kerberos as a KDC on FreeBSD, the following edits should
   also be made to rc.conf:

 kdc_program="/usr/local/sbin/kdc"
 kadmind_program="/usr/local/sbin/kadmind"
 kdc_flags=""
 kdc_enable="YES"
 kadmind_enable="YES"

  14.5.5. Kerberos Tips, Tricks, and Troubleshooting

   When configuring and troubleshooting Kerberos, keep the following points
   in mind:

     * When using either Heimdal or MIT Kerberos from ports, ensure that the
       PATH lists the port's versions of the client applications before the
       system versions.

     * If all the computers in the realm do not have synchronized time
       settings, authentication may fail. Section 30.11, "Clock
       Synchronization with NTP" describes how to synchronize clocks using
       NTP.

     * If the hostname is changed, the host/ principal must be changed and
       the keytab updated. This also applies to special keytab entries like
       the HTTP/ principal used for Apache's www/mod_auth_kerb.

     * All hosts in the realm must be both forward and reverse resolvable in
       DNS or, at a minimum, exist in /etc/hosts. CNAMEs will work, but the A
       and PTR records must be correct and in place. The error message for
       unresolvable hosts is not intuitive: Kerberos5 refuses authentication
       because Read req failed: Key table entry not found.

     * Some operating systems that act as clients to the KDC do not set the
       permissions for ksu to be setuid root. This means that ksu does not
       work. This is a permissions problem, not a KDC error.

     * With MIT Kerberos, to allow a principal to have a ticket life longer
       than the default lifetime of ten hours, use modify_principal at the
       kadmin(8) prompt to change the maxlife of both the principal in
       question and the krbtgt principal. The principal can then use kinit -l
       to request a ticket with a longer lifetime.

     * When running a packet sniffer on the KDC to aid in troubleshooting
       while running kinit from a workstation, the Ticket Granting Ticket
       (TGT) is sent immediately, even before the password is typed. This is
       because the Kerberos server freely transmits a TGT to any unauthorized
       request. However, every TGT is encrypted in a key derived from the
       user's password. When a user types their password, it is not sent to
       the KDC, it is instead used to decrypt the TGT that kinit already
       obtained. If the decryption process results in a valid ticket with a
       valid time stamp, the user has valid Kerberos credentials. These
       credentials include a session key for establishing secure
       communications with the Kerberos server in the future, as well as the
       actual TGT, which is encrypted with the Kerberos server's own key.
       This second layer of encryption allows the Kerberos server to verify
       the authenticity of each TGT.

     * Host principals can have a longer ticket lifetime. If the user
       principal has a lifetime of a week but the host being connected to has
       a lifetime of nine hours, the user cache will have an expired host
       principal and the ticket cache will not work as expected.

     * When setting up krb5.dict to prevent specific bad passwords from being
       used as described in kadmind(8), remember that it only applies to
       principals that have a password policy assigned to them. The format
       used in krb5.dict is one string per line. Creating a symbolic link to
       /usr/share/dict/words might be useful.

  14.5.6. Mitigating Kerberos Limitations

   Since Kerberos is an all or nothing approach, every service enabled on the
   network must either be modified to work with Kerberos or be otherwise
   secured against network attacks. This is to prevent user credentials from
   being stolen and re-used. An example is when Kerberos is enabled on all
   remote shells but the non-Kerberized POP3 mail server sends passwords in
   plain text.

   The KDC is a single point of failure. By design, the KDC must be as secure
   as its master password database. The KDC should have absolutely no other
   services running on it and should be physically secure. The danger is high
   because Kerberos stores all passwords encrypted with the same master key
   which is stored as a file on the KDC.

   A compromised master key is not quite as bad as one might fear. The master
   key is only used to encrypt the Kerberos database and as a seed for the
   random number generator. As long as access to the KDC is secure, an
   attacker cannot do much with the master key.

   If the KDC is unavailable, network services are unusable as authentication
   cannot be performed. This can be alleviated with a single master KDC and
   one or more slaves, and with careful implementation of secondary or
   fall-back authentication using PAM.

   Kerberos allows users, hosts and services to authenticate between
   themselves. It does not have a mechanism to authenticate the KDC to the
   users, hosts, or services. This means that a trojaned kinit could record
   all user names and passwords. File system integrity checking tools like
   security/tripwire can alleviate this.

  14.5.7. Resources and Further Information

     * The Kerberos FAQ

     * Designing an Authentication System: a Dialog in Four Scenes

     * RFC 4120, The Kerberos Network Authentication Service (V5)

     * MIT Kerberos home page

     * Heimdal Kerberos project wiki page

14.6. OpenSSL

   Written by Tom Rhodes.

   OpenSSL is an open source implementation of the SSL and TLS protocols. It
   provides an encryption transport layer on top of the normal communications
   layer, allowing it to be intertwined with many network applications and
   services.

   The version of OpenSSL included in FreeBSD supports the Secure Sockets
   Layer 3.0 (SSLv3) and Transport Layer Security 1.0/1.1/1.2
   (TLSv1/TLSv1.1/TLSv1.2) network security protocols and can be used as a
   general cryptographic library. In FreeBSD 12.0-RELEASE and above, OpenSSL
   also supports Transport Layer Security 1.3 (TLSv1.3).

   OpenSSL is often used to encrypt authentication of mail clients and to
   secure web based transactions such as credit card payments. Some ports,
   such as www/apache24 and databases/postgresql11-server, include a compile
   option for building with OpenSSL. If selected, the port will add support
   using OpenSSL from the base system. To instead have the port compile
   against OpenSSL from the security/openssl port, add the following to
   /etc/make.conf:

 DEFAULT_VERSIONS+= ssl=openssl

   Another common use of OpenSSL is to provide certificates for use with
   software applications. Certificates can be used to verify the credentials
   of a company or individual. If a certificate has not been signed by an
   external Certificate Authority (CA), such as http://www.verisign.com, the
   application that uses the certificate will produce a warning. There is a
   cost associated with obtaining a signed certificate and using a signed
   certificate is not mandatory as certificates can be self-signed. However,
   using an external authority will prevent warnings and can put users at
   ease.

   This section demonstrates how to create and use certificates on a FreeBSD
   system. Refer to Section 30.5.2, "Configuring an LDAP Server" for an
   example of how to create a CA for signing one's own certificates.

   For more information about SSL, read the free OpenSSL Cookbook.

  14.6.1. Generating Certificates

   To generate a certificate that will be signed by an external CA, issue the
   following command and input the information requested at the prompts. This
   input information will be written to the certificate. At the Common Name
   prompt, input the fully qualified name for the system that will use the
   certificate. If this name does not match the server, the application
   verifying the certificate will issue a warning to the user, rendering the
   verification provided by the certificate as useless.

 # openssl req -new -nodes -out req.pem -keyout cert.key -sha256 -newkey rsa:2048
 Generating a 2048 bit RSA private key
 ..................+++
 .............................................................+++
 writing new private key to 'cert.key'
 -----
 You are about to be asked to enter information that will be incorporated
 into your certificate request.
 What you are about to enter is what is called a Distinguished Name or a DN.
 There are quite a few fields but you can leave some blank
 For some fields there will be a default value,
 If you enter '.', the field will be left blank.
 -----
 Country Name (2 letter code) [AU]:US
 State or Province Name (full name) [Some-State]:PA
 Locality Name (eg, city) []:Pittsburgh
 Organization Name (eg, company) [Internet Widgits Pty Ltd]:My Company
 Organizational Unit Name (eg, section) []:Systems Administrator
 Common Name (eg, YOUR name) []:localhost.example.org
 Email Address []:trhodes@FreeBSD.org

 Please enter the following 'extra' attributes
 to be sent with your certificate request
 A challenge password []:
 An optional company name []:Another Name

   Other options, such as the expire time and alternate encryption
   algorithms, are available when creating a certificate. A complete list of
   options is described in openssl(1).

   This command will create two files in the current directory. The
   certificate request, req.pem, can be sent to a CA who will validate the
   entered credentials, sign the request, and return the signed certificate.
   The second file, cert.key, is the private key for the certificate and
   should be stored in a secure location. If this falls in the hands of
   others, it can be used to impersonate the user or the server.

   Alternately, if a signature from a CA is not required, a self-signed
   certificate can be created. First, generate the RSA key:

 # openssl genrsa -rand -genkey -out cert.key 2048
 0 semi-random bytes loaded
 Generating RSA private key, 2048 bit long modulus
 .............................................+++
 .................................................................................................................+++
 e is 65537 (0x10001)

   Use this key to create a self-signed certificate. Follow the usual prompts
   for creating a certificate:

 # openssl req -new -x509 -days 365 -key cert.key -out cert.crt -sha256
 You are about to be asked to enter information that will be incorporated
 into your certificate request.
 What you are about to enter is what is called a Distinguished Name or a DN.
 There are quite a few fields but you can leave some blank
 For some fields there will be a default value,
 If you enter '.', the field will be left blank.
 -----
 Country Name (2 letter code) [AU]:US
 State or Province Name (full name) [Some-State]:PA
 Locality Name (eg, city) []:Pittsburgh
 Organization Name (eg, company) [Internet Widgits Pty Ltd]:My Company
 Organizational Unit Name (eg, section) []:Systems Administrator
 Common Name (e.g. server FQDN or YOUR name) []:localhost.example.org
 Email Address []:trhodes@FreeBSD.org

   This will create two new files in the current directory: a private key
   file cert.key, and the certificate itself, cert.crt. These should be
   placed in a directory, preferably under /etc/ssl/, which is readable only
   by root. Permissions of 0700 are appropriate for these files and can be
   set using chmod.

  14.6.2. Using Certificates

   One use for a certificate is to encrypt connections to the Sendmail mail
   server in order to prevent the use of clear text authentication.

  Note:

   Some mail clients will display an error if the user has not installed a
   local copy of the certificate. Refer to the documentation included with
   the software for more information on certificate installation.

   In FreeBSD 10.0-RELEASE and above, it is possible to create a self-signed
   certificate for Sendmail automatically. To enable this, add the following
   lines to /etc/rc.conf:

 sendmail_enable="YES"
 sendmail_cert_create="YES"
 sendmail_cert_cn="localhost.example.org"

   This will automatically create a self-signed certificate,
   /etc/mail/certs/host.cert, a signing key, /etc/mail/certs/host.key, and a
   CA certificate, /etc/mail/certs/cacert.pem. The certificate will use the
   Common Name specified in sendmail_cert_cn. After saving the edits, restart
   Sendmail:

 # service sendmail restart

   If all went well, there will be no error messages in /var/log/maillog. For
   a simple test, connect to the mail server's listening port using telnet:

 # telnet example.com 25
 Trying 192.0.34.166...
 Connected to example.com.
 Escape character is '^]'.
 220 example.com ESMTP Sendmail 8.14.7/8.14.7; Fri, 18 Apr 2014 11:50:32 -0400 (EDT)
 ehlo example.com
 250-example.com Hello example.com [192.0.34.166], pleased to meet you
 250-ENHANCEDSTATUSCODES
 250-PIPELINING
 250-8BITMIME
 250-SIZE
 250-DSN
 250-ETRN
 250-AUTH LOGIN PLAIN
 250-STARTTLS
 250-DELIVERBY
 250 HELP
 quit
 221 2.0.0 example.com closing connection
 Connection closed by foreign host.

   If the STARTTLS line appears in the output, everything is working
   correctly.

14.7. VPN over IPsec

   Written by Nik Clayton.
   Written by Hiten M. Pandya.

   Internet Protocol Security (IPsec) is a set of protocols which sit on top
   of the Internet Protocol (IP) layer. It allows two or more hosts to
   communicate in a secure manner by authenticating and encrypting each IP
   packet of a communication session. The FreeBSD IPsec network stack is
   based on the http://www.kame.net/ implementation and supports both IPv4
   and IPv6 sessions.

   IPsec is comprised of the following sub-protocols:

     * Encapsulated Security Payload (ESP): this protocol protects the IP
       packet data from third party interference by encrypting the contents
       using symmetric cryptography algorithms such as Blowfish and 3DES.

     * Authentication Header (AH): this protocol protects the IP packet
       header from third party interference and spoofing by computing a
       cryptographic checksum and hashing the IP packet header fields with a
       secure hashing function. This is then followed by an additional header
       that contains the hash, to allow the information in the packet to be
       authenticated.

     * IP Payload Compression Protocol (IPComp): this protocol tries to
       increase communication performance by compressing the IP payload in
       order to reduce the amount of data sent.

   These protocols can either be used together or separately, depending on
   the environment.

   IPsec supports two modes of operation. The first mode, Transport Mode,
   protects communications between two hosts. The second mode, Tunnel Mode,
   is used to build virtual tunnels, commonly known as Virtual Private
   Networks (VPNs). Consult ipsec(4) for detailed information on the IPsec
   subsystem in FreeBSD.

   IPsec support is enabled by default on FreeBSD 11 and later. For previous
   versions of FreeBSD, add these options to a custom kernel configuration
   file and rebuild the kernel using the instructions in Chapter 8,
   Configuring the FreeBSD Kernel:

 options   IPSEC        #IP security
 device    crypto

   If IPsec debugging support is desired, the following kernel option should
   also be added:

 options   IPSEC_DEBUG  #debug for IP security

   This rest of this chapter demonstrates the process of setting up an IPsec
   VPN between a home network and a corporate network. In the example
   scenario:

     * Both sites are connected to the Internet through a gateway that is
       running FreeBSD.

     * The gateway on each network has at least one external IP address. In
       this example, the corporate LAN's external IP address is 172.16.5.4
       and the home LAN's external IP address is 192.168.1.12.

     * The internal addresses of the two networks can be either public or
       private IP addresses. However, the address space must not collide. For
       example, both networks cannot use 192.168.1.x. In this example, the
       corporate LAN's internal IP address is 10.246.38.1 and the home LAN's
       internal IP address is 10.0.0.5.

  14.7.1. Configuring a VPN on FreeBSD

   Written by Tom Rhodes.

   To begin, security/ipsec-tools must be installed from the Ports
   Collection. This software provides a number of applications which support
   the configuration.

   The next requirement is to create two gif(4) pseudo-devices which will be
   used to tunnel packets and allow both networks to communicate properly. As
   root, run the following commands, replacing internal and external with the
   real IP addresses of the internal and external interfaces of the two
   gateways:

 # ifconfig gif0 create
 # ifconfig gif0 internal1 internal2
 # ifconfig gif0 tunnel external1 external2

   Verify the setup on each gateway, using ifconfig. Here is the output from
   Gateway 1:

 gif0: flags=8051 mtu 1280
 tunnel inet 172.16.5.4 --> 192.168.1.12
 inet6 fe80::2e0:81ff:fe02:5881%gif0 prefixlen 64 scopeid 0x6
 inet 10.246.38.1 --> 10.0.0.5 netmask 0xffffff00

   Here is the output from Gateway 2:

 gif0: flags=8051 mtu 1280
 tunnel inet 192.168.1.12 --> 172.16.5.4
 inet 10.0.0.5 --> 10.246.38.1 netmask 0xffffff00
 inet6 fe80::250:bfff:fe3a:c1f%gif0 prefixlen 64 scopeid 0x4

   Once complete, both internal IP addresses should be reachable using
   ping(8):

 priv-net# ping 10.0.0.5
 PING 10.0.0.5 (10.0.0.5): 56 data bytes
 64 bytes from 10.0.0.5: icmp_seq=0 ttl=64 time=42.786 ms
 64 bytes from 10.0.0.5: icmp_seq=1 ttl=64 time=19.255 ms
 64 bytes from 10.0.0.5: icmp_seq=2 ttl=64 time=20.440 ms
 64 bytes from 10.0.0.5: icmp_seq=3 ttl=64 time=21.036 ms
 --- 10.0.0.5 ping statistics ---
 4 packets transmitted, 4 packets received, 0% packet loss
 round-trip min/avg/max/stddev = 19.255/25.879/42.786/9.782 ms

 corp-net# ping 10.246.38.1
 PING 10.246.38.1 (10.246.38.1): 56 data bytes
 64 bytes from 10.246.38.1: icmp_seq=0 ttl=64 time=28.106 ms
 64 bytes from 10.246.38.1: icmp_seq=1 ttl=64 time=42.917 ms
 64 bytes from 10.246.38.1: icmp_seq=2 ttl=64 time=127.525 ms
 64 bytes from 10.246.38.1: icmp_seq=3 ttl=64 time=119.896 ms
 64 bytes from 10.246.38.1: icmp_seq=4 ttl=64 time=154.524 ms
 --- 10.246.38.1 ping statistics ---
 5 packets transmitted, 5 packets received, 0% packet loss
 round-trip min/avg/max/stddev = 28.106/94.594/154.524/49.814 ms

   As expected, both sides have the ability to send and receive ICMP packets
   from the privately configured addresses. Next, both gateways must be told
   how to route packets in order to correctly send traffic from either
   network. The following commands will achieve this goal:

 corp-net# route add 10.0.0.0 10.0.0.5 255.255.255.0
 corp-net# route add net 10.0.0.0: gateway 10.0.0.5

 priv-net# route add 10.246.38.0 10.246.38.1 255.255.255.0
 priv-net# route add host 10.246.38.0: gateway 10.246.38.1

   At this point, internal machines should be reachable from each gateway as
   well as from machines behind the gateways. Again, use ping(8) to confirm:

 corp-net# ping 10.0.0.8
 PING 10.0.0.8 (10.0.0.8): 56 data bytes
 64 bytes from 10.0.0.8: icmp_seq=0 ttl=63 time=92.391 ms
 64 bytes from 10.0.0.8: icmp_seq=1 ttl=63 time=21.870 ms
 64 bytes from 10.0.0.8: icmp_seq=2 ttl=63 time=198.022 ms
 64 bytes from 10.0.0.8: icmp_seq=3 ttl=63 time=22.241 ms
 64 bytes from 10.0.0.8: icmp_seq=4 ttl=63 time=174.705 ms
 --- 10.0.0.8 ping statistics ---
 5 packets transmitted, 5 packets received, 0% packet loss
 round-trip min/avg/max/stddev = 21.870/101.846/198.022/74.001 ms

 priv-net# ping 10.246.38.107
 PING 10.246.38.1 (10.246.38.107): 56 data bytes
 64 bytes from 10.246.38.107: icmp_seq=0 ttl=64 time=53.491 ms
 64 bytes from 10.246.38.107: icmp_seq=1 ttl=64 time=23.395 ms
 64 bytes from 10.246.38.107: icmp_seq=2 ttl=64 time=23.865 ms
 64 bytes from 10.246.38.107: icmp_seq=3 ttl=64 time=21.145 ms
 64 bytes from 10.246.38.107: icmp_seq=4 ttl=64 time=36.708 ms
 --- 10.246.38.107 ping statistics ---
 5 packets transmitted, 5 packets received, 0% packet loss
 round-trip min/avg/max/stddev = 21.145/31.721/53.491/12.179 ms

   Setting up the tunnels is the easy part. Configuring a secure link is a
   more in depth process. The following configuration uses pre-shared (PSK)
   RSA keys. Other than the IP addresses, the
   /usr/local/etc/racoon/racoon.conf on both gateways will be identical and
   look similar to:

 path    pre_shared_key  "/usr/local/etc/racoon/psk.txt"; #location of pre-shared key file
 log     debug;  #log verbosity setting: set to 'notify' when testing and debugging is complete

 padding # options are not to be changed
 {
         maximum_length  20;
         randomize       off;
         strict_check    off;
         exclusive_tail  off;
 }

 timer   # timing options. change as needed
 {
         counter         5;
         interval        20 sec;
         persend         1;
 #       natt_keepalive  15 sec;
         phase1          30 sec;
         phase2          15 sec;
 }

 listen  # address [port] that racoon will listen on
 {
         isakmp          172.16.5.4 [500];
         isakmp_natt     172.16.5.4 [4500];
 }

 remote  192.168.1.12 [500]
 {
         exchange_mode   main,aggressive;
         doi             ipsec_doi;
         situation       identity_only;
         my_identifier   address 172.16.5.4;
         peers_identifier        address 192.168.1.12;
         lifetime        time 8 hour;
         passive         off;
         proposal_check  obey;
 #       nat_traversal   off;
         generate_policy off;

                         proposal {
                                 encryption_algorithm    blowfish;
                                 hash_algorithm          md5;
                                 authentication_method   pre_shared_key;
                                 lifetime time           30 sec;
                                 dh_group                1;
                         }
 }

 sainfo  (address 10.246.38.0/24 any address 10.0.0.0/24 any)    # address $network/$netmask $type address $network/$netmask $type ( $type being any or esp)
 {                                                               # $network must be the two internal networks you are joining.
         pfs_group       1;
         lifetime        time    36000 sec;
         encryption_algorithm    blowfish,3des;
         authentication_algorithm        hmac_md5,hmac_sha1;
         compression_algorithm   deflate;
 }

   For descriptions of each available option, refer to the manual page for
   racoon.conf.

   The Security Policy Database (SPD) needs to be configured so that FreeBSD
   and racoon are able to encrypt and decrypt network traffic between the
   hosts.

   This can be achieved with a shell script, similar to the following, on the
   corporate gateway. This file will be used during system initialization and
   should be saved as /usr/local/etc/racoon/setkey.conf.

 flush;
 spdflush;
 # To the home network
 spdadd 10.246.38.0/24 10.0.0.0/24 any -P out ipsec esp/tunnel/172.16.5.4-192.168.1.12/use;
 spdadd 10.0.0.0/24 10.246.38.0/24 any -P in ipsec esp/tunnel/192.168.1.12-172.16.5.4/use;

   Once in place, racoon may be started on both gateways using the following
   command:

 # /usr/local/sbin/racoon -F -f /usr/local/etc/racoon/racoon.conf -l /var/log/racoon.log

   The output should be similar to the following:

 corp-net# /usr/local/sbin/racoon -F -f /usr/local/etc/racoon/racoon.conf
 Foreground mode.
 2006-01-30 01:35:47: INFO: begin Identity Protection mode.
 2006-01-30 01:35:48: INFO: received Vendor ID: KAME/racoon
 2006-01-30 01:35:55: INFO: received Vendor ID: KAME/racoon
 2006-01-30 01:36:04: INFO: ISAKMP-SA established 172.16.5.4[500]-192.168.1.12[500] spi:623b9b3bd2492452:7deab82d54ff704a
 2006-01-30 01:36:05: INFO: initiate new phase 2 negotiation: 172.16.5.4[0]192.168.1.12[0]
 2006-01-30 01:36:09: INFO: IPsec-SA established: ESP/Tunnel 192.168.1.12[0]->172.16.5.4[0] spi=28496098(0x1b2d0e2)
 2006-01-30 01:36:09: INFO: IPsec-SA established: ESP/Tunnel 172.16.5.4[0]->192.168.1.12[0] spi=47784998(0x2d92426)
 2006-01-30 01:36:13: INFO: respond new phase 2 negotiation: 172.16.5.4[0]192.168.1.12[0]
 2006-01-30 01:36:18: INFO: IPsec-SA established: ESP/Tunnel 192.168.1.12[0]->172.16.5.4[0] spi=124397467(0x76a279b)
 2006-01-30 01:36:18: INFO: IPsec-SA established: ESP/Tunnel 172.16.5.4[0]->192.168.1.12[0] spi=175852902(0xa7b4d66)

   To ensure the tunnel is working properly, switch to another console and
   use tcpdump(1) to view network traffic using the following command.
   Replace em0 with the network interface card as required:

 # tcpdump -i em0 host 172.16.5.4 and dst 192.168.1.12

   Data similar to the following should appear on the console. If not, there
   is an issue and debugging the returned data will be required.

 01:47:32.021683 IP corporatenetwork.com > 192.168.1.12.privatenetwork.com: ESP(spi=0x02acbf9f,seq=0xa)
 01:47:33.022442 IP corporatenetwork.com > 192.168.1.12.privatenetwork.com: ESP(spi=0x02acbf9f,seq=0xb)
 01:47:34.024218 IP corporatenetwork.com > 192.168.1.12.privatenetwork.com: ESP(spi=0x02acbf9f,seq=0xc)

   At this point, both networks should be available and seem to be part of
   the same network. Most likely both networks are protected by a firewall.
   To allow traffic to flow between them, rules need to be added to pass
   packets. For the ipfw(8) firewall, add the following lines to the firewall
   configuration file:

 ipfw add 00201 allow log esp from any to any
 ipfw add 00202 allow log ah from any to any
 ipfw add 00203 allow log ipencap from any to any
 ipfw add 00204 allow log udp from any 500 to any

  Note:

   The rule numbers may need to be altered depending on the current host
   configuration.

   For users of pf(4) or ipf(8), the following rules should do the trick:

 pass in quick proto esp from any to any
 pass in quick proto ah from any to any
 pass in quick proto ipencap from any to any
 pass in quick proto udp from any port = 500 to any port = 500
 pass in quick on gif0 from any to any
 pass out quick proto esp from any to any
 pass out quick proto ah from any to any
 pass out quick proto ipencap from any to any
 pass out quick proto udp from any port = 500 to any port = 500
 pass out quick on gif0 from any to any

   Finally, to allow the machine to start support for the VPN during system
   initialization, add the following lines to /etc/rc.conf:

 ipsec_enable="YES"
 ipsec_program="/usr/local/sbin/setkey"
 ipsec_file="/usr/local/etc/racoon/setkey.conf" # allows setting up spd policies on boot
 racoon_enable="yes"

14.8. OpenSSH

   Contributed by Chern Lee.

   OpenSSH is a set of network connectivity tools used to provide secure
   access to remote machines. Additionally, TCP/IP connections can be
   tunneled or forwarded securely through SSH connections. OpenSSH encrypts
   all traffic to effectively eliminate eavesdropping, connection hijacking,
   and other network-level attacks.

   OpenSSH is maintained by the OpenBSD project and is installed by default
   in FreeBSD. It is compatible with both SSH version 1 and 2 protocols.

   When data is sent over the network in an unencrypted form, network
   sniffers anywhere in between the client and server can steal user/password
   information or data transferred during the session. OpenSSH offers a
   variety of authentication and encryption methods to prevent this from
   happening. More information about OpenSSH is available from
   http://www.openssh.com/.

   This section provides an overview of the built-in client utilities to
   securely access other systems and securely transfer files from a FreeBSD
   system. It then describes how to configure a SSH server on a FreeBSD
   system. More information is available in the man pages mentioned in this
   chapter.

  14.8.1. Using the SSH Client Utilities

   To log into a SSH server, use ssh and specify a username that exists on
   that server and the IP address or hostname of the server. If this is the
   first time a connection has been made to the specified server, the user
   will be prompted to first verify the server's fingerprint:

 # ssh user@example.com
 The authenticity of host 'example.com (10.0.0.1)' can't be established.
 ECDSA key fingerprint is 25:cc:73:b5:b3:96:75:3d:56:19:49:d2:5c:1f:91:3b.
 Are you sure you want to continue connecting (yes/no)? yes
 Permanently added 'example.com' (ECDSA) to the list of known hosts.
 Password for user@example.com: user_password

   SSH utilizes a key fingerprint system to verify the authenticity of the
   server when the client connects. When the user accepts the key's
   fingerprint by typing yes when connecting for the first time, a copy of
   the key is saved to .ssh/known_hosts in the user's home directory. Future
   attempts to login are verified against the saved key and ssh will display
   an alert if the server's key does not match the saved key. If this occurs,
   the user should first verify why the key has changed before continuing
   with the connection.

   By default, recent versions of OpenSSH only accept SSHv2 connections. By
   default, the client will use version 2 if possible and will fall back to
   version 1 if the server does not support version 2. To force ssh to only
   use the specified protocol, include -1 or -2. Additional options are
   described in ssh(1).

   Use scp(1) to securely copy a file to or from a remote machine. This
   example copies COPYRIGHT on the remote system to a file of the same name
   in the current directory of the local system:

 # scp user@example.com:/COPYRIGHT COPYRIGHT
 Password for user@example.com: *******
 COPYRIGHT            100% |*****************************|  4735
 00:00
 #

   Since the fingerprint was already verified for this host, the server's key
   is automatically checked before prompting for the user's password.

   The arguments passed to scp are similar to cp. The file or files to copy
   is the first argument and the destination to copy to is the second. Since
   the file is fetched over the network, one or more of the file arguments
   takes the form user@host:<path_to_remote_file>. Be aware when copying
   directories recursively that scp uses -r, whereas cp uses -R.

   To open an interactive session for copying files, use sftp. Refer to
   sftp(1) for a list of available commands while in an sftp session.

    14.8.1.1. Key-based Authentication

   Instead of using passwords, a client can be configured to connect to the
   remote machine using keys. To generate RSA authentication keys, use
   ssh-keygen. To generate a public and private key pair, specify the type of
   key and follow the prompts. It is recommended to protect the keys with a
   memorable, but hard to guess passphrase.

 % ssh-keygen -t rsa
 Generating public/private rsa key pair.
 Enter file in which to save the key (/home/user/.ssh/id_rsa):
 Enter passphrase (empty for no passphrase):  1
 Enter same passphrase again:                 2
 Your identification has been saved in /home/user/.ssh/id_rsa.
 Your public key has been saved in /home/user/.ssh/id_rsa.pub.
 The key fingerprint is:
 SHA256:54Xm9Uvtv6H4NOo6yjP/YCfODryvUU7yWHzMqeXwhq8 user@host.example.com
 The key's randomart image is:
 +---[RSA 2048]----+
 |                 |
 |                 |
 |                 |
 |        . o..    |
 |       .S*+*o    |
 |      . O=Oo . . |
 |       = Oo= oo..|
 |      .oB.* +.oo.|
 |       =OE**.o..=|
 +----[SHA256]-----+

   1   Type a passphrase here. It can contain spaces and symbols.  
   2   Retype the passphrase to verify it.                         

   The private key is stored in ~/.ssh/id_rsa and the public key is stored in
   ~/.ssh/id_rsa.pub. The public key must be copied to ~/.ssh/authorized_keys
   on the remote machine for key-based authentication to work.

  Warning:

   Many users believe that keys are secure by design and will use a key
   without a passphrase. This is dangerous behavior. An administrator can
   verify that a key pair is protected by a passphrase by viewing the private
   key manually. If the private key file contains the word ENCRYPTED, the key
   owner is using a passphrase. In addition, to better secure end users, from
   may be placed in the public key file. For example, adding
   from="192.168.10.5" in front of the ssh-rsa prefix will only allow that
   specific user to log in from that IP address.

   The options and files vary with different versions of OpenSSH. To avoid
   problems, consult ssh-keygen(1).

   If a passphrase is used, the user is prompted for the passphrase each time
   a connection is made to the server. To load SSH keys into memory and
   remove the need to type the passphrase each time, use ssh-agent(1) and
   ssh-add(1).

   Authentication is handled by ssh-agent, using the private keys that are
   loaded into it. ssh-agent can be used to launch another application like a
   shell or a window manager.

   To use ssh-agent in a shell, start it with a shell as an argument. Add the
   identity by running ssh-add and entering the passphrase for the private
   key. The user will then be able to ssh to any host that has the
   corresponding public key installed. For example:

 % ssh-agent csh
 % ssh-add
 Enter passphrase for key '/usr/home/user/.ssh/id_rsa':  1
 Identity added: /usr/home/user/.ssh/id_rsa (/usr/home/user/.ssh/id_rsa)
 %

   1   Enter the passphrase for the key.  

   To use ssh-agent in Xorg, add an entry for it in ~/.xinitrc. This provides
   the ssh-agent services to all programs launched in Xorg. An example
   ~/.xinitrc might look like this:

 exec ssh-agent startxfce4

   This launches ssh-agent, which in turn launches XFCE, every time Xorg
   starts. Once Xorg has been restarted so that the changes can take effect,
   run ssh-add to load all of the SSH keys.

    14.8.1.2. SSH Tunneling

   OpenSSH has the ability to create a tunnel to encapsulate another protocol
   in an encrypted session.

   The following command tells ssh to create a tunnel for telnet:

 % ssh -2 -N -f -L 5023:localhost:23 user@foo.example.com
 %

   This example uses the following options:

   -2

           Forces ssh to use version 2 to connect to the server.

   -N

           Indicates no command, or tunnel only. If omitted, ssh initiates a
           normal session.

   -f

           Forces ssh to run in the background.

   -L

           Indicates a local tunnel in localport:remotehost:remoteport
           format.

   user@foo.example.com

           The login name to use on the specified remote SSH server.

   An SSH tunnel works by creating a listen socket on localhost on the
   specified localport. It then forwards any connections received on
   localport via the SSH connection to the specified remotehost:remoteport.
   In the example, port 5023 on the client is forwarded to port 23 on the
   remote machine. Since port 23 is used by telnet, this creates an encrypted
   telnet session through an SSH tunnel.

   This method can be used to wrap any number of insecure TCP protocols such
   as SMTP, POP3, and FTP, as seen in the following examples.

   Example 14.1. Create a Secure Tunnel for SMTP

 % ssh -2 -N -f -L 5025:localhost:25 user@mailserver.example.com
 user@mailserver.example.com's password: *****
 % telnet localhost 5025
 Trying 127.0.0.1...
 Connected to localhost.
 Escape character is '^]'.
 220 mailserver.example.com ESMTP

   This can be used in conjunction with ssh-keygen and additional user
   accounts to create a more seamless SSH tunneling environment. Keys can be
   used in place of typing a password, and the tunnels can be run as a
   separate user.

   Example 14.2. Secure Access of a POP3 Server

   In this example, there is an SSH server that accepts connections from the
   outside. On the same network resides a mail server running a POP3 server.
   To check email in a secure manner, create an SSH connection to the SSH
   server and tunnel through to the mail server:

 % ssh -2 -N -f -L 2110:mail.example.com:110 user@ssh-server.example.com
 user@ssh-server.example.com's password: ******

   Once the tunnel is up and running, point the email client to send POP3
   requests to localhost on port 2110. This connection will be forwarded
   securely across the tunnel to mail.example.com.

   Example 14.3. Bypassing a Firewall

   Some firewalls filter both incoming and outgoing connections. For example,
   a firewall might limit access from remote machines to ports 22 and 80 to
   only allow SSH and web surfing. This prevents access to any other service
   which uses a port other than 22 or 80.

   The solution is to create an SSH connection to a machine outside of the
   network's firewall and use it to tunnel to the desired service:

 % ssh -2 -N -f -L 8888:music.example.com:8000 user@unfirewalled-system.example.org
 user@unfirewalled-system.example.org's password: *******

   In this example, a streaming Ogg Vorbis client can now be pointed to
   localhost port 8888, which will be forwarded over to music.example.com on
   port 8000, successfully bypassing the firewall.

  14.8.2. Enabling the SSH Server

   In addition to providing built-in SSH client utilities, a FreeBSD system
   can be configured as an SSH server, accepting connections from other SSH
   clients.

   To see if sshd is operating, use the service(8) command:

 # service sshd status

   If the service is not running, add the following line to /etc/rc.conf.

 sshd_enable="YES"

   This will start sshd, the daemon program for OpenSSH, the next time the
   system boots. To start it now:

 # service sshd start

   The first time sshd starts on a FreeBSD system, the system's host keys
   will be automatically created and the fingerprint will be displayed on the
   console. Provide users with the fingerprint so that they can verify it the
   first time they connect to the server.

   Refer to sshd(8) for the list of available options when starting sshd and
   a more complete discussion about authentication, the login process, and
   the various configuration files.

   At this point, the sshd should be available to all users with a username
   and password on the system.

  14.8.3. SSH Server Security

   While sshd is the most widely used remote administration facility for
   FreeBSD, brute force and drive by attacks are common to any system exposed
   to public networks. Several additional parameters are available to prevent
   the success of these attacks and will be described in this section.

   It is a good idea to limit which users can log into the SSH server and
   from where using the AllowUsers keyword in the OpenSSH server
   configuration file. For example, to only allow root to log in from
   192.168.1.32, add this line to /etc/ssh/sshd_config:

 AllowUsers root@192.168.1.32

   To allow admin to log in from anywhere, list that user without specifying
   an IP address:

 AllowUsers admin

   Multiple users should be listed on the same line, like so:

 AllowUsers root@192.168.1.32 admin

   After making changes to /etc/ssh/sshd_config, tell sshd to reload its
   configuration file by running:

 # service sshd reload

  Note:

   When this keyword is used, it is important to list each user that needs to
   log into this machine. Any user that is not specified in that line will be
   locked out. Also, the keywords used in the OpenSSH server configuration
   file are case-sensitive. If the keyword is not spelled correctly,
   including its case, it will be ignored. Always test changes to this file
   to make sure that the edits are working as expected. Refer to
   sshd_config(5) to verify the spelling and use of the available keywords.

   In addition, users may be forced to use two factor authentication via the
   use of a public and private key. When required, the user may generate a
   key pair through the use of ssh-keygen(1) and send the administrator the
   public key. This key file will be placed in the authorized_keys as
   described above in the client section. To force the users to use keys
   only, the following option may be configured:

 AuthenticationMethods publickey

  Tip:

   Do not confuse /etc/ssh/sshd_config with /etc/ssh/ssh_config (note the
   extra d in the first filename). The first file configures the server and
   the second file configures the client. Refer to ssh_config(5) for a
   listing of the available client settings.

14.9. Access Control Lists

   Contributed by Tom Rhodes.

   Access Control Lists (ACLs) extend the standard UNIX(R) permission model
   in a POSIX(R).1e compatible way. This permits an administrator to take
   advantage of a more fine-grained permissions model.

   The FreeBSD GENERIC kernel provides ACL support for UFS file systems.
   Users who prefer to compile a custom kernel must include the following
   option in their custom kernel configuration file:

 options UFS_ACL

   If this option is not compiled in, a warning message will be displayed
   when attempting to mount a file system with ACL support. ACLs rely on
   extended attributes which are natively supported in UFS2.

   This chapter describes how to enable ACL support and provides some usage
   examples.

  14.9.1. Enabling ACL Support

   ACLs are enabled by the mount-time administrative flag, acls, which may be
   added to /etc/fstab. The mount-time flag can also be automatically set in
   a persistent manner using tunefs(8) to modify a superblock ACLs flag in
   the file system header. In general, it is preferred to use the superblock
   flag for several reasons:

     * The superblock flag cannot be changed by a remount using mount -u as
       it requires a complete umount and fresh mount. This means that ACLs
       cannot be enabled on the root file system after boot. It also means
       that ACL support on a file system cannot be changed while the system
       is in use.

     * Setting the superblock flag causes the file system to always be
       mounted with ACLs enabled, even if there is not an fstab entry or if
       the devices re-order. This prevents accidental mounting of the file
       system without ACL support.

  Note:

   It is desirable to discourage accidental mounting without ACLs enabled
   because nasty things can happen if ACLs are enabled, then disabled, then
   re-enabled without flushing the extended attributes. In general, once ACLs
   are enabled on a file system, they should not be disabled, as the
   resulting file protections may not be compatible with those intended by
   the users of the system, and re-enabling ACLs may re-attach the previous
   ACLs to files that have since had their permissions changed, resulting in
   unpredictable behavior.

   File systems with ACLs enabled will show a plus (+) sign in their
   permission settings:

 drwx------  2 robert  robert  512 Dec 27 11:54 private
 drwxrwx---+ 2 robert  robert  512 Dec 23 10:57 directory1
 drwxrwx---+ 2 robert  robert  512 Dec 22 10:20 directory2
 drwxrwx---+ 2 robert  robert  512 Dec 27 11:57 directory3
 drwxr-xr-x  2 robert  robert  512 Nov 10 11:54 public_html

   In this example, directory1, directory2, and directory3 are all taking
   advantage of ACLs, whereas private and public_html are not.

  14.9.2. Using ACLs

   File system ACLs can be viewed using getfacl. For instance, to view the
   ACL settings on test:

 % getfacl test
         #file:test
         #owner:1001
         #group:1001
         user::rw-
         group::r--
         other::r--

   To change the ACL settings on this file, use setfacl. To remove all of the
   currently defined ACLs from a file or file system, include -k. However,
   the preferred method is to use -b as it leaves the basic fields required
   for ACLs to work.

 % setfacl -k test

   To modify the default ACL entries, use -m:

 % setfacl -m u:trhodes:rwx,group:web:r--,o::--- test

   In this example, there were no pre-defined entries, as they were removed
   by the previous command. This command restores the default options and
   assigns the options listed. If a user or group is added which does not
   exist on the system, an Invalid argument error will be displayed.

   Refer to getfacl(1) and setfacl(1) for more information about the options
   available for these commands.

14.10. Monitoring Third Party Security Issues

   Contributed by Tom Rhodes.

   In recent years, the security world has made many improvements to how
   vulnerability assessment is handled. The threat of system intrusion
   increases as third party utilities are installed and configured for
   virtually any operating system available today.

   Vulnerability assessment is a key factor in security. While FreeBSD
   releases advisories for the base system, doing so for every third party
   utility is beyond the FreeBSD Project's capability. There is a way to
   mitigate third party vulnerabilities and warn administrators of known
   security issues. A FreeBSD add on utility known as pkg includes options
   explicitly for this purpose.

   pkg polls a database for security issues. The database is updated and
   maintained by the FreeBSD Security Team and ports developers.

   Please refer to instructions for installing pkg.

   Installation provides periodic(8) configuration files for maintaining the
   pkg audit database, and provides a programmatic method of keeping it
   updated. This functionality is enabled if
   daily_status_security_pkgaudit_enable is set to YES in periodic.conf(5).
   Ensure that daily security run emails, which are sent to root's email
   account, are being read.

   After installation, and to audit third party utilities as part of the
   Ports Collection at any time, an administrator may choose to update the
   database and view known vulnerabilities of installed packages by invoking:

 # pkg audit -F

   pkg displays messages any published vulnerabilities in installed packages:

 Affected package: cups-base-1.1.22.0_1
 Type of problem: cups-base -- HPGL buffer overflow vulnerability.
 Reference: <https://www.FreeBSD.org/ports/portaudit/40a3bca2-6809-11d9-a9e7-0001020eed82.html>

 1 problem(s) in your installed packages found.

 You are advised to update or deinstall the affected package(s) immediately.

   By pointing a web browser to the displayed URL, an administrator may
   obtain more information about the vulnerability. This will include the
   versions affected, by FreeBSD port version, along with other web sites
   which may contain security advisories.

   pkg is a powerful utility and is extremely useful when coupled with
   ports-mgmt/portmaster.

14.11. FreeBSD Security Advisories

   Contributed by Tom Rhodes.

   Like many producers of quality operating systems, the FreeBSD Project has
   a security team which is responsible for determining the End-of-Life (EoL)
   date for each FreeBSD release and to provide security updates for
   supported releases which have not yet reached their EoL. More information
   about the FreeBSD security team and the supported releases is available on
   the FreeBSD security page.

   One task of the security team is to respond to reported security
   vulnerabilities in the FreeBSD operating system. Once a vulnerability is
   confirmed, the security team verifies the steps necessary to fix the
   vulnerability and updates the source code with the fix. It then publishes
   the details as a "Security Advisory". Security advisories are published on
   the FreeBSD website and mailed to the freebsd-security-notifications,
   freebsd-security, and freebsd-announce mailing lists.

   This section describes the format of a FreeBSD security advisory.

  14.11.1. Format of a Security Advisory

   Here is an example of a FreeBSD security advisory:

 =============================================================================
 -----BEGIN PGP SIGNED MESSAGE-----
 Hash: SHA512

 =============================================================================
 FreeBSD-SA-14:04.bind                                       Security Advisory
                                                           The FreeBSD Project

 Topic:          BIND remote denial of service vulnerability

 Category:       contrib
 Module:         bind
 Announced:      2014-01-14
 Credits:        ISC
 Affects:        FreeBSD 8.x and FreeBSD 9.x
 Corrected:      2014-01-14 19:38:37 UTC (stable/9, 9.2-STABLE)
                 2014-01-14 19:42:28 UTC (releng/9.2, 9.2-RELEASE-p3)
                 2014-01-14 19:42:28 UTC (releng/9.1, 9.1-RELEASE-p10)
                 2014-01-14 19:38:37 UTC (stable/8, 8.4-STABLE)
                 2014-01-14 19:42:28 UTC (releng/8.4, 8.4-RELEASE-p7)
                 2014-01-14 19:42:28 UTC (releng/8.3, 8.3-RELEASE-p14)
 CVE Name:       CVE-2014-0591

 For general information regarding FreeBSD Security Advisories,
 including descriptions of the fields above, security branches, and the
 following sections, please visit <URL:http://security.FreeBSD.org/>.

 I.   Background

 BIND 9 is an implementation of the Domain Name System (DNS) protocols.
 The named(8) daemon is an Internet Domain Name Server.

 II.  Problem Description

 Because of a defect in handling queries for NSEC3-signed zones, BIND can
 crash with an "INSIST" failure in name.c when processing queries possessing
 certain properties.  This issue only affects authoritative nameservers with
 at least one NSEC3-signed zone.  Recursive-only servers are not at risk.

 III. Impact

 An attacker who can send a specially crafted query could cause named(8)
 to crash, resulting in a denial of service.

 IV.  Workaround

 No workaround is available, but systems not running authoritative DNS service
 with at least one NSEC3-signed zone using named(8) are not vulnerable.

 V.   Solution

 Perform one of the following:

 1) Upgrade your vulnerable system to a supported FreeBSD stable or
 release / security branch (releng) dated after the correction date.

 2) To update your vulnerable system via a source code patch:

 The following patches have been verified to apply to the applicable
 FreeBSD release branches.

 a) Download the relevant patch from the location below, and verify the
 detached PGP signature using your PGP utility.

 [FreeBSD 8.3, 8.4, 9.1, 9.2-RELEASE and 8.4-STABLE]
 # fetch http://security.FreeBSD.org/patches/SA-14:04/bind-release.patch
 # fetch http://security.FreeBSD.org/patches/SA-14:04/bind-release.patch.asc
 # gpg --verify bind-release.patch.asc

 [FreeBSD 9.2-STABLE]
 # fetch http://security.FreeBSD.org/patches/SA-14:04/bind-stable-9.patch
 # fetch http://security.FreeBSD.org/patches/SA-14:04/bind-stable-9.patch.asc
 # gpg --verify bind-stable-9.patch.asc

 b) Execute the following commands as root:

 # cd /usr/src
 # patch < /path/to/patch

 Recompile the operating system using buildworld and installworld as
 described in <URL:https://www.FreeBSD.org/handbook/makeworld.html>.

 Restart the applicable daemons, or reboot the system.

 3) To update your vulnerable system via a binary patch:

 Systems running a RELEASE version of FreeBSD on the i386 or amd64
 platforms can be updated via the freebsd-update(8) utility:

 # freebsd-update fetch
 # freebsd-update install

 VI.  Correction details

 The following list contains the correction revision numbers for each
 affected branch.

 Branch/path                                                      Revision
 - -------------------------------------------------------------------------
 stable/8/                                                         r260646
 releng/8.3/                                                       r260647
 releng/8.4/                                                       r260647
 stable/9/                                                         r260646
 releng/9.1/                                                       r260647
 releng/9.2/                                                       r260647
 - -------------------------------------------------------------------------

 To see which files were modified by a particular revision, run the
 following command, replacing NNNNNN with the revision number, on a
 machine with Subversion installed:

 # svn diff -cNNNNNN --summarize svn://svn.freebsd.org/base

 Or visit the following URL, replacing NNNNNN with the revision number:

 <URL:https://svnweb.freebsd.org/base?view=revision&revision=NNNNNN>

 VII. References

 <URL:https://kb.isc.org/article/AA-01078>

 <URL:http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-0591>

 The latest revision of this advisory is available at
 <URL:http://security.FreeBSD.org/advisories/FreeBSD-SA-14:04.bind.asc>
 -----BEGIN PGP SIGNATURE-----

 iQIcBAEBCgAGBQJS1ZTYAAoJEO1n7NZdz2rnOvQP/2/68/s9Cu35PmqNtSZVVxVG
 ZSQP5EGWx/lramNf9566iKxOrLRMq/h3XWcC4goVd+gZFrvITJSVOWSa7ntDQ7TO
 XcinfRZ/iyiJbs/Rg2wLHc/t5oVSyeouyccqODYFbOwOlk35JjOTMUG1YcX+Zasg
 ax8RV+7Zt1QSBkMlOz/myBLXUjlTZ3Xg2FXVsfFQW5/g2CjuHpRSFx1bVNX6ysoG
 9DT58EQcYxIS8WfkHRbbXKh9I1nSfZ7/Hky/kTafRdRMrjAgbqFgHkYTYsBZeav5
 fYWKGQRJulYfeZQ90yMTvlpF42DjCC3uJYamJnwDIu8OhS1WRBI8fQfr9DRzmRua
 OK3BK9hUiScDZOJB6OqeVzUTfe7MAA4/UwrDtTYQ+PqAenv1PK8DZqwXyxA9ThHb
 zKO3OwuKOVHJnKvpOcr+eNwo7jbnHlis0oBksj/mrq2P9m2ueF9gzCiq5Ri5Syag
 Wssb1HUoMGwqU0roS8+pRpNC8YgsWpsttvUWSZ8u6Vj/FLeHpiV3mYXPVMaKRhVm
 067BA2uj4Th1JKtGleox+Em0R7OFbCc/9aWC67wiqI6KRyit9pYiF3npph+7D5Eq
 7zPsUdDd+qc+UTiLp3liCRp5w6484wWdhZO6wRtmUgxGjNkxFoNnX8CitzF8AaqO
 UWWemqWuz3lAZuORQ9KX
 =OQzQ
 -----END PGP SIGNATURE-----

   Every security advisory uses the following format:

     * Each security advisory is signed by the PGP key of the Security
       Officer. The public key for the Security Officer can be verified at
       Appendix D, OpenPGP Keys.

     * The name of the security advisory always begins with FreeBSD-SA- (for
       FreeBSD Security Advisory), followed by the year in two digit format
       (14:), followed by the advisory number for that year (04.), followed
       by the name of the affected application or subsystem (bind). The
       advisory shown here is the fourth advisory for 2014 and it affects
       BIND.

     * The Topic field summarizes the vulnerability.

     * The Category refers to the affected part of the system which may be
       one of core, contrib, or ports. The core category means that the
       vulnerability affects a core component of the FreeBSD operating
       system. The contrib category means that the vulnerability affects
       software included with FreeBSD, such as BIND. The ports category
       indicates that the vulnerability affects software available through
       the Ports Collection.

     * The Module field refers to the component location. In this example,
       the bind module is affected; therefore, this vulnerability affects an
       application installed with the operating system.

     * The Announced field reflects the date the security advisory was
       published. This means that the security team has verified that the
       problem exists and that a patch has been committed to the FreeBSD
       source code repository.

     * The Credits field gives credit to the individual or organization who
       noticed the vulnerability and reported it.

     * The Affects field explains which releases of FreeBSD are affected by
       this vulnerability.

     * The Corrected field indicates the date, time, time offset, and
       releases that were corrected. The section in parentheses shows each
       branch for which the fix has been merged, and the version number of
       the corresponding release from that branch. The release identifier
       itself includes the version number and, if appropriate, the patch
       level. The patch level is the letter p followed by a number,
       indicating the sequence number of the patch, allowing users to track
       which patches have already been applied to the system.

     * The CVE Name field lists the advisory number, if one exists, in the
       public cve.mitre.org security vulnerabilities database.

     * The Background field provides a description of the affected module.

     * The Problem Description field explains the vulnerability. This can
       include information about the flawed code and how the utility could be
       maliciously used.

     * The Impact field describes what type of impact the problem could have
       on a system.

     * The Workaround field indicates if a workaround is available to system
       administrators who cannot immediately patch the system .

     * The Solution field provides the instructions for patching the affected
       system. This is a step by step tested and verified method for getting
       a system patched and working securely.

     * The Correction Details field displays each affected Subversion branch
       with the revision number that contains the corrected code.

     * The References field offers sources of additional information
       regarding the vulnerability.

14.12. Process Accounting

   Contributed by Tom Rhodes.

   Process accounting is a security method in which an administrator may keep
   track of system resources used and their allocation among users, provide
   for system monitoring, and minimally track a user's commands.

   Process accounting has both positive and negative points. One of the
   positives is that an intrusion may be narrowed down to the point of entry.
   A negative is the amount of logs generated by process accounting, and the
   disk space they may require. This section walks an administrator through
   the basics of process accounting.

  Note:

   If more fine-grained accounting is needed, refer to Chapter 17, Security
   Event Auditing.

  14.12.1. Enabling and Utilizing Process Accounting

   Before using process accounting, it must be enabled using the following
   commands:

 # sysrc accounting_enable=yes
 # service accounting start

   The accounting information is stored in files located in /var/account,
   which is automatically created, if necessary, the first time the
   accounting service starts. These files contain sensitive information,
   including all the commands issued by all users. Write access to the files
   is limited to root, and read access is limited to root and members of the
   wheel group. To also prevent members of wheel from reading the files,
   change the mode of the /var/account directory to allow access only by
   root.

   Once enabled, accounting will begin to track information such as CPU
   statistics and executed commands. All accounting logs are in a non-human
   readable format which can be viewed using sa. If issued without any
   options, sa prints information relating to the number of per-user calls,
   the total elapsed time in minutes, total CPU and user time in minutes, and
   the average number of I/O operations. Refer to sa(8) for the list of
   available options which control the output.

   To display the commands issued by users, use lastcomm. For example, this
   command prints out all usage of ls by trhodes on the ttyp1 terminal:

 # lastcomm ls trhodes ttyp1

   Many other useful options exist and are explained in lastcomm(1), acct(5),
   and sa(8).

14.13. Resource Limits

   Contributed by Tom Rhodes.

   FreeBSD provides several methods for an administrator to limit the amount
   of system resources an individual may use. Disk quotas limit the amount of
   disk space available to users. Quotas are discussed in Section 18.11,
   "Disk Quotas".

   Limits to other resources, such as CPU and memory, can be set using either
   a flat file or a command to configure a resource limits database. The
   traditional method defines login classes by editing /etc/login.conf. While
   this method is still supported, any changes require a multi-step process
   of editing this file, rebuilding the resource database, making necessary
   changes to /etc/master.passwd, and rebuilding the password database. This
   can become time consuming, depending upon the number of users to
   configure.

   rctl can be used to provide a more fine-grained method for controlling
   resource limits. This command supports more than user limits as it can
   also be used to set resource constraints on processes and jails.

   This section demonstrates both methods for controlling resources,
   beginning with the traditional method.

  14.13.1. Configuring Login Classes

   In the traditional method, login classes and the resource limits to apply
   to a login class are defined in /etc/login.conf. Each user account can be
   assigned to a login class, where default is the default login class. Each
   login class has a set of login capabilities associated with it. A login
   capability is a name=value pair, where name is a well-known identifier and
   value is an arbitrary string which is processed accordingly depending on
   the name.

  Note:

   Whenever /etc/login.conf is edited, the /etc/login.conf.db must be updated
   by executing the following command:

 # cap_mkdb /etc/login.conf

   Resource limits differ from the default login capabilities in two ways.
   First, for every limit, there is a soft and hard limit. A soft limit may
   be adjusted by the user or application, but may not be set higher than the
   hard limit. The hard limit may be lowered by the user, but can only be
   raised by the superuser. Second, most resource limits apply per process to
   a specific user.

   Table 14.1, "Login Class Resource Limits" lists the most commonly used
   resource limits. All of the available resource limits and capabilities are
   described in detail in login.conf(5).

   Table 14.1. Login Class Resource Limits

   Resource Limit                         Description                         
                  The limit on the size of a core file generated by a program 
                  is subordinate to other limits on disk usage, such as       
                  filesize or disk quotas. This limit is often used as a less 
   coredumpsize   severe method of controlling disk space consumption. Since  
                  users do not generate core files and often do not delete    
                  them, this setting may save them from running out of disk   
                  space should a large program crash.                         
                  The maximum amount of CPU time a user's process may         
                  consume. Offending processes will be killed by the kernel.  
   cputime        This is a limit on CPU time consumed, not the percentage of 
                  the CPU as displayed in some of the fields generated by top 
                  and ps.                                                     
                  The maximum size of a file the user may own. Unlike disk    
   filesize       quotas (Section 18.11, "Disk Quotas"), this limit is        
                  enforced on individual files, not the set of all files a    
                  user owns.                                                  
                  The maximum number of foreground and background processes a 
                  user can run. This limit may not be larger than the system  
   maxproc        limit specified by kern.maxproc. Setting this limit too     
                  small may hinder a user's productivity as some tasks, such  
                  as compiling a large program, start lots of processes.      
                  The maximum amount of memory a process may request to be    
                  locked into main memory using mlock(2). Some                
   memorylocked   system-critical programs, such as amd(8), lock into main    
                  memory so that if the system begins to swap, they do not    
                  contribute to disk thrashing.                               
                  The maximum amount of memory a process may consume at any   
   memoryuse      given time. It includes both core memory and swap usage.    
                  This is not a catch-all limit for restricting memory        
                  consumption, but is a good start.                           
                  The maximum number of files a process may have open. In     
   openfiles      FreeBSD, files are used to represent sockets and IPC        
                  channels, so be careful not to set this too low. The        
                  system-wide limit for this is defined by kern.maxfiles.     
                  The limit on the amount of network memory a user may        
   sbsize         consume. This can be generally used to limit network        
                  communications.                                             
                  The maximum size of a process stack. This alone is not      
   stacksize      sufficient to limit the amount of memory a program may use, 
                  so it should be used in conjunction with other limits.      

   There are a few other things to remember when setting resource limits:

     * Processes started at system startup by /etc/rc are assigned to the
       daemon login class.

     * Although the default /etc/login.conf is a good source of reasonable
       values for most limits, they may not be appropriate for every system.
       Setting a limit too high may open the system up to abuse, while
       setting it too low may put a strain on productivity.

     * Xorg takes a lot of resources and encourages users to run more
       programs simultaneously.

     * Many limits apply to individual processes, not the user as a whole.
       For example, setting openfiles to 50 means that each process the user
       runs may open up to 50 files. The total amount of files a user may
       open is the value of openfiles multiplied by the value of maxproc.
       This also applies to memory consumption.

   For further information on resource limits and login classes and
   capabilities in general, refer to cap_mkdb(1), getrlimit(2), and
   login.conf(5).

  14.13.2. Enabling and Configuring Resource Limits

   The kern.racct.enable tunable must be set to a non-zero value. Custom
   kernels require specific configuration:

 options         RACCT
 options         RCTL

   Once the system has rebooted into the new kernel, rctl may be used to set
   rules for the system.

   Rule syntax is controlled through the use of a subject, subject-id,
   resource, and action, as seen in this example rule:

 user:trhodes:maxproc:deny=10/user

   In this rule, the subject is user, the subject-id is trhodes, the
   resource, maxproc, is the maximum number of processes, and the action is
   deny, which blocks any new processes from being created. This means that
   the user, trhodes, will be constrained to no greater than 10 processes.
   Other possible actions include logging to the console, passing a
   notification to devd(8), or sending a sigterm to the process.

   Some care must be taken when adding rules. Since this user is constrained
   to 10 processes, this example will prevent the user from performing other
   tasks after logging in and executing a screen session. Once a resource
   limit has been hit, an error will be printed, as in this example:

 % man test
     /usr/bin/man: Cannot fork: Resource temporarily unavailable
 eval: Cannot fork: Resource temporarily unavailable

   As another example, a jail can be prevented from exceeding a memory limit.
   This rule could be written as:

 # rctl -a jail:httpd:memoryuse:deny=2G/jail

   Rules will persist across reboots if they have been added to
   /etc/rctl.conf. The format is a rule, without the preceding command. For
   example, the previous rule could be added as:

 # Block jail from using more than 2G memory:
 jail:httpd:memoryuse:deny=2G/jail

   To remove a rule, use rctl to remove it from the list:

 # rctl -r user:trhodes:maxproc:deny=10/user

   A method for removing all rules is documented in rctl(8). However, if
   removing all rules for a single user is required, this command may be
   issued:

 # rctl -r user:trhodes

   Many other resources exist which can be used to exert additional control
   over various subjects. See rctl(8) to learn about them.

14.14. Shared Administration with Sudo

   Contributed by Tom Rhodes.

   System administrators often need the ability to grant enhanced permissions
   to users so they may perform privileged tasks. The idea that team members
   are provided access to a FreeBSD system to perform their specific tasks
   opens up unique challenges to every administrator. These team members only
   need a subset of access beyond normal end user levels; however, they
   almost always tell management they are unable to perform their tasks
   without superuser access. Thankfully, there is no reason to provide such
   access to end users because tools exist to manage this exact requirement.

   Up to this point, the security chapter has covered permitting access to
   authorized users and attempting to prevent unauthorized access. Another
   problem arises once authorized users have access to the system resources.
   In many cases, some users may need access to application startup scripts,
   or a team of administrators need to maintain the system. Traditionally,
   the standard users and groups, file permissions, and even the su(1)
   command would manage this access. And as applications required more
   access, as more users needed to use system resources, a better solution
   was required. The most used application is currently Sudo.

   Sudo allows administrators to configure more rigid access to system
   commands and provide for some advanced logging features. As a tool, it is
   available from the Ports Collection as security/sudo or by use of the
   pkg(8) utility. To use the pkg(8) tool:

 # pkg install sudo

   After the installation is complete, the installed visudo will open the
   configuration file with a text editor. Using visudo is highly recommended
   as it comes with a built in syntax checker to verify there are no errors
   before the file is saved.

   The configuration file is made up of several small sections which allow
   for extensive configuration. In the following example, web application
   maintainer, user1, needs to start, stop, and restart the web application
   known as webservice. To grant this user permission to perform these tasks,
   add this line to the end of /usr/local/etc/sudoers:

 user1   ALL=(ALL)       /usr/sbin/service webservice *

   The user may now start webservice using this command:

 % sudo /usr/sbin/service webservice start

   While this configuration allows a single user access to the webservice
   service; however, in most organizations, there is an entire web team in
   charge of managing the service. A single line can also give access to an
   entire group. These steps will create a web group, add a user to this
   group, and allow all members of the group to manage the service:

 # pw groupadd -g 6001 -n webteam

   Using the same pw(8) command, the user is added to the webteam group:

 # pw groupmod -m user1 -n webteam

   Finally, this line in /usr/local/etc/sudoers allows any member of the
   webteam group to manage webservice:

 %webteam   ALL=(ALL)       /usr/sbin/service webservice *

   Unlike su(1), Sudo only requires the end user password. This adds an
   advantage where users will not need shared passwords, a finding in most
   security audits and just bad all the way around.

   Users permitted to run applications with Sudo only enter their own
   passwords. This is more secure and gives better control than su(1), where
   the root password is entered and the user acquires all root permissions.

  Tip:

   Most organizations are moving or have moved toward a two factor
   authentication model. In these cases, the user may not have a password to
   enter. Sudo provides for these cases with the NOPASSWD variable. Adding it
   to the configuration above will allow all members of the webteam group to
   manage the service without the password requirement:

 %webteam   ALL=(ALL)       NOPASSWD: /usr/sbin/service webservice *

  14.14.1. Logging Output

   An advantage to implementing Sudo is the ability to enable session
   logging. Using the built in log mechanisms and the included sudoreplay
   command, all commands initiated through Sudo are logged for later
   verification. To enable this feature, add a default log directory entry,
   this example uses a user variable. Several other log filename conventions
   exist, consult the manual page for sudoreplay for additional information.

 Defaults iolog_dir=/var/log/sudo-io/%{user}

  Tip:

   This directory will be created automatically after the logging is
   configured. It is best to let the system create directory with default
   permissions just to be safe. In addition, this entry will also log
   administrators who use the sudoreplay command. To change this behavior,
   read and uncomment the logging options inside sudoers.

   Once this directive has been added to the sudoers file, any user
   configuration can be updated with the request to log access. In the
   example shown, the updated webteam entry would have the following
   additional changes:

 %webteam ALL=(ALL) NOPASSWD: LOG_INPUT: LOG_OUTPUT: /usr/sbin/service webservice *

   From this point on, all webteam members altering the status of the
   webservice application will be logged. The list of previous and current
   sessions can be displayed with:

 # sudoreplay -l

   In the output, to replay a specific session, search for the TSID= entry,
   and pass that to sudoreplay with no other options to replay the session at
   normal speed. For example:

 # sudoreplay user1/00/00/02

  Warning:

   While sessions are logged, any administrator is able to remove sessions
   and leave only a question of why they had done so. It is worthwhile to add
   a daily check through an intrusion detection system (IDS) or similar
   software so that other administrators are alerted to manual alterations.

   The sudoreplay is extremely extendable. Consult the documentation for more
   information.

Chapter 15. Jails

   Contributed by Matteo Riondato.
   Table of Contents

   15.1. Synopsis

   15.2. Terms Related to Jails

   15.3. Creating and Controlling Jails

   15.4. Fine Tuning and Administration

   15.5. Updating Multiple Jails

   15.6. Managing Jails with ezjail

15.1. Synopsis

   Since system administration is a difficult task, many tools have been
   developed to make life easier for the administrator. These tools often
   enhance the way systems are installed, configured, and maintained. One of
   the tools which can be used to enhance the security of a FreeBSD system is
   jails. Jails have been available since FreeBSD 4.X and continue to be
   enhanced in their usefulness, performance, reliability, and security.

   Jails build upon the chroot(2) concept, which is used to change the root
   directory of a set of processes. This creates a safe environment, separate
   from the rest of the system. Processes created in the chrooted environment
   can not access files or resources outside of it. For that reason,
   compromising a service running in a chrooted environment should not allow
   the attacker to compromise the entire system. However, a chroot has
   several limitations. It is suited to easy tasks which do not require much
   flexibility or complex, advanced features. Over time, many ways have been
   found to escape from a chrooted environment, making it a less than ideal
   solution for securing services.

   Jails improve on the concept of the traditional chroot environment in
   several ways. In a traditional chroot environment, processes are only
   limited in the part of the file system they can access. The rest of the
   system resources, system users, running processes, and the networking
   subsystem are shared by the chrooted processes and the processes of the
   host system. Jails expand this model by virtualizing access to the file
   system, the set of users, and the networking subsystem. More fine-grained
   controls are available for tuning the access of a jailed environment.
   Jails can be considered as a type of operating system-level
   virtualization.

   A jail is characterized by four elements:

     * A directory subtree: the starting point from which a jail is entered.
       Once inside the jail, a process is not permitted to escape outside of
       this subtree.

     * A hostname: which will be used by the jail.

     * An IP address: which is assigned to the jail. The IP address of a jail
       is often an alias address for an existing network interface.

     * A command: the path name of an executable to run inside the jail. The
       path is relative to the root directory of the jail environment.

   Jails have their own set of users and their own root account which are
   limited to the jail environment. The root account of a jail is not allowed
   to perform operations to the system outside of the associated jail
   environment.

   This chapter provides an overview of the terminology and commands for
   managing FreeBSD jails. Jails are a powerful tool for both system
   administrators, and advanced users.

   After reading this chapter, you will know:

     * What a jail is and what purpose it may serve in FreeBSD installations.

     * How to build, start, and stop a jail.

     * The basics of jail administration, both from inside and outside the
       jail.

  Important:

   Jails are a powerful tool, but they are not a security panacea. While it
   is not possible for a jailed process to break out on its own, there are
   several ways in which an unprivileged user outside the jail can cooperate
   with a privileged user inside the jail to obtain elevated privileges in
   the host environment.

   Most of these attacks can be mitigated by ensuring that the jail root is
   not accessible to unprivileged users in the host environment. As a general
   rule, untrusted users with privileged access to a jail should not be given
   access to the host environment.

15.2. Terms Related to Jails

   To facilitate better understanding of parts of the FreeBSD system related
   to jails, their internals and the way they interact with the rest of
   FreeBSD, the following terms are used further in this chapter:

   chroot(8) (command)

           Utility, which uses chroot(2) FreeBSD system call to change the
           root directory of a process and all its descendants.

   chroot(2) (environment)

           The environment of processes running in a "chroot". This includes
           resources such as the part of the file system which is visible,
           user and group IDs which are available, network interfaces and
           other IPC mechanisms, etc.

   jail(8) (command)

           The system administration utility which allows launching of
           processes within a jail environment.

   host (system, process, user, etc.)

           The controlling system of a jail environment. The host system has
           access to all the hardware resources available, and can control
           processes both outside of and inside a jail environment. One of
           the important differences of the host system from a jail is that
           the limitations which apply to superuser processes inside a jail
           are not enforced for processes of the host system.

   hosted (system, process, user, etc.)

           A process, user or other entity, whose access to resources is
           restricted by a FreeBSD jail.

15.3. Creating and Controlling Jails

   Some administrators divide jails into the following two types: "complete"
   jails, which resemble a real FreeBSD system, and "service" jails,
   dedicated to one application or service, possibly running with privileges.
   This is only a conceptual division and the process of building a jail is
   not affected by it. When creating a "complete" jail there are two options
   for the source of the userland: use prebuilt binaries (such as those
   supplied on an install media) or build from source.

  15.3.1. Installing a Jail

    15.3.1.1. To install a Jail from the Internet

   The bsdinstall(8) tool can be used to fetch and install the binaries
   needed for a jail. This will walk through the picking of a mirror, which
   distributions will be installed into the destination directory, and some
   basic configuration of the jail:

 # bsdinstall jail /here/is/the/jail

   Once the command is complete, the next step is configuring the host to run
   the jail.

    15.3.1.2. To install a Jail from an ISO

   To install the userland from installation media, first create the root
   directory for the jail. This can be done by setting the DESTDIR variable
   to the proper location.

   Start a shell and define DESTDIR:

 # sh
 # export DESTDIR=/here/is/the/jail

   Mount the install media as covered in mdconfig(8) when using the install
   ISO:

 # mount -t cd9660 /dev/`mdconfig -f cdimage.iso` /mnt
 # cd /mnt/usr/freebsd-dist/

   Extract the binaries from the tarballs on the install media into the
   declared destination. Minimally, only the base set needs to be extracted,
   but a complete install can be performed when preferred.

   To install just the base system:

 # tar -xf base.txz -C $DESTDIR

   To install everything except the kernel:

 # for set in base ports; do tar -xf $set.txz -C $DESTDIR ; done

    15.3.1.3. To build and install a Jail from source

   The jail(8) manual page explains the procedure for building a jail:

 # setenv D /here/is/the/jail
 # mkdir -p $D      1
 # cd /usr/src
 # make buildworld  2
 # make installworld DESTDIR=$D  3
 # make distribution DESTDIR=$D  4
 # mount -t devfs devfs $D/dev   5

   1 Selecting a location for a jail is the best starting point. This is      
     where the jail will physically reside within the file system of the      
     jail's host. A good choice can be /usr/jail/jailname, where jailname is  
     the hostname identifying the jail. Usually, /usr/ has enough space for   
     the jail file system, which for "complete" jails is, essentially, a      
     replication of every file present in a default installation of the       
     FreeBSD base system.                                                     
   2 If you have already rebuilt your userland using make world or make       
     buildworld, you can skip this step and install your existing userland    
     into the new jail.                                                       
   3 This command will populate the directory subtree chosen as jail's        
     physical location on the file system with the necessary binaries,        
     libraries, manual pages and so on.                                       
   4 The distribution target for make installs every needed configuration     
     file. In simple words, it installs every installable file of             
     /usr/src/etc/ to the /etc directory of the jail environment: $D/etc/.    
   5 Mounting the devfs(8) file system inside a jail is not required. On the  
     other hand, any, or almost any application requires access to at least   
     one device, depending on the purpose of the given application. It is     
     very important to control access to devices from inside a jail, as       
     improper settings could permit an attacker to do nasty things in the     
     jail. Control over devfs(8) is managed through rulesets which are        
     described in the devfs(8) and devfs.conf(5) manual pages.                

  15.3.2. Configuring the Host

   Once a jail is installed, it can be started by using the jail(8) utility.
   The jail(8) utility takes four mandatory arguments which are described in
   the Section 15.1, "Synopsis". Other arguments may be specified too, e.g.,
   to run the jailed process with the credentials of a specific user. The
   command argument depends on the type of the jail; for a virtual system,
   /etc/rc is a good choice, since it will replicate the startup sequence of
   a real FreeBSD system. For a service jail, it depends on the service or
   application that will run within the jail.

   Jails are often started at boot time and the FreeBSD rc mechanism provides
   an easy way to do this.

     * Configure jail parameters in jail.conf:

 www {
     host.hostname = www.example.org;           # Hostname
     ip4.addr = 192.168.0.10;                   # IP address of the jail
     path = "/usr/jail/www";                    # Path to the jail
     devfs_ruleset = "www_ruleset";             # devfs ruleset
     mount.devfs;                               # Mount devfs inside the jail
     exec.start = "/bin/sh /etc/rc";            # Start command
     exec.stop = "/bin/sh /etc/rc.shutdown";    # Stop command
 }

       Configure jails to start at boot time in rc.conf:

 jail_enable="YES"   # Set to NO to disable starting of any jails

       The default startup of jails configured in jail.conf(5), will run the
       /etc/rc script of the jail, which assumes the jail is a complete
       virtual system. For service jails, the default startup command of the
       jail should be changed, by setting the exec.start option
       appropriately.

  Note:

       For a full list of available options, please see the jail.conf(5)
       manual page.

   service(8) can be used to start or stop a jail by hand, if an entry for it
   exists in jail.conf:

 # service jail start www
 # service jail stop www

   Jails can be shut down with jexec(8). Use jls(8) to identify the jail's
   JID, then use jexec(8) to run the shutdown script in that jail.

 # jls
    JID  IP Address      Hostname                      Path
      3  192.168.0.10    www                           /usr/jail/www
 # jexec 3 /etc/rc.shutdown

   More information about this can be found in the jail(8) manual page.

15.4. Fine Tuning and Administration

   There are several options which can be set for any jail, and various ways
   of combining a host FreeBSD system with jails, to produce higher level
   applications. This section presents:

     * Some of the options available for tuning the behavior and security
       restrictions implemented by a jail installation.

     * Some of the high-level applications for jail management, which are
       available through the FreeBSD Ports Collection, and can be used to
       implement overall jail-based solutions.

  15.4.1. System Tools for Jail Tuning in FreeBSD

   Fine tuning of a jail's configuration is mostly done by setting sysctl(8)
   variables. A special subtree of sysctl exists as a basis for organizing
   all the relevant options: the security.jail.* hierarchy of FreeBSD kernel
   options. Here is a list of the main jail-related sysctls, complete with
   their default value. Names should be self-explanatory, but for more
   information about them, please refer to the jail(8) and sysctl(8) manual
   pages.

     * security.jail.set_hostname_allowed: 1

     * security.jail.socket_unixiproute_only: 1

     * security.jail.sysvipc_allowed: 0

     * security.jail.enforce_statfs: 2

     * security.jail.allow_raw_sockets: 0

     * security.jail.chflags_allowed: 0

     * security.jail.jailed: 0

   These variables can be used by the system administrator of the host system
   to add or remove some of the limitations imposed by default on the root
   user. Note that there are some limitations which cannot be removed. The
   root user is not allowed to mount or unmount file systems from within a
   jail(8). The root inside a jail may not load or unload devfs(8) rulesets,
   set firewall rules, or do many other administrative tasks which require
   modifications of in-kernel data, such as setting the securelevel of the
   kernel.

   The base system of FreeBSD contains a basic set of tools for viewing
   information about the active jails, and attaching to a jail to run
   administrative commands. The jls(8) and jexec(8) commands are part of the
   base FreeBSD system, and can be used to perform the following simple
   tasks:

     * Print a list of active jails and their corresponding jail identifier
       (JID), IP address, hostname and path.

     * Attach to a running jail, from its host system, and run a command
       inside the jail or perform administrative tasks inside the jail
       itself. This is especially useful when the root user wants to cleanly
       shut down a jail. The jexec(8) utility can also be used to start a
       shell in a jail to do administration in it; for example:

 # jexec 1 tcsh

  15.4.2. High-Level Administrative Tools in the FreeBSD Ports Collection

   Among the many third-party utilities for jail administration, one of the
   most complete and useful is sysutils/ezjail. It is a set of scripts that
   contribute to jail(8) management. Please refer to the handbook section on
   ezjail for more information.

  15.4.3. Keeping Jails Patched and up to Date

   Jails should be kept up to date from the host operating system as
   attempting to patch userland from within the jail may likely fail as the
   default behavior in FreeBSD is to disallow the use of chflags(1) in a jail
   which prevents the replacement of some files. It is possible to change
   this behavior but it is recommended to use freebsd-update(8) to maintain
   jails instead. Use -b to specify the path of the jail to be updated.

   To update the jail to the latest patch release of the version of FreeBSD
   it is already running, then execute the following commands on the host:

 # freebsd-update -b /here/is/the/jail fetch
 # freebsd-update -b /here/is/the/jail install

   To upgrade the jail to a new major or minor version, first upgrade the
   host system as described in Section 24.2.3, "Performing Major and Minor
   Version Upgrades". Once the host has been upgraded and rebooted, the jail
   can then be upgraded. For example to upgrade from 12.0-RELEASE to
   12.1-RELEASE, on the host run:

 # freebsd-update -b /here/is/the/jail --currently-running 12.0-RELEASE -r 12.1-RELEASE upgrade
 # freebsd-update -b /here/is/the/jail install
 # service jail restart myjail
 # freebsd-update -b /here/is/the/jail install

   Then, if it was a major version upgrade, reinstall all installed packages
   and restart the jail again. This is required because the ABI version
   changes when upgrading between major versions of FreeBSD. From the host:

 # pkg -j myjail upgrade -f
 # service jail restart myjail

15.5. Updating Multiple Jails

   Contributed by Daniel Gerzo.
   Based upon an idea presented by Simon L. B. Nielsen.
   And an article written by Ken Tom.

   The management of multiple jails can become problematic because every jail
   has to be rebuilt from scratch whenever it is upgraded. This can be time
   consuming and tedious if a lot of jails are created and manually updated.

   This section demonstrates one method to resolve this issue by safely
   sharing as much as is possible between jails using read-only
   mount_nullfs(8) mounts, so that updating is simpler. This makes it more
   attractive to put single services, such as HTTP, DNS, and SMTP, into
   individual jails. Additionally, it provides a simple way to add, remove,
   and upgrade jails.

  Note:

   Simpler solutions exist, such as ezjail, which provides an easier method
   of administering FreeBSD jails but is less versatile than this setup.
   ezjail is covered in more detail in Section 15.6, "Managing Jails with
   ezjail".

   The goals of the setup described in this section are:

     * Create a simple and easy to understand jail structure that does not
       require running a full installworld on each and every jail.

     * Make it easy to add new jails or remove existing ones.

     * Make it easy to update or upgrade existing jails.

     * Make it possible to run a customized FreeBSD branch.

     * Be paranoid about security, reducing as much as possible the
       possibility of compromise.

     * Save space and inodes, as much as possible.

   This design relies on a single, read-only master template which is mounted
   into each jail and one read-write device per jail. A device can be a
   separate physical disc, a partition, or a vnode backed memory device. This
   example uses read-write nullfs mounts.

   The file system layout is as follows:

     * The jails are based under the /home partition.

     * Each jail will be mounted under the /home/j directory.

     * The template for each jail and the read-only partition for all of the
       jails is /home/j/mroot.

     * A blank directory will be created for each jail under the /home/j
       directory.

     * Each jail will have a /s directory that will be linked to the
       read-write portion of the system.

     * Each jail will have its own read-write system that is based upon
       /home/j/skel.

     * The read-write portion of each jail will be created in /home/js.

  15.5.1. Creating the Template

   This section describes the steps needed to create the master template.

   It is recommended to first update the host FreeBSD system to the latest
   -RELEASE branch using the instructions in Section 24.5, "Updating FreeBSD
   from Source". Additionally, this template uses the sysutils/cpdup package
   or port and portsnap will be used to download the FreeBSD Ports
   Collection.

    1. First, create a directory structure for the read-only file system
       which will contain the FreeBSD binaries for the jails. Then, change
       directory to the FreeBSD source tree and install the read-only file
       system to the jail template:

 # mkdir /home/j /home/j/mroot
 # cd /usr/src
 # make installworld DESTDIR=/home/j/mroot

    2. Next, prepare a FreeBSD Ports Collection for the jails as well as a
       FreeBSD source tree, which is required for mergemaster:

 # cd /home/j/mroot
 # mkdir usr/ports
 # portsnap -p /home/j/mroot/usr/ports fetch extract
 # cpdup /usr/src /home/j/mroot/usr/src

    3. Create a skeleton for the read-write portion of the system:

 # mkdir /home/j/skel /home/j/skel/home /home/j/skel/usr-X11R6 /home/j/skel/distfiles
 # mv etc /home/j/skel
 # mv usr/local /home/j/skel/usr-local
 # mv tmp /home/j/skel
 # mv var /home/j/skel
 # mv root /home/j/skel

    4. Use mergemaster to install missing configuration files. Then, remove
       the extra directories that mergemaster creates:

 # mergemaster -t /home/j/skel/var/tmp/temproot -D /home/j/skel -i
 # cd /home/j/skel
 # rm -R bin boot lib libexec mnt proc rescue sbin sys usr dev

    5. Now, symlink the read-write file system to the read-only file system.
       Ensure that the symlinks are created in the correct s/ locations as
       the creation of directories in the wrong locations will cause the
       installation to fail.

 # cd /home/j/mroot
 # mkdir s
 # ln -s s/etc etc
 # ln -s s/home home
 # ln -s s/root root
 # ln -s ../s/usr-local usr/local
 # ln -s ../s/usr-X11R6 usr/X11R6
 # ln -s ../../s/distfiles usr/ports/distfiles
 # ln -s s/tmp tmp
 # ln -s s/var var

    6. As a last step, create a generic /home/j/skel/etc/make.conf containing
       this line:

 WRKDIRPREFIX?=  /s/portbuild

       This makes it possible to compile FreeBSD ports inside each jail.
       Remember that the ports directory is part of the read-only system. The
       custom path for WRKDIRPREFIX allows builds to be done in the
       read-write portion of every jail.

  15.5.2. Creating Jails

   The jail template can now be used to setup and configure the jails in
   /etc/rc.conf. This example demonstrates the creation of 3 jails: NS, MAIL
   and WWW.

    1. Add the following lines to /etc/fstab, so that the read-only template
       for the jails and the read-write space will be available in the
       respective jails:

 /home/j/mroot   /home/j/ns     nullfs  ro  0   0
 /home/j/mroot   /home/j/mail   nullfs  ro  0   0
 /home/j/mroot   /home/j/www    nullfs  ro  0   0
 /home/js/ns     /home/j/ns/s   nullfs  rw  0   0
 /home/js/mail   /home/j/mail/s nullfs  rw  0   0
 /home/js/www    /home/j/www/s  nullfs  rw  0   0

       To prevent fsck from checking nullfs mounts during boot and dump from
       backing up the read-only nullfs mounts of the jails, the last two
       columns are both set to 0.

    2. Configure the jails in /etc/rc.conf:

 jail_enable="YES"
 jail_set_hostname_allow="NO"
 jail_list="ns mail www"
 jail_ns_hostname="ns.example.org"
 jail_ns_ip="192.168.3.17"
 jail_ns_rootdir="/usr/home/j/ns"
 jail_ns_devfs_enable="YES"
 jail_mail_hostname="mail.example.org"
 jail_mail_ip="192.168.3.18"
 jail_mail_rootdir="/usr/home/j/mail"
 jail_mail_devfs_enable="YES"
 jail_www_hostname="www.example.org"
 jail_www_ip="62.123.43.14"
 jail_www_rootdir="/usr/home/j/www"
 jail_www_devfs_enable="YES"

       The jail_name_rootdir variable is set to /usr/home instead of /home
       because the physical path of /home on a default FreeBSD installation
       is /usr/home. The jail_name_rootdir variable must not be set to a path
       which includes a symbolic link, otherwise the jails will refuse to
       start.

    3. Create the required mount points for the read-only file system of each
       jail:

 # mkdir /home/j/ns /home/j/mail /home/j/www

    4. Install the read-write template into each jail using sysutils/cpdup:

 # mkdir /home/js
 # cpdup /home/j/skel /home/js/ns
 # cpdup /home/j/skel /home/js/mail
 # cpdup /home/j/skel /home/js/www

    5. In this phase, the jails are built and prepared to run. First, mount
       the required file systems for each jail, and then start them:

 # mount -a
 # service jail start

   The jails should be running now. To check if they have started correctly,
   use jls. Its output should be similar to the following:

 # jls
    JID  IP Address      Hostname                      Path
      3  192.168.3.17    ns.example.org                /home/j/ns
      2  192.168.3.18    mail.example.org              /home/j/mail
      1  62.123.43.14    www.example.org               /home/j/www

   At this point, it should be possible to log onto each jail, add new users,
   or configure daemons. The JID column indicates the jail identification
   number of each running jail. Use the following command to perform
   administrative tasks in the jail whose JID is 3:

 # jexec 3 tcsh

  15.5.3. Upgrading

   The design of this setup provides an easy way to upgrade existing jails
   while minimizing their downtime. Also, it provides a way to roll back to
   the older version should a problem occur.

    1. The first step is to upgrade the host system. Then, create a new
       temporary read-only template in /home/j/mroot2.

 # mkdir /home/j/mroot2
 # cd /usr/src
 # make installworld DESTDIR=/home/j/mroot2
 # cd /home/j/mroot2
 # cpdup /usr/src usr/src
 # mkdir s

       The installworld creates a few unnecessary directories, which should
       be removed:

 # chflags -R 0 var
 # rm -R etc var root usr/local tmp

    2. Recreate the read-write symlinks for the master file system:

 # ln -s s/etc etc
 # ln -s s/root root
 # ln -s s/home home
 # ln -s ../s/usr-local usr/local
 # ln -s ../s/usr-X11R6 usr/X11R6
 # ln -s s/tmp tmp
 # ln -s s/var var

    3. Next, stop the jails:

 # service jail stop

    4. Unmount the original file systems as the read-write systems are
       attached to the read-only system (/s):

 # umount /home/j/ns/s
 # umount /home/j/ns
 # umount /home/j/mail/s
 # umount /home/j/mail
 # umount /home/j/www/s
 # umount /home/j/www

    5. Move the old read-only file system and replace it with the new one.
       This will serve as a backup and archive of the old read-only file
       system should something go wrong. The naming convention used here
       corresponds to when a new read-only file system has been created. Move
       the original FreeBSD Ports Collection over to the new file system to
       save some space and inodes:

 # cd /home/j
 # mv mroot mroot.20060601
 # mv mroot2 mroot
 # mv mroot.20060601/usr/ports mroot/usr

    6. At this point the new read-only template is ready, so the only
       remaining task is to remount the file systems and start the jails:

 # mount -a
 # service jail start

   Use jls to check if the jails started correctly. Run mergemaster in each
   jail to update the configuration files.

15.6. Managing Jails with ezjail

   Originally contributed by Warren Block.

   Creating and managing multiple jails can quickly become tedious and
   error-prone. Dirk Engling's ezjail automates and greatly simplifies many
   jail tasks. A basejail is created as a template. Additional jails use
   mount_nullfs(8) to share many of the basejail directories without using
   additional disk space. Each additional jail takes only a few megabytes of
   disk space before applications are installed. Upgrading the copy of the
   userland in the basejail automatically upgrades all of the other jails.

   Additional benefits and features are described in detail on the ezjail web
   site, https://erdgeist.org/arts/software/ezjail/.

  15.6.1. Installing ezjail

   Installing ezjail consists of adding a loopback interface for use in
   jails, installing the port or package, and enabling the service.

    1. To keep jail loopback traffic off the host's loopback network
       interface lo0, a second loopback interface is created by adding an
       entry to /etc/rc.conf:

 cloned_interfaces="lo1"

       The second loopback interface lo1 will be created when the system
       starts. It can also be created manually without a restart:

 # service netif cloneup
 Created clone interfaces: lo1.

       Jails can be allowed to use aliases of this secondary loopback
       interface without interfering with the host.

       Inside a jail, access to the loopback address 127.0.0.1 is redirected
       to the first IP address assigned to the jail. To make the jail
       loopback correspond with the new lo1 interface, that interface must be
       specified first in the list of interfaces and IP addresses given when
       creating a new jail.

       Give each jail a unique loopback address in the 127.0.0.0/8 netblock.

    2. Install sysutils/ezjail:

 # cd /usr/ports/sysutils/ezjail
 # make install clean

    3. Enable ezjail by adding this line to /etc/rc.conf:

 ezjail_enable="YES"

    4. The service will automatically start on system boot. It can be started
       immediately for the current session:

 # service ezjail start

  15.6.2. Initial Setup

   With ezjail installed, the basejail directory structure can be created and
   populated. This step is only needed once on the jail host computer.

   In both of these examples, -p causes the ports tree to be retrieved with
   portsnap(8) into the basejail. That single copy of the ports directory
   will be shared by all the jails. Using a separate copy of the ports
   directory for jails isolates them from the host. The ezjail FAQ explains
   in more detail: http://erdgeist.org/arts/software/ezjail/#FAQ.

     *    * To Populate the Jail with FreeBSD-RELEASE

            For a basejail based on the FreeBSD RELEASE matching that of the
            host computer, use install. For example, on a host computer
            running FreeBSD 10-STABLE, the latest RELEASE version of
            FreeBSD -10 will be installed in the jail):

 # ezjail-admin install -p

          * To Populate the Jail with installworld

            The basejail can be installed from binaries created by buildworld
            on the host with ezjail-admin update.

            In this example, FreeBSD 10-STABLE has been built from source.
            The jail directories are created. Then installworld is executed,
            installing the host's /usr/obj into the basejail.

 # ezjail-admin update -i -p

            The host's /usr/src is used by default. A different source
            directory on the host can be specified with -s and a path, or set
            with ezjail_sourcetree in /usr/local/etc/ezjail.conf.

  Tip:

   The basejail's ports tree is shared by other jails. However, downloaded
   distfiles are stored in the jail that downloaded them. By default, these
   files are stored in /var/ports/distfiles within each jail. /var/ports
   inside each jail is also used as a work directory when building ports.

  Tip:

   The FTP protocol is used by default to download packages for the
   installation of the basejail. Firewall or proxy configurations can prevent
   or interfere with FTP transfers. The HTTP protocol works differently and
   avoids these problems. It can be chosen by specifying a full URL for a
   particular download mirror in /usr/local/etc/ezjail.conf:

 ezjail_ftphost=http://ftp.FreeBSD.org

   See Section A.2, "FTP Sites" for a list of sites.

  15.6.3. Creating and Starting a New Jail

   New jails are created with ezjail-admin create. In these examples, the lo1
   loopback interface is used as described above.

   Procedure 15.1. Create and Start a New Jail
    1. Create the jail, specifying a name and the loopback and network
       interfaces to use, along with their IP addresses. In this example, the
       jail is named dnsjail.

 # ezjail-admin create dnsjail 'lo1|127.0.1.1,em0|192.168.1.50'

  Tip:

       Most network services run in jails without problems. A few network
       services, most notably ping(8), use raw network sockets. In jails, raw
       network sockets are disabled by default for security. Services that
       require them will not work.

       Occasionally, a jail genuinely needs raw sockets. For example, network
       monitoring applications often use ping(8) to check the availability of
       other computers. When raw network sockets are actually needed in a
       jail, they can be enabled by editing the ezjail configuration file for
       the individual jail, /usr/local/etc/ezjail/jailname. Modify the
       parameters entry:

 export jail_jailname_parameters="allow.raw_sockets=1"

       Do not enable raw network sockets unless services in the jail actually
       require them.

    2. Start the jail:

 # ezjail-admin start dnsjail

    3. Use a console on the jail:

 # ezjail-admin console dnsjail

   The jail is operating and additional configuration can be completed.
   Typical settings added at this point include:

    1. Set the root Password

       Connect to the jail and set the root user's password:

 # ezjail-admin console dnsjail
 # passwd
 Changing local password for root
 New Password:
 Retype New Password:

    2. Time Zone Configuration

       The jail's time zone can be set with tzsetup(8). To avoid spurious
       error messages, the adjkerntz(8) entry in /etc/crontab can be
       commented or removed. This job attempts to update the computer's
       hardware clock with time zone changes, but jails are not allowed to
       access that hardware.

    3. DNS Servers

       Enter domain name server lines in /etc/resolv.conf so DNS works in the
       jail.

    4. Edit /etc/hosts

       Change the address and add the jail name to the localhost entries in
       /etc/hosts.

    5. Configure /etc/rc.conf

       Enter configuration settings in /etc/rc.conf. This is much like
       configuring a full computer. The host name and IP address are not set
       here. Those values are already provided by the jail configuration.

   With the jail configured, the applications for which the jail was created
   can be installed.

  Tip:

   Some ports must be built with special options to be used in a jail. For
   example, both of the network monitoring plugin packages
   net-mgmt/nagios-plugins and net-mgmt/monitoring-plugins have a JAIL option
   which must be enabled for them to work correctly inside a jail.

  15.6.4. Updating Jails

    15.6.4.1. Updating the Operating System

   Because the basejail's copy of the userland is shared by the other jails,
   updating the basejail automatically updates all of the other jails. Either
   source or binary updates can be used.

   To build the world from source on the host, then install it in the
   basejail, use:

 # ezjail-admin update -b

   If the world has already been compiled on the host, install it in the
   basejail with:

 # ezjail-admin update -i

   Binary updates use freebsd-update(8). These updates have the same
   limitations as if freebsd-update(8) were being run directly. The most
   important one is that only -RELEASE versions of FreeBSD are available with
   this method.

   Update the basejail to the latest patched release of the version of
   FreeBSD on the host. For example, updating from RELEASE-p1 to RELEASE-p2.

 # ezjail-admin update -u

   To upgrade the basejail to a new version, first upgrade the host system as
   described in Section 24.2.3, "Performing Major and Minor Version
   Upgrades". Once the host has been upgraded and rebooted, the basejail can
   then be upgraded. freebsd-update(8) has no way of determining which
   version is currently installed in the basejail, so the original version
   must be specified. Use file(1) to determine the original version in the
   basejail:

 # file /usr/jails/basejail/bin/sh
 /usr/jails/basejail/bin/sh: ELF 64-bit LSB executable, x86-64, version 1 (FreeBSD), dynamically linked (uses shared libs), for FreeBSD 9.3, stripped

   Now use this information to perform the upgrade from 9.3-RELEASE to the
   current version of the host system:

 # ezjail-admin update -U -s 9.3-RELEASE

   After updating the basejail, mergemaster(8) must be run to update each
   jail's configuration files.

   How to use mergemaster(8) depends on the purpose and trustworthiness of a
   jail. If a jail's services or users are not trusted, then mergemaster(8)
   should only be run from within that jail:

   Example 15.1. mergemaster(8) on Untrusted Jail

   Delete the link from the jail's /usr/src into the basejail and create a
   new /usr/src in the jail as a mountpoint. Mount the host computer's
   /usr/src read-only on the jail's new /usr/src mountpoint:

 # rm /usr/jails/jailname/usr/src
 # mkdir /usr/jails/jailname/usr/src
 # mount -t nullfs -o ro /usr/src /usr/jails/jailname/usr/src

   Get a console in the jail:

 # ezjail-admin console jailname

   Inside the jail, run mergemaster. Then exit the jail console:

 # cd /usr/src
 # mergemaster -U
 # exit

   Finally, unmount the jail's /usr/src:

 # umount /usr/jails/jailname/usr/src

   Example 15.2. mergemaster(8) on Trusted Jail

   If the users and services in a jail are trusted, mergemaster(8) can be run
   from the host:

 # mergemaster -U -D /usr/jails/jailname

  Tip:

   After a major version update it is recommended by sysutils/ezjail to make
   sure your pkg is of the correct version. Therefore enter:

 # pkg-static upgrade -f pkg

   to upgrade or downgrade to the appropriate version.

    15.6.4.2. Updating Ports

   The ports tree in the basejail is shared by the other jails. Updating that
   copy of the ports tree gives the other jails the updated version also.

   The basejail ports tree is updated with portsnap(8):

 # ezjail-admin update -P

  15.6.5. Controlling Jails

    15.6.5.1. Stopping and Starting Jails

   ezjail automatically starts jails when the computer is started. Jails can
   be manually stopped and restarted with stop and start:

 # ezjail-admin stop sambajail
 Stopping jails: sambajail.

   By default, jails are started automatically when the host computer starts.
   Autostarting can be disabled with config:

 # ezjail-admin config -r norun seldomjail

   This takes effect the next time the host computer is started. A jail that
   is already running will not be stopped.

   Enabling autostart is very similar:

 # ezjail-admin config -r run oftenjail

    15.6.5.2. Archiving and Restoring Jails

   Use archive to create a .tar.gz archive of a jail. The file name is
   composed from the name of the jail and the current date. Archive files are
   written to the archive directory, /usr/jails/ezjail_archives. A different
   archive directory can be chosen by setting ezjail_archivedir in the
   configuration file.

   The archive file can be copied elsewhere as a backup, or an existing jail
   can be restored from it with restore. A new jail can be created from the
   archive, providing a convenient way to clone existing jails.

   Stop and archive a jail named wwwserver:

 # ezjail-admin stop wwwserver
 Stopping jails: wwwserver.
 # ezjail-admin archive wwwserver
 # ls /usr/jails/ezjail-archives/
 wwwserver-201407271153.13.tar.gz

   Create a new jail named wwwserver-clone from the archive created in the
   previous step. Use the em1 interface and assign a new IP address to avoid
   conflict with the original:

 # ezjail-admin create -a /usr/jails/ezjail_archives/wwwserver-201407271153.13.tar.gz wwwserver-clone 'lo1|127.0.3.1,em1|192.168.1.51'

  15.6.6. Full Example: BIND in a Jail

   Putting the BIND DNS server in a jail improves security by isolating it.
   This example creates a simple caching-only name server.

     * The jail will be called dns1.

     * The jail will use IP address 192.168.1.240 on the host's re0
       interface.

     * The upstream ISP's DNS servers are at 10.0.0.62 and 10.0.0.61.

     * The basejail has already been created and a ports tree installed as
       shown in Section 15.6.2, "Initial Setup".

   Example 15.3. Running BIND in a Jail

   Create a cloned loopback interface by adding a line to /etc/rc.conf:

 cloned_interfaces="lo1"

   Immediately create the new loopback interface:

 # service netif cloneup
 Created clone interfaces: lo1.

   Create the jail:

 # ezjail-admin create dns1 'lo1|127.0.2.1,re0|192.168.1.240'

   Start the jail, connect to a console running on it, and perform some basic
   configuration:

 # ezjail-admin start dns1
 # ezjail-admin console dns1
 # passwd
 Changing local password for root
 New Password:
 Retype New Password:
 # tzsetup
 # sed -i .bak -e '/adjkerntz/ s/^/#/' /etc/crontab
 # sed -i .bak -e 's/127.0.0.1/127.0.2.1/g; s/localhost.my.domain/dns1.my.domain dns1/' /etc/hosts

   Temporarily set the upstream DNS servers in /etc/resolv.conf so ports can
   be downloaded:

 nameserver 10.0.0.62
 nameserver 10.0.0.61

   Still using the jail console, install dns/bind99.

 # make -C /usr/ports/dns/bind99 install clean

   Configure the name server by editing /usr/local/etc/namedb/named.conf.

   Create an Access Control List (ACL) of addresses and networks that are
   permitted to send DNS queries to this name server. This section is added
   just before the options section already in the file:

 ...
 // or cause huge amounts of useless Internet traffic.

 acl "trusted" {
         192.168.1.0/24;
         localhost;
         localnets;
 };

 options {
 ...

   Use the jail IP address in the listen-on setting to accept DNS queries
   from other computers on the network:

         listen-on       { 192.168.1.240; };

   A simple caching-only DNS name server is created by changing the
   forwarders section. The original file contains:

 /*
         forwarders {
                 127.0.0.1;
         };
 */

   Uncomment the section by removing the /* and */ lines. Enter the IP
   addresses of the upstream DNS servers. Immediately after the forwarders
   section, add references to the trusted ACL defined earlier:

         forwarders {
                 10.0.0.62;
                 10.0.0.61;
         };

         allow-query       { any; };
         allow-recursion   { trusted; };
         allow-query-cache { trusted; };

   Enable the service in /etc/rc.conf:

 named_enable="YES"

   Start and test the name server:

 # service named start
 wrote key file "/usr/local/etc/namedb/rndc.key"
 Starting named.
 # /usr/local/bin/dig @192.168.1.240 freebsd.org

   A response that includes

 ;; Got answer;

   shows that the new DNS server is working. A long delay followed by a
   response including

 ;; connection timed out; no servers could be reached

   shows a problem. Check the configuration settings and make sure any local
   firewalls allow the new DNS access to the upstream DNS servers.

   The new DNS server can use itself for local name resolution, just like
   other local computers. Set the address of the DNS server in the client
   computer's /etc/resolv.conf:

 nameserver 192.168.1.240

   A local DHCP server can be configured to provide this address for a local
   DNS server, providing automatic configuration on DHCP clients.

Chapter 16. Mandatory Access Control

   Written by Tom Rhodes.
   Table of Contents

   16.1. Synopsis

   16.2. Key Terms

   16.3. Understanding MAC Labels

   16.4. Planning the Security Configuration

   16.5. Available MAC Policies

   16.6. User Lock Down

   16.7. Nagios in a MAC Jail

   16.8. Troubleshooting the MAC Framework

16.1. Synopsis

   FreeBSD supports security extensions based on the POSIX(R).1e draft. These
   security mechanisms include file system Access Control Lists
   (Section 14.9, "Access Control Lists") and Mandatory Access Control (MAC).
   MAC allows access control modules to be loaded in order to implement
   security policies. Some modules provide protections for a narrow subset of
   the system, hardening a particular service. Others provide comprehensive
   labeled security across all subjects and objects. The mandatory part of
   the definition indicates that enforcement of controls is performed by
   administrators and the operating system. This is in contrast to the
   default security mechanism of Discretionary Access Control (DAC) where
   enforcement is left to the discretion of users.

   This chapter focuses on the MAC framework and the set of pluggable
   security policy modules FreeBSD provides for enabling various security
   mechanisms.

   After reading this chapter, you will know:

     * The terminology associated with the MAC framework.

     * The capabilities of MAC security policy modules as well as the
       difference between a labeled and non-labeled policy.

     * The considerations to take into account before configuring a system to
       use the MAC framework.

     * Which MAC security policy modules are included in FreeBSD and how to
       configure them.

     * How to implement a more secure environment using the MAC framework.

     * How to test the MAC configuration to ensure the framework has been
       properly implemented.

   Before reading this chapter, you should:

     * Understand UNIX(R) and FreeBSD basics (Chapter 3, FreeBSD Basics).

     * Have some familiarity with security and how it pertains to FreeBSD
       (Chapter 14, Security).

  Warning:

   Improper MAC configuration may cause loss of system access, aggravation of
   users, or inability to access the features provided by Xorg. More
   importantly, MAC should not be relied upon to completely secure a system.
   The MAC framework only augments an existing security policy. Without sound
   security practices and regular security checks, the system will never be
   completely secure.

   The examples contained within this chapter are for demonstration purposes
   and the example settings should not be implemented on a production system.
   Implementing any security policy takes a good deal of understanding,
   proper design, and thorough testing.

   While this chapter covers a broad range of security issues relating to the
   MAC framework, the development of new MAC security policy modules will not
   be covered. A number of security policy modules included with the MAC
   framework have specific characteristics which are provided for both
   testing and new module development. Refer to mac_test(4), mac_stub(4) and
   mac_none(4) for more information on these security policy modules and the
   various mechanisms they provide.

16.2. Key Terms

   The following key terms are used when referring to the MAC framework:

     * compartment: a set of programs and data to be partitioned or
       separated, where users are given explicit access to specific component
       of a system. A compartment represents a grouping, such as a work
       group, department, project, or topic. Compartments make it possible to
       implement a need-to-know-basis security policy.

     * integrity: the level of trust which can be placed on data. As the
       integrity of the data is elevated, so does the ability to trust that
       data.

     * level: the increased or decreased setting of a security attribute. As
       the level increases, its security is considered to elevate as well.

     * label: a security attribute which can be applied to files,
       directories, or other items in the system. It could be considered a
       confidentiality stamp. When a label is placed on a file, it describes
       the security properties of that file and will only permit access by
       files, users, and resources with a similar security setting. The
       meaning and interpretation of label values depends on the policy
       configuration. Some policies treat a label as representing the
       integrity or secrecy of an object while other policies might use
       labels to hold rules for access.

     * multilabel: this property is a file system option which can be set in
       single-user mode using tunefs(8), during boot using fstab(5), or
       during the creation of a new file system. This option permits an
       administrator to apply different MAC labels on different objects. This
       option only applies to security policy modules which support labeling.

     * single label: a policy where the entire file system uses one label to
       enforce access control over the flow of data. Whenever multilabel is
       not set, all files will conform to the same label setting.

     * object: an entity through which information flows under the direction
       of a subject. This includes directories, files, fields, screens,
       keyboards, memory, magnetic storage, printers or any other data
       storage or moving device. An object is a data container or a system
       resource. Access to an object effectively means access to its data.

     * subject: any active entity that causes information to flow between
       objects such as a user, user process, or system process. On FreeBSD,
       this is almost always a thread acting in a process on behalf of a
       user.

     * policy: a collection of rules which defines how objectives are to be
       achieved. A policy usually documents how certain items are to be
       handled. This chapter considers a policy to be a collection of rules
       which controls the flow of data and information and defines who has
       access to that data and information.

     * high-watermark: this type of policy permits the raising of security
       levels for the purpose of accessing higher level information. In most
       cases, the original level is restored after the process is complete.
       Currently, the FreeBSD MAC framework does not include this type of
       policy.

     * low-watermark: this type of policy permits lowering security levels
       for the purpose of accessing information which is less secure. In most
       cases, the original security level of the user is restored after the
       process is complete. The only security policy module in FreeBSD to use
       this is mac_lomac(4).

     * sensitivity: usually used when discussing Multilevel Security (MLS). A
       sensitivity level describes how important or secret the data should
       be. As the sensitivity level increases, so does the importance of the
       secrecy, or confidentiality, of the data.

16.3. Understanding MAC Labels

   A MAC label is a security attribute which may be applied to subjects and
   objects throughout the system. When setting a label, the administrator
   must understand its implications in order to prevent unexpected or
   undesired behavior of the system. The attributes available on an object
   depend on the loaded policy module, as policy modules interpret their
   attributes in different ways.

   The security label on an object is used as a part of a security access
   control decision by a policy. With some policies, the label contains all
   of the information necessary to make a decision. In other policies, the
   labels may be processed as part of a larger rule set.

   There are two types of label policies: single label and multi label. By
   default, the system will use single label. The administrator should be
   aware of the pros and cons of each in order to implement policies which
   meet the requirements of the system's security model.

   A single label security policy only permits one label to be used for every
   subject or object. Since a single label policy enforces one set of access
   permissions across the entire system, it provides lower administration
   overhead, but decreases the flexibility of policies which support
   labeling. However, in many environments, a single label policy may be all
   that is required.

   A single label policy is somewhat similar to DAC as root configures the
   policies so that users are placed in the appropriate categories and access
   levels. A notable difference is that many policy modules can also restrict
   root. Basic control over objects will then be released to the group, but
   root may revoke or modify the settings at any time.

   When appropriate, a multi label policy can be set on a UFS file system by
   passing multilabel to tunefs(8). A multi label policy permits each subject
   or object to have its own independent MAC label. The decision to use a
   multi label or single label policy is only required for policies which
   implement the labeling feature, such as biba, lomac, and mls. Some
   policies, such as seeotheruids, portacl and partition, do not use labels
   at all.

   Using a multi label policy on a partition and establishing a multi label
   security model can increase administrative overhead as everything in that
   file system has a label. This includes directories, files, and even device
   nodes.

   The following command will set multilabel on the specified UFS file
   system. This may only be done in single-user mode and is not a requirement
   for the swap file system:

 # tunefs -l enable /

  Note:

   Some users have experienced problems with setting the multilabel flag on
   the root partition. If this is the case, please review Section 16.8,
   "Troubleshooting the MAC Framework".

   Since the multi label policy is set on a per-file system basis, a multi
   label policy may not be needed if the file system layout is well designed.
   Consider an example security MAC model for a FreeBSD web server. This
   machine uses the single label, biba/high, for everything in the default
   file systems. If the web server needs to run at biba/low to prevent write
   up capabilities, it could be installed to a separate UFS /usr/local file
   system set at biba/low.

  16.3.1. Label Configuration

   Virtually all aspects of label policy module configuration will be
   performed using the base system utilities. These commands provide a simple
   interface for object or subject configuration or the manipulation and
   verification of the configuration.

   All configuration may be done using setfmac, which is used to set MAC
   labels on system objects, and setpmac, which is used to set the labels on
   system subjects. For example, to set the biba MAC label to high on test:

 # setfmac biba/high test

   If the configuration is successful, the prompt will be returned without
   error. A common error is Permission denied which usually occurs when the
   label is being set or modified on a restricted object. Other conditions
   may produce different failures. For instance, the file may not be owned by
   the user attempting to relabel the object, the object may not exist, or
   the object may be read-only. A mandatory policy will not allow the process
   to relabel the file, maybe because of a property of the file, a property
   of the process, or a property of the proposed new label value. For
   example, if a user running at low integrity tries to change the label of a
   high integrity file, or a user running at low integrity tries to change
   the label of a low integrity file to a high integrity label, these
   operations will fail.

   The system administrator may use setpmac to override the policy module's
   settings by assigning a different label to the invoked process:

 # setfmac biba/high test
 Permission denied
 # setpmac biba/low setfmac biba/high test
 # getfmac test
 test: biba/high

   For currently running processes, such as sendmail, getpmac is usually used
   instead. This command takes a process ID (PID) in place of a command name.
   If users attempt to manipulate a file not in their access, subject to the
   rules of the loaded policy modules, the Operation not permitted error will
   be displayed.

  16.3.2. Predefined Labels

   A few FreeBSD policy modules which support the labeling feature offer
   three predefined labels: low, equal, and high, where:

     * low is considered the lowest label setting an object or subject may
       have. Setting this on objects or subjects blocks their access to
       objects or subjects marked high.

     * equal sets the subject or object to be disabled or unaffected and
       should only be placed on objects considered to be exempt from the
       policy.

     * high grants an object or subject the highest setting available in the
       Biba and MLS policy modules.

   Such policy modules include mac_biba(4), mac_mls(4) and mac_lomac(4). Each
   of the predefined labels establishes a different information flow
   directive. Refer to the manual page of the module to determine the traits
   of the generic label configurations.

  16.3.3. Numeric Labels

   The Biba and MLS policy modules support a numeric label which may be set
   to indicate the precise level of hierarchical control. This numeric level
   is used to partition or sort information into different groups of
   classification, only permitting access to that group or a higher group
   level. For example:

 biba/10:2+3+6(5:2+3-20:2+3+4+5+6)

   may be interpreted as "Biba Policy Label/Grade 10:Compartments 2, 3 and 6:
   (grade 5 ...")

   In this example, the first grade would be considered the effective grade
   with effective compartments, the second grade is the low grade, and the
   last one is the high grade. In most configurations, such fine-grained
   settings are not needed as they are considered to be advanced
   configurations.

   System objects only have a current grade and compartment. System subjects
   reflect the range of available rights in the system, and network
   interfaces, where they are used for access control.

   The grade and compartments in a subject and object pair are used to
   construct a relationship known as dominance, in which a subject dominates
   an object, the object dominates the subject, neither dominates the other,
   or both dominate each other. The "both dominate" case occurs when the two
   labels are equal. Due to the information flow nature of Biba, a user has
   rights to a set of compartments that might correspond to projects, but
   objects also have a set of compartments. Users may have to subset their
   rights using su or setpmac in order to access objects in a compartment
   from which they are not restricted.

  16.3.4. User Labels

   Users are required to have labels so that their files and processes
   properly interact with the security policy defined on the system. This is
   configured in /etc/login.conf using login classes. Every policy module
   that uses labels will implement the user class setting.

   To set the user class default label which will be enforced by MAC, add a
   label entry. An example label entry containing every policy module is
   displayed below. Note that in a real configuration, the administrator
   would never enable every policy module. It is recommended that the rest of
   this chapter be reviewed before any configuration is implemented.

 default:\
         :copyright=/etc/COPYRIGHT:\
         :welcome=/etc/motd:\
         :setenv=MAIL=/var/mail/$,BLOCKSIZE=K:\
         :path=~/bin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin:\
         :manpath=/usr/share/man /usr/local/man:\
         :nologin=/usr/sbin/nologin:\
         :cputime=1h30m:\
         :datasize=8M:\
         :vmemoryuse=100M:\
         :stacksize=2M:\
         :memorylocked=4M:\
         :memoryuse=8M:\
         :filesize=8M:\
         :coredumpsize=8M:\
         :openfiles=24:\
         :maxproc=32:\
         :priority=0:\
         :requirehome:\
         :passwordtime=91d:\
         :umask=022:\
         :ignoretime@:\
         :label=partition/13,mls/5,biba/10(5-15),lomac/10[2]:

   While users can not modify the default value, they may change their label
   after they login, subject to the constraints of the policy. The example
   above tells the Biba policy that a process's minimum integrity is 5, its
   maximum is 15, and the default effective label is 10. The process will run
   at 10 until it chooses to change label, perhaps due to the user using
   setpmac, which will be constrained by Biba to the configured range.

   After any change to login.conf, the login class capability database must
   be rebuilt using cap_mkdb.

   Many sites have a large number of users requiring several different user
   classes. In depth planning is required as this can become difficult to
   manage.

  16.3.5. Network Interface Labels

   Labels may be set on network interfaces to help control the flow of data
   across the network. Policies using network interface labels function in
   the same way that policies function with respect to objects. Users at high
   settings in Biba, for example, will not be permitted to access network
   interfaces with a label of low.

   When setting the MAC label on network interfaces, maclabel may be passed
   to ifconfig:

 # ifconfig bge0 maclabel biba/equal

   This example will set the MAC label of biba/equal on the bge0 interface.
   When using a setting similar to biba/high(low-high), the entire label
   should be quoted to prevent an error from being returned.

   Each policy module which supports labeling has a tunable which may be used
   to disable the MAC label on network interfaces. Setting the label to equal
   will have a similar effect. Review the output of sysctl, the policy manual
   pages, and the information in the rest of this chapter for more
   information on those tunables.

16.4. Planning the Security Configuration

   Before implementing any MAC policies, a planning phase is recommended.
   During the planning stages, an administrator should consider the
   implementation requirements and goals, such as:

     * How to classify information and resources available on the target
       systems.

     * Which information or resources to restrict access to along with the
       type of restrictions that should be applied.

     * Which MAC modules will be required to achieve this goal.

   A trial run of the trusted system and its configuration should occur
   before a MAC implementation is used on production systems. Since different
   environments have different needs and requirements, establishing a
   complete security profile will decrease the need of changes once the
   system goes live.

   Consider how the MAC framework augments the security of the system as a
   whole. The various security policy modules provided by the MAC framework
   could be used to protect the network and file systems or to block users
   from accessing certain ports and sockets. Perhaps the best use of the
   policy modules is to load several security policy modules at a time in
   order to provide a MLS environment. This approach differs from a hardening
   policy, which typically hardens elements of a system which are used only
   for specific purposes. The downside to MLS is increased administrative
   overhead.

   The overhead is minimal when compared to the lasting effect of a framework
   which provides the ability to pick and choose which policies are required
   for a specific configuration and which keeps performance overhead down.
   The reduction of support for unneeded policies can increase the overall
   performance of the system as well as offer flexibility of choice. A good
   implementation would consider the overall security requirements and
   effectively implement the various security policy modules offered by the
   framework.

   A system utilizing MAC guarantees that a user will not be permitted to
   change security attributes at will. All user utilities, programs, and
   scripts must work within the constraints of the access rules provided by
   the selected security policy modules and control of the MAC access rules
   is in the hands of the system administrator.

   It is the duty of the system administrator to carefully select the correct
   security policy modules. For an environment that needs to limit access
   control over the network, the mac_portacl(4), mac_ifoff(4), and
   mac_biba(4) policy modules make good starting points. For an environment
   where strict confidentiality of file system objects is required, consider
   the mac_bsdextended(4) and mac_mls(4) policy modules.

   Policy decisions could be made based on network configuration. If only
   certain users should be permitted access to ssh(1), the mac_portacl(4)
   policy module is a good choice. In the case of file systems, access to
   objects might be considered confidential to some users, but not to others.
   As an example, a large development team might be broken off into smaller
   projects where developers in project A might not be permitted to access
   objects written by developers in project B. Yet both projects might need
   to access objects created by developers in project C. Using the different
   security policy modules provided by the MAC framework, users could be
   divided into these groups and then given access to the appropriate
   objects.

   Each security policy module has a unique way of dealing with the overall
   security of a system. Module selection should be based on a well thought
   out security policy which may require revision and reimplementation.
   Understanding the different security policy modules offered by the MAC
   framework will help administrators choose the best policies for their
   situations.

   The rest of this chapter covers the available modules, describes their use
   and configuration, and in some cases, provides insight on applicable
   situations.

  Caution:

   Implementing MAC is much like implementing a firewall since care must be
   taken to prevent being completely locked out of the system. The ability to
   revert back to a previous configuration should be considered and the
   implementation of MAC over a remote connection should be done with extreme
   caution.

16.5. Available MAC Policies

   The default FreeBSD kernel includes options MAC. This means that every
   module included with the MAC framework can be loaded with kldload as a
   run-time kernel module. After testing the module, add the module name to
   /boot/loader.conf so that it will load during boot. Each module also
   provides a kernel option for those administrators who choose to compile
   their own custom kernel.

   FreeBSD includes a group of policies that will cover most security
   requirements. Each policy is summarized below. The last three policies
   support integer settings in place of the three default labels.

  16.5.1. The MAC See Other UIDs Policy

   Module name: mac_seeotheruids.ko

   Kernel configuration line: options MAC_SEEOTHERUIDS

   Boot option: mac_seeotheruids_load="YES"

   The mac_seeotheruids(4) module extends the security.bsd.see_other_uids and
   security.bsd.see_other_gids sysctl tunables. This option does not require
   any labels to be set before configuration and can operate transparently
   with other modules.

   After loading the module, the following sysctl tunables may be used to
   control its features:

     * security.mac.seeotheruids.enabled enables the module and implements
       the default settings which deny users the ability to view processes
       and sockets owned by other users.

     * security.mac.seeotheruids.specificgid_enabled allows specified groups
       to be exempt from this policy. To exempt specific groups, use the
       security.mac.seeotheruids.specificgid=XXX sysctl tunable, replacing
       XXX with the numeric group ID to be exempted.

     * security.mac.seeotheruids.primarygroup_enabled is used to exempt
       specific primary groups from this policy. When using this tunable,
       security.mac.seeotheruids.specificgid_enabled may not be set.

  16.5.2. The MAC BSD Extended Policy

   Module name: mac_bsdextended.ko

   Kernel configuration line: options MAC_BSDEXTENDED

   Boot option: mac_bsdextended_load="YES"

   The mac_bsdextended(4) module enforces a file system firewall. It provides
   an extension to the standard file system permissions model, permitting an
   administrator to create a firewall-like ruleset to protect files,
   utilities, and directories in the file system hierarchy. When access to a
   file system object is attempted, the list of rules is iterated until
   either a matching rule is located or the end is reached. This behavior may
   be changed using security.mac.bsdextended.firstmatch_enabled. Similar to
   other firewall modules in FreeBSD, a file containing the access control
   rules can be created and read by the system at boot time using an
   rc.conf(5) variable.

   The rule list may be entered using ugidfw(8) which has a syntax similar to
   ipfw(8). More tools can be written by using the functions in the
   libugidfw(3) library.

   After the mac_bsdextended(4) module has been loaded, the following command
   may be used to list the current rule configuration:

 # ugidfw list
 0 slots, 0 rules

   By default, no rules are defined and everything is completely accessible.
   To create a rule which blocks all access by users but leaves root
   unaffected:

 # ugidfw add subject not uid root new object not uid root mode n

   While this rule is simple to implement, it is a very bad idea as it blocks
   all users from issuing any commands. A more realistic example blocks user1
   all access, including directory listings, to user2's home directory:

 # ugidfw set 2 subject uid user1 object uid user2 mode n
 # ugidfw set 3 subject uid user1 object gid user2 mode n

   Instead of user1, not uid user2 could be used in order to enforce the same
   access restrictions for all users. However, the root user is unaffected by
   these rules.

  Note:

   Extreme caution should be taken when working with this module as incorrect
   use could block access to certain parts of the file system.

  16.5.3. The MAC Interface Silencing Policy

   Module name: mac_ifoff.ko

   Kernel configuration line: options MAC_IFOFF

   Boot option: mac_ifoff_load="YES"

   The mac_ifoff(4) module is used to disable network interfaces on the fly
   and to keep network interfaces from being brought up during system boot.
   It does not use labels and does not depend on any other MAC modules.

   Most of this module's control is performed through these sysctl tunables:

     * security.mac.ifoff.lo_enabled enables or disables all traffic on the
       loopback, lo(4), interface.

     * security.mac.ifoff.bpfrecv_enabled enables or disables all traffic on
       the Berkeley Packet Filter interface, bpf(4).

     * security.mac.ifoff.other_enabled enables or disables traffic on all
       other interfaces.

   One of the most common uses of mac_ifoff(4) is network monitoring in an
   environment where network traffic should not be permitted during the boot
   sequence. Another use would be to write a script which uses an application
   such as security/aide to automatically block network traffic if it finds
   new or altered files in protected directories.

  16.5.4. The MAC Port Access Control List Policy

   Module name: mac_portacl.ko

   Kernel configuration line: MAC_PORTACL

   Boot option: mac_portacl_load="YES"

   The mac_portacl(4) module is used to limit binding to local TCP and UDP
   ports, making it possible to allow non-root users to bind to specified
   privileged ports below 1024.

   Once loaded, this module enables the MAC policy on all sockets. The
   following tunables are available:

     * security.mac.portacl.enabled enables or disables the policy
       completely.

     * security.mac.portacl.port_high sets the highest port number that
       mac_portacl(4) protects.

     * security.mac.portacl.suser_exempt, when set to a non-zero value,
       exempts the root user from this policy.

     * security.mac.portacl.rules specifies the policy as a text string of
       the form rule[,rule,...], with as many rules as needed, and where each
       rule is of the form idtype:id:protocol:port. The idtype is either uid
       or gid. The protocol parameter can be tcp or udp. The port parameter
       is the port number to allow the specified user or group to bind to.
       Only numeric values can be used for the user ID, group ID, and port
       parameters.

   By default, ports below 1024 can only be used by privileged processes
   which run as root. For mac_portacl(4) to allow non-privileged processes to
   bind to ports below 1024, set the following tunables as follows:

 # sysctl security.mac.portacl.port_high=1023
 # sysctl net.inet.ip.portrange.reservedlow=0
 # sysctl net.inet.ip.portrange.reservedhigh=0

   To prevent the root user from being affected by this policy, set
   security.mac.portacl.suser_exempt to a non-zero value.

 # sysctl security.mac.portacl.suser_exempt=1

   To allow the www user with UID 80 to bind to port 80 without ever needing
   root privilege:

 # sysctl security.mac.portacl.rules=uid:80:tcp:80

   This next example permits the user with the UID of 1001 to bind to TCP
   ports 110 (POP3) and 995 (POP3s):

 # sysctl security.mac.portacl.rules=uid:1001:tcp:110,uid:1001:tcp:995

  16.5.5. The MAC Partition Policy

   Module name: mac_partition.ko

   Kernel configuration line: options MAC_PARTITION

   Boot option: mac_partition_load="YES"

   The mac_partition(4) policy drops processes into specific "partitions"
   based on their MAC label. Most configuration for this policy is done using
   setpmac(8). One sysctl tunable is available for this policy:

     * security.mac.partition.enabled enables the enforcement of MAC process
       partitions.

   When this policy is enabled, users will only be permitted to see their
   processes, and any others within their partition, but will not be
   permitted to work with utilities outside the scope of this partition. For
   instance, a user in the insecure class will not be permitted to access top
   as well as many other commands that must spawn a process.

   This example adds top to the label set on users in the insecure class. All
   processes spawned by users in the insecure class will stay in the
   partition/13 label.

 # setpmac partition/13 top

   This command displays the partition label and the process list:

 # ps Zax

   This command displays another user's process partition label and that
   user's currently running processes:

 # ps -ZU trhodes

  Note:

   Users can see processes in root's label unless the mac_seeotheruids(4)
   policy is loaded.

  16.5.6. The MAC Multi-Level Security Module

   Module name: mac_mls.ko

   Kernel configuration line: options MAC_MLS

   Boot option: mac_mls_load="YES"

   The mac_mls(4) policy controls access between subjects and objects in the
   system by enforcing a strict information flow policy.

   In MLS environments, a "clearance" level is set in the label of each
   subject or object, along with compartments. Since these clearance levels
   can reach numbers greater than several thousand, it would be a daunting
   task to thoroughly configure every subject or object. To ease this
   administrative overhead, three labels are included in this policy:
   mls/low, mls/equal, and mls/high, where:

     * Anything labeled with mls/low will have a low clearance level and not
       be permitted to access information of a higher level. This label also
       prevents objects of a higher clearance level from writing or passing
       information to a lower level.

     * mls/equal should be placed on objects which should be exempt from the
       policy.

     * mls/high is the highest level of clearance possible. Objects assigned
       this label will hold dominance over all other objects in the system;
       however, they will not permit the leaking of information to objects of
       a lower class.

   MLS provides:

     * A hierarchical security level with a set of non-hierarchical
       categories.

     * Fixed rules of no read up, no write down. This means that a subject
       can have read access to objects on its own level or below, but not
       above. Similarly, a subject can have write access to objects on its
       own level or above, but not beneath.

     * Secrecy, or the prevention of inappropriate disclosure of data.

     * A basis for the design of systems that concurrently handle data at
       multiple sensitivity levels without leaking information between secret
       and confidential.

   The following sysctl tunables are available:

     * security.mac.mls.enabled is used to enable or disable the MLS policy.

     * security.mac.mls.ptys_equal labels all pty(4) devices as mls/equal
       during creation.

     * security.mac.mls.revocation_enabled revokes access to objects after
       their label changes to a label of a lower grade.

     * security.mac.mls.max_compartments sets the maximum number of
       compartment levels allowed on a system.

   To manipulate MLS labels, use setfmac(8). To assign a label to an object:

 # setfmac mls/5 test

   To get the MLS label for the file test:

 # getfmac test

   Another approach is to create a master policy file in /etc/ which
   specifies the MLS policy information and to feed that file to setfmac.

   When using the MLS policy module, an administrator plans to control the
   flow of sensitive information. The default block read up block write down
   sets everything to a low state. Everything is accessible and an
   administrator slowly augments the confidentiality of the information.

   Beyond the three basic label options, an administrator may group users and
   groups as required to block the information flow between them. It might be
   easier to look at the information in clearance levels using descriptive
   words, such as classifications of Confidential, Secret, and Top Secret.
   Some administrators instead create different groups based on project
   levels. Regardless of the classification method, a well thought out plan
   must exist before implementing a restrictive policy.

   Some example situations for the MLS policy module include an e-commerce
   web server, a file server holding critical company information, and
   financial institution environments.

  16.5.7. The MAC Biba Module

   Module name: mac_biba.ko

   Kernel configuration line: options MAC_BIBA

   Boot option: mac_biba_load="YES"

   The mac_biba(4) module loads the MAC Biba policy. This policy is similar
   to the MLS policy with the exception that the rules for information flow
   are slightly reversed. This is to prevent the downward flow of sensitive
   information whereas the MLS policy prevents the upward flow of sensitive
   information.

   In Biba environments, an "integrity" label is set on each subject or
   object. These labels are made up of hierarchical grades and
   non-hierarchical components. As a grade ascends, so does its integrity.

   Supported labels are biba/low, biba/equal, and biba/high, where:

     * biba/low is considered the lowest integrity an object or subject may
       have. Setting this on objects or subjects blocks their write access to
       objects or subjects marked as biba/high, but will not prevent read
       access.

     * biba/equal should only be placed on objects considered to be exempt
       from the policy.

     * biba/high permits writing to objects set at a lower label, but does
       not permit reading that object. It is recommended that this label be
       placed on objects that affect the integrity of the entire system.

   Biba provides:

     * Hierarchical integrity levels with a set of non-hierarchical integrity
       categories.

     * Fixed rules are no write up, no read down, the opposite of MLS. A
       subject can have write access to objects on its own level or below,
       but not above. Similarly, a subject can have read access to objects on
       its own level or above, but not below.

     * Integrity by preventing inappropriate modification of data.

     * Integrity levels instead of MLS sensitivity levels.

   The following tunables can be used to manipulate the Biba policy:

     * security.mac.biba.enabled is used to enable or disable enforcement of
       the Biba policy on the target machine.

     * security.mac.biba.ptys_equal is used to disable the Biba policy on
       pty(4) devices.

     * security.mac.biba.revocation_enabled forces the revocation of access
       to objects if the label is changed to dominate the subject.

   To access the Biba policy setting on system objects, use setfmac and
   getfmac:

 # setfmac biba/low test
 # getfmac test
 test: biba/low

   Integrity, which is different from sensitivity, is used to guarantee that
   information is not manipulated by untrusted parties. This includes
   information passed between subjects and objects. It ensures that users
   will only be able to modify or access information they have been given
   explicit access to. The mac_biba(4) security policy module permits an
   administrator to configure which files and programs a user may see and
   invoke while assuring that the programs and files are trusted by the
   system for that user.

   During the initial planning phase, an administrator must be prepared to
   partition users into grades, levels, and areas. The system will default to
   a high label once this policy module is enabled, and it is up to the
   administrator to configure the different grades and levels for users.
   Instead of using clearance levels, a good planning method could include
   topics. For instance, only allow developers modification access to the
   source code repository, source code compiler, and other development
   utilities. Other users would be grouped into other categories such as
   testers, designers, or end users and would only be permitted read access.

   A lower integrity subject is unable to write to a higher integrity subject
   and a higher integrity subject cannot list or read a lower integrity
   object. Setting a label at the lowest possible grade could make it
   inaccessible to subjects. Some prospective environments for this security
   policy module would include a constrained web server, a development and
   test machine, and a source code repository. A less useful implementation
   would be a personal workstation, a machine used as a router, or a network
   firewall.

  16.5.8. The MAC Low-watermark Module

   Module name: mac_lomac.ko

   Kernel configuration line: options MAC_LOMAC

   Boot option: mac_lomac_load="YES"

   Unlike the MAC Biba policy, the mac_lomac(4) policy permits access to
   lower integrity objects only after decreasing the integrity level to not
   disrupt any integrity rules.

   The Low-watermark integrity policy works almost identically to Biba, with
   the exception of using floating labels to support subject demotion via an
   auxiliary grade compartment. This secondary compartment takes the form
   [auxgrade]. When assigning a policy with an auxiliary grade, use the
   syntax lomac/10[2], where 2 is the auxiliary grade.

   This policy relies on the ubiquitous labeling of all system objects with
   integrity labels, permitting subjects to read from low integrity objects
   and then downgrading the label on the subject to prevent future writes to
   high integrity objects using [auxgrade]. The policy may provide greater
   compatibility and require less initial configuration than Biba.

   Like the Biba and MLS policies, setfmac and setpmac are used to place
   labels on system objects:

 # setfmac /usr/home/trhodes lomac/high[low]
 # getfmac /usr/home/trhodes lomac/high[low]

   The auxiliary grade low is a feature provided only by the MAC LOMAC
   policy.

16.6. User Lock Down

   This example considers a relatively small storage system with fewer than
   fifty users. Users will have login capabilities and are permitted to store
   data and access resources.

   For this scenario, the mac_bsdextended(4) and mac_seeotheruids(4) policy
   modules could co-exist and block access to system objects while hiding
   user processes.

   Begin by adding the following line to /boot/loader.conf:

 mac_seeotheruids_load="YES"

   The mac_bsdextended(4) security policy module may be activated by adding
   this line to /etc/rc.conf:

 ugidfw_enable="YES"

   Default rules stored in /etc/rc.bsdextended will be loaded at system
   initialization. However, the default entries may need modification. Since
   this machine is expected only to service users, everything may be left
   commented out except the last two lines in order to force the loading of
   user owned system objects by default.

   Add the required users to this machine and reboot. For testing purposes,
   try logging in as a different user across two consoles. Run ps aux to see
   if processes of other users are visible. Verify that running ls(1) on
   another user's home directory fails.

   Do not try to test with the root user unless the specific sysctls have
   been modified to block super user access.

  Note:

   When a new user is added, their mac_bsdextended(4) rule will not be in the
   ruleset list. To update the ruleset quickly, unload the security policy
   module and reload it again using kldunload(8) and kldload(8).

16.7. Nagios in a MAC Jail

   This section demonstrates the steps that are needed to implement the
   Nagios network monitoring system in a MAC environment. This is meant as an
   example which still requires the administrator to test that the
   implemented policy meets the security requirements of the network before
   using in a production environment.

   This example requires multilabel to be set on each file system. It also
   assumes that net-mgmt/nagios-plugins, net-mgmt/nagios, and www/apache22
   are all installed, configured, and working correctly before attempting the
   integration into the MAC framework.

  16.7.1. Create an Insecure User Class

   Begin the procedure by adding the following user class to /etc/login.conf:

 insecure:\
 :copyright=/etc/COPYRIGHT:\
 :welcome=/etc/motd:\
 :setenv=MAIL=/var/mail/$,BLOCKSIZE=K:\
 :path=~/bin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin
 :manpath=/usr/share/man /usr/local/man:\
 :nologin=/usr/sbin/nologin:\
 :cputime=1h30m:\
 :datasize=8M:\
 :vmemoryuse=100M:\
 :stacksize=2M:\
 :memorylocked=4M:\
 :memoryuse=8M:\
 :filesize=8M:\
 :coredumpsize=8M:\
 :openfiles=24:\
 :maxproc=32:\
 :priority=0:\
 :requirehome:\
 :passwordtime=91d:\
 :umask=022:\
 :ignoretime@:\
 :label=biba/10(10-10):

   Then, add the following line to the default user class section:

 :label=biba/high:

   Save the edits and issue the following command to rebuild the database:

 # cap_mkdb /etc/login.conf

  16.7.2. Configure Users

   Set the root user to the default class using:

 # pw usermod root -L default

   All user accounts that are not root will now require a login class. The
   login class is required, otherwise users will be refused access to common
   commands. The following sh script should do the trick:

 # for x in `awk -F: '($3 >= 1001) && ($3 != 65534) { print $1 }' \
         /etc/passwd`; do pw usermod $x -L default; done;

   Next, drop the nagios and www accounts into the insecure class:

 # pw usermod nagios -L insecure
 # pw usermod www -L insecure

  16.7.3. Create the Contexts File

   A contexts file should now be created as /etc/policy.contexts:

 # This is the default BIBA policy for this system.

 # System:
 /var/run(/.*)?                  biba/equal

 /dev/(/.*)?                     biba/equal

 /var                            biba/equal
 /var/spool(/.*)?                biba/equal

 /var/log(/.*)?                  biba/equal

 /tmp(/.*)?                      biba/equal
 /var/tmp(/.*)?                  biba/equal

 /var/spool/mqueue               biba/equal
 /var/spool/clientmqueue         biba/equal

 # For Nagios:
 /usr/local/etc/nagios(/.*)?     biba/10

 /var/spool/nagios(/.*)?         biba/10

 # For apache
 /usr/local/etc/apache(/.*)?     biba/10

   This policy enforces security by setting restrictions on the flow of
   information. In this specific configuration, users, including root, should
   never be allowed to access Nagios. Configuration files and processes that
   are a part of Nagios will be completely self contained or jailed.

   This file will be read after running setfsmac on every file system. This
   example sets the policy on the root file system:

 # setfsmac -ef /etc/policy.contexts /

   Next, add these edits to the main section of /etc/mac.conf:

 default_labels file ?biba
 default_labels ifnet ?biba
 default_labels process ?biba
 default_labels socket ?biba

  16.7.4. Loader Configuration

   To finish the configuration, add the following lines to /boot/loader.conf:

 mac_biba_load="YES"
 mac_seeotheruids_load="YES"
 security.mac.biba.trust_all_interfaces=1

   And the following line to the network card configuration stored in
   /etc/rc.conf. If the primary network configuration is done via DHCP, this
   may need to be configured manually after every system boot:

 maclabel biba/equal

  16.7.5. Testing the Configuration

   First, ensure that the web server and Nagios will not be started on system
   initialization and reboot. Ensure that root cannot access any of the files
   in the Nagios configuration directory. If root can list the contents of
   /var/spool/nagios, something is wrong. Instead, a "permission denied"
   error should be returned.

   If all seems well, Nagios, Apache, and Sendmail can now be started:

 # cd /etc/mail && make stop && \
 setpmac biba/equal make start && setpmac biba/10\(10-10\) apachectl start && \
 setpmac biba/10\(10-10\) /usr/local/etc/rc.d/nagios.sh forcestart

   Double check to ensure that everything is working properly. If not, check
   the log files for error messages. If needed, use sysctl(8) to disable the
   mac_biba(4) security policy module and try starting everything again as
   usual.

  Note:

   The root user can still change the security enforcement and edit its
   configuration files. The following command will permit the degradation of
   the security policy to a lower grade for a newly spawned shell:

 # setpmac biba/10 csh

   To block this from happening, force the user into a range using
   login.conf(5). If setpmac(8) attempts to run a command outside of the
   compartment's range, an error will be returned and the command will not be
   executed. In this case, set root to biba/high(high-high).

16.8. Troubleshooting the MAC Framework

   This section discusses common configuration errors and how to resolve
   them.

   The multilabel flag does not stay enabled on the root (/) partition:

           The following steps may resolve this transient error:

             1. Edit /etc/fstab and set the root partition to ro for
                read-only.

             2. Reboot into single user mode.

             3. Run tunefs -l enable on /.

             4. Reboot the system.

             5. Run mount -urw / and change the ro back to rw in /etc/fstab
                and reboot the system again.

             6. Double-check the output from mount to ensure that multilabel
                has been properly set on the root file system.

   After establishing a secure environment with MAC, Xorg no longer starts:

           This could be caused by the MAC partition policy or by a
           mislabeling in one of the MAC labeling policies. To debug, try the
           following:

             1. Check the error message. If the user is in the insecure
                class, the partition policy may be the culprit. Try setting
                the user's class back to the default class and rebuild the
                database with cap_mkdb. If this does not alleviate the
                problem, go to step two.

             2. Double-check that the label policies are set correctly for
                the user, Xorg, and the /dev entries.

             3. If neither of these resolve the problem, send the error
                message and a description of the environment to the FreeBSD
                general questions mailing list.

   The _secure_path: unable to stat .login_conf error appears:

           This error can appear when a user attempts to switch from the root
           user to another user in the system. This message usually occurs
           when the user has a higher label setting than that of the user
           they are attempting to become. For instance, if joe has a default
           label of biba/low and root has a label of biba/high, root cannot
           view joe's home directory. This will happen whether or not root
           has used su to become joe as the Biba integrity model will not
           permit root to view objects set at a lower integrity level.

   The system no longer recognizes root:

           When this occurs, whoami returns 0 and su returns who are you?.

           This can happen if a labeling policy has been disabled by
           sysctl(8) or the policy module was unloaded. If the policy is
           disabled, the login capabilities database needs to be
           reconfigured. Double check /etc/login.conf to ensure that all
           label options have been removed and rebuild the database with
           cap_mkdb.

           This may also happen if a policy restricts access to
           master.passwd. This is usually caused by an administrator altering
           the file under a label which conflicts with the general policy
           being used by the system. In these cases, the user information
           would be read by the system and access would be blocked as the
           file has inherited the new label. Disable the policy using
           sysctl(8) and everything should return to normal.

Chapter 17. Security Event Auditing

   Written by Tom Rhodes and Robert Watson.
   Table of Contents

   17.1. Synopsis

   17.2. Key Terms

   17.3. Audit Configuration

   17.4. Working with Audit Trails

17.1. Synopsis

   The FreeBSD operating system includes support for security event auditing.
   Event auditing supports reliable, fine-grained, and configurable logging
   of a variety of security-relevant system events, including logins,
   configuration changes, and file and network access. These log records can
   be invaluable for live system monitoring, intrusion detection, and
   postmortem analysis. FreeBSD implements Sun(TM)'s published Basic Security
   Module (BSM) Application Programming Interface (API) and file format, and
   is interoperable with the Solaris(TM) and Mac OS(R) X audit
   implementations.

   This chapter focuses on the installation and configuration of event
   auditing. It explains audit policies and provides an example audit
   configuration.

   After reading this chapter, you will know:

     * What event auditing is and how it works.

     * How to configure event auditing on FreeBSD for users and processes.

     * How to review the audit trail using the audit reduction and review
       tools.

   Before reading this chapter, you should:

     * Understand UNIX(R) and FreeBSD basics (Chapter 3, FreeBSD Basics).

     * Be familiar with the basics of kernel configuration/compilation
       (Chapter 8, Configuring the FreeBSD Kernel).

     * Have some familiarity with security and how it pertains to FreeBSD
       (Chapter 14, Security).

  Warning:

   The audit facility has some known limitations. Not all security-relevant
   system events are auditable and some login mechanisms, such as Xorg-based
   display managers and third-party daemons, do not properly configure
   auditing for user login sessions.

   The security event auditing facility is able to generate very detailed
   logs of system activity. On a busy system, trail file data can be very
   large when configured for high detail, exceeding gigabytes a week in some
   configurations. Administrators should take into account the disk space
   requirements associated with high volume audit configurations. For
   example, it may be desirable to dedicate a file system to /var/audit so
   that other file systems are not affected if the audit file system becomes
   full.

17.2. Key Terms

   The following terms are related to security event auditing:

     * event: an auditable event is any event that can be logged using the
       audit subsystem. Examples of security-relevant events include the
       creation of a file, the building of a network connection, or a user
       logging in. Events are either "attributable", meaning that they can be
       traced to an authenticated user, or "non-attributable". Examples of
       non-attributable events are any events that occur before
       authentication in the login process, such as bad password attempts.

     * class: a named set of related events which are used in selection
       expressions. Commonly used classes of events include "file creation"
       (fc), "exec" (ex), and "login_logout" (lo).

     * record: an audit log entry describing a security event. Records
       contain a record event type, information on the subject (user)
       performing the action, date and time information, information on any
       objects or arguments, and a success or failure condition.

     * trail: a log file consisting of a series of audit records describing
       security events. Trails are in roughly chronological order with
       respect to the time events completed. Only authorized processes are
       allowed to commit records to the audit trail.

     * selection expression: a string containing a list of prefixes and audit
       event class names used to match events.

     * preselection: the process by which the system identifies which events
       are of interest to the administrator. The preselection configuration
       uses a series of selection expressions to identify which classes of
       events to audit for which users, as well as global settings that apply
       to both authenticated and unauthenticated processes.

     * reduction: the process by which records from existing audit trails are
       selected for preservation, printing, or analysis. Likewise, the
       process by which undesired audit records are removed from the audit
       trail. Using reduction, administrators can implement policies for the
       preservation of audit data. For example, detailed audit trails might
       be kept for one month, but after that, trails might be reduced in
       order to preserve only login information for archival purposes.

17.3. Audit Configuration

   User space support for event auditing is installed as part of the base
   FreeBSD operating system. Kernel support is available in the GENERIC
   kernel by default, and auditd(8) can be enabled by adding the following
   line to /etc/rc.conf:

 auditd_enable="YES"

   Then, start the audit daemon:

 # service auditd start

   Users who prefer to compile a custom kernel must include the following
   line in their custom kernel configuration file:

 options AUDIT

  17.3.1. Event Selection Expressions

   Selection expressions are used in a number of places in the audit
   configuration to determine which events should be audited. Expressions
   contain a list of event classes to match. Selection expressions are
   evaluated from left to right, and two expressions are combined by
   appending one onto the other.

   Table 17.1, "Default Audit Event Classes" summarizes the default audit
   event classes:

   Table 17.1. Default Audit Event Classes

   Class Name      Description                       Action                   
   all        all                   Match all event classes.                  
   aa         authentication and                                              
              authorization         
   ad         administrative        Administrative actions performed on the   
                                    system as a whole.                        
   ap         application           Application defined action.               
   cl         file close            Audit calls to the close system call.     
                                    Audit program execution. Auditing of      
                                    command line arguments and environmental  
   ex         exec                  variables is controlled via               
                                    audit_control(5) using the argv and envv  
                                    parameters to the policy setting.         
   fa         file attribute access Audit the access of object attributes     
                                    such as stat(1) and pathconf(2).          
   fc         file create           Audit events where a file is created as a 
                                    result.                                   
   fd         file delete           Audit events where file deletion occurs.  
                                    Audit events where file attribute         
   fm         file attribute modify modification occurs, such as by chown(8), 
                                    chflags(1), and flock(2).                 
   fr         file read             Audit events in which data is read or     
                                    files are opened for reading.             
   fw         file write            Audit events in which data is written or  
                                    files are written or modified.            
   io         ioctl                 Audit use of the ioctl system call.       
                                    Audit various forms of Inter-Process      
   ip         ipc                   Communication, including POSIX pipes and  
                                    System V IPC operations.                  
   lo         login_logout          Audit login(1) and logout(1) events.      
   na         non attributable      Audit non-attributable events.            
   no         invalid class         Match no audit events.                    
   nt         network               Audit events related to network actions   
                                    such as connect(2) and accept(2).         
   ot         other                 Audit miscellaneous events.               
   pc         process               Audit process operations such as exec(3)  
                                    and exit(3).                              

   These audit event classes may be customized by modifying the audit_class
   and audit_event configuration files.

   Each audit event class may be combined with a prefix indicating whether
   successful/failed operations are matched, and whether the entry is adding
   or removing matching for the class and type. Table 17.2, "Prefixes for
   Audit Event Classes" summarizes the available prefixes:

   Table 17.2. Prefixes for Audit Event Classes

     Prefix                                Action                             
   +           Audit successful events in this class.                         
   -           Audit failed events in this class.                             
   ^           Audit neither successful nor failed events in this class.      
   ^+          Do not audit successful events in this class.                  
   ^-          Do not audit failed events in this class.                      

   If no prefix is present, both successful and failed instances of the event
   will be audited.

   The following example selection string selects both successful and failed
   login/logout events, but only successful execution events:

 lo,+ex

  17.3.2. Configuration Files

   The following configuration files for security event auditing are found in
   /etc/security:

     * audit_class: contains the definitions of the audit classes.

     * audit_control: controls aspects of the audit subsystem, such as
       default audit classes, minimum disk space to leave on the audit log
       volume, and maximum audit trail size.

     * audit_event: textual names and descriptions of system audit events and
       a list of which classes each event is in.

     * audit_user: user-specific audit requirements to be combined with the
       global defaults at login.

     * audit_warn: a customizable shell script used by auditd(8) to generate
       warning messages in exceptional situations, such as when space for
       audit records is running low or when the audit trail file has been
       rotated.

  Warning:

   Audit configuration files should be edited and maintained carefully, as
   errors in configuration may result in improper logging of events.

   In most cases, administrators will only need to modify audit_control and
   audit_user. The first file controls system-wide audit properties and
   policies and the second file may be used to fine-tune auditing by user.

    17.3.2.1. The audit_control File

   A number of defaults for the audit subsystem are specified in
   audit_control:

 dir:/var/audit
 dist:off
 flags:lo,aa
 minfree:5
 naflags:lo,aa
 policy:cnt,argv
 filesz:2M
 expire-after:10M

   The dir entry is used to set one or more directories where audit logs will
   be stored. If more than one directory entry appears, they will be used in
   order as they fill. It is common to configure audit so that audit logs are
   stored on a dedicated file system, in order to prevent interference
   between the audit subsystem and other subsystems if the file system fills.

   If the dist field is set to on or yes, hard links will be created to all
   trail files in /var/audit/dist.

   The flags field sets the system-wide default preselection mask for
   attributable events. In the example above, successful and failed
   login/logout events as well as authentication and authorization are
   audited for all users.

   The minfree entry defines the minimum percentage of free space for the
   file system where the audit trail is stored.

   The naflags entry specifies audit classes to be audited for non-attributed
   events, such as the login/logout process and authentication and
   authorization.

   The policy entry specifies a comma-separated list of policy flags
   controlling various aspects of audit behavior. The cnt indicates that the
   system should continue running despite an auditing failure (this flag is
   highly recommended). The other flag, argv, causes command line arguments
   to the execve(2) system call to be audited as part of command execution.

   The filesz entry specifies the maximum size for an audit trail before
   automatically terminating and rotating the trail file. A value of 0
   disables automatic log rotation. If the requested file size is below the
   minimum of 512k, it will be ignored and a log message will be generated.

   The expire-after field specifies when audit log files will expire and be
   removed.

    17.3.2.2. The audit_user File

   The administrator can specify further audit requirements for specific
   users in audit_user. Each line configures auditing for a user via two
   fields: the alwaysaudit field specifies a set of events that should always
   be audited for the user, and the neveraudit field specifies a set of
   events that should never be audited for the user.

   The following example entries audit login/logout events and successful
   command execution for root and file creation and successful command
   execution for www. If used with the default audit_control, the lo entry
   for root is redundant, and login/logout events will also be audited for
   www.

 root:lo,+ex:no
 www:fc,+ex:no

17.4. Working with Audit Trails

   Since audit trails are stored in the BSM binary format, several built-in
   tools are available to modify or convert these trails to text. To convert
   trail files to a simple text format, use praudit. To reduce the audit
   trail file for analysis, archiving, or printing purposes, use auditreduce.
   This utility supports a variety of selection parameters, including event
   type, event class, user, date or time of the event, and the file path or
   object acted on.

   For example, to dump the entire contents of a specified audit log in plain
   text:

 # praudit /var/audit/AUDITFILE

   Where AUDITFILE is the audit log to dump.

   Audit trails consist of a series of audit records made up of tokens, which
   praudit prints sequentially, one per line. Each token is of a specific
   type, such as header (an audit record header) or path (a file path from a
   name lookup). The following is an example of an execve event:

 header,133,10,execve(2),0,Mon Sep 25 15:58:03 2006, + 384 msec
 exec arg,finger,doug
 path,/usr/bin/finger
 attribute,555,root,wheel,90,24918,104944
 subject,robert,root,wheel,root,wheel,38439,38032,42086,128.232.9.100
 return,success,0
 trailer,133

   This audit represents a successful execve call, in which the command
   finger doug has been run. The exec arg token contains the processed
   command line presented by the shell to the kernel. The path token holds
   the path to the executable as looked up by the kernel. The attribute token
   describes the binary and includes the file mode. The subject token stores
   the audit user ID, effective user ID and group ID, real user ID and group
   ID, process ID, session ID, port ID, and login address. Notice that the
   audit user ID and real user ID differ as the user robert switched to the
   root account before running this command, but it is audited using the
   original authenticated user. The return token indicates the successful
   execution and the trailer concludes the record.

   XML output format is also supported and can be selected by including -x.

   Since audit logs may be very large, a subset of records can be selected
   using auditreduce. This example selects all audit records produced for the
   user trhodes stored in AUDITFILE:

 # auditreduce -u trhodes /var/audit/AUDITFILE | praudit

   Members of the audit group have permission to read audit trails in
   /var/audit. By default, this group is empty, so only the root user can
   read audit trails. Users may be added to the audit group in order to
   delegate audit review rights. As the ability to track audit log contents
   provides significant insight into the behavior of users and processes, it
   is recommended that the delegation of audit review rights be performed
   with caution.

  17.4.1. Live Monitoring Using Audit Pipes

   Audit pipes are cloning pseudo-devices which allow applications to tap the
   live audit record stream. This is primarily of interest to authors of
   intrusion detection and system monitoring applications. However, the audit
   pipe device is a convenient way for the administrator to allow live
   monitoring without running into problems with audit trail file ownership
   or log rotation interrupting the event stream. To track the live audit
   event stream:

 # praudit /dev/auditpipe

   By default, audit pipe device nodes are accessible only to the root user.
   To make them accessible to the members of the audit group, add a devfs
   rule to /etc/devfs.rules:

 add path 'auditpipe*' mode 0440 group audit

   See devfs.rules(5) for more information on configuring the devfs file
   system.

  Warning:

   It is easy to produce audit event feedback cycles, in which the viewing of
   each audit event results in the generation of more audit events. For
   example, if all network I/O is audited, and praudit is run from an SSH
   session, a continuous stream of audit events will be generated at a high
   rate, as each event being printed will generate another event. For this
   reason, it is advisable to run praudit on an audit pipe device from
   sessions without fine-grained I/O auditing.

  17.4.2. Rotating and Compressing Audit Trail Files

   Audit trails are written to by the kernel and managed by the audit daemon,
   auditd(8). Administrators should not attempt to use newsyslog.conf(5) or
   other tools to directly rotate audit logs. Instead, audit should be used
   to shut down auditing, reconfigure the audit system, and perform log
   rotation. The following command causes the audit daemon to create a new
   audit log and signal the kernel to switch to using the new log. The old
   log will be terminated and renamed, at which point it may then be
   manipulated by the administrator:

 # audit -n

   If auditd(8) is not currently running, this command will fail and an error
   message will be produced.

   Adding the following line to /etc/crontab will schedule this rotation
   every twelve hours:

 0     */12       *       *       *       root    /usr/sbin/audit -n

   The change will take effect once /etc/crontab is saved.

   Automatic rotation of the audit trail file based on file size is possible
   using filesz in audit_control as described in Section 17.3.2.1, "The
   audit_control File".

   As audit trail files can become very large, it is often desirable to
   compress or otherwise archive trails once they have been closed by the
   audit daemon. The audit_warn script can be used to perform customized
   operations for a variety of audit-related events, including the clean
   termination of audit trails when they are rotated. For example, the
   following may be added to /etc/security/audit_warn to compress audit
   trails on close:

 #
 # Compress audit trail files on close.
 #
 if [ "$1" = closefile ]; then
         gzip -9 $2
 fi

   Other archiving activities might include copying trail files to a
   centralized server, deleting old trail files, or reducing the audit trail
   to remove unneeded records. This script will be run only when audit trail
   files are cleanly terminated. It will not be run on trails left
   unterminated following an improper shutdown.

Chapter 18. Storage

   Table of Contents

   18.1. Synopsis

   18.2. Adding Disks

   18.3. Resizing and Growing Disks

   18.4. USB Storage Devices

   18.5. Creating and Using CD Media

   18.6. Creating and Using DVD Media

   18.7. Creating and Using Floppy Disks

   18.8. Backup Basics

   18.9. Memory Disks

   18.10. File System Snapshots

   18.11. Disk Quotas

   18.12. Encrypting Disk Partitions

   18.13. Encrypting Swap

   18.14. Highly Available Storage (HAST)

18.1. Synopsis

   This chapter covers the use of disks and storage media in FreeBSD. This
   includes SCSI and IDE disks, CD and DVD media, memory-backed disks, and
   USB storage devices.

   After reading this chapter, you will know:

     * How to add additional hard disks to a FreeBSD system.

     * How to grow the size of a disk's partition on FreeBSD.

     * How to configure FreeBSD to use USB storage devices.

     * How to use CD and DVD media on a FreeBSD system.

     * How to use the backup programs available under FreeBSD.

     * How to set up memory disks.

     * What file system snapshots are and how to use them efficiently.

     * How to use quotas to limit disk space usage.

     * How to encrypt disks and swap to secure them against attackers.

     * How to configure a highly available storage network.

   Before reading this chapter, you should:

     * Know how to configure and install a new FreeBSD kernel.

18.2. Adding Disks

   Originally contributed by David O'Brien.

   This section describes how to add a new SATA disk to a machine that
   currently only has a single drive. First, turn off the computer and
   install the drive in the computer following the instructions of the
   computer, controller, and drive manufacturers. Reboot the system and
   become root.

   Inspect /var/run/dmesg.boot to ensure the new disk was found. In this
   example, the newly added SATA drive will appear as ada1.

   For this example, a single large partition will be created on the new
   disk. The GPT partitioning scheme will be used in preference to the older
   and less versatile MBR scheme.

  Note:

   If the disk to be added is not blank, old partition information can be
   removed with gpart delete. See gpart(8) for details.

   The partition scheme is created, and then a single partition is added. To
   improve performance on newer disks with larger hardware block sizes, the
   partition is aligned to one megabyte boundaries:

 # gpart create -s GPT ada1
 # gpart add -t freebsd-ufs -a 1M ada1

   Depending on use, several smaller partitions may be desired. See gpart(8)
   for options to create partitions smaller than a whole disk.

   The disk partition information can be viewed with gpart show:

 % gpart show ada1
 =>        34  1465146988  ada1  GPT  (699G)
           34        2014        - free -  (1.0M)
         2048  1465143296     1  freebsd-ufs  (699G)
   1465145344        1678        - free -  (839K)

   A file system is created in the new partition on the new disk:

 # newfs -U /dev/ada1p1

   An empty directory is created as a mountpoint, a location for mounting the
   new disk in the original disk's file system:

 # mkdir /newdisk

   Finally, an entry is added to /etc/fstab so the new disk will be mounted
   automatically at startup:

 /dev/ada1p1     /newdisk        ufs     rw      2       2

   The new disk can be mounted manually, without restarting the system:

 # mount /newdisk

18.3. Resizing and Growing Disks

   Originally contributed by Allan Jude.

   A disk's capacity can increase without any changes to the data already
   present. This happens commonly with virtual machines, when the virtual
   disk turns out to be too small and is enlarged. Sometimes a disk image is
   written to a USB memory stick, but does not use the full capacity. Here we
   describe how to resize or grow disk contents to take advantage of
   increased capacity.

   Determine the device name of the disk to be resized by inspecting
   /var/run/dmesg.boot. In this example, there is only one SATA disk in the
   system, so the drive will appear as ada0.

   List the partitions on the disk to see the current configuration:

 # gpart show ada0
 =>      34  83886013  ada0  GPT  (48G) [CORRUPT]
         34       128     1  freebsd-boot  (64k)
        162  79691648     2  freebsd-ufs  (38G)
   79691810   4194236     3  freebsd-swap  (2G)
   83886046         1        - free -  (512B)

  Note:

   If the disk was formatted with the GPT partitioning scheme, it may show as
   "corrupted" because the GPT backup partition table is no longer at the end
   of the drive. Fix the backup partition table with gpart:

 # gpart recover ada0
 ada0 recovered

   Now the additional space on the disk is available for use by a new
   partition, or an existing partition can be expanded:

 # gpart show ada0
 =>       34  102399933  ada0  GPT  (48G)
          34        128     1  freebsd-boot  (64k)
         162   79691648     2  freebsd-ufs  (38G)
    79691810    4194236     3  freebsd-swap  (2G)
    83886046   18513921        - free -  (8.8G)

   Partitions can only be resized into contiguous free space. Here, the last
   partition on the disk is the swap partition, but the second partition is
   the one that needs to be resized. Swap partitions only contain temporary
   data, so it can safely be unmounted, deleted, and then recreate the third
   partition after resizing the second partition.

   Disable the swap partition:

 # swapoff /dev/ada0p3

   Delete the third partition, specified by the -i flag, from the disk ada0.

 # gpart delete -i 3 ada0
 ada0p3 deleted
 # gpart show ada0
 =>       34  102399933  ada0  GPT  (48G)
          34        128     1  freebsd-boot  (64k)
         162   79691648     2  freebsd-ufs  (38G)
    79691810   22708157        - free -  (10G)

  Warning:

   There is risk of data loss when modifying the partition table of a mounted
   file system. It is best to perform the following steps on an unmounted
   file system while running from a live CD-ROM or USB device. However, if
   absolutely necessary, a mounted file system can be resized after disabling
   GEOM safety features:

 # sysctl kern.geom.debugflags=16

   Resize the partition, leaving room to recreate a swap partition of the
   desired size. The partition to resize is specified with -i, and the new
   desired size with -s. Optionally, alignment of the partition is controlled
   with -a. This only modifies the size of the partition. The file system in
   the partition will be expanded in a separate step.

 # gpart resize -i 2 -s 47G -a 4k ada0
 ada0p2 resized
 # gpart show ada0
 =>       34  102399933  ada0  GPT  (48G)
          34        128     1  freebsd-boot  (64k)
         162   98566144     2  freebsd-ufs  (47G)
    98566306    3833661        - free -  (1.8G)

   Recreate the swap partition and activate it. If no size is specified with
   -s, all remaining space is used:

 # gpart add -t freebsd-swap -a 4k ada0
 ada0p3 added
 # gpart show ada0
 =>       34  102399933  ada0  GPT  (48G)
          34        128     1  freebsd-boot  (64k)
         162   98566144     2  freebsd-ufs  (47G)
    98566306    3833661     3  freebsd-swap  (1.8G)
 # swapon /dev/ada0p3

   Grow the UFS file system to use the new capacity of the resized partition:

 # growfs /dev/ada0p2
 Device is mounted read-write; resizing will result in temporary write suspension for /.
 It's strongly recommended to make a backup before growing the file system.
 OK to grow file system on /dev/ada0p2, mounted on /, from 38GB to 47GB? [Yes/No] Yes
 super-block backups (for fsck -b #) at:
  80781312, 82063552, 83345792, 84628032, 85910272, 87192512, 88474752,
  89756992, 91039232, 92321472, 93603712, 94885952, 96168192, 97450432

   If the file system is ZFS, the resize is triggered by running the online
   subcommand with -e:

 # zpool online -e zroot /dev/ada0p2

   Both the partition and the file system on it have now been resized to use
   the newly-available disk space.

18.4. USB Storage Devices

   Contributed by Marc Fonvieille.

   Many external storage solutions, such as hard drives, USB thumbdrives, and
   CD and DVD burners, use the Universal Serial Bus (USB). FreeBSD provides
   support for USB 1.x, 2.0, and 3.0 devices.

  Note:

   USB 3.0 support is not compatible with some hardware, including Haswell
   (Lynx point) chipsets. If FreeBSD boots with a failed with error 19
   message, disable xHCI/USB3 in the system BIOS.

   Support for USB storage devices is built into the GENERIC kernel. For a
   custom kernel, be sure that the following lines are present in the kernel
   configuration file:

 device scbus    # SCSI bus (required for ATA/SCSI)
 device da       # Direct Access (disks)
 device pass     # Passthrough device (direct ATA/SCSI access)
 device uhci     # provides USB 1.x support
 device ohci     # provides USB 1.x support
 device ehci     # provides USB 2.0 support
 device xhci     # provides USB 3.0 support
 device usb      # USB Bus (required)
 device umass    # Disks/Mass storage - Requires scbus and da
 device cd       # needed for CD and DVD burners

   FreeBSD uses the umass(4) driver which uses the SCSI subsystem to access
   USB storage devices. Since any USB device will be seen as a SCSI device by
   the system, if the USB device is a CD or DVD burner, do not include device
   atapicam in a custom kernel configuration file.

   The rest of this section demonstrates how to verify that a USB storage
   device is recognized by FreeBSD and how to configure the device so that it
   can be used.

  18.4.1. Device Configuration

   To test the USB configuration, plug in the USB device. Use dmesg to
   confirm that the drive appears in the system message buffer. It should
   look something like this:

 umass0: <STECH Simple Drive, class 0/0, rev 2.00/1.04, addr 3> on usbus0
 umass0:  SCSI over Bulk-Only; quirks = 0x0100
 umass0:4:0:-1: Attached to scbus4
 da0 at umass-sim0 bus 0 scbus4 target 0 lun 0
 da0: <STECH Simple Drive 1.04> Fixed Direct Access SCSI-4 device
 da0: Serial Number WD-WXE508CAN263
 da0: 40.000MB/s transfers
 da0: 152627MB (312581808 512 byte sectors: 255H 63S/T 19457C)
 da0: quirks=0x2<NO_6_BYTE>

   The brand, device node (da0), speed, and size will differ according to the
   device.

   Since the USB device is seen as a SCSI one, camcontrol can be used to list
   the USB storage devices attached to the system:

 # camcontrol devlist
 <STECH Simple Drive 1.04>          at scbus4 target 0 lun 0 (pass3,da0)

   Alternately, usbconfig can be used to list the device. Refer to
   usbconfig(8) for more information about this command.

 # usbconfig
 ugen0.3: <Simple Drive STECH> at usbus0, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=ON (2mA)

   If the device has not been formatted, refer to Section 18.2, "Adding
   Disks" for instructions on how to format and create partitions on the USB
   drive. If the drive comes with a file system, it can be mounted by root
   using the instructions in Section 3.7, "Mounting and Unmounting File
   Systems".

  Warning:

   Allowing untrusted users to mount arbitrary media, by enabling
   vfs.usermount as described below, should not be considered safe from a
   security point of view. Most file systems were not built to safeguard
   against malicious devices.

   To make the device mountable as a normal user, one solution is to make all
   users of the device a member of the operator group using pw(8). Next,
   ensure that operator is able to read and write the device by adding these
   lines to /etc/devfs.rules:

 [localrules=5]
 add path 'da*' mode 0660 group operator

  Note:

   If internal SCSI disks are also installed in the system, change the second
   line as follows:

 add path 'da[3-9]*' mode 0660 group operator

   This will exclude the first three SCSI disks (da0 to da2)from belonging to
   the operator group. Replace 3 with the number of internal SCSI disks.
   Refer to devfs.rules(5) for more information about this file.

   Next, enable the ruleset in /etc/rc.conf:

 devfs_system_ruleset="localrules"

   Then, instruct the system to allow regular users to mount file systems by
   adding the following line to /etc/sysctl.conf:

 vfs.usermount=1

   Since this only takes effect after the next reboot, use sysctl to set this
   variable now:

 # sysctl vfs.usermount=1
 vfs.usermount: 0 -> 1

   The final step is to create a directory where the file system is to be
   mounted. This directory needs to be owned by the user that is to mount the
   file system. One way to do that is for root to create a subdirectory owned
   by that user as /mnt/username. In the following example, replace username
   with the login name of the user and usergroup with the user's primary
   group:

 # mkdir /mnt/username
 # chown username:usergroup /mnt/username

   Suppose a USB thumbdrive is plugged in, and a device /dev/da0s1 appears.
   If the device is formatted with a FAT file system, the user can mount it
   using:

 % mount -t msdosfs -o -m=644,-M=755 /dev/da0s1 /mnt/username

   Before the device can be unplugged, it must be unmounted first:

 % umount /mnt/username

   After device removal, the system message buffer will show messages similar
   to the following:

 umass0: at uhub3, port 2, addr 3 (disconnected)
 da0 at umass-sim0 bus 0 scbus4 target 0 lun 0
 da0: <STECH Simple Drive 1.04> s/n WD-WXE508CAN263          detached
 (da0:umass-sim0:0:0:0): Periph destroyed

  18.4.2. Automounting Removable Media

   USB devices can be automatically mounted by uncommenting this line in
   /etc/auto_master:

 /media          -media          -nosuid

   Then add these lines to /etc/devd.conf:

 notify 100 {
         match "system" "GEOM";
         match "subsystem" "DEV";
         action "/usr/sbin/automount -c";
 };

   Reload the configuration if autofs(5) and devd(8) are already running:

 # service automount restart
 # service devd restart

   autofs(5) can be set to start at boot by adding this line to /etc/rc.conf:

 autofs_enable="YES"

   autofs(5) requires devd(8) to be enabled, as it is by default.

   Start the services immediately with:

 # service automount start
 # service automountd start
 # service autounmountd start
 # service devd start

   Each file system that can be automatically mounted appears as a directory
   in /media/. The directory is named after the file system label. If the
   label is missing, the directory is named after the device node.

   The file system is transparently mounted on the first access, and
   unmounted after a period of inactivity. Automounted drives can also be
   unmounted manually:

 # automount -fu

   This mechanism is typically used for memory cards and USB memory sticks.
   It can be used with any block device, including optical drives or iSCSI
   LUNs.

18.5. Creating and Using CD Media

   Contributed by Mike Meyer.

   Compact Disc (CD) media provide a number of features that differentiate
   them from conventional disks. They are designed so that they can be read
   continuously without delays to move the head between tracks. While CD
   media do have tracks, these refer to a section of data to be read
   continuously, and not a physical property of the disk. The ISO 9660 file
   system was designed to deal with these differences.

   The FreeBSD Ports Collection provides several utilities for burning and
   duplicating audio and data CDs. This chapter demonstrates the use of
   several command line utilities. For CD burning software with a graphical
   utility, consider installing the sysutils/xcdroast or sysutils/k3b
   packages or ports.

  18.5.1. Supported Devices

   Contributed by Marc Fonvieille.

   The GENERIC kernel provides support for SCSI, USB, and ATAPI CD readers
   and burners. If a custom kernel is used, the options that need to be
   present in the kernel configuration file vary by the type of device.

   For a SCSI burner, make sure these options are present:

 device scbus    # SCSI bus (required for ATA/SCSI)
 device da       # Direct Access (disks)
 device pass     # Passthrough device (direct ATA/SCSI access)
 device cd       # needed for CD and DVD burners

   For a USB burner, make sure these options are present:

 device scbus    # SCSI bus (required for ATA/SCSI)
 device da       # Direct Access (disks)
 device pass     # Passthrough device (direct ATA/SCSI access)
 device cd       # needed for CD and DVD burners
 device uhci     # provides USB 1.x support
 device ohci     # provides USB 1.x support
 device ehci     # provides USB 2.0 support
 device xhci     # provides USB 3.0 support
 device usb      # USB Bus (required)
 device umass    # Disks/Mass storage - Requires scbus and da

   For an ATAPI burner, make sure these options are present:

 device ata      # Legacy ATA/SATA controllers
 device scbus    # SCSI bus (required for ATA/SCSI)
 device pass     # Passthrough device (direct ATA/SCSI access)
 device cd       # needed for CD and DVD burners

  Note:

   On FreeBSD versions prior to 10.x, this line is also needed in the kernel
   configuration file if the burner is an ATAPI device:

 device atapicam

   Alternately, this driver can be loaded at boot time by adding the
   following line to /boot/loader.conf:

 atapicam_load="YES"

   This will require a reboot of the system as this driver can only be loaded
   at boot time.

   To verify that FreeBSD recognizes the device, run dmesg and look for an
   entry for the device. On systems prior to 10.x, the device name in the
   first line of the output will be acd0 instead of cd0.

 % dmesg | grep cd
 cd0 at ahcich1 bus 0 scbus1 target 0 lun 0
 cd0: <HL-DT-ST DVDRAM GU70N LT20> Removable CD-ROM SCSI-0 device
 cd0: Serial Number M3OD3S34152
 cd0: 150.000MB/s transfers (SATA 1.x, UDMA6, ATAPI 12bytes, PIO 8192bytes)
 cd0: Attempt to query device size failed: NOT READY, Medium not present - tray closed

  18.5.2. Burning a CD

   In FreeBSD, cdrecord can be used to burn CDs. This command is installed
   with the sysutils/cdrtools package or port.

   While cdrecord has many options, basic usage is simple. Specify the name
   of the ISO file to burn and, if the system has multiple burner devices,
   specify the name of the device to use:

 # cdrecord dev=device imagefile.iso

   To determine the device name of the burner, use -scanbus which might
   produce results like this:

 # cdrecord -scanbus
 ProDVD-ProBD-Clone 3.00 (amd64-unknown-freebsd10.0) Copyright (C) 1995-2010 Jo:rg Schilling
 Using libscg version 'schily-0.9'
 scsibus0:
         0,0,0     0) 'SEAGATE ' 'ST39236LW       ' '0004' Disk
         0,1,0     1) 'SEAGATE ' 'ST39173W        ' '5958' Disk
         0,2,0     2) *
         0,3,0     3) 'iomega  ' 'jaz 1GB         ' 'J.86' Removable Disk
         0,4,0     4) 'NEC     ' 'CD-ROM DRIVE:466' '1.26' Removable CD-ROM
         0,5,0     5) *
         0,6,0     6) *
         0,7,0     7) *
 scsibus1:
         1,0,0   100) *
         1,1,0   101) *
         1,2,0   102) *
         1,3,0   103) *
         1,4,0   104) *
         1,5,0   105) 'YAMAHA  ' 'CRW4260         ' '1.0q' Removable CD-ROM
         1,6,0   106) 'ARTEC   ' 'AM12S           ' '1.06' Scanner
         1,7,0   107) *

   Locate the entry for the CD burner and use the three numbers separated by
   commas as the value for dev. In this case, the Yamaha burner device is
   1,5,0, so the appropriate input to specify that device is dev=1,5,0. Refer
   to the manual page for cdrecord for other ways to specify this value and
   for information on writing audio tracks and controlling the write speed.

   Alternately, run the following command to get the device address of the
   burner:

 # camcontrol devlist
 <MATSHITA CDRW/DVD UJDA740 1.00>   at scbus1 target 0 lun 0 (cd0,pass0)

   Use the numeric values for scbus, target, and lun. For this example, 1,0,0
   is the device name to use.

  18.5.3. Writing Data to an ISO File System

   In order to produce a data CD, the data files that are going to make up
   the tracks on the CD must be prepared before they can be burned to the CD.
   In FreeBSD, sysutils/cdrtools installs mkisofs, which can be used to
   produce an ISO 9660 file system that is an image of a directory tree
   within a UNIX(R) file system. The simplest usage is to specify the name of
   the ISO file to create and the path to the files to place into the ISO
   9660 file system:

 # mkisofs -o imagefile.iso /path/to/tree

   This command maps the file names in the specified path to names that fit
   the limitations of the standard ISO 9660 file system, and will exclude
   files that do not meet the standard for ISO file systems.

   A number of options are available to overcome the restrictions imposed by
   the standard. In particular, -R enables the Rock Ridge extensions common
   to UNIX(R) systems and -J enables Joliet extensions used by Microsoft(R)
   systems.

   For CDs that are going to be used only on FreeBSD systems, -U can be used
   to disable all filename restrictions. When used with -R, it produces a
   file system image that is identical to the specified FreeBSD tree, even if
   it violates the ISO 9660 standard.

   The last option of general use is -b. This is used to specify the location
   of a boot image for use in producing an "El Torito" bootable CD. This
   option takes an argument which is the path to a boot image from the top of
   the tree being written to the CD. By default, mkisofs creates an ISO image
   in "floppy disk emulation" mode, and thus expects the boot image to be
   exactly 1200, 1440 or 2880 KB in size. Some boot loaders, like the one
   used by the FreeBSD distribution media, do not use emulation mode. In this
   case, -no-emul-boot should be used. So, if /tmp/myboot holds a bootable
   FreeBSD system with the boot image in /tmp/myboot/boot/cdboot, this
   command would produce /tmp/bootable.iso:

 # mkisofs -R -no-emul-boot -b boot/cdboot -o /tmp/bootable.iso /tmp/myboot

   The resulting ISO image can be mounted as a memory disk with:

 # mdconfig -a -t vnode -f /tmp/bootable.iso -u 0
 # mount -t cd9660 /dev/md0 /mnt

   One can then verify that /mnt and /tmp/myboot are identical.

   There are many other options available for mkisofs to fine-tune its
   behavior. Refer to mkisofs(8) for details.

  Note:

   It is possible to copy a data CD to an image file that is functionally
   equivalent to the image file created with mkisofs. To do so, use dd with
   the device name as the input file and the name of the ISO to create as the
   output file:

 # dd if=/dev/cd0 of=file.iso bs=2048

   The resulting image file can be burned to CD as described in
   Section 18.5.2, "Burning a CD".

  18.5.4. Using Data CDs

   Once an ISO has been burned to a CD, it can be mounted by specifying the
   file system type, the name of the device containing the CD, and an
   existing mount point:

 # mount -t cd9660 /dev/cd0 /mnt

   Since mount assumes that a file system is of type ufs, a Incorrect super
   block error will occur if -t cd9660 is not included when mounting a data
   CD.

   While any data CD can be mounted this way, disks with certain ISO 9660
   extensions might behave oddly. For example, Joliet disks store all
   filenames in two-byte Unicode characters. If some non-English characters
   show up as question marks, specify the local charset with -C. For more
   information, refer to mount_cd9660(8).

  Note:

   In order to do this character conversion with the help of -C, the kernel
   requires the cd9660_iconv.ko module to be loaded. This can be done either
   by adding this line to loader.conf:

 cd9660_iconv_load="YES"

   and then rebooting the machine, or by directly loading the module with
   kldload.

   Occasionally, Device not configured will be displayed when trying to mount
   a data CD. This usually means that the CD drive has not detected a disk in
   the tray, or that the drive is not visible on the bus. It can take a
   couple of seconds for a CD drive to detect media, so be patient.

   Sometimes, a SCSI CD drive may be missed because it did not have enough
   time to answer the bus reset. To resolve this, a custom kernel can be
   created which increases the default SCSI delay. Add the following option
   to the custom kernel configuration file and rebuild the kernel using the
   instructions in Section 8.5, "Building and Installing a Custom Kernel":

 options SCSI_DELAY=15000

   This tells the SCSI bus to pause 15 seconds during boot, to give the CD
   drive every possible chance to answer the bus reset.

  Note:

   It is possible to burn a file directly to CD, without creating an ISO 9660
   file system. This is known as burning a raw data CD and some people do
   this for backup purposes.

   This type of disk can not be mounted as a normal data CD. In order to
   retrieve the data burned to such a CD, the data must be read from the raw
   device node. For example, this command will extract a compressed tar file
   located on the second CD device into the current working directory:

 # tar xzvf /dev/cd1

   In order to mount a data CD, the data must be written using mkisofs.

  18.5.5. Duplicating Audio CDs

   To duplicate an audio CD, extract the audio data from the CD to a series
   of files, then write these files to a blank CD.

   Procedure 18.1, "Duplicating an Audio CD" describes how to duplicate and
   burn an audio CD. If the FreeBSD version is less than 10.0 and the device
   is ATAPI, the atapicam module must be first loaded using the instructions
   in Section 18.5.1, "Supported Devices".

   Procedure 18.1. Duplicating an Audio CD
    1. The sysutils/cdrtools package or port installs cdda2wav. This command
       can be used to extract all of the audio tracks, with each track
       written to a separate WAV file in the current working directory:

 % cdda2wav -vall -B -Owav

       A device name does not need to be specified if there is only one CD
       device on the system. Refer to the cdda2wav manual page for
       instructions on how to specify a device and to learn more about the
       other options available for this command.

    2. Use cdrecord to write the .wav files:

 % cdrecord -v dev=2,0 -dao -useinfo  *.wav

       Make sure that 2,0 is set appropriately, as described in
       Section 18.5.2, "Burning a CD".

18.6. Creating and Using DVD Media

   Contributed by Marc Fonvieille.
   With inputs from Andy Polyakov.

   Compared to the CD, the DVD is the next generation of optical media
   storage technology. The DVD can hold more data than any CD and is the
   standard for video publishing.

   Five physical recordable formats can be defined for a recordable DVD:

     * DVD-R: This was the first DVD recordable format available. The DVD-R
       standard is defined by the DVD Forum. This format is write once.

     * DVD-RW: This is the rewritable version of the DVD-R standard. A DVD-RW
       can be rewritten about 1000 times.

     * DVD-RAM: This is a rewritable format which can be seen as a removable
       hard drive. However, this media is not compatible with most DVD-ROM
       drives and DVD-Video players as only a few DVD writers support the
       DVD-RAM format. Refer to Section 18.6.8, "Using a DVD-RAM" for more
       information on DVD-RAM use.

     * DVD+RW: This is a rewritable format defined by the DVD+RW Alliance. A
       DVD+RW can be rewritten about 1000 times.

     * DVD+R: This format is the write once variation of the DVD+RW format.

   A single layer recordable DVD can hold up to 4,700,000,000 bytes which is
   actually 4.38 GB or 4485 MB as 1 kilobyte is 1024 bytes.

  Note:

   A distinction must be made between the physical media and the application.
   For example, a DVD-Video is a specific file layout that can be written on
   any recordable DVD physical media such as DVD-R, DVD+R, or DVD-RW. Before
   choosing the type of media, ensure that both the burner and the DVD-Video
   player are compatible with the media under consideration.

  18.6.1. Configuration

   To perform DVD recording, use growisofs(1). This command is part of the
   sysutils/dvd+rw-tools utilities which support all DVD media types.

   These tools use the SCSI subsystem to access the devices, therefore
   ATAPI/CAM support must be loaded or statically compiled into the kernel.
   This support is not needed if the burner uses the USB interface. Refer to
   Section 18.4, "USB Storage Devices" for more details on USB device
   configuration.

   DMA access must also be enabled for ATAPI devices, by adding the following
   line to /boot/loader.conf:

 hw.ata.atapi_dma="1"

   Before attempting to use dvd+rw-tools, consult the Hardware Compatibility
   Notes.

  Note:

   For a graphical user interface, consider using sysutils/k3b which provides
   a user friendly interface to growisofs(1) and many other burning tools.

  18.6.2. Burning Data DVDs

   Since growisofs(1) is a front-end to mkisofs, it will invoke mkisofs(8) to
   create the file system layout and perform the write on the DVD. This means
   that an image of the data does not need to be created before the burning
   process.

   To burn to a DVD+R or a DVD-R the data in /path/to/data, use the following
   command:

 # growisofs -dvd-compat -Z /dev/cd0 -J -R /path/to/data

   In this example, -J -R is passed to mkisofs(8) to create an ISO 9660 file
   system with Joliet and Rock Ridge extensions. Refer to mkisofs(8) for more
   details.

   For the initial session recording, -Z is used for both single and multiple
   sessions. Replace /dev/cd0, with the name of the DVD device. Using
   -dvd-compat indicates that the disk will be closed and that the recording
   will be unappendable. This should also provide better media compatibility
   with DVD-ROM drives.

   To burn a pre-mastered image, such as imagefile.iso, use:

 # growisofs -dvd-compat -Z /dev/cd0=imagefile.iso

   The write speed should be detected and automatically set according to the
   media and the drive being used. To force the write speed, use -speed=.
   Refer to growisofs(1) for example usage.

  Note:

   In order to support working files larger than 4.38GB, an UDF/ISO-9660
   hybrid file system must be created by passing -udf -iso-level 3 to
   mkisofs(8) and all related programs, such as growisofs(1). This is
   required only when creating an ISO image file or when writing files
   directly to a disk. Since a disk created this way must be mounted as an
   UDF file system with mount_udf(8), it will be usable only on an UDF aware
   operating system. Otherwise it will look as if it contains corrupted
   files.

   To create this type of ISO file:

 % mkisofs -R -J -udf -iso-level 3 -o imagefile.iso /path/to/data

   To burn files directly to a disk:

 # growisofs -dvd-compat -udf -iso-level 3 -Z /dev/cd0 -J -R /path/to/data

   When an ISO image already contains large files, no additional options are
   required for growisofs(1) to burn that image on a disk.

   Be sure to use an up-to-date version of sysutils/cdrtools, which contains
   mkisofs(8), as an older version may not contain large files support. If
   the latest version does not work, install sysutils/cdrtools-devel and read
   its mkisofs(8).

  18.6.3. Burning a DVD-Video

   A DVD-Video is a specific file layout based on the ISO 9660 and micro-UDF
   (M-UDF) specifications. Since DVD-Video presents a specific data structure
   hierarchy, a particular program such as multimedia/dvdauthor is needed to
   author the DVD.

   If an image of the DVD-Video file system already exists, it can be burned
   in the same way as any other image. If dvdauthor was used to make the DVD
   and the result is in /path/to/video, the following command should be used
   to burn the DVD-Video:

 # growisofs -Z /dev/cd0 -dvd-video /path/to/video

   -dvd-video is passed to mkisofs(8) to instruct it to create a DVD-Video
   file system layout. This option implies the -dvd-compat growisofs(1)
   option.

  18.6.4. Using a DVD+RW

   Unlike CD-RW, a virgin DVD+RW needs to be formatted before first use. It
   is recommended to let growisofs(1) take care of this automatically
   whenever appropriate. However, it is possible to use dvd+rw-format to
   format the DVD+RW:

 # dvd+rw-format /dev/cd0

   Only perform this operation once and keep in mind that only virgin DVD+RW
   medias need to be formatted. Once formatted, the DVD+RW can be burned as
   usual.

   To burn a totally new file system and not just append some data onto a
   DVD+RW, the media does not need to be blanked first. Instead, write over
   the previous recording like this:

 # growisofs -Z /dev/cd0 -J -R /path/to/newdata

   The DVD+RW format supports appending data to a previous recording. This
   operation consists of merging a new session to the existing one as it is
   not considered to be multi-session writing. growisofs(1) will grow the ISO
   9660 file system present on the media.

   For example, to append data to a DVD+RW, use the following:

 # growisofs -M /dev/cd0 -J -R /path/to/nextdata

   The same mkisofs(8) options used to burn the initial session should be
   used during next writes.

  Note:

   Use -dvd-compat for better media compatibility with DVD-ROM drives. When
   using DVD+RW, this option will not prevent the addition of data.

   To blank the media, use:

 # growisofs -Z /dev/cd0=/dev/zero

  18.6.5. Using a DVD-RW

   A DVD-RW accepts two disc formats: incremental sequential and restricted
   overwrite. By default, DVD-RW discs are in sequential format.

   A virgin DVD-RW can be directly written without being formatted. However,
   a non-virgin DVD-RW in sequential format needs to be blanked before
   writing a new initial session.

   To blank a DVD-RW in sequential mode:

 # dvd+rw-format -blank=full /dev/cd0

  Note:

   A full blanking using -blank=full will take about one hour on a 1x media.
   A fast blanking can be performed using -blank, if the DVD-RW will be
   recorded in Disk-At-Once (DAO) mode. To burn the DVD-RW in DAO mode, use
   the command:

 # growisofs -use-the-force-luke=dao -Z /dev/cd0=imagefile.iso

   Since growisofs(1) automatically attempts to detect fast blanked media and
   engage DAO write, -use-the-force-luke=dao should not be required.

   One should instead use restricted overwrite mode with any DVD-RW as this
   format is more flexible than the default of incremental sequential.

   To write data on a sequential DVD-RW, use the same instructions as for the
   other DVD formats:

 # growisofs -Z /dev/cd0 -J -R /path/to/data

   To append some data to a previous recording, use -M with growisofs(1).
   However, if data is appended on a DVD-RW in incremental sequential mode, a
   new session will be created on the disc and the result will be a
   multi-session disc.

   A DVD-RW in restricted overwrite format does not need to be blanked before
   a new initial session. Instead, overwrite the disc with -Z. It is also
   possible to grow an existing ISO 9660 file system written on the disc with
   -M. The result will be a one-session DVD.

   To put a DVD-RW in restricted overwrite format, the following command must
   be used:

 # dvd+rw-format /dev/cd0

   To change back to sequential format, use:

 # dvd+rw-format -blank=full /dev/cd0

  18.6.6. Multi-Session

   Few DVD-ROM drives support multi-session DVDs and most of the time only
   read the first session. DVD+R, DVD-R and DVD-RW in sequential format can
   accept multiple sessions. The notion of multiple sessions does not exist
   for the DVD+RW and the DVD-RW restricted overwrite formats.

   Using the following command after an initial non-closed session on a
   DVD+R, DVD-R, or DVD-RW in sequential format, will add a new session to
   the disc:

 # growisofs -M /dev/cd0 -J -R /path/to/nextdata

   Using this command with a DVD+RW or a DVD-RW in restricted overwrite mode
   will append data while merging the new session to the existing one. The
   result will be a single-session disc. Use this method to add data after an
   initial write on these types of media.

  Note:

   Since some space on the media is used between each session to mark the end
   and start of sessions, one should add sessions with a large amount of data
   to optimize media space. The number of sessions is limited to 154 for a
   DVD+R, about 2000 for a DVD-R, and 127 for a DVD+R Double Layer.

  18.6.7. For More Information

   To obtain more information about a DVD, use dvd+rw-mediainfo /dev/cd0
   while the disc in the specified drive.

   More information about dvd+rw-tools can be found in growisofs(1), on the
   dvd+rw-tools web site, and in the cdwrite mailing list archives.

  Note:

   When creating a problem report related to the use of dvd+rw-tools, always
   include the output of dvd+rw-mediainfo.

  18.6.8. Using a DVD-RAM

   DVD-RAM writers can use either a SCSI or ATAPI interface. For ATAPI
   devices, DMA access has to be enabled by adding the following line to
   /boot/loader.conf:

 hw.ata.atapi_dma="1"

   A DVD-RAM can be seen as a removable hard drive. Like any other hard
   drive, the DVD-RAM must be formatted before it can be used. In this
   example, the whole disk space will be formatted with a standard UFS2 file
   system:

 # dd if=/dev/zero of=/dev/acd0 bs=2k count=1
 # bsdlabel -Bw acd0
 # newfs /dev/acd0

   The DVD device, acd0, must be changed according to the configuration.

   Once the DVD-RAM has been formatted, it can be mounted as a normal hard
   drive:

 # mount /dev/acd0 /mnt

   Once mounted, the DVD-RAM will be both readable and writeable.

18.7. Creating and Using Floppy Disks

   This section explains how to format a 3.5 inch floppy disk in FreeBSD.

   Procedure 18.2. Steps to Format a Floppy

   A floppy disk needs to be low-level formatted before it can be used. This
   is usually done by the vendor, but formatting is a good way to check media
   integrity. To low-level format the floppy disk on FreeBSD, use
   fdformat(1). When using this utility, make note of any error messages, as
   these can help determine if the disk is good or bad.

    1. To format the floppy, insert a new 3.5 inch floppy disk into the first
       floppy drive and issue:

 # /usr/sbin/fdformat -f 1440 /dev/fd0

    2. After low-level formatting the disk, create a disk label as it is
       needed by the system to determine the size of the disk and its
       geometry. The supported geometry values are listed in /etc/disktab.

       To write the disk label, use bsdlabel(8):

 # /sbin/bsdlabel -B -w /dev/fd0 fd1440

    3. The floppy is now ready to be high-level formatted with a file system.
       The floppy's file system can be either UFS or FAT, where FAT is
       generally a better choice for floppies.

       To format the floppy with FAT, issue:

 # /sbin/newfs_msdos /dev/fd0

   The disk is now ready for use. To use the floppy, mount it with
   mount_msdosfs(8). One can also install and use emulators/mtools from the
   Ports Collection.

18.8. Backup Basics

   Implementing a backup plan is essential in order to have the ability to
   recover from disk failure, accidental file deletion, random file
   corruption, or complete machine destruction, including destruction of
   on-site backups.

   The backup type and schedule will vary, depending upon the importance of
   the data, the granularity needed for file restores, and the amount of
   acceptable downtime. Some possible backup techniques include:

     * Archives of the whole system, backed up onto permanent, off-site
       media. This provides protection against all of the problems listed
       above, but is slow and inconvenient to restore from, especially for
       non-privileged users.

     * File system snapshots, which are useful for restoring deleted files or
       previous versions of files.

     * Copies of whole file systems or disks which are synchronized with
       another system on the network using a scheduled net/rsync.

     * Hardware or software RAID, which minimizes or avoids downtime when a
       disk fails.

   Typically, a mix of backup techniques is used. For example, one could
   create a schedule to automate a weekly, full system backup that is stored
   off-site and to supplement this backup with hourly ZFS snapshots. In
   addition, one could make a manual backup of individual directories or
   files before making file edits or deletions.

   This section describes some of the utilities which can be used to create
   and manage backups on a FreeBSD system.

  18.8.1. File System Backups

   The traditional UNIX(R) programs for backing up a file system are dump(8),
   which creates the backup, and restore(8), which restores the backup. These
   utilities work at the disk block level, below the abstractions of the
   files, links, and directories that are created by file systems. Unlike
   other backup software, dump backs up an entire file system and is unable
   to backup only part of a file system or a directory tree that spans
   multiple file systems. Instead of writing files and directories, dump
   writes the raw data blocks that comprise files and directories.

  Note:

   If dump is used on the root directory, it will not back up /home, /usr or
   many other directories since these are typically mount points for other
   file systems or symbolic links into those file systems.

   When used to restore data, restore stores temporary files in /tmp/ by
   default. When using a recovery disk with a small /tmp, set TMPDIR to a
   directory with more free space in order for the restore to succeed.

   When using dump, be aware that some quirks remain from its early days in
   Version 6 of AT&T UNIX(R),circa 1975. The default parameters assume a
   backup to a 9-track tape, rather than to another type of media or to the
   high-density tapes available today. These defaults must be overridden on
   the command line.

   It is possible to backup a file system across the network to a another
   system or to a tape drive attached to another computer. While the rdump(8)
   and rrestore(8) utilities can be used for this purpose, they are not
   considered to be secure.

   Instead, one can use dump and restore in a more secure fashion over an SSH
   connection. This example creates a full, compressed backup of /usr and
   sends the backup file to the specified host over a SSH connection.

   Example 18.1. Using dump over ssh

 # /sbin/dump -0uan -f - /usr | gzip -2 | ssh -c blowfish \
           targetuser@targetmachine.example.com dd of=/mybigfiles/dump-usr-l0.gz

   This example sets RSH in order to write the backup to a tape drive on a
   remote system over a SSH connection:

   Example 18.2. Using dump over ssh with RSH Set

 # env RSH=/usr/bin/ssh /sbin/dump -0uan -f targetuser@targetmachine.example.com:/dev/sa0 /usr

  18.8.2. Directory Backups

   Several built-in utilities are available for backing up and restoring
   specified files and directories as needed.

   A good choice for making a backup of all of the files in a directory is
   tar(1). This utility dates back to Version 6 of AT&T UNIX(R) and by
   default assumes a recursive backup to a local tape device. Switches can be
   used to instead specify the name of a backup file.

   This example creates a compressed backup of the current directory and
   saves it to /tmp/mybackup.tgz. When creating a backup file, make sure that
   the backup is not saved to the same directory that is being backed up.

   Example 18.3. Backing Up the Current Directory with tar

 # tar czvf /tmp/mybackup.tgz .

   To restore the entire backup, cd into the directory to restore into and
   specify the name of the backup. Note that this will overwrite any newer
   versions of files in the restore directory. When in doubt, restore to a
   temporary directory or specify the name of the file within the backup to
   restore.

   Example 18.4. Restoring Up the Current Directory with tar

 # tar xzvf /tmp/mybackup.tgz

   There are dozens of available switches which are described in tar(1). This
   utility also supports the use of exclude patterns to specify which files
   should not be included when backing up the specified directory or
   restoring files from a backup.

   To create a backup using a specified list of files and directories,
   cpio(1) is a good choice. Unlike tar, cpio does not know how to walk the
   directory tree and it must be provided the list of files to backup.

   For example, a list of files can be created using ls or find. This example
   creates a recursive listing of the current directory which is then piped
   to cpio in order to create an output backup file named /tmp/mybackup.cpio.

   Example 18.5. Using ls and cpio to Make a Recursive Backup of the Current
   Directory

 # ls -R | cpio -ovF /tmp/mybackup.cpio

   A backup utility which tries to bridge the features provided by tar and
   cpio is pax(1). Over the years, the various versions of tar and cpio
   became slightly incompatible. POSIX(R) created pax which attempts to read
   and write many of the various cpio and tar formats, plus new formats of
   its own.

   The pax equivalent to the previous examples would be:

   Example 18.6. Backing Up the Current Directory with pax

 # pax -wf /tmp/mybackup.pax .

  18.8.3. Using Data Tapes for Backups

   While tape technology has continued to evolve, modern backup systems tend
   to combine off-site backups with local removable media. FreeBSD supports
   any tape drive that uses SCSI, such as LTO or DAT. There is limited
   support for SATA and USB tape drives.

   For SCSI tape devices, FreeBSD uses the sa(4) driver and the /dev/sa0,
   /dev/nsa0, and /dev/esa0 devices. The physical device name is /dev/sa0.
   When /dev/nsa0 is used, the backup application will not rewind the tape
   after writing a file, which allows writing more than one file to a tape.
   Using /dev/esa0 ejects the tape after the device is closed.

   In FreeBSD, mt is used to control operations of the tape drive, such as
   seeking through files on a tape or writing tape control marks to the tape.
   For example, the first three files on a tape can be preserved by skipping
   past them before writing a new file:

 # mt -f /dev/nsa0 fsf 3

   This utility supports many operations. Refer to mt(1) for details.

   To write a single file to tape using tar, specify the name of the tape
   device and the file to backup:

 # tar cvf /dev/sa0 file

   To recover files from a tar archive on tape into the current directory:

 # tar xvf /dev/sa0

   To backup a UFS file system, use dump. This examples backs up /usr without
   rewinding the tape when finished:

 # dump -0aL -b64 -f /dev/nsa0 /usr

   To interactively restore files from a dump file on tape into the current
   directory:

 # restore -i -f /dev/nsa0

  18.8.4. Third-Party Backup Utilities

   The FreeBSD Ports Collection provides many third-party utilities which can
   be used to schedule the creation of backups, simplify tape backup, and
   make backups easier and more convenient. Many of these applications are
   client/server based and can be used to automate the backups of a single
   system or all of the computers in a network.

   Popular utilities include Amanda, Bacula, rsync, and duplicity.

  18.8.5. Emergency Recovery

   In addition to regular backups, it is recommended to perform the following
   steps as part of an emergency preparedness plan.

   Create a print copy of the output of the following commands:

     * gpart show

     * more /etc/fstab

     * dmesg

   Store this printout and a copy of the installation media in a secure
   location. Should an emergency restore be needed, boot into the
   installation media and select Live CD to access a rescue shell. This
   rescue mode can be used to view the current state of the system, and if
   needed, to reformat disks and restore data from backups.

  Note:

   The installation media for FreeBSD/i386 11.2-RELEASE does not include a
   rescue shell. For this version, instead download and burn a Livefs CD
   image from
   ftp://ftp.FreeBSD.org/pub/FreeBSD/releases/i386/ISO-IMAGES/11.2/FreeBSD-11.2-RELEASE-i386-livefs.iso.

   Next, test the rescue shell and the backups. Make notes of the procedure.
   Store these notes with the media, the printouts, and the backups. These
   notes may prevent the inadvertent destruction of the backups while under
   the stress of performing an emergency recovery.

   For an added measure of security, store the latest backup at a remote
   location which is physically separated from the computers and disk drives
   by a significant distance.

18.9. Memory Disks

   Reorganized and enhanced by Marc Fonvieille.

   In addition to physical disks, FreeBSD also supports the creation and use
   of memory disks. One possible use for a memory disk is to access the
   contents of an ISO file system without the overhead of first burning it to
   a CD or DVD, then mounting the CD/DVD media.

   In FreeBSD, the md(4) driver is used to provide support for memory disks.
   The GENERIC kernel includes this driver. When using a custom kernel
   configuration file, ensure it includes this line:

 device md

  18.9.1. Attaching and Detaching Existing Images

   To mount an existing file system image, use mdconfig to specify the name
   of the ISO file and a free unit number. Then, refer to that unit number to
   mount it on an existing mount point. Once mounted, the files in the ISO
   will appear in the mount point. This example attaches diskimage.iso to the
   memory device /dev/md0 then mounts that memory device on /mnt:

 # mdconfig -f diskimage.iso -u 0
 # mount -t cd9660 /dev/md0 /mnt

   Notice that -t cd9660 was used to mount an ISO format. If a unit number is
   not specified with -u, mdconfig will automatically allocate an unused
   memory device and output the name of the allocated unit, such as md4.
   Refer to mdconfig(8) for more details about this command and its options.

   When a memory disk is no longer in use, its resources should be released
   back to the system. First, unmount the file system, then use mdconfig to
   detach the disk from the system and release its resources. To continue
   this example:

 # umount /mnt
 # mdconfig -d -u 0

   To determine if any memory disks are still attached to the system, type
   mdconfig -l.

  18.9.2. Creating a File- or Memory-Backed Memory Disk

   FreeBSD also supports memory disks where the storage to use is allocated
   from either a hard disk or an area of memory. The first method is commonly
   referred to as a file-backed file system and the second method as a
   memory-backed file system. Both types can be created using mdconfig.

   To create a new memory-backed file system, specify a type of swap and the
   size of the memory disk to create. Then, format the memory disk with a
   file system and mount as usual. This example creates a 5M memory disk on
   unit 1. That memory disk is then formatted with the UFS file system before
   it is mounted:

 # mdconfig -a -t swap -s 5m -u 1
 # newfs -U md1
 /dev/md1: 5.0MB (10240 sectors) block size 16384, fragment size 2048
         using 4 cylinder groups of 1.27MB, 81 blks, 192 inodes.
         with soft updates
 super-block backups (for fsck -b #) at:
  160, 2752, 5344, 7936
 # mount /dev/md1 /mnt
 # df /mnt
 Filesystem 1K-blocks Used Avail Capacity  Mounted on
 /dev/md1        4718    4  4338     0%    /mnt

   To create a new file-backed memory disk, first allocate an area of disk to
   use. This example creates an empty 5MB file named newimage:

 # dd if=/dev/zero of=newimage bs=1k count=5k
 5120+0 records in
 5120+0 records out

   Next, attach that file to a memory disk, label the memory disk and format
   it with the UFS file system, mount the memory disk, and verify the size of
   the file-backed disk:

 # mdconfig -f newimage -u 0
 # bsdlabel -w md0 auto
 # newfs -U md0a
 /dev/md0a: 5.0MB (10224 sectors) block size 16384, fragment size 2048
         using 4 cylinder groups of 1.25MB, 80 blks, 192 inodes.
 super-block backups (for fsck -b #) at:
  160, 2720, 5280, 7840
 # mount /dev/md0a /mnt
 # df /mnt
 Filesystem 1K-blocks Used Avail Capacity  Mounted on
 /dev/md0a       4710    4  4330     0%    /mnt

   It takes several commands to create a file- or memory-backed file system
   using mdconfig. FreeBSD also comes with mdmfs which automatically
   configures a memory disk, formats it with the UFS file system, and mounts
   it. For example, after creating newimage with dd, this one command is
   equivalent to running the bsdlabel, newfs, and mount commands shown above:

 # mdmfs -F newimage -s 5m md0 /mnt

   To instead create a new memory-based memory disk with mdmfs, use this one
   command:

 # mdmfs -s 5m md1 /mnt

   If the unit number is not specified, mdmfs will automatically select an
   unused memory device. For more details about mdmfs, refer to mdmfs(8).

18.10. File System Snapshots

   Contributed by Tom Rhodes.

   FreeBSD offers a feature in conjunction with Soft Updates: file system
   snapshots.

   UFS snapshots allow a user to create images of specified file systems, and
   treat them as a file. Snapshot files must be created in the file system
   that the action is performed on, and a user may create no more than 20
   snapshots per file system. Active snapshots are recorded in the superblock
   so they are persistent across unmount and remount operations along with
   system reboots. When a snapshot is no longer required, it can be removed
   using rm(1). While snapshots may be removed in any order, all the used
   space may not be acquired because another snapshot will possibly claim
   some of the released blocks.

   The un-alterable snapshot file flag is set by mksnap_ffs(8) after initial
   creation of a snapshot file. unlink(1) makes an exception for snapshot
   files since it allows them to be removed.

   Snapshots are created using mount(8). To place a snapshot of /var in the
   file /var/snapshot/snap, use the following command:

 # mount -u -o snapshot /var/snapshot/snap /var

   Alternatively, use mksnap_ffs(8) to create the snapshot:

 # mksnap_ffs /var /var/snapshot/snap

   One can find snapshot files on a file system, such as /var, using find(1):

 # find /var -flags snapshot

   Once a snapshot has been created, it has several uses:

     * Some administrators will use a snapshot file for backup purposes,
       because the snapshot can be transferred to CDs or tape.

     * The file system integrity checker, fsck(8), may be run on the
       snapshot. Assuming that the file system was clean when it was mounted,
       this should always provide a clean and unchanging result.

     * Running dump(8) on the snapshot will produce a dump file that is
       consistent with the file system and the timestamp of the snapshot.
       dump(8) can also take a snapshot, create a dump image, and then remove
       the snapshot in one command by using -L.

     * The snapshot can be mounted as a frozen image of the file system. To
       mount(8) the snapshot /var/snapshot/snap run:

 # mdconfig -a -t vnode -o readonly -f /var/snapshot/snap -u 4
 # mount -r /dev/md4 /mnt

   The frozen /var is now available through /mnt. Everything will initially
   be in the same state it was during the snapshot creation time. The only
   exception is that any earlier snapshots will appear as zero length files.
   To unmount the snapshot, use:

 # umount /mnt
 # mdconfig -d -u 4

   For more information about softupdates and file system snapshots,
   including technical papers, visit Marshall Kirk McKusick's website at
   http://www.mckusick.com/.

18.11. Disk Quotas

   Disk quotas can be used to limit the amount of disk space or the number of
   files a user or members of a group may allocate on a per-file system
   basis. This prevents one user or group of users from consuming all of the
   available disk space.

   This section describes how to configure disk quotas for the UFS file
   system. To configure quotas on the ZFS file system, refer to
   Section 20.4.8, "Dataset, User, and Group Quotas"

  18.11.1. Enabling Disk Quotas

   To determine if the FreeBSD kernel provides support for disk quotas:

 % sysctl kern.features.ufs_quota
 kern.features.ufs_quota: 1

   In this example, the 1 indicates quota support. If the value is instead 0,
   add the following line to a custom kernel configuration file and rebuild
   the kernel using the instructions in Chapter 8, Configuring the FreeBSD
   Kernel:

 options QUOTA

   Next, enable disk quotas in /etc/rc.conf:

 quota_enable="YES"

   Normally on bootup, the quota integrity of each file system is checked by
   quotacheck(8). This program insures that the data in the quota database
   properly reflects the data on the file system. This is a time consuming
   process that will significantly affect the time the system takes to boot.
   To skip this step, add this variable to /etc/rc.conf:

 check_quotas="NO"

   Finally, edit /etc/fstab to enable disk quotas on a per-file system basis.
   To enable per-user quotas on a file system, add userquota to the options
   field in the /etc/fstab entry for the file system to enable quotas on. For
   example:

 /dev/da1s2g   /home    ufs rw,userquota 1 2

   To enable group quotas, use groupquota instead. To enable both user and
   group quotas, separate the options with a comma:

 /dev/da1s2g    /home    ufs rw,userquota,groupquota 1 2

   By default, quota files are stored in the root directory of the file
   system as quota.user and quota.group. Refer to fstab(5) for more
   information. Specifying an alternate location for the quota files is not
   recommended.

   Once the configuration is complete, reboot the system and /etc/rc will
   automatically run the appropriate commands to create the initial quota
   files for all of the quotas enabled in /etc/fstab.

   In the normal course of operations, there should be no need to manually
   run quotacheck(8), quotaon(8), or quotaoff(8). However, one should read
   these manual pages to be familiar with their operation.

  18.11.2. Setting Quota Limits

   To verify that quotas are enabled, run:

 # quota -v

   There should be a one line summary of disk usage and current quota limits
   for each file system that quotas are enabled on.

   The system is now ready to be assigned quota limits with edquota.

   Several options are available to enforce limits on the amount of disk
   space a user or group may allocate, and how many files they may create.
   Allocations can be limited based on disk space (block quotas), number of
   files (inode quotas), or a combination of both. Each limit is further
   broken down into two categories: hard and soft limits.

   A hard limit may not be exceeded. Once a user reaches a hard limit, no
   further allocations can be made on that file system by that user. For
   example, if the user has a hard limit of 500 kbytes on a file system and
   is currently using 490 kbytes, the user can only allocate an additional 10
   kbytes. Attempting to allocate an additional 11 kbytes will fail.

   Soft limits can be exceeded for a limited amount of time, known as the
   grace period, which is one week by default. If a user stays over their
   limit longer than the grace period, the soft limit turns into a hard limit
   and no further allocations are allowed. When the user drops back below the
   soft limit, the grace period is reset.

   In the following example, the quota for the test account is being edited.
   When edquota is invoked, the editor specified by EDITOR is opened in order
   to edit the quota limits. The default editor is set to vi.

 # edquota -u test
 Quotas for user test:
 /usr: kbytes in use: 65, limits (soft = 50, hard = 75)
         inodes in use: 7, limits (soft = 50, hard = 60)
 /usr/var: kbytes in use: 0, limits (soft = 50, hard = 75)
         inodes in use: 0, limits (soft = 50, hard = 60)

   There are normally two lines for each file system that has quotas enabled.
   One line represents the block limits and the other represents the inode
   limits. Change the value to modify the quota limit. For example, to raise
   the block limit on /usr to a soft limit of 500 and a hard limit of 600,
   change the values in that line as follows:

 /usr: kbytes in use: 65, limits (soft = 500, hard = 600)

   The new quota limits take effect upon exiting the editor.

   Sometimes it is desirable to set quota limits on a range of users. This
   can be done by first assigning the desired quota limit to a user. Then,
   use -p to duplicate that quota to a specified range of user IDs (UIDs).
   The following command will duplicate those quota limits for UIDs 10,000
   through 19,999:

 # edquota -p test 10000-19999

   For more information, refer to edquota(8).

  18.11.3. Checking Quota Limits and Disk Usage

   To check individual user or group quotas and disk usage, use quota(1). A
   user may only examine their own quota and the quota of a group they are a
   member of. Only the superuser may view all user and group quotas. To get a
   summary of all quotas and disk usage for file systems with quotas enabled,
   use repquota(8).

   Normally, file systems that the user is not using any disk space on will
   not show in the output of quota, even if the user has a quota limit
   assigned for that file system. Use -v to display those file systems. The
   following is sample output from quota -v for a user that has quota limits
   on two file systems.

 Disk quotas for user test (uid 1002):
      Filesystem  usage    quota   limit   grace   files   quota   limit   grace
            /usr      65*     50      75   5days       7      50      60
        /usr/var       0      50      75               0      50      60

   In this example, the user is currently 15 kbytes over the soft limit of 50
   kbytes on /usr and has 5 days of grace period left. The asterisk *
   indicates that the user is currently over the quota limit.

  18.11.4. Quotas over NFS

   Quotas are enforced by the quota subsystem on the NFS server. The
   rpc.rquotad(8) daemon makes quota information available to quota on NFS
   clients, allowing users on those machines to see their quota statistics.

   On the NFS server, enable rpc.rquotad by removing the # from this line in
   /etc/inetd.conf:

 rquotad/1      dgram rpc/udp wait root /usr/libexec/rpc.rquotad rpc.rquotad

   Then, restart inetd:

 # service inetd restart

18.12. Encrypting Disk Partitions

   Contributed by Lucky Green.

   FreeBSD offers excellent online protections against unauthorized data
   access. File permissions and Mandatory Access Control (MAC) help prevent
   unauthorized users from accessing data while the operating system is
   active and the computer is powered up. However, the permissions enforced
   by the operating system are irrelevant if an attacker has physical access
   to a computer and can move the computer's hard drive to another system to
   copy and analyze the data.

   Regardless of how an attacker may have come into possession of a hard
   drive or powered-down computer, the GEOM-based cryptographic subsystems
   built into FreeBSD are able to protect the data on the computer's file
   systems against even highly-motivated attackers with significant
   resources. Unlike encryption methods that encrypt individual files, the
   built-in gbde and geli utilities can be used to transparently encrypt
   entire file systems. No cleartext ever touches the hard drive's platter.

   This chapter demonstrates how to create an encrypted file system on
   FreeBSD. It first demonstrates the process using gbde and then
   demonstrates the same example using geli.

  18.12.1. Disk Encryption with gbde

   The objective of the gbde(4) facility is to provide a formidable challenge
   for an attacker to gain access to the contents of a cold storage device.
   However, if the computer is compromised while up and running and the
   storage device is actively attached, or the attacker has access to a valid
   passphrase, it offers no protection to the contents of the storage device.
   Thus, it is important to provide physical security while the system is
   running and to protect the passphrase used by the encryption mechanism.

   This facility provides several barriers to protect the data stored in each
   disk sector. It encrypts the contents of a disk sector using 128-bit AES
   in CBC mode. Each sector on the disk is encrypted with a different AES
   key. For more information on the cryptographic design, including how the
   sector keys are derived from the user-supplied passphrase, refer to
   gbde(4).

   FreeBSD provides a kernel module for gbde which can be loaded with this
   command:

 # kldload geom_bde

   If using a custom kernel configuration file, ensure it contains this line:

   options GEOM_BDE

   The following example demonstrates adding a new hard drive to a system
   that will hold a single encrypted partition that will be mounted as
   /private.

   Procedure 18.3. Encrypting a Partition with gbde
    1. Add the New Hard Drive

       Install the new drive to the system as explained in Section 18.2,
       "Adding Disks". For the purposes of this example, a new hard drive
       partition has been added as /dev/ad4s1c and /dev/ad0s1* represents the
       existing standard FreeBSD partitions.

 # ls /dev/ad*
 /dev/ad0        /dev/ad0s1b     /dev/ad0s1e     /dev/ad4s1
 /dev/ad0s1      /dev/ad0s1c     /dev/ad0s1f     /dev/ad4s1c
 /dev/ad0s1a     /dev/ad0s1d     /dev/ad4

    2. Create a Directory to Hold gbde Lock Files

 # mkdir /etc/gbde

       The gbde lock file contains information that gbde requires to access
       encrypted partitions. Without access to the lock file, gbde will not
       be able to decrypt the data contained in the encrypted partition
       without significant manual intervention which is not supported by the
       software. Each encrypted partition uses a separate lock file.

    3. Initialize the gbde Partition

       A gbde partition must be initialized before it can be used. This
       initialization needs to be performed only once. This command will open
       the default editor, in order to set various configuration options in a
       template. For use with the UFS file system, set the sector_size to
       2048:

 # gbde init /dev/ad4s1c -i -L /etc/gbde/ad4s1c.lock
 # $FreeBSD: src/sbin/gbde/template.txt,v 1.1.36.1 2009/08/03 08:13:06 kensmith Exp $
 #
 # Sector size is the smallest unit of data which can be read or written.
 # Making it too small decreases performance and decreases available space.
 # Making it too large may prevent filesystems from working.  512 is the
 # minimum and always safe.  For UFS, use the fragment size
 #
 sector_size     =       2048
 [...]

       Once the edit is saved, the user will be asked twice to type the
       passphrase used to secure the data. The passphrase must be the same
       both times. The ability of gbde to protect data depends entirely on
       the quality of the passphrase. For tips on how to select a secure
       passphrase that is easy to remember, see
       http://world.std.com/~reinhold/diceware.htm.

       This initialization creates a lock file for the gbde partition. In
       this example, it is stored as /etc/gbde/ad4s1c.lock. Lock files must
       end in ".lock" in order to be correctly detected by the /etc/rc.d/gbde
       start up script.

  Caution:

       Lock files must be backed up together with the contents of any
       encrypted partitions. Without the lock file, the legitimate owner will
       be unable to access the data on the encrypted partition.

    4. Attach the Encrypted Partition to the Kernel

 # gbde attach /dev/ad4s1c -l /etc/gbde/ad4s1c.lock

       This command will prompt to input the passphrase that was selected
       during the initialization of the encrypted partition. The new
       encrypted device will appear in /dev as /dev/device_name.bde:

 # ls /dev/ad*
 /dev/ad0        /dev/ad0s1b     /dev/ad0s1e     /dev/ad4s1
 /dev/ad0s1      /dev/ad0s1c     /dev/ad0s1f     /dev/ad4s1c
 /dev/ad0s1a     /dev/ad0s1d     /dev/ad4        /dev/ad4s1c.bde

    5. Create a File System on the Encrypted Device

       Once the encrypted device has been attached to the kernel, a file
       system can be created on the device. This example creates a UFS file
       system with soft updates enabled. Be sure to specify the partition
       which has a *.bde extension:

 # newfs -U /dev/ad4s1c.bde

    6. Mount the Encrypted Partition

       Create a mount point and mount the encrypted file system:

 # mkdir /private
 # mount /dev/ad4s1c.bde /private

    7. Verify That the Encrypted File System is Available

       The encrypted file system should now be visible and available for use:

 % df -H
 Filesystem        Size   Used  Avail Capacity  Mounted on
 /dev/ad0s1a      1037M    72M   883M     8%    /
 /devfs            1.0K   1.0K     0B   100%    /dev
 /dev/ad0s1f       8.1G    55K   7.5G     0%    /home
 /dev/ad0s1e      1037M   1.1M   953M     0%    /tmp
 /dev/ad0s1d       6.1G   1.9G   3.7G    35%    /usr
 /dev/ad4s1c.bde   150G   4.1K   138G     0%    /private

   After each boot, any encrypted file systems must be manually re-attached
   to the kernel, checked for errors, and mounted, before the file systems
   can be used. To configure these steps, add the following lines to
   /etc/rc.conf:

 gbde_autoattach_all="YES"
 gbde_devices="ad4s1c"
 gbde_lockdir="/etc/gbde"

   This requires that the passphrase be entered at the console at boot time.
   After typing the correct passphrase, the encrypted partition will be
   mounted automatically. Additional gbde boot options are available and
   listed in rc.conf(5).

  Note:

   sysinstall is incompatible with gbde-encrypted devices. All *.bde devices
   must be detached from the kernel before starting sysinstall or it will
   crash during its initial probing for devices. To detach the encrypted
   device used in the example, use the following command:

 # gbde detach /dev/ad4s1c

  18.12.2. Disk Encryption with geli

   Contributed by Daniel Gerzo.

   An alternative cryptographic GEOM class is available using geli. This
   control utility adds some features and uses a different scheme for doing
   cryptographic work. It provides the following features:

     * Utilizes the crypto(9) framework and automatically uses cryptographic
       hardware when it is available.

     * Supports multiple cryptographic algorithms such as AES, Blowfish, and
       3DES.

     * Allows the root partition to be encrypted. The passphrase used to
       access the encrypted root partition will be requested during system
       boot.

     * Allows the use of two independent keys.

     * It is fast as it performs simple sector-to-sector encryption.

     * Allows backup and restore of master keys. If a user destroys their
       keys, it is still possible to get access to the data by restoring keys
       from the backup.

     * Allows a disk to attach with a random, one-time key which is useful
       for swap partitions and temporary file systems.

   More features and usage examples can be found in geli(8).

   The following example describes how to generate a key file which will be
   used as part of the master key for the encrypted provider mounted under
   /private. The key file will provide some random data used to encrypt the
   master key. The master key will also be protected by a passphrase. The
   provider's sector size will be 4kB. The example describes how to attach to
   the geli provider, create a file system on it, mount it, work with it, and
   finally, how to detach it.

   Procedure 18.4. Encrypting a Partition with geli
    1. Load geli Support

       Support for geli is available as a loadable kernel module. To
       configure the system to automatically load the module at boot time,
       add the following line to /boot/loader.conf:

 geom_eli_load="YES"

       To load the kernel module now:

 # kldload geom_eli

       For a custom kernel, ensure the kernel configuration file contains
       these lines:

 options GEOM_ELI
 device crypto

    2. Generate the Master Key

       The following commands generate a master key that all data will be
       encrypted with. This key can never be changed. Rather than using it
       directly, it is encrypted with one or more user keys. The user keys
       are made up of an optional combination of random bytes from a file,
       /root/da2.key, and/or a passphrase. In this case, the data source for
       the key file is /dev/random. This command also configures the sector
       size of the provider (/dev/da2.eli) as 4kB, for better performance:

 # dd if=/dev/random of=/root/da2.key bs=64 count=1
 # geli init -K /root/da2.key -s 4096 /dev/da2
 Enter new passphrase:
 Reenter new passphrase:

       It is not mandatory to use both a passphrase and a key file as either
       method of securing the master key can be used in isolation.

       If the key file is given as "-", standard input will be used. For
       example, this command generates three key files:

 # cat keyfile1 keyfile2 keyfile3 | geli init -K - /dev/da2

    3. Attach the Provider with the Generated Key

       To attach the provider, specify the key file, the name of the disk,
       and the passphrase:

 # geli attach -k /root/da2.key /dev/da2
 Enter passphrase:

       This creates a new device with an .eli extension:

 # ls /dev/da2*
 /dev/da2  /dev/da2.eli

    4. Create the New File System

       Next, format the device with the UFS file system and mount it on an
       existing mount point:

 # dd if=/dev/random of=/dev/da2.eli bs=1m
 # newfs /dev/da2.eli
 # mount /dev/da2.eli /private

       The encrypted file system should now be available for use:

 # df -H
 Filesystem     Size   Used  Avail Capacity  Mounted on
 /dev/ad0s1a    248M    89M   139M    38%    /
 /devfs         1.0K   1.0K     0B   100%    /dev
 /dev/ad0s1f    7.7G   2.3G   4.9G    32%    /usr
 /dev/ad0s1d    989M   1.5M   909M     0%    /tmp
 /dev/ad0s1e    3.9G   1.3G   2.3G    35%    /var
 /dev/da2.eli   150G   4.1K   138G     0%    /private

   Once the work on the encrypted partition is done, and the /private
   partition is no longer needed, it is prudent to put the device into cold
   storage by unmounting and detaching the geli encrypted partition from the
   kernel:

 # umount /private
 # geli detach da2.eli

   An rc.d script is provided to simplify the mounting of geli-encrypted
   devices at boot time. For this example, add these lines to /etc/rc.conf:

 geli_devices="da2"
 geli_da2_flags="-k /root/da2.key"

   This configures /dev/da2 as a geli provider with a master key of
   /root/da2.key. The system will automatically detach the provider from the
   kernel before the system shuts down. During the startup process, the
   script will prompt for the passphrase before attaching the provider. Other
   kernel messages might be shown before and after the password prompt. If
   the boot process seems to stall, look carefully for the password prompt
   among the other messages. Once the correct passphrase is entered, the
   provider is attached. The file system is then mounted, typically by an
   entry in /etc/fstab. Refer to Section 3.7, "Mounting and Unmounting File
   Systems" for instructions on how to configure a file system to mount at
   boot time.

18.13. Encrypting Swap

   Written by Christian Brueffer.

   Like the encryption of disk partitions, encryption of swap space is used
   to protect sensitive information. Consider an application that deals with
   passwords. As long as these passwords stay in physical memory, they are
   not written to disk and will be cleared after a reboot. However, if
   FreeBSD starts swapping out memory pages to free space, the passwords may
   be written to the disk unencrypted. Encrypting swap space can be a
   solution for this scenario.

   This section demonstrates how to configure an encrypted swap partition
   using gbde(8) or geli(8) encryption. It assumes that /dev/ada0s1b is the
   swap partition.

  18.13.1. Configuring Encrypted Swap

   Swap partitions are not encrypted by default and should be cleared of any
   sensitive data before continuing. To overwrite the current swap partition
   with random garbage, execute the following command:

 # dd if=/dev/random of=/dev/ada0s1b bs=1m

   To encrypt the swap partition using gbde(8), add the .bde suffix to the
   swap line in /etc/fstab:

 # Device                Mountpoint      FStype  Options         Dump    Pass#
 /dev/ada0s1b.bde        none            swap    sw              0       0

   To instead encrypt the swap partition using geli(8), use the .eli suffix:

 # Device                Mountpoint      FStype  Options         Dump    Pass#
 /dev/ada0s1b.eli        none            swap    sw              0       0

   By default, geli(8) uses the AES algorithm with a key length of 128 bits.
   Normally the default settings will suffice. If desired, these defaults can
   be altered in the options field in /etc/fstab. The possible flags are:

   aalgo

           Data integrity verification algorithm used to ensure that the
           encrypted data has not been tampered with. See geli(8) for a list
           of supported algorithms.

   ealgo

           Encryption algorithm used to protect the data. See geli(8) for a
           list of supported algorithms.

   keylen

           The length of the key used for the encryption algorithm. See
           geli(8) for the key lengths that are supported by each encryption
           algorithm.

   sectorsize

           The size of the blocks data is broken into before it is encrypted.
           Larger sector sizes increase performance at the cost of higher
           storage overhead. The recommended size is 4096 bytes.

   This example configures an encrypted swap partition using the Blowfish
   algorithm with a key length of 128 bits and a sectorsize of 4 kilobytes:

 # Device                Mountpoint      FStype  Options                         Dump    Pass#
 /dev/ada0s1b.eli        none            swap    sw,ealgo=blowfish,keylen=128,sectorsize=4096    0       0

  18.13.2. Encrypted Swap Verification

   Once the system has rebooted, proper operation of the encrypted swap can
   be verified using swapinfo.

   If gbde(8) is being used:

 % swapinfo
 Device          1K-blocks     Used    Avail Capacity
 /dev/ada0s1b.bde   542720        0   542720     0%

   If geli(8) is being used:

 % swapinfo
 Device          1K-blocks     Used    Avail Capacity
 /dev/ada0s1b.eli   542720        0   542720     0%

18.14. Highly Available Storage (HAST)

   Contributed by Daniel Gerzo.
   With inputs from Freddie Cash, Pawel Jakub Dawidek, Michael W. Lucas and
   Viktor Petersson.

   High availability is one of the main requirements in serious business
   applications and highly-available storage is a key component in such
   environments. In FreeBSD, the Highly Available STorage (HAST) framework
   allows transparent storage of the same data across several physically
   separated machines connected by a TCP/IP network. HAST can be understood
   as a network-based RAID1 (mirror), and is similar to the DRBD(R) storage
   system used in the GNU/Linux(R) platform. In combination with other
   high-availability features of FreeBSD like CARP, HAST makes it possible to
   build a highly-available storage cluster that is resistant to hardware
   failures.

   The following are the main features of HAST:

     * Can be used to mask I/O errors on local hard drives.

     * File system agnostic as it works with any file system supported by
       FreeBSD.

     * Efficient and quick resynchronization as only the blocks that were
       modified during the downtime of a node are synchronized.

     * Can be used in an already deployed environment to add additional
       redundancy.

     * Together with CARP, Heartbeat, or other tools, it can be used to build
       a robust and durable storage system.

   After reading this section, you will know:

     * What HAST is, how it works, and which features it provides.

     * How to set up and use HAST on FreeBSD.

     * How to integrate CARP and devd(8) to build a robust storage system.

   Before reading this section, you should:

     * Understand UNIX(R) and FreeBSD basics (Chapter 3, FreeBSD Basics).

     * Know how to configure network interfaces and other core FreeBSD
       subsystems (Chapter 12, Configuration and Tuning).

     * Have a good understanding of FreeBSD networking (Part IV, "Network
       Communication").

   The HAST project was sponsored by The FreeBSD Foundation with support from
   http://www.omc.net/ and http://www.transip.nl/.

  18.14.1. HAST Operation

   HAST provides synchronous block-level replication between two physical
   machines: the primary, also known as the master node, and the secondary,
   or slave node. These two machines together are referred to as a cluster.

   Since HAST works in a primary-secondary configuration, it allows only one
   of the cluster nodes to be active at any given time. The primary node,
   also called active, is the one which will handle all the I/O requests to
   HAST-managed devices. The secondary node is automatically synchronized
   from the primary node.

   The physical components of the HAST system are the local disk on primary
   node, and the disk on the remote, secondary node.

   HAST operates synchronously on a block level, making it transparent to
   file systems and applications. HAST provides regular GEOM providers in
   /dev/hast/ for use by other tools or applications. There is no difference
   between using HAST-provided devices and raw disks or partitions.

   Each write, delete, or flush operation is sent to both the local disk and
   to the remote disk over TCP/IP. Each read operation is served from the
   local disk, unless the local disk is not up-to-date or an I/O error
   occurs. In such cases, the read operation is sent to the secondary node.

   HAST tries to provide fast failure recovery. For this reason, it is
   important to reduce synchronization time after a node's outage. To provide
   fast synchronization, HAST manages an on-disk bitmap of dirty extents and
   only synchronizes those during a regular synchronization, with an
   exception of the initial sync.

   There are many ways to handle synchronization. HAST implements several
   replication modes to handle different synchronization methods:

     * memsync: This mode reports a write operation as completed when the
       local write operation is finished and when the remote node
       acknowledges data arrival, but before actually storing the data. The
       data on the remote node will be stored directly after sending the
       acknowledgement. This mode is intended to reduce latency, but still
       provides good reliability. This mode is the default.

     * fullsync: This mode reports a write operation as completed when both
       the local write and the remote write complete. This is the safest and
       the slowest replication mode.

     * async: This mode reports a write operation as completed when the local
       write completes. This is the fastest and the most dangerous
       replication mode. It should only be used when replicating to a distant
       node where latency is too high for other modes.

  18.14.2. HAST Configuration

   The HAST framework consists of several components:

     * The hastd(8) daemon which provides data synchronization. When this
       daemon is started, it will automatically load geom_gate.ko.

     * The userland management utility, hastctl(8).

     * The hast.conf(5) configuration file. This file must exist before
       starting hastd.

   Users who prefer to statically build GEOM_GATE support into the kernel
   should add this line to the custom kernel configuration file, then rebuild
   the kernel using the instructions in Chapter 8, Configuring the FreeBSD
   Kernel:

 options GEOM_GATE

   The following example describes how to configure two nodes in
   master-slave/primary-secondary operation using HAST to replicate the data
   between the two. The nodes will be called hasta, with an IP address of
   172.16.0.1, and hastb, with an IP address of 172.16.0.2. Both nodes will
   have a dedicated hard drive /dev/ad6 of the same size for HAST operation.
   The HAST pool, sometimes referred to as a resource or the GEOM provider in
   /dev/hast/, will be called test.

   Configuration of HAST is done using /etc/hast.conf. This file should be
   identical on both nodes. The simplest configuration is:

 resource test {
         on hasta {
                 local /dev/ad6
                 remote 172.16.0.2
         }
         on hastb {
                 local /dev/ad6
                 remote 172.16.0.1
         }
 }

   For more advanced configuration, refer to hast.conf(5).

  Tip:

   It is also possible to use host names in the remote statements if the
   hosts are resolvable and defined either in /etc/hosts or in the local DNS.

   Once the configuration exists on both nodes, the HAST pool can be created.
   Run these commands on both nodes to place the initial metadata onto the
   local disk and to start hastd(8):

 # hastctl create test
 # service hastd onestart

  Note:

   It is not possible to use GEOM providers with an existing file system or
   to convert an existing storage to a HAST-managed pool. This procedure
   needs to store some metadata on the provider and there will not be enough
   required space available on an existing provider.

   A HAST node's primary or secondary role is selected by an administrator,
   or software like Heartbeat, using hastctl(8). On the primary node, hasta,
   issue this command:

 # hastctl role primary test

   Run this command on the secondary node, hastb:

 # hastctl role secondary test

   Verify the result by running hastctl on each node:

 # hastctl status test

   Check the status line in the output. If it says degraded, something is
   wrong with the configuration file. It should say complete on each node,
   meaning that the synchronization between the nodes has started. The
   synchronization completes when hastctl status reports 0 bytes of dirty
   extents.

   The next step is to create a file system on the GEOM provider and mount
   it. This must be done on the primary node. Creating the file system can
   take a few minutes, depending on the size of the hard drive. This example
   creates a UFS file system on /dev/hast/test:

 # newfs -U /dev/hast/test
 # mkdir /hast/test
 # mount /dev/hast/test /hast/test

   Once the HAST framework is configured properly, the final step is to make
   sure that HAST is started automatically during system boot. Add this line
   to /etc/rc.conf:

 hastd_enable="YES"

    18.14.2.1. Failover Configuration

   The goal of this example is to build a robust storage system which is
   resistant to the failure of any given node. If the primary node fails, the
   secondary node is there to take over seamlessly, check and mount the file
   system, and continue to work without missing a single bit of data.

   To accomplish this task, the Common Address Redundancy Protocol (CARP) is
   used to provide for automatic failover at the IP layer. CARP allows
   multiple hosts on the same network segment to share an IP address. Set up
   CARP on both nodes of the cluster according to the documentation available
   in Section 32.10, "Common Address Redundancy Protocol (CARP)". In this
   example, each node will have its own management IP address and a shared IP
   address of 172.16.0.254. The primary HAST node of the cluster must be the
   master CARP node.

   The HAST pool created in the previous section is now ready to be exported
   to the other hosts on the network. This can be accomplished by exporting
   it through NFS or Samba, using the shared IP address 172.16.0.254. The
   only problem which remains unresolved is an automatic failover should the
   primary node fail.

   In the event of CARP interfaces going up or down, the FreeBSD operating
   system generates a devd(8) event, making it possible to watch for state
   changes on the CARP interfaces. A state change on the CARP interface is an
   indication that one of the nodes failed or came back online. These state
   change events make it possible to run a script which will automatically
   handle the HAST failover.

   To catch state changes on the CARP interfaces, add this configuration to
   /etc/devd.conf on each node:

 notify 30 {
         match "system" "IFNET";
         match "subsystem" "carp0";
         match "type" "LINK_UP";
         action "/usr/local/sbin/carp-hast-switch master";
 };

 notify 30 {
         match "system" "IFNET";
         match "subsystem" "carp0";
         match "type" "LINK_DOWN";
         action "/usr/local/sbin/carp-hast-switch slave";
 };

  Note:

   If the systems are running FreeBSD 10 or higher, replace carp0 with the
   name of the CARP-configured interface.

   Restart devd(8) on both nodes to put the new configuration into effect:

 # service devd restart

   When the specified interface state changes by going up or down , the
   system generates a notification, allowing the devd(8) subsystem to run the
   specified automatic failover script, /usr/local/sbin/carp-hast-switch. For
   further clarification about this configuration, refer to devd.conf(5).

   Here is an example of an automated failover script:

 #!/bin/sh

 # Original script by Freddie Cash <fjwcash@gmail.com>
 # Modified by Michael W. Lucas <mwlucas@BlackHelicopters.org>
 # and Viktor Petersson <vpetersson@wireload.net>

 # The names of the HAST resources, as listed in /etc/hast.conf
 resources="test"

 # delay in mounting HAST resource after becoming master
 # make your best guess
 delay=3

 # logging
 log="local0.debug"
 name="carp-hast"

 # end of user configurable stuff

 case "$1" in
         master)
                 logger -p $log -t $name "Switching to primary provider for ${resources}."
                 sleep ${delay}

                 # Wait for any "hastd secondary" processes to stop
                 for disk in ${resources}; do
                         while $( pgrep -lf "hastd: ${disk} \(secondary\)" > /dev/null 2>&1 ); do
                                 sleep 1
                         done

                         # Switch role for each disk
                         hastctl role primary ${disk}
                         if [ $? -ne 0 ]; then
                                 logger -p $log -t $name "Unable to change role to primary for resource ${disk}."
                                 exit 1
                         fi
                 done

                 # Wait for the /dev/hast/* devices to appear
                 for disk in ${resources}; do
                         for I in $( jot 60 ); do
                                 [ -c "/dev/hast/${disk}" ] && break
                                 sleep 0.5
                         done

                         if [ ! -c "/dev/hast/${disk}" ]; then
                                 logger -p $log -t $name "GEOM provider /dev/hast/${disk} did not appear."
                                 exit 1
                         fi
                 done

                 logger -p $log -t $name "Role for HAST resources ${resources} switched to primary."


                 logger -p $log -t $name "Mounting disks."
                 for disk in ${resources}; do
                         mkdir -p /hast/${disk}
                         fsck -p -y -t ufs /dev/hast/${disk}
                         mount /dev/hast/${disk} /hast/${disk}
                 done

         ;;

         slave)
                 logger -p $log -t $name "Switching to secondary provider for ${resources}."

                 # Switch roles for the HAST resources
                 for disk in ${resources}; do
                         if ! mount | grep -q "^/dev/hast/${disk} on "
                         then
                         else
                                 umount -f /hast/${disk}
                         fi
                         sleep $delay
                         hastctl role secondary ${disk} 2>&1
                         if [ $? -ne 0 ]; then
                                 logger -p $log -t $name "Unable to switch role to secondary for resource ${disk}."
                                 exit 1
                         fi
                         logger -p $log -t $name "Role switched to secondary for resource ${disk}."
                 done
         ;;
 esac

   In a nutshell, the script takes these actions when a node becomes master:

     * Promotes the HAST pool to primary on the other node.

     * Checks the file system under the HAST pool.

     * Mounts the pool.

   When a node becomes secondary:

     * Unmounts the HAST pool.

     * Degrades the HAST pool to secondary.

  Caution:

   This is just an example script which serves as a proof of concept. It does
   not handle all the possible scenarios and can be extended or altered in
   any way, for example, to start or stop required services.

  Tip:

   For this example, a standard UFS file system was used. To reduce the time
   needed for recovery, a journal-enabled UFS or ZFS file system can be used
   instead.

   More detailed information with additional examples can be found at
   http://wiki.FreeBSD.org/HAST.

  18.14.3. Troubleshooting

   HAST should generally work without issues. However, as with any other
   software product, there may be times when it does not work as supposed.
   The sources of the problems may be different, but the rule of thumb is to
   ensure that the time is synchronized between the nodes of the cluster.

   When troubleshooting HAST, the debugging level of hastd(8) should be
   increased by starting hastd with -d. This argument may be specified
   multiple times to further increase the debugging level. Consider also
   using -F, which starts hastd in the foreground.

    18.14.3.1. Recovering from the Split-brain Condition

   Split-brain occurs when the nodes of the cluster are unable to communicate
   with each other, and both are configured as primary. This is a dangerous
   condition because it allows both nodes to make incompatible changes to the
   data. This problem must be corrected manually by the system administrator.

   The administrator must either decide which node has more important
   changes, or perform the merge manually. Then, let HAST perform full
   synchronization of the node which has the broken data. To do this, issue
   these commands on the node which needs to be resynchronized:

 # hastctl role init test
 # hastctl create test
 # hastctl role secondary test

Chapter 19. GEOM: Modular Disk Transformation Framework

   Written by Tom Rhodes.
   Table of Contents

   19.1. Synopsis

   19.2. RAID0 - Striping

   19.3. RAID1 - Mirroring

   19.4. RAID3 - Byte-level Striping with Dedicated Parity

   19.5. Software RAID Devices

   19.6. GEOM Gate Network

   19.7. Labeling Disk Devices

   19.8. UFS Journaling Through GEOM

19.1. Synopsis

   In FreeBSD, the GEOM framework permits access and control to classes, such
   as Master Boot Records and BSD labels, through the use of providers, or
   the disk devices in /dev. By supporting various software RAID
   configurations, GEOM transparently provides access to the operating system
   and operating system utilities.

   This chapter covers the use of disks under the GEOM framework in FreeBSD.
   This includes the major RAID control utilities which use the framework for
   configuration. This chapter is not a definitive guide to RAID
   configurations and only GEOM-supported RAID classifications are discussed.

   After reading this chapter, you will know:

     * What type of RAID support is available through GEOM.

     * How to use the base utilities to configure, maintain, and manipulate
       the various RAID levels.

     * How to mirror, stripe, encrypt, and remotely connect disk devices
       through GEOM.

     * How to troubleshoot disks attached to the GEOM framework.

   Before reading this chapter, you should:

     * Understand how FreeBSD treats disk devices (Chapter 18, Storage).

     * Know how to configure and install a new kernel (Chapter 8, Configuring
       the FreeBSD Kernel).

19.2. RAID0 - Striping

   Written by Tom Rhodes and Murray Stokely.

   Striping combines several disk drives into a single volume. Striping can
   be performed through the use of hardware RAID controllers. The GEOM disk
   subsystem provides software support for disk striping, also known as
   RAID0, without the need for a RAID disk controller.

   In RAID0, data is split into blocks that are written across all the drives
   in the array. As seen in the following illustration, instead of having to
   wait on the system to write 256k to one disk, RAID0 can simultaneously
   write 64k to each of the four disks in the array, offering superior I/O
   performance. This performance can be enhanced further by using multiple
   disk controllers.

                           Disk Striping Illustration

   Each disk in a RAID0 stripe must be of the same size, since I/O requests
   are interleaved to read or write to multiple disks in parallel.

  Note:

   RAID0 does not provide any redundancy. This means that if one disk in the
   array fails, all of the data on the disks is lost. If the data is
   important, implement a backup strategy that regularly saves backups to a
   remote system or device.

   The process for creating a software, GEOM-based RAID0 on a FreeBSD system
   using commodity disks is as follows. Once the stripe is created, refer to
   gstripe(8) for more information on how to control an existing stripe.

   Procedure 19.1. Creating a Stripe of Unformatted ATA Disks
    1. Load the geom_stripe.ko module:

 # kldload geom_stripe

    2. Ensure that a suitable mount point exists. If this volume will become
       a root partition, then temporarily use another mount point such as
       /mnt.

    3. Determine the device names for the disks which will be striped, and
       create the new stripe device. For example, to stripe two unused and
       unpartitioned ATA disks with device names of /dev/ad2 and /dev/ad3:

 # gstripe label -v st0 /dev/ad2 /dev/ad3
 Metadata value stored on /dev/ad2.
 Metadata value stored on /dev/ad3.
 Done.

    4. Write a standard label, also known as a partition table, on the new
       volume and install the default bootstrap code:

 # bsdlabel -wB /dev/stripe/st0

    5. This process should create two other devices in /dev/stripe in
       addition to st0. Those include st0a and st0c. At this point, a UFS
       file system can be created on st0a using newfs:

 # newfs -U /dev/stripe/st0a

       Many numbers will glide across the screen, and after a few seconds,
       the process will be complete. The volume has been created and is ready
       to be mounted.

    6. To manually mount the created disk stripe:

 # mount /dev/stripe/st0a /mnt

    7. To mount this striped file system automatically during the boot
       process, place the volume information in /etc/fstab. In this example,
       a permanent mount point, named stripe, is created:

 # mkdir /stripe
 # echo "/dev/stripe/st0a /stripe ufs rw 2 2" \
 >> /etc/fstab

    8. The geom_stripe.ko module must also be automatically loaded during
       system initialization, by adding a line to /boot/loader.conf:

 # echo 'geom_stripe_load="YES"' >> /boot/loader.conf

19.3. RAID1 - Mirroring

   RAID1, or mirroring, is the technique of writing the same data to more
   than one disk drive. Mirrors are usually used to guard against data loss
   due to drive failure. Each drive in a mirror contains an identical copy of
   the data. When an individual drive fails, the mirror continues to work,
   providing data from the drives that are still functioning. The computer
   keeps running, and the administrator has time to replace the failed drive
   without user interruption.

   Two common situations are illustrated in these examples. The first creates
   a mirror out of two new drives and uses it as a replacement for an
   existing single drive. The second example creates a mirror on a single new
   drive, copies the old drive's data to it, then inserts the old drive into
   the mirror. While this procedure is slightly more complicated, it only
   requires one new drive.

   Traditionally, the two drives in a mirror are identical in model and
   capacity, but gmirror(8) does not require that. Mirrors created with
   dissimilar drives will have a capacity equal to that of the smallest drive
   in the mirror. Extra space on larger drives will be unused. Drives
   inserted into the mirror later must have at least as much capacity as the
   smallest drive already in the mirror.

  Warning:

   The mirroring procedures shown here are non-destructive, but as with any
   major disk operation, make a full backup first.

  Warning:

   While dump(8) is used in these procedures to copy file systems, it does
   not work on file systems with soft updates journaling. See tunefs(8) for
   information on detecting and disabling soft updates journaling.

  19.3.1. Metadata Issues

   Many disk systems store metadata at the end of each disk. Old metadata
   should be erased before reusing the disk for a mirror. Most problems are
   caused by two particular types of leftover metadata: GPT partition tables
   and old metadata from a previous mirror.

   GPT metadata can be erased with gpart(8). This example erases both primary
   and backup GPT partition tables from disk ada8:

 # gpart destroy -F ada8

   A disk can be removed from an active mirror and the metadata erased in one
   step using gmirror(8). Here, the example disk ada8 is removed from the
   active mirror gm4:

 # gmirror remove gm4 ada8

   If the mirror is not running, but old mirror metadata is still on the
   disk, use gmirror clear to remove it:

 # gmirror clear ada8

   gmirror(8) stores one block of metadata at the end of the disk. As GPT
   partition schemes also store metadata at the end of the disk, mirroring
   entire GPT disks with gmirror(8) is not recommended. MBR partitioning is
   used here because it only stores a partition table at the start of the
   disk and does not conflict with the mirror metadata.

  19.3.2. Creating a Mirror with Two New Disks

   In this example, FreeBSD has already been installed on a single disk,
   ada0. Two new disks, ada1 and ada2, have been connected to the system. A
   new mirror will be created on these two disks and used to replace the old
   single disk.

   The geom_mirror.ko kernel module must either be built into the kernel or
   loaded at boot- or run-time. Manually load the kernel module now:

 # gmirror load

   Create the mirror with the two new drives:

 # gmirror label -v gm0 /dev/ada1 /dev/ada2

   gm0 is a user-chosen device name assigned to the new mirror. After the
   mirror has been started, this device name appears in /dev/mirror/.

   MBR and bsdlabel partition tables can now be created on the mirror with
   gpart(8). This example uses a traditional file system layout, with
   partitions for /, swap, /var, /tmp, and /usr. A single / and a swap
   partition will also work.

   Partitions on the mirror do not have to be the same size as those on the
   existing disk, but they must be large enough to hold all the data already
   present on ada0.

 # gpart create -s MBR mirror/gm0
 # gpart add -t freebsd -a 4k mirror/gm0
 # gpart show mirror/gm0
 =>       63  156301423  mirror/gm0  MBR  (74G)
          63         63                    - free -  (31k)
         126  156301299                 1  freebsd  (74G)
   156301425         61                    - free -  (30k)

 # gpart create -s BSD mirror/gm0s1
 # gpart add -t freebsd-ufs  -a 4k -s 2g mirror/gm0s1
 # gpart add -t freebsd-swap -a 4k -s 4g mirror/gm0s1
 # gpart add -t freebsd-ufs  -a 4k -s 2g mirror/gm0s1
 # gpart add -t freebsd-ufs  -a 4k -s 1g mirror/gm0s1
 # gpart add -t freebsd-ufs  -a 4k       mirror/gm0s1
 # gpart show mirror/gm0s1
 =>        0  156301299  mirror/gm0s1  BSD  (74G)
           0          2                      - free -  (1.0k)
           2    4194304                   1  freebsd-ufs  (2.0G)
     4194306    8388608                   2  freebsd-swap  (4.0G)
    12582914    4194304                   4  freebsd-ufs  (2.0G)
    16777218    2097152                   5  freebsd-ufs  (1.0G)
    18874370  137426928                   6  freebsd-ufs  (65G)
   156301298          1                      - free -  (512B)

   Make the mirror bootable by installing bootcode in the MBR and bsdlabel
   and setting the active slice:

 # gpart bootcode -b /boot/mbr mirror/gm0
 # gpart set -a active -i 1 mirror/gm0
 # gpart bootcode -b /boot/boot mirror/gm0s1

   Format the file systems on the new mirror, enabling soft-updates.

 # newfs -U /dev/mirror/gm0s1a
 # newfs -U /dev/mirror/gm0s1d
 # newfs -U /dev/mirror/gm0s1e
 # newfs -U /dev/mirror/gm0s1f

   File systems from the original ada0 disk can now be copied onto the mirror
   with dump(8) and restore(8).

 # mount /dev/mirror/gm0s1a /mnt
 # dump -C16 -b64 -0aL -f - / | (cd /mnt && restore -rf -)
 # mount /dev/mirror/gm0s1d /mnt/var
 # mount /dev/mirror/gm0s1e /mnt/tmp
 # mount /dev/mirror/gm0s1f /mnt/usr
 # dump -C16 -b64 -0aL -f - /var | (cd /mnt/var && restore -rf -)
 # dump -C16 -b64 -0aL -f - /tmp | (cd /mnt/tmp && restore -rf -)
 # dump -C16 -b64 -0aL -f - /usr | (cd /mnt/usr && restore -rf -)

   Edit /mnt/etc/fstab to point to the new mirror file systems:

 # Device                Mountpoint      FStype  Options Dump    Pass#
 /dev/mirror/gm0s1a      /               ufs     rw      1       1
 /dev/mirror/gm0s1b      none            swap    sw      0       0
 /dev/mirror/gm0s1d      /var            ufs     rw      2       2
 /dev/mirror/gm0s1e      /tmp            ufs     rw      2       2
 /dev/mirror/gm0s1f      /usr            ufs     rw      2       2

   If the geom_mirror.ko kernel module has not been built into the kernel,
   /mnt/boot/loader.conf is edited to load the module at boot:

 geom_mirror_load="YES"

   Reboot the system to test the new mirror and verify that all data has been
   copied. The BIOS will see the mirror as two individual drives rather than
   a mirror. Since the drives are identical, it does not matter which is
   selected to boot.

   See Section 19.3.4, "Troubleshooting" if there are problems booting.
   Powering down and disconnecting the original ada0 disk will allow it to be
   kept as an offline backup.

   In use, the mirror will behave just like the original single drive.

  19.3.3. Creating a Mirror with an Existing Drive

   In this example, FreeBSD has already been installed on a single disk,
   ada0. A new disk, ada1, has been connected to the system. A one-disk
   mirror will be created on the new disk, the existing system copied onto
   it, and then the old disk will be inserted into the mirror. This slightly
   complex procedure is required because gmirror needs to put a 512-byte
   block of metadata at the end of each disk, and the existing ada0 has
   usually had all of its space already allocated.

   Load the geom_mirror.ko kernel module:

 # gmirror load

   Check the media size of the original disk with diskinfo:

 # diskinfo -v ada0 | head -n3
 /dev/ada0
         512             # sectorsize
         1000204821504   # mediasize in bytes (931G)

   Create a mirror on the new disk. To make certain that the mirror capacity
   is not any larger than the original ada0 drive, gnop(8) is used to create
   a fake drive of the exact same size. This drive does not store any data,
   but is used only to limit the size of the mirror. When gmirror(8) creates
   the mirror, it will restrict the capacity to the size of gzero.nop, even
   if the new ada1 drive has more space. Note that the 1000204821504 in the
   second line is equal to ada0's media size as shown by diskinfo above.

 # geom zero load
 # gnop create -s 1000204821504 gzero
 # gmirror label -v gm0 gzero.nop ada1
 # gmirror forget gm0

   Since gzero.nop does not store any data, the mirror does not see it as
   connected. The mirror is told to "forget" unconnected components, removing
   references to gzero.nop. The result is a mirror device containing only a
   single disk, ada1.

   After creating gm0, view the partition table on ada0. This output is from
   a 1 TB drive. If there is some unallocated space at the end of the drive,
   the contents may be copied directly from ada0 to the new mirror.

   However, if the output shows that all of the space on the disk is
   allocated, as in the following listing, there is no space available for
   the 512-byte mirror metadata at the end of the disk.

 # gpart show ada0
 =>        63  1953525105        ada0  MBR  (931G)
           63  1953525105           1  freebsd  [active]  (931G)

   In this case, the partition table must be edited to reduce the capacity by
   one sector on mirror/gm0. The procedure will be explained later.

   In either case, partition tables on the primary disk should be first
   copied using gpart backup and gpart restore.

 # gpart backup ada0 > table.ada0
 # gpart backup ada0s1 > table.ada0s1

   These commands create two files, table.ada0 and table.ada0s1. This example
   is from a 1 TB drive:

 # cat table.ada0
 MBR 4
 1 freebsd         63 1953525105   [active]

 # cat table.ada0s1
 BSD 8
 1  freebsd-ufs          0    4194304
 2 freebsd-swap    4194304   33554432
 4  freebsd-ufs   37748736   50331648
 5  freebsd-ufs   88080384   41943040
 6  freebsd-ufs  130023424  838860800
 7  freebsd-ufs  968884224  984640881

   If no free space is shown at the end of the disk, the size of both the
   slice and the last partition must be reduced by one sector. Edit the two
   files, reducing the size of both the slice and last partition by one.
   These are the last numbers in each listing.

 # cat table.ada0
 MBR 4
 1 freebsd         63 1953525104   [active]

 # cat table.ada0s1
 BSD 8
 1  freebsd-ufs          0    4194304
 2 freebsd-swap    4194304   33554432
 4  freebsd-ufs   37748736   50331648
 5  freebsd-ufs   88080384   41943040
 6  freebsd-ufs  130023424  838860800
 7  freebsd-ufs  968884224  984640880

   If at least one sector was unallocated at the end of the disk, these two
   files can be used without modification.

   Now restore the partition table into mirror/gm0:

 # gpart restore mirror/gm0 < table.ada0
 # gpart restore mirror/gm0s1 < table.ada0s1

   Check the partition table with gpart show. This example has gm0s1a for /,
   gm0s1d for /var, gm0s1e for /usr, gm0s1f for /data1, and gm0s1g for
   /data2.

 # gpart show mirror/gm0
 =>        63  1953525104  mirror/gm0  MBR  (931G)
           63  1953525042           1  freebsd  [active]  (931G)
   1953525105          62              - free -  (31k)

 # gpart show mirror/gm0s1
 =>         0  1953525042  mirror/gm0s1  BSD  (931G)
            0     2097152             1  freebsd-ufs  (1.0G)
      2097152    16777216             2  freebsd-swap  (8.0G)
     18874368    41943040             4  freebsd-ufs  (20G)
     60817408    20971520             5  freebsd-ufs  (10G)
     81788928   629145600             6  freebsd-ufs  (300G)
    710934528  1242590514             7  freebsd-ufs  (592G)
   1953525042          63                - free -  (31k)

   Both the slice and the last partition must have at least one free block at
   the end of the disk.

   Create file systems on these new partitions. The number of partitions will
   vary to match the original disk, ada0.

 # newfs -U /dev/mirror/gm0s1a
 # newfs -U /dev/mirror/gm0s1d
 # newfs -U /dev/mirror/gm0s1e
 # newfs -U /dev/mirror/gm0s1f
 # newfs -U /dev/mirror/gm0s1g

   Make the mirror bootable by installing bootcode in the MBR and bsdlabel
   and setting the active slice:

 # gpart bootcode -b /boot/mbr mirror/gm0
 # gpart set -a active -i 1 mirror/gm0
 # gpart bootcode -b /boot/boot mirror/gm0s1

   Adjust /etc/fstab to use the new partitions on the mirror. Back up this
   file first by copying it to /etc/fstab.orig.

 # cp /etc/fstab /etc/fstab.orig

   Edit /etc/fstab, replacing /dev/ada0 with mirror/gm0.

 # Device                Mountpoint      FStype  Options Dump    Pass#
 /dev/mirror/gm0s1a      /               ufs     rw      1       1
 /dev/mirror/gm0s1b      none            swap    sw      0       0
 /dev/mirror/gm0s1d      /var            ufs     rw      2       2
 /dev/mirror/gm0s1e      /usr            ufs     rw      2       2
 /dev/mirror/gm0s1f      /data1          ufs     rw      2       2
 /dev/mirror/gm0s1g      /data2          ufs     rw      2       2

   If the geom_mirror.ko kernel module has not been built into the kernel,
   edit /boot/loader.conf to load it at boot:

 geom_mirror_load="YES"

   File systems from the original disk can now be copied onto the mirror with
   dump(8) and restore(8). Each file system dumped with dump -L will create a
   snapshot first, which can take some time.

 # mount /dev/mirror/gm0s1a /mnt
 # dump -C16 -b64 -0aL -f - /    | (cd /mnt && restore -rf -)
 # mount /dev/mirror/gm0s1d /mnt/var
 # mount /dev/mirror/gm0s1e /mnt/usr
 # mount /dev/mirror/gm0s1f /mnt/data1
 # mount /dev/mirror/gm0s1g /mnt/data2
 # dump -C16 -b64 -0aL -f - /usr | (cd /mnt/usr && restore -rf -)
 # dump -C16 -b64 -0aL -f - /var | (cd /mnt/var && restore -rf -)
 # dump -C16 -b64 -0aL -f - /data1 | (cd /mnt/data1 && restore -rf -)
 # dump -C16 -b64 -0aL -f - /data2 | (cd /mnt/data2 && restore -rf -)

   Restart the system, booting from ada1. If everything is working, the
   system will boot from mirror/gm0, which now contains the same data as ada0
   had previously. See Section 19.3.4, "Troubleshooting" if there are
   problems booting.

   At this point, the mirror still consists of only the single ada1 disk.

   After booting from mirror/gm0 successfully, the final step is inserting
   ada0 into the mirror.

  Important:

   When ada0 is inserted into the mirror, its former contents will be
   overwritten by data from the mirror. Make certain that mirror/gm0 has the
   same contents as ada0 before adding ada0 to the mirror. If the contents
   previously copied by dump(8) and restore(8) are not identical to what was
   on ada0, revert /etc/fstab to mount the file systems on ada0, reboot, and
   start the whole procedure again.

 # gmirror insert gm0 ada0
 GEOM_MIRROR: Device gm0: rebuilding provider ada0

   Synchronization between the two disks will start immediately. Use gmirror
   status to view the progress.

 # gmirror status
       Name    Status  Components
 mirror/gm0  DEGRADED  ada1 (ACTIVE)
                       ada0 (SYNCHRONIZING, 64%)

   After a while, synchronization will finish.

 GEOM_MIRROR: Device gm0: rebuilding provider ada0 finished.
 # gmirror status
       Name    Status  Components
 mirror/gm0  COMPLETE  ada1 (ACTIVE)
                       ada0 (ACTIVE)

   mirror/gm0 now consists of the two disks ada0 and ada1, and the contents
   are automatically synchronized with each other. In use, mirror/gm0 will
   behave just like the original single drive.

  19.3.4. Troubleshooting

   If the system no longer boots, BIOS settings may have to be changed to
   boot from one of the new mirrored drives. Either mirror drive can be used
   for booting, as they contain identical data.

   If the boot stops with this message, something is wrong with the mirror
   device:

 Mounting from ufs:/dev/mirror/gm0s1a failed with error 19.

 Loader variables:
   vfs.root.mountfrom=ufs:/dev/mirror/gm0s1a
   vfs.root.mountfrom.options=rw

 Manual root filesystem specification:
   <fstype>:<device> [options]
       Mount <device> using filesystem <fstype>
       and with the specified (optional) option list.

     eg. ufs:/dev/da0s1a
         zfs:tank
         cd9660:/dev/acd0 ro
           (which is equivalent to: mount -t cd9660 -o ro /dev/acd0 /)

   ?               List valid disk boot devices
   .               Yield 1 second (for background tasks)
   <empty line>    Abort manual input

 mountroot>

   Forgetting to load the geom_mirror.ko module in /boot/loader.conf can
   cause this problem. To fix it, boot from a FreeBSD installation media and
   choose Shell at the first prompt. Then load the mirror module and mount
   the mirror device:

 # gmirror load
 # mount /dev/mirror/gm0s1a /mnt

   Edit /mnt/boot/loader.conf, adding a line to load the mirror module:

 geom_mirror_load="YES"

   Save the file and reboot.

   Other problems that cause error 19 require more effort to fix. Although
   the system should boot from ada0, another prompt to select a shell will
   appear if /etc/fstab is incorrect. Enter ufs:/dev/ada0s1a at the boot
   loader prompt and press Enter. Undo the edits in /etc/fstab then mount the
   file systems from the original disk (ada0) instead of the mirror. Reboot
   the system and try the procedure again.

 Enter full pathname of shell or RETURN for /bin/sh:
 # cp /etc/fstab.orig /etc/fstab
 # reboot

  19.3.5. Recovering from Disk Failure

   The benefit of disk mirroring is that an individual disk can fail without
   causing the mirror to lose any data. In the above example, if ada0 fails,
   the mirror will continue to work, providing data from the remaining
   working drive, ada1.

   To replace the failed drive, shut down the system and physically replace
   the failed drive with a new drive of equal or greater capacity.
   Manufacturers use somewhat arbitrary values when rating drives in
   gigabytes, and the only way to really be sure is to compare the total
   count of sectors shown by diskinfo -v. A drive with larger capacity than
   the mirror will work, although the extra space on the new drive will not
   be used.

   After the computer is powered back up, the mirror will be running in a
   "degraded" mode with only one drive. The mirror is told to forget drives
   that are not currently connected:

 # gmirror forget gm0

   Any old metadata should be cleared from the replacement disk using the
   instructions in Section 19.3.1, "Metadata Issues". Then the replacement
   disk, ada4 for this example, is inserted into the mirror:

 # gmirror insert gm0 /dev/ada4

   Resynchronization begins when the new drive is inserted into the mirror.
   This process of copying mirror data to a new drive can take a while.
   Performance of the mirror will be greatly reduced during the copy, so
   inserting new drives is best done when there is low demand on the
   computer.

   Progress can be monitored with gmirror status, which shows drives that are
   being synchronized and the percentage of completion. During
   resynchronization, the status will be DEGRADED, changing to COMPLETE when
   the process is finished.

19.4. RAID3 - Byte-level Striping with Dedicated Parity

   Written by Mark Gladman and Daniel Gerzo.
   Based on documentation by Tom Rhodes and Murray Stokely.

   RAID3 is a method used to combine several disk drives into a single volume
   with a dedicated parity disk. In a RAID3 system, data is split up into a
   number of bytes that are written across all the drives in the array except
   for one disk which acts as a dedicated parity disk. This means that disk
   reads from a RAID3 implementation access all disks in the array.
   Performance can be enhanced by using multiple disk controllers. The RAID3
   array provides a fault tolerance of 1 drive, while providing a capacity of
   1 - 1/n times the total capacity of all drives in the array, where n is
   the number of hard drives in the array. Such a configuration is mostly
   suitable for storing data of larger sizes such as multimedia files.

   At least 3 physical hard drives are required to build a RAID3 array. Each
   disk must be of the same size, since I/O requests are interleaved to read
   or write to multiple disks in parallel. Also, due to the nature of RAID3,
   the number of drives must be equal to 3, 5, 9, 17, and so on, or 2^n + 1.

   This section demonstrates how to create a software RAID3 on a FreeBSD
   system.

  Note:

   While it is theoretically possible to boot from a RAID3 array on FreeBSD,
   that configuration is uncommon and is not advised.

  19.4.1. Creating a Dedicated RAID3 Array

   In FreeBSD, support for RAID3 is implemented by the graid3(8) GEOM class.
   Creating a dedicated RAID3 array on FreeBSD requires the following steps.

    1. First, load the geom_raid3.ko kernel module by issuing one of the
       following commands:

 # graid3 load

       or:

 # kldload geom_raid3

    2. Ensure that a suitable mount point exists. This command creates a new
       directory to use as the mount point:

 # mkdir /multimedia

    3. Determine the device names for the disks which will be added to the
       array, and create the new RAID3 device. The final device listed will
       act as the dedicated parity disk. This example uses three
       unpartitioned ATA drives: ada1 and ada2 for data, and ada3 for parity.

 # graid3 label -v gr0 /dev/ada1 /dev/ada2 /dev/ada3
 Metadata value stored on /dev/ada1.
 Metadata value stored on /dev/ada2.
 Metadata value stored on /dev/ada3.
 Done.

    4. Partition the newly created gr0 device and put a UFS file system on
       it:

 # gpart create -s GPT /dev/raid3/gr0
 # gpart add -t freebsd-ufs /dev/raid3/gr0
 # newfs -j /dev/raid3/gr0p1

       Many numbers will glide across the screen, and after a bit of time,
       the process will be complete. The volume has been created and is ready
       to be mounted:

 # mount /dev/raid3/gr0p1 /multimedia/

       The RAID3 array is now ready to use.

   Additional configuration is needed to retain this setup across system
   reboots.

    1. The geom_raid3.ko module must be loaded before the array can be
       mounted. To automatically load the kernel module during system
       initialization, add the following line to /boot/loader.conf:

 geom_raid3_load="YES"

    2. The following volume information must be added to /etc/fstab in order
       to automatically mount the array's file system during the system boot
       process:

 /dev/raid3/gr0p1        /multimedia     ufs     rw      2       2

19.5. Software RAID Devices

   Originally contributed by Warren Block.

   Some motherboards and expansion cards add some simple hardware, usually
   just a ROM, that allows the computer to boot from a RAID array. After
   booting, access to the RAID array is handled by software running on the
   computer's main processor. This "hardware-assisted software RAID" gives
   RAID arrays that are not dependent on any particular operating system, and
   which are functional even before an operating system is loaded.

   Several levels of RAID are supported, depending on the hardware in use.
   See graid(8) for a complete list.

   graid(8) requires the geom_raid.ko kernel module, which is included in the
   GENERIC kernel starting with FreeBSD 9.1. If needed, it can be loaded
   manually with graid load.

  19.5.1. Creating an Array

   Software RAID devices often have a menu that can be entered by pressing
   special keys when the computer is booting. The menu can be used to create
   and delete RAID arrays. graid(8) can also create arrays directly from the
   command line.

   graid label is used to create a new array. The motherboard used for this
   example has an Intel software RAID chipset, so the Intel metadata format
   is specified. The new array is given a label of gm0, it is a mirror
   (RAID1), and uses drives ada0 and ada1.

  Caution:

   Some space on the drives will be overwritten when they are made into a new
   array. Back up existing data first!

 # graid label Intel gm0 RAID1 ada0 ada1
 GEOM_RAID: Intel-a29ea104: Array Intel-a29ea104 created.
 GEOM_RAID: Intel-a29ea104: Disk ada0 state changed from NONE to ACTIVE.
 GEOM_RAID: Intel-a29ea104: Subdisk gm0:0-ada0 state changed from NONE to ACTIVE.
 GEOM_RAID: Intel-a29ea104: Disk ada1 state changed from NONE to ACTIVE.
 GEOM_RAID: Intel-a29ea104: Subdisk gm0:1-ada1 state changed from NONE to ACTIVE.
 GEOM_RAID: Intel-a29ea104: Array started.
 GEOM_RAID: Intel-a29ea104: Volume gm0 state changed from STARTING to OPTIMAL.
 Intel-a29ea104 created
 GEOM_RAID: Intel-a29ea104: Provider raid/r0 for volume gm0 created.

   A status check shows the new mirror is ready for use:

 # graid status
    Name   Status  Components
 raid/r0  OPTIMAL  ada0 (ACTIVE (ACTIVE))
                   ada1 (ACTIVE (ACTIVE))

   The array device appears in /dev/raid/. The first array is called r0.
   Additional arrays, if present, will be r1, r2, and so on.

   The BIOS menu on some of these devices can create arrays with special
   characters in their names. To avoid problems with those special
   characters, arrays are given simple numbered names like r0. To show the
   actual labels, like gm0 in the example above, use sysctl(8):

 # sysctl kern.geom.raid.name_format=1

  19.5.2. Multiple Volumes

   Some software RAID devices support more than one volume on an array.
   Volumes work like partitions, allowing space on the physical drives to be
   split and used in different ways. For example, Intel software RAID devices
   support two volumes. This example creates a 40 G mirror for safely storing
   the operating system, followed by a 20 G RAID0 (stripe) volume for fast
   temporary storage:

 # graid label -S 40G Intel gm0 RAID1 ada0 ada1
 # graid add -S 20G gm0 RAID0

   Volumes appear as additional rX entries in /dev/raid/. An array with two
   volumes will show r0 and r1.

   See graid(8) for the number of volumes supported by different software
   RAID devices.

  19.5.3. Converting a Single Drive to a Mirror

   Under certain specific conditions, it is possible to convert an existing
   single drive to a graid(8) array without reformatting. To avoid data loss
   during the conversion, the existing drive must meet these minimum
   requirements:

     * The drive must be partitioned with the MBR partitioning scheme. GPT or
       other partitioning schemes with metadata at the end of the drive will
       be overwritten and corrupted by the graid(8) metadata.

     * There must be enough unpartitioned and unused space at the end of the
       drive to hold the graid(8) metadata. This metadata varies in size, but
       the largest occupies 64 M, so at least that much free space is
       recommended.

   If the drive meets these requirements, start by making a full backup. Then
   create a single-drive mirror with that drive:

 # graid label Intel gm0 RAID1 ada0 NONE

   graid(8) metadata was written to the end of the drive in the unused space.
   A second drive can now be inserted into the mirror:

 # graid insert raid/r0 ada1

   Data from the original drive will immediately begin to be copied to the
   second drive. The mirror will operate in degraded status until the copy is
   complete.

  19.5.4. Inserting New Drives into the Array

   Drives can be inserted into an array as replacements for drives that have
   failed or are missing. If there are no failed or missing drives, the new
   drive becomes a spare. For example, inserting a new drive into a working
   two-drive mirror results in a two-drive mirror with one spare drive, not a
   three-drive mirror.

   In the example mirror array, data immediately begins to be copied to the
   newly-inserted drive. Any existing information on the new drive will be
   overwritten.

 # graid insert raid/r0 ada1
 GEOM_RAID: Intel-a29ea104: Disk ada1 state changed from NONE to ACTIVE.
 GEOM_RAID: Intel-a29ea104: Subdisk gm0:1-ada1 state changed from NONE to NEW.
 GEOM_RAID: Intel-a29ea104: Subdisk gm0:1-ada1 state changed from NEW to REBUILD.
 GEOM_RAID: Intel-a29ea104: Subdisk gm0:1-ada1 rebuild start at 0.

  19.5.5. Removing Drives from the Array

   Individual drives can be permanently removed from a from an array and
   their metadata erased:

 # graid remove raid/r0 ada1
 GEOM_RAID: Intel-a29ea104: Disk ada1 state changed from ACTIVE to OFFLINE.
 GEOM_RAID: Intel-a29ea104: Subdisk gm0:1-[unknown] state changed from ACTIVE to NONE.
 GEOM_RAID: Intel-a29ea104: Volume gm0 state changed from OPTIMAL to DEGRADED.

  19.5.6. Stopping the Array

   An array can be stopped without removing metadata from the drives. The
   array will be restarted when the system is booted.

 # graid stop raid/r0

  19.5.7. Checking Array Status

   Array status can be checked at any time. After a drive was added to the
   mirror in the example above, data is being copied from the original drive
   to the new drive:

 # graid status
    Name    Status  Components
 raid/r0  DEGRADED  ada0 (ACTIVE (ACTIVE))
                    ada1 (ACTIVE (REBUILD 28%))

   Some types of arrays, like RAID0 or CONCAT, may not be shown in the status
   report if disks have failed. To see these partially-failed arrays, add
   -ga:

 # graid status -ga
           Name  Status  Components
 Intel-e2d07d9a  BROKEN  ada6 (ACTIVE (ACTIVE))

  19.5.8. Deleting Arrays

   Arrays are destroyed by deleting all of the volumes from them. When the
   last volume present is deleted, the array is stopped and metadata is
   removed from the drives:

 # graid delete raid/r0

  19.5.9. Deleting Unexpected Arrays

   Drives may unexpectedly contain graid(8) metadata, either from previous
   use or manufacturer testing. graid(8) will detect these drives and create
   an array, interfering with access to the individual drive. To remove the
   unwanted metadata:

    1. Boot the system. At the boot menu, select 2 for the loader prompt.
       Enter:

 OK set kern.geom.raid.enable=0
 OK boot

       The system will boot with graid(8) disabled.

    2. Back up all data on the affected drive.

    3. As a workaround, graid(8) array detection can be disabled by adding

 kern.geom.raid.enable=0

       to /boot/loader.conf.

       To permanently remove the graid(8) metadata from the affected drive,
       boot a FreeBSD installation CD-ROM or memory stick, and select Shell.
       Use status to find the name of the array, typically raid/r0:

 # graid status
    Name   Status  Components
 raid/r0  OPTIMAL  ada0 (ACTIVE (ACTIVE))
                   ada1 (ACTIVE (ACTIVE))

       Delete the volume by name:

 # graid delete raid/r0

       If there is more than one volume shown, repeat the process for each
       volume. After the last array has been deleted, the volume will be
       destroyed.

       Reboot and verify data, restoring from backup if necessary. After the
       metadata has been removed, the kern.geom.raid.enable=0 entry in
       /boot/loader.conf can also be removed.

19.6. GEOM Gate Network

   GEOM provides a simple mechanism for providing remote access to devices
   such as disks, CDs, and file systems through the use of the GEOM Gate
   network daemon, ggated. The system with the device runs the server daemon
   which handles requests made by clients using ggatec. The devices should
   not contain any sensitive data as the connection between the client and
   the server is not encrypted.

   Similar to NFS, which is discussed in Section 30.3, "Network File System
   (NFS)", ggated is configured using an exports file. This file specifies
   which systems are permitted to access the exported resources and what
   level of access they are offered. For example, to give the client
   192.168.1.5 read and write access to the fourth slice on the first SCSI
   disk, create /etc/gg.exports with this line:

 192.168.1.5 RW /dev/da0s4d

   Before exporting the device, ensure it is not currently mounted. Then,
   start ggated:

 # ggated

   Several options are available for specifying an alternate listening port
   or changing the default location of the exports file. Refer to ggated(8)
   for details.

   To access the exported device on the client machine, first use ggatec to
   specify the IP address of the server and the device name of the exported
   device. If successful, this command will display a ggate device name to
   mount. Mount that specified device name on a free mount point. This
   example connects to the /dev/da0s4d partition on 192.168.1.1, then mounts
   /dev/ggate0 on /mnt:

 # ggatec create -o rw 192.168.1.1 /dev/da0s4d
 ggate0
 # mount /dev/ggate0 /mnt

   The device on the server may now be accessed through /mnt on the client.
   For more details about ggatec and a few usage examples, refer to
   ggatec(8).

  Note:

   The mount will fail if the device is currently mounted on either the
   server or any other client on the network. If simultaneous access is
   needed to network resources, use NFS instead.

   When the device is no longer needed, unmount it with umount so that the
   resource is available to other clients.

19.7. Labeling Disk Devices

   During system initialization, the FreeBSD kernel creates device nodes as
   devices are found. This method of probing for devices raises some issues.
   For instance, what if a new disk device is added via USB? It is likely
   that a flash device may be handed the device name of da0 and the original
   da0 shifted to da1. This will cause issues mounting file systems if they
   are listed in /etc/fstab which may also prevent the system from booting.

   One solution is to chain SCSI devices in order so a new device added to
   the SCSI card will be issued unused device numbers. But what about USB
   devices which may replace the primary SCSI disk? This happens because USB
   devices are usually probed before the SCSI card. One solution is to only
   insert these devices after the system has been booted. Another method is
   to use only a single ATA drive and never list the SCSI devices in
   /etc/fstab.

   A better solution is to use glabel to label the disk devices and use the
   labels in /etc/fstab. Since glabel stores the label in the last sector of
   a given provider, the label will remain persistent across reboots. By
   using this label as a device, the file-system may always be mounted
   regardless of what device node it is accessed through.

  Note:

   glabel can create both transient and permanent labels. Only permanent
   labels are consistent across reboots. Refer to glabel(8) for more
   information on the differences between labels.

  19.7.1. Label Types and Examples

   Permanent labels can be a generic or a file system label. Permanent file
   system labels can be created with tunefs(8) or newfs(8). These types of
   labels are created in a sub-directory of /dev, and will be named according
   to the file system type. For example, UFS2 file system labels will be
   created in /dev/ufs. Generic permanent labels can be created with glabel
   label. These are not file system specific and will be created in
   /dev/label.

   Temporary labels are destroyed at the next reboot. These labels are
   created in /dev/label and are suited to experimentation. A temporary label
   can be created using glabel create.

   To create a permanent label for a UFS2 file system without destroying any
   data, issue the following command:

 # tunefs -L home /dev/da3

   A label should now exist in /dev/ufs which may be added to /etc/fstab:

 /dev/ufs/home           /home            ufs     rw              2      2

  Note:

   The file system must not be mounted while attempting to run tunefs.

   Now the file system may be mounted:

 # mount /home

   From this point on, so long as the geom_label.ko kernel module is loaded
   at boot with /boot/loader.conf or the GEOM_LABEL kernel option is present,
   the device node may change without any ill effect on the system.

   File systems may also be created with a default label by using the -L flag
   with newfs. Refer to newfs(8) for more information.

   The following command can be used to destroy the label:

 # glabel destroy home

   The following example shows how to label the partitions of a boot disk.

   Example 19.1. Labeling Partitions on the Boot Disk

   By permanently labeling the partitions on the boot disk, the system should
   be able to continue to boot normally, even if the disk is moved to another
   controller or transferred to a different system. For this example, it is
   assumed that a single ATA disk is used, which is currently recognized by
   the system as ad0. It is also assumed that the standard FreeBSD partition
   scheme is used, with /, /var, /usr and /tmp, as well as a swap partition.

   Reboot the system, and at the loader(8) prompt, press 4 to boot into
   single user mode. Then enter the following commands:

 # glabel label rootfs /dev/ad0s1a
 GEOM_LABEL: Label for provider /dev/ad0s1a is label/rootfs
 # glabel label var /dev/ad0s1d
 GEOM_LABEL: Label for provider /dev/ad0s1d is label/var
 # glabel label usr /dev/ad0s1f
 GEOM_LABEL: Label for provider /dev/ad0s1f is label/usr
 # glabel label tmp /dev/ad0s1e
 GEOM_LABEL: Label for provider /dev/ad0s1e is label/tmp
 # glabel label swap /dev/ad0s1b
 GEOM_LABEL: Label for provider /dev/ad0s1b is label/swap
 # exit

   The system will continue with multi-user boot. After the boot completes,
   edit /etc/fstab and replace the conventional device names, with their
   respective labels. The final /etc/fstab will look like this:

 # Device                Mountpoint      FStype  Options         Dump    Pass#
 /dev/label/swap         none            swap    sw              0       0
 /dev/label/rootfs       /               ufs     rw              1       1
 /dev/label/tmp          /tmp            ufs     rw              2       2
 /dev/label/usr          /usr            ufs     rw              2       2
 /dev/label/var          /var            ufs     rw              2       2

   The system can now be rebooted. If everything went well, it will come up
   normally and mount will show:

 # mount
 /dev/label/rootfs on / (ufs, local)
 devfs on /dev (devfs, local)
 /dev/label/tmp on /tmp (ufs, local, soft-updates)
 /dev/label/usr on /usr (ufs, local, soft-updates)
 /dev/label/var on /var (ufs, local, soft-updates)

   The glabel(8) class supports a label type for UFS file systems, based on
   the unique file system id, ufsid. These labels may be found in /dev/ufsid
   and are created automatically during system startup. It is possible to use
   ufsid labels to mount partitions using /etc/fstab. Use glabel status to
   receive a list of file systems and their corresponding ufsid labels:

 % glabel status
                   Name  Status  Components
 ufsid/486b6fc38d330916     N/A  ad4s1d
 ufsid/486b6fc16926168e     N/A  ad4s1f

   In the above example, ad4s1d represents /var, while ad4s1f represents
   /usr. Using the ufsid values shown, these partitions may now be mounted
   with the following entries in /etc/fstab:

 /dev/ufsid/486b6fc38d330916        /var        ufs        rw        2      2
 /dev/ufsid/486b6fc16926168e        /usr        ufs        rw        2      2

   Any partitions with ufsid labels can be mounted in this way, eliminating
   the need to manually create permanent labels, while still enjoying the
   benefits of device name independent mounting.

19.8. UFS Journaling Through GEOM

   Support for journals on UFS file systems is available on FreeBSD. The
   implementation is provided through the GEOM subsystem and is configured
   using gjournal. Unlike other file system journaling implementations, the
   gjournal method is block based and not implemented as part of the file
   system. It is a GEOM extension.

   Journaling stores a log of file system transactions, such as changes that
   make up a complete disk write operation, before meta-data and file writes
   are committed to the disk. This transaction log can later be replayed to
   redo file system transactions, preventing file system inconsistencies.

   This method provides another mechanism to protect against data loss and
   inconsistencies of the file system. Unlike Soft Updates, which tracks and
   enforces meta-data updates, and snapshots, which create an image of the
   file system, a log is stored in disk space specifically for this task. For
   better performance, the journal may be stored on another disk. In this
   configuration, the journal provider or storage device should be listed
   after the device to enable journaling on.

   The GENERIC kernel provides support for gjournal. To automatically load
   the geom_journal.ko kernel module at boot time, add the following line to
   /boot/loader.conf:

 geom_journal_load="YES"

   If a custom kernel is used, ensure the following line is in the kernel
   configuration file:

 options GEOM_JOURNAL

   Once the module is loaded, a journal can be created on a new file system
   using the following steps. In this example, da4 is a new SCSI disk:

 # gjournal load
 # gjournal label /dev/da4

   This will load the module and create a /dev/da4.journal device node on
   /dev/da4.

   A UFS file system may now be created on the journaled device, then mounted
   on an existing mount point:

 # newfs -O 2 -J /dev/da4.journal
 # mount /dev/da4.journal /mnt

  Note:

   In the case of several slices, a journal will be created for each
   individual slice. For instance, if ad4s1 and ad4s2 are both slices, then
   gjournal will create ad4s1.journal and ad4s2.journal.

   Journaling may also be enabled on current file systems by using tunefs.
   However, always make a backup before attempting to alter an existing file
   system. In most cases, gjournal will fail if it is unable to create the
   journal, but this does not protect against data loss incurred as a result
   of misusing tunefs. Refer to gjournal(8) and tunefs(8) for more
   information about these commands.

   It is possible to journal the boot disk of a FreeBSD system. Refer to the
   article Implementing UFS Journaling on a Desktop PC for detailed
   instructions.

Chapter 20. The Z File System (ZFS)

   Written by Tom Rhodes, Allan Jude, Benedict Reuschling and Warren Block.
   Table of Contents

   20.1. What Makes ZFS Different

   20.2. Quick Start Guide

   20.3. zpool Administration

   20.4. zfs Administration

   20.5. Delegated Administration

   20.6. Advanced Topics

   20.7. Additional Resources

   20.8. ZFS Features and Terminology

   The Z File System, or ZFS, is an advanced file system designed to overcome
   many of the major problems found in previous designs.

   Originally developed at Sun(TM), ongoing open source ZFS development has
   moved to the OpenZFS Project.

   ZFS has three major design goals:

     * Data integrity: All data includes a checksum of the data. When data is
       written, the checksum is calculated and written along with it. When
       that data is later read back, the checksum is calculated again. If the
       checksums do not match, a data error has been detected. ZFS will
       attempt to automatically correct errors when data redundancy is
       available.

     * Pooled storage: physical storage devices are added to a pool, and
       storage space is allocated from that shared pool. Space is available
       to all file systems, and can be increased by adding new storage
       devices to the pool.

     * Performance: multiple caching mechanisms provide increased
       performance. ARC is an advanced memory-based read cache. A second
       level of disk-based read cache can be added with L2ARC, and disk-based
       synchronous write cache is available with ZIL.

   A complete list of features and terminology is shown in Section 20.8, "ZFS
   Features and Terminology".

20.1. What Makes ZFS Different

   ZFS is significantly different from any previous file system because it is
   more than just a file system. Combining the traditionally separate roles
   of volume manager and file system provides ZFS with unique advantages. The
   file system is now aware of the underlying structure of the disks.
   Traditional file systems could only be created on a single disk at a time.
   If there were two disks then two separate file systems would have to be
   created. In a traditional hardware RAID configuration, this problem was
   avoided by presenting the operating system with a single logical disk made
   up of the space provided by a number of physical disks, on top of which
   the operating system placed a file system. Even in the case of software
   RAID solutions like those provided by GEOM, the UFS file system living on
   top of the RAID transform believed that it was dealing with a single
   device. ZFS's combination of the volume manager and the file system solves
   this and allows the creation of many file systems all sharing a pool of
   available storage. One of the biggest advantages to ZFS's awareness of the
   physical layout of the disks is that existing file systems can be grown
   automatically when additional disks are added to the pool. This new space
   is then made available to all of the file systems. ZFS also has a number
   of different properties that can be applied to each file system, giving
   many advantages to creating a number of different file systems and
   datasets rather than a single monolithic file system.

20.2. Quick Start Guide

   There is a startup mechanism that allows FreeBSD to mount ZFS pools during
   system initialization. To enable it, add this line to /etc/rc.conf:

 zfs_enable="YES"

   Then start the service:

 # service zfs start

   The examples in this section assume three SCSI disks with the device names
   da0, da1, and da2. Users of SATA hardware should instead use ada device
   names.

  20.2.1. Single Disk Pool

   To create a simple, non-redundant pool using a single disk device:

 # zpool create example /dev/da0

   To view the new pool, review the output of df:

 # df
 Filesystem  1K-blocks    Used    Avail Capacity  Mounted on
 /dev/ad0s1a   2026030  235230  1628718    13%    /
 devfs               1       1        0   100%    /dev
 /dev/ad0s1d  54098308 1032846 48737598     2%    /usr
 example      17547136       0 17547136     0%    /example

   This output shows that the example pool has been created and mounted. It
   is now accessible as a file system. Files can be created on it and users
   can browse it:

 # cd /example
 # ls
 # touch testfile
 # ls -al
 total 4
 drwxr-xr-x   2 root  wheel    3 Aug 29 23:15 .
 drwxr-xr-x  21 root  wheel  512 Aug 29 23:12 ..
 -rw-r--r--   1 root  wheel    0 Aug 29 23:15 testfile

   However, this pool is not taking advantage of any ZFS features. To create
   a dataset on this pool with compression enabled:

 # zfs create example/compressed
 # zfs set compression=gzip example/compressed

   The example/compressed dataset is now a ZFS compressed file system. Try
   copying some large files to /example/compressed.

   Compression can be disabled with:

 # zfs set compression=off example/compressed

   To unmount a file system, use zfs umount and then verify with df:

 # zfs umount example/compressed
 # df
 Filesystem  1K-blocks    Used    Avail Capacity  Mounted on
 /dev/ad0s1a   2026030  235232  1628716    13%    /
 devfs               1       1        0   100%    /dev
 /dev/ad0s1d  54098308 1032864 48737580     2%    /usr
 example      17547008       0 17547008     0%    /example

   To re-mount the file system to make it accessible again, use zfs mount and
   verify with df:

 # zfs mount example/compressed
 # df
 Filesystem         1K-blocks    Used    Avail Capacity  Mounted on
 /dev/ad0s1a          2026030  235234  1628714    13%    /
 devfs                      1       1        0   100%    /dev
 /dev/ad0s1d         54098308 1032864 48737580     2%    /usr
 example             17547008       0 17547008     0%    /example
 example/compressed  17547008       0 17547008     0%    /example/compressed

   The pool and file system may also be observed by viewing the output from
   mount:

 # mount
 /dev/ad0s1a on / (ufs, local)
 devfs on /dev (devfs, local)
 /dev/ad0s1d on /usr (ufs, local, soft-updates)
 example on /example (zfs, local)
 example/compressed on /example/compressed (zfs, local)

   After creation, ZFS datasets can be used like any file systems. However,
   many other features are available which can be set on a per-dataset basis.
   In the example below, a new file system called data is created. Important
   files will be stored here, so it is configured to keep two copies of each
   data block:

 # zfs create example/data
 # zfs set copies=2 example/data

   It is now possible to see the data and space utilization by issuing df:

 # df
 Filesystem         1K-blocks    Used    Avail Capacity  Mounted on
 /dev/ad0s1a          2026030  235234  1628714    13%    /
 devfs                      1       1        0   100%    /dev
 /dev/ad0s1d         54098308 1032864 48737580     2%    /usr
 example             17547008       0 17547008     0%    /example
 example/compressed  17547008       0 17547008     0%    /example/compressed
 example/data        17547008       0 17547008     0%    /example/data

   Notice that each file system on the pool has the same amount of available
   space. This is the reason for using df in these examples, to show that the
   file systems use only the amount of space they need and all draw from the
   same pool. ZFS eliminates concepts such as volumes and partitions, and
   allows multiple file systems to occupy the same pool.

   To destroy the file systems and then destroy the pool as it is no longer
   needed:

 # zfs destroy example/compressed
 # zfs destroy example/data
 # zpool destroy example

  20.2.2. RAID-Z

   Disks fail. One method of avoiding data loss from disk failure is to
   implement RAID. ZFS supports this feature in its pool design. RAID-Z pools
   require three or more disks but provide more usable space than mirrored
   pools.

   This example creates a RAID-Z pool, specifying the disks to add to the
   pool:

 # zpool create storage raidz da0 da1 da2

  Note:

   Sun(TM) recommends that the number of devices used in a RAID-Z
   configuration be between three and nine. For environments requiring a
   single pool consisting of 10 disks or more, consider breaking it up into
   smaller RAID-Z groups. If only two disks are available and redundancy is a
   requirement, consider using a ZFS mirror. Refer to zpool(8) for more
   details.

   The previous example created the storage zpool. This example makes a new
   file system called home in that pool:

 # zfs create storage/home

   Compression and keeping extra copies of directories and files can be
   enabled:

 # zfs set copies=2 storage/home
 # zfs set compression=gzip storage/home

   To make this the new home directory for users, copy the user data to this
   directory and create the appropriate symbolic links:

 # cp -rp /home/* /storage/home
 # rm -rf /home /usr/home
 # ln -s /storage/home /home
 # ln -s /storage/home /usr/home

   Users data is now stored on the freshly-created /storage/home. Test by
   adding a new user and logging in as that user.

   Try creating a file system snapshot which can be rolled back later:

 # zfs snapshot storage/home@08-30-08

   Snapshots can only be made of a full file system, not a single directory
   or file.

   The @ character is a delimiter between the file system name or the volume
   name. If an important directory has been accidentally deleted, the file
   system can be backed up, then rolled back to an earlier snapshot when the
   directory still existed:

 # zfs rollback storage/home@08-30-08

   To list all available snapshots, run ls in the file system's .zfs/snapshot
   directory. For example, to see the previously taken snapshot:

 # ls /storage/home/.zfs/snapshot

   It is possible to write a script to perform regular snapshots on user
   data. However, over time, snapshots can consume a great deal of disk
   space. The previous snapshot can be removed using the command:

 # zfs destroy storage/home@08-30-08

   After testing, /storage/home can be made the real /home using this
   command:

 # zfs set mountpoint=/home storage/home

   Run df and mount to confirm that the system now treats the file system as
   the real /home:

 # mount
 /dev/ad0s1a on / (ufs, local)
 devfs on /dev (devfs, local)
 /dev/ad0s1d on /usr (ufs, local, soft-updates)
 storage on /storage (zfs, local)
 storage/home on /home (zfs, local)
 # df
 Filesystem   1K-blocks    Used    Avail Capacity  Mounted on
 /dev/ad0s1a    2026030  235240  1628708    13%    /
 devfs                1       1        0   100%    /dev
 /dev/ad0s1d   54098308 1032826 48737618     2%    /usr
 storage       26320512       0 26320512     0%    /storage
 storage/home  26320512       0 26320512     0%    /home

   This completes the RAID-Z configuration. Daily status updates about the
   file systems created can be generated as part of the nightly periodic(8)
   runs. Add this line to /etc/periodic.conf:

 daily_status_zfs_enable="YES"

  20.2.3. Recovering RAID-Z

   Every software RAID has a method of monitoring its state. The status of
   RAID-Z devices may be viewed with this command:

 # zpool status -x

   If all pools are Online and everything is normal, the message shows:

 all pools are healthy

   If there is an issue, perhaps a disk is in the Offline state, the pool
   state will look similar to:

   pool: storage
  state: DEGRADED
 status: One or more devices has been taken offline by the administrator.
         Sufficient replicas exist for the pool to continue functioning in a
         degraded state.
 action: Online the device using 'zpool online' or replace the device with
         'zpool replace'.
  scrub: none requested
 config:

         NAME        STATE     READ WRITE CKSUM
         storage     DEGRADED     0     0     0
           raidz1    DEGRADED     0     0     0
             da0     ONLINE       0     0     0
             da1     OFFLINE      0     0     0
             da2     ONLINE       0     0     0

 errors: No known data errors

   This indicates that the device was previously taken offline by the
   administrator with this command:

 # zpool offline storage da1

   Now the system can be powered down to replace da1. When the system is back
   online, the failed disk can replaced in the pool:

 # zpool replace storage da1

   From here, the status may be checked again, this time without -x so that
   all pools are shown:

 # zpool status storage
  pool: storage
  state: ONLINE
  scrub: resilver completed with 0 errors on Sat Aug 30 19:44:11 2008
 config:

         NAME        STATE     READ WRITE CKSUM
         storage     ONLINE       0     0     0
           raidz1    ONLINE       0     0     0
             da0     ONLINE       0     0     0
             da1     ONLINE       0     0     0
             da2     ONLINE       0     0     0

 errors: No known data errors

   In this example, everything is normal.

  20.2.4. Data Verification

   ZFS uses checksums to verify the integrity of stored data. These are
   enabled automatically upon creation of file systems.

  Warning:

   Checksums can be disabled, but it is not recommended! Checksums take very
   little storage space and provide data integrity. Many ZFS features will
   not work properly with checksums disabled. There is no noticeable
   performance gain from disabling these checksums.

   Checksum verification is known as scrubbing. Verify the data integrity of
   the storage pool with this command:

 # zpool scrub storage

   The duration of a scrub depends on the amount of data stored. Larger
   amounts of data will take proportionally longer to verify. Scrubs are very
   I/O intensive, and only one scrub is allowed to run at a time. After the
   scrub completes, the status can be viewed with status:

 # zpool status storage
  pool: storage
  state: ONLINE
  scrub: scrub completed with 0 errors on Sat Jan 26 19:57:37 2013
 config:

         NAME        STATE     READ WRITE CKSUM
         storage     ONLINE       0     0     0
           raidz1    ONLINE       0     0     0
             da0     ONLINE       0     0     0
             da1     ONLINE       0     0     0
             da2     ONLINE       0     0     0

 errors: No known data errors

   The completion date of the last scrub operation is displayed to help track
   when another scrub is required. Routine scrubs help protect data from
   silent corruption and ensure the integrity of the pool.

   Refer to zfs(8) and zpool(8) for other ZFS options.

20.3. zpool Administration

   ZFS administration is divided between two main utilities. The zpool
   utility controls the operation of the pool and deals with adding,
   removing, replacing, and managing disks. The zfs utility deals with
   creating, destroying, and managing datasets, both file systems and
   volumes.

  20.3.1. Creating and Destroying Storage Pools

   Creating a ZFS storage pool (zpool) involves making a number of decisions
   that are relatively permanent because the structure of the pool cannot be
   changed after the pool has been created. The most important decision is
   what types of vdevs into which to group the physical disks. See the list
   of vdev types for details about the possible options. After the pool has
   been created, most vdev types do not allow additional disks to be added to
   the vdev. The exceptions are mirrors, which allow additional disks to be
   added to the vdev, and stripes, which can be upgraded to mirrors by
   attaching an additional disk to the vdev. Although additional vdevs can be
   added to expand a pool, the layout of the pool cannot be changed after
   pool creation. Instead, the data must be backed up and the pool destroyed
   and recreated.

   Create a simple mirror pool:

 # zpool create mypool mirror /dev/ada1 /dev/ada2
 # zpool status
   pool: mypool
  state: ONLINE
   scan: none requested
 config:

         NAME        STATE     READ WRITE CKSUM
         mypool      ONLINE       0     0     0
           mirror-0  ONLINE       0     0     0
             ada1    ONLINE       0     0     0
             ada2    ONLINE       0     0     0

 errors: No known data errors

   Multiple vdevs can be created at once. Specify multiple groups of disks
   separated by the vdev type keyword, mirror in this example:

 # zpool create mypool mirror /dev/ada1 /dev/ada2 mirror /dev/ada3 /dev/ada4
 # zpool status
   pool: mypool
  state: ONLINE
   scan: none requested
 config:

         NAME        STATE     READ WRITE CKSUM
         mypool      ONLINE       0     0     0
           mirror-0  ONLINE       0     0     0
             ada1    ONLINE       0     0     0
             ada2    ONLINE       0     0     0
           mirror-1  ONLINE       0     0     0
             ada3    ONLINE       0     0     0
             ada4    ONLINE       0     0     0

 errors: No known data errors

   Pools can also be constructed using partitions rather than whole disks.
   Putting ZFS in a separate partition allows the same disk to have other
   partitions for other purposes. In particular, partitions with bootcode and
   file systems needed for booting can be added. This allows booting from
   disks that are also members of a pool. There is no performance penalty on
   FreeBSD when using a partition rather than a whole disk. Using partitions
   also allows the administrator to under-provision the disks, using less
   than the full capacity. If a future replacement disk of the same nominal
   size as the original actually has a slightly smaller capacity, the smaller
   partition will still fit, and the replacement disk can still be used.

   Create a RAID-Z2 pool using partitions:

 # zpool create mypool raidz2 /dev/ada0p3 /dev/ada1p3 /dev/ada2p3 /dev/ada3p3 /dev/ada4p3 /dev/ada5p3
 # zpool status
   pool: mypool
  state: ONLINE
   scan: none requested
 config:

         NAME        STATE     READ WRITE CKSUM
         mypool      ONLINE       0     0     0
           raidz2-0  ONLINE       0     0     0
             ada0p3  ONLINE       0     0     0
             ada1p3  ONLINE       0     0     0
             ada2p3  ONLINE       0     0     0
             ada3p3  ONLINE       0     0     0
             ada4p3  ONLINE       0     0     0
             ada5p3  ONLINE       0     0     0

 errors: No known data errors

   A pool that is no longer needed can be destroyed so that the disks can be
   reused. Destroying a pool involves first unmounting all of the datasets in
   that pool. If the datasets are in use, the unmount operation will fail and
   the pool will not be destroyed. The destruction of the pool can be forced
   with -f, but this can cause undefined behavior in applications which had
   open files on those datasets.

  20.3.2. Adding and Removing Devices

   There are two cases for adding disks to a zpool: attaching a disk to an
   existing vdev with zpool attach, or adding vdevs to the pool with zpool
   add. Only some vdev types allow disks to be added to the vdev after
   creation.

   A pool created with a single disk lacks redundancy. Corruption can be
   detected but not repaired, because there is no other copy of the data. The
   copies property may be able to recover from a small failure such as a bad
   sector, but does not provide the same level of protection as mirroring or
   RAID-Z. Starting with a pool consisting of a single disk vdev, zpool
   attach can be used to add an additional disk to the vdev, creating a
   mirror. zpool attach can also be used to add additional disks to a mirror
   group, increasing redundancy and read performance. If the disks being used
   for the pool are partitioned, replicate the layout of the first disk on to
   the second, gpart backup and gpart restore can be used to make this
   process easier.

   Upgrade the single disk (stripe) vdev ada0p3 to a mirror by attaching
   ada1p3:

 # zpool status
   pool: mypool
  state: ONLINE
   scan: none requested
 config:

         NAME        STATE     READ WRITE CKSUM
         mypool      ONLINE       0     0     0
           ada0p3    ONLINE       0     0     0

 errors: No known data errors
 # zpool attach mypool ada0p3 ada1p3
 Make sure to wait until resilver is done before rebooting.

 If you boot from pool 'mypool', you may need to update
 boot code on newly attached disk 'ada1p3'.

 Assuming you use GPT partitioning and 'da0' is your new boot disk
 you may use the following command:

         gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1 da0
 # gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1 ada1
 bootcode written to ada1
 # zpool status
   pool: mypool
  state: ONLINE
 status: One or more devices is currently being resilvered.  The pool will
         continue to function, possibly in a degraded state.
 action: Wait for the resilver to complete.
   scan: resilver in progress since Fri May 30 08:19:19 2014
         527M scanned out of 781M at 47.9M/s, 0h0m to go
         527M resilvered, 67.53% done
 config:

         NAME        STATE     READ WRITE CKSUM
         mypool      ONLINE       0     0     0
           mirror-0  ONLINE       0     0     0
             ada0p3  ONLINE       0     0     0
             ada1p3  ONLINE       0     0     0  (resilvering)

 errors: No known data errors
 # zpool status
   pool: mypool
  state: ONLINE
   scan: resilvered 781M in 0h0m with 0 errors on Fri May 30 08:15:58 2014
 config:

         NAME        STATE     READ WRITE CKSUM
         mypool      ONLINE       0     0     0
           mirror-0  ONLINE       0     0     0
             ada0p3  ONLINE       0     0     0
             ada1p3  ONLINE       0     0     0

 errors: No known data errors

   When adding disks to the existing vdev is not an option, as for RAID-Z, an
   alternative method is to add another vdev to the pool. Additional vdevs
   provide higher performance, distributing writes across the vdevs. Each
   vdev is responsible for providing its own redundancy. It is possible, but
   discouraged, to mix vdev types, like mirror and RAID-Z. Adding a
   non-redundant vdev to a pool containing mirror or RAID-Z vdevs risks the
   data on the entire pool. Writes are distributed, so the failure of the
   non-redundant disk will result in the loss of a fraction of every block
   that has been written to the pool.

   Data is striped across each of the vdevs. For example, with two mirror
   vdevs, this is effectively a RAID 10 that stripes writes across two sets
   of mirrors. Space is allocated so that each vdev reaches 100% full at the
   same time. There is a performance penalty if the vdevs have different
   amounts of free space, as a disproportionate amount of the data is written
   to the less full vdev.

   When attaching additional devices to a boot pool, remember to update the
   bootcode.

   Attach a second mirror group (ada2p3 and ada3p3) to the existing mirror:

 # zpool status
   pool: mypool
  state: ONLINE
   scan: resilvered 781M in 0h0m with 0 errors on Fri May 30 08:19:35 2014
 config:

         NAME        STATE     READ WRITE CKSUM
         mypool      ONLINE       0     0     0
           mirror-0  ONLINE       0     0     0
             ada0p3  ONLINE       0     0     0
             ada1p3  ONLINE       0     0     0

 errors: No known data errors
 # zpool add mypool mirror ada2p3 ada3p3
 # gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1 ada2
 bootcode written to ada2
 # gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1 ada3
 bootcode written to ada3
 # zpool status
   pool: mypool
  state: ONLINE
   scan: scrub repaired 0 in 0h0m with 0 errors on Fri May 30 08:29:51 2014
 config:

         NAME        STATE     READ WRITE CKSUM
         mypool      ONLINE       0     0     0
           mirror-0  ONLINE       0     0     0
             ada0p3  ONLINE       0     0     0
             ada1p3  ONLINE       0     0     0
           mirror-1  ONLINE       0     0     0
             ada2p3  ONLINE       0     0     0
             ada3p3  ONLINE       0     0     0

 errors: No known data errors

   Currently, vdevs cannot be removed from a pool, and disks can only be
   removed from a mirror if there is enough remaining redundancy. If only one
   disk in a mirror group remains, it ceases to be a mirror and reverts to
   being a stripe, risking the entire pool if that remaining disk fails.

   Remove a disk from a three-way mirror group:

 # zpool status
   pool: mypool
  state: ONLINE
   scan: scrub repaired 0 in 0h0m with 0 errors on Fri May 30 08:29:51 2014
 config:

         NAME        STATE     READ WRITE CKSUM
         mypool      ONLINE       0     0     0
           mirror-0  ONLINE       0     0     0
             ada0p3  ONLINE       0     0     0
             ada1p3  ONLINE       0     0     0
             ada2p3  ONLINE       0     0     0

 errors: No known data errors
 # zpool detach mypool ada2p3
 # zpool status
   pool: mypool
  state: ONLINE
   scan: scrub repaired 0 in 0h0m with 0 errors on Fri May 30 08:29:51 2014
 config:

         NAME        STATE     READ WRITE CKSUM
         mypool      ONLINE       0     0     0
           mirror-0  ONLINE       0     0     0
             ada0p3  ONLINE       0     0     0
             ada1p3  ONLINE       0     0     0

 errors: No known data errors

  20.3.3. Checking the Status of a Pool

   Pool status is important. If a drive goes offline or a read, write, or
   checksum error is detected, the corresponding error count increases. The
   status output shows the configuration and status of each device in the
   pool and the status of the entire pool. Actions that need to be taken and
   details about the last scrub are also shown.

 # zpool status
   pool: mypool
  state: ONLINE
   scan: scrub repaired 0 in 2h25m with 0 errors on Sat Sep 14 04:25:50 2013
 config:

         NAME        STATE     READ WRITE CKSUM
         mypool      ONLINE       0     0     0
           raidz2-0  ONLINE       0     0     0
             ada0p3  ONLINE       0     0     0
             ada1p3  ONLINE       0     0     0
             ada2p3  ONLINE       0     0     0
             ada3p3  ONLINE       0     0     0
             ada4p3  ONLINE       0     0     0
             ada5p3  ONLINE       0     0     0

 errors: No known data errors

  20.3.4. Clearing Errors

   When an error is detected, the read, write, or checksum counts are
   incremented. The error message can be cleared and the counts reset with
   zpool clear mypool. Clearing the error state can be important for
   automated scripts that alert the administrator when the pool encounters an
   error. Further errors may not be reported if the old errors are not
   cleared.

  20.3.5. Replacing a Functioning Device

   There are a number of situations where it may be desirable to replace one
   disk with a different disk. When replacing a working disk, the process
   keeps the old disk online during the replacement. The pool never enters a
   degraded state, reducing the risk of data loss. zpool replace copies all
   of the data from the old disk to the new one. After the operation
   completes, the old disk is disconnected from the vdev. If the new disk is
   larger than the old disk, it may be possible to grow the zpool, using the
   new space. See Growing a Pool.

   Replace a functioning device in the pool:

 # zpool status
   pool: mypool
  state: ONLINE
   scan: none requested
 config:

         NAME        STATE     READ WRITE CKSUM
         mypool      ONLINE       0     0     0
           mirror-0  ONLINE       0     0     0
             ada0p3  ONLINE       0     0     0
             ada1p3  ONLINE       0     0     0

 errors: No known data errors
 # zpool replace mypool ada1p3 ada2p3
 Make sure to wait until resilver is done before rebooting.

 If you boot from pool 'zroot', you may need to update
 boot code on newly attached disk 'ada2p3'.

 Assuming you use GPT partitioning and 'da0' is your new boot disk
 you may use the following command:

         gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1 da0
 # gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1 ada2
 # zpool status
   pool: mypool
  state: ONLINE
 status: One or more devices is currently being resilvered.  The pool will
         continue to function, possibly in a degraded state.
 action: Wait for the resilver to complete.
   scan: resilver in progress since Mon Jun  2 14:21:35 2014
         604M scanned out of 781M at 46.5M/s, 0h0m to go
         604M resilvered, 77.39% done
 config:

         NAME             STATE     READ WRITE CKSUM
         mypool           ONLINE       0     0     0
           mirror-0       ONLINE       0     0     0
             ada0p3       ONLINE       0     0     0
             replacing-1  ONLINE       0     0     0
               ada1p3     ONLINE       0     0     0
               ada2p3     ONLINE       0     0     0  (resilvering)

 errors: No known data errors
 # zpool status
   pool: mypool
  state: ONLINE
   scan: resilvered 781M in 0h0m with 0 errors on Mon Jun  2 14:21:52 2014
 config:

         NAME        STATE     READ WRITE CKSUM
         mypool      ONLINE       0     0     0
           mirror-0  ONLINE       0     0     0
             ada0p3  ONLINE       0     0     0
             ada2p3  ONLINE       0     0     0

 errors: No known data errors

  20.3.6. Dealing with Failed Devices

   When a disk in a pool fails, the vdev to which the disk belongs enters the
   degraded state. All of the data is still available, but performance may be
   reduced because missing data must be calculated from the available
   redundancy. To restore the vdev to a fully functional state, the failed
   physical device must be replaced. ZFS is then instructed to begin the
   resilver operation. Data that was on the failed device is recalculated
   from available redundancy and written to the replacement device. After
   completion, the vdev returns to online status.

   If the vdev does not have any redundancy, or if multiple devices have
   failed and there is not enough redundancy to compensate, the pool enters
   the faulted state. If a sufficient number of devices cannot be reconnected
   to the pool, the pool becomes inoperative and data must be restored from
   backups.

   When replacing a failed disk, the name of the failed disk is replaced with
   the GUID of the device. A new device name parameter for zpool replace is
   not required if the replacement device has the same device name.

   Replace a failed disk using zpool replace:

 # zpool status
   pool: mypool
  state: DEGRADED
 status: One or more devices could not be opened.  Sufficient replicas exist for
         the pool to continue functioning in a degraded state.
 action: Attach the missing device and online it using 'zpool online'.
    see: http://illumos.org/msg/ZFS-8000-2Q
   scan: none requested
 config:

         NAME                    STATE     READ WRITE CKSUM
         mypool                  DEGRADED     0     0     0
           mirror-0              DEGRADED     0     0     0
             ada0p3              ONLINE       0     0     0
             316502962686821739  UNAVAIL      0     0     0  was /dev/ada1p3

 errors: No known data errors
 # zpool replace mypool 316502962686821739 ada2p3
 # zpool status
   pool: mypool
  state: DEGRADED
 status: One or more devices is currently being resilvered.  The pool will
         continue to function, possibly in a degraded state.
 action: Wait for the resilver to complete.
   scan: resilver in progress since Mon Jun  2 14:52:21 2014
         641M scanned out of 781M at 49.3M/s, 0h0m to go
         640M resilvered, 82.04% done
 config:

         NAME                        STATE     READ WRITE CKSUM
         mypool                      DEGRADED     0     0     0
           mirror-0                  DEGRADED     0     0     0
             ada0p3                  ONLINE       0     0     0
             replacing-1             UNAVAIL      0     0     0
               15732067398082357289  UNAVAIL      0     0     0  was /dev/ada1p3/old
               ada2p3                ONLINE       0     0     0  (resilvering)

 errors: No known data errors
 # zpool status
   pool: mypool
  state: ONLINE
   scan: resilvered 781M in 0h0m with 0 errors on Mon Jun  2 14:52:38 2014
 config:

         NAME        STATE     READ WRITE CKSUM
         mypool      ONLINE       0     0     0
           mirror-0  ONLINE       0     0     0
             ada0p3  ONLINE       0     0     0
             ada2p3  ONLINE       0     0     0

 errors: No known data errors

  20.3.7. Scrubbing a Pool

   It is recommended that pools be scrubbed regularly, ideally at least once
   every month. The scrub operation is very disk-intensive and will reduce
   performance while running. Avoid high-demand periods when scheduling scrub
   or use vfs.zfs.scrub_delay to adjust the relative priority of the scrub to
   prevent it interfering with other workloads.

 # zpool scrub mypool
 # zpool status
   pool: mypool
  state: ONLINE
   scan: scrub in progress since Wed Feb 19 20:52:54 2014
         116G scanned out of 8.60T at 649M/s, 3h48m to go
         0 repaired, 1.32% done
 config:

         NAME        STATE     READ WRITE CKSUM
         mypool      ONLINE       0     0     0
           raidz2-0  ONLINE       0     0     0
             ada0p3  ONLINE       0     0     0
             ada1p3  ONLINE       0     0     0
             ada2p3  ONLINE       0     0     0
             ada3p3  ONLINE       0     0     0
             ada4p3  ONLINE       0     0     0
             ada5p3  ONLINE       0     0     0

 errors: No known data errors

   In the event that a scrub operation needs to be cancelled, issue zpool
   scrub -s mypool.

  20.3.8. Self-Healing

   The checksums stored with data blocks enable the file system to self-heal.
   This feature will automatically repair data whose checksum does not match
   the one recorded on another device that is part of the storage pool. For
   example, a mirror with two disks where one drive is starting to
   malfunction and cannot properly store the data any more. This is even
   worse when the data has not been accessed for a long time, as with long
   term archive storage. Traditional file systems need to run algorithms that
   check and repair the data like fsck(8). These commands take time, and in
   severe cases, an administrator has to manually decide which repair
   operation must be performed. When ZFS detects a data block with a checksum
   that does not match, it tries to read the data from the mirror disk. If
   that disk can provide the correct data, it will not only give that data to
   the application requesting it, but also correct the wrong data on the disk
   that had the bad checksum. This happens without any interaction from a
   system administrator during normal pool operation.

   The next example demonstrates this self-healing behavior. A mirrored pool
   of disks /dev/ada0 and /dev/ada1 is created.

 # zpool create healer mirror /dev/ada0 /dev/ada1
 # zpool status healer
   pool: healer
  state: ONLINE
   scan: none requested
 config:

     NAME        STATE     READ WRITE CKSUM
     healer      ONLINE       0     0     0
       mirror-0  ONLINE       0     0     0
        ada0     ONLINE       0     0     0
        ada1     ONLINE       0     0     0

 errors: No known data errors
 # zpool list
 NAME     SIZE  ALLOC   FREE   CKPOINT  EXPANDSZ   FRAG   CAP  DEDUP  HEALTH  ALTROOT
 healer   960M  92.5K   960M         -         -     0%    0%  1.00x  ONLINE  -

   Some important data that to be protected from data errors using the
   self-healing feature is copied to the pool. A checksum of the pool is
   created for later comparison.

 # cp /some/important/data /healer
 # zfs list
 NAME     SIZE  ALLOC   FREE    CAP  DEDUP  HEALTH  ALTROOT
 healer   960M  67.7M   892M     7%  1.00x  ONLINE  -
 # sha1 /healer > checksum.txt
 # cat checksum.txt
 SHA1 (/healer) = 2753eff56d77d9a536ece6694bf0a82740344d1f

   Data corruption is simulated by writing random data to the beginning of
   one of the disks in the mirror. To prevent ZFS from healing the data as
   soon as it is detected, the pool is exported before the corruption and
   imported again afterwards.

  Warning:

   This is a dangerous operation that can destroy vital data. It is shown
   here for demonstrational purposes only and should not be attempted during
   normal operation of a storage pool. Nor should this intentional corruption
   example be run on any disk with a different file system on it. Do not use
   any other disk device names other than the ones that are part of the pool.
   Make certain that proper backups of the pool are created before running
   the command!

 # zpool export healer
 # dd if=/dev/random of=/dev/ada1 bs=1m count=200
 200+0 records in
 200+0 records out
 209715200 bytes transferred in 62.992162 secs (3329227 bytes/sec)
 # zpool import healer

   The pool status shows that one device has experienced an error. Note that
   applications reading data from the pool did not receive any incorrect
   data. ZFS provided data from the ada0 device with the correct checksums.
   The device with the wrong checksum can be found easily as the CKSUM column
   contains a nonzero value.

 # zpool status healer
     pool: healer
    state: ONLINE
   status: One or more devices has experienced an unrecoverable error.  An
           attempt was made to correct the error.  Applications are unaffected.
   action: Determine if the device needs to be replaced, and clear the errors
           using 'zpool clear' or replace the device with 'zpool replace'.
      see: http://illumos.org/msg/ZFS-8000-4J
     scan: none requested
   config:

       NAME        STATE     READ WRITE CKSUM
       healer      ONLINE       0     0     0
         mirror-0  ONLINE       0     0     0
          ada0     ONLINE       0     0     0
          ada1     ONLINE       0     0     1

 errors: No known data errors

   The error was detected and handled by using the redundancy present in the
   unaffected ada0 mirror disk. A checksum comparison with the original one
   will reveal whether the pool is consistent again.

 # sha1 /healer >> checksum.txt
 # cat checksum.txt
 SHA1 (/healer) = 2753eff56d77d9a536ece6694bf0a82740344d1f
 SHA1 (/healer) = 2753eff56d77d9a536ece6694bf0a82740344d1f

   The two checksums that were generated before and after the intentional
   tampering with the pool data still match. This shows how ZFS is capable of
   detecting and correcting any errors automatically when the checksums
   differ. Note that this is only possible when there is enough redundancy
   present in the pool. A pool consisting of a single device has no
   self-healing capabilities. That is also the reason why checksums are so
   important in ZFS and should not be disabled for any reason. No fsck(8) or
   similar file system consistency check program is required to detect and
   correct this and the pool was still available during the time there was a
   problem. A scrub operation is now required to overwrite the corrupted data
   on ada1.

 # zpool scrub healer
 # zpool status healer
   pool: healer
  state: ONLINE
 status: One or more devices has experienced an unrecoverable error.  An
             attempt was made to correct the error.  Applications are unaffected.
 action: Determine if the device needs to be replaced, and clear the errors
             using 'zpool clear' or replace the device with 'zpool replace'.
    see: http://illumos.org/msg/ZFS-8000-4J
   scan: scrub in progress since Mon Dec 10 12:23:30 2012
         10.4M scanned out of 67.0M at 267K/s, 0h3m to go
         9.63M repaired, 15.56% done
 config:

     NAME        STATE     READ WRITE CKSUM
     healer      ONLINE       0     0     0
       mirror-0  ONLINE       0     0     0
        ada0     ONLINE       0     0     0
        ada1     ONLINE       0     0   627  (repairing)

 errors: No known data errors

   The scrub operation reads data from ada0 and rewrites any data with an
   incorrect checksum on ada1. This is indicated by the (repairing) output
   from zpool status. After the operation is complete, the pool status
   changes to:

 # zpool status healer
   pool: healer
  state: ONLINE
 status: One or more devices has experienced an unrecoverable error.  An
         attempt was made to correct the error.  Applications are unaffected.
 action: Determine if the device needs to be replaced, and clear the errors
              using 'zpool clear' or replace the device with 'zpool replace'.
    see: http://illumos.org/msg/ZFS-8000-4J
   scan: scrub repaired 66.5M in 0h2m with 0 errors on Mon Dec 10 12:26:25 2012
 config:

     NAME        STATE     READ WRITE CKSUM
     healer      ONLINE       0     0     0
       mirror-0  ONLINE       0     0     0
        ada0     ONLINE       0     0     0
        ada1     ONLINE       0     0 2.72K

 errors: No known data errors

   After the scrub operation completes and all the data has been synchronized
   from ada0 to ada1, the error messages can be cleared from the pool status
   by running zpool clear.

 # zpool clear healer
 # zpool status healer
   pool: healer
  state: ONLINE
   scan: scrub repaired 66.5M in 0h2m with 0 errors on Mon Dec 10 12:26:25 2012
 config:

     NAME        STATE     READ WRITE CKSUM
     healer      ONLINE       0     0     0
       mirror-0  ONLINE       0     0     0
        ada0     ONLINE       0     0     0
        ada1     ONLINE       0     0     0

 errors: No known data errors

   The pool is now back to a fully working state and all the errors have been
   cleared.

  20.3.9. Growing a Pool

   The usable size of a redundant pool is limited by the capacity of the
   smallest device in each vdev. The smallest device can be replaced with a
   larger device. After completing a replace or resilver operation, the pool
   can grow to use the capacity of the new device. For example, consider a
   mirror of a 1 TB drive and a 2 TB drive. The usable space is 1 TB. When
   the 1 TB drive is replaced with another 2 TB drive, the resilvering
   process copies the existing data onto the new drive. As both of the
   devices now have 2 TB capacity, the mirror's available space can be grown
   to 2 TB.

   Expansion is triggered by using zpool online -e on each device. After
   expansion of all devices, the additional space becomes available to the
   pool.

  20.3.10. Importing and Exporting Pools

   Pools are exported before moving them to another system. All datasets are
   unmounted, and each device is marked as exported but still locked so it
   cannot be used by other disk subsystems. This allows pools to be imported
   on other machines, other operating systems that support ZFS, and even
   different hardware architectures (with some caveats, see zpool(8)). When a
   dataset has open files, zpool export -f can be used to force the export of
   a pool. Use this with caution. The datasets are forcibly unmounted,
   potentially resulting in unexpected behavior by the applications which had
   open files on those datasets.

   Export a pool that is not in use:

 # zpool export mypool

   Importing a pool automatically mounts the datasets. This may not be the
   desired behavior, and can be prevented with zpool import -N. zpool import
   -o sets temporary properties for this import only. zpool import altroot=
   allows importing a pool with a base mount point instead of the root of the
   file system. If the pool was last used on a different system and was not
   properly exported, an import might have to be forced with zpool import -f.
   zpool import -a imports all pools that do not appear to be in use by
   another system.

   List all available pools for import:

 # zpool import
    pool: mypool
      id: 9930174748043525076
   state: ONLINE
  action: The pool can be imported using its name or numeric identifier.
  config:

         mypool      ONLINE
           ada2p3    ONLINE

   Import the pool with an alternative root directory:

 # zpool import -o altroot=/mnt mypool
 # zfs list
 zfs list
 NAME                 USED  AVAIL  REFER  MOUNTPOINT
 mypool               110K  47.0G    31K  /mnt/mypool

  20.3.11. Upgrading a Storage Pool

   After upgrading FreeBSD, or if a pool has been imported from a system
   using an older version of ZFS, the pool can be manually upgraded to the
   latest version of ZFS to support newer features. Consider whether the pool
   may ever need to be imported on an older system before upgrading.
   Upgrading is a one-way process. Older pools can be upgraded, but pools
   with newer features cannot be downgraded.

   Upgrade a v28 pool to support Feature Flags:

 # zpool status
   pool: mypool
  state: ONLINE
 status: The pool is formatted using a legacy on-disk format.  The pool can
         still be used, but some features are unavailable.
 action: Upgrade the pool using 'zpool upgrade'.  Once this is done, the
         pool will no longer be accessible on software that does not support feat
         flags.
   scan: none requested
 config:

         NAME        STATE     READ WRITE CKSUM
         mypool      ONLINE       0     0     0
           mirror-0  ONLINE       0     0     0
             ada0    ONLINE       0     0     0
             ada1    ONLINE       0     0     0

 errors: No known data errors
 # zpool upgrade
 This system supports ZFS pool feature flags.

 The following pools are formatted with legacy version numbers and can
 be upgraded to use feature flags.  After being upgraded, these pools
 will no longer be accessible by software that does not support feature
 flags.

 VER  POOL
 ---  ------------
 28   mypool

 Use 'zpool upgrade -v' for a list of available legacy versions.
 Every feature flags pool has all supported features enabled.
 # zpool upgrade mypool
 This system supports ZFS pool feature flags.

 Successfully upgraded 'mypool' from version 28 to feature flags.
 Enabled the following features on 'mypool':
   async_destroy
   empty_bpobj
   lz4_compress
   multi_vdev_crash_dump

   The newer features of ZFS will not be available until zpool upgrade has
   completed. zpool upgrade -v can be used to see what new features will be
   provided by upgrading, as well as which features are already supported.

   Upgrade a pool to support additional feature flags:

 # zpool status
   pool: mypool
  state: ONLINE
 status: Some supported features are not enabled on the pool. The pool can
         still be used, but some features are unavailable.
 action: Enable all features using 'zpool upgrade'. Once this is done,
         the pool may no longer be accessible by software that does not support
         the features. See zpool-features(7) for details.
   scan: none requested
 config:

         NAME        STATE     READ WRITE CKSUM
         mypool      ONLINE       0     0     0
           mirror-0  ONLINE       0     0     0
             ada0    ONLINE       0     0     0
             ada1    ONLINE       0     0     0

 errors: No known data errors
 # zpool upgrade
 This system supports ZFS pool feature flags.

 All pools are formatted using feature flags.


 Some supported features are not enabled on the following pools. Once a
 feature is enabled the pool may become incompatible with software
 that does not support the feature. See zpool-features(7) for details.

 POOL  FEATURE
 ---------------
 zstore
       multi_vdev_crash_dump
       spacemap_histogram
       enabled_txg
       hole_birth
       extensible_dataset
       bookmarks
       filesystem_limits
 # zpool upgrade mypool
 This system supports ZFS pool feature flags.

 Enabled the following features on 'mypool':
   spacemap_histogram
   enabled_txg
   hole_birth
   extensible_dataset
   bookmarks
   filesystem_limits

  Warning:

   The boot code on systems that boot from a pool must be updated to support
   the new pool version. Use gpart bootcode on the partition that contains
   the boot code. There are two types of bootcode available, depending on way
   the system boots: GPT (the most common option) and EFI (for more modern
   systems).

   For legacy boot using GPT, use the following command:

 # gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1 ada1

   For systems using EFI to boot, execute the following command:

 # gpart bootcode -p /boot/boot1.efifat -i 1 ada1

   Apply the bootcode to all bootable disks in the pool. See gpart(8) for
   more information.

  20.3.12. Displaying Recorded Pool History

   Commands that modify the pool are recorded. Recorded actions include the
   creation of datasets, changing properties, or replacement of a disk. This
   history is useful for reviewing how a pool was created and which user
   performed a specific action and when. History is not kept in a log file,
   but is part of the pool itself. The command to review this history is
   aptly named zpool history:

 # zpool history
 History for 'tank':
 2013-02-26.23:02:35 zpool create tank mirror /dev/ada0 /dev/ada1
 2013-02-27.18:50:58 zfs set atime=off tank
 2013-02-27.18:51:09 zfs set checksum=fletcher4 tank
 2013-02-27.18:51:18 zfs create tank/backup

   The output shows zpool and zfs commands that were executed on the pool
   along with a timestamp. Only commands that alter the pool in some way are
   recorded. Commands like zfs list are not included. When no pool name is
   specified, the history of all pools is displayed.

   zpool history can show even more information when the options -i or -l are
   provided. -i displays user-initiated events as well as internally logged
   ZFS events.

 # zpool history -i
 History for 'tank':
 2013-02-26.23:02:35 [internal pool create txg:5] pool spa 28; zfs spa 28; zpl 5;uts  9.1-RELEASE 901000 amd64
 2013-02-27.18:50:53 [internal property set txg:50] atime=0 dataset = 21
 2013-02-27.18:50:58 zfs set atime=off tank
 2013-02-27.18:51:04 [internal property set txg:53] checksum=7 dataset = 21
 2013-02-27.18:51:09 zfs set checksum=fletcher4 tank
 2013-02-27.18:51:13 [internal create txg:55] dataset = 39
 2013-02-27.18:51:18 zfs create tank/backup

   More details can be shown by adding -l. History records are shown in a
   long format, including information like the name of the user who issued
   the command and the hostname on which the change was made.

 # zpool history -l
 History for 'tank':
 2013-02-26.23:02:35 zpool create tank mirror /dev/ada0 /dev/ada1 [user 0 (root) on :global]
 2013-02-27.18:50:58 zfs set atime=off tank [user 0 (root) on myzfsbox:global]
 2013-02-27.18:51:09 zfs set checksum=fletcher4 tank [user 0 (root) on myzfsbox:global]
 2013-02-27.18:51:18 zfs create tank/backup [user 0 (root) on myzfsbox:global]

   The output shows that the root user created the mirrored pool with disks
   /dev/ada0 and /dev/ada1. The hostname myzfsbox is also shown in the
   commands after the pool's creation. The hostname display becomes important
   when the pool is exported from one system and imported on another. The
   commands that are issued on the other system can clearly be distinguished
   by the hostname that is recorded for each command.

   Both options to zpool history can be combined to give the most detailed
   information possible for any given pool. Pool history provides valuable
   information when tracking down the actions that were performed or when
   more detailed output is needed for debugging.

  20.3.13. Performance Monitoring

   A built-in monitoring system can display pool I/O statistics in real time.
   It shows the amount of free and used space on the pool, how many read and
   write operations are being performed per second, and how much I/O
   bandwidth is currently being utilized. By default, all pools in the system
   are monitored and displayed. A pool name can be provided to limit
   monitoring to just that pool. A basic example:

 # zpool iostat
                capacity     operations    bandwidth
 pool        alloc   free   read  write   read  write
 ----------  -----  -----  -----  -----  -----  -----
 data         288G  1.53T      2     11  11.3K  57.1K

   To continuously monitor I/O activity, a number can be specified as the
   last parameter, indicating a interval in seconds to wait between updates.
   The next statistic line is printed after each interval. Press Ctrl+C to
   stop this continuous monitoring. Alternatively, give a second number on
   the command line after the interval to specify the total number of
   statistics to display.

   Even more detailed I/O statistics can be displayed with -v. Each device in
   the pool is shown with a statistics line. This is useful in seeing how
   many read and write operations are being performed on each device, and can
   help determine if any individual device is slowing down the pool. This
   example shows a mirrored pool with two devices:

 # zpool iostat -v
                             capacity     operations    bandwidth
 pool                     alloc   free   read  write   read  write
 -----------------------  -----  -----  -----  -----  -----  -----
 data                      288G  1.53T      2     12  9.23K  61.5K
   mirror                  288G  1.53T      2     12  9.23K  61.5K
     ada1                     -      -      0      4  5.61K  61.7K
     ada2                     -      -      1      4  5.04K  61.7K
 -----------------------  -----  -----  -----  -----  -----  -----

  20.3.14. Splitting a Storage Pool

   A pool consisting of one or more mirror vdevs can be split into two pools.
   Unless otherwise specified, the last member of each mirror is detached and
   used to create a new pool containing the same data. The operation should
   first be attempted with -n. The details of the proposed operation are
   displayed without it actually being performed. This helps confirm that the
   operation will do what the user intends.

20.4. zfs Administration

   The zfs utility is responsible for creating, destroying, and managing all
   ZFS datasets that exist within a pool. The pool is managed using zpool.

  20.4.1. Creating and Destroying Datasets

   Unlike traditional disks and volume managers, space in ZFS is not
   preallocated. With traditional file systems, after all of the space is
   partitioned and assigned, there is no way to add an additional file system
   without adding a new disk. With ZFS, new file systems can be created at
   any time. Each dataset has properties including features like compression,
   deduplication, caching, and quotas, as well as other useful properties
   like readonly, case sensitivity, network file sharing, and a mount point.
   Datasets can be nested inside each other, and child datasets will inherit
   properties from their parents. Each dataset can be administered,
   delegated, replicated, snapshotted, jailed, and destroyed as a unit. There
   are many advantages to creating a separate dataset for each different type
   or set of files. The only drawbacks to having an extremely large number of
   datasets is that some commands like zfs list will be slower, and the
   mounting of hundreds or even thousands of datasets can slow the FreeBSD
   boot process.

   Create a new dataset and enable LZ4 compression on it:

 # zfs list
 NAME                  USED  AVAIL  REFER  MOUNTPOINT
 mypool                781M  93.2G   144K  none
 mypool/ROOT           777M  93.2G   144K  none
 mypool/ROOT/default   777M  93.2G   777M  /
 mypool/tmp            176K  93.2G   176K  /tmp
 mypool/usr            616K  93.2G   144K  /usr
 mypool/usr/home       184K  93.2G   184K  /usr/home
 mypool/usr/ports      144K  93.2G   144K  /usr/ports
 mypool/usr/src        144K  93.2G   144K  /usr/src
 mypool/var           1.20M  93.2G   608K  /var
 mypool/var/crash      148K  93.2G   148K  /var/crash
 mypool/var/log        178K  93.2G   178K  /var/log
 mypool/var/mail       144K  93.2G   144K  /var/mail
 mypool/var/tmp        152K  93.2G   152K  /var/tmp
 # zfs create -o compress=lz4 mypool/usr/mydataset
 # zfs list
 NAME                   USED  AVAIL  REFER  MOUNTPOINT
 mypool                 781M  93.2G   144K  none
 mypool/ROOT            777M  93.2G   144K  none
 mypool/ROOT/default    777M  93.2G   777M  /
 mypool/tmp             176K  93.2G   176K  /tmp
 mypool/usr             704K  93.2G   144K  /usr
 mypool/usr/home        184K  93.2G   184K  /usr/home
 mypool/usr/mydataset  87.5K  93.2G  87.5K  /usr/mydataset
 mypool/usr/ports       144K  93.2G   144K  /usr/ports
 mypool/usr/src         144K  93.2G   144K  /usr/src
 mypool/var            1.20M  93.2G   610K  /var
 mypool/var/crash       148K  93.2G   148K  /var/crash
 mypool/var/log         178K  93.2G   178K  /var/log
 mypool/var/mail        144K  93.2G   144K  /var/mail
 mypool/var/tmp         152K  93.2G   152K  /var/tmp

   Destroying a dataset is much quicker than deleting all of the files that
   reside on the dataset, as it does not involve scanning all of the files
   and updating all of the corresponding metadata.

   Destroy the previously-created dataset:

 # zfs list
 NAME                   USED  AVAIL  REFER  MOUNTPOINT
 mypool                 880M  93.1G   144K  none
 mypool/ROOT            777M  93.1G   144K  none
 mypool/ROOT/default    777M  93.1G   777M  /
 mypool/tmp             176K  93.1G   176K  /tmp
 mypool/usr             101M  93.1G   144K  /usr
 mypool/usr/home        184K  93.1G   184K  /usr/home
 mypool/usr/mydataset   100M  93.1G   100M  /usr/mydataset
 mypool/usr/ports       144K  93.1G   144K  /usr/ports
 mypool/usr/src         144K  93.1G   144K  /usr/src
 mypool/var            1.20M  93.1G   610K  /var
 mypool/var/crash       148K  93.1G   148K  /var/crash
 mypool/var/log         178K  93.1G   178K  /var/log
 mypool/var/mail        144K  93.1G   144K  /var/mail
 mypool/var/tmp         152K  93.1G   152K  /var/tmp
 # zfs destroy mypool/usr/mydataset
 # zfs list
 NAME                  USED  AVAIL  REFER  MOUNTPOINT
 mypool                781M  93.2G   144K  none
 mypool/ROOT           777M  93.2G   144K  none
 mypool/ROOT/default   777M  93.2G   777M  /
 mypool/tmp            176K  93.2G   176K  /tmp
 mypool/usr            616K  93.2G   144K  /usr
 mypool/usr/home       184K  93.2G   184K  /usr/home
 mypool/usr/ports      144K  93.2G   144K  /usr/ports
 mypool/usr/src        144K  93.2G   144K  /usr/src
 mypool/var           1.21M  93.2G   612K  /var
 mypool/var/crash      148K  93.2G   148K  /var/crash
 mypool/var/log        178K  93.2G   178K  /var/log
 mypool/var/mail       144K  93.2G   144K  /var/mail
 mypool/var/tmp        152K  93.2G   152K  /var/tmp

   In modern versions of ZFS, zfs destroy is asynchronous, and the free space
   might take several minutes to appear in the pool. Use zpool get freeing
   poolname to see the freeing property, indicating how many datasets are
   having their blocks freed in the background. If there are child datasets,
   like snapshots or other datasets, then the parent cannot be destroyed. To
   destroy a dataset and all of its children, use -r to recursively destroy
   the dataset and all of its children. Use -n -v to list datasets and
   snapshots that would be destroyed by this operation, but do not actually
   destroy anything. Space that would be reclaimed by destruction of
   snapshots is also shown.

  20.4.2. Creating and Destroying Volumes

   A volume is a special type of dataset. Rather than being mounted as a file
   system, it is exposed as a block device under /dev/zvol/poolname/dataset.
   This allows the volume to be used for other file systems, to back the
   disks of a virtual machine, or to be exported using protocols like iSCSI
   or HAST.

   A volume can be formatted with any file system, or used without a file
   system to store raw data. To the user, a volume appears to be a regular
   disk. Putting ordinary file systems on these zvols provides features that
   ordinary disks or file systems do not normally have. For example, using
   the compression property on a 250 MB volume allows creation of a
   compressed FAT file system.

 # zfs create -V 250m -o compression=on tank/fat32
 # zfs list tank
 NAME USED AVAIL REFER MOUNTPOINT
 tank 258M  670M   31K /tank
 # newfs_msdos -F32 /dev/zvol/tank/fat32
 # mount -t msdosfs /dev/zvol/tank/fat32 /mnt
 # df -h /mnt | grep fat32
 Filesystem           Size Used Avail Capacity Mounted on
 /dev/zvol/tank/fat32 249M  24k  249M     0%   /mnt
 # mount | grep fat32
 /dev/zvol/tank/fat32 on /mnt (msdosfs, local)

   Destroying a volume is much the same as destroying a regular file system
   dataset. The operation is nearly instantaneous, but it may take several
   minutes for the free space to be reclaimed in the background.

  20.4.3. Renaming a Dataset

   The name of a dataset can be changed with zfs rename. The parent of a
   dataset can also be changed with this command. Renaming a dataset to be
   under a different parent dataset will change the value of those properties
   that are inherited from the parent dataset. When a dataset is renamed, it
   is unmounted and then remounted in the new location (which is inherited
   from the new parent dataset). This behavior can be prevented with -u.

   Rename a dataset and move it to be under a different parent dataset:

 # zfs list
 NAME                   USED  AVAIL  REFER  MOUNTPOINT
 mypool                 780M  93.2G   144K  none
 mypool/ROOT            777M  93.2G   144K  none
 mypool/ROOT/default    777M  93.2G   777M  /
 mypool/tmp             176K  93.2G   176K  /tmp
 mypool/usr             704K  93.2G   144K  /usr
 mypool/usr/home        184K  93.2G   184K  /usr/home
 mypool/usr/mydataset  87.5K  93.2G  87.5K  /usr/mydataset
 mypool/usr/ports       144K  93.2G   144K  /usr/ports
 mypool/usr/src         144K  93.2G   144K  /usr/src
 mypool/var            1.21M  93.2G   614K  /var
 mypool/var/crash       148K  93.2G   148K  /var/crash
 mypool/var/log         178K  93.2G   178K  /var/log
 mypool/var/mail        144K  93.2G   144K  /var/mail
 mypool/var/tmp         152K  93.2G   152K  /var/tmp
 # zfs rename mypool/usr/mydataset mypool/var/newname
 # zfs list
 NAME                  USED  AVAIL  REFER  MOUNTPOINT
 mypool                780M  93.2G   144K  none
 mypool/ROOT           777M  93.2G   144K  none
 mypool/ROOT/default   777M  93.2G   777M  /
 mypool/tmp            176K  93.2G   176K  /tmp
 mypool/usr            616K  93.2G   144K  /usr
 mypool/usr/home       184K  93.2G   184K  /usr/home
 mypool/usr/ports      144K  93.2G   144K  /usr/ports
 mypool/usr/src        144K  93.2G   144K  /usr/src
 mypool/var           1.29M  93.2G   614K  /var
 mypool/var/crash      148K  93.2G   148K  /var/crash
 mypool/var/log        178K  93.2G   178K  /var/log
 mypool/var/mail       144K  93.2G   144K  /var/mail
 mypool/var/newname   87.5K  93.2G  87.5K  /var/newname
 mypool/var/tmp        152K  93.2G   152K  /var/tmp

   Snapshots can also be renamed like this. Due to the nature of snapshots,
   they cannot be renamed into a different parent dataset. To rename a
   recursive snapshot, specify -r, and all snapshots with the same name in
   child datasets with also be renamed.

 # zfs list -t snapshot
 NAME                                USED  AVAIL  REFER  MOUNTPOINT
 mypool/var/newname@first_snapshot      0      -  87.5K  -
 # zfs rename mypool/var/newname@first_snapshot new_snapshot_name
 # zfs list -t snapshot
 NAME                                   USED  AVAIL  REFER  MOUNTPOINT
 mypool/var/newname@new_snapshot_name      0      -  87.5K  -

  20.4.4. Setting Dataset Properties

   Each ZFS dataset has a number of properties that control its behavior.
   Most properties are automatically inherited from the parent dataset, but
   can be overridden locally. Set a property on a dataset with zfs set
   property=value dataset. Most properties have a limited set of valid
   values, zfs get will display each possible property and valid values. Most
   properties can be reverted to their inherited values using zfs inherit.

   User-defined properties can also be set. They become part of the dataset
   configuration and can be used to provide additional information about the
   dataset or its contents. To distinguish these custom properties from the
   ones supplied as part of ZFS, a colon (:) is used to create a custom
   namespace for the property.

 # zfs set custom:costcenter=1234 tank
 # zfs get custom:costcenter tank
 NAME PROPERTY           VALUE SOURCE
 tank custom:costcenter  1234  local

   To remove a custom property, use zfs inherit with -r. If the custom
   property is not defined in any of the parent datasets, it will be removed
   completely (although the changes are still recorded in the pool's
   history).

 # zfs inherit -r custom:costcenter tank
 # zfs get custom:costcenter tank
 NAME    PROPERTY           VALUE              SOURCE
 tank    custom:costcenter  -                  -
 # zfs get all tank | grep custom:costcenter
 #

    20.4.4.1. Getting and Setting Share Properties

   Two commonly used and useful dataset properties are the NFS and SMB share
   options. Setting these define if and how ZFS datasets may be shared on the
   network. At present, only setting sharing via NFS is supported on FreeBSD.
   To get the current status of a share, enter:

 # zfs get sharenfs mypool/usr/home
 NAME             PROPERTY  VALUE    SOURCE
 mypool/usr/home  sharenfs  on       local
 # zfs get sharesmb mypool/usr/home
 NAME             PROPERTY  VALUE    SOURCE
 mypool/usr/home  sharesmb  off      local

   To enable sharing of a dataset, enter:

 #  zfs set sharenfs=on mypool/usr/home

   It is also possible to set additional options for sharing datasets through
   NFS, such as -alldirs, -maproot and -network. To set additional options to
   a dataset shared through NFS, enter:

 #  zfs set sharenfs="-alldirs,-maproot=root,-network=192.168.1.0/24" mypool/usr/home

  20.4.5. Managing Snapshots

   Snapshots are one of the most powerful features of ZFS. A snapshot
   provides a read-only, point-in-time copy of the dataset. With
   Copy-On-Write (COW), snapshots can be created quickly by preserving the
   older version of the data on disk. If no snapshots exist, space is
   reclaimed for future use when data is rewritten or deleted. Snapshots
   preserve disk space by recording only the differences between the current
   dataset and a previous version. Snapshots are allowed only on whole
   datasets, not on individual files or directories. When a snapshot is
   created from a dataset, everything contained in it is duplicated. This
   includes the file system properties, files, directories, permissions, and
   so on. Snapshots use no additional space when they are first created, only
   consuming space as the blocks they reference are changed. Recursive
   snapshots taken with -r create a snapshot with the same name on the
   dataset and all of its children, providing a consistent moment-in-time
   snapshot of all of the file systems. This can be important when an
   application has files on multiple datasets that are related or dependent
   upon each other. Without snapshots, a backup would have copies of the
   files from different points in time.

   Snapshots in ZFS provide a variety of features that even other file
   systems with snapshot functionality lack. A typical example of snapshot
   use is to have a quick way of backing up the current state of the file
   system when a risky action like a software installation or a system
   upgrade is performed. If the action fails, the snapshot can be rolled back
   and the system has the same state as when the snapshot was created. If the
   upgrade was successful, the snapshot can be deleted to free up space.
   Without snapshots, a failed upgrade often requires a restore from backup,
   which is tedious, time consuming, and may require downtime during which
   the system cannot be used. Snapshots can be rolled back quickly, even
   while the system is running in normal operation, with little or no
   downtime. The time savings are enormous with multi-terabyte storage
   systems and the time required to copy the data from backup. Snapshots are
   not a replacement for a complete backup of a pool, but can be used as a
   quick and easy way to store a copy of the dataset at a specific point in
   time.

    20.4.5.1. Creating Snapshots

   Snapshots are created with zfs snapshot dataset@snapshotname. Adding -r
   creates a snapshot recursively, with the same name on all child datasets.

   Create a recursive snapshot of the entire pool:

 # zfs list -t all
 NAME                                   USED  AVAIL  REFER  MOUNTPOINT
 mypool                                 780M  93.2G   144K  none
 mypool/ROOT                            777M  93.2G   144K  none
 mypool/ROOT/default                    777M  93.2G   777M  /
 mypool/tmp                             176K  93.2G   176K  /tmp
 mypool/usr                             616K  93.2G   144K  /usr
 mypool/usr/home                        184K  93.2G   184K  /usr/home
 mypool/usr/ports                       144K  93.2G   144K  /usr/ports
 mypool/usr/src                         144K  93.2G   144K  /usr/src
 mypool/var                            1.29M  93.2G   616K  /var
 mypool/var/crash                       148K  93.2G   148K  /var/crash
 mypool/var/log                         178K  93.2G   178K  /var/log
 mypool/var/mail                        144K  93.2G   144K  /var/mail
 mypool/var/newname                    87.5K  93.2G  87.5K  /var/newname
 mypool/var/newname@new_snapshot_name      0      -  87.5K  -
 mypool/var/tmp                         152K  93.2G   152K  /var/tmp
 # zfs snapshot -r mypool@my_recursive_snapshot
 # zfs list -t snapshot
 NAME                                        USED  AVAIL  REFER  MOUNTPOINT
 mypool@my_recursive_snapshot                   0      -   144K  -
 mypool/ROOT@my_recursive_snapshot              0      -   144K  -
 mypool/ROOT/default@my_recursive_snapshot      0      -   777M  -
 mypool/tmp@my_recursive_snapshot               0      -   176K  -
 mypool/usr@my_recursive_snapshot               0      -   144K  -
 mypool/usr/home@my_recursive_snapshot          0      -   184K  -
 mypool/usr/ports@my_recursive_snapshot         0      -   144K  -
 mypool/usr/src@my_recursive_snapshot           0      -   144K  -
 mypool/var@my_recursive_snapshot               0      -   616K  -
 mypool/var/crash@my_recursive_snapshot         0      -   148K  -
 mypool/var/log@my_recursive_snapshot           0      -   178K  -
 mypool/var/mail@my_recursive_snapshot          0      -   144K  -
 mypool/var/newname@new_snapshot_name           0      -  87.5K  -
 mypool/var/newname@my_recursive_snapshot       0      -  87.5K  -
 mypool/var/tmp@my_recursive_snapshot           0      -   152K  -

   Snapshots are not shown by a normal zfs list operation. To list snapshots,
   -t snapshot is appended to zfs list. -t all displays both file systems and
   snapshots.

   Snapshots are not mounted directly, so no path is shown in the MOUNTPOINT
   column. There is no mention of available disk space in the AVAIL column,
   as snapshots cannot be written to after they are created. Compare the
   snapshot to the original dataset from which it was created:

 # zfs list -rt all mypool/usr/home
 NAME                                    USED  AVAIL  REFER  MOUNTPOINT
 mypool/usr/home                         184K  93.2G   184K  /usr/home
 mypool/usr/home@my_recursive_snapshot      0      -   184K  -

   Displaying both the dataset and the snapshot together reveals how
   snapshots work in COW fashion. They save only the changes (delta) that
   were made and not the complete file system contents all over again. This
   means that snapshots take little space when few changes are made. Space
   usage can be made even more apparent by copying a file to the dataset,
   then making a second snapshot:

 # cp /etc/passwd /var/tmp
 # zfs snapshot mypool/var/tmp@after_cp
 # zfs list -rt all mypool/var/tmp
 NAME                                   USED  AVAIL  REFER  MOUNTPOINT
 mypool/var/tmp                         206K  93.2G   118K  /var/tmp
 mypool/var/tmp@my_recursive_snapshot    88K      -   152K  -
 mypool/var/tmp@after_cp                   0      -   118K  -

   The second snapshot contains only the changes to the dataset after the
   copy operation. This yields enormous space savings. Notice that the size
   of the snapshot mypool/var/tmp@my_recursive_snapshot also changed in the
   USED column to indicate the changes between itself and the snapshot taken
   afterwards.

    20.4.5.2. Comparing Snapshots

   ZFS provides a built-in command to compare the differences in content
   between two snapshots. This is helpful when many snapshots were taken over
   time and the user wants to see how the file system has changed over time.
   For example, zfs diff lets a user find the latest snapshot that still
   contains a file that was accidentally deleted. Doing this for the two
   snapshots that were created in the previous section yields this output:

 # zfs list -rt all mypool/var/tmp
 NAME                                   USED  AVAIL  REFER  MOUNTPOINT
 mypool/var/tmp                         206K  93.2G   118K  /var/tmp
 mypool/var/tmp@my_recursive_snapshot    88K      -   152K  -
 mypool/var/tmp@after_cp                   0      -   118K  -
 # zfs diff mypool/var/tmp@my_recursive_snapshot
 M       /var/tmp/
 +       /var/tmp/passwd

   The command lists the changes between the specified snapshot (in this case
   mypool/var/tmp@my_recursive_snapshot) and the live file system. The first
   column shows the type of change:

   +------------------------------------------------------------------------+
   | +                   | The path or file was added.                      |
   |---------------------+--------------------------------------------------|
   | -                   | The path or file was deleted.                    |
   |---------------------+--------------------------------------------------|
   | M                   | The path or file was modified.                   |
   |---------------------+--------------------------------------------------|
   | R                   | The path or file was renamed.                    |
   +------------------------------------------------------------------------+

   Comparing the output with the table, it becomes clear that passwd was
   added after the snapshot mypool/var/tmp@my_recursive_snapshot was created.
   This also resulted in a modification to the parent directory mounted at
   /var/tmp.

   Comparing two snapshots is helpful when using the ZFS replication feature
   to transfer a dataset to a different host for backup purposes.

   Compare two snapshots by providing the full dataset name and snapshot name
   of both datasets:

 # cp /var/tmp/passwd /var/tmp/passwd.copy
 # zfs snapshot mypool/var/tmp@diff_snapshot
 # zfs diff mypool/var/tmp@my_recursive_snapshot mypool/var/tmp@diff_snapshot
 M       /var/tmp/
 +       /var/tmp/passwd
 +       /var/tmp/passwd.copy
 # zfs diff mypool/var/tmp@my_recursive_snapshot mypool/var/tmp@after_cp
 M       /var/tmp/
 +       /var/tmp/passwd

   A backup administrator can compare two snapshots received from the sending
   host and determine the actual changes in the dataset. See the Replication
   section for more information.

    20.4.5.3. Snapshot Rollback

   When at least one snapshot is available, it can be rolled back to at any
   time. Most of the time this is the case when the current state of the
   dataset is no longer required and an older version is preferred. Scenarios
   such as local development tests have gone wrong, botched system updates
   hampering the system's overall functionality, or the requirement to
   restore accidentally deleted files or directories are all too common
   occurrences. Luckily, rolling back a snapshot is just as easy as typing
   zfs rollback snapshotname. Depending on how many changes are involved, the
   operation will finish in a certain amount of time. During that time, the
   dataset always remains in a consistent state, much like a database that
   conforms to ACID principles is performing a rollback. This is happening
   while the dataset is live and accessible without requiring a downtime.
   Once the snapshot has been rolled back, the dataset has the same state as
   it had when the snapshot was originally taken. All other data in that
   dataset that was not part of the snapshot is discarded. Taking a snapshot
   of the current state of the dataset before rolling back to a previous one
   is a good idea when some data is required later. This way, the user can
   roll back and forth between snapshots without losing data that is still
   valuable.

   In the first example, a snapshot is rolled back because of a careless rm
   operation that removes too much data than was intended.

 # zfs list -rt all mypool/var/tmp
 NAME                                   USED  AVAIL  REFER  MOUNTPOINT
 mypool/var/tmp                         262K  93.2G   120K  /var/tmp
 mypool/var/tmp@my_recursive_snapshot    88K      -   152K  -
 mypool/var/tmp@after_cp               53.5K      -   118K  -
 mypool/var/tmp@diff_snapshot              0      -   120K  -
 # ls /var/tmp
 passwd          passwd.copy     vi.recover
 # rm /var/tmp/passwd*
 # ls /var/tmp
 vi.recover

   At this point, the user realized that too many files were deleted and
   wants them back. ZFS provides an easy way to get them back using
   rollbacks, but only when snapshots of important data are performed on a
   regular basis. To get the files back and start over from the last
   snapshot, issue the command:

 # zfs rollback mypool/var/tmp@diff_snapshot
 # ls /var/tmp
 passwd          passwd.copy     vi.recover

   The rollback operation restored the dataset to the state of the last
   snapshot. It is also possible to roll back to a snapshot that was taken
   much earlier and has other snapshots that were created after it. When
   trying to do this, ZFS will issue this warning:

 # zfs list -rt snapshot mypool/var/tmp
 AME                                   USED  AVAIL  REFER  MOUNTPOINT
 mypool/var/tmp@my_recursive_snapshot    88K      -   152K  -
 mypool/var/tmp@after_cp               53.5K      -   118K  -
 mypool/var/tmp@diff_snapshot              0      -   120K  -
 # zfs rollback mypool/var/tmp@my_recursive_snapshot
 cannot rollback to 'mypool/var/tmp@my_recursive_snapshot': more recent snapshots exist
 use '-r' to force deletion of the following snapshots:
 mypool/var/tmp@after_cp
 mypool/var/tmp@diff_snapshot

   This warning means that snapshots exist between the current state of the
   dataset and the snapshot to which the user wants to roll back. To complete
   the rollback, these snapshots must be deleted. ZFS cannot track all the
   changes between different states of the dataset, because snapshots are
   read-only. ZFS will not delete the affected snapshots unless the user
   specifies -r to indicate that this is the desired action. If that is the
   intention, and the consequences of losing all intermediate snapshots is
   understood, the command can be issued:

 # zfs rollback -r mypool/var/tmp@my_recursive_snapshot
 # zfs list -rt snapshot mypool/var/tmp
 NAME                                   USED  AVAIL  REFER  MOUNTPOINT
 mypool/var/tmp@my_recursive_snapshot     8K      -   152K  -
 # ls /var/tmp
 vi.recover

   The output from zfs list -t snapshot confirms that the intermediate
   snapshots were removed as a result of zfs rollback -r.

    20.4.5.4. Restoring Individual Files from Snapshots

   Snapshots are mounted in a hidden directory under the parent dataset:
   .zfs/snapshots/snapshotname. By default, these directories will not be
   displayed even when a standard ls -a is issued. Although the directory is
   not displayed, it is there nevertheless and can be accessed like any
   normal directory. The property named snapdir controls whether these hidden
   directories show up in a directory listing. Setting the property to
   visible allows them to appear in the output of ls and other commands that
   deal with directory contents.

 # zfs get snapdir mypool/var/tmp
 NAME            PROPERTY  VALUE    SOURCE
 mypool/var/tmp  snapdir   hidden   default
 # ls -a /var/tmp
 .               ..              passwd          vi.recover
 # zfs set snapdir=visible mypool/var/tmp
 # ls -a /var/tmp
 .               ..              .zfs            passwd          vi.recover

   Individual files can easily be restored to a previous state by copying
   them from the snapshot back to the parent dataset. The directory structure
   below .zfs/snapshot has a directory named exactly like the snapshots taken
   earlier to make it easier to identify them. In the next example, it is
   assumed that a file is to be restored from the hidden .zfs directory by
   copying it from the snapshot that contained the latest version of the
   file:

 # rm /var/tmp/passwd
 # ls -a /var/tmp
 .               ..              .zfs            vi.recover
 # ls /var/tmp/.zfs/snapshot
 after_cp                my_recursive_snapshot
 # ls /var/tmp/.zfs/snapshot/after_cp
 passwd          vi.recover
 # cp /var/tmp/.zfs/snapshot/after_cp/passwd /var/tmp

   When ls .zfs/snapshot was issued, the snapdir property might have been set
   to hidden, but it would still be possible to list the contents of that
   directory. It is up to the administrator to decide whether these
   directories will be displayed. It is possible to display these for certain
   datasets and prevent it for others. Copying files or directories from this
   hidden .zfs/snapshot is simple enough. Trying it the other way around
   results in this error:

 # cp /etc/rc.conf /var/tmp/.zfs/snapshot/after_cp/
 cp: /var/tmp/.zfs/snapshot/after_cp/rc.conf: Read-only file system

   The error reminds the user that snapshots are read-only and cannot be
   changed after creation. Files cannot be copied into or removed from
   snapshot directories because that would change the state of the dataset
   they represent.

   Snapshots consume space based on how much the parent file system has
   changed since the time of the snapshot. The written property of a snapshot
   tracks how much space is being used by the snapshot.

   Snapshots are destroyed and the space reclaimed with zfs destroy
   dataset@snapshot. Adding -r recursively removes all snapshots with the
   same name under the parent dataset. Adding -n -v to the command displays a
   list of the snapshots that would be deleted and an estimate of how much
   space would be reclaimed without performing the actual destroy operation.

  20.4.6. Managing Clones

   A clone is a copy of a snapshot that is treated more like a regular
   dataset. Unlike a snapshot, a clone is not read only, is mounted, and can
   have its own properties. Once a clone has been created using zfs clone,
   the snapshot it was created from cannot be destroyed. The child/parent
   relationship between the clone and the snapshot can be reversed using zfs
   promote. After a clone has been promoted, the snapshot becomes a child of
   the clone, rather than of the original parent dataset. This will change
   how the space is accounted, but not actually change the amount of space
   consumed. The clone can be mounted at any point within the ZFS file system
   hierarchy, not just below the original location of the snapshot.

   To demonstrate the clone feature, this example dataset is used:

 # zfs list -rt all camino/home/joe
 NAME                    USED  AVAIL  REFER  MOUNTPOINT
 camino/home/joe         108K   1.3G    87K  /usr/home/joe
 camino/home/joe@plans    21K      -  85.5K  -
 camino/home/joe@backup    0K      -    87K  -

   A typical use for clones is to experiment with a specific dataset while
   keeping the snapshot around to fall back to in case something goes wrong.
   Since snapshots cannot be changed, a read/write clone of a snapshot is
   created. After the desired result is achieved in the clone, the clone can
   be promoted to a dataset and the old file system removed. This is not
   strictly necessary, as the clone and dataset can coexist without problems.

 # zfs clone camino/home/joe@backup camino/home/joenew
 # ls /usr/home/joe*
 /usr/home/joe:
 backup.txz     plans.txt

 /usr/home/joenew:
 backup.txz     plans.txt
 # df -h /usr/home
 Filesystem          Size    Used   Avail Capacity  Mounted on
 usr/home/joe        1.3G     31k    1.3G     0%    /usr/home/joe
 usr/home/joenew     1.3G     31k    1.3G     0%    /usr/home/joenew

   After a clone is created it is an exact copy of the state the dataset was
   in when the snapshot was taken. The clone can now be changed independently
   from its originating dataset. The only connection between the two is the
   snapshot. ZFS records this connection in the property origin. Once the
   dependency between the snapshot and the clone has been removed by
   promoting the clone using zfs promote, the origin of the clone is removed
   as it is now an independent dataset. This example demonstrates it:

 # zfs get origin camino/home/joenew
 NAME                  PROPERTY  VALUE                     SOURCE
 camino/home/joenew    origin    camino/home/joe@backup    -
 # zfs promote camino/home/joenew
 # zfs get origin camino/home/joenew
 NAME                  PROPERTY  VALUE   SOURCE
 camino/home/joenew    origin    -       -

   After making some changes like copying loader.conf to the promoted clone,
   for example, the old directory becomes obsolete in this case. Instead, the
   promoted clone can replace it. This can be achieved by two consecutive
   commands: zfs destroy on the old dataset and zfs rename on the clone to
   name it like the old dataset (it could also get an entirely different
   name).

 # cp /boot/defaults/loader.conf /usr/home/joenew
 # zfs destroy -f camino/home/joe
 # zfs rename camino/home/joenew camino/home/joe
 # ls /usr/home/joe
 backup.txz     loader.conf     plans.txt
 # df -h /usr/home
 Filesystem          Size    Used   Avail Capacity  Mounted on
 usr/home/joe        1.3G    128k    1.3G     0%    /usr/home/joe

   The cloned snapshot is now handled like an ordinary dataset. It contains
   all the data from the original snapshot plus the files that were added to
   it like loader.conf. Clones can be used in different scenarios to provide
   useful features to ZFS users. For example, jails could be provided as
   snapshots containing different sets of installed applications. Users can
   clone these snapshots and add their own applications as they see fit. Once
   they are satisfied with the changes, the clones can be promoted to full
   datasets and provided to end users to work with like they would with a
   real dataset. This saves time and administrative overhead when providing
   these jails.

  20.4.7. Replication

   Keeping data on a single pool in one location exposes it to risks like
   theft and natural or human disasters. Making regular backups of the entire
   pool is vital. ZFS provides a built-in serialization feature that can send
   a stream representation of the data to standard output. Using this
   technique, it is possible to not only store the data on another pool
   connected to the local system, but also to send it over a network to
   another system. Snapshots are the basis for this replication (see the
   section on ZFS snapshots). The commands used for replicating data are zfs
   send and zfs receive.

   These examples demonstrate ZFS replication with these two pools:

 # zpool list
 NAME    SIZE  ALLOC   FREE   CKPOINT  EXPANDSZ   FRAG   CAP  DEDUP  HEALTH  ALTROOT
 backup  960M    77K   896M         -         -     0%    0%  1.00x  ONLINE  -
 mypool  984M  43.7M   940M         -         -     0%    4%  1.00x  ONLINE  -

   The pool named mypool is the primary pool where data is written to and
   read from on a regular basis. A second pool, backup is used as a standby
   in case the primary pool becomes unavailable. Note that this fail-over is
   not done automatically by ZFS, but must be manually done by a system
   administrator when needed. A snapshot is used to provide a consistent
   version of the file system to be replicated. Once a snapshot of mypool has
   been created, it can be copied to the backup pool. Only snapshots can be
   replicated. Changes made since the most recent snapshot will not be
   included.

 # zfs snapshot mypool@backup1
 # zfs list -t snapshot
 NAME                    USED  AVAIL  REFER  MOUNTPOINT
 mypool@backup1             0      -  43.6M  -

   Now that a snapshot exists, zfs send can be used to create a stream
   representing the contents of the snapshot. This stream can be stored as a
   file or received by another pool. The stream is written to standard
   output, but must be redirected to a file or pipe or an error is produced:

 # zfs send mypool@backup1
 Error: Stream can not be written to a terminal.
 You must redirect standard output.

   To back up a dataset with zfs send, redirect to a file located on the
   mounted backup pool. Ensure that the pool has enough free space to
   accommodate the size of the snapshot being sent, which means all of the
   data contained in the snapshot, not just the changes from the previous
   snapshot.

 # zfs send mypool@backup1 > /backup/backup1
 # zpool list
 NAME    SIZE  ALLOC   FREE   CKPOINT  EXPANDSZ   FRAG    CAP  DEDUP  HEALTH  ALTROOT
 backup  960M  63.7M   896M         -         -     0%     6%  1.00x  ONLINE  -
 mypool  984M  43.7M   940M         -         -     0%     4%  1.00x  ONLINE  -

   The zfs send transferred all the data in the snapshot called backup1 to
   the pool named backup. Creating and sending these snapshots can be done
   automatically with a cron(8) job.

   Instead of storing the backups as archive files, ZFS can receive them as a
   live file system, allowing the backed up data to be accessed directly. To
   get to the actual data contained in those streams, zfs receive is used to
   transform the streams back into files and directories. The example below
   combines zfs send and zfs receive using a pipe to copy the data from one
   pool to another. The data can be used directly on the receiving pool after
   the transfer is complete. A dataset can only be replicated to an empty
   dataset.

 # zfs snapshot mypool@replica1
 # zfs send -v mypool@replica1 | zfs receive backup/mypool
 send from @ to mypool@replica1 estimated size is 50.1M
 total estimated size is 50.1M
 TIME        SENT   SNAPSHOT

 # zpool list
 NAME    SIZE  ALLOC   FREE   CKPOINT  EXPANDSZ   FRAG    CAP  DEDUP  HEALTH  ALTROOT
 backup  960M  63.7M   896M         -         -     0%     6%  1.00x  ONLINE  -
 mypool  984M  43.7M   940M         -         -     0%     4%  1.00x  ONLINE  -

    20.4.7.1. Incremental Backups

   zfs send can also determine the difference between two snapshots and send
   only the differences between the two. This saves disk space and transfer
   time. For example:

 # zfs snapshot mypool@replica2
 # zfs list -t snapshot
 NAME                    USED  AVAIL  REFER  MOUNTPOINT
 mypool@replica1         5.72M      -  43.6M  -
 mypool@replica2             0      -  44.1M  -
 # zpool list
 NAME    SIZE  ALLOC   FREE   CKPOINT  EXPANDSZ   FRAG   CAP  DEDUP  HEALTH  ALTROOT
 backup  960M  61.7M   898M         -         -     0%    6%  1.00x  ONLINE  -
 mypool  960M  50.2M   910M         -         -     0%    5%  1.00x  ONLINE  -

   A second snapshot called replica2 was created. This second snapshot
   contains only the changes that were made to the file system between now
   and the previous snapshot, replica1. Using zfs send -i and indicating the
   pair of snapshots generates an incremental replica stream containing only
   the data that has changed. This can only succeed if the initial snapshot
   already exists on the receiving side.

 # zfs send -v -i mypool@replica1 mypool@replica2 | zfs receive /backup/mypool
 send from @replica1 to mypool@replica2 estimated size is 5.02M
 total estimated size is 5.02M
 TIME        SENT   SNAPSHOT

 # zpool list
 NAME    SIZE  ALLOC   FREE   CKPOINT  EXPANDSZ   FRAG  CAP  DEDUP  HEALTH  ALTROOT
 backup  960M  80.8M   879M         -         -     0%   8%  1.00x  ONLINE  -
 mypool  960M  50.2M   910M         -         -     0%   5%  1.00x  ONLINE  -

 # zfs list
 NAME                         USED  AVAIL  REFER  MOUNTPOINT
 backup                      55.4M   240G   152K  /backup
 backup/mypool               55.3M   240G  55.2M  /backup/mypool
 mypool                      55.6M  11.6G  55.0M  /mypool

 # zfs list -t snapshot
 NAME                                         USED  AVAIL  REFER  MOUNTPOINT
 backup/mypool@replica1                       104K      -  50.2M  -
 backup/mypool@replica2                          0      -  55.2M  -
 mypool@replica1                             29.9K      -  50.0M  -
 mypool@replica2                                 0      -  55.0M  -

   The incremental stream was successfully transferred. Only the data that
   had changed was replicated, rather than the entirety of replica1. Only the
   differences were sent, which took much less time to transfer and saved
   disk space by not copying the complete pool each time. This is useful when
   having to rely on slow networks or when costs per transferred byte must be
   considered.

   A new file system, backup/mypool, is available with all of the files and
   data from the pool mypool. If -P is specified, the properties of the
   dataset will be copied, including compression settings, quotas, and mount
   points. When -R is specified, all child datasets of the indicated dataset
   will be copied, along with all of their properties. Sending and receiving
   can be automated so that regular backups are created on the second pool.

    20.4.7.2. Sending Encrypted Backups over SSH

   Sending streams over the network is a good way to keep a remote backup,
   but it does come with a drawback. Data sent over the network link is not
   encrypted, allowing anyone to intercept and transform the streams back
   into data without the knowledge of the sending user. This is undesirable,
   especially when sending the streams over the internet to a remote host.
   SSH can be used to securely encrypt data send over a network connection.
   Since ZFS only requires the stream to be redirected from standard output,
   it is relatively easy to pipe it through SSH. To keep the contents of the
   file system encrypted in transit and on the remote system, consider using
   PEFS.

   A few settings and security precautions must be completed first. Only the
   necessary steps required for the zfs send operation are shown here. For
   more information on SSH, see Section 14.8, "OpenSSH".

   This configuration is required:

     * Passwordless SSH access between sending and receiving host using SSH
       keys

     * Normally, the privileges of the root user are needed to send and
       receive streams. This requires logging in to the receiving system as
       root. However, logging in as root is disabled by default for security
       reasons. The ZFS Delegation system can be used to allow a non-root
       user on each system to perform the respective send and receive
       operations.

     * On the sending system:

 # zfs allow -u someuser send,snapshot mypool

     * To mount the pool, the unprivileged user must own the directory, and
       regular users must be allowed to mount file systems. On the receiving
       system:

 # sysctl vfs.usermount=1
 vfs.usermount: 0 -> 1
 # echo vfs.usermount=1 >> /etc/sysctl.conf
 # zfs create recvpool/backup
 # zfs allow -u someuser create,mount,receive recvpool/backup
 # chown someuser /recvpool/backup

   The unprivileged user now has the ability to receive and mount datasets,
   and the home dataset can be replicated to the remote system:

 % zfs snapshot -r mypool/home@monday
 % zfs send -R mypool/home@monday | ssh someuser@backuphost zfs recv -dvu recvpool/backup

   A recursive snapshot called monday is made of the file system dataset home
   that resides on the pool mypool. Then it is sent with zfs send -R to
   include the dataset, all child datasets, snapshots, clones, and settings
   in the stream. The output is piped to the waiting zfs receive on the
   remote host backuphost through SSH. Using a fully qualified domain name or
   IP address is recommended. The receiving machine writes the data to the
   backup dataset on the recvpool pool. Adding -d to zfs recv overwrites the
   name of the pool on the receiving side with the name of the snapshot. -u
   causes the file systems to not be mounted on the receiving side. When -v
   is included, more detail about the transfer is shown, including elapsed
   time and the amount of data transferred.

  20.4.8. Dataset, User, and Group Quotas

   Dataset quotas are used to restrict the amount of space that can be
   consumed by a particular dataset. Reference Quotas work in very much the
   same way, but only count the space used by the dataset itself, excluding
   snapshots and child datasets. Similarly, user and group quotas can be used
   to prevent users or groups from using all of the space in the pool or
   dataset.

   The following examples assume that the users already exist in the system.
   Before adding a user to the system, make sure to create their home dataset
   first and set the mountpoint to /home/bob. Then, create the user and make
   the home directory point to the dataset's mountpoint location. This will
   properly set owner and group permissions without shadowing any
   pre-existing home directory paths that might exist.

   To enforce a dataset quota of 10 GB for storage/home/bob:

 # zfs set quota=10G storage/home/bob

   To enforce a reference quota of 10 GB for storage/home/bob:

 # zfs set refquota=10G storage/home/bob

   To remove a quota of 10 GB for storage/home/bob:

 # zfs set quota=none storage/home/bob

   The general format is userquota@user=size, and the user's name must be in
   one of these formats:

     * POSIX compatible name such as joe.

     * POSIX numeric ID such as 789.

     * SID name such as joe.bloggs@example.com.

     * SID numeric ID such as S-1-123-456-789.

   For example, to enforce a user quota of 50 GB for the user named joe:

 # zfs set userquota@joe=50G

   To remove any quota:

 # zfs set userquota@joe=none

  Note:

   User quota properties are not displayed by zfs get all. Non-root users can
   only see their own quotas unless they have been granted the userquota
   privilege. Users with this privilege are able to view and set everyone's
   quota.

   The general format for setting a group quota is: groupquota@group=size.

   To set the quota for the group firstgroup to 50 GB, use:

 # zfs set groupquota@firstgroup=50G

   To remove the quota for the group firstgroup, or to make sure that one is
   not set, instead use:

 # zfs set groupquota@firstgroup=none

   As with the user quota property, non-root users can only see the quotas
   associated with the groups to which they belong. However, root or a user
   with the groupquota privilege can view and set all quotas for all groups.

   To display the amount of space used by each user on a file system or
   snapshot along with any quotas, use zfs userspace. For group information,
   use zfs groupspace. For more information about supported options or how to
   display only specific options, refer to zfs(1).

   Users with sufficient privileges, and root, can list the quota for
   storage/home/bob using:

 # zfs get quota storage/home/bob

  20.4.9. Reservations

   Reservations guarantee a minimum amount of space will always be available
   on a dataset. The reserved space will not be available to any other
   dataset. This feature can be especially useful to ensure that free space
   is available for an important dataset or log files.

   The general format of the reservation property is reservation=size, so to
   set a reservation of 10 GB on storage/home/bob, use:

 # zfs set reservation=10G storage/home/bob

   To clear any reservation:

 # zfs set reservation=none storage/home/bob

   The same principle can be applied to the refreservation property for
   setting a Reference Reservation, with the general format
   refreservation=size.

   This command shows any reservations or refreservations that exist on
   storage/home/bob:

 # zfs get reservation storage/home/bob
 # zfs get refreservation storage/home/bob

  20.4.10. Compression

   ZFS provides transparent compression. Compressing data at the block level
   as it is written not only saves space, but can also increase disk
   throughput. If data is compressed by 25%, but the compressed data is
   written to the disk at the same rate as the uncompressed version,
   resulting in an effective write speed of 125%. Compression can also be a
   great alternative to Deduplication because it does not require additional
   memory.

   ZFS offers several different compression algorithms, each with different
   trade-offs. With the introduction of LZ4 compression in ZFS v5000, it is
   possible to enable compression for the entire pool without the large
   performance trade-off of other algorithms. The biggest advantage to LZ4 is
   the early abort feature. If LZ4 does not achieve at least 12.5%
   compression in the first part of the data, the block is written
   uncompressed to avoid wasting CPU cycles trying to compress data that is
   either already compressed or uncompressible. For details about the
   different compression algorithms available in ZFS, see the Compression
   entry in the terminology section.

   The administrator can monitor the effectiveness of compression using a
   number of dataset properties.

 # zfs get used,compressratio,compression,logicalused mypool/compressed_dataset
 NAME        PROPERTY          VALUE     SOURCE
 mypool/compressed_dataset  used              449G      -
 mypool/compressed_dataset  compressratio     1.11x     -
 mypool/compressed_dataset  compression       lz4       local
 mypool/compressed_dataset  logicalused       496G      -

   The dataset is currently using 449 GB of space (the used property).
   Without compression, it would have taken 496 GB of space (the logicalused
   property). This results in the 1.11:1 compression ratio.

   Compression can have an unexpected side effect when combined with User
   Quotas. User quotas restrict how much space a user can consume on a
   dataset, but the measurements are based on how much space is used after
   compression. So if a user has a quota of 10 GB, and writes 10 GB of
   compressible data, they will still be able to store additional data. If
   they later update a file, say a database, with more or less compressible
   data, the amount of space available to them will change. This can result
   in the odd situation where a user did not increase the actual amount of
   data (the logicalused property), but the change in compression caused them
   to reach their quota limit.

   Compression can have a similar unexpected interaction with backups. Quotas
   are often used to limit how much data can be stored to ensure there is
   sufficient backup space available. However since quotas do not consider
   compression, more data may be written than would fit with uncompressed
   backups.

  20.4.11. Zstandard Compression

   In OpenZFS 2.0, a new compression algorithm was added. Zstandard (Zstd)
   offers higher compression ratios than the default LZ4 while offering much
   greater speeds than the alternative, gzip. OpenZFS 2.0 is available
   starting with FreeBSD 12.1-RELEASE via sysutils/openzfs and has been the
   default in FreeBSD 13-CURRENT since September 2020, and will by in
   FreeBSD 13.0-RELEASE.

   Zstd provides a large selection of compression levels, providing
   fine-grained control over performance versus compression ratio. One of the
   main advantages of Zstd is that the decompression speed is independent of
   the compression level. For data that is written once but read many times,
   Zstd allows the use of the highest compression levels without a read
   performance penalty.

   Even when data is updated frequently, there are often performance gains
   that come from enabling compression. One of the biggest advantages comes
   from the compressed ARC feature. ZFS's Adaptive Replacement Cache (ARC)
   caches the compressed version of the data in RAM, decompressing it each
   time it is needed. This allows the same amount of RAM to store more data
   and metadata, increasing the cache hit ratio.

   ZFS offers 19 levels of Zstd compression, each offering incrementally more
   space savings in exchange for slower compression. The default level is
   zstd-3 and offers greater compression than LZ4 without being significantly
   slower. Levels above 10 require significant amounts of memory to compress
   each block, so they are discouraged on systems with less than 16 GB of
   RAM. ZFS also implements a selection of the Zstd fast levels, which get
   correspondingly faster but offer lower compression ratios. ZFS supports
   zstd-fast-1 through zstd-fast-10, zstd-fast-20 through zstd-fast-100 in
   increments of 10, and finally zstd-fast-500 and zstd-fast-1000 which
   provide minimal compression, but offer very high performance.

   If ZFS is not able to allocate the required memory to compress a block
   with Zstd, it will fall back to storing the block uncompressed. This is
   unlikely to happen outside of the highest levels of Zstd on systems that
   are memory constrained. The sysctl kstat.zfs.misc.zstd.compress_alloc_fail
   counts how many times this has occurred since the ZFS module was loaded.

  20.4.12. Deduplication

   When enabled, deduplication uses the checksum of each block to detect
   duplicate blocks. When a new block is a duplicate of an existing block,
   ZFS writes an additional reference to the existing data instead of the
   whole duplicate block. Tremendous space savings are possible if the data
   contains many duplicated files or repeated information. Be warned:
   deduplication requires an extremely large amount of memory, and most of
   the space savings can be had without the extra cost by enabling
   compression instead.

   To activate deduplication, set the dedup property on the target pool:

 # zfs set dedup=on pool

   Only new data being written to the pool will be deduplicated. Data that
   has already been written to the pool will not be deduplicated merely by
   activating this option. A pool with a freshly activated deduplication
   property will look like this example:

 # zpool list
 NAME  SIZE ALLOC  FREE   CKPOINT  EXPANDSZ   FRAG   CAP   DEDUP   HEALTH   ALTROOT
 pool 2.84G 2.19M 2.83G         -         -     0%    0%   1.00x   ONLINE   -

   The DEDUP column shows the actual rate of deduplication for the pool. A
   value of 1.00x shows that data has not been deduplicated yet. In the next
   example, the ports tree is copied three times into different directories
   on the deduplicated pool created above.

 # for d in dir1 dir2 dir3; do
 > mkdir $d && cp -R /usr/ports $d &
 > done

   Redundant data is detected and deduplicated:

 # zpool list
 NAME SIZE  ALLOC  FREE   CKPOINT  EXPANDSZ   FRAG  CAP   DEDUP   HEALTH   ALTROOT
 pool 2.84G 20.9M 2.82G         -         -     0%   0%   3.00x   ONLINE   -

   The DEDUP column shows a factor of 3.00x. Multiple copies of the ports
   tree data was detected and deduplicated, using only a third of the space.
   The potential for space savings can be enormous, but comes at the cost of
   having enough memory to keep track of the deduplicated blocks.

   Deduplication is not always beneficial, especially when the data on a pool
   is not redundant. ZFS can show potential space savings by simulating
   deduplication on an existing pool:

 # zdb -S pool
 Simulated DDT histogram:

 bucket              allocated                       referenced
 ______   ______________________________   ______________________________
 refcnt   blocks   LSIZE   PSIZE   DSIZE   blocks   LSIZE   PSIZE   DSIZE
 ------   ------   -----   -----   -----   ------   -----   -----   -----
      1    2.58M    289G    264G    264G    2.58M    289G    264G    264G
      2     206K   12.6G   10.4G   10.4G     430K   26.4G   21.6G   21.6G
      4    37.6K    692M    276M    276M     170K   3.04G   1.26G   1.26G
      8    2.18K   45.2M   19.4M   19.4M    20.0K    425M    176M    176M
     16      174   2.83M   1.20M   1.20M    3.33K   48.4M   20.4M   20.4M
     32       40   2.17M    222K    222K    1.70K   97.2M   9.91M   9.91M
     64        9     56K   10.5K   10.5K      865   4.96M    948K    948K
    128        2   9.50K      2K      2K      419   2.11M    438K    438K
    256        5   61.5K     12K     12K    1.90K   23.0M   4.47M   4.47M
     1K        2      1K      1K      1K    2.98K   1.49M   1.49M   1.49M
  Total    2.82M    303G    275G    275G    3.20M    319G    287G    287G

 dedup = 1.05, compress = 1.11, copies = 1.00, dedup * compress / copies = 1.16

   After zdb -S finishes analyzing the pool, it shows the space reduction
   ratio that would be achieved by activating deduplication. In this case,
   1.16 is a very poor space saving ratio that is mostly provided by
   compression. Activating deduplication on this pool would not save any
   significant amount of space, and is not worth the amount of memory
   required to enable deduplication. Using the formula ratio = dedup *
   compress / copies, system administrators can plan the storage allocation,
   deciding whether the workload will contain enough duplicate blocks to
   justify the memory requirements. If the data is reasonably compressible,
   the space savings may be very good. Enabling compression first is
   recommended, and compression can also provide greatly increased
   performance. Only enable deduplication in cases where the additional
   savings will be considerable and there is sufficient memory for the DDT.

  20.4.13. ZFS and Jails

   zfs jail and the corresponding jailed property are used to delegate a ZFS
   dataset to a Jail. zfs jail jailid attaches a dataset to the specified
   jail, and zfs unjail detaches it. For the dataset to be controlled from
   within a jail, the jailed property must be set. Once a dataset is jailed,
   it can no longer be mounted on the host because it may have mount points
   that would compromise the security of the host.

20.5. Delegated Administration

   A comprehensive permission delegation system allows unprivileged users to
   perform ZFS administration functions. For example, if each user's home
   directory is a dataset, users can be given permission to create and
   destroy snapshots of their home directories. A backup user can be given
   permission to use replication features. A usage statistics script can be
   allowed to run with access only to the space utilization data for all
   users. It is even possible to delegate the ability to delegate
   permissions. Permission delegation is possible for each subcommand and
   most properties.

  20.5.1. Delegating Dataset Creation

   zfs allow someuser create mydataset gives the specified user permission to
   create child datasets under the selected parent dataset. There is a
   caveat: creating a new dataset involves mounting it. That requires setting
   the FreeBSD vfs.usermount sysctl(8) to 1 to allow non-root users to mount
   a file system. There is another restriction aimed at preventing abuse:
   non-root users must own the mountpoint where the file system is to be
   mounted.

  20.5.2. Delegating Permission Delegation

   zfs allow someuser allow mydataset gives the specified user the ability to
   assign any permission they have on the target dataset, or its children, to
   other users. If a user has the snapshot permission and the allow
   permission, that user can then grant the snapshot permission to other
   users.

20.6. Advanced Topics

  20.6.1. Tuning

   There are a number of tunables that can be adjusted to make ZFS perform
   best for different workloads.

     * vfs.zfs.arc_max - Maximum size of the ARC. The default is all RAM but
       1 GB, or 5/8 of all RAM, whichever is more. However, a lower value
       should be used if the system will be running any other daemons or
       processes that may require memory. This value can be adjusted at
       runtime with sysctl(8) and can be set in /boot/loader.conf or
       /etc/sysctl.conf.

     * vfs.zfs.arc_meta_limit - Limit the portion of the ARC that can be used
       to store metadata. The default is one fourth of vfs.zfs.arc_max.
       Increasing this value will improve performance if the workload
       involves operations on a large number of files and directories, or
       frequent metadata operations, at the cost of less file data fitting in
       the ARC. This value can be adjusted at runtime with sysctl(8) and can
       be set in /boot/loader.conf or /etc/sysctl.conf.

     * vfs.zfs.arc_min - Minimum size of the ARC. The default is one half of
       vfs.zfs.arc_meta_limit. Adjust this value to prevent other
       applications from pressuring out the entire ARC. This value can be
       adjusted at runtime with sysctl(8) and can be set in /boot/loader.conf
       or /etc/sysctl.conf.

     * vfs.zfs.vdev.cache.size - A preallocated amount of memory reserved as
       a cache for each device in the pool. The total amount of memory used
       will be this value multiplied by the number of devices. This value can
       only be adjusted at boot time, and is set in /boot/loader.conf.

     * vfs.zfs.min_auto_ashift - Minimum ashift (sector size) that will be
       used automatically at pool creation time. The value is a power of two.
       The default value of 9 represents 2^9 = 512, a sector size of 512
       bytes. To avoid write amplification and get the best performance, set
       this value to the largest sector size used by a device in the pool.

       Many drives have 4 KB sectors. Using the default ashift of 9 with
       these drives results in write amplification on these devices. Data
       that could be contained in a single 4 KB write must instead be written
       in eight 512-byte writes. ZFS tries to read the native sector size
       from all devices when creating a pool, but many drives with 4 KB
       sectors report that their sectors are 512 bytes for compatibility.
       Setting vfs.zfs.min_auto_ashift to 12 (2^12 = 4096) before creating a
       pool forces ZFS to use 4 KB blocks for best performance on these
       drives.

       Forcing 4 KB blocks is also useful on pools where disk upgrades are
       planned. Future disks are likely to use 4 KB sectors, and ashift
       values cannot be changed after a pool is created.

       In some specific cases, the smaller 512-byte block size might be
       preferable. When used with 512-byte disks for databases, or as storage
       for virtual machines, less data is transferred during small random
       reads. This can provide better performance, especially when using a
       smaller ZFS record size.

     * vfs.zfs.prefetch_disable - Disable prefetch. A value of 0 is enabled
       and 1 is disabled. The default is 0, unless the system has less than
       4 GB of RAM. Prefetch works by reading larger blocks than were
       requested into the ARC in hopes that the data will be needed soon. If
       the workload has a large number of random reads, disabling prefetch
       may actually improve performance by reducing unnecessary reads. This
       value can be adjusted at any time with sysctl(8).

     * vfs.zfs.vdev.trim_on_init - Control whether new devices added to the
       pool have the TRIM command run on them. This ensures the best
       performance and longevity for SSDs, but takes extra time. If the
       device has already been secure erased, disabling this setting will
       make the addition of the new device faster. This value can be adjusted
       at any time with sysctl(8).

     * vfs.zfs.vdev.max_pending - Limit the number of pending I/O requests
       per device. A higher value will keep the device command queue full and
       may give higher throughput. A lower value will reduce latency. This
       value can be adjusted at any time with sysctl(8).

     * vfs.zfs.top_maxinflight - Maxmimum number of outstanding I/Os per
       top-level vdev. Limits the depth of the command queue to prevent high
       latency. The limit is per top-level vdev, meaning the limit applies to
       each mirror, RAID-Z, or other vdev independently. This value can be
       adjusted at any time with sysctl(8).

     * vfs.zfs.l2arc_write_max - Limit the amount of data written to the
       L2ARC per second. This tunable is designed to extend the longevity of
       SSDs by limiting the amount of data written to the device. This value
       can be adjusted at any time with sysctl(8).

     * vfs.zfs.l2arc_write_boost - The value of this tunable is added to
       vfs.zfs.l2arc_write_max and increases the write speed to the SSD until
       the first block is evicted from the L2ARC. This "Turbo Warmup Phase"
       is designed to reduce the performance loss from an empty L2ARC after a
       reboot. This value can be adjusted at any time with sysctl(8).

     * vfs.zfs.scrub_delay - Number of ticks to delay between each I/O during
       a scrub. To ensure that a scrub does not interfere with the normal
       operation of the pool, if any other I/O is happening the scrub will
       delay between each command. This value controls the limit on the total
       IOPS (I/Os Per Second) generated by the scrub. The granularity of the
       setting is determined by the value of kern.hz which defaults to 1000
       ticks per second. This setting may be changed, resulting in a
       different effective IOPS limit. The default value is 4, resulting in a
       limit of: 1000 ticks/sec / 4 = 250 IOPS. Using a value of 20 would
       give a limit of: 1000 ticks/sec / 20 = 50 IOPS. The speed of scrub is
       only limited when there has been recent activity on the pool, as
       determined by vfs.zfs.scan_idle. This value can be adjusted at any
       time with sysctl(8).

     * vfs.zfs.resilver_delay - Number of milliseconds of delay inserted
       between each I/O during a resilver. To ensure that a resilver does not
       interfere with the normal operation of the pool, if any other I/O is
       happening the resilver will delay between each command. This value
       controls the limit of total IOPS (I/Os Per Second) generated by the
       resilver. The granularity of the setting is determined by the value of
       kern.hz which defaults to 1000 ticks per second. This setting may be
       changed, resulting in a different effective IOPS limit. The default
       value is 2, resulting in a limit of: 1000 ticks/sec / 2 = 500 IOPS.
       Returning the pool to an Online state may be more important if another
       device failing could Fault the pool, causing data loss. A value of 0
       will give the resilver operation the same priority as other
       operations, speeding the healing process. The speed of resilver is
       only limited when there has been other recent activity on the pool, as
       determined by vfs.zfs.scan_idle. This value can be adjusted at any
       time with sysctl(8).

     * vfs.zfs.scan_idle - Number of milliseconds since the last operation
       before the pool is considered idle. When the pool is idle the rate
       limiting for scrub and resilver are disabled. This value can be
       adjusted at any time with sysctl(8).

     * vfs.zfs.txg.timeout - Maximum number of seconds between transaction
       groups. The current transaction group will be written to the pool and
       a fresh transaction group started if this amount of time has elapsed
       since the previous transaction group. A transaction group my be
       triggered earlier if enough data is written. The default value is 5
       seconds. A larger value may improve read performance by delaying
       asynchronous writes, but this may cause uneven performance when the
       transaction group is written. This value can be adjusted at any time
       with sysctl(8).

  20.6.2. ZFS on i386

   Some of the features provided by ZFS are memory intensive, and may require
   tuning for maximum efficiency on systems with limited RAM.

    20.6.2.1. Memory

   As a bare minimum, the total system memory should be at least one
   gigabyte. The amount of recommended RAM depends upon the size of the pool
   and which ZFS features are used. A general rule of thumb is 1 GB of RAM
   for every 1 TB of storage. If the deduplication feature is used, a general
   rule of thumb is 5 GB of RAM per TB of storage to be deduplicated. While
   some users successfully use ZFS with less RAM, systems under heavy load
   may panic due to memory exhaustion. Further tuning may be required for
   systems with less than the recommended RAM requirements.

    20.6.2.2. Kernel Configuration

   Due to the address space limitations of the i386(TM) platform, ZFS users
   on the i386(TM) architecture must add this option to a custom kernel
   configuration file, rebuild the kernel, and reboot:

 options        KVA_PAGES=512

   This expands the kernel address space, allowing the vm.kvm_size tunable to
   be pushed beyond the currently imposed limit of 1 GB, or the limit of 2 GB
   for PAE. To find the most suitable value for this option, divide the
   desired address space in megabytes by four. In this example, it is 512 for
   2 GB.

    20.6.2.3. Loader Tunables

   The kmem address space can be increased on all FreeBSD architectures. On a
   test system with 1 GB of physical memory, success was achieved with these
   options added to /boot/loader.conf, and the system restarted:

 vm.kmem_size="330M"
 vm.kmem_size_max="330M"
 vfs.zfs.arc_max="40M"
 vfs.zfs.vdev.cache.size="5M"

   For a more detailed list of recommendations for ZFS-related tuning, see
   https://wiki.freebsd.org/ZFSTuningGuide.

20.7. Additional Resources

     * OpenZFS

     * FreeBSD Wiki - ZFS Tuning

     * Oracle Solaris ZFS Administration Guide

     * Calomel Blog - ZFS Raidz Performance, Capacity and Integrity

20.8. ZFS Features and Terminology

   ZFS is a fundamentally different file system because it is more than just
   a file system. ZFS combines the roles of file system and volume manager,
   enabling additional storage devices to be added to a live system and
   having the new space available on all of the existing file systems in that
   pool immediately. By combining the traditionally separate roles, ZFS is
   able to overcome previous limitations that prevented RAID groups being
   able to grow. Each top level device in a pool is called a vdev, which can
   be a simple disk or a RAID transformation such as a mirror or RAID-Z
   array. ZFS file systems (called datasets) each have access to the combined
   free space of the entire pool. As blocks are allocated from the pool, the
   space available to each file system decreases. This approach avoids the
   common pitfall with extensive partitioning where free space becomes
   fragmented across the partitions.

   +------------------------------------------------------------------------+
   | pool                  | A storage pool is the most basic building      |
   |                       | block of ZFS. A pool is made up of one or more |
   |                       | vdevs, the underlying devices that store the   |
   |                       | data. A pool is then used to create one or     |
   |                       | more file systems (datasets) or block devices  |
   |                       | (volumes). These datasets and volumes share    |
   |                       | the pool of remaining free space. Each pool is |
   |                       | uniquely identified by a name and a GUID. The  |
   |                       | features available are determined by the ZFS   |
   |                       | version number on the pool.                    |
   |-----------------------+------------------------------------------------|
   | vdev Types            | A pool is made up of one or more vdevs, which  |
   |                       | themselves can be a single disk or a group of  |
   |                       | disks, in the case of a RAID transform. When   |
   |                       | multiple vdevs are used, ZFS spreads data      |
   |                       | across the vdevs to increase performance and   |
   |                       | maximize usable space.                         |
   |                       |   * Disk - The most basic type of vdev is a    |
   |                       |     standard block device. This can be an      |
   |                       |     entire disk (such as /dev/ada0 or          |
   |                       |     /dev/da0) or a partition (/dev/ada0p3). On |
   |                       |     FreeBSD, there is no performance penalty   |
   |                       |     for using a partition rather than the      |
   |                       |     entire disk. This differs from             |
   |                       |     recommendations made by the Solaris        |
   |                       |     documentation.                             |
   |                       |                                                |
   |                       |  Caution:                                      |
   |                       |                                                |
   |                       |     Using an entire disk as part of a bootable |
   |                       |     pool is strongly discouraged, as this may  |
   |                       |     render the pool unbootable. Likewise, you  |
   |                       |     should not use an entire disk as part of a |
   |                       |     mirror or RAID-Z vdev. These are because   |
   |                       |     it is impossible to reliably determine the |
   |                       |     size of an unpartitioned disk at boot time |
   |                       |     and because there's no place to put in     |
   |                       |     boot code.                                 |
   |                       |                                                |
   |                       |   * File - In addition to disks, ZFS pools can |
   |                       |     be backed by regular files, this is        |
   |                       |     especially useful for testing and          |
   |                       |     experimentation. Use the full path to the  |
   |                       |     file as the device path in zpool create.   |
   |                       |     All vdevs must be at least 128 MB in size. |
   |                       |                                                |
   |                       |   * Mirror - When creating a mirror, specify   |
   |                       |     the mirror keyword followed by the list of |
   |                       |     member devices for the mirror. A mirror    |
   |                       |     consists of two or more devices, all data  |
   |                       |     will be written to all member devices. A   |
   |                       |     mirror vdev will only hold as much data as |
   |                       |     its smallest member. A mirror vdev can     |
   |                       |     withstand the failure of all but one of    |
   |                       |     its members without losing any data.       |
   |                       |                                                |
   |                       |  Note:                                         |
   |                       |                                                |
   |                       |     A regular single disk vdev can be upgraded |
   |                       |     to a mirror vdev at any time with zpool    |
   |                       |     attach.                                    |
   |                       |                                                |
   |                       |   * RAID-Z - ZFS implements RAID-Z, a          |
   |                       |     variation on standard RAID-5 that offers   |
   |                       |     better distribution of parity and          |
   |                       |     eliminates the "RAID-5 write hole" in      |
   |                       |     which the data and parity information      |
   |                       |     become inconsistent after an unexpected    |
   |                       |     restart. ZFS supports three levels of      |
   |                       |     RAID-Z which provide varying levels of     |
   |                       |     redundancy in exchange for decreasing      |
   |                       |     levels of usable storage. The types are    |
   |                       |     named RAID-Z1 through RAID-Z3 based on the |
   |                       |     number of parity devices in the array and  |
   |                       |     the number of disks which can fail while   |
   |                       |     the pool remains operational.              |
   |                       |                                                |
   |                       |     In a RAID-Z1 configuration with four       |
   |                       |     disks, each 1 TB, usable storage is 3 TB   |
   |                       |     and the pool will still be able to operate |
   |                       |     in degraded mode with one faulted disk. If |
   |                       |     an additional disk goes offline before the |
   |                       |     faulted disk is replaced and resilvered,   |
   |                       |     all data in the pool can be lost.          |
   |                       |                                                |
   |                       |     In a RAID-Z3 configuration with eight      |
   |                       |     disks of 1 TB, the volume will provide     |
   |                       |     5 TB of usable space and still be able to  |
   |                       |     operate with three faulted disks. Sun(TM)  |
   |                       |     recommends no more than nine disks in a    |
   |                       |     single vdev. If the configuration has more |
   |                       |     disks, it is recommended to divide them    |
   |                       |     into separate vdevs and the pool data will |
   |                       |     be striped across them.                    |
   |                       |                                                |
   |                       |     A configuration of two RAID-Z2 vdevs       |
   |                       |     consisting of 8 disks each would create    |
   |                       |     something similar to a RAID-60 array. A    |
   |                       |     RAID-Z group's storage capacity is         |
   |                       |     approximately the size of the smallest     |
   |                       |     disk multiplied by the number of           |
   |                       |     non-parity disks. Four 1 TB disks in       |
   |                       |     RAID-Z1 has an effective size of           |
   |                       |     approximately 3 TB, and an array of eight  |
   |                       |     1 TB disks in RAID-Z3 will yield 5 TB of   |
   |                       |     usable space.                              |
   |                       |                                                |
   |                       |   * Spare - ZFS has a special pseudo-vdev type |
   |                       |     for keeping track of available hot spares. |
   |                       |     Note that installed hot spares are not     |
   |                       |     deployed automatically; they must manually |
   |                       |     be configured to replace the failed device |
   |                       |     using zfs replace.                         |
   |                       |                                                |
   |                       |   * Log - ZFS Log Devices, also known as ZFS   |
   |                       |     Intent Log (ZIL) move the intent log from  |
   |                       |     the regular pool devices to a dedicated    |
   |                       |     device, typically an SSD. Having a         |
   |                       |     dedicated log device can significantly     |
   |                       |     improve the performance of applications    |
   |                       |     with a high volume of synchronous writes,  |
   |                       |     especially databases. Log devices can be   |
   |                       |     mirrored, but RAID-Z is not supported. If  |
   |                       |     multiple log devices are used, writes will |
   |                       |     be load balanced across them.              |
   |                       |                                                |
   |                       |   * Cache - Adding a cache vdev to a pool will |
   |                       |     add the storage of the cache to the L2ARC. |
   |                       |     Cache devices cannot be mirrored. Since a  |
   |                       |     cache device only stores additional copies |
   |                       |     of existing data, there is no risk of data |
   |                       |     loss.                                      |
   |-----------------------+------------------------------------------------|
   | Transaction Group     | Transaction Groups are the way changed blocks  |
   | (TXG)                 | are grouped together and eventually written to |
   |                       | the pool. Transaction groups are the atomic    |
   |                       | unit that ZFS uses to assert consistency. Each |
   |                       | transaction group is assigned a unique 64-bit  |
   |                       | consecutive identifier. There can be up to     |
   |                       | three active transaction groups at a time, one |
   |                       | in each of these three states:                 |
   |                       |   * Open - When a new transaction group is     |
   |                       |     created, it is in the open state, and      |
   |                       |     accepts new writes. There is always a      |
   |                       |     transaction group in the open state,       |
   |                       |     however the transaction group may refuse   |
   |                       |     new writes if it has reached a limit. Once |
   |                       |     the open transaction group has reached a   |
   |                       |     limit, or the vfs.zfs.txg.timeout has been |
   |                       |     reached, the transaction group advances to |
   |                       |     the next state.                            |
   |                       |                                                |
   |                       |   * Quiescing - A short state that allows any  |
   |                       |     pending operations to finish while not     |
   |                       |     blocking the creation of a new open        |
   |                       |     transaction group. Once all of the         |
   |                       |     transactions in the group have completed,  |
   |                       |     the transaction group advances to the      |
   |                       |     final state.                               |
   |                       |                                                |
   |                       |   * Syncing - All of the data in the           |
   |                       |     transaction group is written to stable     |
   |                       |     storage. This process will in turn modify  |
   |                       |     other data, such as metadata and space     |
   |                       |     maps, that will also need to be written to |
   |                       |     stable storage. The process of syncing     |
   |                       |     involves multiple passes. The first, all   |
   |                       |     of the changed data blocks, is the         |
   |                       |     biggest, followed by the metadata, which   |
   |                       |     may take multiple passes to complete.      |
   |                       |     Since allocating space for the data blocks |
   |                       |     generates new metadata, the syncing state  |
   |                       |     cannot finish until a pass completes that  |
   |                       |     does not allocate any additional space.    |
   |                       |     The syncing state is also where synctasks  |
   |                       |     are completed. Synctasks are               |
   |                       |     administrative operations, such as         |
   |                       |     creating or destroying snapshots and       |
   |                       |     datasets, that modify the uberblock are    |
   |                       |     completed. Once the sync state is          |
   |                       |     complete, the transaction group in the     |
   |                       |     quiescing state is advanced to the syncing |
   |                       |     state.                                     |
   |                       |                                                |
   |                       | All administrative functions, such as snapshot |
   |                       | are written as part of the transaction group.  |
   |                       | When a synctask is created, it is added to the |
   |                       | currently open transaction group, and that     |
   |                       | group is advanced as quickly as possible to    |
   |                       | the syncing state to reduce the latency of     |
   |                       | administrative commands.                       |
   |-----------------------+------------------------------------------------|
   | Adaptive Replacement  | ZFS uses an Adaptive Replacement Cache (ARC),  |
   | Cache (ARC)           | rather than a more traditional Least Recently  |
   |                       | Used (LRU) cache. An LRU cache is a simple     |
   |                       | list of items in the cache, sorted by when     |
   |                       | each object was most recently used. New items  |
   |                       | are added to the top of the list. When the     |
   |                       | cache is full, items from the bottom of the    |
   |                       | list are evicted to make room for more active  |
   |                       | objects. An ARC consists of four lists; the    |
   |                       | Most Recently Used (MRU) and Most Frequently   |
   |                       | Used (MFU) objects, plus a ghost list for      |
   |                       | each. These ghost lists track recently evicted |
   |                       | objects to prevent them from being added back  |
   |                       | to the cache. This increases the cache hit     |
   |                       | ratio by avoiding objects that have a history  |
   |                       | of only being used occasionally. Another       |
   |                       | advantage of using both an MRU and MFU is that |
   |                       | scanning an entire file system would normally  |
   |                       | evict all data from an MRU or LRU cache in     |
   |                       | favor of this freshly accessed content. With   |
   |                       | ZFS, there is also an MFU that only tracks the |
   |                       | most frequently used objects, and the cache of |
   |                       | the most commonly accessed blocks remains.     |
   |-----------------------+------------------------------------------------|
   | L2ARC                 | L2ARC is the second level of the ZFS caching   |
   |                       | system. The primary ARC is stored in RAM.      |
   |                       | Since the amount of available RAM is often     |
   |                       | limited, ZFS can also use cache vdevs. Solid   |
   |                       | State Disks (SSDs) are often used as these     |
   |                       | cache devices due to their higher speed and    |
   |                       | lower latency compared to traditional spinning |
   |                       | disks. L2ARC is entirely optional, but having  |
   |                       | one will significantly increase read speeds    |
   |                       | for files that are cached on the SSD instead   |
   |                       | of having to be read from the regular disks.   |
   |                       | L2ARC can also speed up deduplication because  |
   |                       | a DDT that does not fit in RAM but does fit in |
   |                       | the L2ARC will be much faster than a DDT that  |
   |                       | must be read from disk. The rate at which data |
   |                       | is added to the cache devices is limited to    |
   |                       | prevent prematurely wearing out SSDs with too  |
   |                       | many writes. Until the cache is full (the      |
   |                       | first block has been evicted to make room),    |
   |                       | writing to the L2ARC is limited to the sum of  |
   |                       | the write limit and the boost limit, and       |
   |                       | afterwards limited to the write limit. A pair  |
   |                       | of sysctl(8) values control these rate limits. |
   |                       | vfs.zfs.l2arc_write_max controls how many      |
   |                       | bytes are written to the cache per second,     |
   |                       | while vfs.zfs.l2arc_write_boost adds to this   |
   |                       | limit during the "Turbo Warmup Phase" (Write   |
   |                       | Boost).                                        |
   |-----------------------+------------------------------------------------|
   | ZIL                   | ZIL accelerates synchronous transactions by    |
   |                       | using storage devices like SSDs that are       |
   |                       | faster than those used in the main storage     |
   |                       | pool. When an application requests a           |
   |                       | synchronous write (a guarantee that the data   |
   |                       | has been safely stored to disk rather than     |
   |                       | merely cached to be written later), the data   |
   |                       | is written to the faster ZIL storage, then     |
   |                       | later flushed out to the regular disks. This   |
   |                       | greatly reduces latency and improves           |
   |                       | performance. Only synchronous workloads like   |
   |                       | databases will benefit from a ZIL. Regular     |
   |                       | asynchronous writes such as copying files will |
   |                       | not use the ZIL at all.                        |
   |-----------------------+------------------------------------------------|
   | Copy-On-Write         | Unlike a traditional file system, when data is |
   |                       | overwritten on ZFS, the new data is written to |
   |                       | a different block rather than overwriting the  |
   |                       | old data in place. Only when this write is     |
   |                       | complete is the metadata then updated to point |
   |                       | to the new location. In the event of a shorn   |
   |                       | write (a system crash or power loss in the     |
   |                       | middle of writing a file), the entire original |
   |                       | contents of the file are still available and   |
   |                       | the incomplete write is discarded. This also   |
   |                       | means that ZFS does not require a fsck(8)      |
   |                       | after an unexpected shutdown.                  |
   |-----------------------+------------------------------------------------|
   | Dataset               | Dataset is the generic term for a ZFS file     |
   |                       | system, volume, snapshot or clone. Each        |
   |                       | dataset has a unique name in the format        |
   |                       | poolname/path@snapshot. The root of the pool   |
   |                       | is technically a dataset as well. Child        |
   |                       | datasets are named hierarchically like         |
   |                       | directories. For example, mypool/home, the     |
   |                       | home dataset, is a child of mypool and         |
   |                       | inherits properties from it. This can be       |
   |                       | expanded further by creating mypool/home/user. |
   |                       | This grandchild dataset will inherit           |
   |                       | properties from the parent and grandparent.    |
   |                       | Properties on a child can be set to override   |
   |                       | the defaults inherited from the parents and    |
   |                       | grandparents. Administration of datasets and   |
   |                       | their children can be delegated.               |
   |-----------------------+------------------------------------------------|
   | File system           | A ZFS dataset is most often used as a file     |
   |                       | system. Like most other file systems, a ZFS    |
   |                       | file system is mounted somewhere in the        |
   |                       | systems directory hierarchy and contains files |
   |                       | and directories of its own with permissions,   |
   |                       | flags, and other metadata.                     |
   |-----------------------+------------------------------------------------|
   | Volume                | In additional to regular file system datasets, |
   |                       | ZFS can also create volumes, which are block   |
   |                       | devices. Volumes have many of the same         |
   |                       | features, including copy-on-write, snapshots,  |
   |                       | clones, and checksumming. Volumes can be       |
   |                       | useful for running other file system formats   |
   |                       | on top of ZFS, such as UFS virtualization, or  |
   |                       | exporting iSCSI extents.                       |
   |-----------------------+------------------------------------------------|
   | Snapshot              | The copy-on-write (COW) design of ZFS allows   |
   |                       | for nearly instantaneous, consistent snapshots |
   |                       | with arbitrary names. After taking a snapshot  |
   |                       | of a dataset, or a recursive snapshot of a     |
   |                       | parent dataset that will include all child     |
   |                       | datasets, new data is written to new blocks,   |
   |                       | but the old blocks are not reclaimed as free   |
   |                       | space. The snapshot contains the original      |
   |                       | version of the file system, and the live file  |
   |                       | system contains any changes made since the     |
   |                       | snapshot was taken. No additional space is     |
   |                       | used. As new data is written to the live file  |
   |                       | system, new blocks are allocated to store this |
   |                       | data. The apparent size of the snapshot will   |
   |                       | grow as the blocks are no longer used in the   |
   |                       | live file system, but only in the snapshot.    |
   |                       | These snapshots can be mounted read only to    |
   |                       | allow for the recovery of previous versions of |
   |                       | files. It is also possible to rollback a live  |
   |                       | file system to a specific snapshot, undoing    |
   |                       | any changes that took place after the snapshot |
   |                       | was taken. Each block in the pool has a        |
   |                       | reference counter which keeps track of how     |
   |                       | many snapshots, clones, datasets, or volumes   |
   |                       | make use of that block. As files and snapshots |
   |                       | are deleted, the reference count is            |
   |                       | decremented. When a block is no longer         |
   |                       | referenced, it is reclaimed as free space.     |
   |                       | Snapshots can also be marked with a hold. When |
   |                       | a snapshot is held, any attempt to destroy it  |
   |                       | will return an EBUSY error. Each snapshot can  |
   |                       | have multiple holds, each with a unique name.  |
   |                       | The release command removes the hold so the    |
   |                       | snapshot can deleted. Snapshots can be taken   |
   |                       | on volumes, but they can only be cloned or     |
   |                       | rolled back, not mounted independently.        |
   |-----------------------+------------------------------------------------|
   | Clone                 | Snapshots can also be cloned. A clone is a     |
   |                       | writable version of a snapshot, allowing the   |
   |                       | file system to be forked as a new dataset. As  |
   |                       | with a snapshot, a clone initially consumes no |
   |                       | additional space. As new data is written to a  |
   |                       | clone and new blocks are allocated, the        |
   |                       | apparent size of the clone grows. When blocks  |
   |                       | are overwritten in the cloned file system or   |
   |                       | volume, the reference count on the previous    |
   |                       | block is decremented. The snapshot upon which  |
   |                       | a clone is based cannot be deleted because the |
   |                       | clone depends on it. The snapshot is the       |
   |                       | parent, and the clone is the child. Clones can |
   |                       | be promoted, reversing this dependency and     |
   |                       | making the clone the parent and the previous   |
   |                       | parent the child. This operation requires no   |
   |                       | additional space. Since the amount of space    |
   |                       | used by the parent and child is reversed,      |
   |                       | existing quotas and reservations might be      |
   |                       | affected.                                      |
   |-----------------------+------------------------------------------------|
   | Checksum              | Every block that is allocated is also          |
   |                       | checksummed. The checksum algorithm used is a  |
   |                       | per-dataset property, see set. The checksum of |
   |                       | each block is transparently validated as it is |
   |                       | read, allowing ZFS to detect silent            |
   |                       | corruption. If the data that is read does not  |
   |                       | match the expected checksum, ZFS will attempt  |
   |                       | to recover the data from any available         |
   |                       | redundancy, like mirrors or RAID-Z).           |
   |                       | Validation of all checksums can be triggered   |
   |                       | with scrub. Checksum algorithms include:       |
   |                       |   * fletcher2                                  |
   |                       |                                                |
   |                       |   * fletcher4                                  |
   |                       |                                                |
   |                       |   * sha256                                     |
   |                       |                                                |
   |                       | The fletcher algorithms are faster, but sha256 |
   |                       | is a strong cryptographic hash and has a much  |
   |                       | lower chance of collisions at the cost of some |
   |                       | performance. Checksums can be disabled, but it |
   |                       | is not recommended.                            |
   |-----------------------+------------------------------------------------|
   | Compression           | Each dataset has a compression property, which |
   |                       | defaults to off. This property can be set to   |
   |                       | one of a number of compression algorithms.     |
   |                       | This will cause all new data that is written   |
   |                       | to the dataset to be compressed. Beyond a      |
   |                       | reduction in space used, read and write        |
   |                       | throughput often increases because fewer       |
   |                       | blocks are read or written.                    |
   |                       |   * LZ4 - Added in ZFS pool version 5000       |
   |                       |     (feature flags), LZ4 is now the            |
   |                       |     recommended compression algorithm. LZ4     |
   |                       |     compresses approximately 50% faster than   |
   |                       |     LZJB when operating on compressible data,  |
   |                       |     and is over three times faster when        |
   |                       |     operating on uncompressible data. LZ4 also |
   |                       |     decompresses approximately 80% faster than |
   |                       |     LZJB. On modern CPUs, LZ4 can often        |
   |                       |     compress at over 500 MB/s, and decompress  |
   |                       |     at over 1.5 GB/s (per single CPU core).    |
   |                       |                                                |
   |                       |   * LZJB - The default compression algorithm.  |
   |                       |     Created by Jeff Bonwick (one of the        |
   |                       |     original creators of ZFS). LZJB offers     |
   |                       |     good compression with less CPU overhead    |
   |                       |     compared to GZIP. In the future, the       |
   |                       |     default compression algorithm will likely  |
   |                       |     change to LZ4.                             |
   |                       |                                                |
   |                       |   * GZIP - A popular stream compression        |
   |                       |     algorithm available in ZFS. One of the     |
   |                       |     main advantages of using GZIP is its       |
   |                       |     configurable level of compression. When    |
   |                       |     setting the compress property, the         |
   |                       |     administrator can choose the level of      |
   |                       |     compression, ranging from gzip1, the       |
   |                       |     lowest level of compression, to gzip9, the |
   |                       |     highest level of compression. This gives   |
   |                       |     the administrator control over how much    |
   |                       |     CPU time to trade for saved disk space.    |
   |                       |                                                |
   |                       |   * ZLE - Zero Length Encoding is a special    |
   |                       |     compression algorithm that only compresses |
   |                       |     continuous runs of zeros. This compression |
   |                       |     algorithm is only useful when the dataset  |
   |                       |     contains large blocks of zeros.            |
   |-----------------------+------------------------------------------------|
   | Copies                | When set to a value greater than 1, the copies |
   |                       | property instructs ZFS to maintain multiple    |
   |                       | copies of each block in the File System or     |
   |                       | Volume. Setting this property on important     |
   |                       | datasets provides additional redundancy from   |
   |                       | which to recover a block that does not match   |
   |                       | its checksum. In pools without redundancy, the |
   |                       | copies feature is the only form of redundancy. |
   |                       | The copies feature can recover from a single   |
   |                       | bad sector or other forms of minor corruption, |
   |                       | but it does not protect the pool from the loss |
   |                       | of an entire disk.                             |
   |-----------------------+------------------------------------------------|
   | Deduplication         | Checksums make it possible to detect duplicate |
   |                       | blocks of data as they are written. With       |
   |                       | deduplication, the reference count of an       |
   |                       | existing, identical block is increased, saving |
   |                       | storage space. To detect duplicate blocks, a   |
   |                       | deduplication table (DDT) is kept in memory.   |
   |                       | The table contains a list of unique checksums, |
   |                       | the location of those blocks, and a reference  |
   |                       | count. When new data is written, the checksum  |
   |                       | is calculated and compared to the list. If a   |
   |                       | match is found, the existing block is used.    |
   |                       | The SHA256 checksum algorithm is used with     |
   |                       | deduplication to provide a secure              |
   |                       | cryptographic hash. Deduplication is tunable.  |
   |                       | If dedup is on, then a matching checksum is    |
   |                       | assumed to mean that the data is identical. If |
   |                       | dedup is set to verify, then the data in the   |
   |                       | two blocks will be checked byte-for-byte to    |
   |                       | ensure it is actually identical. If the data   |
   |                       | is not identical, the hash collision will be   |
   |                       | noted and the two blocks will be stored        |
   |                       | separately. As DDT must store the hash of each |
   |                       | unique block, it consumes a very large amount  |
   |                       | of memory. A general rule of thumb is 5-6 GB   |
   |                       | of ram per 1 TB of deduplicated data). In      |
   |                       | situations where it is not practical to have   |
   |                       | enough RAM to keep the entire DDT in memory,   |
   |                       | performance will suffer greatly as the DDT     |
   |                       | must be read from disk before each new block   |
   |                       | is written. Deduplication can use L2ARC to     |
   |                       | store the DDT, providing a middle ground       |
   |                       | between fast system memory and slower disks.   |
   |                       | Consider using compression instead, which      |
   |                       | often provides nearly as much space savings    |
   |                       | without the additional memory requirement.     |
   |-----------------------+------------------------------------------------|
   | Scrub                 | Instead of a consistency check like fsck(8),   |
   |                       | ZFS has scrub. scrub reads all data blocks     |
   |                       | stored on the pool and verifies their          |
   |                       | checksums against the known good checksums     |
   |                       | stored in the metadata. A periodic check of    |
   |                       | all the data stored on the pool ensures the    |
   |                       | recovery of any corrupted blocks before they   |
   |                       | are needed. A scrub is not required after an   |
   |                       | unclean shutdown, but is recommended at least  |
   |                       | once every three months. The checksum of each  |
   |                       | block is verified as blocks are read during    |
   |                       | normal use, but a scrub makes certain that     |
   |                       | even infrequently used blocks are checked for  |
   |                       | silent corruption. Data security is improved,  |
   |                       | especially in archival storage situations. The |
   |                       | relative priority of scrub can be adjusted     |
   |                       | with vfs.zfs.scrub_delay to prevent the scrub  |
   |                       | from degrading the performance of other        |
   |                       | workloads on the pool.                         |
   |-----------------------+------------------------------------------------|
   | Dataset Quota         | ZFS provides very fast and accurate dataset,   |
   |                       | user, and group space accounting in addition   |
   |                       | to quotas and space reservations. This gives   |
   |                       | the administrator fine grained control over    |
   |                       | how space is allocated and allows space to be  |
   |                       | reserved for critical file systems.            |
   |                       |                                                |
   |                       | ZFS supports different types of quotas: the    |
   |                       | dataset quota, the reference quota (refquota), |
   |                       | the user quota, and the group quota.           |
   |                       |                                                |
   |                       | Quotas limit the amount of space that a        |
   |                       | dataset and all of its descendants, including  |
   |                       | snapshots of the dataset, child datasets, and  |
   |                       | the snapshots of those datasets, can consume.  |
   |                       |                                                |
   |                       |  Note:                                         |
   |                       |                                                |
   |                       | Quotas cannot be set on volumes, as the        |
   |                       | volsize property acts as an implicit quota.    |
   |-----------------------+------------------------------------------------|
   | Reference Quota       | A reference quota limits the amount of space a |
   |                       | dataset can consume by enforcing a hard limit. |
   |                       | However, this hard limit includes only space   |
   |                       | that the dataset references and does not       |
   |                       | include space used by descendants, such as     |
   |                       | file systems or snapshots.                     |
   |-----------------------+------------------------------------------------|
   | User Quota            | User quotas are useful to limit the amount of  |
   |                       | space that can be used by the specified user.  |
   |-----------------------+------------------------------------------------|
   | Group Quota           | The group quota limits the amount of space     |
   |                       | that a specified group can consume.            |
   |-----------------------+------------------------------------------------|
   | Dataset Reservation   | The reservation property makes it possible to  |
   |                       | guarantee a minimum amount of space for a      |
   |                       | specific dataset and its descendants. If a     |
   |                       | 10 GB reservation is set on storage/home/bob,  |
   |                       | and another dataset tries to use all of the    |
   |                       | free space, at least 10 GB of space is         |
   |                       | reserved for this dataset. If a snapshot is    |
   |                       | taken of storage/home/bob, the space used by   |
   |                       | that snapshot is counted against the           |
   |                       | reservation. The refreservation property works |
   |                       | in a similar way, but it excludes descendants  |
   |                       | like snapshots.                                |
   |                       |                                                |
   |                       | Reservations of any sort are useful in many    |
   |                       | situations, such as planning and testing the   |
   |                       | suitability of disk space allocation in a new  |
   |                       | system, or ensuring that enough space is       |
   |                       | available on file systems for audio logs or    |
   |                       | system recovery procedures and files.          |
   |-----------------------+------------------------------------------------|
   | Reference Reservation | The refreservation property makes it possible  |
   |                       | to guarantee a minimum amount of space for the |
   |                       | use of a specific dataset excluding its        |
   |                       | descendants. This means that if a 10 GB        |
   |                       | reservation is set on storage/home/bob, and    |
   |                       | another dataset tries to use all of the free   |
   |                       | space, at least 10 GB of space is reserved for |
   |                       | this dataset. In contrast to a regular         |
   |                       | reservation, space used by snapshots and       |
   |                       | descendant datasets is not counted against the |
   |                       | reservation. For example, if a snapshot is     |
   |                       | taken of storage/home/bob, enough disk space   |
   |                       | must exist outside of the refreservation       |
   |                       | amount for the operation to succeed.           |
   |                       | Descendants of the main data set are not       |
   |                       | counted in the refreservation amount and so do |
   |                       | not encroach on the space set.                 |
   |-----------------------+------------------------------------------------|
   | Resilver              | When a disk fails and is replaced, the new     |
   |                       | disk must be filled with the data that was     |
   |                       | lost. The process of using the parity          |
   |                       | information distributed across the remaining   |
   |                       | drives to calculate and write the missing data |
   |                       | to the new drive is called resilvering.        |
   |-----------------------+------------------------------------------------|
   | Online                | A pool or vdev in the Online state has all of  |
   |                       | its member devices connected and fully         |
   |                       | operational. Individual devices in the Online  |
   |                       | state are functioning normally.                |
   |-----------------------+------------------------------------------------|
   | Offline               | Individual devices can be put in an Offline    |
   |                       | state by the administrator if there is         |
   |                       | sufficient redundancy to avoid putting the     |
   |                       | pool or vdev into a Faulted state. An          |
   |                       | administrator may choose to offline a disk in  |
   |                       | preparation for replacing it, or to make it    |
   |                       | easier to identify.                            |
   |-----------------------+------------------------------------------------|
   | Degraded              | A pool or vdev in the Degraded state has one   |
   |                       | or more disks that have been disconnected or   |
   |                       | have failed. The pool is still usable, but if  |
   |                       | additional devices fail, the pool could become |
   |                       | unrecoverable. Reconnecting the missing        |
   |                       | devices or replacing the failed disks will     |
   |                       | return the pool to an Online state after the   |
   |                       | reconnected or new device has completed the    |
   |                       | Resilver process.                              |
   |-----------------------+------------------------------------------------|
   | Faulted               | A pool or vdev in the Faulted state is no      |
   |                       | longer operational. The data on it can no      |
   |                       | longer be accessed. A pool or vdev enters the  |
   |                       | Faulted state when the number of missing or    |
   |                       | failed devices exceeds the level of redundancy |
   |                       | in the vdev. If missing devices can be         |
   |                       | reconnected, the pool will return to a Online  |
   |                       | state. If there is insufficient redundancy to  |
   |                       | compensate for the number of failed disks,     |
   |                       | then the contents of the pool are lost and     |
   |                       | must be restored from backups.                 |
   +------------------------------------------------------------------------+

Chapter 21. Other File Systems

   Written by Tom Rhodes.
   Table of Contents

   21.1. Synopsis

   21.2. Linux(R) File Systems

21.1. Synopsis

   File systems are an integral part of any operating system. They allow
   users to upload and store files, provide access to data, and make hard
   drives useful. Different operating systems differ in their native file
   system. Traditionally, the native FreeBSD file system has been the Unix
   File System UFS which has been modernized as UFS2. Since FreeBSD 7.0, the
   Z File System (ZFS) is also available as a native file system. See
   Chapter 20, The Z File System (ZFS) for more information.

   In addition to its native file systems, FreeBSD supports a multitude of
   other file systems so that data from other operating systems can be
   accessed locally, such as data stored on locally attached USB storage
   devices, flash drives, and hard disks. This includes support for the
   Linux(R) Extended File System (EXT).

   There are different levels of FreeBSD support for the various file
   systems. Some require a kernel module to be loaded and others may require
   a toolset to be installed. Some non-native file system support is full
   read-write while others are read-only.

   After reading this chapter, you will know:

     * The difference between native and supported file systems.

     * Which file systems are supported by FreeBSD.

     * How to enable, configure, access, and make use of non-native file
       systems.

   Before reading this chapter, you should:

     * Understand UNIX(R) and FreeBSD basics.

     * Be familiar with the basics of kernel configuration and compilation.

     * Feel comfortable installing software in FreeBSD.

     * Have some familiarity with disks, storage, and device names in
       FreeBSD.

21.2. Linux(R) File Systems

   FreeBSD provides built-in support for several Linux(R) file systems. This
   section demonstrates how to load support for and how to mount the
   supported Linux(R) file systems.

  21.2.1. ext2

   Kernel support for ext2 file systems has been available since FreeBSD 2.2.
   In FreeBSD 8.x and earlier, the code is licensed under the GPL. Since
   FreeBSD 9.0, the code has been rewritten and is now BSD licensed.

   The ext2fs(5) driver allows the FreeBSD kernel to both read and write to
   ext2 file systems.

  Note:

   This driver can also be used to access ext3 and ext4 file systems. The
   ext2fs(5) filesystem has full read and write support for ext4 as of
   FreeBSD 12.0-RELEASE. Additionally, extended attributes and ACLs are also
   supported, while journalling and encryption are not. Starting with
   FreeBSD 12.1-RELEASE, a DTrace provider will be available as well. Prior
   versions of FreeBSD can access ext4 in read and write mode using
   sysutils/fusefs-ext2.

   To access an ext file system, first load the kernel loadable module:

 # kldload ext2fs

   Then, mount the ext volume by specifying its FreeBSD partition name and an
   existing mount point. This example mounts /dev/ad1s1 on /mnt:

 # mount -t ext2fs /dev/ad1s1 /mnt

Chapter 22. Virtualization

   Contributed by Murray Stokely.
   bhyve section by Allan Jude.
   Xen section by Benedict Reuschling.
   Table of Contents

   22.1. Synopsis

   22.2. FreeBSD as a Guest on Parallels for Mac OS(R) X

   22.3. FreeBSD as a Guest on Virtual PC for Windows(R)

   22.4. FreeBSD as a Guest on VMware Fusion for Mac OS(R)

   22.5. FreeBSD as a Guest on VirtualBox(TM)

   22.6. FreeBSD as a Host with VirtualBox(TM)

   22.7. FreeBSD as a Host with bhyve

   22.8. FreeBSD as a Xen(TM)-Host

22.1. Synopsis

   Virtualization software allows multiple operating systems to run
   simultaneously on the same computer. Such software systems for PCs often
   involve a host operating system which runs the virtualization software and
   supports any number of guest operating systems.

   After reading this chapter, you will know:

     * The difference between a host operating system and a guest operating
       system.

     * How to install FreeBSD on an Intel(R)-based Apple(R) Mac(R) computer.

     * How to install FreeBSD on Microsoft(R) Windows(R) with Virtual PC.

     * How to install FreeBSD as a guest in bhyve.

     * How to tune a FreeBSD system for best performance under
       virtualization.

   Before reading this chapter, you should:

     * Understand the basics of UNIX(R) and FreeBSD.

     * Know how to install FreeBSD.

     * Know how to set up a network connection.

     * Know how to install additional third-party software.

22.2. FreeBSD as a Guest on Parallels for Mac OS(R) X

   Parallels Desktop for Mac(R) is a commercial software product available
   for Intel(R) based Apple(R) Mac(R) computers running Mac OS(R) 10.4.6 or
   higher. FreeBSD is a fully supported guest operating system. Once
   Parallels has been installed on Mac OS(R) X, the user must configure a
   virtual machine and then install the desired guest operating system.

  22.2.1. Installing FreeBSD on Parallels/Mac OS(R) X

   The first step in installing FreeBSD on Parallels is to create a new
   virtual machine for installing FreeBSD. Select FreeBSD as the Guest OS
   Type when prompted:

   Choose a reasonable amount of disk and memory depending on the plans for
   this virtual FreeBSD instance. 4GB of disk space and 512MB of RAM work
   well for most uses of FreeBSD under Parallels:

   Select the type of networking and a network interface:

   Save and finish the configuration:

   After the FreeBSD virtual machine has been created, FreeBSD can be
   installed on it. This is best done with an official FreeBSD CD/DVD or with
   an ISO image downloaded from an official FTP site. Copy the appropriate
   ISO image to the local Mac(R) filesystem or insert a CD/DVD in the
   Mac(R)'s CD-ROM drive. Click on the disc icon in the bottom right corner
   of the FreeBSD Parallels window. This will bring up a window that can be
   used to associate the CD-ROM drive in the virtual machine with the ISO
   file on disk or with the real CD-ROM drive.

   Once this association with the CD-ROM source has been made, reboot the
   FreeBSD virtual machine by clicking the reboot icon. Parallels will reboot
   with a special BIOS that first checks if there is a CD-ROM.

   In this case it will find the FreeBSD installation media and begin a
   normal FreeBSD installation. Perform the installation, but do not attempt
   to configure Xorg at this time.

   When the installation is finished, reboot into the newly installed FreeBSD
   virtual machine.

  22.2.2. Configuring FreeBSD on Parallels

   After FreeBSD has been successfully installed on Mac OS(R) X with
   Parallels, there are a number of configuration steps that can be taken to
   optimize the system for virtualized operation.

    1. Set Boot Loader Variables

       The most important step is to reduce the kern.hz tunable to reduce the
       CPU utilization of FreeBSD under the Parallels environment. This is
       accomplished by adding the following line to /boot/loader.conf:

 kern.hz=100

       Without this setting, an idle FreeBSD Parallels guest will use roughly
       15% of the CPU of a single processor iMac(R). After this change the
       usage will be closer to 5%.

    2. Create a New Kernel Configuration File

       All of the SCSI, FireWire, and USB device drivers can be removed from
       a custom kernel configuration file. Parallels provides a virtual
       network adapter used by the ed(4) driver, so all network devices
       except for ed(4) and miibus(4) can be removed from the kernel.

    3. Configure Networking

       The most basic networking setup uses DHCP to connect the virtual
       machine to the same local area network as the host Mac(R). This can be
       accomplished by adding ifconfig_ed0="DHCP" to /etc/rc.conf. More
       advanced networking setups are described in Chapter 32, Advanced
       Networking.

22.3. FreeBSD as a Guest on Virtual PC for Windows(R)

   Virtual PC for Windows(R) is a Microsoft(R) software product available for
   free download. See this website for the system requirements. Once Virtual
   PC has been installed on Microsoft(R) Windows(R), the user can configure a
   virtual machine and then install the desired guest operating system.

  22.3.1. Installing FreeBSD on Virtual PC

   The first step in installing FreeBSD on Virtual PC is to create a new
   virtual machine for installing FreeBSD. Select Create a virtual machine
   when prompted:

   Select Other as the Operating system when prompted:

   Then, choose a reasonable amount of disk and memory depending on the plans
   for this virtual FreeBSD instance. 4GB of disk space and 512MB of RAM work
   well for most uses of FreeBSD under Virtual PC:

   Save and finish the configuration:

   Select the FreeBSD virtual machine and click Settings, then set the type
   of networking and a network interface:

   After the FreeBSD virtual machine has been created, FreeBSD can be
   installed on it. This is best done with an official FreeBSD CD/DVD or with
   an ISO image downloaded from an official FTP site. Copy the appropriate
   ISO image to the local Windows(R) filesystem or insert a CD/DVD in the CD
   drive, then double click on the FreeBSD virtual machine to boot. Then,
   click CD and choose Capture ISO Image... on the Virtual PC window. This
   will bring up a window where the CD-ROM drive in the virtual machine can
   be associated with an ISO file on disk or with the real CD-ROM drive.

   Once this association with the CD-ROM source has been made, reboot the
   FreeBSD virtual machine by clicking Action and Reset. Virtual PC will
   reboot with a special BIOS that first checks for a CD-ROM.

   In this case it will find the FreeBSD installation media and begin a
   normal FreeBSD installation. Continue with the installation, but do not
   attempt to configure Xorg at this time.

   When the installation is finished, remember to eject the CD/DVD or release
   the ISO image. Finally, reboot into the newly installed FreeBSD virtual
   machine.

  22.3.2. Configuring FreeBSD on Virtual PC

   After FreeBSD has been successfully installed on Microsoft(R) Windows(R)
   with Virtual PC, there are a number of configuration steps that can be
   taken to optimize the system for virtualized operation.

    1. Set Boot Loader Variables

       The most important step is to reduce the kern.hz tunable to reduce the
       CPU utilization of FreeBSD under the Virtual PC environment. This is
       accomplished by adding the following line to /boot/loader.conf:

 kern.hz=100

       Without this setting, an idle FreeBSD Virtual PC guest OS will use
       roughly 40% of the CPU of a single processor computer. After this
       change, the usage will be closer to 3%.

    2. Create a New Kernel Configuration File

       All of the SCSI, FireWire, and USB device drivers can be removed from
       a custom kernel configuration file. Virtual PC provides a virtual
       network adapter used by the de(4) driver, so all network devices
       except for de(4) and miibus(4) can be removed from the kernel.

    3. Configure Networking

       The most basic networking setup uses DHCP to connect the virtual
       machine to the same local area network as the Microsoft(R) Windows(R)
       host. This can be accomplished by adding ifconfig_de0="DHCP" to
       /etc/rc.conf. More advanced networking setups are described in
       Chapter 32, Advanced Networking.

22.4. FreeBSD as a Guest on VMware Fusion for Mac OS(R)

   VMware Fusion for Mac(R) is a commercial software product available for
   Intel(R) based Apple(R) Mac(R) computers running Mac OS(R) 10.4.9 or
   higher. FreeBSD is a fully supported guest operating system. Once VMware
   Fusion has been installed on Mac OS(R) X, the user can configure a virtual
   machine and then install the desired guest operating system.

  22.4.1. Installing FreeBSD on VMware Fusion

   The first step is to start VMware Fusion which will load the Virtual
   Machine Library. Click New to create the virtual machine:

   This will load the New Virtual Machine Assistant. Click Continue to
   proceed:

   Select Other as the Operating System and either FreeBSD or FreeBSD 64-bit,
   as the Version when prompted:

   Choose the name of the virtual machine and the directory where it should
   be saved:

   Choose the size of the Virtual Hard Disk for the virtual machine:

   Choose the method to install the virtual machine, either from an ISO image
   or from a CD/DVD:

   Click Finish and the virtual machine will boot:

   Install FreeBSD as usual:

   Once the install is complete, the settings of the virtual machine can be
   modified, such as memory usage:

  Note:

   The System Hardware settings of the virtual machine cannot be modified
   while the virtual machine is running.

   The number of CPUs the virtual machine will have access to:

   The status of the CD-ROM device. Normally the CD/DVD/ISO is disconnected
   from the virtual machine when it is no longer needed.

   The last thing to change is how the virtual machine will connect to the
   network. To allow connections to the virtual machine from other machines
   besides the host, choose Connect directly to the physical network
   (Bridged). Otherwise, Share the host's internet connection (NAT) is
   preferred so that the virtual machine can have access to the Internet, but
   the network cannot access the virtual machine.

   After modifying the settings, boot the newly installed FreeBSD virtual
   machine.

  22.4.2. Configuring FreeBSD on VMware Fusion

   After FreeBSD has been successfully installed on Mac OS(R) X with VMware
   Fusion, there are a number of configuration steps that can be taken to
   optimize the system for virtualized operation.

    1. Set Boot Loader Variables

       The most important step is to reduce the kern.hz tunable to reduce the
       CPU utilization of FreeBSD under the VMware Fusion environment. This
       is accomplished by adding the following line to /boot/loader.conf:

 kern.hz=100

       Without this setting, an idle FreeBSD VMware Fusion guest will use
       roughly 15% of the CPU of a single processor iMac(R). After this
       change, the usage will be closer to 5%.

    2. Create a New Kernel Configuration File

       All of the FireWire, and USB device drivers can be removed from a
       custom kernel configuration file. VMware Fusion provides a virtual
       network adapter used by the em(4) driver, so all network devices
       except for em(4) can be removed from the kernel.

    3. Configure Networking

       The most basic networking setup uses DHCP to connect the virtual
       machine to the same local area network as the host Mac(R). This can be
       accomplished by adding ifconfig_em0="DHCP" to /etc/rc.conf. More
       advanced networking setups are described in Chapter 32, Advanced
       Networking.

22.5. FreeBSD as a Guest on VirtualBox(TM)

   FreeBSD works well as a guest in VirtualBox(TM). The virtualization
   software is available for most common operating systems, including FreeBSD
   itself.

   The VirtualBox(TM) guest additions provide support for:

     * Clipboard sharing.

     * Mouse pointer integration.

     * Host time synchronization.

     * Window scaling.

     * Seamless mode.

  Note:

   These commands are run in the FreeBSD guest.

   First, install the emulators/virtualbox-ose-additions package or port in
   the FreeBSD guest. This will install the port:

 # cd /usr/ports/emulators/virtualbox-ose-additions && make install clean

   Add these lines to /etc/rc.conf:

 vboxguest_enable="YES"
 vboxservice_enable="YES"

   If ntpd(8) or ntpdate(8) is used, disable host time synchronization:

 vboxservice_flags="--disable-timesync"

   Xorg will automatically recognize the vboxvideo driver. It can also be
   manually entered in /etc/X11/xorg.conf:

 Section "Device"
         Identifier "Card0"
         Driver "vboxvideo"
         VendorName "InnoTek Systemberatung GmbH"
         BoardName "VirtualBox Graphics Adapter"
 EndSection

   To use the vboxmouse driver, adjust the mouse section in
   /etc/X11/xorg.conf:

 Section "InputDevice"
         Identifier "Mouse0"
         Driver "vboxmouse"
 EndSection

   HAL users should create the following
   /usr/local/etc/hal/fdi/policy/90-vboxguest.fdi or copy it from
   /usr/local/share/hal/fdi/policy/10osvendor/90-vboxguest.fdi:

 <?xml version="1.0" encoding="utf-8"?>
 <!--
 # Sun VirtualBox
 # Hal driver description for the vboxmouse driver
 # $Id: chapter.xml,v 1.33 2012-03-17 04:53:52 eadler Exp $

         Copyright (C) 2008-2009 Sun Microsystems, Inc.

         This file is part of VirtualBox Open Source Edition (OSE, as
         available from http://www.virtualbox.org. This file is free software;
         you can redistribute it and/or modify it under the terms of the GNU
         General Public License (GPL) as published by the Free Software
         Foundation, in version 2 as it comes in the "COPYING" file of the
         VirtualBox OSE distribution. VirtualBox OSE is distributed in the
         hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.

         Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
         Clara, CA 95054 USA or visit http://www.sun.com if you need
         additional information or have any questions.
 -->
 <deviceinfo version="0.2">
   <device>
     <match key="info.subsystem" string="pci">
       <match key="info.product" string="VirtualBox guest Service">
         <append key="info.capabilities" type="strlist">input</append>
         <append key="info.capabilities" type="strlist">input.mouse</append>
         <merge key="input.x11_driver" type="string">vboxmouse</merge>
         <merge key="input.device" type="string">/dev/vboxguest</merge>
       </match>
     </match>
   </device>
 </deviceinfo>

   Shared folders for file transfers between host and VM are accessible by
   mounting them using mount_vboxvfs. A shared folder can be created on the
   host using the VirtualBox GUI or via vboxmanage. For example, to create a
   shared folder called myshare under /mnt/bsdboxshare for the VM named
   BSDBox, run:

 # vboxmanage sharedfolder add 'BSDBox' --name myshare --hostpath /mnt/bsdboxshare

   Note that the shared folder name must not contain spaces. Mount the shared
   folder from within the guest system like this:

 # mount_vboxvfs -w myshare /mnt

22.6. FreeBSD as a Host with VirtualBox(TM)

   VirtualBox(TM) is an actively developed, complete virtualization package,
   that is available for most operating systems including Windows(R),
   Mac OS(R), Linux(R) and FreeBSD. It is equally capable of running
   Windows(R) or UNIX(R)-like guests. It is released as open source software,
   but with closed-source components available in a separate extension pack.
   These components include support for USB 2.0 devices. More information may
   be found on the "Downloads" page of the VirtualBox(TM) wiki. Currently,
   these extensions are not available for FreeBSD.

  22.6.1. Installing VirtualBox(TM)

   VirtualBox(TM) is available as a FreeBSD package or port in
   emulators/virtualbox-ose. The port can be installed using these commands:

 # cd /usr/ports/emulators/virtualbox-ose
 # make install clean

   One useful option in the port's configuration menu is the GuestAdditions
   suite of programs. These provide a number of useful features in guest
   operating systems, like mouse pointer integration (allowing the mouse to
   be shared between host and guest without the need to press a special
   keyboard shortcut to switch) and faster video rendering, especially in
   Windows(R) guests. The guest additions are available in the Devices menu,
   after the installation of the guest is finished.

   A few configuration changes are needed before VirtualBox(TM) is started
   for the first time. The port installs a kernel module in /boot/modules
   which must be loaded into the running kernel:

 # kldload vboxdrv

   To ensure the module is always loaded after a reboot, add this line to
   /boot/loader.conf:

 vboxdrv_load="YES"

   To use the kernel modules that allow bridged or host-only networking, add
   this line to /etc/rc.conf and reboot the computer:

 vboxnet_enable="YES"

   The vboxusers group is created during installation of VirtualBox(TM). All
   users that need access to VirtualBox(TM) will have to be added as members
   of this group. pw can be used to add new members:

 # pw groupmod vboxusers -m yourusername

   The default permissions for /dev/vboxnetctl are restrictive and need to be
   changed for bridged networking:

 # chown root:vboxusers /dev/vboxnetctl
 # chmod 0660 /dev/vboxnetctl

   To make this permissions change permanent, add these lines to
   /etc/devfs.conf:

 own     vboxnetctl root:vboxusers
 perm    vboxnetctl 0660

   To launch VirtualBox(TM), type from a Xorg session:

 % VirtualBox

   For more information on configuring and using VirtualBox(TM), refer to the
   official website. For FreeBSD-specific information and troubleshooting
   instructions, refer to the relevant page in the FreeBSD wiki.

  22.6.2. VirtualBox(TM) USB Support

   VirtualBox(TM) can be configured to pass USB devices through to the guest
   operating system. The host controller of the OSE version is limited to
   emulating USB 1.1 devices until the extension pack supporting USB 2.0 and
   3.0 devices becomes available on FreeBSD.

   For VirtualBox(TM) to be aware of USB devices attached to the machine, the
   user needs to be a member of the operator group.

 # pw groupmod operator -m yourusername

   Then, add the following to /etc/devfs.rules, or create this file if it
   does not exist yet:

 [system=10]
 add path 'usb/*' mode 0660 group operator

   To load these new rules, add the following to /etc/rc.conf:

 devfs_system_ruleset="system"

   Then, restart devfs:

 # service devfs restart

   Restart the login session and VirtualBox(TM) for these changes to take
   effect, and create USB filters as necessary.

  22.6.3. VirtualBox(TM) Host DVD/CD Access

   Access to the host DVD/CD drives from guests is achieved through the
   sharing of the physical drives. Within VirtualBox(TM), this is set up from
   the Storage window in the Settings of the virtual machine. If needed,
   create an empty IDE CD/DVD device first. Then choose the Host Drive from
   the popup menu for the virtual CD/DVD drive selection. A checkbox labeled
   Passthrough will appear. This allows the virtual machine to use the
   hardware directly. For example, audio CDs or the burner will only function
   if this option is selected.

   HAL needs to run for VirtualBox(TM) DVD/CD functions to work, so enable it
   in /etc/rc.conf and start it if it is not already running:

 hald_enable="YES"

 # service hald start

   In order for users to be able to use VirtualBox(TM) DVD/CD functions, they
   need access to /dev/xpt0, /dev/cdN, and /dev/passN. This is usually
   achieved by making the user a member of operator. Permissions to these
   devices have to be corrected by adding these lines to /etc/devfs.conf:

 perm cd* 0660
 perm xpt0 0660
 perm pass* 0660

 # service devfs restart

22.7. FreeBSD as a Host with bhyve

   The bhyve BSD-licensed hypervisor became part of the base system with
   FreeBSD 10.0-RELEASE. This hypervisor supports a number of guests,
   including FreeBSD, OpenBSD, and many Linux(R) distributions. By default,
   bhyve provides access to serial console and does not emulate a graphical
   console. Virtualization offload features of newer CPUs are used to avoid
   the legacy methods of translating instructions and manually managing
   memory mappings.

   The bhyve design requires a processor that supports Intel(R) Extended Page
   Tables (EPT) or AMD(R) Rapid Virtualization Indexing (RVI) or Nested Page
   Tables (NPT). Hosting Linux(R) guests or FreeBSD guests with more than one
   vCPU requires VMX unrestricted mode support (UG). Most newer processors,
   specifically the Intel(R) Core(TM) i3/i5/i7 and Intel(R) Xeon(TM)
   E3/E5/E7, support these features. UG support was introduced with Intel's
   Westmere micro-architecture. For a complete list of Intel(R) processors
   that support EPT, refer to
   https://ark.intel.com/content/www/us/en/ark/search/featurefilter.html?productType=873&0_ExtendedPageTables=True.
   RVI is found on the third generation and later of the AMD Opteron(TM)
   (Barcelona) processors. The easiest way to tell if a processor supports
   bhyve is to run dmesg or look in /var/run/dmesg.boot for the POPCNT
   processor feature flag on the Features2 line for AMD(R) processors or EPT
   and UG on the VT-x line for Intel(R) processors.

  22.7.1. Preparing the Host

   The first step to creating a virtual machine in bhyve is configuring the
   host system. First, load the bhyve kernel module:

 # kldload vmm

   Then, create a tap interface for the network device in the virtual machine
   to attach to. In order for the network device to participate in the
   network, also create a bridge interface containing the tap interface and
   the physical interface as members. In this example, the physical interface
   is igb0:

 # ifconfig tap0 create
 # sysctl net.link.tap.up_on_open=1
 net.link.tap.up_on_open: 0 -> 1
 # ifconfig bridge0 create
 # ifconfig bridge0 addm igb0 addm tap0
 # ifconfig bridge0 up

  22.7.2. Creating a FreeBSD Guest

   Create a file to use as the virtual disk for the guest machine. Specify
   the size and name of the virtual disk:

 # truncate -s 16G guest.img

   Download an installation image of FreeBSD to install:

 # fetch ftp://ftp.freebsd.org/pub/FreeBSD/releases/ISO-IMAGES/10.3/FreeBSD-10.3-RELEASE-amd64-bootonly.iso
 FreeBSD-10.3-RELEASE-amd64-bootonly.iso       100% of  230 MB  570 kBps 06m17s

   FreeBSD comes with an example script for running a virtual machine in
   bhyve. The script will start the virtual machine and run it in a loop, so
   it will automatically restart if it crashes. The script takes a number of
   options to control the configuration of the machine: -c controls the
   number of virtual CPUs, -m limits the amount of memory available to the
   guest, -t defines which tap device to use, -d indicates which disk image
   to use, -i tells bhyve to boot from the CD image instead of the disk, and
   -I defines which CD image to use. The last parameter is the name of the
   virtual machine, used to track the running machines. This example starts
   the virtual machine in installation mode:

 # sh /usr/share/examples/bhyve/vmrun.sh -c 1 -m 1024M -t tap0 -d guest.img -i -I FreeBSD-10.3-RELEASE-amd64-bootonly.iso guestname

   The virtual machine will boot and start the installer. After installing a
   system in the virtual machine, when the system asks about dropping in to a
   shell at the end of the installation, choose Yes.

   Reboot the virtual machine. While rebooting the virtual machine causes
   bhyve to exit, the vmrun.sh script runs bhyve in a loop and will
   automatically restart it. When this happens, choose the reboot option from
   the boot loader menu in order to escape the loop. Now the guest can be
   started from the virtual disk:

 # sh /usr/share/examples/bhyve/vmrun.sh -c 4 -m 1024M -t tap0 -d guest.img guestname

  22.7.3. Creating a Linux(R) Guest

   In order to boot operating systems other than FreeBSD, the
   sysutils/grub2-bhyve port must be first installed.

   Next, create a file to use as the virtual disk for the guest machine:

 # truncate -s 16G linux.img

   Starting a virtual machine with bhyve is a two step process. First a
   kernel must be loaded, then the guest can be started. The Linux(R) kernel
   is loaded with sysutils/grub2-bhyve. Create a device.map that grub will
   use to map the virtual devices to the files on the host system:

 (hd0) ./linux.img
 (cd0) ./somelinux.iso

   Use sysutils/grub2-bhyve to load the Linux(R) kernel from the ISO image:

 # grub-bhyve -m device.map -r cd0 -M 1024M linuxguest

   This will start grub. If the installation CD contains a grub.cfg, a menu
   will be displayed. If not, the vmlinuz and initrd files must be located
   and loaded manually:

 grub> ls
 (hd0) (cd0) (cd0,msdos1) (host)
 grub> ls (cd0)/isolinux
 boot.cat boot.msg grub.conf initrd.img isolinux.bin isolinux.cfg memtest
 splash.jpg TRANS.TBL vesamenu.c32 vmlinuz
 grub> linux (cd0)/isolinux/vmlinuz
 grub> initrd (cd0)/isolinux/initrd.img
 grub> boot

   Now that the Linux(R) kernel is loaded, the guest can be started:

 # bhyve -A -H -P -s 0:0,hostbridge -s 1:0,lpc -s 2:0,virtio-net,tap0 -s 3:0,virtio-blk,./linux.img \
     -s 4:0,ahci-cd,./somelinux.iso -l com1,stdio -c 4 -m 1024M linuxguest

   The system will boot and start the installer. After installing a system in
   the virtual machine, reboot the virtual machine. This will cause bhyve to
   exit. The instance of the virtual machine needs to be destroyed before it
   can be started again:

 # bhyvectl --destroy --vm=linuxguest

   Now the guest can be started directly from the virtual disk. Load the
   kernel:

 # grub-bhyve -m device.map -r hd0,msdos1 -M 1024M linuxguest
 grub> ls
 (hd0) (hd0,msdos2) (hd0,msdos1) (cd0) (cd0,msdos1) (host)
 (lvm/VolGroup-lv_swap) (lvm/VolGroup-lv_root)
 grub> ls (hd0,msdos1)/
 lost+found/ grub/ efi/ System.map-2.6.32-431.el6.x86_64 config-2.6.32-431.el6.x
 86_64 symvers-2.6.32-431.el6.x86_64.gz vmlinuz-2.6.32-431.el6.x86_64
 initramfs-2.6.32-431.el6.x86_64.img
 grub> linux (hd0,msdos1)/vmlinuz-2.6.32-431.el6.x86_64 root=/dev/mapper/VolGroup-lv_root
 grub> initrd (hd0,msdos1)/initramfs-2.6.32-431.el6.x86_64.img
 grub> boot

   Boot the virtual machine:

 # bhyve -A -H -P -s 0:0,hostbridge -s 1:0,lpc -s 2:0,virtio-net,tap0 \
     -s 3:0,virtio-blk,./linux.img -l com1,stdio -c 4 -m 1024M linuxguest

   Linux(R) will now boot in the virtual machine and eventually present you
   with the login prompt. Login and use the virtual machine. When you are
   finished, reboot the virtual machine to exit bhyve. Destroy the virtual
   machine instance:

 # bhyvectl --destroy --vm=linuxguest

  22.7.4. Booting bhyve Virtual Machines with UEFI Firmware

   In addition to bhyveload and grub-bhyve, the bhyve hypervisor can also
   boot virtual machines using the UEFI userspace firmware. This option may
   support guest operating systems that are not supported by the other
   loaders.

   In order to make use of the UEFI support in bhyve, first obtain the UEFI
   firmware images. This can be done by installing sysutils/bhyve-firmware
   port or package.

   With the firmware in place, add the flags -l bootrom,/path/to/firmware to
   your bhyve command line. The actual bhyve command may look like this:

 # bhyve -AHP -s 0:0,hostbridge -s 1:0,lpc \
 -s 2:0,virtio-net,tap1 -s 3:0,virtio-blk,./disk.img \
 -s 4:0,ahci-cd,./install.iso -c 4 -m 1024M \
 -l bootrom,/usr/local/share/uefi-firmware/BHYVE_UEFI.fd \
 guest

   sysutils/bhyve-firmware also contains a CSM-enabled firmware, to boot
   guests with no UEFI support in legacy BIOS mode:

 # bhyve -AHP -s 0:0,hostbridge -s 1:0,lpc \
 -s 2:0,virtio-net,tap1 -s 3:0,virtio-blk,./disk.img \
 -s 4:0,ahci-cd,./install.iso -c 4 -m 1024M \
 -l bootrom,/usr/local/share/uefi-firmware/BHYVE_UEFI_CSM.fd \
 guest

  22.7.5. Graphical UEFI Framebuffer for bhyve Guests

   The UEFI firmware support is particularly useful with predominantly
   graphical guest operating systems such as Microsoft Windows(R).

   Support for the UEFI-GOP framebuffer may also be enabled with the -s
   29,fbuf,tcp=0.0.0.0:5900 flags. The framebuffer resolution may be
   configured with w=800 and h=600, and bhyve can be instructed to wait for a
   VNC connection before booting the guest by adding wait. The framebuffer
   may be accessed from the host or over the network via the VNC protocol.
   Additionally, -s 30,xhci,tablet can be added to achieve precise mouse
   cursor synchronization with the host.

   The resulting bhyve command would look like this:

 # bhyve -AHP -s 0:0,hostbridge -s 31:0,lpc \
 -s 2:0,virtio-net,tap1 -s 3:0,virtio-blk,./disk.img \
 -s 4:0,ahci-cd,./install.iso -c 4 -m 1024M \
 -s 29,fbuf,tcp=0.0.0.0:5900,w=800,h=600,wait \
 -s 30,xhci,tablet \
 -l bootrom,/usr/local/share/uefi-firmware/BHYVE_UEFI.fd \
 guest

   Note, in BIOS emulation mode, the framebuffer will cease receiving updates
   once control is passed from firmware to guest operating system.

  22.7.6. Using ZFS with bhyve Guests

   If ZFS is available on the host machine, using ZFS volumes instead of disk
   image files can provide significant performance benefits for the guest
   VMs. A ZFS volume can be created by:

 # zfs create -V16G -o volmode=dev zroot/linuxdisk0

   When starting the VM, specify the ZFS volume as the disk drive:

 # bhyve -A -H -P -s 0:0,hostbridge -s 1:0,lpc -s 2:0,virtio-net,tap0 -s3:0,virtio-blk,/dev/zvol/zroot/linuxdisk0 \
     -l com1,stdio -c 4 -m 1024M linuxguest

  22.7.7. Virtual Machine Consoles

   It is advantageous to wrap the bhyve console in a session management tool
   such as sysutils/tmux or sysutils/screen in order to detach and reattach
   to the console. It is also possible to have the console of bhyve be a null
   modem device that can be accessed with cu. To do this, load the nmdm
   kernel module and replace -l com1,stdio with -l com1,/dev/nmdm0A. The
   /dev/nmdm devices are created automatically as needed, where each is a
   pair, corresponding to the two ends of the null modem cable (/dev/nmdm0A
   and /dev/nmdm0B). See nmdm(4) for more information.

 # kldload nmdm
 # bhyve -A -H -P -s 0:0,hostbridge -s 1:0,lpc -s 2:0,virtio-net,tap0 -s 3:0,virtio-blk,./linux.img \
     -l com1,/dev/nmdm0A -c 4 -m 1024M linuxguest
 # cu -l /dev/nmdm0B
 Connected

 Ubuntu 13.10 handbook ttyS0

 handbook login:

  22.7.8. Managing Virtual Machines

   A device node is created in /dev/vmm for each virtual machine. This allows
   the administrator to easily see a list of the running virtual machines:

 # ls -al /dev/vmm
 total 1
 dr-xr-xr-x   2 root  wheel    512 Mar 17 12:19 ./
 dr-xr-xr-x  14 root  wheel    512 Mar 17 06:38 ../
 crw-------   1 root  wheel  0x1a2 Mar 17 12:20 guestname
 crw-------   1 root  wheel  0x19f Mar 17 12:19 linuxguest
 crw-------   1 root  wheel  0x1a1 Mar 17 12:19 otherguest

   A specified virtual machine can be destroyed using bhyvectl:

 # bhyvectl --destroy --vm=guestname

  22.7.9. Persistent Configuration

   In order to configure the system to start bhyve guests at boot time, the
   following configurations must be made in the specified files:

    1. /etc/sysctl.conf

 net.link.tap.up_on_open=1

    2. /etc/rc.conf

 cloned_interfaces="bridge0 tap0"
 ifconfig_bridge0="addm igb0 addm tap0"
 kld_list="nmdm vmm"

22.8. FreeBSD as a Xen(TM)-Host

   Xen is a GPLv2-licensed type 1 hypervisor for Intel(R) and ARM(R)
   architectures. FreeBSD has included i386(TM) and AMD(R) 64-Bit DomU and
   Amazon EC2 unprivileged domain (virtual machine) support since FreeBSD 8.0
   and includes Dom0 control domain (host) support in FreeBSD 11.0. Support
   for para-virtualized (PV) domains has been removed from FreeBSD 11 in
   favor of hardware virtualized (HVM) domains, which provides better
   performance.

   Xen(TM) is a bare-metal hypervisor, which means that it is the first
   program loaded after the BIOS. A special privileged guest called the
   Domain-0 (Dom0 for short) is then started. The Dom0 uses its special
   privileges to directly access the underlying physical hardware, making it
   a high-performance solution. It is able to access the disk controllers and
   network adapters directly. The Xen(TM) management tools to manage and
   control the Xen(TM) hypervisor are also used by the Dom0 to create, list,
   and destroy VMs. Dom0 provides virtual disks and networking for
   unprivileged domains, often called DomU. Xen(TM) Dom0 can be compared to
   the service console of other hypervisor solutions, while the DomU is where
   individual guest VMs are run.

   Xen(TM) can migrate VMs between different Xen(TM) servers. When the two
   xen hosts share the same underlying storage, the migration can be done
   without having to shut the VM down first. Instead, the migration is
   performed live while the DomU is running and there is no need to restart
   it or plan a downtime. This is useful in maintenance scenarios or upgrade
   windows to ensure that the services provided by the DomU are still
   provided. Many more features of Xen(TM) are listed on the Xen Wiki
   Overview page. Note that not all features are supported on FreeBSD yet.

  22.8.1. Hardware Requirements for Xen(TM) Dom0

   To run the Xen(TM) hypervisor on a host, certain hardware functionality is
   required. Hardware virtualized domains require Extended Page Table (EPT)
   and Input/Output Memory Management Unit (IOMMU) support in the host
   processor.

  Note:

   In order to run a FreeBSD Xen(TM) Dom0 the box must be booted using legacy
   boot (BIOS).

  22.8.2. Xen(TM) Dom0 Control Domain Setup

   Users of FreeBSD 11 should install the emulators/xen-kernel47 and
   sysutils/xen-tools47 packages that are based on Xen version 4.7. Systems
   running on FreeBSD-12.0 or newer can use Xen 4.11 provided by
   emulators/xen-kernel411 and sysutils/xen-tools411, respectively.

   Configuration files must be edited to prepare the host for the Dom0
   integration after the Xen packages are installed. An entry to
   /etc/sysctl.conf disables the limit on how many pages of memory are
   allowed to be wired. Otherwise, DomU VMs with higher memory requirements
   will not run.

 # echo 'vm.max_wired=-1' >> /etc/sysctl.conf

   Another memory-related setting involves changing /etc/login.conf, setting
   the memorylocked option to unlimited. Otherwise, creating DomU domains may
   fail with Cannot allocate memory errors. After making the change to
   /etc/login.conf, run cap_mkdb to update the capability database. See
   Section 14.13, "Resource Limits" for details.

 # sed -i '' -e 's/memorylocked=64K/memorylocked=unlimited/' /etc/login.conf
 # cap_mkdb /etc/login.conf

   Add an entry for the Xen(TM) console to /etc/ttys:

 # echo 'xc0     "/usr/libexec/getty Pc"         xterm   onifconsole  secure' >> /etc/ttys

   Selecting a Xen(TM) kernel in /boot/loader.conf activates the Dom0.
   Xen(TM) also requires resources like CPU and memory from the host machine
   for itself and other DomU domains. How much CPU and memory depends on the
   individual requirements and hardware capabilities. In this example, 8 GB
   of memory and 4 virtual CPUs are made available for the Dom0. The serial
   console is also activated and logging options are defined.

   The following command is used for Xen 4.7 packages:

 # sysrc -f /boot/loader.conf hw.pci.mcfg=0
 # sysrc -f /boot/loader.conf if_tap_load="YES"
 # sysrc -f /boot/loader.conf xen_kernel="/boot/xen"
 # sysrc -f /boot/loader.conf xen_cmdline="dom0_mem=8192M dom0_max_vcpus=4 dom0pvh=1 console=com1,vga com1=115200,8n1 guest_loglvl=all loglvl=all"

   For Xen versions 4.11 and higher, the following command should be used
   instead:

 # sysrc -f /boot/loader.conf if_tap_load="YES"
 # sysrc -f /boot/loader.conf xen_kernel="/boot/xen"
 # sysrc -f /boot/loader.conf xen_cmdline="dom0_mem=8192M dom0_max_vcpus=4 dom0=pvh console=com1,vga com1=115200,8n1 guest_loglvl=all loglvl=all"

  Tip:

   Log files that Xen(TM) creates for the DomU VMs are stored in
   /var/log/xen. Please be sure to check the contents of that directory if
   experiencing issues.

   Activate the xencommons service during system startup:

 # sysrc xencommons_enable=yes

   These settings are enough to start a Dom0-enabled system. However, it
   lacks network functionality for the DomU machines. To fix that, define a
   bridged interface with the main NIC of the system which the DomU VMs can
   use to connect to the network. Replace em0 with the host network interface
   name.

 # sysrc cloned_interfaces="bridge0"
 # sysrc ifconfig_bridge0="addm em0 SYNCDHCP"
 # sysrc ifconfig_em0="up"

   Restart the host to load the Xen(TM) kernel and start the Dom0.

 # reboot

   After successfully booting the Xen(TM) kernel and logging into the system
   again, the Xen(TM) management tool xl is used to show information about
   the domains.

 # xl list
 Name                                        ID   Mem VCPUs      State   Time(s)
 Domain-0                                     0  8192     4     r-----     962.0

   The output confirms that the Dom0 (called Domain-0) has the ID 0 and is
   running. It also has the memory and virtual CPUs that were defined in
   /boot/loader.conf earlier. More information can be found in the Xen(TM)
   Documentation. DomU guest VMs can now be created.

  22.8.3. Xen(TM) DomU Guest VM Configuration

   Unprivileged domains consist of a configuration file and virtual or
   physical hard disks. Virtual disk storage for the DomU can be files
   created by truncate(1) or ZFS volumes as described in Section 20.4.2,
   "Creating and Destroying Volumes". In this example, a 20 GB volume is
   used. A VM is created with the ZFS volume, a FreeBSD ISO image, 1 GB of
   RAM and two virtual CPUs. The ISO installation file is retrieved with
   fetch(1) and saved locally in a file called freebsd.iso.

 # fetch ftp://ftp.freebsd.org/pub/FreeBSD/releases/ISO-IMAGES/12.0/FreeBSD-12.0-RELEASE-amd64-bootonly.iso -o freebsd.iso

   A ZFS volume of 20 GB called xendisk0 is created to serve as the disk
   space for the VM.

 # zfs create -V20G -o volmode=dev zroot/xendisk0

   The new DomU guest VM is defined in a file. Some specific definitions like
   name, keymap, and VNC connection details are also defined. The following
   freebsd.cfg contains a minimum DomU configuration for this example:

 # cat freebsd.cfg
 builder = "hvm" 1
 name = "freebsd" 2
 memory = 1024 3
 vcpus = 2 4
 vif = [ 'mac=00:16:3E:74:34:32,bridge=bridge0' ] 5
 disk = [
 '/dev/zvol/tank/xendisk0,raw,hda,rw', 6
 '/root/freebsd.iso,raw,hdc:cdrom,r' 7
   ]
 vnc = 1 8
 vnclisten = "0.0.0.0"
 serial = "pty"
 usbdevice = "tablet"

   These lines are explained in more detail:

   1 This defines what kind of virtualization to use. hvm refers to           
     hardware-assisted virtualization or hardware virtual machine. Guest      
     operating systems can run unmodified on CPUs with virtualization         
     extensions, providing nearly the same performance as running on physical 
     hardware. generic is the default value and creates a PV domain.          
   2 Name of this virtual machine to distinguish it from others running on    
     the same Dom0. Required.                                                 
   3 Quantity of RAM in megabytes to make available to the VM. This amount is 
     subtracted from the hypervisor's total available memory, not the memory  
     of the Dom0.                                                             
   4 Number of virtual CPUs available to the guest VM. For best performance,  
     do not create guests with more virtual CPUs than the number of physical  
     CPUs on the host.                                                        
   5 Virtual network adapter. This is the bridge connected to the network     
     interface of the host. The mac parameter is the MAC address set on the   
     virtual network interface. This parameter is optional, if no MAC is      
     provided Xen(TM) will generate a random one.                             
   6 Full path to the disk, file, or ZFS volume of the disk storage for this  
     VM. Options and multiple disk definitions are separated by commas.       
   7 Defines the Boot medium from which the initial operating system is       
     installed. In this example, it is the ISO imaged downloaded earlier.     
     Consult the Xen(TM) documentation for other kinds of devices and options 
     to set.                                                                  
   8 Options controlling VNC connectivity to the serial console of the DomU.  
     In order, these are: active VNC support, define IP address on which to   
     listen, device node for the serial console, and the input method for     
     precise positioning of the mouse and other input methods. keymap defines 
     which keymap to use, and is english by default.                          

   After the file has been created with all the necessary options, the DomU
   is created by passing it to xl create as a parameter.

 # xl create freebsd.cfg

  Note:

   Each time the Dom0 is restarted, the configuration file must be passed to
   xl create again to re-create the DomU. By default, only the Dom0 is
   created after a reboot, not the individual VMs. The VMs can continue where
   they left off as they stored the operating system on the virtual disk. The
   virtual machine configuration can change over time (for example, when
   adding more memory). The virtual machine configuration files must be
   properly backed up and kept available to be able to re-create the guest VM
   when needed.

   The output of xl list confirms that the DomU has been created.

 # xl list
 Name                                        ID   Mem VCPUs      State   Time(s)
 Domain-0                                     0  8192     4     r-----  1653.4
 freebsd                                      1  1024     1     -b----   663.9

   To begin the installation of the base operating system, start the VNC
   client, directing it to the main network address of the host or to the IP
   address defined on the vnclisten line of freebsd.cfg. After the operating
   system has been installed, shut down the DomU and disconnect the VNC
   viewer. Edit freebsd.cfg, removing the line with the cdrom definition or
   commenting it out by inserting a # character at the beginning of the line.
   To load this new configuration, it is necessary to remove the old DomU
   with xl destroy, passing either the name or the id as the parameter.
   Afterwards, recreate it using the modified freebsd.cfg.

 # xl destroy freebsd
 # xl create freebsd.cfg

   The machine can then be accessed again using the VNC viewer. This time, it
   will boot from the virtual disk where the operating system has been
   installed and can be used as a virtual machine.

  22.8.4. Troubleshooting

   This section contains basic information in order to help troubleshoot
   issues found when using FreeBSD as a Xen(TM) host or guest.

    22.8.4.1. Host Boot Troubleshooting

   Please note that the following troubleshooting tips are intended for
   Xen(TM) 4.11 or newer. If you are still using Xen(TM) 4.7 and having
   issues consider migrating to a newer version of Xen(TM).

   In order to troubleshoot host boot issues you will likely need a serial
   cable, or a debug USB cable. Verbose Xen(TM) boot output can be obtained
   by adding options to the xen_cmdline option found in loader.conf. A couple
   of relevant debug options are:

     * iommu=debug: can be used to print additional diagnostic information
       about the iommu.

     * dom0=verbose: can be used to print additional diagnostic information
       about the dom0 build process.

     * sync_console: flag to force synchronous console output. Useful for
       debugging to avoid losing messages due to rate limiting. Never use
       this option in production environments since it can allow malicious
       guests to perform DoS attacks against Xen(TM) using the console.

   FreeBSD should also be booted in verbose mode in order to identify any
   issues. To activate verbose booting, run this command:

 # sysrc -f /boot/loader.conf boot_verbose="YES"

   If none of these options help solving the problem, please send the serial
   boot log to <freebsd-xen@FreeBSD.org> and <xen-devel@lists.xenproject.org>
   for further analysis.

    22.8.4.2. Guest Creation Troubleshooting

   Issues can also arise when creating guests, the following attempts to
   provide some help for those trying to diagnose guest creation issues.

   The most common cause of guest creation failures is the xl command
   spitting some error and exiting with a return code different than 0. If
   the error provided is not enough to help identify the issue, more verbose
   output can also be obtained from xl by using the v option repeatedly.

 # xl -vvv create freebsd.cfg
 Parsing config from freebsd.cfg
 libxl: debug: libxl_create.c:1693:do_domain_create: Domain 0:ao 0x800d750a0: create: how=0x0 callback=0x0 poller=0x800d6f0f0
 libxl: debug: libxl_device.c:397:libxl__device_disk_set_backend: Disk vdev=xvda spec.backend=unknown
 libxl: debug: libxl_device.c:432:libxl__device_disk_set_backend: Disk vdev=xvda, using backend phy
 libxl: debug: libxl_create.c:1018:initiate_domain_create: Domain 1:running bootloader
 libxl: debug: libxl_bootloader.c:328:libxl__bootloader_run: Domain 1:not a PV/PVH domain, skipping bootloader
 libxl: debug: libxl_event.c:689:libxl__ev_xswatch_deregister: watch w=0x800d96b98: deregister unregistered
 domainbuilder: detail: xc_dom_allocate: cmdline="", features=""
 domainbuilder: detail: xc_dom_kernel_file: filename="/usr/local/lib/xen/boot/hvmloader"
 domainbuilder: detail: xc_dom_malloc_filemap    : 326 kB
 libxl: debug: libxl_dom.c:988:libxl__load_hvm_firmware_module: Loading BIOS: /usr/local/share/seabios/bios.bin
 ...

   If the verbose output does not help diagnose the issue there are also QEMU
   and Xen(TM) toolstack logs in /var/log/xen. Note that the name of the
   domain is appended to the log name, so if the domain is named freebsd you
   should find a /var/log/xen/xl-freebsd.log and likely a
   /var/log/xen/qemu-dm-freebsd.log. Both log files can contain useful
   information for debugging. If none of this helps solve the issue, please
   send the description of the issue you are facing and as much information
   as possible to <freebsd-xen@FreeBSD.org> and
   <xen-devel@lists.xenproject.org> in order to get help.

Chapter 23. Localization - i18n/L10n Usage and Setup

   Contributed by Andrey Chernov.
   Rewritten by Michael C. Wu.
   Table of Contents

   23.1. Synopsis

   23.2. Using Localization

   23.3. Finding i18n Applications

   23.4. Locale Configuration for Specific Languages

23.1. Synopsis

   FreeBSD is a distributed project with users and contributors located all
   over the world. As such, FreeBSD supports localization into many
   languages, allowing users to view, input, or process data in non-English
   languages. One can choose from most of the major languages, including, but
   not limited to: Chinese, German, Japanese, Korean, French, Russian, and
   Vietnamese.

   The term internationalization has been shortened to i18n, which represents
   the number of letters between the first and the last letters of
   internationalization. L10n uses the same naming scheme, but from
   localization. The i18n/L10n methods, protocols, and applications allow
   users to use languages of their choice.

   This chapter discusses the internationalization and localization features
   of FreeBSD. After reading this chapter, you will know:

     * How locale names are constructed.

     * How to set the locale for a login shell.

     * How to configure the console for non-English languages.

     * How to configure Xorg for different languages.

     * How to find i18n-compliant applications.

     * Where to find more information for configuring specific languages.

   Before reading this chapter, you should:

     * Know how to install additional third-party applications.

23.2. Using Localization

   Localization settings are based on three components: the language code,
   country code, and encoding. Locale names are constructed from these parts
   as follows:

 LanguageCode_CountryCode.Encoding

   The LanguageCode and CountryCode are used to determine the country and the
   specific language variation. Table 23.1, "Common Language and Country
   Codes" provides some examples of LanguageCode_CountryCode:

   Table 23.1. Common Language and Country Codes

        LanguageCode_Country Code                    Description              
   en_US                                English, United States                
   ru_RU                                Russian, Russia                       
   zh_TW                                Traditional Chinese, Taiwan           

   A complete listing of available locales can be found by typing:

 % locale -a | more

   To determine the current locale setting:

 % locale

   Language specific character sets, such as ISO8859-1, ISO8859-15, KOI8-R,
   and CP437, are described in multibyte(3). The active list of character
   sets can be found at the IANA Registry.

   Some languages, such as Chinese or Japanese, cannot be represented using
   ASCII characters and require an extended language encoding using either
   wide or multibyte characters. Examples of wide or multibyte encodings
   include EUC and Big5. Older applications may mistake these encodings for
   control characters while newer applications usually recognize these
   characters. Depending on the implementation, users may be required to
   compile an application with wide or multibyte character support, or to
   configure it correctly.

  Note:

   FreeBSD uses Xorg-compatible locale encodings.

   The rest of this section describes the various methods for configuring the
   locale on a FreeBSD system. The next section will discuss the
   considerations for finding and compiling applications with i18n support.

  23.2.1. Setting Locale for Login Shell

   Locale settings are configured either in a user's ~/.login_conf or in the
   startup file of the user's shell: ~/.profile, ~/.bashrc, or ~/.cshrc.

   Two environment variables should be set:

     * LANG, which sets the locale

     * MM_CHARSET, which sets the MIME character set used by applications

   In addition to the user's shell configuration, these variables should also
   be set for specific application configuration and Xorg configuration.

   Two methods are available for making the needed variable assignments: the
   login class method, which is the recommended method, and the startup file
   method. The next two sections demonstrate how to use both methods.

    23.2.1.1. Login Classes Method

   This first method is the recommended method as it assigns the required
   environment variables for locale name and MIME character sets for every
   possible shell. This setup can either be performed by each user or it can
   be configured for all users by the superuser.

   This minimal example sets both variables for Latin-1 encoding in the
   .login_conf of an individual user's home directory:

 me:\
         :charset=ISO-8859-1:\
         :lang=de_DE.ISO8859-1:

   Here is an example of a user's ~/.login_conf that sets the variables for
   Traditional Chinese in BIG-5 encoding. More variables are needed because
   some applications do not correctly respect locale variables for Chinese,
   Japanese, and Korean:

 #Users who do not wish to use monetary units or time formats
 #of Taiwan can manually change each variable
 me:\
         :lang=zh_TW.Big5:\
         :setenv=LC_ALL=zh_TW.Big5,LC_COLLATE=zh_TW.Big5,LC_CTYPE=zh_TW.Big5,LC_MESSAGES=zh_TW.Big5,LC_MONETARY=zh_TW.Big5,LC_NUMERIC=zh_TW.Big5,LC_TIME=zh_TW.Big5:\
         :charset=big5:\
         :xmodifiers="@im=gcin": #Set gcin as the XIM Input Server

   Alternately, the superuser can configure all users of the system for
   localization. The following variables in /etc/login.conf are used to set
   the locale and MIME character set:

 language_name|Account Type Description:\
         :charset=MIME_charset:\
         :lang=locale_name:\
         :tc=default:

   So, the previous Latin-1 example would look like this:

 german|German Users Accounts:\
         :charset=ISO-8859-1:\
         :lang=de_DE.ISO8859-1:\
         :tc=default:

   See login.conf(5) for more details about these variables. Note that it
   already contains pre-defined russian class.

   Whenever /etc/login.conf is edited, remember to execute the following
   command to update the capability database:

 # cap_mkdb /etc/login.conf

  Note:

   For an end user, the cap_mkdb command will need to be run on their
   ~/.login_conf for any changes to take effect.

      23.2.1.1.1. Utilities Which Change Login Classes

   In addition to manually editing /etc/login.conf, several utilities are
   available for setting the locale for newly created users.

   When using vipw to add new users, specify the language to set the locale:

 user:password:1111:11:language:0:0:User Name:/home/user:/bin/sh

   When using adduser to add new users, the default language can be
   pre-configured for all new users or specified for an individual user.

   If all new users use the same language, set defaultclass=language in
   /etc/adduser.conf.

   To override this setting when creating a user, either input the required
   locale at this prompt:

 Enter login class: default []:

   or specify the locale to set when invoking adduser:

 # adduser -class language

   If pw is used to add new users, specify the locale as follows:

 # pw useradd user_name -L language

   To change the login class of an existing user, chpass can be used. Invoke
   it as superuser and provide the username to edit as the argument.

 # chpass user_name

    23.2.1.2. Shell Startup File Method

   This second method is not recommended as each shell that is used requires
   manual configuration, where each shell has a different configuration file
   and differing syntax. As an example, to set the German language for the sh
   shell, these lines could be added to ~/.profile to set the shell for that
   user only. These lines could also be added to /etc/profile or
   /usr/share/skel/dot.profile to set that shell for all users:

 LANG=de_DE.ISO8859-1; export LANG
 MM_CHARSET=ISO-8859-1; export MM_CHARSET

   However, the name of the configuration file and the syntax used differs
   for the csh shell. These are the equivalent settings for ~/.csh.login,
   /etc/csh.login, or /usr/share/skel/dot.login:

 setenv LANG de_DE.ISO8859-1
 setenv MM_CHARSET ISO-8859-1

   To complicate matters, the syntax needed to configure Xorg in ~/.xinitrc
   also depends upon the shell. The first example is for the sh shell and the
   second is for the csh shell:

 LANG=de_DE.ISO8859-1; export LANG

 setenv LANG de_DE.ISO8859-1

  23.2.2. Console Setup

   Several localized fonts are available for the console. To see a listing of
   available fonts, type ls /usr/share/syscons/fonts. To configure the
   console font, specify the font_name, without the .fnt suffix, in
   /etc/rc.conf:

 font8x16=font_name
 font8x14=font_name
 font8x8=font_name

   The keymap and screenmap can be set by adding the following to
   /etc/rc.conf:

 scrnmap=screenmap_name
 keymap=keymap_name
 keychange="fkey_number sequence"

   To see the list of available screenmaps, type ls
   /usr/share/syscons/scrnmaps. Do not include the .scm suffix when
   specifying screenmap_name. A screenmap with a corresponding mapped font is
   usually needed as a workaround for expanding bit 8 to bit 9 on a VGA
   adapter's font character matrix so that letters are moved out of the
   pseudographics area if the screen font uses a bit 8 column.

   To see the list of available keymaps, type ls /usr/share/syscons/keymaps.
   When specifying the keymap_name, do not include the .kbd suffix. To test
   keymaps without rebooting, use kbdmap(1).

   The keychange entry is usually needed to program function keys to match
   the selected terminal type because function key sequences cannot be
   defined in the keymap.

   Next, set the correct console terminal type in /etc/ttys for all virtual
   terminal entries. Table 23.2, "Defined Terminal Types for Character Sets"
   summarizes the available terminal types.:

   Table 23.2. Defined Terminal Types for Character Sets

                 Character Set                         Terminal Type          
   ISO8859-1 or ISO8859-15                    cons25l1                        
   ISO8859-2                                  cons25l2                        
   ISO8859-7                                  cons25l7                        
   KOI8-R                                     cons25r                         
   KOI8-U                                     cons25u                         
   CP437 (VGA default)                        cons25                          
   US-ASCII                                   cons25w                         

   For languages with wide or multibyte characters, install a console for
   that language from the FreeBSD Ports Collection. The available ports are
   summarized in Table 23.3, "Available Console from Ports Collection". Once
   installed, refer to the port's pkg-message or man pages for configuration
   and usage instructions.

   Table 23.3. Available Console from Ports Collection

                   Language                           Port Location           
   Traditional Chinese (BIG-5)               chinese/big5con                  
   Chinese/Japanese/Korean                   chinese/cce                      
   Chinese/Japanese/Korean                   chinese/zhcon                    
   Japanese                                  chinese/kon2                     
   Japanese                                  japanese/kon2-14dot              
   Japanese                                  japanese/kon2-16dot              

   If moused is enabled in /etc/rc.conf, additional configuration may be
   required. By default, the mouse cursor of the syscons(4) driver occupies
   the 0xd0-0xd3 range in the character set. If the language uses this range,
   move the cursor's range by adding the following line to /etc/rc.conf:

 mousechar_start=3

  23.2.3. Xorg Setup

   Chapter 5, The X Window System describes how to install and configure
   Xorg. When configuring Xorg for localization, additional fonts and input
   methods are available from the FreeBSD Ports Collection. Application
   specific i18n settings such as fonts and menus can be tuned in
   ~/.Xresources and should allow users to view their selected language in
   graphical application menus.

   The X Input Method (XIM) protocol is an Xorg standard for inputting
   non-English characters. Table 23.4, "Available Input Methods" summarizes
   the input method applications which are available in the FreeBSD Ports
   Collection. Additional Fcitx and Uim applications are also available.

   Table 23.4. Available Input Methods

           Language                            Input Method                   
   Chinese                   chinese/gcin                                     
   Chinese                   chinese/ibus-chewing                             
   Chinese                   chinese/ibus-pinyin                              
   Chinese                   chinese/oxim                                     
   Chinese                   chinese/scim-fcitx                               
   Chinese                   chinese/scim-pinyin                              
   Chinese                   chinese/scim-tables                              
   Japanese                  japanese/ibus-anthy                              
   Japanese                  japanese/ibus-mozc                               
   Japanese                  japanese/ibus-skk                                
   Japanese                  japanese/im-ja                                   
   Japanese                  japanese/kinput2                                 
   Japanese                  japanese/scim-anthy                              
   Japanese                  japanese/scim-canna                              
   Japanese                  japanese/scim-honoka                             
   Japanese                  japanese/scim-honoka-plugin-romkan               
   Japanese                  japanese/scim-honoka-plugin-wnn                  
   Japanese                  japanese/scim-prime                              
   Japanese                  japanese/scim-skk                                
   Japanese                  japanese/scim-tables                             
   Japanese                  japanese/scim-tomoe                              
   Japanese                  japanese/scim-uim                                
   Japanese                  japanese/skkinput                                
   Japanese                  japanese/skkinput3                               
   Japanese                  japanese/uim-anthy                               
   Korean                    korean/ibus-hangul                               
   Korean                    korean/imhangul                                  
   Korean                    korean/nabi                                      
   Korean                    korean/scim-hangul                               
   Korean                    korean/scim-tables                               
   Vietnamese                vietnamese/xvnkb                                 
   Vietnamese                vietnamese/x-unikey                              

23.3. Finding i18n Applications

   i18n applications are programmed using i18n kits under libraries. These
   allow developers to write a simple file and translate displayed menus and
   texts to each language.

   The FreeBSD Ports Collection contains many applications with built-in
   support for wide or multibyte characters for several languages. Such
   applications include i18n in their names for easy identification. However,
   they do not always support the language needed.

   Some applications can be compiled with the specific charset. This is
   usually done in the port's Makefile or by passing a value to configure.
   Refer to the i18n documentation in the respective FreeBSD port's source
   for more information on how to determine the needed configure value or the
   port's Makefile to determine which compile options to use when building
   the port.

23.4. Locale Configuration for Specific Languages

   This section provides configuration examples for localizing a FreeBSD
   system for the Russian language. It then provides some additional
   resources for localizing other languages.

  23.4.1. Russian Language (KOI8-R Encoding)

   Originally contributed by Andrey Chernov.

   This section shows the specific settings needed to localize a FreeBSD
   system for the Russian language. Refer to Using Localization for a more
   complete description of each type of setting.

   To set this locale for the login shell, add the following lines to each
   user's ~/.login_conf:

 me:My Account:\
         :charset=KOI8-R:\
         :lang=ru_RU.KOI8-R:

   To configure the console, add the following lines to /etc/rc.conf:

 keymap="ru.koi8-r"
 scrnmap="koi8-r2cp866"
 font8x16="cp866b-8x16"
 font8x14="cp866-8x14"
 font8x8="cp866-8x8"
 mousechar_start=3

   For each ttyv entry in /etc/ttys, use cons25r as the terminal type.

   To configure printing, a special output filter is needed to convert from
   KOI8-R to CP866 since most printers with Russian characters come with
   hardware code page CP866. FreeBSD includes a default filter for this
   purpose, /usr/libexec/lpr/ru/koi2alt. To use this filter, add this entry
   to /etc/printcap:

 lp|Russian local line printer:\
         :sh:of=/usr/libexec/lpr/ru/koi2alt:\
         :lp=/dev/lpt0:sd=/var/spool/output/lpd:lf=/var/log/lpd-errs:

   Refer to printcap(5) for a more detailed explanation.

   To configure support for Russian filenames in mounted MS-DOS(R) file
   systems, include -L and the locale name when adding an entry to
   /etc/fstab:

 /dev/ad0s2      /dos/c  msdos   rw,-Lru_RU.KOI8-R 0 0

   Refer to mount_msdosfs(8) for more details.

   To configure Russian fonts for Xorg, install the
   x11-fonts/xorg-fonts-cyrillic package. Then, check the "Files" section in
   /etc/X11/xorg.conf. The following line must be added before any other
   FontPath entries:

 FontPath   "/usr/local/lib/X11/fonts/cyrillic"

   Additional Cyrillic fonts are available in the Ports Collection.

   To activate a Russian keyboard, add the following to the "Keyboard"
   section of /etc/xorg.conf:

 Option "XkbLayout"   "us,ru"
 Option "XkbOptions"  "grp:toggle"

   Make sure that XkbDisable is commented out in that file.

   For grp:toggle use Right Alt, for grp:ctrl_shift_toggle use Ctrl+Shift.
   For grp:caps_toggle use CapsLock. The old CapsLock function is still
   available in LAT mode only using Shift+CapsLock. grp:caps_toggle does not
   work in Xorg for some unknown reason.

   If the keyboard has "Windows(R)" keys, and some non-alphabetical keys are
   mapped incorrectly, add the following line to /etc/xorg.conf:

 Option "XkbVariant" ",winkeys"

  Note:

   The Russian XKB keyboard may not work with non-localized applications.
   Minimally localized applications should call a XtSetLanguageProc (NULL,
   NULL, NULL); function early in the program.

   See http://koi8.pp.ru/xwin.html for more instructions on localizing Xorg
   applications. For more general information about KOI8-R encoding, refer to
   http://koi8.pp.ru/.

  23.4.2. Additional Language-Specific Resources

   This section lists some additional resources for configuring other
   locales.

   Traditional Chinese for Taiwan

           The FreeBSD-Taiwan Project has a Chinese HOWTO for FreeBSD at
           http://netlab.cse.yzu.edu.tw/~statue/freebsd/zh-tut/.

   Greek Language Localization

           A complete article on Greek support in FreeBSD is available here,
           in Greek only, as part of the official FreeBSD Greek
           documentation.

   Japanese and Korean Language Localization

           For Japanese, refer to http://www.jp.FreeBSD.org/, and for Korean,
           refer to http://www.kr.FreeBSD.org/.

   Non-English FreeBSD Documentation

           Some FreeBSD contributors have translated parts of the FreeBSD
           documentation to other languages. They are available through links
           on the FreeBSD web site or in /usr/share/doc.

Chapter 24. Updating and Upgrading FreeBSD

   Restructured, reorganized, and parts updated by Jim Mock.
   Original work by Jordan Hubbard, Poul-Henning Kamp, John Polstra and Nik
   Clayton.
   Table of Contents

   24.1. Synopsis

   24.2. FreeBSD Update

   24.3. Updating the Documentation Set

   24.4. Tracking a Development Branch

   24.5. Updating FreeBSD from Source

   24.6. Tracking for Multiple Machines

24.1. Synopsis

   FreeBSD is under constant development between releases. Some people prefer
   to use the officially released versions, while others prefer to keep in
   sync with the latest developments. However, even official releases are
   often updated with security and other critical fixes. Regardless of the
   version used, FreeBSD provides all the necessary tools to keep the system
   updated, and allows for easy upgrades between versions. This chapter
   describes how to track the development system and the basic tools for
   keeping a FreeBSD system up-to-date.

   After reading this chapter, you will know:

     * How to keep a FreeBSD system up-to-date with freebsd-update or
       Subversion.

     * How to compare the state of an installed system against a known
       pristine copy.

     * How to keep the installed documentation up-to-date with Subversion or
       documentation ports.

     * The difference between the two development branches: FreeBSD-STABLE
       and FreeBSD-CURRENT.

     * How to rebuild and reinstall the entire base system.

   Before reading this chapter, you should:

     * Properly set up the network connection (Chapter 32, Advanced
       Networking).

     * Know how to install additional third-party software (Chapter 4,
       Installing Applications: Packages and Ports).

  Note:

   Throughout this chapter, svnlite is used to obtain and update FreeBSD
   sources. Optionally, the devel/subversion port or package may be used.

24.2. FreeBSD Update

   Written by Tom Rhodes.
   Based on notes provided by Colin Percival.

   Applying security patches in a timely manner and upgrading to a newer
   release of an operating system are important aspects of ongoing system
   administration. FreeBSD includes a utility called freebsd-update which can
   be used to perform both these tasks.

   This utility supports binary security and errata updates to FreeBSD,
   without the need to manually compile and install the patch or a new
   kernel. Binary updates are available for all architectures and releases
   currently supported by the security team. The list of supported releases
   and their estimated end-of-life dates are listed at
   https://www.FreeBSD.org/security/.

   This utility also supports operating system upgrades to minor point
   releases as well as upgrades to another release branch. Before upgrading
   to a new release, review its release announcement as it contains important
   information pertinent to the release. Release announcements are available
   from https://www.FreeBSD.org/releases/.

  Note:

   If a crontab utilizing the features of freebsd-update(8) exists, it must
   be disabled before upgrading the operating system.

   This section describes the configuration file used by freebsd-update,
   demonstrates how to apply a security patch and how to upgrade to a minor
   or major operating system release, and discusses some of the
   considerations when upgrading the operating system.

  24.2.1. The Configuration File

   The default configuration file for freebsd-update works as-is. Some users
   may wish to tweak the default configuration in /etc/freebsd-update.conf,
   allowing better control of the process. The comments in this file explain
   the available options, but the following may require a bit more
   explanation:

 # Components of the base system which should be kept updated.
 Components world kernel

   This parameter controls which parts of FreeBSD will be kept up-to-date.
   The default is to update the entire base system and the kernel. Individual
   components can instead be specified, such as src/base or src/sys. However,
   the best option is to leave this at the default as changing it to include
   specific items requires every needed item to be listed. Over time, this
   could have disastrous consequences as source code and binaries may become
   out of sync.

 # Paths which start with anything matching an entry in an IgnorePaths
 # statement will be ignored.
 IgnorePaths /boot/kernel/linker.hints

   To leave specified directories, such as /bin or /sbin, untouched during
   the update process, add their paths to this statement. This option may be
   used to prevent freebsd-update from overwriting local modifications.

 # Paths which start with anything matching an entry in an UpdateIfUnmodified
 # statement will only be updated if the contents of the file have not been
 # modified by the user (unless changes are merged; see below).
 UpdateIfUnmodified /etc/ /var/ /root/ /.cshrc /.profile

   This option will only update unmodified configuration files in the
   specified directories. Any changes made by the user will prevent the
   automatic updating of these files. There is another option,
   KeepModifiedMetadata, which will instruct freebsd-update to save the
   changes during the merge.

 # When upgrading to a new FreeBSD release, files which match MergeChanges
 # will have any local changes merged into the version from the new release.
 MergeChanges /etc/ /var/named/etc/ /boot/device.hints

   List of directories with configuration files that freebsd-update should
   attempt to merge. The file merge process is a series of diff(1) patches
   similar to mergemaster(8), but with fewer options. Merges are either
   accepted, open an editor, or cause freebsd-update to abort. When in doubt,
   backup /etc and just accept the merges. See mergemaster(8) for more
   information about mergemaster.

 # Directory in which to store downloaded updates and temporary
 # files used by FreeBSD Update.
 # WorkDir /var/db/freebsd-update

   This directory is where all patches and temporary files are placed. In
   cases where the user is doing a version upgrade, this location should have
   at least a gigabyte of disk space available.

 # When upgrading between releases, should the list of Components be
 # read strictly (StrictComponents yes) or merely as a list of components
 # which *might* be installed of which FreeBSD Update should figure out
 # which actually are installed and upgrade those (StrictComponents no)?
 # StrictComponents no

   When this option is set to yes, freebsd-update will assume that the
   Components list is complete and will not attempt to make changes outside
   of the list. Effectively, freebsd-update will attempt to update every file
   which belongs to the Components list.

  24.2.2. Applying Security Patches

   The process of applying FreeBSD security patches has been simplified,
   allowing an administrator to keep a system fully patched using
   freebsd-update. More information about FreeBSD security advisories can be
   found in Section 14.11, "FreeBSD Security Advisories".

   FreeBSD security patches may be downloaded and installed using the
   following commands. The first command will determine if any outstanding
   patches are available, and if so, will list the files that will be modifed
   if the patches are applied. The second command will apply the patches.

 # freebsd-update fetch
 # freebsd-update install

   If the update applies any kernel patches, the system will need a reboot in
   order to boot into the patched kernel. If the patch was applied to any
   running binaries, the affected applications should be restarted so that
   the patched version of the binary is used.

  Note:

   Usually, the user needs to be prepared to reboot the system. To know if a
   reboot is required by a kernel update, execute the commands
   freebsd-version -k and uname -r and if it differs a reboot is required.

   The system can be configured to automatically check for updates once every
   day by adding this entry to /etc/crontab:

 @daily                                  root    freebsd-update cron

   If patches exist, they will automatically be downloaded but will not be
   applied. The root user will be sent an email so that the patches may be
   reviewed and manually installed with freebsd-update install.

   If anything goes wrong, freebsd-update has the ability to roll back the
   last set of changes with the following command:

 # freebsd-update rollback
 Uninstalling updates... done.

   Again, the system should be restarted if the kernel or any kernel modules
   were modified and any affected binaries should be restarted.

   Only the GENERIC kernel can be automatically updated by freebsd-update. If
   a custom kernel is installed, it will have to be rebuilt and reinstalled
   after freebsd-update finishes installing the updates. The default kernel
   name is GENERIC. The uname(1) command may be used to verify its
   installation.

  Note:

   Always keep a copy of the GENERIC kernel in /boot/GENERIC. It will be
   helpful in diagnosing a variety of problems and in performing version
   upgrades. Refer to Section 24.2.3.1, "Custom Kernels with FreeBSD 9.X and
   Later" for instructions on how to get a copy of the GENERIC kernel.

   Unless the default configuration in /etc/freebsd-update.conf has been
   changed, freebsd-update will install the updated kernel sources along with
   the rest of the updates. Rebuilding and reinstalling a new custom kernel
   can then be performed in the usual way.

   The updates distributed by freebsd-update do not always involve the
   kernel. It is not necessary to rebuild a custom kernel if the kernel
   sources have not been modified by freebsd-update install. However,
   freebsd-update will always update /usr/src/sys/conf/newvers.sh. The
   current patch level, as indicated by the -p number reported by uname -r,
   is obtained from this file. Rebuilding a custom kernel, even if nothing
   else changed, allows uname to accurately report the current patch level of
   the system. This is particularly helpful when maintaining multiple
   systems, as it allows for a quick assessment of the updates installed in
   each one.

  24.2.3. Performing Major and Minor Version Upgrades

   Upgrades from one minor version of FreeBSD to another, like from
   FreeBSD 9.0 to FreeBSD 9.1, are called minor version upgrades. Major
   version upgrades occur when FreeBSD is upgraded from one major version to
   another, like from FreeBSD 9.X to FreeBSD 10.X. Both types of upgrades can
   be performed by providing freebsd-update with a release version target.

  Note:

   If the system is running a custom kernel, make sure that a copy of the
   GENERIC kernel exists in /boot/GENERIC before starting the upgrade. Refer
   to Section 24.2.3.1, "Custom Kernels with FreeBSD 9.X and Later" for
   instructions on how to get a copy of the GENERIC kernel.

   The following command, when run on a FreeBSD 9.0 system, will upgrade it
   to FreeBSD 9.1:

 # freebsd-update -r 9.1-RELEASE upgrade

   After the command has been received, freebsd-update will evaluate the
   configuration file and current system in an attempt to gather the
   information necessary to perform the upgrade. A screen listing will
   display which components have and have not been detected. For example:

 Looking up update.FreeBSD.org mirrors... 1 mirrors found.
 Fetching metadata signature for 9.0-RELEASE from update1.FreeBSD.org... done.
 Fetching metadata index... done.
 Inspecting system... done.

 The following components of FreeBSD seem to be installed:
 kernel/smp src/base src/bin src/contrib src/crypto src/etc src/games
 src/gnu src/include src/krb5 src/lib src/libexec src/release src/rescue
 src/sbin src/secure src/share src/sys src/tools src/ubin src/usbin
 world/base world/info world/lib32 world/manpages

 The following components of FreeBSD do not seem to be installed:
 kernel/generic world/catpages world/dict world/doc world/games
 world/proflibs

 Does this look reasonable (y/n)? y

   At this point, freebsd-update will attempt to download all files required
   for the upgrade. In some cases, the user may be prompted with questions
   regarding what to install or how to proceed.

   When using a custom kernel, the above step will produce a warning similar
   to the following:

 WARNING: This system is running a "MYKERNEL" kernel, which is not a
 kernel configuration distributed as part of FreeBSD 9.0-RELEASE.
 This kernel will not be updated: you MUST update the kernel manually
 before running "/usr/sbin/freebsd-update install"

   This warning may be safely ignored at this point. The updated GENERIC
   kernel will be used as an intermediate step in the upgrade process.

   Once all the patches have been downloaded to the local system, they will
   be applied. This process may take a while, depending on the speed and
   workload of the machine. Configuration files will then be merged. The
   merging process requires some user intervention as a file may be merged or
   an editor may appear on screen for a manual merge. The results of every
   successful merge will be shown to the user as the process continues. A
   failed or ignored merge will cause the process to abort. Users may wish to
   make a backup of /etc and manually merge important files, such as
   master.passwd or group at a later time.

  Note:

   The system is not being altered yet as all patching and merging is
   happening in another directory. Once all patches have been applied
   successfully, all configuration files have been merged and it seems the
   process will go smoothly, the changes can be committed to disk by the user
   using the following command:

 # freebsd-update install

   The kernel and kernel modules will be patched first. If the system is
   running with a custom kernel, use nextboot(8) to set the kernel for the
   next boot to the updated /boot/GENERIC:

 # nextboot -k GENERIC

  Warning:

   Before rebooting with the GENERIC kernel, make sure it contains all the
   drivers required for the system to boot properly and connect to the
   network, if the machine being updated is accessed remotely. In particular,
   if the running custom kernel contains built-in functionality usually
   provided by kernel modules, make sure to temporarily load these modules
   into the GENERIC kernel using the /boot/loader.conf facility. It is
   recommended to disable non-essential services as well as any disk and
   network mounts until the upgrade process is complete.

   The machine should now be restarted with the updated kernel:

 # shutdown -r now

   Once the system has come back online, restart freebsd-update using the
   following command. Since the state of the process has been saved,
   freebsd-update will not start from the beginning, but will instead move on
   to the next phase and remove all old shared libraries and object files.

 # freebsd-update install

  Note:

   Depending upon whether any library version numbers were bumped, there may
   only be two install phases instead of three.

   The upgrade is now complete. If this was a major version upgrade,
   reinstall all ports and packages as described in Section 24.2.3.2,
   "Upgrading Packages After a Major Version Upgrade".

    24.2.3.1. Custom Kernels with FreeBSD 9.X and Later

   Before using freebsd-update, ensure that a copy of the GENERIC kernel
   exists in /boot/GENERIC. If a custom kernel has only been built once, the
   kernel in /boot/kernel.old is the GENERIC kernel. Simply rename this
   directory to /boot/GENERIC.

   If a custom kernel has been built more than once or if it is unknown how
   many times the custom kernel has been built, obtain a copy of the GENERIC
   kernel that matches the current version of the operating system. If
   physical access to the system is available, a copy of the GENERIC kernel
   can be installed from the installation media:

 # mount /cdrom
 # cd /cdrom/usr/freebsd-dist
 # tar -C/ -xvf kernel.txz boot/kernel/kernel

   Alternately, the GENERIC kernel may be rebuilt and installed from source:

 # cd /usr/src
 # make kernel __MAKE_CONF=/dev/null SRCCONF=/dev/null

   For this kernel to be identified as the GENERIC kernel by freebsd-update,
   the GENERIC configuration file must not have been modified in any way. It
   is also suggested that the kernel is built without any other special
   options.

   Rebooting into the GENERIC kernel is not required as freebsd-update only
   needs /boot/GENERIC to exist.

    24.2.3.2. Upgrading Packages After a Major Version Upgrade

   Generally, installed applications will continue to work without problems
   after minor version upgrades. Major versions use different Application
   Binary Interfaces (ABIs), which will break most third-party applications.
   After a major version upgrade, all installed packages and ports need to be
   upgraded. Packages can be upgraded using pkg upgrade. To upgrade installed
   ports, use a utility such as ports-mgmt/portmaster.

   A forced upgrade of all installed packages will replace the packages with
   fresh versions from the repository even if the version number has not
   increased. This is required because of the ABI version change when
   upgrading between major versions of FreeBSD. The forced upgrade can be
   accomplished by performing:

 # pkg-static upgrade -f

   A rebuild of all installed applications can be accomplished with this
   command:

 # portmaster -af

   This command will display the configuration screens for each application
   that has configurable options and wait for the user to interact with those
   screens. To prevent this behavior, and use only the default options,
   include -G in the above command.

   Once the software upgrades are complete, finish the upgrade process with a
   final call to freebsd-update in order to tie up all the loose ends in the
   upgrade process:

 # freebsd-update install

   If the GENERIC kernel was temporarily used, this is the time to build and
   install a new custom kernel using the instructions in Chapter 8,
   Configuring the FreeBSD Kernel.

   Reboot the machine into the new FreeBSD version. The upgrade process is
   now complete.

  24.2.4. System State Comparison

   The state of the installed FreeBSD version against a known good copy can
   be tested using freebsd-update IDS. This command evaluates the current
   version of system utilities, libraries, and configuration files and can be
   used as a built-in Intrusion Detection System (IDS).

  Warning:

   This command is not a replacement for a real IDS such as security/snort.
   As freebsd-update stores data on disk, the possibility of tampering is
   evident. While this possibility may be reduced using kern.securelevel and
   by storing the freebsd-update data on a read-only file system when not in
   use, a better solution would be to compare the system against a secure
   disk, such as a DVD or securely stored external USB disk device. An
   alternative method for providing IDS functionality using a built-in
   utility is described in Section 14.2.6, "Binary Verification"

   To begin the comparison, specify the output file to save the results to:

 # freebsd-update IDS >> outfile.ids

   The system will now be inspected and a lengthy listing of files, along
   with the SHA256 hash values for both the known value in the release and
   the current installation, will be sent to the specified output file.

   The entries in the listing are extremely long, but the output format may
   be easily parsed. For instance, to obtain a list of all files which differ
   from those in the release, issue the following command:

 # cat outfile.ids | awk '{ print $1 }' | more
 /etc/master.passwd
 /etc/motd
 /etc/passwd
 /etc/pf.conf

   This sample output has been truncated as many more files exist. Some files
   have natural modifications. For example, /etc/passwd will be modified if
   users have been added to the system. Kernel modules may differ as
   freebsd-update may have updated them. To exclude specific files or
   directories, add them to the IDSIgnorePaths option in
   /etc/freebsd-update.conf.

24.3. Updating the Documentation Set

   Documentation is an integral part of the FreeBSD operating system. While
   an up-to-date version of the FreeBSD documentation is always available on
   the FreeBSD web site (https://www.freebsd.org/doc/), it can be handy to
   have an up-to-date, local copy of the FreeBSD website, handbooks, FAQ, and
   articles.

   This section describes how to use either source or the FreeBSD Ports
   Collection to keep a local copy of the FreeBSD documentation up-to-date.

   For information on editing and submitting corrections to the
   documentation, refer to the FreeBSD Documentation Project Primer for New
   Contributors
   (https://www.freebsd.org/doc/en_US.ISO8859-1/books/fdp-primer/).

  24.3.1. Updating Documentation from Source

   Rebuilding the FreeBSD documentation from source requires a collection of
   tools which are not part of the FreeBSD base system. The required tools
   can be installed from the textproc/docproj package or port developed by
   the FreeBSD Documentation Project.

   Once installed, use svnlite to fetch a clean copy of the documentation
   source:

 # svnlite checkout https://svn.FreeBSD.org/doc/head /usr/doc

   The initial download of the documentation sources may take a while. Let it
   run until it completes.

   Future updates of the documentation sources may be fetched by running:

 # svnlite update /usr/doc

   Once an up-to-date snapshot of the documentation sources has been fetched
   to /usr/doc, everything is ready for an update of the installed
   documentation.

   A full update of all available languages may be performed by typing:

 # cd /usr/doc
 # make install clean

   If an update of only a specific language is desired, make can be invoked
   in a language-specific subdirectory of /usr/doc:

 # cd /usr/doc/en_US.ISO8859-1
 # make install clean

   An alternative way of updating the documentation is to run this command
   from /usr/doc or the desired language-specific subdirectory:

 # make update

   The output formats that will be installed may be specified by setting
   FORMATS:

 # cd /usr/doc
 # make FORMATS='html html-split' install clean

   Several options are available to ease the process of updating only parts
   of the documentation, or the build of specific translations. These options
   can be set either as system-wide options in /etc/make.conf, or as
   command-line options passed to make.

   The options include:

   DOC_LANG

           The list of languages and encodings to build and install, such as
           en_US.ISO8859-1 for English documentation.

   FORMATS

           A single format or a list of output formats to be built.
           Currently, html, html-split, txt, ps, and pdf are supported.

   DOCDIR

           Where to install the documentation. It defaults to /usr/share/doc.

   For more make variables supported as system-wide options in FreeBSD, refer
   to make.conf(5).

  24.3.2. Updating Documentation from Ports

   Based on the work of Marc Fonvieille.

   The previous section presented a method for updating the FreeBSD
   documentation from sources. This section describes an alternative method
   which uses the Ports Collection and makes it possible to:

     * Install pre-built packages of the documentation, without having to
       locally build anything or install the documentation toolchain.

     * Build the documentation sources through the ports framework, making
       the checkout and build steps a bit easier.

   This method of updating the FreeBSD documentation is supported by a set of
   documentation ports and packages which are updated by the Documentation
   Engineering Team <doceng@FreeBSD.org> on a monthly basis. These are listed
   in the FreeBSD Ports Collection, under the docs category
   (http://www.freshports.org/docs/).

   Organization of the documentation ports is as follows:

     * The misc/freebsd-doc-en package or port installs all of the English
       documentation.

     * The misc/freebsd-doc-all meta-package or port installs all
       documentation in all available languages.

     * There is a package and port for each translation, such as
       misc/freebsd-doc-hu for the Hungarian documentation.

   When binary packages are used, the FreeBSD documentation will be installed
   in all available formats for the given language. For example, the
   following command will install the latest package of the Hungarian
   documentation:

 # pkg install hu-freebsd-doc

  Note:

   Packages use a format that differs from the corresponding port's name:
   lang-freebsd-doc, where lang is the short format of the language code,
   such as hu for Hungarian, or zh_cn for Simplified Chinese.

   To specify the format of the documentation, build the port instead of
   installing the package. For example, to build and install the English
   documentation:

 # cd /usr/ports/misc/freebsd-doc-en
 # make install clean

   The port provides a configuration menu where the format to build and
   install can be specified. By default, split HTML, similar to the format
   used on http://www.FreeBSD.org, and PDF are selected.

   Alternately, several make options can be specified when building a
   documentation port, including:

   WITH_HTML

           Builds the HTML format with a single HTML file per document. The
           formatted documentation is saved to a file called article.html, or
           book.html.

   WITH_PDF

           The formatted documentation is saved to a file called article.pdf
           or book.pdf.

   DOCBASE

           Specifies where to install the documentation. It defaults to
           /usr/local/share/doc/freebsd.

   This example uses variables to install the Hungarian documentation as a
   PDF in the specified directory:

 # cd /usr/ports/misc/freebsd-doc-hu
 # make -DWITH_PDF DOCBASE=share/doc/freebsd/hu install clean

   Documentation packages or ports can be updated using the instructions in
   Chapter 4, Installing Applications: Packages and Ports. For example, the
   following command updates the installed Hungarian documentation using
   ports-mgmt/portmaster by using packages only:

 # portmaster -PP hu-freebsd-doc

24.4. Tracking a Development Branch

   FreeBSD has two development branches: FreeBSD-CURRENT and FreeBSD-STABLE.

   This section provides an explanation of each branch and its intended
   audience, as well as how to keep a system up-to-date with each respective
   branch.

  24.4.1. Using FreeBSD-CURRENT

   FreeBSD-CURRENT is the "bleeding edge" of FreeBSD development and
   FreeBSD-CURRENT users are expected to have a high degree of technical
   skill. Less technical users who wish to track a development branch should
   track FreeBSD-STABLE instead.

   FreeBSD-CURRENT is the very latest source code for FreeBSD and includes
   works in progress, experimental changes, and transitional mechanisms that
   might or might not be present in the next official release. While many
   FreeBSD developers compile the FreeBSD-CURRENT source code daily, there
   are short periods of time when the source may not be buildable. These
   problems are resolved as quickly as possible, but whether or not
   FreeBSD-CURRENT brings disaster or new functionality can be a matter of
   when the source code was synced.

   FreeBSD-CURRENT is made available for three primary interest groups:

    1. Members of the FreeBSD community who are actively working on some part
       of the source tree.

    2. Members of the FreeBSD community who are active testers. They are
       willing to spend time solving problems, making topical suggestions on
       changes and the general direction of FreeBSD, and submitting patches.

    3. Users who wish to keep an eye on things, use the current source for
       reference purposes, or make the occasional comment or code
       contribution.

   FreeBSD-CURRENT should not be considered a fast-track to getting new
   features before the next release as pre-release features are not yet fully
   tested and most likely contain bugs. It is not a quick way of getting bug
   fixes as any given commit is just as likely to introduce new bugs as to
   fix existing ones. FreeBSD-CURRENT is not in any way "officially
   supported".

   To track FreeBSD-CURRENT:

    1. Join the freebsd-current and the svn-src-head lists. This is essential
       in order to see the comments that people are making about the current
       state of the system and to receive important bulletins about the
       current state of FreeBSD-CURRENT.

       The svn-src-head list records the commit log entry for each change as
       it is made, along with any pertinent information on possible side
       effects.

       To join these lists, go to http://lists.FreeBSD.org/mailman/listinfo,
       click on the list to subscribe to, and follow the instructions. In
       order to track changes to the whole source tree, not just the changes
       to FreeBSD-CURRENT, subscribe to the svn-src-all list.

    2. Synchronize with the FreeBSD-CURRENT sources. Typically, svnlite is
       used to check out the -CURRENT code from the head branch of one of the
       Subversion mirror sites listed in Section A.3.6, "Subversion Mirror
       Sites".

    3. Due to the size of the repository, some users choose to only
       synchronize the sections of source that interest them or which they
       are contributing patches to. However, users that plan to compile the
       operating system from source must download all of FreeBSD-CURRENT, not
       just selected portions.

       Before compiling FreeBSD-CURRENT , read /usr/src/Makefile very
       carefully and follow the instructions in Section 24.5, "Updating
       FreeBSD from Source". Read the FreeBSD-CURRENT mailing list and
       /usr/src/UPDATING to stay up-to-date on other bootstrapping procedures
       that sometimes become necessary on the road to the next release.

    4. Be active! FreeBSD-CURRENT users are encouraged to submit their
       suggestions for enhancements or bug fixes. Suggestions with
       accompanying code are always welcome.

  24.4.2. Using FreeBSD-STABLE

   FreeBSD-STABLE is the development branch from which major releases are
   made. Changes go into this branch at a slower pace and with the general
   assumption that they have first been tested in FreeBSD-CURRENT. This is
   still a development branch and, at any given time, the sources for
   FreeBSD-STABLE may or may not be suitable for general use. It is simply
   another engineering development track, not a resource for end-users. Users
   who do not have the resources to perform testing should instead run the
   most recent release of FreeBSD.

   Those interested in tracking or contributing to the FreeBSD development
   process, especially as it relates to the next release of FreeBSD, should
   consider following FreeBSD-STABLE.

   While the FreeBSD-STABLE branch should compile and run at all times, this
   cannot be guaranteed. Since more people run FreeBSD-STABLE than
   FreeBSD-CURRENT, it is inevitable that bugs and corner cases will
   sometimes be found in FreeBSD-STABLE that were not apparent in
   FreeBSD-CURRENT. For this reason, one should not blindly track
   FreeBSD-STABLE. It is particularly important not to update any production
   servers to FreeBSD-STABLE without thoroughly testing the code in a
   development or testing environment.

   To track FreeBSD-STABLE:

    1. Join the freebsd-stable list in order to stay informed of build
       dependencies that may appear in FreeBSD-STABLE or any other issues
       requiring special attention. Developers will also make announcements
       in this mailing list when they are contemplating some controversial
       fix or update, giving the users a chance to respond if they have any
       issues to raise concerning the proposed change.

       Join the relevant svn list for the branch being tracked. For example,
       users tracking the 9-STABLE branch should join the svn-src-stable-9
       list. This list records the commit log entry for each change as it is
       made, along with any pertinent information on possible side effects.

       To join these lists, go to http://lists.FreeBSD.org/mailman/listinfo,
       click on the list to subscribe to, and follow the instructions. In
       order to track changes for the whole source tree, subscribe to
       svn-src-all.

    2. To install a new FreeBSD-STABLE system, install the most recent
       FreeBSD-STABLE release from the FreeBSD mirror sites or use a monthly
       snapshot built from FreeBSD-STABLE. Refer to www.freebsd.org/snapshots
       for more information about snapshots.

       To compile or upgrade to an existing FreeBSD system to FreeBSD-STABLE,
       use svn to check out the source for the desired branch. Branch names,
       such as stable/9, are listed at www.freebsd.org/releng.

    3. Before compiling or upgrading to FreeBSD-STABLE , read
       /usr/src/Makefile carefully and follow the instructions in
       Section 24.5, "Updating FreeBSD from Source". Read the FreeBSD-STABLE
       mailing list and /usr/src/UPDATING to keep up-to-date on other
       bootstrapping procedures that sometimes become necessary on the road
       to the next release.

24.5. Updating FreeBSD from Source

   Updating FreeBSD by compiling from source offers several advantages over
   binary updates. Code can be built with options to take advantage of
   specific hardware. Parts of the base system can be built with non-default
   settings, or left out entirely where they are not needed or desired. The
   build process takes longer to update a system than just installing binary
   updates, but allows complete customization to produce a tailored version
   of FreeBSD.

  24.5.1. Quick Start

   This is a quick reference for the typical steps used to update FreeBSD by
   building from source. Later sections describe the process in more detail.

     * Update and Build

 # svnlite update /usr/src  1
 check /usr/src/UPDATING  2
 # cd /usr/src          3
 # make -j4 buildworld  4
 # make -j4 kernel      5
 # shutdown -r now      6
 # cd /usr/src          7
 # make installworld    8
 # mergemaster -Ui      9
 # shutdown -r now      10

       1  Get the latest version of the source. See Section 24.5.3, "Updating 
          the Source" for more information on obtaining and updating source.  
       2  Check /usr/src/UPDATING for any manual steps required before or     
          after building from source.                                         
       3  Go to the source directory.                                         
       4  Compile the world, everything except the kernel.                    
       5  Compile and install the kernel. This is equivalent to make          
          buildkernel installkernel.                                          
       6  Reboot the system to the new kernel.                                
       7  Go to the source directory.                                         
       8  Install the world.                                                  
       9  Update and merge configuration files in /etc/.                      
       10 Restart the system to use the newly-built world and kernel.         

  24.5.2. Preparing for a Source Update

   Read /usr/src/UPDATING. Any manual steps that must be performed before or
   after an update are described in this file.

  24.5.3. Updating the Source

   FreeBSD source code is located in /usr/src/. The preferred method of
   updating this source is through the Subversion version control system.
   Verify that the source code is under version control:

 # svnlite info /usr/src
 Path: /usr/src
 Working Copy Root Path: /usr/src
 ...

   This indicates that /usr/src/ is under version control and can be updated
   with svnlite(1):

 # svnlite update /usr/src

   The update process can take some time if the directory has not been
   updated recently. After it finishes, the source code is up to date and the
   build process described in the next section can begin.

  Obtaining the Source:

   If the output says '/usr/src' is not a working copy, the files there are
   missing or were installed with a different method. A new checkout of the
   source is required.

   Table 24.1. FreeBSD Versions and Repository Paths

   +------------------------------------------------------------------------+
   | uname -r Output | Repository Path |            Description             |
   |-----------------+-----------------+------------------------------------|
   |                 |                 | The Release version plus only      |
   | X.Y-RELEASE     | base/releng/X.Y | critical security and bug fix      |
   |                 |                 | patches. This branch is            |
   |                 |                 | recommended for most users.        |
   |-----------------+-----------------+------------------------------------|
   |                 |                 | The Release version plus all       |
   |                 |                 | additional development on that     |
   |                 |                 | branch. STABLE refers to the       |
   |                 |                 | Applications Binary Interface      |
   |                 |                 | (ABI) not changing, so software    |
   |                 |                 | compiled for earlier versions      |
   |                 |                 | still runs. For example, software  |
   | X.Y-STABLE      | base/stable/X   | compiled to run on FreeBSD 10.1    |
   |                 |                 | will still run on FreeBSD          |
   |                 |                 | 10-STABLE compiled later.          |
   |                 |                 |                                    |
   |                 |                 | STABLE branches occasionally have  |
   |                 |                 | bugs or incompatibilities which    |
   |                 |                 | might affect users, although these |
   |                 |                 | are typically fixed quickly.       |
   |-----------------+-----------------+------------------------------------|
   |                 |                 | The latest unreleased development  |
   |                 |                 | version of FreeBSD. The CURRENT    |
   | X-CURRENT       | base/head/      | branch can have major bugs or      |
   |                 |                 | incompatibilities and is           |
   |                 |                 | recommended only for advanced      |
   |                 |                 | users.                             |
   +------------------------------------------------------------------------+

   Determine which version of FreeBSD is being used with uname(1):

 # uname -r
 10.3-RELEASE

   Based on Table 24.1, "FreeBSD Versions and Repository Paths", the source
   used to update 10.3-RELEASE has a repository path of base/releng/10.3.
   That path is used when checking out the source:

 # mv /usr/src /usr/src.bak  1
 # svnlite checkout https://svn.freebsd.org/base/releng/10.3 /usr/src  2

   1 Move the old directory out of the way. If there are no local             
     modifications in this directory, it can be deleted.                      
   2 The path from Table 24.1, "FreeBSD Versions and Repository Paths" is     
     added to the repository URL. The third parameter is the destination      
     directory for the source code on the local system.                       

  24.5.4. Building from Source

   The world, or all of the operating system except the kernel, is compiled.
   This is done first to provide up-to-date tools to build the kernel. Then
   the kernel itself is built:

 # cd /usr/src
 # make buildworld
 # make buildkernel

   The compiled code is written to /usr/obj.

   These are the basic steps. Additional options to control the build are
   described below.

    24.5.4.1. Performing a Clean Build

   Some versions of the FreeBSD build system leave previously-compiled code
   in the temporary object directory, /usr/obj. This can speed up later
   builds by avoiding recompiling code that has not changed. To force a clean
   rebuild of everything, use cleanworld before starting a build:

 # make cleanworld

    24.5.4.2. Setting the Number of Jobs

   Increasing the number of build jobs on multi-core processors can improve
   build speed. Determine the number of cores with sysctl hw.ncpu. Processors
   vary, as do the build systems used with different versions of FreeBSD, so
   testing is the only sure method to tell how a different number of jobs
   affects the build speed. For a starting point, consider values between
   half and double the number of cores. The number of jobs is specified with
   -j.

   Example 24.1. Increasing the Number of Build Jobs

   Building the world and kernel with four jobs:

 # make -j4 buildworld buildkernel

    24.5.4.3. Building Only the Kernel

   A buildworld must be completed if the source code has changed. After that,
   a buildkernel to build a kernel can be run at any time. To build just the
   kernel:

 # cd /usr/src
 # make buildkernel

    24.5.4.4. Building a Custom Kernel

   The standard FreeBSD kernel is based on a kernel config file called
   GENERIC. The GENERIC kernel includes the most commonly-needed device
   drivers and options. Sometimes it is useful or necessary to build a custom
   kernel, adding or removing device drivers or options to fit a specific
   need.

   For example, someone developing a small embedded computer with severely
   limited RAM could remove unneeded device drivers or options to make the
   kernel slightly smaller.

   Kernel config files are located in /usr/src/sys/arch/conf/, where arch is
   the output from uname -m. On most computers, that is amd64, giving a
   config file directory of /usr/src/sys/amd64/conf/.

  Tip:

   /usr/src can be deleted or recreated, so it is preferable to keep custom
   kernel config files in a separate directory, like /root. Link the kernel
   config file into the conf directory. If that directory is deleted or
   overwritten, the kernel config can be re-linked into the new one.

   A custom config file can be created by copying the GENERIC config file. In
   this example, the new custom kernel is for a storage server, so is named
   STORAGESERVER:

 # cp /usr/src/sys/amd64/conf/GENERIC /root/STORAGESERVER
 # cd /usr/src/sys/amd64/conf
 # ln -s /root/STORAGESERVER .

   /root/STORAGESERVER is then edited, adding or removing devices or options
   as shown in config(5).

   The custom kernel is built by setting KERNCONF to the kernel config file
   on the command line:

 # make buildkernel KERNCONF=STORAGESERVER

  24.5.5. Installing the Compiled Code

   After the buildworld and buildkernel steps have been completed, the new
   kernel and world are installed:

 # cd /usr/src
 # make installkernel
 # shutdown -r now
 # cd /usr/src
 # make installworld
 # shutdown -r now

   If a custom kernel was built, KERNCONF must also be set to use the new
   custom kernel:

 # cd /usr/src
 # make installkernel KERNCONF=STORAGESERVER
 # shutdown -r now
 # cd /usr/src
 # make installworld
 # shutdown -r now

  24.5.6. Completing the Update

   A few final tasks complete the update. Any modified configuration files
   are merged with the new versions, outdated libraries are located and
   removed, then the system is restarted.

    24.5.6.1. Merging Configuration Files with mergemaster(8)

   mergemaster(8) provides an easy way to merge changes that have been made
   to system configuration files with new versions of those files.

   With -Ui, mergemaster(8) automatically updates files that have not been
   user-modified and installs new files that are not already present:

 # mergemaster -Ui

   If a file must be manually merged, an interactive display allows the user
   to choose which portions of the files are kept. See mergemaster(8) for
   more information.

    24.5.6.2. Checking for Outdated Files and Libraries

   Some obsolete files or directories can remain after an update. These files
   can be located:

 # make check-old

   and deleted:

 # make delete-old

   Some obsolete libraries can also remain. These can be detected with:

 # make check-old-libs

   and deleted with

 # make delete-old-libs

   Programs which were still using those old libraries will stop working when
   the library has been deleted. These programs must be rebuilt or replaced
   after deleting the old libraries.

  Tip:

   When all the old files or directories are known to be safe to delete,
   pressing y and Enter to delete each file can be avoided by setting
   BATCH_DELETE_OLD_FILES in the command. For example:

 # make BATCH_DELETE_OLD_FILES=yes delete-old-libs

    24.5.6.3. Restarting After the Update

   The last step after updating is to restart the computer so all the changes
   take effect:

 # shutdown -r now

24.6. Tracking for Multiple Machines

   Contributed by Mike Meyer.

   When multiple machines need to track the same source tree, it is a waste
   of disk space, network bandwidth, and CPU cycles to have each system
   download the sources and rebuild everything. The solution is to have one
   machine do most of the work, while the rest of the machines mount that
   work via NFS. This section outlines a method of doing so. For more
   information about using NFS, refer to Section 30.3, "Network File System
   (NFS)".

   First, identify a set of machines which will run the same set of binaries,
   known as a build set. Each machine can have a custom kernel, but will run
   the same userland binaries. From that set, choose a machine to be the
   build machine that the world and kernel are built on. Ideally, this is a
   fast machine that has sufficient spare CPU to run make buildworld and make
   buildkernel.

   Select a machine to be the test machine, which will test software updates
   before they are put into production. This must be a machine that can
   afford to be down for an extended period of time. It can be the build
   machine, but need not be.

   All the machines in this build set need to mount /usr/obj and /usr/src
   from the build machine via NFS. For multiple build sets, /usr/src should
   be on one build machine, and NFS mounted on the rest.

   Ensure that /etc/make.conf and /etc/src.conf on all the machines in the
   build set agree with the build machine. That means that the build machine
   must build all the parts of the base system that any machine in the build
   set is going to install. Also, each build machine should have its kernel
   name set with KERNCONF in /etc/make.conf, and the build machine should
   list them all in its KERNCONF, listing its own kernel first. The build
   machine must have the kernel configuration files for each machine in its
   /usr/src/sys/arch/conf.

   On the build machine, build the kernel and world as described in
   Section 24.5, "Updating FreeBSD from Source", but do not install anything
   on the build machine. Instead, install the built kernel on the test
   machine. On the test machine, mount /usr/src and /usr/obj via NFS. Then,
   run shutdown now to go to single-user mode in order to install the new
   kernel and world and run mergemaster as usual. When done, reboot to return
   to normal multi-user operations.

   After verifying that everything on the test machine is working properly,
   use the same procedure to install the new software on each of the other
   machines in the build set.

   The same methodology can be used for the ports tree. The first step is to
   share /usr/ports via NFS to all the machines in the build set. To
   configure /etc/make.conf to share distfiles, set DISTDIR to a common
   shared directory that is writable by whichever user root is mapped to by
   the NFS mount. Each machine should set WRKDIRPREFIX to a local build
   directory, if ports are to be built locally. Alternately, if the build
   system is to build and distribute packages to the machines in the build
   set, set PACKAGES on the build system to a directory similar to DISTDIR.

Chapter 25. DTrace

   Written by Tom Rhodes.
   Table of Contents

   25.1. Synopsis

   25.2. Implementation Differences

   25.3. Enabling DTrace Support

   25.4. Using DTrace

25.1. Synopsis

   DTrace, also known as Dynamic Tracing, was developed by Sun(TM) as a tool
   for locating performance bottlenecks in production and pre-production
   systems. In addition to diagnosing performance problems, DTrace can be
   used to help investigate and debug unexpected behavior in both the FreeBSD
   kernel and in userland programs.

   DTrace is a remarkable profiling tool, with an impressive array of
   features for diagnosing system issues. It may also be used to run
   pre-written scripts to take advantage of its capabilities. Users can
   author their own utilities using the DTrace D Language, allowing them to
   customize their profiling based on specific needs.

   The FreeBSD implementation provides full support for kernel DTrace and
   experimental support for userland DTrace. Userland DTrace allows users to
   perform function boundary tracing for userland programs using the pid
   provider, and to insert static probes into userland programs for later
   tracing. Some ports, such as databases/postgresql12-server and lang/php74
   have a DTrace option to enable static probes.

   The official guide to DTrace is maintained by the Illumos project at
   DTrace Guide.

   After reading this chapter, you will know:

     * What DTrace is and what features it provides.

     * Differences between the Solaris(TM) DTrace implementation and the one
       provided by FreeBSD.

     * How to enable and use DTrace on FreeBSD.

   Before reading this chapter, you should:

     * Understand UNIX(R) and FreeBSD basics (Chapter 3, FreeBSD Basics).

     * Have some familiarity with security and how it pertains to FreeBSD
       (Chapter 14, Security).

25.2. Implementation Differences

   While the DTrace in FreeBSD is similar to that found in Solaris(TM),
   differences do exist. The primary difference is that in FreeBSD, DTrace is
   implemented as a set of kernel modules and DTrace can not be used until
   the modules are loaded. To load all of the necessary modules:

 # kldload dtraceall

   Beginning with FreeBSD 10.0-RELEASE, the modules are automatically loaded
   when dtrace is run.

   FreeBSD uses the DDB_CTF kernel option to enable support for loading CTF
   data from kernel modules and the kernel itself. CTF is the Solaris(TM)
   Compact C Type Format which encapsulates a reduced form of debugging
   information similar to DWARF and the venerable stabs. CTF data is added to
   binaries by the ctfconvert and ctfmerge build tools. The ctfconvert
   utility parses DWARF ELF debug sections created by the compiler and
   ctfmerge merges CTF ELF sections from objects into either executables or
   shared libraries.

   Some different providers exist for FreeBSD than for Solaris(TM). Most
   notable is the dtmalloc provider, which allows tracing malloc() by type in
   the FreeBSD kernel. Some of the providers found in Solaris(TM), such as
   cpc and mib, are not present in FreeBSD. These may appear in future
   versions of FreeBSD. Moreover, some of the providers available in both
   operating systems are not compatible, in the sense that their probes have
   different argument types. Thus, D scripts written on Solaris(TM) may or
   may not work unmodified on FreeBSD, and vice versa.

   Due to security differences, only root may use DTrace on FreeBSD.
   Solaris(TM) has a few low level security checks which do not yet exist in
   FreeBSD. As such, the /dev/dtrace/dtrace is strictly limited to root.

   DTrace falls under the Common Development and Distribution License (CDDL)
   license. To view this license on FreeBSD, see
   /usr/src/cddl/contrib/opensolaris/OPENSOLARIS.LICENSE or view it online at
   http://opensource.org/licenses/CDDL-1.0. While a FreeBSD kernel with
   DTrace support is BSD licensed, the CDDL is used when the modules are
   distributed in binary form or the binaries are loaded.

25.3. Enabling DTrace Support

   In FreeBSD 9.2 and 10.0, DTrace support is built into the GENERIC kernel.
   Users of earlier versions of FreeBSD or who prefer to statically compile
   in DTrace support should add the following lines to a custom kernel
   configuration file and recompile the kernel using the instructions in
   Chapter 8, Configuring the FreeBSD Kernel:

 options         KDTRACE_HOOKS
 options         DDB_CTF
 makeoptions     DEBUG=-g
 makeoptions     WITH_CTF=1

   Users of the AMD64 architecture should also add this line:

 options         KDTRACE_FRAME

   This option provides support for FBT. While DTrace will work without this
   option, there will be limited support for function boundary tracing.

   Once the FreeBSD system has rebooted into the new kernel, or the DTrace
   kernel modules have been loaded using kldload dtraceall, the system will
   need support for the Korn shell as the DTrace Toolkit has several
   utilities written in ksh. Make sure that the shells/ksh93 package or port
   is installed. It is also possible to run these tools under shells/pdksh or
   shells/mksh.

   Finally, install the current DTrace Toolkit, a collection of ready-made
   scripts for collecting system information. There are scripts to check open
   files, memory, CPU usage, and a lot more. FreeBSD 10 installs a few of
   these scripts into /usr/share/dtrace. On other FreeBSD versions, or to
   install the full DTrace Toolkit, use the sysutils/DTraceToolkit package or
   port.

  Note:

   The scripts found in /usr/share/dtrace have been specifically ported to
   FreeBSD. Not all of the scripts found in the DTrace Toolkit will work
   as-is on FreeBSD and some scripts may require some effort in order for
   them to work on FreeBSD.

   The DTrace Toolkit includes many scripts in the special language of
   DTrace. This language is called the D language and it is very similar to
   C++. An in depth discussion of the language is beyond the scope of this
   document. It is covered extensively in the Illumos Dynamic Tracing Guide.

25.4. Using DTrace

   DTrace scripts consist of a list of one or more probes, or instrumentation
   points, where each probe is associated with an action. Whenever the
   condition for a probe is met, the associated action is executed. For
   example, an action may occur when a file is opened, a process is started,
   or a line of code is executed. The action might be to log some information
   or to modify context variables. The reading and writing of context
   variables allows probes to share information and to cooperatively analyze
   the correlation of different events.

   To view all probes, the administrator can execute the following command:

 # dtrace -l | more

   Each probe has an ID, a PROVIDER (dtrace or fbt), a MODULE, and a FUNCTION
   NAME. Refer to dtrace(1) for more information about this command.

   The examples in this section provide an overview of how to use two of the
   fully supported scripts from the DTrace Toolkit: the hotkernel and
   procsystime scripts.

   The hotkernel script is designed to identify which function is using the
   most kernel time. It will produce output similar to the following:

 # cd /usr/local/share/dtrace-toolkit
 # ./hotkernel
 Sampling... Hit Ctrl-C to end.

   As instructed, use the Ctrl+C key combination to stop the process. Upon
   termination, the script will display a list of kernel functions and timing
   information, sorting the output in increasing order of time:

 kernel`_thread_lock_flags                                   2   0.0%
 0xc1097063                                                  2   0.0%
 kernel`sched_userret                                        2   0.0%
 kernel`kern_select                                          2   0.0%
 kernel`generic_copyin                                       3   0.0%
 kernel`_mtx_assert                                          3   0.0%
 kernel`vm_fault                                             3   0.0%
 kernel`sopoll_generic                                       3   0.0%
 kernel`fixup_filename                                       4   0.0%
 kernel`_isitmyx                                             4   0.0%
 kernel`find_instance                                        4   0.0%
 kernel`_mtx_unlock_flags                                    5   0.0%
 kernel`syscall                                              5   0.0%
 kernel`DELAY                                                5   0.0%
 0xc108a253                                                  6   0.0%
 kernel`witness_lock                                         7   0.0%
 kernel`read_aux_data_no_wait                                7   0.0%
 kernel`Xint0x80_syscall                                     7   0.0%
 kernel`witness_checkorder                                   7   0.0%
 kernel`sse2_pagezero                                        8   0.0%
 kernel`strncmp                                              9   0.0%
 kernel`spinlock_exit                                       10   0.0%
 kernel`_mtx_lock_flags                                     11   0.0%
 kernel`witness_unlock                                      15   0.0%
 kernel`sched_idletd                                       137   0.3%
 0xc10981a5                                              42139  99.3%

   This script will also work with kernel modules. To use this feature, run
   the script with -m:

 # ./hotkernel -m
 Sampling... Hit Ctrl-C to end.
 ^C
 MODULE                                                  COUNT   PCNT
 0xc107882e                                                  1   0.0%
 0xc10e6aa4                                                  1   0.0%
 0xc1076983                                                  1   0.0%
 0xc109708a                                                  1   0.0%
 0xc1075a5d                                                  1   0.0%
 0xc1077325                                                  1   0.0%
 0xc108a245                                                  1   0.0%
 0xc107730d                                                  1   0.0%
 0xc1097063                                                  2   0.0%
 0xc108a253                                                 73   0.0%
 kernel                                                    874   0.4%
 0xc10981a5                                             213781  99.6%

   The procsystime script captures and prints the system call time usage for
   a given process ID (PID) or process name. In the following example, a new
   instance of /bin/csh was spawned. Then, procsystime was executed and
   remained waiting while a few commands were typed on the other incarnation
   of csh. These are the results of this test:

 # ./procsystime -n csh
 Tracing... Hit Ctrl-C to end...
 ^C

 Elapsed Times for processes csh,

          SYSCALL          TIME (ns)
           getpid               6131
        sigreturn               8121
            close              19127
            fcntl              19959
              dup              26955
          setpgid              28070
             stat              31899
        setitimer              40938
            wait4              62717
        sigaction              67372
      sigprocmask             119091
     gettimeofday             183710
            write             263242
           execve             492547
            ioctl             770073
            vfork            3258923
       sigsuspend            6985124
             read         3988049784

   As shown, the read() system call used the most time in nanoseconds while
   the getpid() system call used the least amount of time.

Chapter 26. USB Device Mode / USB OTG

   Table of Contents

   26.1. Synopsis

   26.2. USB Virtual Serial Ports

   26.3. USB Device Mode Network Interfaces

   26.4. USB Virtual Storage Device

26.1. Synopsis

   Written by Edward Tomasz Napierala.

   This chapter covers the use of USB Device Mode and USB On The Go (USB OTG)
   in FreeBSD. This includes virtual serial consoles, virtual network
   interfaces, and virtual USB drives.

   When running on hardware that supports USB device mode or USB OTG, like
   that built into many embedded boards, the FreeBSD USB stack can run in
   device mode. Device mode makes it possible for the computer to present
   itself as different kinds of USB device classes, including serial ports,
   network adapters, and mass storage, or a combination thereof. A USB host
   like a laptop or desktop computer is able to access them just like
   physical USB devices. Device mode is sometimes called the "USB gadget
   mode".

   There are two basic ways the hardware can provide the device mode
   functionality: with a separate "client port", which only supports the
   device mode, and with a USB OTG port, which can provide both device and
   host mode. For USB OTG ports, the USB stack switches between host-side and
   device-side automatically, depending on what is connected to the port.
   Connecting a USB device like a memory stick to the port causes FreeBSD to
   switch to host mode. Connecting a USB host like a computer causes FreeBSD
   to switch to device mode. Single purpose "client ports" always work in
   device mode.

   What FreeBSD presents to the USB host depends on the hw.usb.template
   sysctl. Some templates provide a single device, such as a serial terminal;
   others provide multiple ones, which can all be used at the same time. An
   example is the template 10, which provides a mass storage device, a serial
   console, and a network interface. See usb_template(4) for the list of
   available values.

   Note that in some cases, depending on the hardware and the hosts operating
   system, for the host to notice the configuration change, it must be either
   physically disconnected and reconnected, or forced to rescan the USB bus
   in a system-specific way. When FreeBSD is running on the host,
   usbconfig(8) reset can be used. This also must be done after loading
   usb_template.ko if the USB host was already connected to the USB OTG
   socket.

   After reading this chapter, you will know:

     * How to set up USB Device Mode functionality on FreeBSD.

     * How to configure the virtual serial port on FreeBSD.

     * How to connect to the virtual serial port from various operating
       systems.

     * How to configure FreeBSD to provide a virtual USB network interface.

     * How to configure FreeBSD to provide a virtual USB storage device.

26.2. USB Virtual Serial Ports

  26.2.1. Configuring USB Device Mode Serial Ports

   Virtual serial port support is provided by templates number 3, 8, and 10.
   Note that template 3 works with Microsoft Windows 10 without the need for
   special drivers and INF files. Other host operating systems work with all
   three templates. Both usb_template(4) and umodem(4) kernel modules must be
   loaded.

   To enable USB device mode serial ports, add those lines to /etc/ttys:

 ttyU0   "/usr/libexec/getty 3wire"      vt100   onifconsole secure
 ttyU1   "/usr/libexec/getty 3wire"      vt100   onifconsole secure

   Then add these lines to /etc/devd.conf:

 notify 100 {
         match "system"          "DEVFS";
         match "subsystem"       "CDEV";
         match "type"            "CREATE";
         match "cdev"            "ttyU[0-9]+";
         action "/sbin/init q";
 };

   Reload the configuration if devd(8) is already running:

 # service devd restart

   Make sure the necessary modules are loaded and the correct template is set
   at boot by adding those lines to /boot/loader.conf, creating it if it does
   not already exist:

 umodem_load="YES"
 hw.usb.template=3

   To load the module and set the template without rebooting use:

 # kldload umodem
 # sysctl hw.usb.template=3

  26.2.2. Connecting to USB Device Mode Serial Ports from FreeBSD

   To connect to a board configured to provide USB device mode serial ports,
   connect the USB host, such as a laptop, to the boards USB OTG or USB
   client port. Use pstat -t on the host to list the terminal lines. Near the
   end of the list you should see a USB serial port, eg "ttyU0". To open the
   connection, use:

 # cu -l /dev/ttyU0

   After pressing the Enter key a few times you will see a login prompt.

  26.2.3. Connecting to USB Device Mode Serial Ports from Mac OS(R)

   To connect to a board configured to provide USB device mode serial ports,
   connect the USB host, such as a laptop, to the boards USB OTG or USB
   client port. To open the connection, use:

 # cu -l /dev/cu.usbmodemFreeBSD1

  26.2.4. Connecting to USB Device Mode Serial Ports from Linux

   To connect to a board configured to provide USB device mode serial ports,
   connect the USB host, such as a laptop, to the boards USB OTG or USB
   client port. To open the connection, use:

 # minicom -D /dev/ttyACM0

  26.2.5. Connecting to USB Device Mode Serial Ports from Microsoft Windows 10

   To connect to a board configured to provide USB device mode serial ports,
   connect the USB host, such as a laptop, to the boards USB OTG or USB
   client port. To open a connection you will need a serial terminal program,
   such as PuTTY. To check the COM port name used by Windows, run Device
   Manager, expand "Ports (COM & LPT)". You will see a name similar to "USB
   Serial Device (COM4)". Run serial terminal program of your choice, for
   example PuTTY. In the PuTTY dialog set "Connection type" to "Serial", type
   the COMx obtained from Device Manager in the "Serial line" dialog box and
   click Open.

26.3. USB Device Mode Network Interfaces

   Virtual network interfaces support is provided by templates number 1, 8,
   and 10. Note that none of them works with Microsoft Windows. Other host
   operating systems work with all three templates. Both usb_template(4) and
   if_cdce(4) kernel modules must be loaded.

   Make sure the necessary modules are loaded and the correct template is set
   at boot by adding those lines to /boot/loader.conf, creating it if it does
   not already exist:

 if_cdce_load="YES"
 hw.usb.template=1

   To load the module and set the template without rebooting use:

 # kldload if_cdce
 # sysctl hw.usb.template=1

26.4. USB Virtual Storage Device

  Note:

   The cfumass(4) driver is a USB device mode driver first available in
   FreeBSD 12.0.

   Mass Storage target is provided by templates 0 and 10. Both
   usb_template(4) and cfumass(4) kernel modules must be loaded. cfumass(4)
   interfaces to the CTL subsystem, the same one that is used for iSCSI or
   Fibre Channel targets. On the host side, USB Mass Storage initiators can
   only access a single LUN, LUN 0.

  26.4.1. Configuring USB Mass Storage Target Using the cfumass Startup Script

   The simplest way to set up a read-only USB storage target is to use the
   cfumass rc script. To configure it this way, copy the files to be
   presented to the USB host machine into the /var/cfumass directory, and add
   this line to /etc/rc.conf:

 cfumass_enable="YES"

   To configure the target without restarting, run this command:

 # service cfumass start

   Differently from serial and network functionality, the template should not
   be set to 0 or 10 in /boot/loader.conf. This is because the LUN must be
   set up before setting the template. The cfumass startup script sets the
   correct template number automatically when started.

  26.4.2. Configuring USB Mass Storage Using Other Means

   The rest of this chapter provides detailed description of setting the
   target without using the cfumass rc file. This is necessary if eg one
   wants to provide a writeable LUN.

   USB Mass Storage does not require the ctld(8) daemon to be running,
   although it can be used if desired. This is different from iSCSI. Thus,
   there are two ways to configure the target: ctladm(8), or ctld(8). Both
   require the cfumass.ko kernel module to be loaded. The module can be
   loaded manually:

 # kldload cfumass

   If cfumass.ko has not been built into the kernel, /boot/loader.conf can be
   set to load the module at boot:

 cfumass_load="YES"

   A LUN can be created without the ctld(8) daemon:

 # ctladm create -b block -o file=/data/target0

   This presents the contents of the image file /data/target0 as a LUN to the
   USB host. The file must exist before executing the command. To configure
   the LUN at system startup, add the command to /etc/rc.local.

   ctld(8) can also be used to manage LUNs. Create /etc/ctl.conf, add a line
   to /etc/rc.conf to make sure ctld(8) is automatically started at boot, and
   then start the daemon.

   This is an example of a simple /etc/ctl.conf configuration file. Refer to
   ctl.conf(5) for a more complete description of the options.

 target naa.50015178f369f092 {
         lun 0 {
                 path /data/target0
                 size 4G
         }
 }

   The example creates a single target with a single LUN. The
   naa.50015178f369f092 is a device identifier composed of 32 random
   hexadecimal digits. The path line defines the full path to a file or zvol
   backing the LUN. That file must exist before starting ctld(8). The second
   line is optional and specifies the size of the LUN.

   To make sure the ctld(8) daemon is started at boot, add this line to
   /etc/rc.conf:

 ctld_enable="YES"

   To start ctld(8) now, run this command:

 # service ctld start

   As the ctld(8) daemon is started, it reads /etc/ctl.conf. If this file is
   edited after the daemon starts, reload the changes so they take effect
   immediately:

 # service ctld reload

                         Part IV. Network Communication

   FreeBSD is one of the most widely deployed operating systems for high
   performance network servers. The chapters in this part cover:

     * Serial communication

     * PPP and PPP over Ethernet

     * Electronic Mail

     * Running Network Servers

     * Firewalls

     * Other Advanced Networking Topics

   These chapters are designed to be read when the information is needed.
   They do not need to be read in any particular order, nor is it necessary
   to read all of them before using FreeBSD in a network environment.

   Table of Contents

   27. Serial Communications

                27.1. Synopsis

                27.2. Serial Terminology and Hardware

                27.3. Terminals

                27.4. Dial-in Service

                27.5. Dial-out Service

                27.6. Setting Up the Serial Console

   28. PPP

                28.1. Synopsis

                28.2. Configuring PPP

                28.3. Troubleshooting PPP Connections

                28.4. Using PPP over Ethernet (PPPoE)

                28.5. Using PPP over ATM (PPPoA)

   29. Electronic Mail

                29.1. Synopsis

                29.2. Mail Components

                29.3. Sendmail Configuration Files

                29.4. Changing the Mail Transfer Agent

                29.5. Troubleshooting

                29.6. Advanced Topics

                29.7. Setting Up to Send Only

                29.8. Using Mail with a Dialup Connection

                29.9. SMTP Authentication

                29.10. Mail User Agents

                29.11. Using fetchmail

                29.12. Using procmail

   30. Network Servers

                30.1. Synopsis

                30.2. The inetd Super-Server

                30.3. Network File System (NFS)

                30.4. Network Information System (NIS)

                30.5. Lightweight Directory Access Protocol (LDAP)

                30.6. Dynamic Host Configuration Protocol (DHCP)

                30.7. Domain Name System (DNS)

                30.8. Apache HTTP Server

                30.9. File Transfer Protocol (FTP)

                30.10. File and Print Services for Microsoft(R) Windows(R)
                Clients (Samba)

                30.11. Clock Synchronization with NTP

                30.12. iSCSI Initiator and Target Configuration

   31. Firewalls

                31.1. Synopsis

                31.2. Firewall Concepts

                31.3. PF

                31.4. IPFW

                31.5. IPFILTER (IPF)

                31.6. Blacklistd

   32. Advanced Networking

                32.1. Synopsis

                32.2. Gateways and Routes

                32.3. Wireless Networking

                32.4. USB Tethering

                32.5. Bluetooth

                32.6. Bridging

                32.7. Link Aggregation and Failover

                32.8. Diskless Operation with PXE

                32.9. IPv6

                32.10. Common Address Redundancy Protocol (CARP)

                32.11. VLANs

Chapter 27. Serial Communications

   Table of Contents

   27.1. Synopsis

   27.2. Serial Terminology and Hardware

   27.3. Terminals

   27.4. Dial-in Service

   27.5. Dial-out Service

   27.6. Setting Up the Serial Console

27.1. Synopsis

   UNIX(R) has always had support for serial communications as the very first
   UNIX(R) machines relied on serial lines for user input and output. Things
   have changed a lot from the days when the average terminal consisted of a
   10-character-per-second serial printer and a keyboard. This chapter covers
   some of the ways serial communications can be used on FreeBSD.

   After reading this chapter, you will know:

     * How to connect terminals to a FreeBSD system.

     * How to use a modem to dial out to remote hosts.

     * How to allow remote users to login to a FreeBSD system with a modem.

     * How to boot a FreeBSD system from a serial console.

   Before reading this chapter, you should:

     * Know how to configure and install a custom kernel.

     * Understand FreeBSD permissions and processes.

     * Have access to the technical manual for the serial hardware to be used
       with FreeBSD.

27.2. Serial Terminology and Hardware

   The following terms are often used in serial communications:

   bps

           Bits per Second (bps) is the rate at which data is transmitted.

   DTE

           Data Terminal Equipment (DTE) is one of two endpoints in a serial
           communication. An example would be a computer.

   DCE

           Data Communications Equipment (DTE) is the other endpoint in a
           serial communication. Typically, it is a modem or serial terminal.

   RS-232

           The original standard which defined hardware serial
           communications. It has since been renamed to TIA-232.

   When referring to communication data rates, this section does not use the
   term baud. Baud refers to the number of electrical state transitions made
   in a period of time, while bps is the correct term to use.

   To connect a serial terminal to a FreeBSD system, a serial port on the
   computer and the proper cable to connect to the serial device are needed.
   Users who are already familiar with serial hardware and cabling can safely
   skip this section.

  27.2.1. Serial Cables and Ports

   There are several different kinds of serial cables. The two most common
   types are null-modem cables and standard RS-232 cables. The documentation
   for the hardware should describe the type of cable required.

   These two types of cables differ in how the wires are connected to the
   connector. Each wire represents a signal, with the defined signals
   summarized in Table 27.1, "RS-232C Signal Names". A standard serial cable
   passes all of the RS-232C signals straight through. For example, the
   "Transmitted Data" pin on one end of the cable goes to the "Transmitted
   Data" pin on the other end. This is the type of cable used to connect a
   modem to the FreeBSD system, and is also appropriate for some terminals.

   A null-modem cable switches the "Transmitted Data" pin of the connector on
   one end with the "Received Data" pin on the other end. The connector can
   be either a DB-25 or a DB-9.

   A null-modem cable can be constructed using the pin connections summarized
   in Table 27.2, "DB-25 to DB-25 Null-Modem Cable", Table 27.3, "DB-9 to
   DB-9 Null-Modem Cable", and Table 27.4, "DB-9 to DB-25 Null-Modem Cable".
   While the standard calls for a straight-through pin 1 to pin 1 "Protective
   Ground" line, it is often omitted. Some terminals work using only pins 2,
   3, and 7, while others require different configurations. When in doubt,
   refer to the documentation for the hardware.

   Table 27.1. RS-232C Signal Names

   Acronyms                        Names                                      
   RD                              Received Data                              
   TD                              Transmitted Data                           
   DTR                             Data Terminal Ready                        
   DSR                             Data Set Ready                             
   DCD                             Data Carrier Detect                        
   SG                              Signal Ground                              
   RTS                             Request to Send                            
   CTS                             Clear to Send                              

   Table 27.2. DB-25 to DB-25 Null-Modem Cable

   Signal         Pin #                            Pin #        Signal        
   SG             7             connects to        7            SG            
   TD             2             connects to        3            RD            
   RD             3             connects to        2            TD            
   RTS            4             connects to        5            CTS           
   CTS            5             connects to        4            RTS           
   DTR            20            connects to        6            DSR           
   DTR            20            connects to        8            DCD           
   DSR            6             connects to        20           DTR           
   DCD            8             connects to        20           DTR           

   Table 27.3. DB-9 to DB-9 Null-Modem Cable

   Signal         Pin #                            Pin #        Signal        
   RD             2             connects to        3            TD            
   TD             3             connects to        2            RD            
   DTR            4             connects to        6            DSR           
   DTR            4             connects to        1            DCD           
   SG             5             connects to        5            SG            
   DSR            6             connects to        4            DTR           
   DCD            1             connects to        4            DTR           
   RTS            7             connects to        8            CTS           
   CTS            8             connects to        7            RTS           

   Table 27.4. DB-9 to DB-25 Null-Modem Cable

   Signal         Pin #                            Pin #        Signal        
   RD             2             connects to        2            TD            
   TD             3             connects to        3            RD            
   DTR            4             connects to        6            DSR           
   DTR            4             connects to        8            DCD           
   SG             5             connects to        7            SG            
   DSR            6             connects to        20           DTR           
   DCD            1             connects to        20           DTR           
   RTS            7             connects to        5            CTS           
   CTS            8             connects to        4            RTS           

  Note:

   When one pin at one end connects to a pair of pins at the other end, it is
   usually implemented with one short wire between the pair of pins in their
   connector and a long wire to the other single pin.

   Serial ports are the devices through which data is transferred between the
   FreeBSD host computer and the terminal. Several kinds of serial ports
   exist. Before purchasing or constructing a cable, make sure it will fit
   the ports on the terminal and on the FreeBSD system.

   Most terminals have DB-25 ports. Personal computers may have DB-25 or DB-9
   ports. A multiport serial card may have RJ-12 or RJ-45/ ports. See the
   documentation that accompanied the hardware for specifications on the kind
   of port or visually verify the type of port.

   In FreeBSD, each serial port is accessed through an entry in /dev. There
   are two different kinds of entries:

     * Call-in ports are named /dev/ttyuN where N is the port number,
       starting from zero. If a terminal is connected to the first serial
       port (COM1), use /dev/ttyu0 to refer to the terminal. If the terminal
       is on the second serial port (COM2), use /dev/ttyu1, and so forth.
       Generally, the call-in port is used for terminals. Call-in ports
       require that the serial line assert the "Data Carrier Detect" signal
       to work correctly.

     * Call-out ports are named /dev/cuauN on FreeBSD versions 8.X and higher
       and /dev/cuadN on FreeBSD versions 7.X and lower. Call-out ports are
       usually not used for terminals, but are used for modems. The call-out
       port can be used if the serial cable or the terminal does not support
       the "Data Carrier Detect" signal.

   FreeBSD also provides initialization devices (/dev/ttyuN.init and
   /dev/cuauN.init or /dev/cuadN.init) and locking devices (/dev/ttyuN.lock
   and /dev/cuauN.lock or /dev/cuadN.lock). The initialization devices are
   used to initialize communications port parameters each time a port is
   opened, such as crtscts for modems which use RTS/CTS signaling for flow
   control. The locking devices are used to lock flags on ports to prevent
   users or programs changing certain parameters. Refer to termios(4),
   sio(4), and stty(1) for information on terminal settings, locking and
   initializing devices, and setting terminal options, respectively.

  27.2.2. Serial Port Configuration

   By default, FreeBSD supports four serial ports which are commonly known as
   COM1, COM2, COM3, and COM4. FreeBSD also supports dumb multi-port serial
   interface cards, such as the BocaBoard 1008 and 2016, as well as more
   intelligent multi-port cards such as those made by Digiboard. However, the
   default kernel only looks for the standard COM ports.

   To see if the system recognizes the serial ports, look for system boot
   messages that start with uart:

 # grep uart /var/run/dmesg.boot

   If the system does not recognize all of the needed serial ports,
   additional entries can be added to /boot/device.hints. This file already
   contains hint.uart.0.* entries for COM1 and hint.uart.1.* entries for
   COM2. When adding a port entry for COM3 use 0x3E8, and for COM4 use 0x2E8.
   Common IRQ addresses are 5 for COM3 and 9 for COM4.

   To determine the default set of terminal I/O settings used by the port,
   specify its device name. This example determines the settings for the
   call-in port on COM2:

 # stty -a -f /dev/ttyu1

   System-wide initialization of serial devices is controlled by
   /etc/rc.d/serial. This file affects the default settings of serial
   devices. To change the settings for a device, use stty. By default, the
   changed settings are in effect until the device is closed and when the
   device is reopened, it goes back to the default set. To permanently change
   the default set, open and adjust the settings of the initialization
   device. For example, to turn on CLOCAL mode, 8 bit communication, and
   XON/XOFF flow control for ttyu5, type:

 # stty -f /dev/ttyu5.init clocal cs8 ixon ixoff

   To prevent certain settings from being changed by an application, make
   adjustments to the locking device. For example, to lock the speed of ttyu5
   to 57600 bps, type:

 # stty -f /dev/ttyu5.lock 57600

   Now, any application that opens ttyu5 and tries to change the speed of the
   port will be stuck with 57600 bps.

27.3. Terminals

   Contributed by Sean Kelly.

   Terminals provide a convenient and low-cost way to access a FreeBSD system
   when not at the computer's console or on a connected network. This section
   describes how to use terminals with FreeBSD.

   The original UNIX(R) systems did not have consoles. Instead, users logged
   in and ran programs through terminals that were connected to the
   computer's serial ports.

   The ability to establish a login session on a serial port still exists in
   nearly every UNIX(R)-like operating system today, including FreeBSD. By
   using a terminal attached to an unused serial port, a user can log in and
   run any text program that can normally be run on the console or in an
   xterm window.

   Many terminals can be attached to a FreeBSD system. An older spare
   computer can be used as a terminal wired into a more powerful computer
   running FreeBSD. This can turn what might otherwise be a single-user
   computer into a powerful multiple-user system.

   FreeBSD supports three types of terminals:

   Dumb terminals

           Dumb terminals are specialized hardware that connect to computers
           over serial lines. They are called "dumb" because they have only
           enough computational power to display, send, and receive text. No
           programs can be run on these devices. Instead, dumb terminals
           connect to a computer that runs the needed programs.

           There are hundreds of kinds of dumb terminals made by many
           manufacturers, and just about any kind will work with FreeBSD.
           Some high-end terminals can even display graphics, but only
           certain software packages can take advantage of these advanced
           features.

           Dumb terminals are popular in work environments where workers do
           not need access to graphical applications.

   Computers Acting as Terminals

           Since a dumb terminal has just enough ability to display, send,
           and receive text, any spare computer can be a dumb terminal. All
           that is needed is the proper cable and some terminal emulation
           software to run on the computer.

           This configuration can be useful. For example, if one user is busy
           working at the FreeBSD system's console, another user can do some
           text-only work at the same time from a less powerful personal
           computer hooked up as a terminal to the FreeBSD system.

           There are at least two utilities in the base-system of FreeBSD
           that can be used to work through a serial connection: cu(1) and
           tip(1).

           For example, to connect from a client system that runs FreeBSD to
           the serial connection of another system:

 # cu -l /dev/cuauN

           Ports are numbered starting from zero. This means that COM1 is
           /dev/cuau0.

           Additional programs are available through the Ports Collection,
           such as comms/minicom.

   X Terminals

           X terminals are the most sophisticated kind of terminal available.
           Instead of connecting to a serial port, they usually connect to a
           network like Ethernet. Instead of being relegated to text-only
           applications, they can display any Xorg application.

           This chapter does not cover the setup, configuration, or use of X
           terminals.

  27.3.1. Terminal Configuration

   This section describes how to configure a FreeBSD system to enable a login
   session on a serial terminal. It assumes that the system recognizes the
   serial port to which the terminal is connected and that the terminal is
   connected with the correct cable.

   In FreeBSD, init reads /etc/ttys and starts a getty process on the
   available terminals. The getty process is responsible for reading a login
   name and starting the login program. The ports on the FreeBSD system which
   allow logins are listed in /etc/ttys. For example, the first virtual
   console, ttyv0, has an entry in this file, allowing logins on the console.
   This file also contains entries for the other virtual consoles, serial
   ports, and pseudo-ttys. For a hardwired terminal, the serial port's /dev
   entry is listed without the /dev part. For example, /dev/ttyv0 is listed
   as ttyv0.

   The default /etc/ttys configures support for the first four serial ports,
   ttyu0 through ttyu3:

 ttyu0   "/usr/libexec/getty std.9600"   dialup  off secure
 ttyu1   "/usr/libexec/getty std.9600"   dialup  off secure
 ttyu2   "/usr/libexec/getty std.9600"   dialup  off secure
 ttyu3   "/usr/libexec/getty std.9600"   dialup  off secure

   When attaching a terminal to one of those ports, modify the default entry
   to set the required speed and terminal type, to turn the device on and, if
   needed, to change the port's secure setting. If the terminal is connected
   to another port, add an entry for the port.

   Example 27.1, "Configuring Terminal Entries" configures two terminals in
   /etc/ttys. The first entry configures a Wyse-50 connected to COM2. The
   second entry configures an old computer running Procomm terminal software
   emulating a VT-100 terminal. The computer is connected to the sixth serial
   port on a multi-port serial card.

   Example 27.1. Configuring Terminal Entries

 ttyu11  "/usr/libexec/getty std.38400"2  wy503  on4  insecure5
 ttyu5   "/usr/libexec/getty std.19200"  vt100  on insecure

   1 The first field specifies the device name of the serial terminal.        
   2 The second field tells getty to initialize and open the line, set the    
     line speed, prompt for a user name, and then execute the login program.  
     The optional getty type configures characteristics on the terminal line, 
     like bps rate and parity. The available getty types are listed in        
     /etc/gettytab. In almost all cases, the getty types that start with std  
     will work for hardwired terminals as these entries ignore parity. There  
     is a std entry for each bps rate from 110 to 115200. Refer to            
     gettytab(5) for more information.                                        
                                                                              
     When setting the getty type, make sure to match the communications       
     settings used by the terminal. For this example, the Wyse-50 uses no     
     parity and connects at 38400 bps. The computer uses no parity and        
     connects at 19200 bps.                                                   
   3 The third field is the type of terminal. For dial-up ports, unknown or   
     dialup is typically used since users may dial up with practically any    
     type of terminal or software. Since the terminal type does not change    
     for hardwired terminals, a real terminal type from /etc/termcap can be   
     specified. For this example, the Wyse-50 uses the real terminal type     
     while the computer running Procomm is set to emulate a VT-100.           
   4 The fourth field specifies if the port should be enabled. To enable      
     logins on this port, this field must be set to on.                       
   5 The final field is used to specify whether the port is secure. Marking a 
     port as secure means that it is trusted enough to allow root to login    
     from that port. Insecure ports do not allow root logins. On an insecure  
     port, users must login from unprivileged accounts and then use su or a   
     similar mechanism to gain superuser privileges, as described in          
     Section 3.3.1.3, "The Superuser Account". For security reasons, it is    
     recommended to change this setting to insecure.                          

   After making any changes to /etc/ttys, send a SIGHUP (hangup) signal to
   the init process to force it to re-read its configuration file:

 # kill -HUP 1

   Since init is always the first process run on a system, it always has a
   process ID of 1.

   If everything is set up correctly, all cables are in place, and the
   terminals are powered up, a getty process should now be running on each
   terminal and login prompts should be available on each terminal.

  27.3.2. Troubleshooting the Connection

   Even with the most meticulous attention to detail, something could still
   go wrong while setting up a terminal. Here is a list of common symptoms
   and some suggested fixes.

   If no login prompt appears, make sure the terminal is plugged in and
   powered up. If it is a personal computer acting as a terminal, make sure
   it is running terminal emulation software on the correct serial port.

   Make sure the cable is connected firmly to both the terminal and the
   FreeBSD computer. Make sure it is the right kind of cable.

   Make sure the terminal and FreeBSD agree on the bps rate and parity
   settings. For a video display terminal, make sure the contrast and
   brightness controls are turned up. If it is a printing terminal, make sure
   paper and ink are in good supply.

   Use ps to make sure that a getty process is running and serving the
   terminal. For example, the following listing shows that a getty is running
   on the second serial port, ttyu1, and is using the std.38400 entry in
   /etc/gettytab:

 # ps -axww|grep ttyu
 22189  d1  Is+    0:00.03 /usr/libexec/getty std.38400 ttyu1

   If no getty process is running, make sure the port is enabled in
   /etc/ttys. Remember to run kill -HUP 1 after modifying /etc/ttys.

   If the getty process is running but the terminal still does not display a
   login prompt, or if it displays a prompt but will not accept typed input,
   the terminal or cable may not support hardware handshaking. Try changing
   the entry in /etc/ttys from std.38400 to 3wire.38400, then run kill -HUP 1
   after modifying /etc/ttys. The 3wire entry is similar to std, but ignores
   hardware handshaking. The baud rate may need to be reduced or software
   flow control enabled when using 3wire to prevent buffer overflows.

   If garbage appears instead of a login prompt, make sure the terminal and
   FreeBSD agree on the bps rate and parity settings. Check the getty
   processes to make sure the correct getty type is in use. If not, edit
   /etc/ttys and run kill -HUP 1.

   If characters appear doubled and the password appears when typed, switch
   the terminal, or the terminal emulation software, from "half duplex" or
   "local echo" to "full duplex."

27.4. Dial-in Service

   Contributed by Guy Helmer.
   Additions by Sean Kelly.

   Configuring a FreeBSD system for dial-in service is similar to configuring
   terminals, except that modems are used instead of terminal devices.
   FreeBSD supports both external and internal modems.

   External modems are more convenient because they often can be configured
   via parameters stored in non-volatile RAM and they usually provide lighted
   indicators that display the state of important RS-232 signals, indicating
   whether the modem is operating properly.

   Internal modems usually lack non-volatile RAM, so their configuration may
   be limited to setting DIP switches. If the internal modem has any signal
   indicator lights, they are difficult to view when the system's cover is in
   place.

   When using an external modem, a proper cable is needed. A standard RS-232C
   serial cable should suffice.

   FreeBSD needs the RTS and CTS signals for flow control at speeds above
   2400 bps, the CD signal to detect when a call has been answered or the
   line has been hung up, and the DTR signal to reset the modem after a
   session is complete. Some cables are wired without all of the needed
   signals, so if a login session does not go away when the line hangs up,
   there may be a problem with the cable. Refer to Section 27.2.1, "Serial
   Cables and Ports" for more information about these signals.

   Like other UNIX(R)-like operating systems, FreeBSD uses the hardware
   signals to find out when a call has been answered or a line has been hung
   up and to hangup and reset the modem after a call. FreeBSD avoids sending
   commands to the modem or watching for status reports from the modem.

   FreeBSD supports the NS8250, NS16450, NS16550, and NS16550A-based RS-232C
   (CCITT V.24) communications interfaces. The 8250 and 16450 devices have
   single-character buffers. The 16550 device provides a 16-character buffer,
   which allows for better system performance. Bugs in plain 16550 devices
   prevent the use of the 16-character buffer, so use 16550A devices if
   possible. As single-character-buffer devices require more work by the
   operating system than the 16-character-buffer devices, 16550A-based serial
   interface cards are preferred. If the system has many active serial ports
   or will have a heavy load, 16550A-based cards are better for
   low-error-rate communications.

   The rest of this section demonstrates how to configure a modem to receive
   incoming connections, how to communicate with the modem, and offers some
   troubleshooting tips.

  27.4.1. Modem Configuration

   As with terminals, init spawns a getty process for each configured serial
   port used for dial-in connections. When a user dials the modem's line and
   the modems connect, the "Carrier Detect" signal is reported by the modem.
   The kernel notices that the carrier has been detected and instructs getty
   to open the port and display a login: prompt at the specified initial line
   speed. In a typical configuration, if garbage characters are received,
   usually due to the modem's connection speed being different than the
   configured speed, getty tries adjusting the line speeds until it receives
   reasonable characters. After the user enters their login name, getty
   executes login, which completes the login process by asking for the user's
   password and then starting the user's shell.

   There are two schools of thought regarding dial-up modems. One
   configuration method is to set the modems and systems so that no matter at
   what speed a remote user dials in, the dial-in RS-232 interface runs at a
   locked speed. The benefit of this configuration is that the remote user
   always sees a system login prompt immediately. The downside is that the
   system does not know what a user's true data rate is, so full-screen
   programs like Emacs will not adjust their screen-painting methods to make
   their response better for slower connections.

   The second method is to configure the RS-232 interface to vary its speed
   based on the remote user's connection speed. As getty does not understand
   any particular modem's connection speed reporting, it gives a login:
   message at an initial speed and watches the characters that come back in
   response. If the user sees junk, they should press Enter until they see a
   recognizable prompt. If the data rates do not match, getty sees anything
   the user types as junk, tries the next speed, and gives the login: prompt
   again. This procedure normally only takes a keystroke or two before the
   user sees a good prompt. This login sequence does not look as clean as the
   locked-speed method, but a user on a low-speed connection should receive
   better interactive response from full-screen programs.

   When locking a modem's data communications rate at a particular speed, no
   changes to /etc/gettytab should be needed. However, for a matching-speed
   configuration, additional entries may be required in order to define the
   speeds to use for the modem. This example configures a 14.4 Kbps modem
   with a top interface speed of 19.2 Kbps using 8-bit, no parity
   connections. It configures getty to start the communications rate for a
   V.32bis connection at 19.2 Kbps, then cycles through 9600 bps, 2400 bps,
   1200 bps, 300 bps, and back to 19.2 Kbps. Communications rate cycling is
   implemented with the nx= (next table) capability. Each line uses a tc=
   (table continuation) entry to pick up the rest of the settings for a
   particular data rate.

 #
 # Additions for a V.32bis Modem
 #
 um|V300|High Speed Modem at 300,8-bit:\
         :nx=V19200:tc=std.300:
 un|V1200|High Speed Modem at 1200,8-bit:\
         :nx=V300:tc=std.1200:
 uo|V2400|High Speed Modem at 2400,8-bit:\
         :nx=V1200:tc=std.2400:
 up|V9600|High Speed Modem at 9600,8-bit:\
         :nx=V2400:tc=std.9600:
 uq|V19200|High Speed Modem at 19200,8-bit:\
         :nx=V9600:tc=std.19200:

   For a 28.8 Kbps modem, or to take advantage of compression on a 14.4 Kbps
   modem, use a higher communications rate, as seen in this example:

 #
 # Additions for a V.32bis or V.34 Modem
 # Starting at 57.6 Kbps
 #
 vm|VH300|Very High Speed Modem at 300,8-bit:\
         :nx=VH57600:tc=std.300:
 vn|VH1200|Very High Speed Modem at 1200,8-bit:\
         :nx=VH300:tc=std.1200:
 vo|VH2400|Very High Speed Modem at 2400,8-bit:\
         :nx=VH1200:tc=std.2400:
 vp|VH9600|Very High Speed Modem at 9600,8-bit:\
         :nx=VH2400:tc=std.9600:
 vq|VH57600|Very High Speed Modem at 57600,8-bit:\
         :nx=VH9600:tc=std.57600:

   For a slow CPU or a heavily loaded system without 16550A-based serial
   ports, this configuration may produce sio "silo" errors at 57.6 Kbps.

   The configuration of /etc/ttys is similar to Example 27.1, "Configuring
   Terminal Entries", but a different argument is passed to getty and dialup
   is used for the terminal type. Replace xxx with the process init will run
   on the device:

 ttyu0   "/usr/libexec/getty xxx"   dialup on

   The dialup terminal type can be changed. For example, setting vt102 as the
   default terminal type allows users to use VT102 emulation on their remote
   systems.

   For a locked-speed configuration, specify the speed with a valid type
   listed in /etc/gettytab. This example is for a modem whose port speed is
   locked at 19.2 Kbps:

 ttyu0   "/usr/libexec/getty std.19200"   dialup on

   In a matching-speed configuration, the entry needs to reference the
   appropriate beginning "auto-baud" entry in /etc/gettytab. To continue the
   example for a matching-speed modem that starts at 19.2 Kbps, use this
   entry:

 ttyu0   "/usr/libexec/getty V19200"   dialup on

   After editing /etc/ttys, wait until the modem is properly configured and
   connected before signaling init:

 # kill -HUP 1

   High-speed modems, like V.32, V.32bis, and V.34 modems, use hardware
   (RTS/CTS) flow control. Use stty to set the hardware flow control flag for
   the modem port. This example sets the crtscts flag on COM2's dial-in and
   dial-out initialization devices:

 # stty -f /dev/ttyu1.init crtscts
 # stty -f /dev/cuau1.init crtscts

  27.4.2. Troubleshooting

   This section provides a few tips for troubleshooting a dial-up modem that
   will not connect to a FreeBSD system.

   Hook up the modem to the FreeBSD system and boot the system. If the modem
   has status indication lights, watch to see whether the modem's DTR
   indicator lights when the login: prompt appears on the system's console.
   If it lights up, that should mean that FreeBSD has started a getty process
   on the appropriate communications port and is waiting for the modem to
   accept a call.

   If the DTR indicator does not light, login to the FreeBSD system through
   the console and type ps ax to see if FreeBSD is running a getty process on
   the correct port:

   114 ??  I      0:00.10 /usr/libexec/getty V19200 ttyu0

   If the second column contains a d0 instead of a ?? and the modem has not
   accepted a call yet, this means that getty has completed its open on the
   communications port. This could indicate a problem with the cabling or a
   misconfigured modem because getty should not be able to open the
   communications port until the carrier detect signal has been asserted by
   the modem.

   If no getty processes are waiting to open the port, double-check that the
   entry for the port is correct in /etc/ttys. Also, check /var/log/messages
   to see if there are any log messages from init or getty.

   Next, try dialing into the system. Be sure to use 8 bits, no parity, and 1
   stop bit on the remote system. If a prompt does not appear right away, or
   the prompt shows garbage, try pressing Enter about once per second. If
   there is still no login: prompt, try sending a BREAK. When using a
   high-speed modem, try dialing again after locking the dialing modem's
   interface speed.

   If there is still no login: prompt, check /etc/gettytab again and
   double-check that:

     * The initial capability name specified in the entry in /etc/ttys
       matches the name of a capability in /etc/gettytab.

     * Each nx= entry matches another gettytab capability name.

     * Each tc= entry matches another gettytab capability name.

   If the modem on the FreeBSD system will not answer, make sure that the
   modem is configured to answer the phone when DTR is asserted. If the modem
   seems to be configured correctly, verify that the DTR line is asserted by
   checking the modem's indicator lights.

   If it still does not work, try sending an email to the FreeBSD general
   questions mailing list describing the modem and the problem.

27.5. Dial-out Service

   The following are tips for getting the host to connect over the modem to
   another computer. This is appropriate for establishing a terminal session
   with a remote host.

   This kind of connection can be helpful to get a file on the Internet if
   there are problems using PPP. If PPP is not working, use the terminal
   session to FTP the needed file. Then use zmodem to transfer it to the
   machine.

  27.5.1. Using a Stock Hayes Modem

   A generic Hayes dialer is built into tip. Use at=hayes in /etc/remote.

   The Hayes driver is not smart enough to recognize some of the advanced
   features of newer modems messages like BUSY, NO DIALTONE, or CONNECT
   115200. Turn those messages off when using tip with ATX0&W.

   The dial timeout for tip is 60 seconds. The modem should use something
   less, or else tip will think there is a communication problem. Try
   ATS7=45&W.

  27.5.2. Using AT Commands

   Create a "direct" entry in /etc/remote. For example, if the modem is
   hooked up to the first serial port, /dev/cuau0, use the following line:

 cuau0:dv=/dev/cuau0:br#19200:pa=none

   Use the highest bps rate the modem supports in the br capability. Then,
   type tip cuau0 to connect to the modem.

   Or, use cu as root with the following command:

 # cu -lline -sspeed

   line is the serial port, such as /dev/cuau0, and speed is the speed, such
   as 57600. When finished entering the AT commands, type ~. to exit.

  27.5.3. The @ Sign Does Not Work

   The @ sign in the phone number capability tells tip to look in /etc/phones
   for a phone number. But, the @ sign is also a special character in
   capability files like /etc/remote, so it needs to be escaped with a
   backslash:

 pn=\@

  27.5.4. Dialing from the Command Line

   Put a "generic" entry in /etc/remote. For example:

 tip115200|Dial any phone number at 115200 bps:\
         :dv=/dev/cuau0:br#115200:at=hayes:pa=none:du:
 tip57600|Dial any phone number at 57600 bps:\
         :dv=/dev/cuau0:br#57600:at=hayes:pa=none:du:

   This should now work:

 # tip -115200 5551234

   Users who prefer cu over tip, can use a generic cu entry:

 cu115200|Use cu to dial any number at 115200bps:\
         :dv=/dev/cuau1:br#57600:at=hayes:pa=none:du:

   and type:

 # cu 5551234 -s 115200

  27.5.5. Setting the bps Rate

   Put in an entry for tip1200 or cu1200, but go ahead and use whatever bps
   rate is appropriate with the br capability. tip thinks a good default is
   1200 bps which is why it looks for a tip1200 entry. 1200 bps does not have
   to be used, though.

  27.5.6. Accessing a Number of Hosts Through a Terminal Server

   Rather than waiting until connected and typing CONNECT host each time, use
   tip's cm capability. For example, these entries in /etc/remote will let
   you type tip pain or tip muffin to connect to the hosts pain or muffin,
   and tip deep13 to connect to the terminal server.

 pain|pain.deep13.com|Forrester's machine:\
         :cm=CONNECT pain\n:tc=deep13:
 muffin|muffin.deep13.com|Frank's machine:\
         :cm=CONNECT muffin\n:tc=deep13:
 deep13:Gizmonics Institute terminal server:\
         :dv=/dev/cuau2:br#38400:at=hayes:du:pa=none:pn=5551234:

  27.5.7. Using More Than One Line with tip

   This is often a problem where a university has several modem lines and
   several thousand students trying to use them.

   Make an entry in /etc/remote and use @ for the pn capability:

 big-university:\
         :pn=\@:tc=dialout
 dialout:\
         :dv=/dev/cuau3:br#9600:at=courier:du:pa=none:

   Then, list the phone numbers in /etc/phones:

 big-university 5551111
 big-university 5551112
 big-university 5551113
 big-university 5551114

   tip will try each number in the listed order, then give up. To keep
   retrying, run tip in a while loop.

  27.5.8. Using the Force Character

   Ctrl+P is the default "force" character, used to tell tip that the next
   character is literal data. The force character can be set to any other
   character with the ~s escape, which means "set a variable."

   Type ~sforce=single-char followed by a newline. single-char is any single
   character. If single-char is left out, then the force character is the
   null character, which is accessed by typing Ctrl+2 or Ctrl+Space. A pretty
   good value for single-char is Shift+Ctrl+6, which is only used on some
   terminal servers.

   To change the force character, specify the following in ~/.tiprc:

 force=single-char

  27.5.9. Upper Case Characters

   This happens when Ctrl+A is pressed, which is tip's "raise character",
   specially designed for people with broken caps-lock keys. Use ~s to set
   raisechar to something reasonable. It can be set to be the same as the
   force character, if neither feature is used.

   Here is a sample ~/.tiprc for Emacs users who need to type Ctrl+2 and
   Ctrl+A:

 force=^^
 raisechar=^^

   The ^^ is Shift+Ctrl+6.

  27.5.10. File Transfers with tip

   When talking to another UNIX(R)-like operating system, files can be sent
   and received using ~p (put) and ~t (take). These commands run cat and echo
   on the remote system to accept and send files. The syntax is:

   ~p local-file [remote-file]

   ~t remote-file [local-file]

   There is no error checking, so another protocol, like zmodem, should
   probably be used.

  27.5.11. Using zmodem with tip?

   To receive files, start the sending program on the remote end. Then, type
   ~C rz to begin receiving them locally.

   To send files, start the receiving program on the remote end. Then, type
   ~C sz files to send them to the remote system.

27.6. Setting Up the Serial Console

   Contributed by Kazutaka YOKOTA.
   Based on a document by Bill Paul.

   FreeBSD has the ability to boot a system with a dumb terminal on a serial
   port as a console. This configuration is useful for system administrators
   who wish to install FreeBSD on machines that have no keyboard or monitor
   attached, and developers who want to debug the kernel or device drivers.

   As described in Chapter 13, The FreeBSD Booting Process, FreeBSD employs a
   three stage bootstrap. The first two stages are in the boot block code
   which is stored at the beginning of the FreeBSD slice on the boot disk.
   The boot block then loads and runs the boot loader as the third stage
   code.

   In order to set up booting from a serial console, the boot block code, the
   boot loader code, and the kernel need to be configured.

  27.6.1. Quick Serial Console Configuration

   This section provides a fast overview of setting up the serial console.
   This procedure can be used when the dumb terminal is connected to COM1.

   Procedure 27.1. Configuring a Serial Console on COM1
    1. Connect the serial cable to COM1 and the controlling terminal.

    2. To configure boot messages to display on the serial console, issue the
       following command as the superuser:

 # echo 'console="comconsole"' >> /boot/loader.conf

    3. Edit /etc/ttys and change off to on and dialup to vt100 for the ttyu0
       entry. Otherwise, a password will not be required to connect via the
       serial console, resulting in a potential security hole.

    4. Reboot the system to see if the changes took effect.

   If a different configuration is required, see the next section for a more
   in-depth configuration explanation.

  27.6.2. In-Depth Serial Console Configuration

   This section provides a more detailed explanation of the steps needed to
   setup a serial console in FreeBSD.

   Procedure 27.2. Configuring a Serial Console
    1. Prepare a serial cable.

       Use either a null-modem cable or a standard serial cable and a
       null-modem adapter. See Section 27.2.1, "Serial Cables and Ports" for
       a discussion on serial cables.

    2. Unplug the keyboard.

       Many systems probe for the keyboard during the Power-On Self-Test
       (POST) and will generate an error if the keyboard is not detected.
       Some machines will refuse to boot until the keyboard is plugged in.

       If the computer complains about the error, but boots anyway, no
       further configuration is needed.

       If the computer refuses to boot without a keyboard attached, configure
       the BIOS so that it ignores this error. Consult the motherboard's
       manual for details on how to do this.

  Tip:

       Try setting the keyboard to "Not installed" in the BIOS. This setting
       tells the BIOS not to probe for a keyboard at power-on so it should
       not complain if the keyboard is absent. If that option is not present
       in the BIOS, look for an "Halt on Error" option instead. Setting this
       to "All but Keyboard" or to "No Errors" will have the same effect.

       If the system has a PS/2(R) mouse, unplug it as well. PS/2(R) mice
       share some hardware with the keyboard and leaving the mouse plugged in
       can fool the keyboard probe into thinking the keyboard is still there.

  Note:

       While most systems will boot without a keyboard, quite a few will not
       boot without a graphics adapter. Some systems can be configured to
       boot with no graphics adapter by changing the "graphics adapter"
       setting in the BIOS configuration to "Not installed". Other systems do
       not support this option and will refuse to boot if there is no display
       hardware in the system. With these machines, leave some kind of
       graphics card plugged in, even if it is just a junky mono board. A
       monitor does not need to be attached.

    3. Plug a dumb terminal, an old computer with a modem program, or the
       serial port on another UNIX(R) box into the serial port.

    4. Add the appropriate hint.sio.* entries to /boot/device.hints for the
       serial port. Some multi-port cards also require kernel configuration
       options. Refer to sio(4) for the required options and device hints for
       each supported serial port.

    5. Create boot.config in the root directory of the a partition on the
       boot drive.

       This file instructs the boot block code how to boot the system. In
       order to activate the serial console, one or more of the following
       options are needed. When using multiple options, include them all on
       the same line:

            -h

                    Toggles between the internal and serial consoles. Use
                    this to switch console devices. For instance, to boot
                    from the internal (video) console, use -h to direct the
                    boot loader and the kernel to use the serial port as its
                    console device. Alternatively, to boot from the serial
                    port, use -h to tell the boot loader and the kernel to
                    use the video display as the console instead.

            -D

                    Toggles between the single and dual console
                    configurations. In the single configuration, the console
                    will be either the internal console (video display) or
                    the serial port, depending on the state of -h. In the
                    dual console configuration, both the video display and
                    the serial port will become the console at the same time,
                    regardless of the state of -h. However, the dual console
                    configuration takes effect only while the boot block is
                    running. Once the boot loader gets control, the console
                    specified by -h becomes the only console.

            -P

                    Makes the boot block probe the keyboard. If no keyboard
                    is found, the -D and -h options are automatically set.

  Note:

                    Due to space constraints in the current version of the
                    boot blocks, -P is capable of detecting extended
                    keyboards only. Keyboards with less than 101 keys and
                    without F11 and F12 keys may not be detected. Keyboards
                    on some laptops may not be properly found because of this
                    limitation. If this is the case, do not use -P.

       Use either -P to select the console automatically or -h to activate
       the serial console. Refer to boot(8) and boot.config(5) for more
       details.

       The options, except for -P, are passed to the boot loader. The boot
       loader will determine whether the internal video or the serial port
       should become the console by examining the state of -h. This means
       that if -D is specified but -h is not specified in /boot.config, the
       serial port can be used as the console only during the boot block as
       the boot loader will use the internal video display as the console.

    6. Boot the machine.

       When FreeBSD starts, the boot blocks echo the contents of /boot.config
       to the console. For example:

 /boot.config: -P
 Keyboard: no

       The second line appears only if -P is in /boot.config and indicates
       the presence or absence of the keyboard. These messages go to either
       the serial or internal console, or both, depending on the option in
       /boot.config:

       Options                         Message goes to                        
       none                            internal console                       
       -h                              serial console                         
       -D                              serial and internal consoles           
       -Dh                             serial and internal consoles           
       -P, keyboard present            internal console                       
       -P, keyboard absent             serial console                         

       After the message, there will be a small pause before the boot blocks
       continue loading the boot loader and before any further messages are
       printed to the console. Under normal circumstances, there is no need
       to interrupt the boot blocks, but one can do so in order to make sure
       things are set up correctly.

       Press any key, other than Enter, at the console to interrupt the boot
       process. The boot blocks will then prompt for further action:

 >> FreeBSD/i386 BOOT
 Default: 0:ad(0,a)/boot/loader
 boot:

       Verify that the above message appears on either the serial or internal
       console, or both, according to the options in /boot.config. If the
       message appears in the correct console, press Enter to continue the
       boot process.

       If there is no prompt on the serial terminal, something is wrong with
       the settings. Enter -h then Enter or Return to tell the boot block
       (and then the boot loader and the kernel) to choose the serial port
       for the console. Once the system is up, go back and check what went
       wrong.

   During the third stage of the boot process, one can still switch between
   the internal console and the serial console by setting appropriate
   environment variables in the boot loader. See loader(8) for more
   information.

  Note:

   This line in /boot/loader.conf or /boot/loader.conf.local configures the
   boot loader and the kernel to send their boot messages to the serial
   console, regardless of the options in /boot.config:

 console="comconsole"

   That line should be the first line of /boot/loader.conf so that boot
   messages are displayed on the serial console as early as possible.

   If that line does not exist, or if it is set to console="vidconsole", the
   boot loader and the kernel will use whichever console is indicated by -h
   in the boot block. See loader.conf(5) for more information.

   At the moment, the boot loader has no option equivalent to -P in the boot
   block, and there is no provision to automatically select the internal
   console and the serial console based on the presence of the keyboard.

  Tip:

   While it is not required, it is possible to provide a login prompt over
   the serial line. To configure this, edit the entry for the serial port in
   /etc/ttys using the instructions in Section 27.3.1, "Terminal
   Configuration". If the speed of the serial port has been changed, change
   std.9600 to match the new setting.

  27.6.3. Setting a Faster Serial Port Speed

   By default, the serial port settings are 9600 baud, 8 bits, no parity, and
   1 stop bit. To change the default console speed, use one of the following
   options:

     * Edit /etc/make.conf and set BOOT_COMCONSOLE_SPEED to the new console
       speed. Then, recompile and install the boot blocks and the boot
       loader:

 # cd /sys/boot
 # make clean
 # make
 # make install

       If the serial console is configured in some other way than by booting
       with -h, or if the serial console used by the kernel is different from
       the one used by the boot blocks, add the following option, with the
       desired speed, to a custom kernel configuration file and compile a new
       kernel:

 options CONSPEED=19200

     * Add the -S19200 boot option to /boot.config, replacing 19200 with the
       speed to use.

     * Add the following options to /boot/loader.conf. Replace 115200 with
       the speed to use.

 boot_multicons="YES"
 boot_serial="YES"
 comconsole_speed="115200"
 console="comconsole,vidconsole"

  27.6.4. Entering the DDB Debugger from the Serial Line

   To configure the ability to drop into the kernel debugger from the serial
   console, add the following options to a custom kernel configuration file
   and compile the kernel using the instructions in Chapter 8, Configuring
   the FreeBSD Kernel. Note that while this is useful for remote diagnostics,
   it is also dangerous if a spurious BREAK is generated on the serial port.
   Refer to ddb(4) and ddb(8) for more information about the kernel debugger.

 options BREAK_TO_DEBUGGER
 options DDB

Chapter 28. PPP

   Table of Contents

   28.1. Synopsis

   28.2. Configuring PPP

   28.3. Troubleshooting PPP Connections

   28.4. Using PPP over Ethernet (PPPoE)

   28.5. Using PPP over ATM (PPPoA)

28.1. Synopsis

   FreeBSD supports the Point-to-Point (PPP) protocol which can be used to
   establish a network or Internet connection using a dial-up modem. This
   chapter describes how to configure modem-based communication services in
   FreeBSD.

   After reading this chapter, you will know:

     * How to configure, use, and troubleshoot a PPP connection.

     * How to set up PPP over Ethernet (PPPoE).

     * How to set up PPP over ATM (PPPoA).

   Before reading this chapter, you should:

     * Be familiar with basic network terminology.

     * Understand the basics and purpose of a dial-up connection and PPP.

28.2. Configuring PPP

   FreeBSD provides built-in support for managing dial-up PPP connections
   using ppp(8). The default FreeBSD kernel provides support for tun which is
   used to interact with a modem hardware. Configuration is performed by
   editing at least one configuration file, and configuration files
   containing examples are provided. Finally, ppp is used to start and manage
   connections.

   In order to use a PPP connection, the following items are needed:

     * A dial-up account with an Internet Service Provider (ISP).

     * A dial-up modem.

     * The dial-up number for the ISP.

     * The login name and password assigned by the ISP.

     * The IP address of one or more DNS servers. Normally, the ISP provides
       these addresses. If it did not, FreeBSD can be configured to use DNS
       negotiation.

   If any of the required information is missing, contact the ISP.

   The following information may be supplied by the ISP, but is not
   necessary:

     * The IP address of the default gateway. If this information is unknown,
       the ISP will automatically provide the correct value during connection
       setup. When configuring PPP on FreeBSD, this address is referred to as
       HISADDR.

     * The subnet mask. If the ISP has not provided one, 255.255.255.255 will
       be used in the ppp(8) configuration file.

     * If the ISP has assigned a static IP address and hostname, it should be
       input into the configuration file. Otherwise, this information will be
       automatically provided during connection setup.

   The rest of this section demonstrates how to configure FreeBSD for common
   PPP connection scenarios. The required configuration file is
   /etc/ppp/ppp.conf and additional files and examples are available in
   /usr/share/examples/ppp/.

  Note:

   Throughout this section, many of the file examples display line numbers.
   These line numbers have been added to make it easier to follow the
   discussion and are not meant to be placed in the actual file.

   When editing a configuration file, proper indentation is important. Lines
   that end in a : start in the first column (beginning of the line) while
   all other lines should be indented as shown using spaces or tabs.

  28.2.1. Basic Configuration

   In order to configure a PPP connection, first edit /etc/ppp/ppp.conf with
   the dial-in information for the ISP. This file is described as follows:

 1     default:
 2       set log Phase Chat LCP IPCP CCP tun command
 3       ident user-ppp VERSION
 4       set device /dev/cuau0
 5       set speed 115200
 6       set dial "ABORT BUSY ABORT NO\\sCARRIER TIMEOUT 5 \
 7                 \"\" AT OK-AT-OK ATE1Q0 OK \\dATDT\\T TIMEOUT 40 CONNECT"
 8       set timeout 180
 9       enable dns
 10
 11    provider:
 12      set phone "(123) 456 7890"
 13      set authname foo
 14      set authkey bar
 15      set timeout 300
 16      set ifaddr x.x.x.x/0 y.y.y.y/0 255.255.255.255 0.0.0.0
 17      add default HISADDR

   Line 1:

           Identifies the default entry. Commands in this entry (lines 2
           through 9) are executed automatically when ppp is run.

   Line 2:

           Enables verbose logging parameters for testing the connection.
           Once the configuration is working satisfactorily, this line should
           be reduced to:

 set log phase tun

   Line 3:

           Displays the version of ppp(8) to the PPP software running on the
           other side of the connection.

   Line 4:

           Identifies the device to which the modem is connected, where COM1
           is /dev/cuau0 and COM2 is /dev/cuau1.

   Line 5:

           Sets the connection speed. If 115200 does not work on an older
           modem, try 38400 instead.

   Lines 6 & 7:

           The dial string written as an expect-send syntax. Refer to chat(8)
           for more information.

           Note that this command continues onto the next line for
           readability. Any command in ppp.conf may do this if the last
           character on the line is \.

   Line 8:

           Sets the idle timeout for the link in seconds.

   Line 9:

           Instructs the peer to confirm the DNS settings. If the local
           network is running its own DNS server, this line should be
           commented out, by adding a # at the beginning of the line, or
           removed.

   Line 10:

           A blank line for readability. Blank lines are ignored by ppp(8).

   Line 11:

           Identifies an entry called provider. This could be changed to the
           name of the ISP so that load ISP can be used to start the
           connection.

   Line 12:

           Use the phone number for the ISP. Multiple phone numbers may be
           specified using the colon (:) or pipe character (|) as a
           separator. To rotate through the numbers, use a colon. To always
           attempt to dial the first number first and only use the other
           numbers if the first number fails, use the pipe character. Always
           enclose the entire set of phone numbers between quotation marks
           (") to prevent dialing failures.

   Lines 13 & 14:

           Use the user name and password for the ISP.

   Line 15:

           Sets the default idle timeout in seconds for the connection. In
           this example, the connection will be closed automatically after
           300 seconds of inactivity. To prevent a timeout, set this value to
           zero.

   Line 16:

           Sets the interface addresses. The values used depend upon whether
           a static IP address has been obtained from the ISP or if it
           instead negotiates a dynamic IP address during connection.

           If the ISP has allocated a static IP address and default gateway,
           replace x.x.x.x with the static IP address and replace y.y.y.y
           with the IP address of the default gateway. If the ISP has only
           provided a static IP address without a gateway address, replace
           y.y.y.y with 10.0.0.2/0.

           If the IP address changes whenever a connection is made, change
           this line to the following value. This tells ppp(8) to use the IP
           Configuration Protocol (IPCP) to negotiate a dynamic IP address:

 set ifaddr 10.0.0.1/0 10.0.0.2/0 255.255.255.255 0.0.0.0

   Line 17:

           Keep this line as-is as it adds a default route to the gateway.
           The HISADDR will automatically be replaced with the gateway
           address specified on line 16. It is important that this line
           appears after line 16.

   Depending upon whether ppp(8) is started manually or automatically, a
   /etc/ppp/ppp.linkup may also need to be created which contains the
   following lines. This file is required when running ppp in -auto mode.
   This file is used after the connection has been established. At this
   point, the IP address will have been assigned and it is now be possible to
   add the routing table entries. When creating this file, make sure that
   provider matches the value demonstrated in line 11 of ppp.conf.

 provider:
       add default HISADDR

   This file is also needed when the default gateway address is "guessed" in
   a static IP address configuration. In this case, remove line 17 from
   ppp.conf and create /etc/ppp/ppp.linkup with the above two lines. More
   examples for this file can be found in /usr/share/examples/ppp/.

   By default, ppp must be run as root. To change this default, add the
   account of the user who should run ppp to the network group in /etc/group.

   Then, give the user access to one or more entries in /etc/ppp/ppp.conf
   with allow. For example, to give fred and mary permission to only the
   provider: entry, add this line to the provider: section:

 allow users fred mary

   To give the specified users access to all entries, put that line in the
   default section instead.

  28.2.2. Advanced Configuration

   It is possible to configure PPP to supply DNS and NetBIOS nameserver
   addresses on demand.

   To enable these extensions with PPP version 1.x, the following lines might
   be added to the relevant section of /etc/ppp/ppp.conf.

 enable msext
 set ns 203.14.100.1 203.14.100.2
 set nbns 203.14.100.5

   And for PPP version 2 and above:

 accept dns
 set dns 203.14.100.1 203.14.100.2
 set nbns 203.14.100.5

   This will tell the clients the primary and secondary name server
   addresses, and a NetBIOS nameserver host.

   In version 2 and above, if the set dns line is omitted, PPP will use the
   values found in /etc/resolv.conf.

    28.2.2.1. PAP and CHAP Authentication

   Some ISPs set their system up so that the authentication part of the
   connection is done using either of the PAP or CHAP authentication
   mechanisms. If this is the case, the ISP will not give a login: prompt at
   connection, but will start talking PPP immediately.

   PAP is less secure than CHAP, but security is not normally an issue here
   as passwords, although being sent as plain text with PAP, are being
   transmitted down a serial line only. There is not much room for crackers
   to "eavesdrop".

   The following alterations must be made:

 13      set authname MyUserName
 14      set authkey MyPassword
 15      set login

   Line 13:

           This line specifies the PAP/CHAP user name. Insert the correct
           value for MyUserName.

   Line 14:

           This line specifies the PAP/CHAP password. Insert the correct
           value for MyPassword. You may want to add an additional line, such
           as:

 16      accept PAP

           or

 16      accept CHAP

           to make it obvious that this is the intention, but PAP and CHAP
           are both accepted by default.

   Line 15:

           The ISP will not normally require a login to the server when using
           PAP or CHAP. Therefore, disable the "set login" string.

    28.2.2.2. Using PPP Network Address Translation Capability

   PPP has ability to use internal NAT without kernel diverting capabilities.
   This functionality may be enabled by the following line in
   /etc/ppp/ppp.conf:

 nat enable yes

   Alternatively, NAT may be enabled by command-line option -nat. There is
   also /etc/rc.conf knob named ppp_nat, which is enabled by default.

   When using this feature, it may be useful to include the following
   /etc/ppp/ppp.conf options to enable incoming connections forwarding:

 nat port tcp 10.0.0.2:ftp ftp
 nat port tcp 10.0.0.2:http http

   or do not trust the outside at all

 nat deny_incoming yes

  28.2.3. Final System Configuration

   While ppp is now configured, some edits still need to be made to
   /etc/rc.conf.

   Working from the top down in this file, make sure the hostname= line is
   set:

 hostname="foo.example.com"

   If the ISP has supplied a static IP address and name, use this name as the
   host name.

   Look for the network_interfaces variable. To configure the system to dial
   the ISP on demand, make sure the tun0 device is added to the list,
   otherwise remove it.

 network_interfaces="lo0 tun0"
 ifconfig_tun0=

  Note:

   The ifconfig_tun0 variable should be empty, and a file called
   /etc/start_if.tun0 should be created. This file should contain the line:

 ppp -auto mysystem

   This script is executed at network configuration time, starting the ppp
   daemon in automatic mode. If this machine acts as a gateway, consider
   including -alias. Refer to the manual page for further details.

   Make sure that the router program is set to NO with the following line in
   /etc/rc.conf:

 router_enable="NO"

   It is important that the routed daemon is not started, as routed tends to
   delete the default routing table entries created by ppp.

   It is probably a good idea to ensure that the sendmail_flags line does not
   include the -q option, otherwise sendmail will attempt to do a network
   lookup every now and then, possibly causing your machine to dial out. You
   may try:

 sendmail_flags="-bd"

   The downside is that sendmail is forced to re-examine the mail queue
   whenever the ppp link. To automate this, include !bg in ppp.linkup:

 1     provider:
 2       delete ALL
 3       add 0 0 HISADDR
 4       !bg sendmail -bd -q30m

   An alternative is to set up a "dfilter" to block SMTP traffic. Refer to
   the sample files for further details.

  28.2.4. Using ppp

   All that is left is to reboot the machine. After rebooting, either type:

 # ppp

   and then dial provider to start the PPP session, or, to configure ppp to
   establish sessions automatically when there is outbound traffic and
   start_if.tun0 does not exist, type:

 # ppp -auto provider

   It is possible to talk to the ppp program while it is running in the
   background, but only if a suitable diagnostic port has been set up. To do
   this, add the following line to the configuration:

 set server /var/run/ppp-tun%d DiagnosticPassword 0177

   This will tell PPP to listen to the specified UNIX(R) domain socket,
   asking clients for the specified password before allowing access. The %d
   in the name is replaced with the tun device number that is in use.

   Once a socket has been set up, the pppctl(8) program may be used in
   scripts that wish to manipulate the running program.

  28.2.5. Configuring Dial-in Services

   Section 27.4, "Dial-in Service" provides a good description on enabling
   dial-up services using getty(8).

   An alternative to getty is comms/mgetty+sendfax port), a smarter version
   of getty designed with dial-up lines in mind.

   The advantages of using mgetty is that it actively talks to modems,
   meaning if port is turned off in /etc/ttys then the modem will not answer
   the phone.

   Later versions of mgetty (from 0.99beta onwards) also support the
   automatic detection of PPP streams, allowing clients scriptless access to
   the server.

   Refer to http://mgetty.greenie.net/doc/mgetty_toc.html for more
   information on mgetty.

   By default the comms/mgetty+sendfax port comes with the AUTO_PPP option
   enabled allowing mgetty to detect the LCP phase of PPP connections and
   automatically spawn off a ppp shell. However, since the default
   login/password sequence does not occur it is necessary to authenticate
   users using either PAP or CHAP.

   This section assumes the user has successfully compiled, and installed the
   comms/mgetty+sendfax port on his system.

   Ensure that /usr/local/etc/mgetty+sendfax/login.config has the following:

 /AutoPPP/ -     - /etc/ppp/ppp-pap-dialup

   This tells mgetty to run ppp-pap-dialup for detected PPP connections.

   Create an executable file called /etc/ppp/ppp-pap-dialup containing the
   following:

 #!/bin/sh
 exec /usr/sbin/ppp -direct pap$IDENT

   For each dial-up line enabled in /etc/ttys, create a corresponding entry
   in /etc/ppp/ppp.conf. This will happily co-exist with the definitions we
   created above.

 pap:
   enable pap
   set ifaddr 203.14.100.1 203.14.100.20-203.14.100.40
   enable proxy

   Each user logging in with this method will need to have a
   username/password in /etc/ppp/ppp.secret, or alternatively add the
   following option to authenticate users via PAP from /etc/passwd.

 enable passwdauth

   To assign some users a static IP number, specify the number as the third
   argument in /etc/ppp/ppp.secret. See
   /usr/share/examples/ppp/ppp.secret.sample for examples.

28.3. Troubleshooting PPP Connections

   This section covers a few issues which may arise when using PPP over a
   modem connection. Some ISPs present the ssword prompt while others present
   password. If the ppp script is not written accordingly, the login attempt
   will fail. The most common way to debug ppp connections is by connecting
   manually as described in this section.

  28.3.1. Check the Device Nodes

   When using a custom kernel, make sure to include the following line in the
   kernel configuration file:

 device   uart

   The uart device is already included in the GENERIC kernel, so no
   additional steps are necessary in this case. Just check the dmesg output
   for the modem device with:

 # dmesg | grep uart

   This should display some pertinent output about the uart devices. These
   are the COM ports we need. If the modem acts like a standard serial port,
   it should be listed on uart1, or COM2. If so, a kernel rebuild is not
   required. When matching up, if the modem is on uart1, the modem device
   would be /dev/cuau1.

  28.3.2. Connecting Manually

   Connecting to the Internet by manually controlling ppp is quick, easy, and
   a great way to debug a connection or just get information on how the ISP
   treats ppp client connections. Lets start PPP from the command line. Note
   that in all of our examples we will use example as the hostname of the
   machine running PPP. To start ppp:

 # ppp

 ppp ON example> set device /dev/cuau1

   This second command sets the modem device to cuau1.

 ppp ON example> set speed 115200

   This sets the connection speed to 115,200 kbps.

 ppp ON example> enable dns

   This tells ppp to configure the resolver and add the nameserver lines to
   /etc/resolv.conf. If ppp cannot determine the hostname, it can manually be
   set later.

 ppp ON example> term

   This switches to "terminal" mode in order to manually control the modem.

 deflink: Entering terminal mode on /dev/cuau1
 type '~h' for help

 at
 OK
 atdt123456789

   Use at to initialize the modem, then use atdt and the number for the ISP
   to begin the dial in process.

 CONNECT

   Confirmation of the connection, if we are going to have any connection
   problems, unrelated to hardware, here is where we will attempt to resolve
   them.

 ISP Login:myusername

   At this prompt, return the prompt with the username that was provided by
   the ISP.

 ISP Pass:mypassword

   At this prompt, reply with the password that was provided by the ISP. Just
   like logging into FreeBSD, the password will not echo.

 Shell or PPP:ppp

   Depending on the ISP, this prompt might not appear. If it does, it is
   asking whether to use a shell on the provider or to start ppp. In this
   example, ppp was selected in order to establish an Internet connection.

 Ppp ON example>

   Notice that in this example the first p has been capitalized. This shows
   that we have successfully connected to the ISP.

 PPp ON example>

   We have successfully authenticated with our ISP and are waiting for the
   assigned IP address.

 PPP ON example>

   We have made an agreement on an IP address and successfully completed our
   connection.

 PPP ON example>add default HISADDR

   Here we add our default route, we need to do this before we can talk to
   the outside world as currently the only established connection is with the
   peer. If this fails due to existing routes, put a bang character ! in
   front of the add. Alternatively, set this before making the actual
   connection and it will negotiate a new route accordingly.

   If everything went good we should now have an active connection to the
   Internet, which could be thrown into the background using CTRL+z If PPP
   returns to ppp then the connection has bee lost. This is good to know
   because it shows the connection status. Capital P's represent a connection
   to the ISP and lowercase p's show that the connection has been lost.

  28.3.3. Debugging

   If a connection cannot be established, turn hardware flow CTS/RTS to off
   using set ctsrts off. This is mainly the case when connected to some
   PPP-capable terminal servers, where PPP hangs when it tries to write data
   to the communication link, and waits for a Clear To Send (CTS) signal
   which may never come. When using this option, include set accmap as it may
   be required to defeat hardware dependent on passing certain characters
   from end to end, most of the time XON/XOFF. Refer to ppp(8) for more
   information on this option and how it is used.

   An older modem may need set parity even. Parity is set at none be default,
   but is used for error checking with a large increase in traffic, on older
   modems.

   PPP may not return to the command mode, which is usually a negotiation
   error where the ISP is waiting for negotiating to begin. At this point,
   using ~p will force ppp to start sending the configuration information.

   If a login prompt never appears, PAP or CHAP authentication is most likely
   required. To use PAP or CHAP, add the following options to PPP before
   going into terminal mode:

 ppp ON example> set authname myusername

   Where myusername should be replaced with the username that was assigned by
   the ISP.

 ppp ON example> set authkey mypassword

   Where mypassword should be replaced with the password that was assigned by
   the ISP.

   If a connection is established, but cannot seem to find any domain name,
   try to ping(8) an IP address. If there is 100 percent (100%) packet loss,
   it is likely that a default route was not assigned. Double check that add
   default HISADDR was set during the connection. If a connection can be made
   to a remote IP address, it is possible that a resolver address has not
   been added to /etc/resolv.conf. This file should look like:

 domain example.com
 nameserver x.x.x.x
 nameserver y.y.y.y

   Where x.x.x.x and y.y.y.y should be replaced with the IP address of the
   ISP's DNS servers.

   To configure syslog(3) to provide logging for the PPP connection, make
   sure this line exists in /etc/syslog.conf:

 !ppp
 *.*     /var/log/ppp.log

28.4. Using PPP over Ethernet (PPPoE)

   This section describes how to set up PPP over Ethernet (PPPoE).

   Here is an example of a working ppp.conf:

 default:
   set log Phase tun command # you can add more detailed logging if you wish
   set ifaddr 10.0.0.1/0 10.0.0.2/0

 name_of_service_provider:
   set device PPPoE:xl1 # replace xl1 with your Ethernet device
   set authname YOURLOGINNAME
   set authkey YOURPASSWORD
   set dial
   set login
   add default HISADDR

   As root, run:

 # ppp -ddial name_of_service_provider

   Add the following to /etc/rc.conf:

 ppp_enable="YES"
 ppp_mode="ddial"
 ppp_nat="YES"   # if you want to enable nat for your local network, otherwise NO
 ppp_profile="name_of_service_provider"

  28.4.1. Using a PPPoE Service Tag

   Sometimes it will be necessary to use a service tag to establish the
   connection. Service tags are used to distinguish between different PPPoE
   servers attached to a given network.

   Any required service tag information should be in the documentation
   provided by the ISP.

   As a last resort, one could try installing the net/rr-pppoe package or
   port. Bear in mind however, this may de-program your modem and render it
   useless, so think twice before doing it. Simply install the program
   shipped with the modem. Then, access the System menu from the program. The
   name of the profile should be listed there. It is usually ISP.

   The profile name (service tag) will be used in the PPPoE configuration
   entry in ppp.conf as the provider part for set device. Refer to ppp(8) for
   full details. It should look like this:

 set device PPPoE:xl1:ISP

   Do not forget to change xl1 to the proper device for the Ethernet card.

   Do not forget to change ISP to the profile.

   For additional information, refer to Cheaper Broadband with FreeBSD on DSL
   by Renaud Waldura.

  28.4.2. PPPoE with a 3Com(R) HomeConnect(R) ADSL Modem Dual Link

   This modem does not follow the PPPoE specification defined in RFC 2516.

   In order to make FreeBSD capable of communicating with this device, a
   sysctl must be set. This can be done automatically at boot time by
   updating /etc/sysctl.conf:

 net.graph.nonstandard_pppoe=1

   or can be done immediately with the command:

 # sysctl net.graph.nonstandard_pppoe=1

   Unfortunately, because this is a system-wide setting, it is not possible
   to talk to a normal PPPoE client or server and a 3Com(R) HomeConnect(R)
   ADSL Modem at the same time.

28.5. Using PPP over ATM (PPPoA)

   The following describes how to set up PPP over ATM (PPPoA). PPPoA is a
   popular choice among European DSL providers.

  28.5.1. Using mpd

   The mpd application can be used to connect to a variety of services, in
   particular PPTP services. It can be installed using the net/mpd5 package
   or port. Many ADSL modems require that a PPTP tunnel is created between
   the modem and computer.

   Once installed, configure mpd to suit the provider's settings. The port
   places a set of sample configuration files which are well documented in
   /usr/local/etc/mpd/. A complete guide to configure mpd is available in
   HTML format in /usr/ports/share/doc/mpd/. Here is a sample configuration
   for connecting to an ADSL service with mpd. The configuration is spread
   over two files, first the mpd.conf:

  Note:

   This example mpd.conf only works with mpd 4.x.

 default:
     load adsl

 adsl:
     new -i ng0 adsl adsl
     set bundle authname username 1
     set bundle password password 2
     set bundle disable multilink

     set link no pap acfcomp protocomp
     set link disable chap
     set link accept chap
     set link keep-alive 30 10

     set ipcp no vjcomp
     set ipcp ranges 0.0.0.0/0 0.0.0.0/0

     set iface route default
     set iface disable on-demand
     set iface enable proxy-arp
     set iface idle 0

     open

   1   The username used to authenticate with your ISP.  
   2   The password used to authenticate with your ISP.  

   Information about the link, or links, to establish is found in mpd.links.
   An example mpd.links to accompany the above example is given beneath:

 adsl:
     set link type pptp
     set pptp mode active
     set pptp enable originate outcall
     set pptp self 10.0.0.1 1
     set pptp peer 10.0.0.138 2

   1 The IP address of FreeBSD computer running mpd.                          
   2 The IP address of the ADSL modem. The Alcatel SpeedTouch(TM) Home        
     defaults to 10.0.0.138.                                                  

   It is possible to initialize the connection easily by issuing the
   following command as root:

 # mpd -b adsl

   To view the status of the connection:

 % ifconfig ng0
 ng0: flags=88d1<UP,POINTOPOINT,RUNNING,NOARP,SIMPLEX,MULTICAST> mtu 1500
      inet 216.136.204.117 --> 204.152.186.171 netmask 0xffffffff

   Using mpd is the recommended way to connect to an ADSL service with
   FreeBSD.

  28.5.2. Using pptpclient

   It is also possible to use FreeBSD to connect to other PPPoA services
   using net/pptpclient.

   To use net/pptpclient to connect to a DSL service, install the port or
   package, then edit /etc/ppp/ppp.conf. An example section of ppp.conf is
   given below. For further information on ppp.conf options consult ppp(8).

 adsl:
  set log phase chat lcp ipcp ccp tun command
  set timeout 0
  enable dns
  set authname username 1
  set authkey password 2
  set ifaddr 0 0
  add default HISADDR

   1   The username for the DSL provider.  
   2   The password for your account.      

  Warning:

   Since the account's password is added to ppp.confin plain text form, make
   sure nobody can read the contents of this file:

 # chown root:wheel /etc/ppp/ppp.conf
 # chmod 600 /etc/ppp/ppp.conf

   This will open a tunnel for a PPP session to the DSL router. Ethernet DSL
   modems have a preconfigured LAN IP address to connect to. In the case of
   the Alcatel SpeedTouch(TM) Home, this address is 10.0.0.138. The router's
   documentation should list the address the device uses. To open the tunnel
   and start a PPP session:

 # pptp address adsl

  Tip:

   If an ampersand ("&") is added to the end of this command, pptp will
   return the prompt.

   A tun virtual tunnel device will be created for interaction between the
   pptp and ppp processes. Once the prompt is returned, or the pptp process
   has confirmed a connection, examine the tunnel:

 % ifconfig tun0
 tun0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1500
         inet 216.136.204.21 --> 204.152.186.171 netmask 0xffffff00
         Opened by PID 918

   If the connection fails, check the configuration of the router, which is
   usually accessible using a web browser. Also, examine the output of pptp
   and the contents of the log file, /var/log/ppp.log for clues.

Chapter 29. Electronic Mail

   Original work by Bill Lloyd.
   Rewritten by Jim Mock.
   Table of Contents

   29.1. Synopsis

   29.2. Mail Components

   29.3. Sendmail Configuration Files

   29.4. Changing the Mail Transfer Agent

   29.5. Troubleshooting

   29.6. Advanced Topics

   29.7. Setting Up to Send Only

   29.8. Using Mail with a Dialup Connection

   29.9. SMTP Authentication

   29.10. Mail User Agents

   29.11. Using fetchmail

   29.12. Using procmail

29.1. Synopsis

   "Electronic Mail", better known as email, is one of the most widely used
   forms of communication today. This chapter provides a basic introduction
   to running a mail server on FreeBSD, as well as an introduction to sending
   and receiving email using FreeBSD. For more complete coverage of this
   subject, refer to the books listed in Appendix B, Bibliography.

   After reading this chapter, you will know:

     * Which software components are involved in sending and receiving
       electronic mail.

     * Where basic Sendmail configuration files are located in FreeBSD.

     * The difference between remote and local mailboxes.

     * How to block spammers from illegally using a mail server as a relay.

     * How to install and configure an alternate Mail Transfer Agent,
       replacing Sendmail.

     * How to troubleshoot common mail server problems.

     * How to set up the system to send mail only.

     * How to use mail with a dialup connection.

     * How to configure SMTP authentication for added security.

     * How to install and use a Mail User Agent, such as mutt, to send and
       receive email.

     * How to download mail from a remote POP or IMAP server.

     * How to automatically apply filters and rules to incoming email.

   Before reading this chapter, you should:

     * Properly set up a network connection (Chapter 32, Advanced
       Networking).

     * Properly set up the DNS information for a mail host (Chapter 30,
       Network Servers).

     * Know how to install additional third-party software (Chapter 4,
       Installing Applications: Packages and Ports).

29.2. Mail Components

   There are five major parts involved in an email exchange: the Mail User
   Agent (MUA), the Mail Transfer Agent (MTA), a mail host, a remote or local
   mailbox, and DNS. This section provides an overview of these components.

   Mail User Agent (MUA)

           The Mail User Agent (MUA) is an application which is used to
           compose, send, and receive emails. This application can be a
           command line program, such as the built-in mail utility or a
           third-party application from the Ports Collection, such as mutt,
           alpine, or elm. Dozens of graphical programs are also available in
           the Ports Collection, including Claws Mail, Evolution, and
           Thunderbird. Some organizations provide a web mail program which
           can be accessed through a web browser. More information about
           installing and using a MUA on FreeBSD can be found in
           Section 29.10, "Mail User Agents".

   Mail Transfer Agent (MTA)

           The Mail Transfer Agent (MTA) is responsible for receiving
           incoming mail and delivering outgoing mail. FreeBSD ships with
           Sendmail as the default MTA, but it also supports numerous other
           mail server daemons, including Exim, Postfix, and qmail. Sendmail
           configuration is described in Section 29.3, "Sendmail
           Configuration Files". If another MTA is installed using the Ports
           Collection, refer to its post-installation message for
           FreeBSD-specific configuration details and the application's
           website for more general configuration instructions.

   Mail Host and Mailboxes

           The mail host is a server that is responsible for delivering and
           receiving mail for a host or a network. The mail host collects all
           mail sent to the domain and stores it either in the default mbox
           or the alternative Maildir format, depending on the configuration.
           Once mail has been stored, it may either be read locally using a
           MUA or remotely accessed and collected using protocols such as POP
           or IMAP. If mail is read locally, a POP or IMAP server does not
           need to be installed.

           To access mailboxes remotely, a POP or IMAP server is required as
           these protocols allow users to connect to their mailboxes from
           remote locations. IMAP offers several advantages over POP. These
           include the ability to store a copy of messages on a remote server
           after they are downloaded and concurrent updates. IMAP can be
           useful over low-speed links as it allows users to fetch the
           structure of messages without downloading them. It can also
           perform tasks such as searching on the server in order to minimize
           data transfer between clients and servers.

           Several POP and IMAP servers are available in the Ports
           Collection. These include mail/qpopper, mail/imap-uw,
           mail/courier-imap, and mail/dovecot2.

  Warning:

           It should be noted that both POP and IMAP transmit information,
           including username and password credentials, in clear-text. To
           secure the transmission of information across these protocols,
           consider tunneling sessions over ssh(1) (Section 14.8.1.2, "SSH
           Tunneling") or using SSL (Section 14.6, "OpenSSL").

   Domain Name System (DNS)

           The Domain Name System (DNS) and its daemon named play a large
           role in the delivery of email. In order to deliver mail from one
           site to another, the MTA will look up the remote site in DNS to
           determine which host will receive mail for the destination. This
           process also occurs when mail is sent from a remote host to the
           MTA.

           In addition to mapping hostnames to IP addresses, DNS is
           responsible for storing information specific to mail delivery,
           known as Mail eXchanger MX records. The MX record specifies which
           hosts will receive mail for a particular domain.

           To view the MX records for a domain, specify the type of record.
           Refer to host(1), for more details about this command:

 % host -t mx FreeBSD.org
 FreeBSD.org mail is handled by 10 mx1.FreeBSD.org

           Refer to Section 30.7, "Domain Name System (DNS)" for more
           information about DNS and its configuration.

29.3. Sendmail Configuration Files

   Contributed by Christopher Shumway.

   Sendmail is the default MTA installed with FreeBSD. It accepts mail from
   MUAs and delivers it to the appropriate mail host, as defined by its
   configuration. Sendmail can also accept network connections and deliver
   mail to local mailboxes or to another program.

   The configuration files for Sendmail are located in /etc/mail. This
   section describes these files in more detail.

   /etc/mail/access

           This access database file defines which hosts or IP addresses have
           access to the local mail server and what kind of access they have.
           Hosts listed as OK, which is the default option, are allowed to
           send mail to this host as long as the mail's final destination is
           the local machine. Hosts listed as REJECT are rejected for all
           mail connections. Hosts listed as RELAY are allowed to send mail
           for any destination using this mail server. Hosts listed as ERROR
           will have their mail returned with the specified mail error. If a
           host is listed as SKIP, Sendmail will abort the current search for
           this entry without accepting or rejecting the mail. Hosts listed
           as QUARANTINE will have their messages held and will receive the
           specified text as the reason for the hold.

           Examples of using these options for both IPv4 and IPv6 addresses
           can be found in the FreeBSD sample configuration,
           /etc/mail/access.sample:

 # $FreeBSD$
 #
 # Mail relay access control list.  Default is to reject mail unless the
 # destination is local, or listed in /etc/mail/local-host-names
 #
 ## Examples (commented out for safety)
 #From:cyberspammer.com          ERROR:"550 We don't accept mail from spammers"
 #From:okay.cyberspammer.com     OK
 #Connect:sendmail.org           RELAY
 #To:sendmail.org                RELAY
 #Connect:128.32                 RELAY
 #Connect:128.32.2               SKIP
 #Connect:IPv6:1:2:3:4:5:6:7     RELAY
 #Connect:suspicious.example.com QUARANTINE:Mail from suspicious host
 #Connect:[127.0.0.3]            OK
 #Connect:[IPv6:1:2:3:4:5:6:7:8] OK

           To configure the access database, use the format shown in the
           sample to make entries in /etc/mail/access, but do not put a
           comment symbol (#) in front of the entries. Create an entry for
           each host or network whose access should be configured. Mail
           senders that match the left side of the table are affected by the
           action on the right side of the table.

           Whenever this file is updated, update its database and restart
           Sendmail:

 # makemap hash /etc/mail/access < /etc/mail/access
 # service sendmail restart

   /etc/mail/aliases

           This database file contains a list of virtual mailboxes that are
           expanded to users, files, programs, or other aliases. Here are a
           few entries to illustrate the file format:

 root: localuser
 ftp-bugs: joe,eric,paul
 bit.bucket:  /dev/null
 procmail: "|/usr/local/bin/procmail"

           The mailbox name on the left side of the colon is expanded to the
           target(s) on the right. The first entry expands the root mailbox
           to the localuser mailbox, which is then looked up in the
           /etc/mail/aliases database. If no match is found, the message is
           delivered to localuser. The second entry shows a mail list. Mail
           to ftp-bugs is expanded to the three local mailboxes joe, eric,
           and paul. A remote mailbox could be specified as user@example.com.
           The third entry shows how to write mail to a file, in this case
           /dev/null. The last entry demonstrates how to send mail to a
           program, /usr/local/bin/procmail, through a UNIX(R) pipe. Refer to
           aliases(5) for more information about the format of this file.

           Whenever this file is updated, run newaliases to update and
           initialize the aliases database.

   /etc/mail/sendmail.cf

           This is the master configuration file for Sendmail. It controls
           the overall behavior of Sendmail, including everything from
           rewriting email addresses to printing rejection messages to remote
           mail servers. Accordingly, this configuration file is quite
           complex. Fortunately, this file rarely needs to be changed for
           standard mail servers.

           The master Sendmail configuration file can be built from m4(1)
           macros that define the features and behavior of Sendmail. Refer to
           /usr/src/contrib/sendmail/cf/README for some of the details.

           Whenever changes to this file are made, Sendmail needs to be
           restarted for the changes to take effect.

   /etc/mail/virtusertable

           This database file maps mail addresses for virtual domains and
           users to real mailboxes. These mailboxes can be local, remote,
           aliases defined in /etc/mail/aliases, or files. This allows
           multiple virtual domains to be hosted on one machine.

           FreeBSD provides a sample configuration file in
           /etc/mail/virtusertable.sample to further demonstrate its format.
           The following example demonstrates how to create custom entries
           using that format:

 root@example.com                root
 postmaster@example.com          postmaster@noc.example.net
 @example.com                    joe

           This file is processed in a first match order. When an email
           address matches the address on the left, it is mapped to the local
           mailbox listed on the right. The format of the first entry in this
           example maps a specific email address to a local mailbox, whereas
           the format of the second entry maps a specific email address to a
           remote mailbox. Finally, any email address from example.com which
           has not matched any of the previous entries will match the last
           mapping and be sent to the local mailbox joe. When creating custom
           entries, use this format and add them to /etc/mail/virtusertable.
           Whenever this file is edited, update its database and restart
           Sendmail:

 # makemap hash /etc/mail/virtusertable < /etc/mail/virtusertable
 # service sendmail restart

   /etc/mail/relay-domains

           In a default FreeBSD installation, Sendmail is configured to only
           send mail from the host it is running on. For example, if a POP
           server is available, users will be able to check mail from remote
           locations but they will not be able to send outgoing emails from
           outside locations. Typically, a few moments after the attempt, an
           email will be sent from MAILER-DAEMON with a 5.7 Relaying Denied
           message.

           The most straightforward solution is to add the ISP's FQDN to
           /etc/mail/relay-domains. If multiple addresses are needed, add
           them one per line:

 your.isp.example.com
 other.isp.example.net
 users-isp.example.org
 www.example.org

           After creating or editing this file, restart Sendmail with service
           sendmail restart.

           Now any mail sent through the system by any host in this list,
           provided the user has an account on the system, will succeed. This
           allows users to send mail from the system remotely without opening
           the system up to relaying SPAM from the Internet.

29.4. Changing the Mail Transfer Agent

   Written by Andrew Boothman.
   Information taken from emails written by Gregory Neil Shapiro.

   FreeBSD comes with Sendmail already installed as the MTA which is in
   charge of outgoing and incoming mail. However, the system administrator
   can change the system's MTA. A wide choice of alternative MTAs is
   available from the mail category of the FreeBSD Ports Collection.

   Once a new MTA is installed, configure and test the new software before
   replacing Sendmail. Refer to the documentation of the new MTA for
   information on how to configure the software.

   Once the new MTA is working, use the instructions in this section to
   disable Sendmail and configure FreeBSD to use the replacement MTA.

  29.4.1. Disable Sendmail

  Warning:

   If Sendmail's outgoing mail service is disabled, it is important that it
   is replaced with an alternative mail delivery system. Otherwise, system
   functions such as periodic(8) will be unable to deliver their results by
   email. Many parts of the system expect a functional MTA. If applications
   continue to use Sendmail's binaries to try to send email after they are
   disabled, mail could go into an inactive Sendmail queue and never be
   delivered.

   In order to completely disable Sendmail, add or edit the following lines
   in /etc/rc.conf:

 sendmail_enable="NO"
 sendmail_submit_enable="NO"
 sendmail_outbound_enable="NO"
 sendmail_msp_queue_enable="NO"

   To only disable Sendmail's incoming mail service, use only this entry in
   /etc/rc.conf:

 sendmail_enable="NO"

   More information on Sendmail's startup options is available in
   rc.sendmail(8).

  29.4.2. Replace the Default MTA

   When a new MTA is installed using the Ports Collection, its startup script
   is also installed and startup instructions are mentioned in its package
   message. Before starting the new MTA, stop the running Sendmail processes.
   This example stops all of these services, then starts the Postfix service:

 # service sendmail stop
 # service postfix start

   To start the replacement MTA at system boot, add its configuration line to
   /etc/rc.conf. This entry enables the Postfix MTA:

 postfix_enable="YES"

   Some extra configuration is needed as Sendmail is so ubiquitous that some
   software assumes it is already installed and configured. Check
   /etc/periodic.conf and make sure that these values are set to NO. If this
   file does not exist, create it with these entries:

 daily_clean_hoststat_enable="NO"
 daily_status_mail_rejects_enable="NO"
 daily_status_include_submit_mailq="NO"
 daily_submit_queuerun="NO"

   Some alternative MTAs provide their own compatible implementations of the
   Sendmail command-line interface in order to facilitate using them as
   drop-in replacements for Sendmail. However, some MUAs may try to execute
   standard Sendmail binaries instead of the new MTA's binaries. FreeBSD uses
   /etc/mail/mailer.conf to map the expected Sendmail binaries to the
   location of the new binaries. More information about this mapping can be
   found in mailwrapper(8).

   The default /etc/mail/mailer.conf looks like this:

 # $FreeBSD$
 #
 # Execute the "real" sendmail program, named /usr/libexec/sendmail/sendmail
 #
 sendmail        /usr/libexec/sendmail/sendmail
 send-mail       /usr/libexec/sendmail/sendmail
 mailq           /usr/libexec/sendmail/sendmail
 newaliases      /usr/libexec/sendmail/sendmail
 hoststat        /usr/libexec/sendmail/sendmail
 purgestat       /usr/libexec/sendmail/sendmail

   When any of the commands listed on the left are run, the system actually
   executes the associated command shown on the right. This system makes it
   easy to change what binaries are executed when these default binaries are
   invoked.

   Some MTAs, when installed using the Ports Collection, will prompt to
   update this file for the new binaries. For example, Postfix will update
   the file like this:

 #
 # Execute the Postfix sendmail program, named /usr/local/sbin/sendmail
 #
 sendmail        /usr/local/sbin/sendmail
 send-mail       /usr/local/sbin/sendmail
 mailq           /usr/local/sbin/sendmail
 newaliases      /usr/local/sbin/sendmail

   If the installation of the MTA does not automatically update
   /etc/mail/mailer.conf, edit this file in a text editor so that it points
   to the new binaries. This example points to the binaries installed by
   mail/ssmtp:

 sendmail        /usr/local/sbin/ssmtp
 send-mail       /usr/local/sbin/ssmtp
 mailq           /usr/local/sbin/ssmtp
 newaliases      /usr/local/sbin/ssmtp
 hoststat        /usr/bin/true
 purgestat       /usr/bin/true

   Once everything is configured, it is recommended to reboot the system.
   Rebooting provides the opportunity to ensure that the system is correctly
   configured to start the new MTA automatically on boot.

29.5. Troubleshooting

   29.5.1. Why do I have to use the FQDN for hosts on my site?

   29.5.2. How can I run a mail server on a dial-up PPP host?

29.5.1. Why do I have to use the FQDN for hosts on my site?                        
        The host may actually be in a different domain. For example, in order for  
        a host in foo.bar.edu to reach a host called mumble in the bar.edu domain, 
        refer to it by the Fully-Qualified Domain Name FQDN, mumble.bar.edu,       
        instead of just mumble.                                                    
                                                                                   
        This is because the version of BIND which ships with FreeBSD no longer     
        provides default abbreviations for non-FQDNs other than the local domain.  
        An unqualified host such as mumble must either be found as                 
        mumble.foo.bar.edu, or it will be searched for in the root domain.         
                                                                                   
        In older versions of BIND, the search continued across mumble.bar.edu, and 
        mumble.edu. RFC 1535 details why this is considered bad practice or even a 
        security hole.                                                             
                                                                                   
        As a good workaround, place the line:                                      
                                                                                   
        search foo.bar.edu bar.edu                                                 
                                                                                   
        instead of the previous:                                                   
                                                                                   
        domain foo.bar.edu                                                         
                                                                                   
        into /etc/resolv.conf. However, make sure that the search order does not   
        go beyond the "boundary between local and public administration", as RFC   
        1535 calls it.                                                             
29.5.2. How can I run a mail server on a dial-up PPP host?                         
        Connect to a FreeBSD mail gateway on the LAN. The PPP connection is        
        non-dedicated.                                                             
                                                                                   
        One way to do this is to get a full-time Internet server to provide        
        secondary MX services for the domain. In this example, the domain is       
        example.com and the ISP has configured example.net to provide secondary MX 
        services to the domain:                                                    
                                                                                   
        example.com.          MX        10      example.com.                       
                              MX        20      example.net.                       
                                                                                   
        Only one host should be specified as the final recipient. For Sendmail,    
        add Cw example.com in /etc/mail/sendmail.cf on example.com.                
                                                                                   
        When the sending MTA attempts to deliver mail, it will try to connect to   
        the system, example.com, over the PPP link. This will time out if the      
        destination is offline. The MTA will automatically deliver it to the       
        secondary MX site at the Internet Service Provider (ISP), example.net. The 
        secondary MX site will periodically try to connect to the primary MX host, 
        example.com.                                                               
                                                                                   
        Use something like this as a login script:                                 
                                                                                   
        #!/bin/sh                                                                  
        # Put me in /usr/local/bin/pppmyisp                                        
        ( sleep 60 ; /usr/sbin/sendmail -q ) &                                     
        /usr/sbin/ppp -direct pppmyisp                                             
                                                                                   
        When creating a separate login script for users, instead use sendmail      
        -qRexample.com in the script above. This will force all mail in the queue  
        for example.com to be processed immediately.                               
                                                                                   
        A further refinement of the situation can be seen from this example from   
        the FreeBSD Internet service provider's mailing list:                      
                                                                                   
        > we provide the secondary MX for a customer. The customer connects to     
        > our services several times a day automatically to get the mails to       
        > his primary MX (We do not call his site when a mail for his domains      
        > arrived). Our sendmail sends the mailqueue every 30 minutes. At the      
        > moment he has to stay 30 minutes online to be sure that all mail is      
        > gone to the primary MX.                                                  
        >                                                                          
        > Is there a command that would initiate sendmail to send all the mails    
        > now? The user has not root-privileges on our machine of course.          
                                                                                   
        In the "privacy flags" section of sendmail.cf, there is a                  
        definition Opgoaway,restrictqrun                                           
                                                                                   
        Remove restrictqrun to allow non-root users to start the queue processing. 
        You might also like to rearrange the MXs. We are the 1st MX for our        
        customers like this, and we have defined:                                  
                                                                                   
        # If we are the best MX for a host, try directly instead of generating     
        # local config error.                                                      
        OwTrue                                                                     
                                                                                   
        That way a remote site will deliver straight to you, without trying        
        the customer connection.  You then send to your customer.  Only works for  
        "hosts", so you need to get your customer to name their mail               
        machine "customer.com" as well as                                          
        "hostname.customer.com" in the DNS.  Just put an A record in               
        the DNS for "customer.com".                                                

29.6. Advanced Topics

   This section covers more involved topics such as mail configuration and
   setting up mail for an entire domain.

  29.6.1. Basic Configuration

   Out of the box, one can send email to external hosts as long as
   /etc/resolv.conf is configured or the network has access to a configured
   DNS server. To have email delivered to the MTA on the FreeBSD host, do one
   of the following:

     * Run a DNS server for the domain.

     * Get mail delivered directly to the FQDN for the machine.

   In order to have mail delivered directly to a host, it must have a
   permanent static IP address, not a dynamic IP address. If the system is
   behind a firewall, it must be configured to allow SMTP traffic. To receive
   mail directly at a host, one of these two must be configured:

     * Make sure that the lowest-numbered MX record in DNS points to the
       host's static IP address.

     * Make sure there is no MX entry in the DNS for the host.

   Either of the above will allow mail to be received directly at the host.

   Try this:

 # hostname
 example.FreeBSD.org
 # host example.FreeBSD.org
 example.FreeBSD.org has address 204.216.27.XX

   In this example, mail sent directly to <yourlogin@example.FreeBSD.org>
   should work without problems, assuming Sendmail is running correctly on
   example.FreeBSD.org.

   For this example:

 # host example.FreeBSD.org
 example.FreeBSD.org has address 204.216.27.XX
 example.FreeBSD.org mail is handled (pri=10) by nevdull.FreeBSD.org

   All mail sent to example.FreeBSD.org will be collected on hub under the
   same username instead of being sent directly to your host.

   The above information is handled by the DNS server. The DNS record that
   carries mail routing information is the MX entry. If no MX record exists,
   mail will be delivered directly to the host by way of its IP address.

   The MX entry for freefall.FreeBSD.org at one time looked like this:

 freefall                MX      30      mail.crl.net
 freefall                MX      40      agora.rdrop.com
 freefall                MX      10      freefall.FreeBSD.org
 freefall                MX      20      who.cdrom.com

   freefall had many MX entries. The lowest MX number is the host that
   receives mail directly, if available. If it is not accessible for some
   reason, the next lower-numbered host will accept messages temporarily, and
   pass it along when a lower-numbered host becomes available.

   Alternate MX sites should have separate Internet connections in order to
   be most useful. Your ISP can provide this service.

  29.6.2. Mail for a Domain

   When configuring a MTA for a network, any mail sent to hosts in its domain
   should be diverted to the MTA so that users can receive their mail on the
   master mail server.

   To make life easiest, a user account with the same username should exist
   on both the MTA and the system with the MUA. Use adduser(8) to create the
   user accounts.

   The MTA must be the designated mail exchanger for each workstation on the
   network. This is done in theDNS configuration with an MX record:

 example.FreeBSD.org     A       204.216.27.XX           ; Workstation
                         MX      10 nevdull.FreeBSD.org  ; Mailhost

   This will redirect mail for the workstation to the MTA no matter where the
   A record points. The mail is sent to the MX host.

   This must be configured on a DNS server. If the network does not run its
   own DNS server, talk to the ISP or DNS provider.

   The following is an example of virtual email hosting. Consider a customer
   with the domain customer1.org, where all the mail for customer1.org should
   be sent to mail.myhost.com. The DNS entry should look like this:

 customer1.org           MX      10      mail.myhost.com

   An A record is not needed for customer1.org in order to only handle email
   for that domain. However, running ping against customer1.org will not work
   unless an A record exists for it.

   Tell the MTA which domains and/or hostnames it should accept mail for.
   Either of the following will work for Sendmail:

     * Add the hosts to /etc/mail/local-host-names when using the
       FEATURE(use_cw_file).

     * Add a Cwyour.host.com line to /etc/sendmail.cf.

29.7. Setting Up to Send Only

   Contributed by Bill Moran.

   There are many instances where one may only want to send mail through a
   relay. Some examples are:

     * The computer is a desktop machine that needs to use programs such as
       mail(1), using the ISP's mail relay.

     * The computer is a server that does not handle mail locally, but needs
       to pass off all mail to a relay for processing.

   While any MTA is capable of filling this particular niche, it can be
   difficult to properly configure a full-featured MTA just to handle
   offloading mail. Programs such as Sendmail and Postfix are overkill for
   this use.

   Additionally, a typical Internet access service agreement may forbid one
   from running a "mail server".

   The easiest way to fulfill those needs is to install the mail/ssmtp port:

 # cd /usr/ports/mail/ssmtp
 # make install replace clean

   Once installed, mail/ssmtp can be configured with
   /usr/local/etc/ssmtp/ssmtp.conf:

 root=yourrealemail@example.com
 mailhub=mail.example.com
 rewriteDomain=example.com
 hostname=_HOSTNAME_

   Use the real email address for root. Enter the ISP's outgoing mail relay
   in place of mail.example.com. Some ISPs call this the "outgoing mail
   server" or "SMTP server".

   Make sure to disable Sendmail, including the outgoing mail service. See
   Section 29.4.1, "Disable Sendmail" for details.

   mail/ssmtp has some other options available. Refer to the examples in
   /usr/local/etc/ssmtp or the manual page of ssmtp for more information.

   Setting up ssmtp in this manner allows any software on the computer that
   needs to send mail to function properly, while not violating the ISP's
   usage policy or allowing the computer to be hijacked for spamming.

29.8. Using Mail with a Dialup Connection

   When using a static IP address, one should not need to adjust the default
   configuration. Set the hostname to the assigned Internet name and Sendmail
   will do the rest.

   When using a dynamically assigned IP address and a dialup PPP connection
   to the Internet, one usually has a mailbox on the ISP's mail server. In
   this example, the ISP's domain is example.net, the user name is user, the
   hostname is bsd.home, and the ISP has allowed relay.example.net as a mail
   relay.

   In order to retrieve mail from the ISP's mailbox, install a retrieval
   agent from the Ports Collection. mail/fetchmail is a good choice as it
   supports many different protocols. Usually, the ISP will provide POP. When
   using user PPP, email can be automatically fetched when an Internet
   connection is established with the following entry in /etc/ppp/ppp.linkup:

 MYADDR:
 !bg su user -c fetchmail

   When using Sendmail to deliver mail to non-local accounts, configure
   Sendmail to process the mail queue as soon as the Internet connection is
   established. To do this, add this line after the above fetchmail entry in
   /etc/ppp/ppp.linkup:

   !bg su user -c "sendmail -q"

   In this example, there is an account for user on bsd.home. In the home
   directory of user on bsd.home, create a .fetchmailrc which contains this
   line:

 poll example.net protocol pop3 fetchall pass MySecret

   This file should not be readable by anyone except user as it contains the
   password MySecret.

   In order to send mail with the correct from: header, configure Sendmail to
   use <user@example.net> rather than <user@bsd.home> and to send all mail
   via relay.example.net, allowing quicker mail transmission.

   The following .mc should suffice:

 VERSIONID(`bsd.home.mc version 1.0')
 OSTYPE(bsd4.4)dnl
 FEATURE(nouucp)dnl
 MAILER(local)dnl
 MAILER(smtp)dnl
 Cwlocalhost
 Cwbsd.home
 MASQUERADE_AS(`example.net')dnl
 FEATURE(allmasquerade)dnl
 FEATURE(masquerade_envelope)dnl
 FEATURE(nocanonify)dnl
 FEATURE(nodns)dnl
 define(`SMART_HOST', `relay.example.net')
 Dmbsd.home
 define(`confDOMAIN_NAME',`bsd.home')dnl
 define(`confDELIVERY_MODE',`deferred')dnl

   Refer to the previous section for details of how to convert this file into
   the sendmail.cf format. Do not forget to restart Sendmail after updating
   sendmail.cf.

29.9. SMTP Authentication

   Written by James Gorham.

   Configuring SMTP authentication on the MTA provides a number of benefits.
   SMTP authentication adds a layer of security to Sendmail, and provides
   mobile users who switch hosts the ability to use the same MTA without the
   need to reconfigure their mail client's settings each time.

    1. Install security/cyrus-sasl2 from the Ports Collection. This port
       supports a number of compile-time options. For the SMTP authentication
       method demonstrated in this example, make sure that LOGIN is not
       disabled.

    2. After installing security/cyrus-sasl2, edit
       /usr/local/lib/sasl2/Sendmail.conf, or create it if it does not exist,
       and add the following line:

 pwcheck_method: saslauthd

    3. Next, install security/cyrus-sasl2-saslauthd and add the following
       line to /etc/rc.conf:

 saslauthd_enable="YES"

       Finally, start the saslauthd daemon:

 # service saslauthd start

       This daemon serves as a broker for Sendmail to authenticate against
       the FreeBSD passwd(5) database. This saves the trouble of creating a
       new set of usernames and passwords for each user that needs to use
       SMTP authentication, and keeps the login and mail password the same.

    4. Next, edit /etc/make.conf and add the following lines:

 SENDMAIL_CFLAGS=-I/usr/local/include/sasl -DSASL
 SENDMAIL_LDADD=/usr/local/lib/libsasl2.so

       These lines provide Sendmail the proper configuration options for
       linking to cyrus-sasl2 at compile time. Make sure that cyrus-sasl2 has
       been installed before recompiling Sendmail.

    5. Recompile Sendmail by executing the following commands:

 # cd /usr/src/lib/libsmutil
 # make cleandir && make obj && make
 # cd /usr/src/lib/libsm
 # make cleandir && make obj && make
 # cd /usr/src/usr.sbin/sendmail
 # make cleandir && make obj && make && make install

       This compile should not have any problems if /usr/src has not changed
       extensively and the shared libraries it needs are available.

    6. After Sendmail has been compiled and reinstalled, edit
       /etc/mail/freebsd.mc or the local .mc. Many administrators choose to
       use the output from hostname(1) as the name of .mc for uniqueness. Add
       these lines:

 dnl set SASL options
 TRUST_AUTH_MECH(`GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN')dnl
 define(`confAUTH_MECHANISMS', `GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN')dnl

       These options configure the different methods available to Sendmail
       for authenticating users. To use a method other than pwcheck, refer to
       the Sendmail documentation.

    7. Finally, run make(1) while in /etc/mail. That will run the new .mc and
       create a .cf named either freebsd.cf or the name used for the local
       .mc. Then, run make install restart, which will copy the file to
       sendmail.cf, and properly restart Sendmail. For more information about
       this process, refer to /etc/mail/Makefile.

   To test the configuration, use a MUA to send a test message. For further
   investigation, set the LogLevel of Sendmail to 13 and watch
   /var/log/maillog for any errors.

   For more information, refer to SMTP authentication.

29.10. Mail User Agents

   Contributed by Marc Silver.

   A MUA is an application that is used to send and receive email. As email
   "evolves" and becomes more complex, MUAs are becoming increasingly
   powerful and provide users increased functionality and flexibility. The
   mail category of the FreeBSD Ports Collection contains numerous MUAs.
   These include graphical email clients such as Evolution or Balsa and
   console based clients such as mutt or alpine.

  29.10.1. mail

   mail(1) is the default MUA installed with FreeBSD. It is a console based
   MUA that offers the basic functionality required to send and receive
   text-based email. It provides limited attachment support and can only
   access local mailboxes.

   Although mail does not natively support interaction with POP or IMAP
   servers, these mailboxes may be downloaded to a local mbox using an
   application such as fetchmail.

   In order to send and receive email, run mail:

 % mail

   The contents of the user's mailbox in /var/mail are automatically read by
   mail. Should the mailbox be empty, the utility exits with a message
   indicating that no mail could be found. If mail exists, the application
   interface starts, and a list of messages will be displayed. Messages are
   automatically numbered, as can be seen in the following example:

 Mail version 8.1 6/6/93.  Type ? for help.
 "/var/mail/marcs": 3 messages 3 new
 >N  1 root@localhost        Mon Mar  8 14:05  14/510   "test"
  N  2 root@localhost        Mon Mar  8 14:05  14/509   "user account"
  N  3 root@localhost        Mon Mar  8 14:05  14/509   "sample"

   Messages can now be read by typing t followed by the message number. This
   example reads the first email:

 & t 1
 Message 1:
 From root@localhost  Mon Mar  8 14:05:52 2004
 X-Original-To: marcs@localhost
 Delivered-To: marcs@localhost
 To: marcs@localhost
 Subject: test
 Date: Mon,  8 Mar 2004 14:05:52 +0200 (SAST)
 From: root@localhost (Charlie Root)

 This is a test message, please reply if you receive it.

   As seen in this example, the message will be displayed with full headers.
   To display the list of messages again, press h.

   If the email requires a reply, press either R or r mail keys. R instructs
   mail to reply only to the sender of the email, while r replies to all
   other recipients of the message. These commands can be suffixed with the
   mail number of the message to reply to. After typing the response, the end
   of the message should be marked by a single . on its own line. An example
   can be seen below:

 & R 1
 To: root@localhost
 Subject: Re: test

 Thank you, I did get your email.
 .
 EOT

   In order to send a new email, press m, followed by the recipient email
   address. Multiple recipients may be specified by separating each address
   with the , delimiter. The subject of the message may then be entered,
   followed by the message contents. The end of the message should be
   specified by putting a single . on its own line.

 & mail root@localhost
 Subject: I mastered mail

 Now I can send and receive email using mail ... :)
 .
 EOT

   While using mail, press ? to display help at any time. Refer to mail(1)
   for more help on how to use mail.

  Note:

   mail(1) was not designed to handle attachments and thus deals with them
   poorly. Newer MUAs handle attachments in a more intelligent way. Users who
   prefer to use mail may find the converters/mpack port to be of
   considerable use.

  29.10.2. mutt

   mutt is a powerful MUA, with many features, including:

     * The ability to thread messages.

     * PGP support for digital signing and encryption of email.

     * MIME support.

     * Maildir support.

     * Highly customizable.

   Refer to http://www.mutt.org for more information on mutt.

   mutt may be installed using the mail/mutt port. After the port has been
   installed, mutt can be started by issuing the following command:

 % mutt

   mutt will automatically read and display the contents of the user mailbox
   in /var/mail. If no mails are found, mutt will wait for commands from the
   user. The example below shows mutt displaying a list of messages:

   To read an email, select it using the cursor keys and press Enter. An
   example of mutt displaying email can be seen below:

   Similar to mail(1), mutt can be used to reply only to the sender of the
   message as well as to all recipients. To reply only to the sender of the
   email, press r. To send a group reply to the original sender as well as
   all the message recipients, press g.

  Note:

   By default, mutt uses the vi(1) editor for creating and replying to
   emails. Each user can customize this by creating or editing the .muttrc in
   their home directory and setting the editor variable or by setting the
   EDITOR environment variable. Refer to http://www.mutt.org/ for more
   information about configuring mutt.

   To compose a new mail message, press m. After a valid subject has been
   given, mutt will start vi(1) so the email can be written. Once the
   contents of the email are complete, save and quit from vi. mutt will
   resume, displaying a summary screen of the mail that is to be delivered.
   In order to send the mail, press y. An example of the summary screen can
   be seen below:

   mutt contains extensive help which can be accessed from most of the menus
   by pressing ?. The top line also displays the keyboard shortcuts where
   appropriate.

  29.10.3. alpine

   alpine is aimed at a beginner user, but also includes some advanced
   features.

  Warning:

   alpine has had several remote vulnerabilities discovered in the past,
   which allowed remote attackers to execute arbitrary code as users on the
   local system, by the action of sending a specially-prepared email. While
   known problems have been fixed, alpine code is written in an insecure
   style and the FreeBSD Security Officer believes there are likely to be
   other undiscovered vulnerabilities. Users install alpine at their own
   risk.

   The current version of alpine may be installed using the mail/alpine port.
   Once the port has installed, alpine can be started by issuing the
   following command:

 % alpine

   The first time alpine runs, it displays a greeting page with a brief
   introduction, as well as a request from the alpine development team to
   send an anonymous email message allowing them to judge how many users are
   using their client. To send this anonymous message, press Enter.
   Alternatively, press E to exit the greeting without sending an anonymous
   message. An example of the greeting page is shown below:

   The main menu is then presented, which can be navigated using the cursor
   keys. This main menu provides shortcuts for the composing new mails,
   browsing mail directories, and administering address book entries. Below
   the main menu, relevant keyboard shortcuts to perform functions specific
   to the task at hand are shown.

   The default directory opened by alpine is inbox. To view the message
   index, press I, or select the MESSAGE INDEX option shown below:

   The message index shows messages in the current directory and can be
   navigated by using the cursor keys. Highlighted messages can be read by
   pressing Enter.

   In the screenshot below, a sample message is displayed by alpine.
   Contextual keyboard shortcuts are displayed at the bottom of the screen.
   An example of one of a shortcut is r, which tells the MUA to reply to the
   current message being displayed.

   Replying to an email in alpine is done using the pico editor, which is
   installed by default with alpine. pico makes it easy to navigate the
   message and is easier for novice users to use than vi(1) or mail(1). Once
   the reply is complete, the message can be sent by pressing Ctrl+X. alpine
   will ask for confirmation before sending the message.

   alpine can be customized using the SETUP option from the main menu.
   Consult http://www.washington.edu/alpine/ for more information.

29.11. Using fetchmail

   Contributed by Marc Silver.

   fetchmail is a full-featured IMAP and POP client. It allows users to
   automatically download mail from remote IMAP and POP servers and save it
   into local mailboxes where it can be accessed more easily. fetchmail can
   be installed using the mail/fetchmail port, and offers various features,
   including:

     * Support for the POP3, APOP, KPOP, IMAP, ETRN and ODMR protocols.

     * Ability to forward mail using SMTP, which allows filtering,
       forwarding, and aliasing to function normally.

     * May be run in daemon mode to check periodically for new messages.

     * Can retrieve multiple mailboxes and forward them, based on
       configuration, to different local users.

   This section explains some of the basic features of fetchmail. This
   utility requires a .fetchmailrc configuration in the user's home directory
   in order to run correctly. This file includes server information as well
   as login credentials. Due to the sensitive nature of the contents of this
   file, it is advisable to make it readable only by the user, with the
   following command:

 % chmod 600 .fetchmailrc

   The following .fetchmailrc serves as an example for downloading a single
   user mailbox using POP. It tells fetchmail to connect to example.com using
   a username of joesoap and a password of XXX. This example assumes that the
   user joesoap exists on the local system.

 poll example.com protocol pop3 username "joesoap" password "XXX"

   The next example connects to multiple POP and IMAP servers and redirects
   to different local usernames where applicable:

 poll example.com proto pop3:
 user "joesoap", with password "XXX", is "jsoap" here;
 user "andrea", with password "XXXX";
 poll example2.net proto imap:
 user "john", with password "XXXXX", is "myth" here;

   fetchmail can be run in daemon mode by running it with -d, followed by the
   interval (in seconds) that fetchmail should poll servers listed in
   .fetchmailrc. The following example configures fetchmail to poll every 600
   seconds:

 % fetchmail -d 600

   More information on fetchmail can be found at http://www.fetchmail.info/.

29.12. Using procmail

   Contributed by Marc Silver.

   procmail is a powerful application used to filter incoming mail. It allows
   users to define "rules" which can be matched to incoming mails to perform
   specific functions or to reroute mail to alternative mailboxes or email
   addresses. procmail can be installed using the mail/procmail port. Once
   installed, it can be directly integrated into most MTAs. Consult the MTA
   documentation for more information. Alternatively, procmail can be
   integrated by adding the following line to a .forward in the home
   directory of the user:

 "|exec /usr/local/bin/procmail || exit 75"

   The following section displays some basic procmail rules, as well as brief
   descriptions of what they do. Rules must be inserted into a .procmailrc,
   which must reside in the user's home directory.

   The majority of these rules can be found in procmailex(5).

   To forward all mail from <user@example.com> to an external address of
   <goodmail@example2.com>:

 :0
 * ^From.*user@example.com
 ! goodmail@example2.com

   To forward all mails shorter than 1000 bytes to an external address of
   <goodmail@example2.com>:

 :0
 * < 1000
 ! goodmail@example2.com

   To send all mail sent to <alternate@example.com> to a mailbox called
   alternate:

 :0
 * ^TOalternate@example.com
 alternate

   To send all mail with a subject of "Spam" to /dev/null:

 :0
 ^Subject:.*Spam
 /dev/null

   A useful recipe that parses incoming FreeBSD.org mailing lists and places
   each list in its own mailbox:

 :0
 * ^Sender:.owner-freebsd-\/[^@]+@FreeBSD.ORG
 {
         LISTNAME=${MATCH}
         :0
         * LISTNAME??^\/[^@]+
         FreeBSD-${MATCH}
 }

Chapter 30. Network Servers

   Table of Contents

   30.1. Synopsis

   30.2. The inetd Super-Server

   30.3. Network File System (NFS)

   30.4. Network Information System (NIS)

   30.5. Lightweight Directory Access Protocol (LDAP)

   30.6. Dynamic Host Configuration Protocol (DHCP)

   30.7. Domain Name System (DNS)

   30.8. Apache HTTP Server

   30.9. File Transfer Protocol (FTP)

   30.10. File and Print Services for Microsoft(R) Windows(R) Clients (Samba)

   30.11. Clock Synchronization with NTP

   30.12. iSCSI Initiator and Target Configuration

30.1. Synopsis

   This chapter covers some of the more frequently used network services on
   UNIX(R) systems. This includes installing, configuring, testing, and
   maintaining many different types of network services. Example
   configuration files are included throughout this chapter for reference.

   By the end of this chapter, readers will know:

     * How to manage the inetd daemon.

     * How to set up the Network File System (NFS).

     * How to set up the Network Information Server (NIS) for centralizing
       and sharing user accounts.

     * How to set FreeBSD up to act as an LDAP server or client

     * How to set up automatic network settings using DHCP.

     * How to set up a Domain Name Server (DNS).

     * How to set up the Apache HTTP Server.

     * How to set up a File Transfer Protocol (FTP) server.

     * How to set up a file and print server for Windows(R) clients using
       Samba.

     * How to synchronize the time and date, and set up a time server using
       the Network Time Protocol (NTP).

     * How to set up iSCSI.

   This chapter assumes a basic knowledge of:

     * /etc/rc scripts.

     * Network terminology.

     * Installation of additional third-party software (Chapter 4, Installing
       Applications: Packages and Ports).

30.2. The inetd Super-Server

   The inetd(8) daemon is sometimes referred to as a Super-Server because it
   manages connections for many services. Instead of starting multiple
   applications, only the inetd service needs to be started. When a
   connection is received for a service that is managed by inetd, it
   determines which program the connection is destined for, spawns a process
   for that program, and delegates the program a socket. Using inetd for
   services that are not heavily used can reduce system load, when compared
   to running each daemon individually in stand-alone mode.

   Primarily, inetd is used to spawn other daemons, but several trivial
   protocols are handled internally, such as chargen, auth, time, echo,
   discard, and daytime.

   This section covers the basics of configuring inetd.

  30.2.1. Configuration File

   Configuration of inetd is done by editing /etc/inetd.conf. Each line of
   this configuration file represents an application which can be started by
   inetd. By default, every line starts with a comment (#), meaning that
   inetd is not listening for any applications. To configure inetd to listen
   for an application's connections, remove the # at the beginning of the
   line for that application.

   After saving your edits, configure inetd to start at system boot by
   editing /etc/rc.conf:

 inetd_enable="YES"

   To start inetd now, so that it listens for the service you configured,
   type:

 # service inetd start

   Once inetd is started, it needs to be notified whenever a modification is
   made to /etc/inetd.conf:

   Example 30.1. Reloading the inetd Configuration File

 # service inetd reload

   Typically, the default entry for an application does not need to be edited
   beyond removing the #. In some situations, it may be appropriate to edit
   the default entry.

   As an example, this is the default entry for ftpd(8) over IPv4:

 ftp     stream  tcp     nowait  root    /usr/libexec/ftpd       ftpd -l

   The seven columns in an entry are as follows:

 service-name
 socket-type
 protocol
 {wait|nowait}[/max-child[/max-connections-per-ip-per-minute[/max-child-per-ip]]]
 user[:group][/login-class]
 server-program
 server-program-arguments

   where:

   service-name

           The service name of the daemon to start. It must correspond to a
           service listed in /etc/services. This determines which port inetd
           listens on for incoming connections to that service. When using a
           custom service, it must first be added to /etc/services.

   socket-type

           Either stream, dgram, raw, or seqpacket. Use stream for TCP
           connections and dgram for UDP services.

   protocol

           Use one of the following protocol names:

                  Protocol Name                      Explanation              
           tcp or tcp4                  TCP IPv4                              
           udp or udp4                  UDP IPv4                              
           tcp6                         TCP IPv6                              
           udp6                         UDP IPv6                              
           tcp46                        Both TCP IPv4 and IPv6                
           udp46                        Both UDP IPv4 and IPv6                

   {wait|nowait}[/max-child[/max-connections-per-ip-per-minute[/max-child-per-ip]]]

           In this field, wait or nowait must be specified. max-child,
           max-connections-per-ip-per-minute and max-child-per-ip are
           optional.

           wait|nowait indicates whether or not the service is able to handle
           its own socket. dgram socket types must use wait while stream
           daemons, which are usually multi-threaded, should use nowait. wait
           usually hands off multiple sockets to a single daemon, while
           nowait spawns a child daemon for each new socket.

           The maximum number of child daemons inetd may spawn is set by
           max-child. For example, to limit ten instances of the daemon,
           place a /10 after nowait. Specifying /0 allows an unlimited number
           of children.

           max-connections-per-ip-per-minute limits the number of connections
           from any particular IP address per minute. Once the limit is
           reached, further connections from this IP address will be dropped
           until the end of the minute. For example, a value of /10 would
           limit any particular IP address to ten connection attempts per
           minute. max-child-per-ip limits the number of child processes that
           can be started on behalf on any single IP address at any moment.
           These options can limit excessive resource consumption and help to
           prevent Denial of Service attacks.

           An example can be seen in the default settings for fingerd(8):

 finger stream  tcp     nowait/3/10 nobody /usr/libexec/fingerd fingerd -k -s

   user

           The username the daemon will run as. Daemons typically run as
           root, daemon, or nobody.

   server-program

           The full path to the daemon. If the daemon is a service provided
           by inetd internally, use internal.

   server-program-arguments

           Used to specify any command arguments to be passed to the daemon
           on invocation. If the daemon is an internal service, use internal.

  30.2.2. Command-Line Options

   Like most server daemons, inetd has a number of options that can be used
   to modify its behavior. By default, inetd is started with -wW -C 60. These
   options enable TCP wrappers for all services, including internal services,
   and prevent any IP address from requesting any service more than 60 times
   per minute.

   To change the default options which are passed to inetd, add an entry for
   inetd_flags in /etc/rc.conf. If inetd is already running, restart it with
   service inetd restart.

   The available rate limiting options are:

   -c maximum

           Specify the default maximum number of simultaneous invocations of
           each service, where the default is unlimited. May be overridden on
           a per-service basis by using max-child in /etc/inetd.conf.

   -C rate

           Specify the default maximum number of times a service can be
           invoked from a single IP address per minute. May be overridden on
           a per-service basis by using max-connections-per-ip-per-minute in
           /etc/inetd.conf.

   -R rate

           Specify the maximum number of times a service can be invoked in
           one minute, where the default is 256. A rate of 0 allows an
           unlimited number.

   -s maximum

           Specify the maximum number of times a service can be invoked from
           a single IP address at any one time, where the default is
           unlimited. May be overridden on a per-service basis by using
           max-child-per-ip in /etc/inetd.conf.

   Additional options are available. Refer to inetd(8) for the full list of
   options.

  30.2.3. Security Considerations

   Many of the daemons which can be managed by inetd are not
   security-conscious. Some daemons, such as fingerd, can provide information
   that may be useful to an attacker. Only enable the services which are
   needed and monitor the system for excessive connection attempts.
   max-connections-per-ip-per-minute, max-child and max-child-per-ip can be
   used to limit such attacks.

   By default, TCP wrappers is enabled. Consult hosts_access(5) for more
   information on placing TCP restrictions on various inetd invoked daemons.

30.3. Network File System (NFS)

   Reorganized and enhanced by Tom Rhodes.
   Written by Bill Swingle.

   FreeBSD supports the Network File System (NFS), which allows a server to
   share directories and files with clients over a network. With NFS, users
   and programs can access files on remote systems as if they were stored
   locally.

   NFS has many practical uses. Some of the more common uses include:

     * Data that would otherwise be duplicated on each client can be kept in
       a single location and accessed by clients on the network.

     * Several clients may need access to the /usr/ports/distfiles directory.
       Sharing that directory allows for quick access to the source files
       without having to download them to each client.

     * On large networks, it is often more convenient to configure a central
       NFS server on which all user home directories are stored. Users can
       log into a client anywhere on the network and have access to their
       home directories.

     * Administration of NFS exports is simplified. For example, there is
       only one file system where security or backup policies must be set.

     * Removable media storage devices can be used by other machines on the
       network. This reduces the number of devices throughout the network and
       provides a centralized location to manage their security. It is often
       more convenient to install software on multiple machines from a
       centralized installation media.

   NFS consists of a server and one or more clients. The client remotely
   accesses the data that is stored on the server machine. In order for this
   to function properly, a few processes have to be configured and running.

   These daemons must be running on the server:

   Daemon                             Description                             
   nfsd    The NFS daemon which services requests from NFS clients.           
   mountd  The NFS mount daemon which carries out requests received from      
           nfsd.                                                              
   rpcbind This daemon allows NFS clients to discover which port the NFS      
           server is using.                                                   

   Running nfsiod(8) on the client can improve performance, but is not
   required.

  30.3.1. Configuring the Server

   The file systems which the NFS server will share are specified in
   /etc/exports. Each line in this file specifies a file system to be
   exported, which clients have access to that file system, and any access
   options. When adding entries to this file, each exported file system, its
   properties, and allowed hosts must occur on a single line. If no clients
   are listed in the entry, then any client on the network can mount that
   file system.

   The following /etc/exports entries demonstrate how to export file systems.
   The examples can be modified to match the file systems and client names on
   the reader's network. There are many options that can be used in this
   file, but only a few will be mentioned here. See exports(5) for the full
   list of options.

   This example shows how to export /cdrom to three hosts named alpha, bravo,
   and charlie:

 /cdrom -ro alpha bravo charlie

   The -ro flag makes the file system read-only, preventing clients from
   making any changes to the exported file system. This example assumes that
   the host names are either in DNS or in /etc/hosts. Refer to hosts(5) if
   the network does not have a DNS server.

   The next example exports /home to three clients by IP address. This can be
   useful for networks without DNS or /etc/hosts entries. The -alldirs flag
   allows subdirectories to be mount points. In other words, it will not
   automatically mount the subdirectories, but will permit the client to
   mount the directories that are required as needed.

 /usr/home  -alldirs  10.0.0.2 10.0.0.3 10.0.0.4

   This next example exports /a so that two clients from different domains
   may access that file system. The -maproot=root allows root on the remote
   system to write data on the exported file system as root. If -maproot=root
   is not specified, the client's root user will be mapped to the server's
   nobody account and will be subject to the access limitations defined for
   nobody.

 /a  -maproot=root  host.example.com box.example.org

   A client can only be specified once per file system. For example, if /usr
   is a single file system, these entries would be invalid as both entries
   specify the same host:

 # Invalid when /usr is one file system
 /usr/src   client
 /usr/ports client

   The correct format for this situation is to use one entry:

 /usr/src /usr/ports  client

   The following is an example of a valid export list, where /usr and
   /exports are local file systems:

 # Export src and ports to client01 and client02, but only
 # client01 has root privileges on it
 /usr/src /usr/ports -maproot=root    client01
 /usr/src /usr/ports               client02
 # The client machines have root and can mount anywhere
 # on /exports. Anyone in the world can mount /exports/obj read-only
 /exports -alldirs -maproot=root      client01 client02
 /exports/obj -ro

   To enable the processes required by the NFS server at boot time, add these
   options to /etc/rc.conf:

 rpcbind_enable="YES"
 nfs_server_enable="YES"
 mountd_enable="YES"

   The server can be started now by running this command:

 # service nfsd start

   Whenever the NFS server is started, mountd also starts automatically.
   However, mountd only reads /etc/exports when it is started. To make
   subsequent /etc/exports edits take effect immediately, force mountd to
   reread it:

 # service mountd reload

  30.3.2. Configuring the Client

   To enable NFS clients, set this option in each client's /etc/rc.conf:

 nfs_client_enable="YES"

   Then, run this command on each NFS client:

 # service nfsclient start

   The client now has everything it needs to mount a remote file system. In
   these examples, the server's name is server and the client's name is
   client. To mount /home on server to the /mnt mount point on client:

 # mount server:/home /mnt

   The files and directories in /home will now be available on client, in the
   /mnt directory.

   To mount a remote file system each time the client boots, add it to
   /etc/fstab:

 server:/home    /mnt    nfs     rw      0       0

   Refer to fstab(5) for a description of all available options.

  30.3.3. Locking

   Some applications require file locking to operate correctly. To enable
   locking, add these lines to /etc/rc.conf on both the client and server:

 rpc_lockd_enable="YES"
 rpc_statd_enable="YES"

   Then start the applications:

 # service lockd start
 # service statd start

   If locking is not required on the server, the NFS client can be configured
   to lock locally by including -L when running mount. Refer to mount_nfs(8)
   for further details.

  30.3.4. Automating Mounts with autofs(5)

  Note:

   The autofs(5) automount facility is supported starting with
   FreeBSD 10.1-RELEASE. To use the automounter functionality in older
   versions of FreeBSD, use amd(8) instead. This chapter only describes the
   autofs(5) automounter.

   The autofs(5) facility is a common name for several components that,
   together, allow for automatic mounting of remote and local filesystems
   whenever a file or directory within that file system is accessed. It
   consists of the kernel component, autofs(5), and several userspace
   applications: automount(8), automountd(8) and autounmountd(8). It serves
   as an alternative for amd(8) from previous FreeBSD releases. Amd is still
   provided for backward compatibility purposes, as the two use different map
   format; the one used by autofs is the same as with other SVR4
   automounters, such as the ones in Solaris, MacOS X, and Linux.

   The autofs(5) virtual filesystem is mounted on specified mountpoints by
   automount(8), usually invoked during boot.

   Whenever a process attempts to access file within the autofs(5)
   mountpoint, the kernel will notify automountd(8) daemon and pause the
   triggering process. The automountd(8) daemon will handle kernel requests
   by finding the proper map and mounting the filesystem according to it,
   then signal the kernel to release blocked process. The autounmountd(8)
   daemon automatically unmounts automounted filesystems after some time,
   unless they are still being used.

   The primary autofs configuration file is /etc/auto_master. It assigns
   individual maps to top-level mounts. For an explanation of auto_master and
   the map syntax, refer to auto_master(5).

   There is a special automounter map mounted on /net. When a file is
   accessed within this directory, autofs(5) looks up the corresponding
   remote mount and automatically mounts it. For instance, an attempt to
   access a file within /net/foobar/usr would tell automountd(8) to mount the
   /usr export from the host foobar.

   Example 30.2. Mounting an Export with autofs(5)

   In this example, showmount -e shows the exported file systems that can be
   mounted from the NFS server, foobar:

 % showmount -e foobar
 Exports list on foobar:
 /usr                               10.10.10.0
 /a                                 10.10.10.0
 % cd /net/foobar/usr

   The output from showmount shows /usr as an export. When changing
   directories to /host/foobar/usr, automountd(8) intercepts the request and
   attempts to resolve the hostname foobar. If successful, automountd(8)
   automatically mounts the source export.

   To enable autofs(5) at boot time, add this line to /etc/rc.conf:

 autofs_enable="YES"

   Then autofs(5) can be started by running:

 # service automount start
 # service automountd start
 # service autounmountd start

   The autofs(5) map format is the same as in other operating systems.
   Information about this format from other sources can be useful, like the
   Mac OS X document.

   Consult the automount(8), automountd(8), autounmountd(8), and
   auto_master(5) manual pages for more information.

30.4. Network Information System (NIS)

   Network Information System (NIS) is designed to centralize administration
   of UNIX(R)-like systems such as Solaris(TM), HP-UX, AIX(R), Linux, NetBSD,
   OpenBSD, and FreeBSD. NIS was originally known as Yellow Pages but the
   name was changed due to trademark issues. This is the reason why NIS
   commands begin with yp.

   NIS is a Remote Procedure Call (RPC)-based client/server system that
   allows a group of machines within an NIS domain to share a common set of
   configuration files. This permits a system administrator to set up NIS
   client systems with only minimal configuration data and to add, remove, or
   modify configuration data from a single location.

   FreeBSD uses version 2 of the NIS protocol.

  30.4.1. NIS Terms and Processes

   Table 28.1 summarizes the terms and important processes used by NIS:

   Table 30.1. NIS Terminology

         Term                              Description                        
                    NIS servers and clients share an NIS domain name.         
   NIS domain name  Typically, this name does not have anything to do with    
                    DNS.                                                      
   rpcbind(8)       This service enables RPC and must be running in order to  
                    run an NIS server or act as an NIS client.                
                    This service binds an NIS client to its NIS server. It    
                    will take the NIS domain name and use RPC to connect to   
   ypbind(8)        the server. It is the core of client/server communication 
                    in an NIS environment. If this service is not running on  
                    a client machine, it will not be able to access the NIS   
                    server.                                                   
                    This is the process for the NIS server. If this service   
                    stops running, the server will no longer be able to       
   ypserv(8)        respond to NIS requests so hopefully, there is a slave    
                    server to take over. Some non-FreeBSD clients will not    
                    try to reconnect using a slave server and the ypbind      
                    process may need to be restarted on these clients.        
                    This process only runs on NIS master servers. This daemon 
   rpc.yppasswdd(8) allows NIS clients to change their NIS passwords. If this 
                    daemon is not running, users will have to login to the    
                    NIS master server and change their passwords there.       

  30.4.2. Machine Types

   There are three types of hosts in an NIS environment:

     * NIS master server

       This server acts as a central repository for host configuration
       information and maintains the authoritative copy of the files used by
       all of the NIS clients. The passwd, group, and other various files
       used by NIS clients are stored on the master server. While it is
       possible for one machine to be an NIS master server for more than one
       NIS domain, this type of configuration will not be covered in this
       chapter as it assumes a relatively small-scale NIS environment.

     * NIS slave servers

       NIS slave servers maintain copies of the NIS master's data files in
       order to provide redundancy. Slave servers also help to balance the
       load of the master server as NIS clients always attach to the NIS
       server which responds first.

     * NIS clients

       NIS clients authenticate against the NIS server during log on.

   Information in many files can be shared using NIS. The master.passwd,
   group, and hosts files are commonly shared via NIS. Whenever a process on
   a client needs information that would normally be found in these files
   locally, it makes a query to the NIS server that it is bound to instead.

  30.4.3. Planning Considerations

   This section describes a sample NIS environment which consists of 15
   FreeBSD machines with no centralized point of administration. Each machine
   has its own /etc/passwd and /etc/master.passwd. These files are kept in
   sync with each other only through manual intervention. Currently, when a
   user is added to the lab, the process must be repeated on all 15 machines.

   The configuration of the lab will be as follows:

       Machine name            IP address               Machine role          
   ellington             10.0.0.2               NIS master                    
   coltrane              10.0.0.3               NIS slave                     
   basie                 10.0.0.4               Faculty workstation           
   bird                  10.0.0.5               Client machine                
   cli[1-11]             10.0.0.[6-17]          Other client machines         

   If this is the first time an NIS scheme is being developed, it should be
   thoroughly planned ahead of time. Regardless of network size, several
   decisions need to be made as part of the planning process.

    30.4.3.1. Choosing a NIS Domain Name

   When a client broadcasts its requests for info, it includes the name of
   the NIS domain that it is part of. This is how multiple servers on one
   network can tell which server should answer which request. Think of the
   NIS domain name as the name for a group of hosts.

   Some organizations choose to use their Internet domain name for their NIS
   domain name. This is not recommended as it can cause confusion when trying
   to debug network problems. The NIS domain name should be unique within the
   network and it is helpful if it describes the group of machines it
   represents. For example, the Art department at Acme Inc. might be in the
   "acme-art" NIS domain. This example will use the domain name test-domain.

   However, some non-FreeBSD operating systems require the NIS domain name to
   be the same as the Internet domain name. If one or more machines on the
   network have this restriction, the Internet domain name must be used as
   the NIS domain name.

    30.4.3.2. Physical Server Requirements

   There are several things to keep in mind when choosing a machine to use as
   a NIS server. Since NIS clients depend upon the availability of the
   server, choose a machine that is not rebooted frequently. The NIS server
   should ideally be a stand alone machine whose sole purpose is to be an NIS
   server. If the network is not heavily used, it is acceptable to put the
   NIS server on a machine running other services. However, if the NIS server
   becomes unavailable, it will adversely affect all NIS clients.

  30.4.4. Configuring the NIS Master Server

   The canonical copies of all NIS files are stored on the master server. The
   databases used to store the information are called NIS maps. In FreeBSD,
   these maps are stored in /var/yp/[domainname] where [domainname] is the
   name of the NIS domain. Since multiple domains are supported, it is
   possible to have several directories, one for each domain. Each domain
   will have its own independent set of maps.

   NIS master and slave servers handle all NIS requests through ypserv(8).
   This daemon is responsible for receiving incoming requests from NIS
   clients, translating the requested domain and map name to a path to the
   corresponding database file, and transmitting data from the database back
   to the client.

   Setting up a master NIS server can be relatively straight forward,
   depending on environmental needs. Since FreeBSD provides built-in NIS
   support, it only needs to be enabled by adding the following lines to
   /etc/rc.conf:

 nisdomainname="test-domain"     1
 nis_server_enable="YES"         2
 nis_yppasswdd_enable="YES"      3

   1 This line sets the NIS domain name to test-domain.                       
   2 This automates the start up of the NIS server processes when the system  
     boots.                                                                   
   3 This enables the rpc.yppasswdd(8) daemon so that users can change their  
     NIS password from a client machine.                                      

   Care must be taken in a multi-server domain where the server machines are
   also NIS clients. It is generally a good idea to force the servers to bind
   to themselves rather than allowing them to broadcast bind requests and
   possibly become bound to each other. Strange failure modes can result if
   one server goes down and others are dependent upon it. Eventually, all the
   clients will time out and attempt to bind to other servers, but the delay
   involved can be considerable and the failure mode is still present since
   the servers might bind to each other all over again.

   A server that is also a client can be forced to bind to a particular
   server by adding these additional lines to /etc/rc.conf:

 nis_client_enable="YES"                         1
 nis_client_flags="-S test-domain,server"        2

   1   This enables running client stuff as well.                             
   2   This line sets the NIS domain name to test-domain and bind to itself.  

   After saving the edits, type /etc/netstart to restart the network and
   apply the values defined in /etc/rc.conf. Before initializing the NIS
   maps, start ypserv(8):

 # service ypserv start

    30.4.4.1. Initializing the NIS Maps

   NIS maps are generated from the configuration files in /etc on the NIS
   master, with one exception: /etc/master.passwd. This is to prevent the
   propagation of passwords to all the servers in the NIS domain. Therefore,
   before the NIS maps are initialized, configure the primary password files:

 # cp /etc/master.passwd /var/yp/master.passwd
 # cd /var/yp
 # vi master.passwd

   It is advisable to remove all entries for system accounts as well as any
   user accounts that do not need to be propagated to the NIS clients, such
   as the root and any other administrative accounts.

  Note:

   Ensure that the /var/yp/master.passwd is neither group or world readable
   by setting its permissions to 600.

   After completing this task, initialize the NIS maps. FreeBSD includes the
   ypinit(8) script to do this. When generating maps for the master server,
   include -m and specify the NIS domain name:

 ellington# ypinit -m test-domain
 Server Type: MASTER Domain: test-domain
 Creating an YP server will require that you answer a few questions.
 Questions will all be asked at the beginning of the procedure.
 Do you want this procedure to quit on non-fatal errors? [y/n: n] n
 Ok, please remember to go back and redo manually whatever fails.
 If not, something might not work.
 At this point, we have to construct a list of this domains YP servers.
 rod.darktech.org is already known as master server.
 Please continue to add any slave servers, one per line. When you are
 done with the list, type a <control D>.
 master server   :  ellington
 next host to add:  coltrane
 next host to add:  ^D
 The current list of NIS servers looks like this:
 ellington
 coltrane
 Is this correct?  [y/n: y] y

 [..output from map generation..]

 NIS Map update completed.
 ellington has been setup as an YP master server without any errors.

   This will create /var/yp/Makefile from /var/yp/Makefile.dist. By default,
   this file assumes that the environment has a single NIS server with only
   FreeBSD clients. Since test-domain has a slave server, edit this line in
   /var/yp/Makefile so that it begins with a comment (#):

 NOPUSH = "True"

    30.4.4.2. Adding New Users

   Every time a new user is created, the user account must be added to the
   master NIS server and the NIS maps rebuilt. Until this occurs, the new
   user will not be able to login anywhere except on the NIS master. For
   example, to add the new user jsmith to the test-domain domain, run these
   commands on the master server:

 # pw useradd jsmith
 # cd /var/yp
 # make test-domain

   The user could also be added using adduser jsmith instead of pw useradd
   smith.

  30.4.5. Setting up a NIS Slave Server

   To set up an NIS slave server, log on to the slave server and edit
   /etc/rc.conf as for the master server. Do not generate any NIS maps, as
   these already exist on the master server. When running ypinit on the slave
   server, use -s (for slave) instead of -m (for master). This option
   requires the name of the NIS master in addition to the domain name, as
   seen in this example:

 coltrane# ypinit -s ellington test-domain

 Server Type: SLAVE Domain: test-domain Master: ellington

 Creating an YP server will require that you answer a few questions.
 Questions will all be asked at the beginning of the procedure.

 Do you want this procedure to quit on non-fatal errors? [y/n: n]  n

 Ok, please remember to go back and redo manually whatever fails.
 If not, something might not work.
 There will be no further questions. The remainder of the procedure
 should take a few minutes, to copy the databases from ellington.
 Transferring netgroup...
 ypxfr: Exiting: Map successfully transferred
 Transferring netgroup.byuser...
 ypxfr: Exiting: Map successfully transferred
 Transferring netgroup.byhost...
 ypxfr: Exiting: Map successfully transferred
 Transferring master.passwd.byuid...
 ypxfr: Exiting: Map successfully transferred
 Transferring passwd.byuid...
 ypxfr: Exiting: Map successfully transferred
 Transferring passwd.byname...
 ypxfr: Exiting: Map successfully transferred
 Transferring group.bygid...
 ypxfr: Exiting: Map successfully transferred
 Transferring group.byname...
 ypxfr: Exiting: Map successfully transferred
 Transferring services.byname...
 ypxfr: Exiting: Map successfully transferred
 Transferring rpc.bynumber...
 ypxfr: Exiting: Map successfully transferred
 Transferring rpc.byname...
 ypxfr: Exiting: Map successfully transferred
 Transferring protocols.byname...
 ypxfr: Exiting: Map successfully transferred
 Transferring master.passwd.byname...
 ypxfr: Exiting: Map successfully transferred
 Transferring networks.byname...
 ypxfr: Exiting: Map successfully transferred
 Transferring networks.byaddr...
 ypxfr: Exiting: Map successfully transferred
 Transferring netid.byname...
 ypxfr: Exiting: Map successfully transferred
 Transferring hosts.byaddr...
 ypxfr: Exiting: Map successfully transferred
 Transferring protocols.bynumber...
 ypxfr: Exiting: Map successfully transferred
 Transferring ypservers...
 ypxfr: Exiting: Map successfully transferred
 Transferring hosts.byname...
 ypxfr: Exiting: Map successfully transferred

 coltrane has been setup as an YP slave server without any errors.
 Remember to update map ypservers on ellington.

   This will generate a directory on the slave server called
   /var/yp/test-domain which contains copies of the NIS master server's maps.
   Adding these /etc/crontab entries on each slave server will force the
   slaves to sync their maps with the maps on the master server:

 20      *       *       *       *       root   /usr/libexec/ypxfr passwd.byname
 21      *       *       *       *       root   /usr/libexec/ypxfr passwd.byuid

   These entries are not mandatory because the master server automatically
   attempts to push any map changes to its slaves. However, since clients may
   depend upon the slave server to provide correct password information, it
   is recommended to force frequent password map updates. This is especially
   important on busy networks where map updates might not always complete.

   To finish the configuration, run /etc/netstart on the slave server in
   order to start the NIS services.

  30.4.6. Setting Up an NIS Client

   An NIS client binds to an NIS server using ypbind(8). This daemon
   broadcasts RPC requests on the local network. These requests specify the
   domain name configured on the client. If an NIS server in the same domain
   receives one of the broadcasts, it will respond to ypbind, which will
   record the server's address. If there are several servers available, the
   client will use the address of the first server to respond and will direct
   all of its NIS requests to that server. The client will automatically ping
   the server on a regular basis to make sure it is still available. If it
   fails to receive a reply within a reasonable amount of time, ypbind will
   mark the domain as unbound and begin broadcasting again in the hopes of
   locating another server.

   To configure a FreeBSD machine to be an NIS client:

    1. Edit /etc/rc.conf and add the following lines in order to set the NIS
       domain name and start ypbind(8) during network startup:

 nisdomainname="test-domain"
 nis_client_enable="YES"

    2. To import all possible password entries from the NIS server, use vipw
       to remove all user accounts except one from /etc/master.passwd. When
       removing the accounts, keep in mind that at least one local account
       should remain and this account should be a member of wheel. If there
       is a problem with NIS, this local account can be used to log in
       remotely, become the superuser, and fix the problem. Before saving the
       edits, add the following line to the end of the file:

 +:::::::::

       This line configures the client to provide anyone with a valid account
       in the NIS server's password maps an account on the client. There are
       many ways to configure the NIS client by modifying this line. One
       method is described in Section 30.4.8, "Using Netgroups". For more
       detailed reading, refer to the book Managing NFS and NIS, published by
       O'Reilly Media.

    3. To import all possible group entries from the NIS server, add this
       line to /etc/group:

 +:*::

   To start the NIS client immediately, execute the following commands as the
   superuser:

 # /etc/netstart
 # service ypbind start

   After completing these steps, running ypcat passwd on the client should
   show the server's passwd map.

  30.4.7. NIS Security

   Since RPC is a broadcast-based service, any system running ypbind within
   the same domain can retrieve the contents of the NIS maps. To prevent
   unauthorized transactions, ypserv(8) supports a feature called
   "securenets" which can be used to restrict access to a given set of hosts.
   By default, this information is stored in /var/yp/securenets, unless
   ypserv(8) is started with -p and an alternate path. This file contains
   entries that consist of a network specification and a network mask
   separated by white space. Lines starting with # are considered to be
   comments. A sample securenets might look like this:

 # allow connections from local host -- mandatory
 127.0.0.1     255.255.255.255
 # allow connections from any host
 # on the 192.168.128.0 network
 192.168.128.0 255.255.255.0
 # allow connections from any host
 # between 10.0.0.0 to 10.0.15.255
 # this includes the machines in the testlab
 10.0.0.0      255.255.240.0

   If ypserv(8) receives a request from an address that matches one of these
   rules, it will process the request normally. If the address fails to match
   a rule, the request will be ignored and a warning message will be logged.
   If the securenets does not exist, ypserv will allow connections from any
   host.

   Section 14.4, "TCP Wrapper" is an alternate mechanism for providing access
   control instead of securenets. While either access control mechanism adds
   some security, they are both vulnerable to "IP spoofing" attacks. All
   NIS-related traffic should be blocked at the firewall.

   Servers using securenets may fail to serve legitimate NIS clients with
   archaic TCP/IP implementations. Some of these implementations set all host
   bits to zero when doing broadcasts or fail to observe the subnet mask when
   calculating the broadcast address. While some of these problems can be
   fixed by changing the client configuration, other problems may force the
   retirement of these client systems or the abandonment of securenets.

   The use of TCP Wrapper increases the latency of the NIS server. The
   additional delay may be long enough to cause timeouts in client programs,
   especially in busy networks with slow NIS servers. If one or more clients
   suffer from latency, convert those clients into NIS slave servers and
   force them to bind to themselves.

    30.4.7.1. Barring Some Users

   In this example, the basie system is a faculty workstation within the NIS
   domain. The passwd map on the master NIS server contains accounts for both
   faculty and students. This section demonstrates how to allow faculty
   logins on this system while refusing student logins.

   To prevent specified users from logging on to a system, even if they are
   present in the NIS database, use vipw to add -username with the correct
   number of colons towards the end of /etc/master.passwd on the client,
   where username is the username of a user to bar from logging in. The line
   with the blocked user must be before the + line that allows NIS users. In
   this example, bill is barred from logging on to basie:

 basie# cat /etc/master.passwd
 root:[password]:0:0::0:0:The super-user:/root:/bin/csh
 toor:[password]:0:0::0:0:The other super-user:/root:/bin/sh
 daemon:*:1:1::0:0:Owner of many system processes:/root:/usr/sbin/nologin
 operator:*:2:5::0:0:System &:/:/usr/sbin/nologin
 bin:*:3:7::0:0:Binaries Commands and Source,,,:/:/usr/sbin/nologin
 tty:*:4:65533::0:0:Tty Sandbox:/:/usr/sbin/nologin
 kmem:*:5:65533::0:0:KMem Sandbox:/:/usr/sbin/nologin
 games:*:7:13::0:0:Games pseudo-user:/usr/games:/usr/sbin/nologin
 news:*:8:8::0:0:News Subsystem:/:/usr/sbin/nologin
 man:*:9:9::0:0:Mister Man Pages:/usr/share/man:/usr/sbin/nologin
 bind:*:53:53::0:0:Bind Sandbox:/:/usr/sbin/nologin
 uucp:*:66:66::0:0:UUCP pseudo-user:/var/spool/uucppublic:/usr/libexec/uucp/uucico
 xten:*:67:67::0:0:X-10 daemon:/usr/local/xten:/usr/sbin/nologin
 pop:*:68:6::0:0:Post Office Owner:/nonexistent:/usr/sbin/nologin
 nobody:*:65534:65534::0:0:Unprivileged user:/nonexistent:/usr/sbin/nologin
 -bill:::::::::
 +:::::::::

 basie#

  30.4.8. Using Netgroups

   Barring specified users from logging on to individual systems becomes
   unscaleable on larger networks and quickly loses the main benefit of NIS:
   centralized administration.

   Netgroups were developed to handle large, complex networks with hundreds
   of users and machines. Their use is comparable to UNIX(R) groups, where
   the main difference is the lack of a numeric ID and the ability to define
   a netgroup by including both user accounts and other netgroups.

   To expand on the example used in this chapter, the NIS domain will be
   extended to add the users and systems shown in Tables 28.2 and 28.3:

   Table 30.2. Additional Users

               User Name(s)                          Description              
   alpha, beta                           IT department employees              
   charlie, delta                        IT department apprentices            
   echo, foxtrott, golf, ...             employees                            
   able, baker, ...                      interns                              

   Table 30.3. Additional Systems

          Machine Name(s)                        Description                  
   war, death, famine, pollution Only IT employees are allowed to log onto    
                                 these servers.                               
   pride, greed, envy, wrath,    All members of the IT department are allowed 
   lust, sloth                   to login onto these servers.                 
   one, two, three, four, ...    Ordinary workstations used by employees.     
                                 A very old machine without any critical      
   trashcan                      data. Even interns are allowed to use this   
                                 system.                                      

   When using netgroups to configure this scenario, each user is assigned to
   one or more netgroups and logins are then allowed or forbidden for all
   members of the netgroup. When adding a new machine, login restrictions
   must be defined for all netgroups. When a new user is added, the account
   must be added to one or more netgroups. If the NIS setup is planned
   carefully, only one central configuration file needs modification to grant
   or deny access to machines.

   The first step is the initialization of the NIS netgroup map. In FreeBSD,
   this map is not created by default. On the NIS master server, use an
   editor to create a map named /var/yp/netgroup.

   This example creates four netgroups to represent IT employees, IT
   apprentices, employees, and interns:

 IT_EMP  (,alpha,test-domain)    (,beta,test-domain)
 IT_APP  (,charlie,test-domain)  (,delta,test-domain)
 USERS   (,echo,test-domain)     (,foxtrott,test-domain) \
         (,golf,test-domain)
 INTERNS (,able,test-domain)     (,baker,test-domain)

   Each entry configures a netgroup. The first column in an entry is the name
   of the netgroup. Each set of brackets represents either a group of one or
   more users or the name of another netgroup. When specifying a user, the
   three comma-delimited fields inside each group represent:

    1. The name of the host(s) where the other fields representing the user
       are valid. If a hostname is not specified, the entry is valid on all
       hosts.

    2. The name of the account that belongs to this netgroup.

    3. The NIS domain for the account. Accounts may be imported from other
       NIS domains into a netgroup.

   If a group contains multiple users, separate each user with whitespace.
   Additionally, each field may contain wildcards. See netgroup(5) for
   details.

   Netgroup names longer than 8 characters should not be used. The names are
   case sensitive and using capital letters for netgroup names is an easy way
   to distinguish between user, machine and netgroup names.

   Some non-FreeBSD NIS clients cannot handle netgroups containing more than
   15 entries. This limit may be circumvented by creating several
   sub-netgroups with 15 users or fewer and a real netgroup consisting of the
   sub-netgroups, as seen in this example:

 BIGGRP1  (,joe1,domain)  (,joe2,domain)  (,joe3,domain) [...]
 BIGGRP2  (,joe16,domain)  (,joe17,domain) [...]
 BIGGRP3  (,joe31,domain)  (,joe32,domain)
 BIGGROUP  BIGGRP1 BIGGRP2 BIGGRP3

   Repeat this process if more than 225 (15 times 15) users exist within a
   single netgroup.

   To activate and distribute the new NIS map:

 ellington# cd /var/yp
 ellington# make

   This will generate the three NIS maps netgroup, netgroup.byhost and
   netgroup.byuser. Use the map key option of ypcat(1) to check if the new
   NIS maps are available:

 ellington% ypcat -k netgroup
 ellington% ypcat -k netgroup.byhost
 ellington% ypcat -k netgroup.byuser

   The output of the first command should resemble the contents of
   /var/yp/netgroup. The second command only produces output if host-specific
   netgroups were created. The third command is used to get the list of
   netgroups for a user.

   To configure a client, use vipw(8) to specify the name of the netgroup.
   For example, on the server named war, replace this line:

 +:::::::::

   with

 +@IT_EMP:::::::::

   This specifies that only the users defined in the netgroup IT_EMP will be
   imported into this system's password database and only those users are
   allowed to login to this system.

   This configuration also applies to the ~ function of the shell and all
   routines which convert between user names and numerical user IDs. In other
   words, cd ~user will not work, ls -l will show the numerical ID instead of
   the username, and find . -user joe -print will fail with the message No
   such user. To fix this, import all user entries without allowing them to
   login into the servers. This can be achieved by adding an extra line:

 +:::::::::/usr/sbin/nologin

   This line configures the client to import all entries but to replace the
   shell in those entries with /usr/sbin/nologin.

   Make sure that extra line is placed after +@IT_EMP:::::::::. Otherwise,
   all user accounts imported from NIS will have /usr/sbin/nologin as their
   login shell and no one will be able to login to the system.

   To configure the less important servers, replace the old +::::::::: on the
   servers with these lines:

 +@IT_EMP:::::::::
 +@IT_APP:::::::::
 +:::::::::/usr/sbin/nologin

   The corresponding lines for the workstations would be:

 +@IT_EMP:::::::::
 +@USERS:::::::::
 +:::::::::/usr/sbin/nologin

   NIS supports the creation of netgroups from other netgroups which can be
   useful if the policy regarding user access changes. One possibility is the
   creation of role-based netgroups. For example, one might create a netgroup
   called BIGSRV to define the login restrictions for the important servers,
   another netgroup called SMALLSRV for the less important servers, and a
   third netgroup called USERBOX for the workstations. Each of these
   netgroups contains the netgroups that are allowed to login onto these
   machines. The new entries for the NIS netgroup map would look like this:

 BIGSRV    IT_EMP  IT_APP
 SMALLSRV  IT_EMP  IT_APP  ITINTERN
 USERBOX   IT_EMP  ITINTERN USERS

   This method of defining login restrictions works reasonably well when it
   is possible to define groups of machines with identical restrictions.
   Unfortunately, this is the exception and not the rule. Most of the time,
   the ability to define login restrictions on a per-machine basis is
   required.

   Machine-specific netgroup definitions are another possibility to deal with
   the policy changes. In this scenario, the /etc/master.passwd of each
   system contains two lines starting with "+". The first line adds a
   netgroup with the accounts allowed to login onto this machine and the
   second line adds all other accounts with /usr/sbin/nologin as shell. It is
   recommended to use the "ALL-CAPS" version of the hostname as the name of
   the netgroup:

 +@BOXNAME:::::::::
 +:::::::::/usr/sbin/nologin

   Once this task is completed on all the machines, there is no longer a need
   to modify the local versions of /etc/master.passwd ever again. All further
   changes can be handled by modifying the NIS map. Here is an example of a
   possible netgroup map for this scenario:

 # Define groups of users first
 IT_EMP    (,alpha,test-domain)    (,beta,test-domain)
 IT_APP    (,charlie,test-domain)  (,delta,test-domain)
 DEPT1     (,echo,test-domain)     (,foxtrott,test-domain)
 DEPT2     (,golf,test-domain)     (,hotel,test-domain)
 DEPT3     (,india,test-domain)    (,juliet,test-domain)
 ITINTERN  (,kilo,test-domain)     (,lima,test-domain)
 D_INTERNS (,able,test-domain)     (,baker,test-domain)
 #
 # Now, define some groups based on roles
 USERS     DEPT1   DEPT2     DEPT3
 BIGSRV    IT_EMP  IT_APP
 SMALLSRV  IT_EMP  IT_APP    ITINTERN
 USERBOX   IT_EMP  ITINTERN  USERS
 #
 # And a groups for a special tasks
 # Allow echo and golf to access our anti-virus-machine
 SECURITY  IT_EMP  (,echo,test-domain)  (,golf,test-domain)
 #
 # machine-based netgroups
 # Our main servers
 WAR       BIGSRV
 FAMINE    BIGSRV
 # User india needs access to this server
 POLLUTION  BIGSRV  (,india,test-domain)
 #
 # This one is really important and needs more access restrictions
 DEATH     IT_EMP
 #
 # The anti-virus-machine mentioned above
 ONE       SECURITY
 #
 # Restrict a machine to a single user
 TWO       (,hotel,test-domain)
 # [...more groups to follow]

   It may not always be advisable to use machine-based netgroups. When
   deploying a couple of dozen or hundreds of systems, role-based netgroups
   instead of machine-based netgroups may be used to keep the size of the NIS
   map within reasonable limits.

  30.4.9. Password Formats

   NIS requires that all hosts within an NIS domain use the same format for
   encrypting passwords. If users have trouble authenticating on an NIS
   client, it may be due to a differing password format. In a heterogeneous
   network, the format must be supported by all operating systems, where DES
   is the lowest common standard.

   To check which format a server or client is using, look at this section of
   /etc/login.conf:

 default:\
         :passwd_format=des:\
         :copyright=/etc/COPYRIGHT:\
         [Further entries elided]

   In this example, the system is using the DES format. Other possible values
   are blf for Blowfish and md5 for MD5 encrypted passwords.

   If the format on a host needs to be edited to match the one being used in
   the NIS domain, the login capability database must be rebuilt after saving
   the change:

 # cap_mkdb /etc/login.conf

  Note:

   The format of passwords for existing user accounts will not be updated
   until each user changes their password after the login capability database
   is rebuilt.

30.5. Lightweight Directory Access Protocol (LDAP)

   Originally contributed by Tom Rhodes.
   Updates by Rocky Hotas.

   The Lightweight Directory Access Protocol (LDAP) is an application layer
   protocol used to access, modify, and authenticate objects using a
   distributed directory information service. Think of it as a phone or
   record book which stores several levels of hierarchical, homogeneous
   information. It is used in Active Directory and OpenLDAP networks and
   allows users to access to several levels of internal information utilizing
   a single account. For example, email authentication, pulling employee
   contact information, and internal website authentication might all make
   use of a single user account in the LDAP server's record base.

   This section provides a quick start guide for configuring an LDAP server
   on a FreeBSD system. It assumes that the administrator already has a
   design plan which includes the type of information to store, what that
   information will be used for, which users should have access to that
   information, and how to secure this information from unauthorized access.

  30.5.1. LDAP Terminology and Structure

   LDAP uses several terms which should be understood before starting the
   configuration. All directory entries consist of a group of attributes.
   Each of these attribute sets contains a unique identifier known as a
   Distinguished Name (DN) which is normally built from several other
   attributes such as the common or Relative Distinguished Name (RDN).
   Similar to how directories have absolute and relative paths, consider a DN
   as an absolute path and the RDN as the relative path.

   An example LDAP entry looks like the following. This example searches for
   the entry for the specified user account (uid), organizational unit (ou),
   and organization (o):

 % ldapsearch -xb "uid=trhodes,ou=users,o=example.com"
 # extended LDIF
 #
 # LDAPv3
 # base <uid=trhodes,ou=users,o=example.com> with scope subtree
 # filter: (objectclass=*)
 # requesting: ALL
 #

 # trhodes, users, example.com
 dn: uid=trhodes,ou=users,o=example.com
 mail: trhodes@example.com
 cn: Tom Rhodes
 uid: trhodes
 telephoneNumber: (123) 456-7890

 # search result
 search: 2
 result: 0 Success

 # numResponses: 2
 # numEntries: 1

   This example entry shows the values for the dn, mail, cn, uid, and
   telephoneNumber attributes. The cn attribute is the RDN.

   More information about LDAP and its terminology can be found at
   http://www.openldap.org/doc/admin24/intro.html.

  30.5.2. Configuring an LDAP Server

   FreeBSD does not provide a built-in LDAP server. Begin the configuration
   by installing net/openldap-server package or port:

 # pkg install openldap-server

   There is a large set of default options enabled in the package. Review
   them by running pkg info openldap-server. If they are not sufficient (for
   example if SQL support is needed), please consider recompiling the port
   using the appropriate framework.

   The installation creates the directory /var/db/openldap-data to hold the
   data. The directory to store the certificates must be created:

 # mkdir /usr/local/etc/openldap/private

   The next phase is to configure the Certificate Authority. The following
   commands must be executed from /usr/local/etc/openldap/private. This is
   important as the file permissions need to be restrictive and users should
   not have access to these files. More detailed information about
   certificates and their parameters can be found in Section 14.6, "OpenSSL".
   To create the Certificate Authority, start with this command and follow
   the prompts:

 # openssl req -days 365 -nodes -new -x509 -keyout ca.key -out ../ca.crt

   The entries for the prompts may be generic except for the Common Name.
   This entry must be different than the system hostname. If this will be a
   self signed certificate, prefix the hostname with CA for Certificate
   Authority.

   The next task is to create a certificate signing request and a private
   key. Input this command and follow the prompts:

 # openssl req -days 365 -nodes -new -keyout server.key -out server.csr

   During the certificate generation process, be sure to correctly set the
   Common Name attribute. The Certificate Signing Request must be signed with
   the Certificate Authority in order to be used as a valid certificate:

 # openssl x509 -req -days 365 -in server.csr -out ../server.crt -CA ../ca.crt -CAkey ca.key -CAcreateserial

   The final part of the certificate generation process is to generate and
   sign the client certificates:

 # openssl req -days 365 -nodes -new -keyout client.key -out client.csr
 # openssl x509 -req -days 3650 -in client.csr -out ../client.crt -CA ../ca.crt -CAkey ca.key

   Remember to use the same Common Name attribute when prompted. When
   finished, ensure that a total of eight (8) new files have been generated
   through the proceeding commands.

   The daemon running the OpenLDAP server is slapd. Its configuration is
   performed through slapd.ldif: the old slapd.conf has been deprecated by
   OpenLDAP.

   Configuration examples for slapd.ldif are available and can also be found
   in /usr/local/etc/openldap/slapd.ldif.sample. Options are documented in
   slapd-config(5). Each section of slapd.ldif, like all the other LDAP
   attribute sets, is uniquely identified through a DN. Be sure that no blank
   lines are left between the dn: statement and the desired end of the
   section. In the following example, TLS will be used to implement a secure
   channel. The first section represents the global configuration:

 #
 # See slapd-config(5) for details on configuration options.
 # This file should NOT be world readable.
 #
 dn: cn=config
 objectClass: olcGlobal
 cn: config
 #
 #
 # Define global ACLs to disable default read access.
 #
 olcArgsFile: /var/run/openldap/slapd.args
 olcPidFile: /var/run/openldap/slapd.pid
 olcTLSCertificateFile: /usr/local/etc/openldap/server.crt
 olcTLSCertificateKeyFile: /usr/local/etc/openldap/private/server.key
 olcTLSCACertificateFile: /usr/local/etc/openldap/ca.crt
 #olcTLSCipherSuite: HIGH
 olcTLSProtocolMin: 3.1
 olcTLSVerifyClient: never

   The Certificate Authority, server certificate and server private key files
   must be specified here. It is recommended to let the clients choose the
   security cipher and omit option olcTLSCipherSuite (incompatible with TLS
   clients other than openssl). Option olcTLSProtocolMin lets the server
   require a minimum security level: it is recommended. While verification is
   mandatory for the server, it is not for the client: olcTLSVerifyClient:
   never.

   The second section is about the backend modules and can be configured as
   follows:

 #
 # Load dynamic backend modules:
 #
 dn: cn=module,cn=config
 objectClass: olcModuleList
 cn: module
 olcModulepath:  /usr/local/libexec/openldap
 olcModuleload:  back_mdb.la
 #olcModuleload: back_bdb.la
 #olcModuleload: back_hdb.la
 #olcModuleload: back_ldap.la
 #olcModuleload: back_passwd.la
 #olcModuleload: back_shell.la

   The third section is devoted to load the needed ldif schemas to be used by
   the databases: they are essential.

 dn: cn=schema,cn=config
 objectClass: olcSchemaConfig
 cn: schema

 include: file:///usr/local/etc/openldap/schema/core.ldif
 include: file:///usr/local/etc/openldap/schema/cosine.ldif
 include: file:///usr/local/etc/openldap/schema/inetorgperson.ldif
 include: file:///usr/local/etc/openldap/schema/nis.ldif

   Next, the frontend configuration section:

 # Frontend settings
 #
 dn: olcDatabase={-1}frontend,cn=config
 objectClass: olcDatabaseConfig
 objectClass: olcFrontendConfig
 olcDatabase: {-1}frontend
 olcAccess: to * by * read
 #
 # Sample global access control policy:
 #       Root DSE: allow anyone to read it
 #       Subschema (sub)entry DSE: allow anyone to read it
 #       Other DSEs:
 #               Allow self write access
 #               Allow authenticated users read access
 #               Allow anonymous users to authenticate
 #
 #olcAccess: to dn.base="" by * read
 #olcAccess: to dn.base="cn=Subschema" by * read
 #olcAccess: to *
 #       by self write
 #       by users read
 #       by anonymous auth
 #
 # if no access controls are present, the default policy
 # allows anyone and everyone to read anything but restricts
 # updates to rootdn.  (e.g., "access to * by * read")
 #
 # rootdn can always read and write EVERYTHING!
 #
 olcPasswordHash: {SSHA}
 # {SSHA} is already the default for olcPasswordHash

   Another section is devoted to the configuration backend, the only way to
   later access the OpenLDAP server configuration is as a global super-user.

 dn: olcDatabase={0}config,cn=config
 objectClass: olcDatabaseConfig
 olcDatabase: {0}config
 olcAccess: to * by * none
 olcRootPW: {SSHA}iae+lrQZILpiUdf16Z9KmDmSwT77Dj4U

   The default administrator username is cn=config. Type slappasswd in a
   shell, choose a password and use its hash in olcRootPW. If this option is
   not specified now, before slapd.ldif is imported, no one will be later
   able to modify the global configuration section.

   The last section is about the database backend:

 #######################################################################
 # LMDB database definitions
 #######################################################################
 #
 dn: olcDatabase=mdb,cn=config
 objectClass: olcDatabaseConfig
 objectClass: olcMdbConfig
 olcDatabase: mdb
 olcDbMaxSize: 1073741824
 olcSuffix: dc=domain,dc=example
 olcRootDN: cn=mdbadmin,dc=domain,dc=example
 # Cleartext passwords, especially for the rootdn, should
 # be avoided.  See slappasswd(8) and slapd-config(5) for details.
 # Use of strong authentication encouraged.
 olcRootPW: {SSHA}X2wHvIWDk6G76CQyCMS1vDCvtICWgn0+
 # The database directory MUST exist prior to running slapd AND
 # should only be accessible by the slapd and slap tools.
 # Mode 700 recommended.
 olcDbDirectory: /var/db/openldap-data
 # Indices to maintain
 olcDbIndex: objectClass eq

   This database hosts the actual contents of the LDAP directory. Types other
   than mdb are available. Its super-user, not to be confused with the global
   one, is configured here: a (possibly custom) username in olcRootDN and the
   password hash in olcRootPW; slappasswd can be used as before.

   This repository contains four examples of slapd.ldif. To convert an
   existing slapd.conf into slapd.ldif, refer to this page (please note that
   this may introduce some unuseful options).

   When the configuration is completed, slapd.ldif must be placed in an empty
   directory. It is recommended to create it as:

 # mkdir /usr/local/etc/openldap/slapd.d/

   Import the configuration database:

 # /usr/local/sbin/slapadd -n0 -F /usr/local/etc/openldap/slapd.d/ -l /usr/local/etc/openldap/slapd.ldif

   Start the slapd daemon:

 # /usr/local/libexec/slapd -F /usr/local/etc/openldap/slapd.d/

   Option -d can be used for debugging, as specified in slapd(8). To verify
   that the server is running and working:

 # ldapsearch -x -b '' -s base '(objectclass=*)' namingContexts
 # extended LDIF
 #
 # LDAPv3
 # base <> with scope baseObject
 # filter: (objectclass=*)
 # requesting: namingContexts
 #

 #
 dn:
 namingContexts: dc=domain,dc=example

 # search result
 search: 2
 result: 0 Success

 # numResponses: 2
 # numEntries: 1

   The server must still be trusted. If that has never been done before,
   follow these instructions. Install the OpenSSL package or port:

 # pkg install openssl

   From the directory where ca.crt is stored (in this example,
   /usr/local/etc/openldap), run:

 # c_rehash .

   Both the CA and the server certificate are now correctly recognized in
   their respective roles. To verify this, run this command from the
   server.crt directory:

 # openssl verify -verbose -CApath . server.crt

   If slapd was running, restart it. As stated in /usr/local/etc/rc.d/slapd,
   to properly run slapd at boot the following lines must be added to
   /etc/rc.conf:

 lapd_enable="YES"
 slapd_flags='-h "ldapi://%2fvar%2frun%2fopenldap%2fldapi/
 ldap://0.0.0.0/"'
 slapd_sockets="/var/run/openldap/ldapi"
 slapd_cn_config="YES"

   slapd does not provide debugging at boot. Check /var/log/debug.log, dmesg
   -a and /var/log/messages for this purpose.

   The following example adds the group team and the user john to the
   domain.example LDAP database, which is still empty. First, create the file
   domain.ldif:

 # cat domain.ldif
 dn: dc=domain,dc=example
 objectClass: dcObject
 objectClass: organization
 o: domain.example
 dc: domain

 dn: ou=groups,dc=domain,dc=example
 objectClass: top
 objectClass: organizationalunit
 ou: groups

 dn: ou=users,dc=domain,dc=example
 objectClass: top
 objectClass: organizationalunit
 ou: users

 dn: cn=team,ou=groups,dc=domain,dc=example
 objectClass: top
 objectClass: posixGroup
 cn: team
 gidNumber: 10001

 dn: uid=john,ou=users,dc=domain,dc=example
 objectClass: top
 objectClass: account
 objectClass: posixAccount
 objectClass: shadowAccount
 cn: John McUser
 uid: john
 uidNumber: 10001
 gidNumber: 10001
 homeDirectory: /home/john/
 loginShell: /usr/bin/bash
 userPassword: secret

   See the OpenLDAP documentation for more details. Use slappasswd to replace
   the plain text password secret with a hash in userPassword. The path
   specified as loginShell must exist in all the systems where john is
   allowed to login. Finally, use the mdb administrator to modify the
   database:

 # ldapadd -W -D "cn=mdbadmin,dc=domain,dc=example" -f domain.ldif

   Modifications to the global configuration section can only be performed by
   the global super-user. For example, assume that the option
   olcTLSCipherSuite: HIGH:MEDIUM:SSLv3 was initially specified and must now
   be deleted. First, create a file that contains the following:

 # cat global_mod
 dn: cn=config
 changetype: modify
 delete: olcTLSCipherSuite

   Then, apply the modifications:

 # ldapmodify -f global_mod -x -D "cn=config" -W

   When asked, provide the password chosen in the configuration backend
   section. The username is not required: here, cn=config represents the DN
   of the database section to be modified. Alternatively, use ldapmodify to
   delete a single line of the database, ldapdelete to delete a whole entry.

   If something goes wrong, or if the global super-user cannot access the
   configuration backend, it is possible to delete and re-write the whole
   configuration:

 # rm -rf /usr/local/etc/openldap/slapd.d/

   slapd.ldif can then be edited and imported again. Please, follow this
   procedure only when no other solution is available.

   This is the configuration of the server only. The same machine can also
   host an LDAP client, with its own separate configuration.

30.6. Dynamic Host Configuration Protocol (DHCP)

   The Dynamic Host Configuration Protocol (DHCP) allows a system to connect
   to a network in order to be assigned the necessary addressing information
   for communication on that network. FreeBSD includes the OpenBSD version of
   dhclient which is used by the client to obtain the addressing information.
   FreeBSD does not install a DHCP server, but several servers are available
   in the FreeBSD Ports Collection. The DHCP protocol is fully described in
   RFC 2131. Informational resources are also available at
   isc.org/downloads/dhcp/.

   This section describes how to use the built-in DHCP client. It then
   describes how to install and configure a DHCP server.

  Note:

   In FreeBSD, the bpf(4) device is needed by both the DHCP server and DHCP
   client. This device is included in the GENERIC kernel that is installed
   with FreeBSD. Users who prefer to create a custom kernel need to keep this
   device if DHCP is used.

   It should be noted that bpf also allows privileged users to run network
   packet sniffers on that system.

  30.6.1. Configuring a DHCP Client

   DHCP client support is included in the FreeBSD installer, making it easy
   to configure a newly installed system to automatically receive its
   networking addressing information from an existing DHCP server. Refer to
   Section 2.8, "Accounts, Time Zone, Services and Hardening" for examples of
   network configuration.

   When dhclient is executed on the client machine, it begins broadcasting
   requests for configuration information. By default, these requests use UDP
   port 68. The server replies on UDP port 67, giving the client an IP
   address and other relevant network information such as a subnet mask,
   default gateway, and DNS server addresses. This information is in the form
   of a DHCP "lease" and is valid for a configurable time. This allows stale
   IP addresses for clients no longer connected to the network to
   automatically be reused. DHCP clients can obtain a great deal of
   information from the server. An exhaustive list may be found in
   dhcp-options(5).

   By default, when a FreeBSD system boots, its DHCP client runs in the
   background, or asynchronously. Other startup scripts continue to run while
   the DHCP process completes, which speeds up system startup.

   Background DHCP works well when the DHCP server responds quickly to the
   client's requests. However, DHCP may take a long time to complete on some
   systems. If network services attempt to run before DHCP has assigned the
   network addressing information, they will fail. Using DHCP in synchronous
   mode prevents this problem as it pauses startup until the DHCP
   configuration has completed.

   This line in /etc/rc.conf is used to configure background or asynchronous
   mode:

 ifconfig_fxp0="DHCP"

   This line may already exist if the system was configured to use DHCP
   during installation. Replace the fxp0 shown in these examples with the
   name of the interface to be dynamically configured, as described in
   Section 12.5, "Setting Up Network Interface Cards".

   To instead configure the system to use synchronous mode, and to pause
   during startup while DHCP completes, use "SYNCDHCP":

 ifconfig_fxp0="SYNCDHCP"

   Additional client options are available. Search for dhclient in rc.conf(5)
   for details.

   The DHCP client uses the following files:

     * /etc/dhclient.conf

       The configuration file used by dhclient. Typically, this file contains
       only comments as the defaults are suitable for most clients. This
       configuration file is described in dhclient.conf(5).

     * /sbin/dhclient

       More information about the command itself can be found in dhclient(8).

     * /sbin/dhclient-script

       The FreeBSD-specific DHCP client configuration script. It is described
       in dhclient-script(8), but should not need any user modification to
       function properly.

     * /var/db/dhclient.leases.interface

       The DHCP client keeps a database of valid leases in this file, which
       is written as a log and is described in dhclient.leases(5).

  30.6.2. Installing and Configuring a DHCP Server

   This section demonstrates how to configure a FreeBSD system to act as a
   DHCP server using the Internet Systems Consortium (ISC) implementation of
   the DHCP server. This implementation and its documentation can be
   installed using the net/isc-dhcp43-server package or port.

   The installation of net/isc-dhcp43-server installs a sample configuration
   file. Copy /usr/local/etc/dhcpd.conf.example to /usr/local/etc/dhcpd.conf
   and make any edits to this new file.

   The configuration file is comprised of declarations for subnets and hosts
   which define the information that is provided to DHCP clients. For
   example, these lines configure the following:

 option domain-name "example.org";1
 option domain-name-servers ns1.example.org;2
 option subnet-mask 255.255.255.0;3

 default-lease-time 600;4
 max-lease-time 72400;5
 ddns-update-style none;6

 subnet 10.254.239.0 netmask 255.255.255.224 {
   range 10.254.239.10 10.254.239.20;7
   option routers rtr-239-0-1.example.org, rtr-239-0-2.example.org;8
 }

 host fantasia {
   hardware ethernet 08:00:07:26:c0:a5;9
   fixed-address fantasia.fugue.com;10
 }

   1  This option specifies the default search domain that will be provided   
      to clients. Refer to resolv.conf(5) for more information.               
   2  This option specifies a comma separated list of DNS servers that the    
      client should use. They can be listed by their Fully Qualified Domain   
      Names (FQDN), as seen in the example, or by their IP addresses.         
   3  The subnet mask that will be provided to clients.                       
   4  The default lease expiry time in seconds. A client can be configured to 
      override this value.                                                    
   5  The maximum allowed length of time, in seconds, for a lease. Should a   
      client request a longer lease, a lease will still be issued, but it     
      will only be valid for max-lease-time.                                  
   6  The default of none disables dynamic DNS updates. Changing this to      
      interim configures the DHCP server to update a DNS server whenever it   
      hands out a lease so that the DNS server knows which IP addresses are   
      associated with which computers in the network. Do not change the       
      default setting unless the DNS server has been configured to support    
      dynamic DNS.                                                            
   7  This line creates a pool of available IP addresses which are reserved   
      for allocation to DHCP clients. The range of addresses must be valid    
      for the network or subnet specified in the previous line.               
   8  Declares the default gateway that is valid for the network or subnet    
      specified before the opening { bracket.                                 
   9  Specifies the hardware MAC address of a client so that the DHCP server  
      can recognize the client when it makes a request.                       
   10 Specifies that this host should always be given the same IP address.    
      Using the hostname is correct, since the DHCP server will resolve the   
      hostname before returning the lease information.                        

   This configuration file supports many more options. Refer to
   dhcpd.conf(5), installed with the server, for details and examples.

   Once the configuration of dhcpd.conf is complete, enable the DHCP server
   in /etc/rc.conf:

 dhcpd_enable="YES"
 dhcpd_ifaces="dc0"

   Replace the dc0 with the interface (or interfaces, separated by
   whitespace) that the DHCP server should listen on for DHCP client
   requests.

   Start the server by issuing the following command:

 # service isc-dhcpd start

   Any future changes to the configuration of the server will require the
   dhcpd service to be stopped and then started using service(8).

   The DHCP server uses the following files. Note that the manual pages are
   installed with the server software.

     * /usr/local/sbin/dhcpd

       More information about the dhcpd server can be found in dhcpd(8).

     * /usr/local/etc/dhcpd.conf

       The server configuration file needs to contain all the information
       that should be provided to clients, along with information regarding
       the operation of the server. This configuration file is described in
       dhcpd.conf(5).

     * /var/db/dhcpd.leases

       The DHCP server keeps a database of leases it has issued in this file,
       which is written as a log. Refer to dhcpd.leases(5), which gives a
       slightly longer description.

     * /usr/local/sbin/dhcrelay

       This daemon is used in advanced environments where one DHCP server
       forwards a request from a client to another DHCP server on a separate
       network. If this functionality is required, install the
       net/isc-dhcp43-relay package or port. The installation includes
       dhcrelay(8) which provides more detail.

30.7. Domain Name System (DNS)

   Domain Name System (DNS) is the protocol through which domain names are
   mapped to IP addresses, and vice versa. DNS is coordinated across the
   Internet through a somewhat complex system of authoritative root, Top
   Level Domain (TLD), and other smaller-scale name servers, which host and
   cache individual domain information. It is not necessary to run a name
   server to perform DNS lookups on a system.

   The following table describes some of the terms associated with DNS:

   Table 30.4. DNS Terminology

      Term                               Definition                           
   Forward DNS Mapping of hostnames to IP addresses.                          
   Origin      Refers to the domain covered in a particular zone file.        
   Resolver    A system process through which a machine queries a name server 
               for zone information.                                          
   Reverse DNS Mapping of IP addresses to hostnames.                          
               The beginning of the Internet zone hierarchy. All zones fall   
   Root zone   under the root zone, similar to how all files in a file system 
               fall under the root directory.                                 
   Zone        An individual domain, subdomain, or portion of the DNS         
               administered by the same authority.                            

   Examples of zones:

     * . is how the root zone is usually referred to in documentation.

     * org. is a Top Level Domain (TLD) under the root zone.

     * example.org. is a zone under the org. TLD.

     * 1.168.192.in-addr.arpa is a zone referencing all IP addresses which
       fall under the 192.168.1.* IP address space.

   As one can see, the more specific part of a hostname appears to its left.
   For example, example.org. is more specific than org., as org. is more
   specific than the root zone. The layout of each part of a hostname is much
   like a file system: the /dev directory falls within the root, and so on.

  30.7.1. Reasons to Run a Name Server

   Name servers generally come in two forms: authoritative name servers, and
   caching (also known as resolving) name servers.

   An authoritative name server is needed when:

     * One wants to serve DNS information to the world, replying
       authoritatively to queries.

     * A domain, such as example.org, is registered and IP addresses need to
       be assigned to hostnames under it.

     * An IP address block requires reverse DNS entries (IP to hostname).

     * A backup or second name server, called a slave, will reply to queries.

   A caching name server is needed when:

     * A local DNS server may cache and respond more quickly than querying an
       outside name server.

   When one queries for www.FreeBSD.org, the resolver usually queries the
   uplink ISP's name server, and retrieves the reply. With a local, caching
   DNS server, the query only has to be made once to the outside world by the
   caching DNS server. Additional queries will not have to go outside the
   local network, since the information is cached locally.

  30.7.2. DNS Server Configuration

   Unbound is provided in the FreeBSD base system. By default, it will
   provide DNS resolution to the local machine only. While the base system
   package can be configured to provide resolution services beyond the local
   machine, it is recommended that such requirements be addressed by
   installing Unbound from the FreeBSD Ports Collection.

   To enable Unbound, add the following to /etc/rc.conf:

 local_unbound_enable="YES"

   Any existing nameservers in /etc/resolv.conf will be configured as
   forwarders in the new Unbound configuration.

  Note:

   If any of the listed nameservers do not support DNSSEC, local DNS
   resolution will fail. Be sure to test each nameserver and remove any that
   fail the test. The following command will show the trust tree or a failure
   for a nameserver running on 192.168.1.1:

 % drill -S FreeBSD.org @192.168.1.1

   Once each nameserver is confirmed to support DNSSEC, start Unbound:

 # service local_unbound onestart

   This will take care of updating /etc/resolv.conf so that queries for
   DNSSEC secured domains will now work. For example, run the following to
   validate the FreeBSD.org DNSSEC trust tree:

 % drill -S FreeBSD.org
 ;; Number of trusted keys: 1
 ;; Chasing: freebsd.org. A

 DNSSEC Trust tree:
 freebsd.org. (A)
 |---freebsd.org. (DNSKEY keytag: 36786 alg: 8 flags: 256)
     |---freebsd.org. (DNSKEY keytag: 32659 alg: 8 flags: 257)
     |---freebsd.org. (DS keytag: 32659 digest type: 2)
         |---org. (DNSKEY keytag: 49587 alg: 7 flags: 256)
             |---org. (DNSKEY keytag: 9795 alg: 7 flags: 257)
             |---org. (DNSKEY keytag: 21366 alg: 7 flags: 257)
             |---org. (DS keytag: 21366 digest type: 1)
             |   |---. (DNSKEY keytag: 40926 alg: 8 flags: 256)
             |       |---. (DNSKEY keytag: 19036 alg: 8 flags: 257)
             |---org. (DS keytag: 21366 digest type: 2)
                 |---. (DNSKEY keytag: 40926 alg: 8 flags: 256)
                     |---. (DNSKEY keytag: 19036 alg: 8 flags: 257)
 ;; Chase successful

30.8. Apache HTTP Server

   Contributed by Murray Stokely.

   The open source Apache HTTP Server is the most widely used web server.
   FreeBSD does not install this web server by default, but it can be
   installed from the www/apache24 package or port.

   This section summarizes how to configure and start version 2.x of the
   Apache HTTP Server on FreeBSD. For more detailed information about
   Apache 2.X and its configuration directives, refer to httpd.apache.org.

  30.8.1. Configuring and Starting Apache

   In FreeBSD, the main Apache HTTP Server configuration file is installed as
   /usr/local/etc/apache2x/httpd.conf, where x represents the version number.
   This ASCII text file begins comment lines with a #. The most frequently
   modified directives are:

   ServerRoot "/usr/local"

           Specifies the default directory hierarchy for the Apache
           installation. Binaries are stored in the bin and sbin
           subdirectories of the server root and configuration files are
           stored in the etc/apache2x subdirectory.

   ServerAdmin you@example.com

           Change this to the email address to receive problems with the
           server. This address also appears on some server-generated pages,
           such as error documents.

   ServerName www.example.com:80

           Allows an administrator to set a hostname which is sent back to
           clients for the server. For example, www can be used instead of
           the actual hostname. If the system does not have a registered DNS
           name, enter its IP address instead. If the server will listen on
           an alternate report, change 80 to the alternate port number.

   DocumentRoot "/usr/local/www/apache2x/data"

           The directory where documents will be served from. By default, all
           requests are taken from this directory, but symbolic links and
           aliases may be used to point to other locations.

   It is always a good idea to make a backup copy of the default Apache
   configuration file before making changes. When the configuration of Apache
   is complete, save the file and verify the configuration using apachectl.
   Running apachectl configtest should return Syntax OK.

   To launch Apache at system startup, add the following line to
   /etc/rc.conf:

 apache24_enable="YES"

   If Apache should be started with non-default options, the following line
   may be added to /etc/rc.conf to specify the needed flags:

 apache24_flags=""

   If apachectl does not report configuration errors, start httpd now:

 # service apache24 start

   The httpd service can be tested by entering http://localhost in a web
   browser, replacing localhost with the fully-qualified domain name of the
   machine running httpd. The default web page that is displayed is
   /usr/local/www/apache24/data/index.html.

   The Apache configuration can be tested for errors after making subsequent
   configuration changes while httpd is running using the following command:

 # service apache24 configtest

  Note:

   It is important to note that configtest is not an rc(8) standard, and
   should not be expected to work for all startup scripts.

  30.8.2. Virtual Hosting

   Virtual hosting allows multiple websites to run on one Apache server. The
   virtual hosts can be IP-based or name-based. IP-based virtual hosting uses
   a different IP address for each website. Name-based virtual hosting uses
   the clients HTTP/1.1 headers to figure out the hostname, which allows the
   websites to share the same IP address.

   To setup Apache to use name-based virtual hosting, add a VirtualHost block
   for each website. For example, for the webserver named www.domain.tld with
   a virtual domain of www.someotherdomain.tld, add the following entries to
   httpd.conf:

 <VirtualHost *>
     ServerName www.domain.tld
     DocumentRoot /www/domain.tld
 </VirtualHost>

 <VirtualHost *>
     ServerName www.someotherdomain.tld
     DocumentRoot /www/someotherdomain.tld
 </VirtualHost>

   For each virtual host, replace the values for ServerName and DocumentRoot
   with the values to be used.

   For more information about setting up virtual hosts, consult the official
   Apache documentation at: http://httpd.apache.org/docs/vhosts/.

  30.8.3. Apache Modules

   Apache uses modules to augment the functionality provided by the basic
   server. Refer to http://httpd.apache.org/docs/current/mod/ for a complete
   listing of and the configuration details for the available modules.

   In FreeBSD, some modules can be compiled with the www/apache24 port. Type
   make config within /usr/ports/www/apache24 to see which modules are
   available and which are enabled by default. If the module is not compiled
   with the port, the FreeBSD Ports Collection provides an easy way to
   install many modules. This section describes three of the most commonly
   used modules.

    30.8.3.1. SSL support

   At one in point in time, support for SSL inside of Apache required a
   secondary module called mod_ssl. This is no longer the case and the
   default install of Apache comes with SSL built into the web server. An
   example of how to enable support for SSL websites is available in the
   installed file, httpd-ssl.conf inside of the /usr/local/etc/apache24/extra
   directory. Inside this directory is also a sample file called named
   ssl.conf-sample. It is recommended that both files be evaluated to
   properly set up secure websites in the Apache web server.

   After the configuration of SSL is complete, the following line must be
   uncommented in the main http.conf to activate the changes on the next
   restart or reload of Apache:

 #Include etc/apache24/extra/httpd-ssl.conf

  Warning:

   SSL version two and version three have known vulnerability issues. It is
   highly recommended TLS version 1.2 and 1.3 be enabled in place of the
   older SSL options. This can be accomplished by setting the following
   options in the ssl.conf:

 SSLProtocol all -SSLv3 -SSLv2 +TLSv1.2 +TLSv1.3
 SSLProxyProtocol all -SSLv2 -SSLv3 -TLSv1 -TLSv1.1

   To complete the configuration of SSL in the web server, uncomment the
   following line to ensure that the configuration will be pulled into Apache
   during restart or reload:

 # Secure (SSL/TLS) connections
 Include etc/apache24/extra/httpd-ssl.conf

   The following lines must also be uncommented in the httpd.conf to fully
   support SSL in Apache:

 LoadModule authn_socache_module libexec/apache24/mod_authn_socache.so
 LoadModule socache_shmcb_module libexec/apache24/mod_socache_shmcb.so
 LoadModule ssl_module libexec/apache24/mod_ssl.so

   The next step is to work with a certificate authority to have the
   appropriate certificates installed on the system. This will set up a chain
   of trust for the site and prevent any warnings of self-signed
   certificates.

    30.8.3.2. mod_perl

   The mod_perl module makes it possible to write Apache modules in Perl. In
   addition, the persistent interpreter embedded in the server avoids the
   overhead of starting an external interpreter and the penalty of Perl
   start-up time.

   The mod_perl can be installed using the www/mod_perl2 package or port.
   Documentation for using this module can be found at
   http://perl.apache.org/docs/2.0/index.html.

    30.8.3.3. mod_php

   Written by Tom Rhodes.

   PHP: Hypertext Preprocessor (PHP) is a general-purpose scripting language
   that is especially suited for web development. Capable of being embedded
   into HTML, its syntax draws upon C, Java(TM), and Perl with the intention
   of allowing web developers to write dynamically generated webpages
   quickly.

   Support for PHP for Apache and any other feature written in the language,
   can be added by installing the appropriate port.

   For all supported versions, search the package database using pkg:

 # pkg search php

   A list will be displayed including the versions and additional features
   they provide. The components are completely modular, meaning features are
   enabled by installing the appropriate port. To install PHP version 7.4 for
   Apache, issue the following command:

 # pkg install mod_php74

   If any dependency packages need to be installed, they will be installed as
   well.

   By default, PHP will not be enabled. The following lines will need to be
   added to the Apache configuration file located in /usr/local/etc/apache24
   to make it active:

 <FilesMatch "\.php$">
     SetHandler application/x-httpd-php
 </FilesMatch>
 <FilesMatch "\.phps$">
     SetHandler application/x-httpd-php-source
 </FilesMatch>

   In addition, the DirectoryIndex in the configuration file will also need
   to be updated and Apache will either need to be restarted or reloaded for
   the changes to take effect.

   Support for many of the PHP features may also be installed by using pkg.
   For example, to install support for XML or SSL, install their respective
   ports:

 # pkg install php74-xml php74-openssl

   As before, the Apache configuration will need to be reloaded for the
   changes to take effect, even in cases where it was just a module install.

   To perform a graceful restart to reload the configuration, issue the
   following command:

 # apachectl graceful

   Once the install is complete, there are two methods of obtaining the
   installed PHP support modules and the environmental information of the
   build. The first is to install the full PHP binary and running the command
   to gain the information:

 # pkg install php74

 # php -i |less

   It is necessary to pass the output to a pager, such as the more or less to
   easier digest the amount of output.

   Finally, to make any changes to the global configuration of PHP there is a
   well documented file installed into /usr/local/etc/php.ini. At the time of
   install, this file will not exist because there are two versions to choose
   from, one is php.ini-development and the other is php.ini-production.
   These are starting points to assist administrators in their deployment.

    30.8.3.4. HTTP2 Support

   Apache support for the HTTP2 protocol is included by default when
   installing the port with pkg. The new version of HTTP includes many
   improvements over the previous version, including utilizing a single
   connection to a website, reducing overall roundtrips of TCP connections.
   Also, packet header data is compressed and HTTP2 requires encryption by
   default.

   When Apache is configured to only use HTTP2, web browsers will require
   secure, encrypted HTTPS connections. When Apache is configured to use both
   versions, HTTP1.1 will be considered a fall back option if any issues
   arise during the connection.

   While this change does require administrators to make changes, they are
   positive and equate to a more secure Internet for everyone. The changes
   are only required for sites not currently implementing SSL and TLS.

  Note:

   This configuration depends on the previous sections, including TLS
   support. It is recommended those instructions be followed before
   continuing with this configuration.

   Start the process by enabling the http2 module by uncommenting the line in
   /usr/local/etc/apache24/httpd.conf and replace the mpm_prefork module with
   mpm_event as the former does not support HTTP2.

 LoadModule http2_module libexec/apache24/mod_http2.so
 LoadModule mpm_event_module libexec/apache24/mod_mpm_event.so

  Note:

   There is a separate mod_http2 port that is available. It exists to deliver
   security and bug fixes quicker than the module installed with the bundled
   apache24 port. It is not required for HTTP2 support but is available. When
   installed, the mod_h2.so should be used in place of mod_http2.so in the
   Apache configuration.

   There are two methods to implement HTTP2 in Apache; one way is globally
   for all sites and each VirtualHost running on the system. To enable HTTP2
   globally, add the following line under the ServerName directive:

 Protocols h2 http/1.1

  Note:

   To enable HTTP2 over plaintext, use h2 h2c http/1.1 in the httpd.conf.

   Having the h2c here will allow plaintext HTTP2 data to pass on the system
   but is not recommended. In addition, using the http/1.1 here will allow
   fallback to the HTTP1.1 version of the protocol should it be needed by the
   system.

   To enable HTTP2 for individual VirtualHosts, add the same line within the
   VirtualHost directive in either httpd.conf or httpd-ssl.conf.

   Reload the configuration using the apachectl reload command and test the
   configuration either by using either of the following methods after
   visiting one of the hosted pages:

 # grep "HTTP/2.0" /var/log/httpd-access.log

   This should return something similar to the following:

 192.168.1.205 - - [18/Oct/2020:18:34:36 -0400] "GET / HTTP/2.0" 304 -
 192.0.2.205 - - [18/Oct/2020:19:19:57 -0400] "GET / HTTP/2.0" 304 -
 192.0.0.205 - - [18/Oct/2020:19:20:52 -0400] "GET / HTTP/2.0" 304 -
 192.0.2.205 - - [18/Oct/2020:19:23:10 -0400] "GET / HTTP/2.0" 304 -

   The other method is using the web browser's built in site debugger or
   tcpdump; however, using either method is beyond the scope of this
   document.

   Support for HTTP2 reverse proxy connections by using the
   mod_proxy_http2.so module. When configuring the ProxyPass or RewriteRules
   [P] statements, they should use h2:// for the connection.

  30.8.4. Dynamic Websites

   In addition to mod_perl and mod_php, other languages are available for
   creating dynamic web content. These include Django and Ruby on Rails.

    30.8.4.1. Django

   Django is a BSD-licensed framework designed to allow developers to write
   high performance, elegant web applications quickly. It provides an
   object-relational mapper so that data types are developed as Python
   objects. A rich dynamic database-access API is provided for those objects
   without the developer ever having to write SQL. It also provides an
   extensible template system so that the logic of the application is
   separated from the HTML presentation.

   Django depends on mod_python, and an SQL database engine. In FreeBSD, the
   www/py-django port automatically installs mod_python and supports the
   PostgreSQL, MySQL, or SQLite databases, with the default being SQLite. To
   change the database engine, type make config within
   /usr/ports/www/py-django, then install the port.

   Once Django is installed, the application will need a project directory
   along with the Apache configuration in order to use the embedded Python
   interpreter. This interpreter is used to call the application for specific
   URLs on the site.

   To configure Apache to pass requests for certain URLs to the web
   application, add the following to httpd.conf, specifying the full path to
   the project directory:

 <Location "/">
     SetHandler python-program
     PythonPath "['/dir/to/the/django/packages/'] + sys.path"
     PythonHandler django.core.handlers.modpython
     SetEnv DJANGO_SETTINGS_MODULE mysite.settings
     PythonAutoReload On
     PythonDebug On
 </Location>

   Refer to https://docs.djangoproject.com for more information on how to use
   Django.

    30.8.4.2. Ruby on Rails

   Ruby on Rails is another open source web framework that provides a full
   development stack. It is optimized to make web developers more productive
   and capable of writing powerful applications quickly. On FreeBSD, it can
   be installed using the www/rubygem-rails package or port.

   Refer to http://guides.rubyonrails.org for more information on how to use
   Ruby on Rails.

30.9. File Transfer Protocol (FTP)

   The File Transfer Protocol (FTP) provides users with a simple way to
   transfer files to and from an FTP server. FreeBSD includes FTP server
   software, ftpd, in the base system.

   FreeBSD provides several configuration files for controlling access to the
   FTP server. This section summarizes these files. Refer to ftpd(8) for more
   details about the built-in FTP server.

  30.9.1. Configuration

   The most important configuration step is deciding which accounts will be
   allowed access to the FTP server. A FreeBSD system has a number of system
   accounts which should not be allowed FTP access. The list of users
   disallowed any FTP access can be found in /etc/ftpusers. By default, it
   includes system accounts. Additional users that should not be allowed
   access to FTP can be added.

   In some cases it may be desirable to restrict the access of some users
   without preventing them completely from using FTP. This can be
   accomplished be creating /etc/ftpchroot as described in ftpchroot(5). This
   file lists users and groups subject to FTP access restrictions.

   To enable anonymous FTP access to the server, create a user named ftp on
   the FreeBSD system. Users will then be able to log on to the FTP server
   with a username of ftp or anonymous. When prompted for the password, any
   input will be accepted, but by convention, an email address should be used
   as the password. The FTP server will call chroot(2) when an anonymous user
   logs in, to restrict access to only the home directory of the ftp user.

   There are two text files that can be created to specify welcome messages
   to be displayed to FTP clients. The contents of /etc/ftpwelcome will be
   displayed to users before they reach the login prompt. After a successful
   login, the contents of /etc/ftpmotd will be displayed. Note that the path
   to this file is relative to the login environment, so the contents of
   ~ftp/etc/ftpmotd would be displayed for anonymous users.

   Once the FTP server has been configured, set the appropriate variable in
   /etc/rc.conf to start the service during boot:

 ftpd_enable="YES"

   To start the service now:

 # service ftpd start

   Test the connection to the FTP server by typing:

 % ftp localhost

   The ftpd daemon uses syslog(3) to log messages. By default, the system log
   daemon will write messages related to FTP in /var/log/xferlog. The
   location of the FTP log can be modified by changing the following line in
   /etc/syslog.conf:

 ftp.info      /var/log/xferlog

  Note:

   Be aware of the potential problems involved with running an anonymous FTP
   server. In particular, think twice about allowing anonymous users to
   upload files. It may turn out that the FTP site becomes a forum for the
   trade of unlicensed commercial software or worse. If anonymous FTP uploads
   are required, then verify the permissions so that these files cannot be
   read by other anonymous users until they have been reviewed by an
   administrator.

30.10. File and Print Services for Microsoft(R) Windows(R) Clients (Samba)

   Samba is a popular open source software package that provides file and
   print services using the SMB/CIFS protocol. This protocol is built into
   Microsoft(R) Windows(R) systems. It can be added to
   non-Microsoft(R) Windows(R) systems by installing the Samba client
   libraries. The protocol allows clients to access shared data and printers.
   These shares can be mapped as a local disk drive and shared printers can
   be used as if they were local printers.

   On FreeBSD, the Samba client libraries can be installed using the
   net/samba413 port or package. The client provides the ability for a
   FreeBSD system to access SMB/CIFS shares in a Microsoft(R) Windows(R)
   network.

   A FreeBSD system can also be configured to act as a Samba server by
   installing the same net/samba413 port or package. This allows the
   administrator to create SMB/CIFS shares on the FreeBSD system which can be
   accessed by clients running Microsoft(R) Windows(R) or the Samba client
   libraries.

  30.10.1. Server Configuration

   Samba is configured in /usr/local/etc/smb4.conf. This file must be created
   before Samba can be used.

   A simple smb4.conf to share directories and printers with Windows(R)
   clients in a workgroup is shown here. For more complex setups involving
   LDAP or Active Directory, it is easier to use samba-tool(8) to create the
   initial smb4.conf.

 [global]
 workgroup = WORKGROUP
 server string = Samba Server Version %v
 netbios name = ExampleMachine
 wins support = Yes
 security = user
 passdb backend = tdbsam

 # Example: share /usr/src accessible only to 'developer' user
 [src]
 path = /usr/src
 valid users = developer
 writable  = yes
 browsable = yes
 read only = no
 guest ok = no
 public = no
 create mask = 0666
 directory mask = 0755

    30.10.1.1. Global Settings

   Settings that describe the network are added in /usr/local/etc/smb4.conf:

   workgroup

           The name of the workgroup to be served.

   netbios name

           The NetBIOS name by which a Samba server is known. By default, it
           is the same as the first component of the host's DNS name.

   server string

           The string that will be displayed in the output of net view and
           some other networking tools that seek to display descriptive text
           about the server.

   wins support

           Whether Samba will act as a WINS server. Do not enable support for
           WINS on more than one server on the network.

    30.10.1.2. Security Settings

   The most important settings in /usr/local/etc/smb4.conf are the security
   model and the backend password format. These directives control the
   options:

   security

           The most common settings are security = share and security = user.
           If the clients use usernames that are the same as their usernames
           on the FreeBSD machine, user level security should be used. This
           is the default security policy and it requires clients to first
           log on before they can access shared resources.

           In share level security, clients do not need to log onto the
           server with a valid username and password before attempting to
           connect to a shared resource. This was the default security model
           for older versions of Samba.

   passdb backend

           Samba has several different backend authentication models. Clients
           may be authenticated with LDAP, NIS+, an SQL database, or a
           modified password file. The recommended authentication method,
           tdbsam, is ideal for simple networks and is covered here. For
           larger or more complex networks, ldapsam is recommended. smbpasswd
           was the former default and is now obsolete.

    30.10.1.3. Samba Users

   FreeBSD user accounts must be mapped to the SambaSAMAccount database for
   Windows(R) clients to access the share. Map existing FreeBSD user accounts
   using pdbedit(8):

 # pdbedit -a username

   This section has only mentioned the most commonly used settings. Refer to
   the Official Samba Wiki for additional information about the available
   configuration options.

  30.10.2. Starting Samba

   To enable Samba at boot time, add the following line to /etc/rc.conf:

 samba_server_enable="YES"

   To start Samba now:

 # service samba_server start
 Performing sanity check on Samba configuration: OK
 Starting nmbd.
 Starting smbd.

   Samba consists of three separate daemons. Both the nmbd and smbd daemons
   are started by samba_enable. If winbind name resolution is also required,
   set:

 winbindd_enable="YES"

   Samba can be stopped at any time by typing:

 # service samba_server stop

   Samba is a complex software suite with functionality that allows broad
   integration with Microsoft(R) Windows(R) networks. For more information
   about functionality beyond the basic configuration described here, refer
   to https://www.samba.org.

30.11. Clock Synchronization with NTP

   Over time, a computer's clock is prone to drift. This is problematic as
   many network services require the computers on a network to share the same
   accurate time. Accurate time is also needed to ensure that file timestamps
   stay consistent. The Network Time Protocol (NTP) is one way to provide
   clock accuracy in a network.

   FreeBSD includes ntpd(8) which can be configured to query other NTP
   servers to synchronize the clock on that machine or to provide time
   services to other computers in the network.

   This section describes how to configure ntpd on FreeBSD. Further
   documentation can be found in /usr/share/doc/ntp/ in HTML format.

  30.11.1. NTP Configuration

   On FreeBSD, the built-in ntpd can be used to synchronize a system's clock.
   Ntpd is configured using rc.conf(5) variables and /etc/ntp.conf, as
   detailed in the following sections.

   Ntpd communicates with its network peers using UDP packets. Any firewalls
   between your machine and its NTP peers must be configured to allow UDP
   packets in and out on port 123.

    30.11.1.1. The /etc/ntp.conf file

   Ntpd reads /etc/ntp.conf to determine which NTP servers to query. Choosing
   several NTP servers is recommended in case one of the servers becomes
   unreachable or its clock proves unreliable. As ntpd receives responses, it
   favors reliable servers over the less reliable ones. The servers which are
   queried can be local to the network, provided by an ISP, or selected from
   an online list of publicly accessible NTP servers. When choosing a public
   NTP server, select one that is geographically close and review its usage
   policy. The pool configuration keyword selects one or more servers from a
   pool of servers. An online list of publicly accessible NTP pools is
   available, organized by geographic area. In addition, FreeBSD provides a
   project-sponsored pool, 0.freebsd.pool.ntp.org.

   Example 30.3. Sample /etc/ntp.conf

   This is a simple example of an ntp.conf file. It can safely be used as-is;
   it contains the recommended restrict options for operation on a
   publicly-accessible network connection.

 # Disallow ntpq control/query access.  Allow peers to be added only
 # based on pool and server statements in this file.
 restrict default limited kod nomodify notrap noquery nopeer
 restrict source  limited kod nomodify notrap noquery

 # Allow unrestricted access from localhost for queries and control.
 restrict 127.0.0.1
 restrict ::1

 # Add a specific server.
 server ntplocal.example.com iburst

 # Add FreeBSD pool servers until 3-6 good servers are available.
 tos minclock 3 maxclock 6
 pool 0.freebsd.pool.ntp.org iburst

 # Use a local leap-seconds file.
 leapfile "/var/db/ntpd.leap-seconds.list"

   The format of this file is described in ntp.conf(5). The descriptions
   below provide a quick overview of just the keywords used in the sample
   file above.

   By default, an NTP server is accessible to any network host. The restrict
   keyword controls which systems can access the server. Multiple restrict
   entries are supported, each one refining the restrictions given in
   previous statements. The values shown in the example grant the local
   system full query and control access, while allowing remote systems only
   the ability to query the time. For more details, refer to the Access
   Control Support subsection of ntp.conf(5).

   The server keyword specifies a single server to query. The file can
   contain multiple server keywords, with one server listed on each line. The
   pool keyword specifies a pool of servers. Ntpd will add one or more
   servers from this pool as needed to reach the number of peers specified
   using the tos minclock value. The iburst keyword directs ntpd to perform a
   burst of eight quick packet exchanges with a server when contact is first
   established, to help quickly synchronize system time.

   The leapfile keyword specifies the location of a file containing
   information about leap seconds. The file is updated automatically by
   periodic(8). The file location specified by this keyword must match the
   location set in the ntp_db_leapfile variable in /etc/rc.conf.

    30.11.1.2. NTP entries in /etc/rc.conf

   Set ntpd_enable=YES to start ntpd at boot time. Once ntpd_enable=YES has
   been added to /etc/rc.conf, ntpd can be started immediately without
   rebooting the system by typing:

 # service ntpd start

   Only ntpd_enable must be set to use ntpd. The rc.conf variables listed
   below may also be set as needed.

   Set ntpd_sync_on_start=YES to allow ntpd to step the clock any amount, one
   time at startup. Normally ntpd will log an error message and exit if the
   clock is off by more than 1000 seconds. This option is especially useful
   on systems without a battery-backed realtime clock.

   Set ntpd_oomprotect=YES to protect the ntpd daemon from being killed by
   the system attempting to recover from an Out Of Memory (OOM) condition.

   Set ntpd_config= to the location of an alternate ntp.conf file.

   Set ntpd_flags= to contain any other ntpd flags as needed, but avoid using
   these flags which are managed internally by /etc/rc.d/ntpd:

     * -p (pid file location)

     * -c (set ntpd_config= instead)

    30.11.1.3. Ntpd and the unpriveleged ntpd user

   Ntpd on FreeBSD can start and run as an unpriveleged user. Doing so
   requires the mac_ntpd(4) policy module. The /etc/rc.d/ntpd startup script
   first examines the NTP configuration. If possible, it loads the mac_ntpd
   module, then starts ntpd as unpriveleged user ntpd (user id 123). To avoid
   problems with file and directory access, the startup script will not
   automatically start ntpd as ntpd when the configuration contains any
   file-related options.

   The presence of any of the following in ntpd_flags requires manual
   configuration as described below to run as the ntpd user:

     * -f or --driftfile

     * -i or --jaildir

     * -k or --keyfile

     * -l or --logfile

     * -s or --statsdir

   The presence of any of the following keywords in ntp.conf requires manual
   configuration as described below to run as the ntpd user:

     * crypto

     * driftfile

     * key

     * logdir

     * statsdir

   To manually configure ntpd to run as user ntpd you must:

     * Ensure that the ntpd user has access to all the files and directories
       specified in the configuration.

     * Arrange for the mac_ntpd module to be loaded or compiled into the
       kernel. See mac_ntpd(4) for details.

     * Set ntpd_user="ntpd" in /etc/rc.conf

  30.11.2. Using NTP with a PPP Connection

   ntpd does not need a permanent connection to the Internet to function
   properly. However, if a PPP connection is configured to dial out on
   demand, NTP traffic should be prevented from triggering a dial out or
   keeping the connection alive. This can be configured with filter
   directives in /etc/ppp/ppp.conf. For example:

 set filter dial 0 deny udp src eq 123
 # Prevent NTP traffic from initiating dial out
 set filter dial 1 permit 0 0
 set filter alive 0 deny udp src eq 123
 # Prevent incoming NTP traffic from keeping the connection open
 set filter alive 1 deny udp dst eq 123
 # Prevent outgoing NTP traffic from keeping the connection open
 set filter alive 2 permit 0/0 0/0

   For more details, refer to the PACKET FILTERING section in ppp(8) and the
   examples in /usr/share/examples/ppp/.

  Note:

   Some Internet access providers block low-numbered ports, preventing NTP
   from functioning since replies never reach the machine.

30.12. iSCSI Initiator and Target Configuration

   iSCSI is a way to share storage over a network. Unlike NFS, which works at
   the file system level, iSCSI works at the block device level.

   In iSCSI terminology, the system that shares the storage is known as the
   target. The storage can be a physical disk, or an area representing
   multiple disks or a portion of a physical disk. For example, if the
   disk(s) are formatted with ZFS, a zvol can be created to use as the iSCSI
   storage.

   The clients which access the iSCSI storage are called initiators. To
   initiators, the storage available through iSCSI appears as a raw,
   unformatted disk known as a LUN. Device nodes for the disk appear in /dev/
   and the device must be separately formatted and mounted.

   FreeBSD provides a native, kernel-based iSCSI target and initiator. This
   section describes how to configure a FreeBSD system as a target or an
   initiator.

  30.12.1. Configuring an iSCSI Target

   To configure an iSCSI target, create the /etc/ctl.conf configuration file,
   add a line to /etc/rc.conf to make sure the ctld(8) daemon is
   automatically started at boot, and then start the daemon.

   The following is an example of a simple /etc/ctl.conf configuration file.
   Refer to ctl.conf(5) for a more complete description of this file's
   available options.

 portal-group pg0 {
         discovery-auth-group no-authentication
         listen 0.0.0.0
         listen [::]
 }

 target iqn.2012-06.com.example:target0 {
         auth-group no-authentication
         portal-group pg0

         lun 0 {
                 path /data/target0-0
                 size 4G
         }
 }

   The first entry defines the pg0 portal group. Portal groups define which
   network addresses the ctld(8) daemon will listen on. The
   discovery-auth-group no-authentication entry indicates that any initiator
   is allowed to perform iSCSI target discovery without authentication. Lines
   three and four configure ctld(8) to listen on all IPv4 (listen 0.0.0.0)
   and IPv6 (listen [::]) addresses on the default port of 3260.

   It is not necessary to define a portal group as there is a built-in portal
   group called default. In this case, the difference between default and pg0
   is that with default, target discovery is always denied, while with pg0,
   it is always allowed.

   The second entry defines a single target. Target has two possible
   meanings: a machine serving iSCSI or a named group of LUNs. This example
   uses the latter meaning, where iqn.2012-06.com.example:target0 is the
   target name. This target name is suitable for testing purposes. For actual
   use, change com.example to the real domain name, reversed. The 2012-06
   represents the year and month of acquiring control of that domain name,
   and target0 can be any value. Any number of targets can be defined in this
   configuration file.

   The auth-group no-authentication line allows all initiators to connect to
   the specified target and portal-group pg0 makes the target reachable
   through the pg0 portal group.

   The next section defines the LUN. To the initiator, each LUN will be
   visible as a separate disk device. Multiple LUNs can be defined for each
   target. Each LUN is identified by a number, where LUN 0 is mandatory. The
   path /data/target0-0 line defines the full path to a file or zvol backing
   the LUN. That path must exist before starting ctld(8). The second line is
   optional and specifies the size of the LUN.

   Next, to make sure the ctld(8) daemon is started at boot, add this line to
   /etc/rc.conf:

 ctld_enable="YES"

   To start ctld(8) now, run this command:

 # service ctld start

   As the ctld(8) daemon is started, it reads /etc/ctl.conf. If this file is
   edited after the daemon starts, use this command so that the changes take
   effect immediately:

 # service ctld reload

    30.12.1.1. Authentication

   The previous example is inherently insecure as it uses no authentication,
   granting anyone full access to all targets. To require a username and
   password to access targets, modify the configuration as follows:

 auth-group ag0 {
         chap username1 secretsecret
         chap username2 anothersecret
 }

 portal-group pg0 {
         discovery-auth-group no-authentication
         listen 0.0.0.0
         listen [::]
 }

 target iqn.2012-06.com.example:target0 {
         auth-group ag0
         portal-group pg0
         lun 0 {
                 path /data/target0-0
                 size 4G
         }
 }

   The auth-group section defines username and password pairs. An initiator
   trying to connect to iqn.2012-06.com.example:target0 must first specify a
   defined username and secret. However, target discovery is still permitted
   without authentication. To require target discovery authentication, set
   discovery-auth-group to a defined auth-group name instead of
   no-authentication.

   It is common to define a single exported target for every initiator. As a
   shorthand for the syntax above, the username and password can be specified
   directly in the target entry:

 target iqn.2012-06.com.example:target0 {
         portal-group pg0
         chap username1 secretsecret

         lun 0 {
                 path /data/target0-0
                 size 4G
         }
 }

  30.12.2. Configuring an iSCSI Initiator

  Note:

   The iSCSI initiator described in this section is supported starting with
   FreeBSD 10.0-RELEASE. To use the iSCSI initiator available in older
   versions, refer to iscontrol(8).

   The iSCSI initiator requires that the iscsid(8) daemon is running. This
   daemon does not use a configuration file. To start it automatically at
   boot, add this line to /etc/rc.conf:

 iscsid_enable="YES"

   To start iscsid(8) now, run this command:

 # service iscsid start

   Connecting to a target can be done with or without an /etc/iscsi.conf
   configuration file. This section demonstrates both types of connections.

    30.12.2.1. Connecting to a Target Without a Configuration File

   To connect an initiator to a single target, specify the IP address of the
   portal and the name of the target:

 # iscsictl -A -p 10.10.10.10 -t iqn.2012-06.com.example:target0

   To verify if the connection succeeded, run iscsictl without any arguments.
   The output should look similar to this:

 Target name                                     Target portal   State
 iqn.2012-06.com.example:target0                 10.10.10.10     Connected: da0

   In this example, the iSCSI session was successfully established, with
   /dev/da0 representing the attached LUN. If the
   iqn.2012-06.com.example:target0 target exports more than one LUN, multiple
   device nodes will be shown in that section of the output:

 Connected: da0 da1 da2.

   Any errors will be reported in the output, as well as the system logs. For
   example, this message usually means that the iscsid(8) daemon is not
   running:

 Target name                                     Target portal   State
 iqn.2012-06.com.example:target0                 10.10.10.10     Waiting for iscsid(8)

   The following message suggests a networking problem, such as a wrong IP
   address or port:

 Target name                                     Target portal   State
 iqn.2012-06.com.example:target0                 10.10.10.11     Connection refused

   This message means that the specified target name is wrong:

 Target name                                     Target portal   State
 iqn.2012-06.com.example:target0                 10.10.10.10     Not found

   This message means that the target requires authentication:

 Target name                                     Target portal   State
 iqn.2012-06.com.example:target0                 10.10.10.10     Authentication failed

   To specify a CHAP username and secret, use this syntax:

 # iscsictl -A -p 10.10.10.10 -t iqn.2012-06.com.example:target0 -u user -s secretsecret

    30.12.2.2. Connecting to a Target with a Configuration File

   To connect using a configuration file, create /etc/iscsi.conf with
   contents like this:

 t0 {
         TargetAddress   = 10.10.10.10
         TargetName      = iqn.2012-06.com.example:target0
         AuthMethod      = CHAP
         chapIName       = user
         chapSecret      = secretsecret
 }

   The t0 specifies a nickname for the configuration file section. It will be
   used by the initiator to specify which configuration to use. The other
   lines specify the parameters to use during connection. The TargetAddress
   and TargetName are mandatory, whereas the other options are optional. In
   this example, the CHAP username and secret are shown.

   To connect to the defined target, specify the nickname:

 # iscsictl -An t0

   Alternately, to connect to all targets defined in the configuration file,
   use:

 # iscsictl -Aa

   To make the initiator automatically connect to all targets in
   /etc/iscsi.conf, add the following to /etc/rc.conf:

 iscsictl_enable="YES"
 iscsictl_flags="-Aa"

Chapter 31. Firewalls

   Contributed by Joseph J. Barbish.
   Converted to SGML and updated by Brad Davis.
   Table of Contents

   31.1. Synopsis

   31.2. Firewall Concepts

   31.3. PF

   31.4. IPFW

   31.5. IPFILTER (IPF)

   31.6. Blacklistd

31.1. Synopsis

   Firewalls make it possible to filter the incoming and outgoing traffic
   that flows through a system. A firewall can use one or more sets of
   "rules" to inspect network packets as they come in or go out of network
   connections and either allows the traffic through or blocks it. The rules
   of a firewall can inspect one or more characteristics of the packets such
   as the protocol type, source or destination host address, and source or
   destination port.

   Firewalls can enhance the security of a host or a network. They can be
   used to do one or more of the following:

     * Protect and insulate the applications, services, and machines of an
       internal network from unwanted traffic from the public Internet.

     * Limit or disable access from hosts of the internal network to services
       of the public Internet.

     * Support network address translation (NAT), which allows an internal
       network to use private IP addresses and share a single connection to
       the public Internet using either a single IP address or a shared pool
       of automatically assigned public addresses.

   FreeBSD has three firewalls built into the base system: PF, IPFW, and
   IPFILTER, also known as IPF. FreeBSD also provides two traffic shapers for
   controlling bandwidth usage: altq(4) and dummynet(4). ALTQ has
   traditionally been closely tied with PF and dummynet with IPFW. Each
   firewall uses rules to control the access of packets to and from a FreeBSD
   system, although they go about it in different ways and each has a
   different rule syntax.

   FreeBSD provides multiple firewalls in order to meet the different
   requirements and preferences for a wide variety of users. Each user should
   evaluate which firewall best meets their needs.

   After reading this chapter, you will know:

     * How to define packet filtering rules.

     * The differences between the firewalls built into FreeBSD.

     * How to use and configure the PF firewall.

     * How to use and configure the IPFW firewall.

     * How to use and configure the IPFILTER firewall.

   Before reading this chapter, you should:

     * Understand basic FreeBSD and Internet concepts.

  Note:

   Since all firewalls are based on inspecting the values of selected packet
   control fields, the creator of the firewall ruleset must have an
   understanding of how TCP/IP works, what the different values in the packet
   control fields are, and how these values are used in a normal session
   conversation. For a good introduction, refer to Daryl's TCP/IP Primer.

31.2. Firewall Concepts

   A ruleset contains a group of rules which pass or block packets based on
   the values contained in the packet. The bi-directional exchange of packets
   between hosts comprises a session conversation. The firewall ruleset
   processes both the packets arriving from the public Internet, as well as
   the packets produced by the system as a response to them. Each TCP/IP
   service is predefined by its protocol and listening port. Packets destined
   for a specific service originate from the source address using an
   unprivileged port and target the specific service port on the destination
   address. All the above parameters can be used as selection criteria to
   create rules which will pass or block services.

   To lookup unknown port numbers, refer to /etc/services. Alternatively,
   visit http://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers and do
   a port number lookup to find the purpose of a particular port number.

   Check out this link for port numbers used by Trojans.

   FTP has two modes: active mode and passive mode. The difference is in how
   the data channel is acquired. Passive mode is more secure as the data
   channel is acquired by the ordinal ftp session requester. For a good
   explanation of FTP and the different modes, see
   http://www.slacksite.com/other/ftp.html.

   A firewall ruleset can be either "exclusive" or "inclusive". An exclusive
   firewall allows all traffic through except for the traffic matching the
   ruleset. An inclusive firewall does the reverse as it only allows traffic
   matching the rules through and blocks everything else.

   An inclusive firewall offers better control of the outgoing traffic,
   making it a better choice for systems that offer services to the public
   Internet. It also controls the type of traffic originating from the public
   Internet that can gain access to a private network. All traffic that does
   not match the rules is blocked and logged. Inclusive firewalls are
   generally safer than exclusive firewalls because they significantly reduce
   the risk of allowing unwanted traffic.

  Note:

   Unless noted otherwise, all configuration and example rulesets in this
   chapter create inclusive firewall rulesets.

   Security can be tightened further using a "stateful firewall". This type
   of firewall keeps track of open connections and only allows traffic which
   either matches an existing connection or opens a new, allowed connection.

   Stateful filtering treats traffic as a bi-directional exchange of packets
   comprising a session. When state is specified on a matching rule the
   firewall dynamically generates internal rules for each anticipated packet
   being exchanged during the session. It has sufficient matching
   capabilities to determine if a packet is valid for a session. Any packets
   that do not properly fit the session template are automatically rejected.

   When the session completes, it is removed from the dynamic state table.

   Stateful filtering allows one to focus on blocking/passing new sessions.
   If the new session is passed, all its subsequent packets are allowed
   automatically and any impostor packets are automatically rejected. If a
   new session is blocked, none of its subsequent packets are allowed.
   Stateful filtering provides advanced matching abilities capable of
   defending against the flood of different attack methods employed by
   attackers.

   NAT stands for Network Address Translation. NAT function enables the
   private LAN behind the firewall to share a single ISP-assigned IP address,
   even if that address is dynamically assigned. NAT allows each computer in
   the LAN to have Internet access, without having to pay the ISP for
   multiple Internet accounts or IP addresses.

   NAT will automatically translate the private LAN IP address for each
   system on the LAN to the single public IP address as packets exit the
   firewall bound for the public Internet. It also performs the reverse
   translation for returning packets.

   According to RFC 1918, the following IP address ranges are reserved for
   private networks which will never be routed directly to the public
   Internet, and therefore are available for use with NAT:

     * 10.0.0.0/8.

     * 172.16.0.0/12.

     * 192.168.0.0/16.

  Warning:

   When working with the firewall rules, be very careful. Some configurations
   can lock the administrator out of the server. To be on the safe side,
   consider performing the initial firewall configuration from the local
   console rather than doing it remotely over ssh.

31.3. PF

   Revised and updated by John Ferrell.

   Since FreeBSD 5.3, a ported version of OpenBSD's PF firewall has been
   included as an integrated part of the base system. PF is a complete,
   full-featured firewall that has optional support for ALTQ (Alternate
   Queuing), which provides Quality of Service (QoS).

   The OpenBSD Project maintains the definitive reference for PF in the PF
   FAQ. Peter Hansteen maintains a thorough PF tutorial at
   http://home.nuug.no/~peter/pf/.

  Warning:

   When reading the PF FAQ, keep in mind that FreeBSD's version of PF has
   diverged substantially from the upstream OpenBSD version over the years.
   Not all features work the same way on FreeBSD as they do in OpenBSD and
   vice versa.

   The FreeBSD packet filter mailing list is a good place to ask questions
   about configuring and running the PF firewall. Check the mailing list
   archives before asking a question as it may have already been answered.

   This section of the Handbook focuses on PF as it pertains to FreeBSD. It
   demonstrates how to enable PF and ALTQ. It also provides several examples
   for creating rulesets on a FreeBSD system.

  31.3.1. Enabling PF

   To use PF, its kernel module must be first loaded. This section describes
   the entries that can be added to /etc/rc.conf to enable PF.

   Start by adding pf_enable=yes to /etc/rc.conf:

 # sysrc pf_enable=yes

   Additional options, described in pfctl(8), can be passed to PF when it is
   started. Add or change this entry in /etc/rc.conf and specify any required
   flags between the two quotes (""):

 pf_flags=""                     # additional flags for pfctl startup

   PF will not start if it cannot find its ruleset configuration file. By
   default, FreeBSD does not ship with a ruleset and there is no
   /etc/pf.conf. Example rulesets can be found in /usr/share/examples/pf/. If
   a custom ruleset has been saved somewhere else, add a line to /etc/rc.conf
   which specifies the full path to the file:

 pf_rules="/path/to/pf.conf"

   Logging support for PF is provided by pflog(4). To enable logging support,
   add pflog_enable=yes to /etc/rc.conf:

 # sysrc pflog_enable=yes

   The following lines can also be added to change the default location of
   the log file or to specify any additional flags to pass to pflog(4) when
   it is started:

 pflog_logfile="/var/log/pflog"  # where pflogd should store the logfile
 pflog_flags=""                  # additional flags for pflogd startup

   Finally, if there is a LAN behind the firewall and packets need to be
   forwarded for the computers on the LAN, or NAT is required, enable the
   following option:

 gateway_enable="YES"            # Enable as LAN gateway

   After saving the needed edits, PF can be started with logging support by
   typing:

 # service pf start
 # service pflog start

   By default, PF reads its configuration rules from /etc/pf.conf and
   modifies, drops, or passes packets according to the rules or definitions
   specified in this file. The FreeBSD installation includes several sample
   files located in /usr/share/examples/pf/. Refer to the PF FAQ for complete
   coverage of PF rulesets.

   To control PF, use pfctl. Table 31.1, "Useful pfctl Options" summarizes
   some useful options to this command. Refer to pfctl(8) for a description
   of all available options:

   Table 31.1. Useful pfctl Options

             Command                               Purpose                    
   pfctl -e                     Enable PF.                                    
   pfctl -d                     Disable PF.                                   
   pfctl -F all -f /etc/pf.conf Flush all NAT, filter, state, and table rules 
                                and reload /etc/pf.conf.                      
   pfctl -s [ rules | nat |     Report on the filter rules, NAT rules, or     
   states ]                     state table.                                  
   pfctl -vnf /etc/pf.conf      Check /etc/pf.conf for errors, but do not     
                                load ruleset.                                 

  Tip:

   security/sudo is useful for running commands like pfctl that require
   elevated privileges. It can be installed from the Ports Collection.

   To keep an eye on the traffic that passes through the PF firewall,
   consider installing the sysutils/pftop package or port. Once installed,
   pftop can be run to view a running snapshot of traffic in a format which
   is similar to top(1).

  31.3.2. PF Rulesets

   Contributed by Peter N. M. Hansteen.

   This section demonstrates how to create a customized ruleset. It starts
   with the simplest of rulesets and builds upon its concepts using several
   examples to demonstrate real-world usage of PF's many features.

   The simplest possible ruleset is for a single machine that does not run
   any services and which needs access to one network, which may be the
   Internet. To create this minimal ruleset, edit /etc/pf.conf so it looks
   like this:

 block in all
 pass out all keep state

   The first rule denies all incoming traffic by default. The second rule
   allows connections created by this system to pass out, while retaining
   state information on those connections. This state information allows
   return traffic for those connections to pass back and should only be used
   on machines that can be trusted. The ruleset can be loaded with:

 # pfctl -e ; pfctl -f /etc/pf.conf

   In addition to keeping state, PF provides lists and macros which can be
   defined for use when creating rules. Macros can include lists and need to
   be defined before use. As an example, insert these lines at the very top
   of the ruleset:

 tcp_services = "{ ssh, smtp, domain, www, pop3, auth, pop3s }"
 udp_services = "{ domain }"

   PF understands port names as well as port numbers, as long as the names
   are listed in /etc/services. This example creates two macros. The first is
   a list of seven TCP port names and the second is one UDP port name. Once
   defined, macros can be used in rules. In this example, all traffic is
   blocked except for the connections initiated by this system for the seven
   specified TCP services and the one specified UDP service:

 tcp_services = "{ ssh, smtp, domain, www, pop3, auth, pop3s }"
 udp_services = "{ domain }"
 block all
 pass out proto tcp to any port $tcp_services keep state
 pass proto udp to any port $udp_services keep state

   Even though UDP is considered to be a stateless protocol, PF is able to
   track some state information. For example, when a UDP request is passed
   which asks a name server about a domain name, PF will watch for the
   response to pass it back.

   Whenever an edit is made to a ruleset, the new rules must be loaded so
   they can be used:

 # pfctl -f /etc/pf.conf

   If there are no syntax errors, pfctl will not output any messages during
   the rule load. Rules can also be tested before attempting to load them:

 # pfctl -nf /etc/pf.conf

   Including -n causes the rules to be interpreted only, but not loaded. This
   provides an opportunity to correct any errors. At all times, the last
   valid ruleset loaded will be enforced until either PF is disabled or a new
   ruleset is loaded.

  Tip:

   Adding -v to a pfctl ruleset verify or load will display the fully parsed
   rules exactly the way they will be loaded. This is extremely useful when
   debugging rules.

    31.3.2.1. A Simple Gateway with NAT

   This section demonstrates how to configure a FreeBSD system running PF to
   act as a gateway for at least one other machine. The gateway needs at
   least two network interfaces, each connected to a separate network. In
   this example, xl0 is connected to the Internet and xl1 is connected to the
   internal network.

   First, enable the gateway to let the machine forward the network traffic
   it receives on one interface to another interface. This sysctl setting
   will forward IPv4 packets:

 # sysctl net.inet.ip.forwarding=1

   To forward IPv6 traffic, use:

 # sysctl net.inet6.ip6.forwarding=1

   To enable these settings at system boot, use sysrc(8) to add them to
   /etc/rc.conf:

 # sysrc gateway_enable=yes
 # sysrc ipv6_gateway_enable=yes

   Verify with ifconfig that both of the interfaces are up and running.

   Next, create the PF rules to allow the gateway to pass traffic. While the
   following rule allows stateful traffic from hosts of the internal network
   to pass to the gateway, the to keyword does not guarantee passage all the
   way from source to destination:

 pass in on xl1 from xl1:network to xl0:network port $ports keep state

   That rule only lets the traffic pass in to the gateway on the internal
   interface. To let the packets go further, a matching rule is needed:

 pass out on xl0 from xl1:network to xl0:network port $ports keep state

   While these two rules will work, rules this specific are rarely needed.
   For a busy network admin, a readable ruleset is a safer ruleset. The
   remainder of this section demonstrates how to keep the rules as simple as
   possible for readability. For example, those two rules could be replaced
   with one rule:

 pass from xl1:network to any port $ports keep state

   The interface:network notation can be replaced with a macro to make the
   ruleset even more readable. For example, a $localnet macro could be
   defined as the network directly attached to the internal interface
   ($xl1:network). Alternatively, the definition of $localnet could be
   changed to an IP address/netmask notation to denote a network, such as
   192.168.100.1/24 for a subnet of private addresses.

   If required, $localnet could even be defined as a list of networks.
   Whatever the specific needs, a sensible $localnet definition could be used
   in a typical pass rule as follows:

 pass from $localnet to any port $ports keep state

   The following sample ruleset allows all traffic initiated by machines on
   the internal network. It first defines two macros to represent the
   external and internal 3COM interfaces of the gateway.

  Note:

   For dialup users, the external interface will use tun0. For an ADSL
   connection, specifically those using PPP over Ethernet (PPPoE), the
   correct external interface is tun0, not the physical Ethernet interface.

 ext_if = "xl0"  # macro for external interface - use tun0 for PPPoE
 int_if = "xl1"  # macro for internal interface
 localnet = $int_if:network
 # ext_if IP address could be dynamic, hence ($ext_if)
 nat on $ext_if from $localnet to any -> ($ext_if)
 block all
 pass from { lo0, $localnet } to any keep state

   This ruleset introduces the nat rule which is used to handle the network
   address translation from the non-routable addresses inside the internal
   network to the IP address assigned to the external interface. The
   parentheses surrounding the last part of the nat rule ($ext_if) is
   included when the IP address of the external interface is dynamically
   assigned. It ensures that network traffic runs without serious
   interruptions even if the external IP address changes.

   Note that this ruleset probably allows more traffic to pass out of the
   network than is needed. One reasonable setup could create this macro:

 client_out = "{ ftp-data, ftp, ssh, domain, pop3, auth, nntp, http, \
     https, cvspserver, 2628, 5999, 8000, 8080 }"

   to use in the main pass rule:

 pass inet proto tcp from $localnet to any port $client_out \
     flags S/SA keep state

   A few other pass rules may be needed. This one enables SSH on the external
   interface:

 pass in inet proto tcp to $ext_if port ssh

   This macro definition and rule allows DNS and NTP for internal clients:

 udp_services = "{ domain, ntp }"
 pass quick inet proto { tcp, udp } to any port $udp_services keep state

   Note the quick keyword in this rule. Since the ruleset consists of several
   rules, it is important to understand the relationships between the rules
   in a ruleset. Rules are evaluated from top to bottom, in the sequence they
   are written. For each packet or connection evaluated by PF, the last
   matching rule in the ruleset is the one which is applied. However, when a
   packet matches a rule which contains the quick keyword, the rule
   processing stops and the packet is treated according to that rule. This is
   very useful when an exception to the general rules is needed.

    31.3.2.2. Creating an FTP Proxy

   Configuring working FTP rules can be problematic due to the nature of the
   FTP protocol. FTP pre-dates firewalls by several decades and is insecure
   in its design. The most common points against using FTP include:

     * Passwords are transferred in the clear.

     * The protocol demands the use of at least two TCP connections (control
       and data) on separate ports.

     * When a session is established, data is communicated using randomly
       selected ports.

   All of these points present security challenges, even before considering
   any potential security weaknesses in client or server software. More
   secure alternatives for file transfer exist, such as sftp(1) or scp(1),
   which both feature authentication and data transfer over encrypted
   connections..

   For those situations when FTP is required, PF provides redirection of FTP
   traffic to a small proxy program called ftp-proxy(8), which is included in
   the base system of FreeBSD. The role of the proxy is to dynamically insert
   and delete rules in the ruleset, using a set of anchors, to correctly
   handle FTP traffic.

   To enable the FTP proxy, add this line to /etc/rc.conf:

 ftpproxy_enable="YES"

   Then start the proxy by running service ftp-proxy start.

   For a basic configuration, three elements need to be added to
   /etc/pf.conf. First, the anchors which the proxy will use to insert the
   rules it generates for the FTP sessions:

 nat-anchor "ftp-proxy/*"
 rdr-anchor "ftp-proxy/*"

   Second, a pass rule is needed to allow FTP traffic in to the proxy.

   Third, redirection and NAT rules need to be defined before the filtering
   rules. Insert this rdr rule immediately after the nat rule:

 rdr pass on $int_if proto tcp from any to any port ftp -> 127.0.0.1 port 8021

   Finally, allow the redirected traffic to pass:

 pass out proto tcp from $proxy to any port ftp

   where $proxy expands to the address the proxy daemon is bound to.

   Save /etc/pf.conf, load the new rules, and verify from a client that FTP
   connections are working:

 # pfctl -f /etc/pf.conf

   This example covers a basic setup where the clients in the local network
   need to contact FTP servers elsewhere. This basic configuration should
   work well with most combinations of FTP clients and servers. As shown in
   ftp-proxy(8), the proxy's behavior can be changed in various ways by
   adding options to the ftpproxy_flags= line. Some clients or servers may
   have specific quirks that must be compensated for in the configuration, or
   there may be a need to integrate the proxy in specific ways such as
   assigning FTP traffic to a specific queue.

   For ways to run an FTP server protected by PF and ftp-proxy(8), configure
   a separate ftp-proxy in reverse mode, using -R, on a separate port with
   its own redirecting pass rule.

    31.3.2.3. Managing ICMP

   Many of the tools used for debugging or troubleshooting a TCP/IP network
   rely on the Internet Control Message Protocol (ICMP), which was designed
   specifically with debugging in mind.

   The ICMP protocol sends and receives control messages between hosts and
   gateways, mainly to provide feedback to a sender about any unusual or
   difficult conditions enroute to the target host. Routers use ICMP to
   negotiate packet sizes and other transmission parameters in a process
   often referred to as path MTU discovery.

   From a firewall perspective, some ICMP control messages are vulnerable to
   known attack vectors. Also, letting all diagnostic traffic pass
   unconditionally makes debugging easier, but it also makes it easier for
   others to extract information about the network. For these reasons, the
   following rule may not be optimal:

 pass inet proto icmp from any to any

   One solution is to let all ICMP traffic from the local network through
   while stopping all probes from outside the network:

 pass inet proto icmp from $localnet to any keep state
 pass inet proto icmp from any to $ext_if keep state

   Additional options are available which demonstrate some of PF's
   flexibility. For example, rather than allowing all ICMP messages, one can
   specify the messages used by ping(8) and traceroute(8). Start by defining
   a macro for that type of message:

 icmp_types = "echoreq"

   and a rule which uses the macro:

 pass inet proto icmp all icmp-type $icmp_types keep state

   If other types of ICMP packets are needed, expand icmp_types to a list of
   those packet types. Type more /usr/src/sbin/pfctl/pfctl_parser.c to see
   the list of ICMP message types supported by PF. Refer to
   http://www.iana.org/assignments/icmp-parameters/icmp-parameters.xhtml for
   an explanation of each message type.

   Since Unix traceroute uses UDP by default, another rule is needed to allow
   Unix traceroute:

 # allow out the default range for traceroute(8):
 pass out on $ext_if inet proto udp from any to any port 33433 >< 33626 keep state

   Since TRACERT.EXE on Microsoft Windows systems uses ICMP echo request
   messages, only the first rule is needed to allow network traces from those
   systems. Unix traceroute can be instructed to use other protocols as well,
   and will use ICMP echo request messages if -I is used. Check the
   traceroute(8) man page for details.

      31.3.2.3.1. Path MTU Discovery

   Internet protocols are designed to be device independent, and one
   consequence of device independence is that the optimal packet size for a
   given connection cannot always be predicted reliably. The main constraint
   on packet size is the Maximum Transmission Unit (MTU) which sets the upper
   limit on the packet size for an interface. Type ifconfig to view the MTUs
   for a system's network interfaces.

   TCP/IP uses a process known as path MTU discovery to determine the right
   packet size for a connection. This process sends packets of varying sizes
   with the "Do not fragment" flag set, expecting an ICMP return packet of
   "type 3, code 4" when the upper limit has been reached. Type 3 means
   "destination unreachable", and code 4 is short for "fragmentation needed,
   but the do-not-fragment flag is set". To allow path MTU discovery in order
   to support connections to other MTUs, add the destination unreachable type
   to the icmp_types macro:

 icmp_types = "{ echoreq, unreach }"

   Since the pass rule already uses that macro, it does not need to be
   modified to support the new ICMP type:

 pass inet proto icmp all icmp-type $icmp_types keep state

   PF allows filtering on all variations of ICMP types and codes. The list of
   possible types and codes are documented in icmp(4) and icmp6(4).

    31.3.2.4. Using Tables

   Some types of data are relevant to filtering and redirection at a given
   time, but their definition is too long to be included in the ruleset file.
   PF supports the use of tables, which are defined lists that can be
   manipulated without needing to reload the entire ruleset, and which can
   provide fast lookups. Table names are always enclosed within < >, like
   this:

 table <clients> { 192.168.2.0/24, !192.168.2.5 }

   In this example, the 192.168.2.0/24 network is part of the table, except
   for the address 192.168.2.5, which is excluded using the ! operator. It is
   also possible to load tables from files where each item is on a separate
   line, as seen in this example /etc/clients:

 192.168.2.0/24
 !192.168.2.5

   To refer to the file, define the table like this:

 table <clients> persist file "/etc/clients"

   Once the table is defined, it can be referenced by a rule:

 pass inet proto tcp from <clients> to any port $client_out flags S/SA keep state

   A table's contents can be manipulated live, using pfctl. This example adds
   another network to the table:

 # pfctl -t clients -T add 192.168.1.0/16

   Note that any changes made this way will take affect now, making them
   ideal for testing, but will not survive a power failure or reboot. To make
   the changes permanent, modify the definition of the table in the ruleset
   or edit the file that the table refers to. One can maintain the on-disk
   copy of the table using a cron(8) job which dumps the table's contents to
   disk at regular intervals, using a command such as pfctl -t clients -T
   show >/etc/clients. Alternatively, /etc/clients can be updated with the
   in-memory table contents:

 # pfctl -t clients -T replace -f /etc/clients

    31.3.2.5. Using Overload Tables to Protect SSH

   Those who run SSH on an external interface have probably seen something
   like this in the authentication logs:

 Sep 26 03:12:34 skapet sshd[25771]: Failed password for root from 200.72.41.31 port 40992 ssh2
 Sep 26 03:12:34 skapet sshd[5279]: Failed password for root from 200.72.41.31 port 40992 ssh2
 Sep 26 03:12:35 skapet sshd[5279]: Received disconnect from 200.72.41.31: 11: Bye Bye
 Sep 26 03:12:44 skapet sshd[29635]: Invalid user admin from 200.72.41.31
 Sep 26 03:12:44 skapet sshd[24703]: input_userauth_request: invalid user admin
 Sep 26 03:12:44 skapet sshd[24703]: Failed password for invalid user admin from 200.72.41.31 port 41484 ssh2

   This is indicative of a brute force attack where somebody or some program
   is trying to discover the user name and password which will let them into
   the system.

   If external SSH access is needed for legitimate users, changing the
   default port used by SSH can offer some protection. However, PF provides a
   more elegant solution. Pass rules can contain limits on what connecting
   hosts can do and violators can be banished to a table of addresses which
   are denied some or all access. It is even possible to drop all existing
   connections from machines which overreach the limits.

   To configure this, create this table in the tables section of the ruleset:

 table <bruteforce> persist

   Then, somewhere early in the ruleset, add rules to block brute access
   while allowing legitimate access:

 block quick from <bruteforce>
 pass inet proto tcp from any to $localnet port $tcp_services \
     flags S/SA keep state \
     (max-src-conn 100, max-src-conn-rate 15/5, \
     overload <bruteforce> flush global)

   The part in parentheses defines the limits and the numbers should be
   changed to meet local requirements. It can be read as follows:

   max-src-conn is the number of simultaneous connections allowed from one
   host.

   max-src-conn-rate is the rate of new connections allowed from any single
   host (15) per number of seconds (5).

   overload <bruteforce> means that any host which exceeds these limits gets
   its address added to the bruteforce table. The ruleset blocks all traffic
   from addresses in the bruteforce table.

   Finally, flush global says that when a host reaches the limit, that all
   (global) of that host's connections will be terminated (flush).

  Note:

   These rules will not block slow bruteforcers, as described in
   http://home.nuug.no/~peter/hailmary2013/.

   This example ruleset is intended mainly as an illustration. For example,
   if a generous number of connections in general are wanted, but the desire
   is to be more restrictive when it comes to ssh, supplement the rule above
   with something like the one below, early on in the rule set:

 pass quick proto { tcp, udp } from any to any port ssh \
     flags S/SA keep state \
     (max-src-conn 15, max-src-conn-rate 5/3, \
     overload <bruteforce> flush global)

  It May Not be Necessary to Block All Overloaders:

   It is worth noting that the overload mechanism is a general technique
   which does not apply exclusively to SSH, and it is not always optimal to
   entirely block all traffic from offenders.

   For example, an overload rule could be used to protect a mail service or a
   web service, and the overload table could be used in a rule to assign
   offenders to a queue with a minimal bandwidth allocation or to redirect to
   a specific web page.

   Over time, tables will be filled by overload rules and their size will
   grow incrementally, taking up more memory. Sometimes an IP address that is
   blocked is a dynamically assigned one, which has since been assigned to a
   host who has a legitimate reason to communicate with hosts in the local
   network.

   For situations like these, pfctl provides the ability to expire table
   entries. For example, this command will remove <bruteforce> table entries
   which have not been referenced for 86400 seconds:

 # pfctl -t bruteforce -T expire 86400

   Similar functionality is provided by security/expiretable, which removes
   table entries which have not been accessed for a specified period of time.

   Once installed, expiretable can be run to remove <bruteforce> table
   entries older than a specified age. This example removes all entries older
   than 24 hours:

 /usr/local/sbin/expiretable -v -d -t 24h bruteforce

    31.3.2.6. Protecting Against SPAM

   Not to be confused with the spamd daemon which comes bundled with
   spamassassin, mail/spamd can be configured with PF to provide an outer
   defense against SPAM. This spamd hooks into the PF configuration using a
   set of redirections.

   Spammers tend to send a large number of messages, and SPAM is mainly sent
   from a few spammer friendly networks and a large number of hijacked
   machines, both of which are reported to blacklists fairly quickly.

   When an SMTP connection from an address in a blacklist is received, spamd
   presents its banner and immediately switches to a mode where it answers
   SMTP traffic one byte at a time. This technique, which is intended to
   waste as much time as possible on the spammer's end, is called tarpitting.
   The specific implementation which uses one byte SMTP replies is often
   referred to as stuttering.

   This example demonstrates the basic procedure for setting up spamd with
   automatically updated blacklists. Refer to the man pages which are
   installed with mail/spamd for more information.

   Procedure 31.1. Configuring spamd
    1. Install the mail/spamd package or port. To use spamd's greylisting
       features, fdescfs(5) must be mounted at /dev/fd. Add the following
       line to /etc/fstab:

  fdescfs /dev/fd fdescfs rw 0 0

       Then, mount the filesystem:

 # mount fdescfs

    2. Next, edit the PF ruleset to include:

 table <spamd> persist
 table <spamd-white> persist
 rdr pass on $ext_if inet proto tcp from <spamd> to \
     { $ext_if, $localnet } port smtp -> 127.0.0.1 port 8025
 rdr pass on $ext_if inet proto tcp from !<spamd-white> to \
     { $ext_if, $localnet } port smtp -> 127.0.0.1 port 8025

       The two tables <spamd> and <spamd-white> are essential. SMTP traffic
       from an address listed in <spamd> but not in <spamd-white> is
       redirected to the spamd daemon listening at port 8025.

    3. The next step is to configure spamd in /usr/local/etc/spamd.conf and
       to add some rc.conf parameters.

       The installation of mail/spamd includes a sample configuration file
       (/usr/local/etc/spamd.conf.sample) and a man page for spamd.conf.
       Refer to these for additional configuration options beyond those shown
       in this example.

       One of the first lines in the configuration file that does not begin
       with a # comment sign contains the block which defines the all list,
       which specifies the lists to use:

 all:\
     :traplist:whitelist:

       This entry adds the desired blacklists, separated by colons (:). To
       use a whitelist to subtract addresses from a blacklist, add the name
       of the whitelist immediately after the name of that blacklist. For
       example: :blacklist:whitelist:.

       This is followed by the specified blacklist's definition:

 traplist:\
     :black:\
     :msg="SPAM. Your address %A has sent spam within the last 24 hours":\
     :method=http:\
     :file=www.openbsd.org/spamd/traplist.gz

       where the first line is the name of the blacklist and the second line
       specifies the list type. The msg field contains the message to display
       to blacklisted senders during the SMTP dialogue. The method field
       specifies how spamd-setup fetches the list data; supported methods are
       http, ftp, from a file in a mounted file system, and via exec of an
       external program. Finally, the file field specifies the name of the
       file spamd expects to receive.

       The definition of the specified whitelist is similar, but omits the
       msg field since a message is not needed:

 whitelist:\
     :white:\
     :method=file:\
     :file=/var/mail/whitelist.txt

  Choose Data Sources with Care:

       Using all the blacklists in the sample spamd.conf will blacklist large
       blocks of the Internet. Administrators need to edit the file to create
       an optimal configuration which uses applicable data sources and, when
       necessary, uses custom lists.

       Next, add this entry to /etc/rc.conf. Additional flags are described
       in the man page specified by the comment:

 spamd_flags="-v" # use "" and see spamd-setup(8) for flags

       When finished, reload the ruleset, start spamd by typing service
       obspamd start, and complete the configuration using spamd-setup.
       Finally, create a cron(8) job which calls spamd-setup to update the
       tables at reasonable intervals.

   On a typical gateway in front of a mail server, hosts will soon start
   getting trapped within a few seconds to several minutes.

   PF also supports greylisting, which temporarily rejects messages from
   unknown hosts with 45n codes. Messages from greylisted hosts which try
   again within a reasonable time are let through. Traffic from senders which
   are set up to behave within the limits set by RFC 1123 and RFC 2821 are
   immediately let through.

   More information about greylisting as a technique can be found at the
   greylisting.org web site. The most amazing thing about greylisting, apart
   from its simplicity, is that it still works. Spammers and malware writers
   have been very slow to adapt to bypass this technique.

   The basic procedure for configuring greylisting is as follows:

   Procedure 31.2. Configuring Greylisting
    1. Make sure that fdescfs(5) is mounted as described in Step 1 of the
       previous Procedure.

    2. To run spamd in greylisting mode, add this line to /etc/rc.conf:

 spamd_grey="YES"  # use spamd greylisting if YES

       Refer to the spamd man page for descriptions of additional related
       parameters.

    3. To complete the greylisting setup:

 # service obspamd restart
 # service obspamlogd start

   Behind the scenes, the spamdb database tool and the spamlogd whitelist
   updater perform essential functions for the greylisting feature. spamdb is
   the administrator's main interface to managing the black, grey, and white
   lists via the contents of the /var/db/spamdb database.

    31.3.2.7. Network Hygiene

   This section describes how block-policy, scrub, and antispoof can be used
   to make the ruleset behave sanely.

   The block-policy is an option which can be set in the options part of the
   ruleset, which precedes the redirection and filtering rules. This option
   determines which feedback, if any, PF sends to hosts that are blocked by a
   rule. The option has two possible values: drop drops blocked packets with
   no feedback, and return returns a status code such as Connection refused.

   If not set, the default policy is drop. To change the block-policy,
   specify the desired value:

 set block-policy return

   In PF, scrub is a keyword which enables network packet normalization. This
   process reassembles fragmented packets and drops TCP packets that have
   invalid flag combinations. Enabling scrub provides a measure of protection
   against certain kinds of attacks based on incorrect handling of packet
   fragments. A number of options are available, but the simplest form is
   suitable for most configurations:

 scrub in all

   Some services, such as NFS, require specific fragment handling options.
   Refer to https://home.nuug.no/~peter/pf/en/scrub.html for more
   information.

   This example reassembles fragments, clears the "do not fragment" bit, and
   sets the maximum segment size to 1440 bytes:

 scrub in all fragment reassemble no-df max-mss 1440

   The antispoof mechanism protects against activity from spoofed or forged
   IP addresses, mainly by blocking packets appearing on interfaces and in
   directions which are logically not possible.

   These rules weed out spoofed traffic coming in from the rest of the world
   as well as any spoofed packets which originate in the local network:

 antispoof for $ext_if
 antispoof for $int_if

    31.3.2.8. Handling Non-Routable Addresses

   Even with a properly configured gateway to handle network address
   translation, one may have to compensate for other people's
   misconfigurations. A common misconfiguration is to let traffic with
   non-routable addresses out to the Internet. Since traffic from
   non-routeable addresses can play a part in several DoS attack techniques,
   consider explicitly blocking traffic from non-routeable addresses from
   entering the network through the external interface.

   In this example, a macro containing non-routable addresses is defined,
   then used in blocking rules. Traffic to and from these addresses is
   quietly dropped on the gateway's external interface.

 martians = "{ 127.0.0.0/8, 192.168.0.0/16, 172.16.0.0/12, \
               10.0.0.0/8, 169.254.0.0/16, 192.0.2.0/24, \
               0.0.0.0/8, 240.0.0.0/4 }"

 block drop in quick on $ext_if from $martians to any
 block drop out quick on $ext_if from any to $martians

  31.3.3. Enabling ALTQ

   On FreeBSD, ALTQ can be used with PF to provide Quality of Service (QOS).
   Once ALTQ is enabled, queues can be defined in the ruleset which determine
   the processing priority of outbound packets.

   Before enabling ALTQ, refer to altq(4) to determine if the drivers for the
   network cards installed on the system support it.

   ALTQ is not available as a loadable kernel module. If the system's
   interfaces support ALTQ, create a custom kernel using the instructions in
   Chapter 8, Configuring the FreeBSD Kernel. The following kernel options
   are available. The first is needed to enable ALTQ. At least one of the
   other options is necessary to specify the queueing scheduler algorithm:

 options         ALTQ
 options         ALTQ_CBQ        # Class Based Queuing (CBQ)
 options         ALTQ_RED        # Random Early Detection (RED)
 options         ALTQ_RIO        # RED In/Out
 options         ALTQ_HFSC       # Hierarchical Packet Scheduler (HFSC)
 options         ALTQ_PRIQ       # Priority Queuing (PRIQ)

   The following scheduler algorithms are available:

   CBQ

           Class Based Queuing (CBQ) is used to divide a connection's
           bandwidth into different classes or queues to prioritize traffic
           based on filter rules.

   RED

           Random Early Detection (RED) is used to avoid network congestion
           by measuring the length of the queue and comparing it to the
           minimum and maximum thresholds for the queue. When the queue is
           over the maximum, all new packets are randomly dropped.

   RIO

           In Random Early Detection In and Out (RIO) mode, RED maintains
           multiple average queue lengths and multiple threshold values, one
           for each QOS level.

   HFSC

           Hierarchical Fair Service Curve Packet Scheduler (HFSC) is
           described in http://www-2.cs.cmu.edu/~hzhang/HFSC/main.html.

   PRIQ

           Priority Queuing (PRIQ) always passes traffic that is in a higher
           queue first.

   More information about the scheduling algorithms and example rulesets are
   available at the OpenBSD's web archive.

31.4. IPFW

   IPFW is a stateful firewall written for FreeBSD which supports both IPv4
   and IPv6. It is comprised of several components: the kernel firewall
   filter rule processor and its integrated packet accounting facility, the
   logging facility, NAT, the dummynet(4) traffic shaper, a forward facility,
   a bridge facility, and an ipstealth facility.

   FreeBSD provides a sample ruleset in /etc/rc.firewall which defines
   several firewall types for common scenarios to assist novice users in
   generating an appropriate ruleset. IPFW provides a powerful syntax which
   advanced users can use to craft customized rulesets that meet the security
   requirements of a given environment.

   This section describes how to enable IPFW, provides an overview of its
   rule syntax, and demonstrates several rulesets for common configuration
   scenarios.

  31.4.1. Enabling IPFW

   IPFW is included in the basic FreeBSD install as a kernel loadable module,
   meaning that a custom kernel is not needed in order to enable IPFW.

   For those users who wish to statically compile IPFW support into a custom
   kernel, see Section 31.4.6, "IPFW Kernel Options".

   To configure the system to enable IPFW at boot time, add
   firewall_enable="YES" to /etc/rc.conf:

 # sysrc firewall_enable="YES"

   To use one of the default firewall types provided by FreeBSD, add another
   line which specifies the type:

 # sysrc firewall_type="open"

   The available types are:

     * open: passes all traffic.

     * client: protects only this machine.

     * simple: protects the whole network.

     * closed: entirely disables IP traffic except for the loopback
       interface.

     * workstation: protects only this machine using stateful rules.

     * UNKNOWN: disables the loading of firewall rules.

     * filename: full path of the file containing the firewall ruleset.

   If firewall_type is set to either client or simple, modify the default
   rules found in /etc/rc.firewall to fit the configuration of the system.

   Note that the filename type is used to load a custom ruleset.

   An alternate way to load a custom ruleset is to set the firewall_script
   variable to the absolute path of an executable script that includes IPFW
   commands. The examples used in this section assume that the
   firewall_script is set to /etc/ipfw.rules:

 # sysrc firewall_script="/etc/ipfw.rules"

   To enable logging through syslogd(8), include this line:

 # sysrc firewall_logging="YES"

  Warning:

   Only firewall rules with the log option will be logged. The default rules
   do not include this option and it must be manually added. Therefore it is
   advisable that the default ruleset is edited for logging. In addition, log
   rotation may be desired if the logs are stored in a separate file.

   There is no /etc/rc.conf variable to set logging limits. To limit the
   number of times a rule is logged per connection attempt, specify the
   number using this line in /etc/sysctl.conf:

 # echo "net.inet.ip.fw.verbose_limit=5" >> /etc/sysctl.conf

   To enable logging through a dedicated interface named ipfw0, add this line
   to /etc/rc.conf instead:

 # sysrc firewall_logif="YES"

   Then use tcpdump to see what is being logged:

 # tcpdump -t -n -i ipfw0

  Tip:

   There is no overhead due to logging unless tcpdump is attached.

   After saving the needed edits, start the firewall. To enable logging
   limits now, also set the sysctl value specified above:

 # service ipfw start
 # sysctl net.inet.ip.fw.verbose_limit=5

  31.4.2. IPFW Rule Syntax

   When a packet enters the IPFW firewall, it is compared against the first
   rule in the ruleset and progresses one rule at a time, moving from top to
   bottom in sequence. When the packet matches the selection parameters of a
   rule, the rule's action is executed and the search of the ruleset
   terminates for that packet. This is referred to as "first match wins". If
   the packet does not match any of the rules, it gets caught by the
   mandatory IPFW default rule number 65535, which denies all packets and
   silently discards them. However, if the packet matches a rule that
   contains the count, skipto, or tee keywords, the search continues. Refer
   to ipfw(8) for details on how these keywords affect rule processing.

   When creating an IPFW rule, keywords must be written in the following
   order. Some keywords are mandatory while other keywords are optional. The
   words shown in uppercase represent a variable and the words shown in
   lowercase must precede the variable that follows it. The # symbol is used
   to mark the start of a comment and may appear at the end of a rule or on
   its own line. Blank lines are ignored.

   CMD RULE_NUMBER set SET_NUMBER ACTION log LOG_AMOUNT PROTO from SRC
   SRC_PORT to DST DST_PORT OPTIONS

   This section provides an overview of these keywords and their options. It
   is not an exhaustive list of every possible option. Refer to ipfw(8) for a
   complete description of the rule syntax that can be used when creating
   IPFW rules.

   CMD

           Every rule must start with ipfw add.

   RULE_NUMBER

           Each rule is associated with a number from 1 to 65534. The number
           is used to indicate the order of rule processing. Multiple rules
           can have the same number, in which case they are applied according
           to the order in which they have been added.

   SET_NUMBER

           Each rule is associated with a set number from 0 to 31. Sets can
           be individually disabled or enabled, making it possible to quickly
           add or delete a set of rules. If a SET_NUMBER is not specified,
           the rule will be added to set 0.

   ACTION

           A rule can be associated with one of the following actions. The
           specified action will be executed when the packet matches the
           selection criterion of the rule.

           allow | accept | pass | permit: these keywords are equivalent and
           allow packets that match the rule.

           check-state: checks the packet against the dynamic state table. If
           a match is found, execute the action associated with the rule
           which generated this dynamic rule, otherwise move to the next
           rule. A check-state rule does not have selection criterion. If no
           check-state rule is present in the ruleset, the dynamic rules
           table is checked at the first keep-state or limit rule.

           count: updates counters for all packets that match the rule. The
           search continues with the next rule.

           deny | drop: either word silently discards packets that match this
           rule.

           Additional actions are available. Refer to ipfw(8) for details.

   LOG_AMOUNT

           When a packet matches a rule with the log keyword, a message will
           be logged to syslogd(8) with a facility name of SECURITY. Logging
           only occurs if the number of packets logged for that particular
           rule does not exceed a specified LOG_AMOUNT. If no LOG_AMOUNT is
           specified, the limit is taken from the value of
           net.inet.ip.fw.verbose_limit. A value of zero removes the logging
           limit. Once the limit is reached, logging can be re-enabled by
           clearing the logging counter or the packet counter for that rule,
           using ipfw resetlog.

  Note:

           Logging is done after all other packet matching conditions have
           been met, and before performing the final action on the packet.
           The administrator decides which rules to enable logging on.

   PROTO

           This optional value can be used to specify any protocol name or
           number found in /etc/protocols.

   SRC

           The from keyword must be followed by the source address or a
           keyword that represents the source address. An address can be
           represented by any, me (any address configured on an interface on
           this system), me6, (any IPv6 address configured on an interface on
           this system), or table followed by the number of a lookup table
           which contains a list of addresses. When specifying an IP address,
           it can be optionally followed by its CIDR mask or subnet mask. For
           example, 1.2.3.4/25 or 1.2.3.4:255.255.255.128.

   SRC_PORT

           An optional source port can be specified using the port number or
           name from /etc/services.

   DST

           The to keyword must be followed by the destination address or a
           keyword that represents the destination address. The same keywords
           and addresses described in the SRC section can be used to describe
           the destination.

   DST_PORT

           An optional destination port can be specified using the port
           number or name from /etc/services.

   OPTIONS

           Several keywords can follow the source and destination. As the
           name suggests, OPTIONS are optional. Commonly used options include
           in or out, which specify the direction of packet flow, icmptypes
           followed by the type of ICMP message, and keep-state.

           When a keep-state rule is matched, the firewall will create a
           dynamic rule which matches bidirectional traffic between the
           source and destination addresses and ports using the same
           protocol.

           The dynamic rules facility is vulnerable to resource depletion
           from a SYN-flood attack which would open a huge number of dynamic
           rules. To counter this type of attack with IPFW, use limit. This
           option limits the number of simultaneous sessions by checking the
           open dynamic rules, counting the number of times this rule and IP
           address combination occurred. If this count is greater than the
           value specified by limit, the packet is discarded.

           Dozens of OPTIONS are available. Refer to ipfw(8) for a
           description of each available option.

  31.4.3. Example Ruleset

   This section demonstrates how to create an example stateful firewall
   ruleset script named /etc/ipfw.rules. In this example, all connection
   rules use in or out to clarify the direction. They also use via
   interface-name to specify the interface the packet is traveling over.

  Note:

   When first creating or testing a firewall ruleset, consider temporarily
   setting this tunable:

 net.inet.ip.fw.default_to_accept="1"

   This sets the default policy of ipfw(8) to be more permissive than the
   default deny ip from any to any, making it slightly more difficult to get
   locked out of the system right after a reboot.

   The firewall script begins by indicating that it is a Bourne shell script
   and flushes any existing rules. It then creates the cmd variable so that
   ipfw add does not have to be typed at the beginning of every rule. It also
   defines the pif variable which represents the name of the interface that
   is attached to the Internet.

 #!/bin/sh
 # Flush out the list before we begin.
 ipfw -q -f flush

 # Set rules command prefix
 cmd="ipfw -q add"
 pif="dc0"     # interface name of NIC attached to Internet

   The first two rules allow all traffic on the trusted internal interface
   and on the loopback interface:

 # Change xl0 to LAN NIC interface name
 $cmd 00005 allow all from any to any via xl0

 # No restrictions on Loopback Interface
 $cmd 00010 allow all from any to any via lo0

   The next rule allows the packet through if it matches an existing entry in
   the dynamic rules table:

 $cmd 00101 check-state

   The next set of rules defines which stateful connections internal systems
   can create to hosts on the Internet:

 # Allow access to public DNS
 # Replace x.x.x.x with the IP address of a public DNS server
 # and repeat for each DNS server in /etc/resolv.conf
 $cmd 00110 allow tcp from any to x.x.x.x 53 out via $pif setup keep-state
 $cmd 00111 allow udp from any to x.x.x.x 53 out via $pif keep-state

 # Allow access to ISP's DHCP server for cable/DSL configurations.
 # Use the first rule and check log for IP address.
 # Then, uncomment the second rule, input the IP address, and delete the first rule
 $cmd 00120 allow log udp from any to any 67 out via $pif keep-state
 #$cmd 00120 allow udp from any to x.x.x.x 67 out via $pif keep-state

 # Allow outbound HTTP and HTTPS connections
 $cmd 00200 allow tcp from any to any 80 out via $pif setup keep-state
 $cmd 00220 allow tcp from any to any 443 out via $pif setup keep-state

 # Allow outbound email connections
 $cmd 00230 allow tcp from any to any 25 out via $pif setup keep-state
 $cmd 00231 allow tcp from any to any 110 out via $pif setup keep-state

 # Allow outbound ping
 $cmd 00250 allow icmp from any to any out via $pif keep-state

 # Allow outbound NTP
 $cmd 00260 allow udp from any to any 123 out via $pif keep-state

 # Allow outbound SSH
 $cmd 00280 allow tcp from any to any 22 out via $pif setup keep-state

 # deny and log all other outbound connections
 $cmd 00299 deny log all from any to any out via $pif

   The next set of rules controls connections from Internet hosts to the
   internal network. It starts by denying packets typically associated with
   attacks and then explicitly allows specific types of connections. All the
   authorized services that originate from the Internet use limit to prevent
   flooding.

 # Deny all inbound traffic from non-routable reserved address spaces
 $cmd 00300 deny all from 192.168.0.0/16 to any in via $pif     #RFC 1918 private IP
 $cmd 00301 deny all from 172.16.0.0/12 to any in via $pif      #RFC 1918 private IP
 $cmd 00302 deny all from 10.0.0.0/8 to any in via $pif         #RFC 1918 private IP
 $cmd 00303 deny all from 127.0.0.0/8 to any in via $pif        #loopback
 $cmd 00304 deny all from 0.0.0.0/8 to any in via $pif          #loopback
 $cmd 00305 deny all from 169.254.0.0/16 to any in via $pif     #DHCP auto-config
 $cmd 00306 deny all from 192.0.2.0/24 to any in via $pif       #reserved for docs
 $cmd 00307 deny all from 204.152.64.0/23 to any in via $pif    #Sun cluster interconnect
 $cmd 00308 deny all from 224.0.0.0/3 to any in via $pif        #Class D & E multicast

 # Deny public pings
 $cmd 00310 deny icmp from any to any in via $pif

 # Deny ident
 $cmd 00315 deny tcp from any to any 113 in via $pif

 # Deny all Netbios services.
 $cmd 00320 deny tcp from any to any 137 in via $pif
 $cmd 00321 deny tcp from any to any 138 in via $pif
 $cmd 00322 deny tcp from any to any 139 in via $pif
 $cmd 00323 deny tcp from any to any 81 in via $pif

 # Deny fragments
 $cmd 00330 deny all from any to any frag in via $pif

 # Deny ACK packets that did not match the dynamic rule table
 $cmd 00332 deny tcp from any to any established in via $pif

 # Allow traffic from ISP's DHCP server.
 # Replace x.x.x.x with the same IP address used in rule 00120.
 #$cmd 00360 allow udp from any to x.x.x.x 67 in via $pif keep-state

 # Allow HTTP connections to internal web server
 $cmd 00400 allow tcp from any to me 80 in via $pif setup limit src-addr 2

 # Allow inbound SSH connections
 $cmd 00410 allow tcp from any to me 22 in via $pif setup limit src-addr 2

 # Reject and log all other incoming connections
 $cmd 00499 deny log all from any to any in via $pif

   The last rule logs all packets that do not match any of the rules in the
   ruleset:

 # Everything else is denied and logged
 $cmd 00999 deny log all from any to any

  31.4.4. In-kernel NAT

   Contributed by Chern Lee.
   Rewritten and updated by Dries Michiels.

   FreeBSD's IPFW firewall has two implementations of NAT: the userland
   implementation natd(8), and the more recent in-kernel NAT implementation.
   Both work in conjunction with IPFW to provide network address translation.
   This can be used to provide an Internet Connection Sharing solution so
   that several internal computers can connect to the Internet using a single
   public IP address.

   To do this, the FreeBSD machine connected to the Internet must act as a
   gateway. This system must have two NICs, where one is connected to the
   Internet and the other is connected to the internal LAN. Each machine
   connected to the LAN should be assigned an IP address in the private
   network space, as defined by RFC 1918.

   Some additional configuration is needed in order to enable the in-kernel
   NAT facility of IPFW. To enable in-kernel NAT support at boot time, the
   following must be set in /etc/rc.conf:

 gateway_enable="YES"
 firewall_enable="YES"
 firewall_nat_enable="YES"

  Note:

   When firewall_nat_enable is set but firewall_enable is not, it will have
   no effect and do nothing. This is because the in-kernel NAT implementation
   is only compatible with IPFW.

   When the ruleset contains stateful rules, the positioning of the NAT rule
   is critical and the skipto action is used. The skipto action requires a
   rule number so that it knows which rule to jump to. The example below
   builds upon the firewall ruleset shown in the previous section. It adds
   some additional entries and modifies some existing rules in order to
   configure the firewall for in-kernel NAT. It starts by adding some
   additional variables which represent the rule number to skip to, the
   keep-state option, and a list of TCP ports which will be used to reduce
   the number of rules.

 #!/bin/sh
 ipfw -q -f flush
 cmd="ipfw -q add"
 skip="skipto 1000"
 pif=dc0
 ks="keep-state"
 good_tcpo="22,25,37,53,80,443,110"

   With in-kernel NAT it is necessary to disable TCP segmentation offloading
   (TSO) due to the architecture of libalias(3), a library implemented as a
   kernel module to provide the in-kernel NAT facility of IPFW. TSO can be
   disabled on a per network interface basis using ifconfig(8) or on a system
   wide basis using sysctl(8). To disable TSO system wide, the following must
   be set it /etc/sysctl.conf:

 net.inet.tcp.tso="0"

   A NAT instance will also be configured. It is possible to have multiple
   NAT instances each with their own configuration. For this example only one
   NAT instance is needed, NAT instance number 1. The configuration can take
   a few options such as: if which indicates the public interface, same_ports
   which takes care that alliased ports and local port numbers are mapped the
   same, unreg_only will result in only unregistered (private) address spaces
   to be processed by the NAT instance, and reset which will help to keep a
   functioning NAT instance even when the public IP address of the IPFW
   machine changes. For all possible options that can be passed to a single
   NAT instance configuration consult ipfw(8). When configuring a stateful
   NATing firewall, it is neseccary to allow translated packets to be
   reinjected in the firewall for further processing. This can be achieved by
   disabling one_pass behavior at the start of the firewall script.

 ipfw disable one_pass
 ipfw -q nat 1 config if $pif same_ports unreg_only reset

   The inbound NAT rule is inserted after the two rules which allow all
   traffic on the trusted and loopback interfaces and after the reassemble
   rule but before the check-state rule. It is important that the rule number
   selected for this NAT rule, in this example 100, is higher than the first
   three rules and lower than the check-state rule. Furthermore, because of
   the behavior of in-kernel NAT it is advised to place a reassemble rule
   just before the first NAT rule and after the rules that allow traffic on
   trusted interface. Normally, IP fragmentation should not happen, but when
   dealing with IPSEC/ESP/GRE tunneling traffic it might and the reassembling
   of fragments is necessary before handing the complete packet over to the
   in-kernel NAT facility.

  Note:

   The reassemble rule was not needed with userland natd(8) because the
   internal workings of the IPFW divert action already takes care of
   reassembling packets before delivery to the socket as also stated in
   ipfw(8).

   The NAT instance and rule number used in this example does not match with
   the default NAT instance and rule number created by rc.firewall.
   rc.firewall is a script that sets up the default firewall rules present in
   FreeBSD.

 $cmd 005 allow all from any to any via xl0  # exclude LAN traffic
 $cmd 010 allow all from any to any via lo0  # exclude loopback traffic
 $cmd 099 reass all from any to any in       # reassemble inbound packets
 $cmd 100 nat 1 ip from any to any in via $pif # NAT any inbound packets
 # Allow the packet through if it has an existing entry in the dynamic rules table
 $cmd 101 check-state

   The outbound rules are modified to replace the allow action with the $skip
   variable, indicating that rule processing will continue at rule 1000. The
   seven tcp rules have been replaced by rule 125 as the $good_tcpo variable
   contains the seven allowed outbound ports.

  Note:

   Remember that IPFW's performance is largely determined by the number of
   rules present in the ruleset.

 # Authorized outbound packets
 $cmd 120 $skip udp from any to x.x.x.x 53 out via $pif $ks
 $cmd 121 $skip udp from any to x.x.x.x 67 out via $pif $ks
 $cmd 125 $skip tcp from any to any $good_tcpo out via $pif setup $ks
 $cmd 130 $skip icmp from any to any out via $pif $ks

   The inbound rules remain the same, except for the very last rule which
   removes the via $pif in order to catch both inbound and outbound rules.
   The NAT rule must follow this last outbound rule, must have a higher
   number than that last rule, and the rule number must be referenced by the
   skipto action. In this ruleset, rule number 1000 handles passing all
   packets to our configured instance for NAT processing. The next rule
   allows any packet which has undergone NAT processing to pass.

 $cmd 999 deny log all from any to any
 $cmd 1000 nat 1 ip from any to any out via $pif # skipto location for outbound stateful rules
 $cmd 1001 allow ip from any to any

   In this example, rules 100, 101, 125, 1000, and 1001 control the address
   translation of the outbound and inbound packets so that the entries in the
   dynamic state table always register the private LAN IP address.

   Consider an internal web browser which initializes a new outbound HTTP
   session over port 80. When the first outbound packet enters the firewall,
   it does not match rule 100 because it is headed out rather than in. It
   passes rule 101 because this is the first packet and it has not been
   posted to the dynamic state table yet. The packet finally matches rule 125
   as it is outbound on an allowed port and has a source IP address from the
   internal LAN. On matching this rule, two actions take place. First, the
   keep-state action adds an entry to the dynamic state table and the
   specified action, skipto rule 1000, is executed. Next, the packet
   undergoes NAT and is sent out to the Internet. This packet makes its way
   to the destination web server, where a response packet is generated and
   sent back. This new packet enters the top of the ruleset. It matches rule
   100 and has its destination IP address mapped back to the original
   internal address. It then is processed by the check-state rule, is found
   in the table as an existing session, and is released to the LAN.

   On the inbound side, the ruleset has to deny bad packets and allow only
   authorized services. A packet which matches an inbound rule is posted to
   the dynamic state table and the packet is released to the LAN. The packet
   generated as a response is recognized by the check-state rule as belonging
   to an existing session. It is then sent to rule 1000 to undergo NAT before
   being released to the outbound interface.

  Note:

   Transitioning from userland natd(8) to in-kernel NAT might seem seamless
   at first but there is small catch. When using the GENERIC kernel, IPFW
   will load the libalias.ko kernel module, when firewall_nat_enable is
   enabled in rc.conf. The libalias.ko kernel module only provides basic NAT
   functionality, whereas the userland implementation natd(8) has all NAT
   functionality available in its userland library without any extra
   configuration. All functionality refers to the following kernel modules
   that can additionally be loaded when needed besides the standard
   libalias.ko kernel module: alias_cuseeme.ko, alias_ftp.ko, alias_bbt.ko,
   skinny.ko, irc.ko, alias_pptp.ko and alias_smedia.ko using the kld_list
   directive in rc.conf. If a custom kernel is used, the full functionality
   of the userland library can be compiled in, in the kernel, using the
   options LIBALIAS.

    31.4.4.1. Port Redirection

   The drawback with NAT in general is that the LAN clients are not
   accessible from the Internet. Clients on the LAN can make outgoing
   connections to the world but cannot receive incoming ones. This presents a
   problem if trying to run Internet services on one of the LAN client
   machines. A simple way around this is to redirect selected Internet ports
   on the NAT providing machine to a LAN client.

   For example, an IRC server runs on client A and a web server runs on
   client B. For this to work properly, connections received on ports 6667
   (IRC) and 80 (HTTP) must be redirected to the respective machines.

   With in-kernel NAT all configuration is done in the NAT instance
   configuration. For a full list of options that an in-kernel NAT instance
   can use, consult ipfw(8). The IPFW syntax follows the syntax of natd. The
   syntax for redirect_port is as follows:

 redirect_port proto targetIP:targetPORT[-targetPORT]
   [aliasIP:]aliasPORT[-aliasPORT]
   [remoteIP[:remotePORT[-remotePORT]]]

   To configure the above example setup, the arguments should be:

 redirect_port tcp 192.168.0.2:6667 6667
 redirect_port tcp 192.168.0.3:80 80

   After adding these arguments to the configuration of NAT instance 1 in the
   above ruleset, the TCP ports will be port forwarded to the LAN client
   machines running the IRC and HTTP services.

 ipfw -q nat 1 config if $pif same_ports unreg_only reset \
   redirect_port tcp 192.168.0.2:6667 6667 \
   redirect_port tcp 192.168.0.3:80 80

   Port ranges over individual ports can be indicated with redirect_port. For
   example, tcp 192.168.0.2:2000-3000 2000-3000 would redirect all
   connections received on ports 2000 to 3000 to ports 2000 to 3000 on client
   A.

    31.4.4.2. Address Redirection

   Address redirection is useful if more than one IP address is available.
   Each LAN client can be assigned its own external IP address by ipfw(8),
   which will then rewrite outgoing packets from the LAN clients with the
   proper external IP address and redirects all traffic incoming on that
   particular IP address back to the specific LAN client. This is also known
   as static NAT. For example, if IP addresses 128.1.1.1, 128.1.1.2, and
   128.1.1.3 are available, 128.1.1.1 can be used as the ipfw(8) machine's
   external IP address, while 128.1.1.2 and 128.1.1.3 are forwarded back to
   LAN clients A and B.

   The redirect_address syntax is as below, where localIP is the internal IP
   address of the LAN client, and publicIP the external IP address
   corresponding to the LAN client.

 redirect_address localIP publicIP

   In the example, the arguments would read:

 redirect_address 192.168.0.2 128.1.1.2
 redirect_address 192.168.0.3 128.1.1.3

   Like redirect_port, these arguments are placed in a NAT instance
   configuration. With address redirection, there is no need for port
   redirection, as all data received on a particular IP address is
   redirected.

   The external IP addresses on the ipfw(8) machine must be active and
   aliased to the external interface. Refer to rc.conf(5) for details.

    31.4.4.3. Userspace NAT

   Let us start with a statement: the userspace NAT implementation: natd(8),
   has more overhead than in-kernel NAT. For natd(8) to translate packets,
   the packets have to be copied from the kernel to userspace and back which
   brings in extra overhead that is not present with in-kernel NAT.

   To enable the userpace NAT daemon natd(8) at boot time, the following is a
   minimum configuration in /etc/rc.conf. Where natd_interface is set to the
   name of the NIC attached to the Internet. The rc(8) script of natd(8) will
   automatically check if a dynamic IP address is used and configure itself
   to handle that.

 gateway_enable="YES"
 natd_enable="YES"
 natd_interface="rl0"

   In general, the above ruleset as explained for in-kernel NAT can also be
   used together with natd(8). The exceptions are the configuration of the
   in-kernel NAT instance (ipfw -q nat 1 config ...) which is not needed
   together with reassemble rule 99 because its functionality is included in
   the divert action. Rule number 100 and 1000 will have to change sligthly
   as shown below.

 $cmd 100 divert natd ip from any to any in via $pif
 $cmd 1000 divert natd ip from any to any out via $pif

   To configure port or address redirection, a similar syntax as with
   in-kernel NAT is used. Although, now, instead of specifying the
   configuration in our ruleset script like with in-kernel NAT, configuration
   of natd(8) is best done in a configuration file. To do this, an extra flag
   must be passed via /etc/rc.conf which specifies the path of the
   configuration file.

 natd_flags="-f /etc/natd.conf"

  Note:

   The specified file must contain a list of configuration options, one per
   line. For more information about the configuration file and possible
   variables, consult natd(8). Below are two example entries, one per line:

 redirect_port tcp 192.168.0.2:6667 6667
 redirect_address 192.168.0.3 128.1.1.3

  31.4.5. The IPFW Command

   ipfw can be used to make manual, single rule additions or deletions to the
   active firewall while it is running. The problem with using this method is
   that all the changes are lost when the system reboots. It is recommended
   to instead write all the rules in a file and to use that file to load the
   rules at boot time and to replace the currently running firewall rules
   whenever that file changes.

   ipfw is a useful way to display the running firewall rules to the console
   screen. The IPFW accounting facility dynamically creates a counter for
   each rule that counts each packet that matches the rule. During the
   process of testing a rule, listing the rule with its counter is one way to
   determine if the rule is functioning as expected.

   To list all the running rules in sequence:

 # ipfw list

   To list all the running rules with a time stamp of when the last time the
   rule was matched:

 # ipfw -t list

   The next example lists accounting information and the packet count for
   matched rules along with the rules themselves. The first column is the
   rule number, followed by the number of matched packets and bytes, followed
   by the rule itself.

 # ipfw -a list

   To list dynamic rules in addition to static rules:

 # ipfw -d list

   To also show the expired dynamic rules:

 # ipfw -d -e list

   To zero the counters:

 # ipfw zero

   To zero the counters for just the rule with number NUM:

 # ipfw zero NUM

    31.4.5.1. Logging Firewall Messages

   Even with the logging facility enabled, IPFW will not generate any rule
   logging on its own. The firewall administrator decides which rules in the
   ruleset will be logged, and adds the log keyword to those rules. Normally
   only deny rules are logged. It is customary to duplicate the "ipfw default
   deny everything" rule with the log keyword included as the last rule in
   the ruleset. This way, it is possible to see all the packets that did not
   match any of the rules in the ruleset.

   Logging is a two edged sword. If one is not careful, an over abundance of
   log data or a DoS attack can fill the disk with log files. Log messages
   are not only written to syslogd, but also are displayed on the root
   console screen and soon become annoying.

   The IPFIREWALL_VERBOSE_LIMIT=5 kernel option limits the number of
   consecutive messages sent to syslogd(8), concerning the packet matching of
   a given rule. When this option is enabled in the kernel, the number of
   consecutive messages concerning a particular rule is capped at the number
   specified. There is nothing to be gained from 200 identical log messages.
   With this option set to five, five consecutive messages concerning a
   particular rule would be logged to syslogd and the remainder identical
   consecutive messages would be counted and posted to syslogd with a phrase
   like the following:

 last message repeated 45 times

   All logged packets messages are written by default to /var/log/security,
   which is defined in /etc/syslog.conf.

    31.4.5.2. Building a Rule Script

   Most experienced IPFW users create a file containing the rules and code
   them in a manner compatible with running them as a script. The major
   benefit of doing this is the firewall rules can be refreshed in mass
   without the need of rebooting the system to activate them. This method is
   convenient in testing new rules as the procedure can be executed as many
   times as needed. Being a script, symbolic substitution can be used for
   frequently used values to be substituted into multiple rules.

   This example script is compatible with the syntax used by the sh(1),
   csh(1), and tcsh(1) shells. Symbolic substitution fields are prefixed with
   a dollar sign ($). Symbolic fields do not have the $ prefix. The value to
   populate the symbolic field must be enclosed in double quotes ("").

   Start the rules file like this:

 ############### start of example ipfw rules script #############
 #
 ipfw -q -f flush       # Delete all rules
 # Set defaults
 oif="tun0"             # out interface
 odns="192.0.2.11"      # ISP's DNS server IP address
 cmd="ipfw -q add "     # build rule prefix
 ks="keep-state"        # just too lazy to key this each time
 $cmd 00500 check-state
 $cmd 00502 deny all from any to any frag
 $cmd 00501 deny tcp from any to any established
 $cmd 00600 allow tcp from any to any 80 out via $oif setup $ks
 $cmd 00610 allow tcp from any to $odns 53 out via $oif setup $ks
 $cmd 00611 allow udp from any to $odns 53 out via $oif $ks
 ################### End of example ipfw rules script ############

   The rules are not important as the focus of this example is how the
   symbolic substitution fields are populated.

   If the above example was in /etc/ipfw.rules, the rules could be reloaded
   by the following command:

 # sh /etc/ipfw.rules

   /etc/ipfw.rules can be located anywhere and the file can have any name.

   The same thing could be accomplished by running these commands by hand:

 # ipfw -q -f flush
 # ipfw -q add check-state
 # ipfw -q add deny all from any to any frag
 # ipfw -q add deny tcp from any to any established
 # ipfw -q add allow tcp from any to any 80 out via tun0 setup keep-state
 # ipfw -q add allow tcp from any to 192.0.2.11 53 out via tun0 setup keep-state
 # ipfw -q add 00611 allow udp from any to 192.0.2.11 53 out via tun0 keep-state

  31.4.6. IPFW Kernel Options

   In order to statically compile IPFW support into a custom kernel, refer to
   the instructions in Chapter 8, Configuring the FreeBSD Kernel. The
   following options are available for the custom kernel configuration file:

 options    IPFIREWALL                   # enables IPFW
 options    IPFIREWALL_VERBOSE           # enables logging for rules with log keyword to syslogd(8)
 options    IPFIREWALL_VERBOSE_LIMIT=5   # limits number of logged packets per-entry
 options    IPFIREWALL_DEFAULT_TO_ACCEPT # sets default policy to pass what is not explicitly denied
 options    IPFIREWALL_NAT               # enables basic in-kernel NAT support
 options    LIBALIAS                     # enables full in-kernel NAT support
 options    IPFIREWALL_NAT64             # enables in-kernel NAT64 support
 options    IPFIREWALL_NPTV6             # enables in-kernel IPv6 NPT support
 options    IPFIREWALL_PMOD              # enables protocols modification module support
 options    IPDIVERT                     # enables NAT through natd(8)

  Note:

   IPFW can be loaded as a kernel module: options above are built by default
   as modules or can be set at runtime using tunables.

31.5. IPFILTER (IPF)

   IPFILTER, also known as IPF, is a cross-platform, open source firewall
   which has been ported to several operating systems, including FreeBSD,
   NetBSD, OpenBSD, and Solaris(TM).

   IPFILTER is a kernel-side firewall and NAT mechanism that can be
   controlled and monitored by userland programs. Firewall rules can be set
   or deleted using ipf, NAT rules can be set or deleted using ipnat,
   run-time statistics for the kernel parts of IPFILTER can be printed using
   ipfstat, and ipmon can be used to log IPFILTER actions to the system log
   files.

   IPF was originally written using a rule processing logic of "the last
   matching rule wins" and only used stateless rules. Since then, IPF has
   been enhanced to include the quick and keep state options.

   The IPF FAQ is at http://www.phildev.net/ipf/index.html. A searchable
   archive of the IPFilter mailing list is available at
   http://marc.info/?l=ipfilter.

   This section of the Handbook focuses on IPF as it pertains to FreeBSD. It
   provides examples of rules that contain the quick and keep state options.

  31.5.1. Enabling IPF

   IPF is included in the basic FreeBSD install as a kernel loadable module,
   meaning that a custom kernel is not needed in order to enable IPF.

   For users who prefer to statically compile IPF support into a custom
   kernel, refer to the instructions in Chapter 8, Configuring the FreeBSD
   Kernel. The following kernel options are available:

 options IPFILTER
 options IPFILTER_LOG
 options IPFILTER_LOOKUP
 options IPFILTER_DEFAULT_BLOCK

   where options IPFILTER enables support for IPFILTER, options IPFILTER_LOG
   enables IPF logging using the ipl packet logging pseudo-device for every
   rule that has the log keyword, IPFILTER_LOOKUP enables IP pools in order
   to speed up IP lookups, and options IPFILTER_DEFAULT_BLOCK changes the
   default behavior so that any packet not matching a firewall pass rule gets
   blocked.

   To configure the system to enable IPF at boot time, add the following
   entries to /etc/rc.conf. These entries will also enable logging and
   default pass all. To change the default policy to block all without
   compiling a custom kernel, remember to add a block all rule at the end of
   the ruleset.

 ipfilter_enable="YES"             # Start ipf firewall
 ipfilter_rules="/etc/ipf.rules"   # loads rules definition text file
 ipv6_ipfilter_rules="/etc/ipf6.rules" # loads rules definition text file for IPv6
 ipmon_enable="YES"                # Start IP monitor log
 ipmon_flags="-Ds"                 # D = start as daemon
                                   # s = log to syslog
                                   # v = log tcp window, ack, seq
                                   # n = map IP & port to names

   If NAT functionality is needed, also add these lines:

 gateway_enable="YES"              # Enable as LAN gateway
 ipnat_enable="YES"                # Start ipnat function
 ipnat_rules="/etc/ipnat.rules"    # rules definition file for ipnat

   Then, to start IPF now:

 # service ipfilter start

   To load the firewall rules, specify the name of the ruleset file using
   ipf. The following command can be used to replace the currently running
   firewall rules:

 # ipf -Fa -f /etc/ipf.rules

   where -Fa flushes all the internal rules tables and -f specifies the file
   containing the rules to load.

   This provides the ability to make changes to a custom ruleset and update
   the running firewall with a fresh copy of the rules without having to
   reboot the system. This method is convenient for testing new rules as the
   procedure can be executed as many times as needed.

   Refer to ipf(8) for details on the other flags available with this
   command.

  31.5.2. IPF Rule Syntax

   This section describes the IPF rule syntax used to create stateful rules.
   When creating rules, keep in mind that unless the quick keyword appears in
   a rule, every rule is read in order, with the last matching rule being the
   one that is applied. This means that even if the first rule to match a
   packet is a pass, if there is a later matching rule that is a block, the
   packet will be dropped. Sample rulesets can be found in
   /usr/share/examples/ipfilter.

   When creating rules, a # character is used to mark the start of a comment
   and may appear at the end of a rule, to explain that rule's function, or
   on its own line. Any blank lines are ignored.

   The keywords which are used in rules must be written in a specific order,
   from left to right. Some keywords are mandatory while others are optional.
   Some keywords have sub-options which may be keywords themselves and also
   include more sub-options. The keyword order is as follows, where the words
   shown in uppercase represent a variable and the words shown in lowercase
   must precede the variable that follows it:

   ACTION DIRECTION OPTIONS proto PROTO_TYPE from SRC_ADDR SRC_PORT to
   DST_ADDR DST_PORT TCP_FLAG|ICMP_TYPE keep state STATE

   This section describes each of these keywords and their options. It is not
   an exhaustive list of every possible option. Refer to ipf(5) for a
   complete description of the rule syntax that can be used when creating IPF
   rules and examples for using each keyword.

   ACTION

           The action keyword indicates what to do with the packet if it
           matches that rule. Every rule must have an action. The following
           actions are recognized:

           block: drops the packet.

           pass: allows the packet.

           log: generates a log record.

           count: counts the number of packets and bytes which can provide an
           indication of how often a rule is used.

           auth: queues the packet for further processing by another program.

           call: provides access to functions built into IPF that allow more
           complex actions.

           decapsulate: removes any headers in order to process the contents
           of the packet.

   DIRECTION

           Next, each rule must explicitly state the direction of traffic
           using one of these keywords:

           in: the rule is applied against an inbound packet.

           out: the rule is applied against an outbound packet.

           all: the rule applies to either direction.

           If the system has multiple interfaces, the interface can be
           specified along with the direction. An example would be in on
           fxp0.

   OPTIONS

           Options are optional. However, if multiple options are specified,
           they must be used in the order shown here.

           log: when performing the specified ACTION, the contents of the
           packet's headers will be written to the ipl(4) packet log
           pseudo-device.

           quick: if a packet matches this rule, the ACTION specified by the
           rule occurs and no further processing of any following rules will
           occur for this packet.

           on: must be followed by the interface name as displayed by
           ifconfig(8). The rule will only match if the packet is going
           through the specified interface in the specified direction.

           When using the log keyword, the following qualifiers may be used
           in this order:

           body: indicates that the first 128 bytes of the packet contents
           will be logged after the headers.

           first: if the log keyword is being used in conjunction with a keep
           state option, this option is recommended so that only the
           triggering packet is logged and not every packet which matches the
           stateful connection.

           Additional options are available to specify error return messages.
           Refer to ipf(5) for more details.

   PROTO_TYPE

           The protocol type is optional. However, it is mandatory if the
           rule needs to specify a SRC_PORT or a DST_PORT as it defines the
           type of protocol. When specifying the type of protocol, use the
           proto keyword followed by either a protocol number or name from
           /etc/protocols. Example protocol names include tcp, udp, or icmp.
           If PROTO_TYPE is specified but no SRC_PORT or DST_PORT is
           specified, all port numbers for that protocol will match that
           rule.

   SRC_ADDR

           The from keyword is mandatory and is followed by a keyword which
           represents the source of the packet. The source can be a hostname,
           an IP address followed by the CIDR mask, an address pool, or the
           keyword all. Refer to ipf(5) for examples.

           There is no way to match ranges of IP addresses which do not
           express themselves easily using the dotted numeric form /
           mask-length notation. The net-mgmt/ipcalc package or port may be
           used to ease the calculation of the CIDR mask. Additional
           information is available at the utility's web page:
           http://jodies.de/ipcalc.

   SRC_PORT

           The port number of the source is optional. However, if it is used,
           it requires PROTO_TYPE to be first defined in the rule. The port
           number must also be preceded by the proto keyword.

           A number of different comparison operators are supported: = (equal
           to), != (not equal to), < (less than), > (greater than), <= (less
           than or equal to), and >= (greater than or equal to).

           To specify port ranges, place the two port numbers between <>
           (less than and greater than ), >< (greater than and less than ),
           or : (greater than or equal to and less than or equal to).

   DST_ADDR

           The to keyword is mandatory and is followed by a keyword which
           represents the destination of the packet. Similar to SRC_ADDR, it
           can be a hostname, an IP address followed by the CIDR mask, an
           address pool, or the keyword all.

   DST_PORT

           Similar to SRC_PORT, the port number of the destination is
           optional. However, if it is used, it requires PROTO_TYPE to be
           first defined in the rule. The port number must also be preceded
           by the proto keyword.

   TCP_FLAG|ICMP_TYPE

           If tcp is specified as the PROTO_TYPE, flags can be specified as
           letters, where each letter represents one of the possible TCP
           flags used to determine the state of a connection. Possible values
           are: S (SYN), A (ACK), P (PSH), F (FIN), U (URG), R (RST), C
           (CWN), and E (ECN).

           If icmp is specified as the PROTO_TYPE, the ICMP type to match can
           be specified. Refer to ipf(5) for the allowable types.

   STATE

           If a pass rule contains keep state, IPF will add an entry to its
           dynamic state table and allow subsequent packets that match the
           connection. IPF can track state for TCP, UDP, and ICMP sessions.
           Any packet that IPF can be certain is part of an active session,
           even if it is a different protocol, will be allowed.

           In IPF, packets destined to go out through the interface connected
           to the public Internet are first checked against the dynamic state
           table. If the packet matches the next expected packet comprising
           an active session conversation, it exits the firewall and the
           state of the session conversation flow is updated in the dynamic
           state table. Packets that do not belong to an already active
           session are checked against the outbound ruleset. Packets coming
           in from the interface connected to the public Internet are first
           checked against the dynamic state table. If the packet matches the
           next expected packet comprising an active session, it exits the
           firewall and the state of the session conversation flow is updated
           in the dynamic state table. Packets that do not belong to an
           already active session are checked against the inbound ruleset.

           Several keywords can be added after keep state. If used, these
           keywords set various options that control stateful filtering, such
           as setting connection limits or connection age. Refer to ipf(5)
           for the list of available options and their descriptions.

  31.5.3. Example Ruleset

   This section demonstrates how to create an example ruleset which only
   allows services matching pass rules and blocks all others.

   FreeBSD uses the loopback interface (lo0) and the IP address 127.0.0.1 for
   internal communication. The firewall ruleset must contain rules to allow
   free movement of these internally used packets:

 # no restrictions on loopback interface
 pass in quick on lo0 all
 pass out quick on lo0 all

   The public interface connected to the Internet is used to authorize and
   control access of all outbound and inbound connections. If one or more
   interfaces are cabled to private networks, those internal interfaces may
   require rules to allow packets originating from the LAN to flow between
   the internal networks or to the interface attached to the Internet. The
   ruleset should be organized into three major sections: any trusted
   internal interfaces, outbound connections through the public interface,
   and inbound connections through the public interface.

   These two rules allow all traffic to pass through a trusted LAN interface
   named xl0:

 # no restrictions on inside LAN interface for private network
 pass out quick on xl0 all
 pass in quick on xl0 all

   The rules for the public interface's outbound and inbound sections should
   have the most frequently matched rules placed before less commonly matched
   rules, with the last rule in the section blocking and logging all packets
   for that interface and direction.

   This set of rules defines the outbound section of the public interface
   named dc0. These rules keep state and identify the specific services that
   internal systems are authorized for public Internet access. All the rules
   use quick and specify the appropriate port numbers and, where applicable,
   destination addresses.

 # interface facing Internet (outbound)
 # Matches session start requests originating from or behind the
 # firewall, destined for the Internet.

 # Allow outbound access to public DNS servers.
 # Replace x.x.x. with address listed in /etc/resolv.conf.
 # Repeat for each DNS server.
 pass out quick on dc0 proto tcp from any to x.x.x. port = 53 flags S keep state
 pass out quick on dc0 proto udp from any to xxx port = 53 keep state

 # Allow access to ISP's specified DHCP server for cable or DSL networks.
 # Use the first rule, then check log for the IP address of DHCP server.
 # Then, uncomment the second rule, replace z.z.z.z with the IP address,
 # and comment out the first rule
 pass out log quick on dc0 proto udp from any to any port = 67 keep state
 #pass out quick on dc0 proto udp from any to z.z.z.z port = 67 keep state

 # Allow HTTP and HTTPS
 pass out quick on dc0 proto tcp from any to any port = 80 flags S keep state
 pass out quick on dc0 proto tcp from any to any port = 443 flags S keep state

 # Allow email
 pass out quick on dc0 proto tcp from any to any port = 110 flags S keep state
 pass out quick on dc0 proto tcp from any to any port = 25 flags S keep state

 # Allow NTP
 pass out quick on dc0 proto tcp from any to any port = 37 flags S keep state

 # Allow FTP
 pass out quick on dc0 proto tcp from any to any port = 21 flags S keep state

 # Allow SSH
 pass out quick on dc0 proto tcp from any to any port = 22 flags S keep state

 # Allow ping
 pass out quick on dc0 proto icmp from any to any icmp-type 8 keep state

 # Block and log everything else
 block out log first quick on dc0 all

   This example of the rules in the inbound section of the public interface
   blocks all undesirable packets first. This reduces the number of packets
   that are logged by the last rule.

 # interface facing Internet (inbound)
 # Block all inbound traffic from non-routable or reserved address spaces
 block in quick on dc0 from 192.168.0.0/16 to any    #RFC 1918 private IP
 block in quick on dc0 from 172.16.0.0/12 to any     #RFC 1918 private IP
 block in quick on dc0 from 10.0.0.0/8 to any        #RFC 1918 private IP
 block in quick on dc0 from 127.0.0.0/8 to any       #loopback
 block in quick on dc0 from 0.0.0.0/8 to any         #loopback
 block in quick on dc0 from 169.254.0.0/16 to any    #DHCP auto-config
 block in quick on dc0 from 192.0.2.0/24 to any      #reserved for docs
 block in quick on dc0 from 204.152.64.0/23 to any   #Sun cluster interconnect
 block in quick on dc0 from 224.0.0.0/3 to any       #Class D & E multicast

 # Block fragments and too short tcp packets
 block in quick on dc0 all with frags
 block in quick on dc0 proto tcp all with short

 # block source routed packets
 block in quick on dc0 all with opt lsrr
 block in quick on dc0 all with opt ssrr

 # Block OS fingerprint attempts and log first occurrence
 block in log first quick on dc0 proto tcp from any to any flags FUP

 # Block anything with special options
 block in quick on dc0 all with ipopts

 # Block public pings and ident
 block in quick on dc0 proto icmp all icmp-type 8
 block in quick on dc0 proto tcp from any to any port = 113

 # Block incoming Netbios services
 block in log first quick on dc0 proto tcp/udp from any to any port = 137
 block in log first quick on dc0 proto tcp/udp from any to any port = 138
 block in log first quick on dc0 proto tcp/udp from any to any port = 139
 block in log first quick on dc0 proto tcp/udp from any to any port = 81

   Any time there are logged messages on a rule with the log first option,
   run ipfstat -hio to evaluate how many times the rule has been matched. A
   large number of matches may indicate that the system is under attack.

   The rest of the rules in the inbound section define which connections are
   allowed to be initiated from the Internet. The last rule denies all
   connections which were not explicitly allowed by previous rules in this
   section.

 # Allow traffic in from ISP's DHCP server. Replace z.z.z.z with
 # the same IP address used in the outbound section.
 pass in quick on dc0 proto udp from z.z.z.z to any port = 68 keep state

 # Allow public connections to specified internal web server
 pass in quick on dc0 proto tcp from any to x.x.x.x port = 80 flags S keep state

 # Block and log only first occurrence of all remaining traffic.
 block in log first quick on dc0 all

  31.5.4. Configuring NAT

   To enable NAT, add these statements to /etc/rc.conf and specify the name
   of the file containing the NAT rules:

 gateway_enable="YES"
 ipnat_enable="YES"
 ipnat_rules="/etc/ipnat.rules"

   NAT rules are flexible and can accomplish many different things to fit the
   needs of both commercial and home users. The rule syntax presented here
   has been simplified to demonstrate common usage. For a complete rule
   syntax description, refer to ipnat(5).

   The basic syntax for a NAT rule is as follows, where map starts the rule
   and IF should be replaced with the name of the external interface:

 map IF LAN_IP_RANGE -> PUBLIC_ADDRESS

   The LAN_IP_RANGE is the range of IP addresses used by internal clients.
   Usually, it is a private address range such as 192.168.1.0/24. The
   PUBLIC_ADDRESS can either be the static external IP address or the keyword
   0/32 which represents the IP address assigned to IF.

   In IPF, when a packet arrives at the firewall from the LAN with a public
   destination, it first passes through the outbound rules of the firewall
   ruleset. Then, the packet is passed to the NAT ruleset which is read from
   the top down, where the first matching rule wins. IPF tests each NAT rule
   against the packet's interface name and source IP address. When a packet's
   interface name matches a NAT rule, the packet's source IP address in the
   private LAN is checked to see if it falls within the IP address range
   specified in LAN_IP_RANGE. On a match, the packet has its source IP
   address rewritten with the public IP address specified by PUBLIC_ADDRESS.
   IPF posts an entry in its internal NAT table so that when the packet
   returns from the Internet, it can be mapped back to its original private
   IP address before being passed to the firewall rules for further
   processing.

   For networks that have large numbers of internal systems or multiple
   subnets, the process of funneling every private IP address into a single
   public IP address becomes a resource problem. Two methods are available to
   relieve this issue.

   The first method is to assign a range of ports to use as source ports. By
   adding the portmap keyword, NAT can be directed to only use source ports
   in the specified range:

 map dc0 192.168.1.0/24 -> 0/32 portmap tcp/udp 20000:60000

   Alternately, use the auto keyword which tells NAT to determine the ports
   that are available for use:

 map dc0 192.168.1.0/24 -> 0/32 portmap tcp/udp auto

   The second method is to use a pool of public addresses. This is useful
   when there are too many LAN addresses to fit into a single public address
   and a block of public IP addresses is available. These public addresses
   can be used as a pool from which NAT selects an IP address as a packet's
   address is mapped on its way out.

   The range of public IP addresses can be specified using a netmask or CIDR
   notation. These two rules are equivalent:

 map dc0 192.168.1.0/24 -> 204.134.75.0/255.255.255.0
 map dc0 192.168.1.0/24 -> 204.134.75.0/24

   A common practice is to have a publically accessible web server or mail
   server segregated to an internal network segment. The traffic from these
   servers still has to undergo NAT, but port redirection is needed to direct
   inbound traffic to the correct server. For example, to map a web server
   using the internal address 10.0.10.25 to its public IP address of
   20.20.20.5, use this rule:

 rdr dc0 20.20.20.5/32 port 80 -> 10.0.10.25 port 80

   If it is the only web server, this rule would also work as it redirects
   all external HTTP requests to 10.0.10.25:

 rdr dc0 0.0.0.0/0 port 80 -> 10.0.10.25 port 80

   IPF has a built in FTP proxy which can be used with NAT. It monitors all
   outbound traffic for active or passive FTP connection requests and
   dynamically creates temporary filter rules containing the port number used
   by the FTP data channel. This eliminates the need to open large ranges of
   high order ports for FTP connections.

   In this example, the first rule calls the proxy for outbound FTP traffic
   from the internal LAN. The second rule passes the FTP traffic from the
   firewall to the Internet, and the third rule handles all non-FTP traffic
   from the internal LAN:

 map dc0 10.0.10.0/29 -> 0/32 proxy port 21 ftp/tcp
 map dc0 0.0.0.0/0 -> 0/32 proxy port 21 ftp/tcp
 map dc0 10.0.10.0/29 -> 0/32

   The FTP map rules go before the NAT rule so that when a packet matches an
   FTP rule, the FTP proxy creates temporary filter rules to let the FTP
   session packets pass and undergo NAT. All LAN packets that are not FTP
   will not match the FTP rules but will undergo NAT if they match the third
   rule.

   Without the FTP proxy, the following firewall rules would instead be
   needed. Note that without the proxy, all ports above 1024 need to be
   allowed:

 # Allow out LAN PC client FTP to public Internet
 # Active and passive modes
 pass out quick on rl0 proto tcp from any to any port = 21 flags S keep state

 # Allow out passive mode data channel high order port numbers
 pass out quick on rl0 proto tcp from any to any port > 1024 flags S keep state

 # Active mode let data channel in from FTP server
 pass in quick on rl0 proto tcp from any to any port = 20 flags S keep state

   Whenever the file containing the NAT rules is edited, run ipnat with -CF
   to delete the current NAT rules and flush the contents of the dynamic
   translation table. Include -f and specify the name of the NAT ruleset to
   load:

 # ipnat -CF -f /etc/ipnat.rules

   To display the NAT statistics:

 # ipnat -s

   To list the NAT table's current mappings:

 # ipnat -l

   To turn verbose mode on and display information relating to rule
   processing and active rules and table entries:

 # ipnat -v

  31.5.5. Viewing IPF Statistics

   IPF includes ipfstat(8) which can be used to retrieve and display
   statistics which are gathered as packets match rules as they go through
   the firewall. Statistics are accumulated since the firewall was last
   started or since the last time they were reset to zero using ipf -Z.

   The default ipfstat output looks like this:

 input packets: blocked 99286 passed 1255609 nomatch 14686 counted 0
  output packets: blocked 4200 passed 1284345 nomatch 14687 counted 0
  input packets logged: blocked 99286 passed 0
  output packets logged: blocked 0 passed 0
  packets logged: input 0 output 0
  log failures: input 3898 output 0
  fragment state(in): kept 0 lost 0
  fragment state(out): kept 0 lost 0
  packet state(in): kept 169364 lost 0
  packet state(out): kept 431395 lost 0
  ICMP replies: 0 TCP RSTs sent: 0
  Result cache hits(in): 1215208 (out): 1098963
  IN Pullups succeeded: 2 failed: 0
  OUT Pullups succeeded: 0 failed: 0
  Fastroute successes: 0 failures: 0
  TCP cksum fails(in): 0 (out): 0
  Packet log flags set: (0)

   Several options are available. When supplied with either -i for inbound or
   -o for outbound, the command will retrieve and display the appropriate
   list of filter rules currently installed and in use by the kernel. To also
   see the rule numbers, include -n. For example, ipfstat -on displays the
   outbound rules table with rule numbers:

 @1 pass out on xl0 from any to any
 @2 block out on dc0 from any to any
 @3 pass out quick on dc0 proto tcp/udp from any to any keep state

   Include -h to prefix each rule with a count of how many times the rule was
   matched. For example, ipfstat -oh displays the outbound internal rules
   table, prefixing each rule with its usage count:

 2451423 pass out on xl0 from any to any
 354727 block out on dc0 from any to any
 430918 pass out quick on dc0 proto tcp/udp from any to any keep state

   To display the state table in a format similar to top(1), use ipfstat -t.
   When the firewall is under attack, this option provides the ability to
   identify and see the attacking packets. The optional sub-flags give the
   ability to select the destination or source IP, port, or protocol to be
   monitored in real time. Refer to ipfstat(8) for details.

  31.5.6. IPF Logging

   IPF provides ipmon, which can be used to write the firewall's logging
   information in a human readable format. It requires that options
   IPFILTER_LOG be first added to a custom kernel using the instructions in
   Chapter 8, Configuring the FreeBSD Kernel.

   This command is typically run in daemon mode in order to provide a
   continuous system log file so that logging of past events may be reviewed.
   Since FreeBSD has a built in syslogd(8) facility to automatically rotate
   system logs, the default rc.conf ipmon_flags statement uses -Ds:

 ipmon_flags="-Ds" # D = start as daemon
                   # s = log to syslog
                   # v = log tcp window, ack, seq
                   # n = map IP & port to names

   Logging provides the ability to review, after the fact, information such
   as which packets were dropped, what addresses they came from, and where
   they were going. This information is useful in tracking down attackers.

   Once the logging facility is enabled in rc.conf and started with service
   ipmon start, IPF will only log the rules which contain the log keyword.
   The firewall administrator decides which rules in the ruleset should be
   logged and normally only deny rules are logged. It is customary to include
   the log keyword in the last rule in the ruleset. This makes it possible to
   see all the packets that did not match any of the rules in the ruleset.

   By default, ipmon -Ds mode uses local0 as the logging facility. The
   following logging levels can be used to further segregate the logged data:

 LOG_INFO - packets logged using the "log" keyword as the action rather than pass or block.
 LOG_NOTICE - packets logged which are also passed
 LOG_WARNING - packets logged which are also blocked
 LOG_ERR - packets which have been logged and which can be considered short due to an incomplete header

   In order to setup IPF to log all data to /var/log/ipfilter.log, first
   create the empty file:

 # touch /var/log/ipfilter.log

   Then, to write all logged messages to the specified file, add the
   following statement to /etc/syslog.conf:

 local0.* /var/log/ipfilter.log

   To activate the changes and instruct syslogd(8) to read the modified
   /etc/syslog.conf, run service syslogd reload.

   Do not forget to edit /etc/newsyslog.conf to rotate the new log file.

   Messages generated by ipmon consist of data fields separated by white
   space. Fields common to all messages are:

    1. The date of packet receipt.

    2. The time of packet receipt. This is in the form HH:MM:SS.F, for hours,
       minutes, seconds, and fractions of a second.

    3. The name of the interface that processed the packet.

    4. The group and rule number of the rule in the format @0:17.

    5. The action: p for passed, b for blocked, S for a short packet, n did
       not match any rules, and L for a log rule.

    6. The addresses written as three fields: the source address and port
       separated by a comma, the -> symbol, and the destination address and
       port. For example: 209.53.17.22,80 -> 198.73.220.17,1722.

    7. PR followed by the protocol name or number: for example, PR tcp.

    8. len followed by the header length and total length of the packet: for
       example, len 20 40.

   If the packet is a TCP packet, there will be an additional field starting
   with a hyphen followed by letters corresponding to any flags that were
   set. Refer to ipf(5) for a list of letters and their flags.

   If the packet is an ICMP packet, there will be two fields at the end: the
   first always being "icmp" and the next being the ICMP message and
   sub-message type, separated by a slash. For example: icmp 3/3 for a port
   unreachable message.

31.6. Blacklistd

   Blacklistd is a daemon listening to sockets to receive notifications from
   other daemons about connection attempts that failed or were successful. It
   is most widely used in blocking too many connection attempts on open
   ports. A prime example is SSH running on the internet getting a lot of
   requests from bots or scripts trying to guess passwords and gain access.
   Using blacklistd, the daemon can notify the firewall to create a filter
   rule to block excessive connection attempts from a single source after a
   number of tries. Blacklistd was first developed on NetBSD and appeared
   there in version 7. FreeBSD 11 imported blacklistd from NetBSD.

   This chapter describes how to set up blacklistd, configure it, and
   provides examples on how to use it. Readers should be familiar with basic
   firewall concepts like rules. For details, refer to the firewall chapter.
   PF is used in the examples, but other firewalls available on FreeBSD
   should be able to work with blacklistd, too.

  31.6.1. Enabling Blacklistd

   The main configuration for blacklistd is stored in blacklistd.conf(5).
   Various command line options are also available to change blacklistd's
   run-time behavior. Persistent configuration across reboots should be
   stored in /etc/blacklistd.conf. To enable the daemon during system boot,
   add a blacklistd_enable line to /etc/rc.conf like this:

 # sysrc blacklistd_enable=yes

   To start the service manually, run this command:

 # service blacklistd start

  31.6.2. Creating a Blacklistd Ruleset

   Rules for blacklistd are configured in blacklistd.conf(5) with one entry
   per line. Each rule contains a tuple separated by spaces or tabs. Rules
   either belong to a local or a remote, which applies to the machine where
   blacklistd is running or an outside source, respectively.

    31.6.2.1. Local Rules

   An example blacklistd.conf entry for a local rule looks like this:

 [local]
 ssh             stream  *       *               *       3       24h

   All rules that follow the [local] section are treated as local rules
   (which is the default), applying to the local machine. When a [remote]
   section is encountered, all rules that follow it are handled as remote
   machine rules.

   Seven fields define a rule separated by either tabs or spaces. The first
   four fields identify the traffic that should be blacklisted. The three
   fields that follow define backlistd's behavior. Wildcards are denoted as
   asterisks (*), matching anything in this field. The first field defines
   the location. In local rules, these are the network ports. The syntax for
   the location field is as follows:

 [address|interface][/mask][:port]

   Adressses can be specified as IPv4 in numeric format or IPv6 in square
   brackets. An interface name like em0 can also be used.

   The socket type is defined by the second field. TCP sockets are of type
   stream, whereas UDP is denoted as dgram. The example above uses TCP, since
   SSH is using that protocol.

   A protocol can be used in the third field of a blacklistd rule. The
   following protocols can be used: tcp, udp, tcp6, udp6, or numeric. A
   wildcard, like in the example, is typically used to match all protocols
   unless there is a reason to distinguish traffic by a certain protocol.

   In the fourth field, the effective user or owner of the daemon process
   that is reporting the event is defined. The username or UID can be used
   here, as well as a wildcard (see example rule above).

   The packet filter rule name is declared by the fifth field, which starts
   the behavior part of the rule. By default, blacklistd puts all blocks
   under a pf anchor called blacklistd in pf.conf like this:

 anchor "blacklistd/*" in on $ext_if
 block in
 pass out

   For separate blacklists, an anchor name can be used in this field. In
   other cases, the wildcard will suffice. When a name starts with a hyphen
   (-) it means that an anchor with the default rule name prepended should be
   used. A modified example from the above using the hyphen would look like
   this:

 ssh             stream  *       *               -ssh       3       24h

   With such a rule, any new blacklist rules are added to an anchor called
   blacklistd-ssh.

   To block whole subnets for a single rule violation, a / in the rule name
   can be used. This causes the remaining portion of the name to be
   interpreted as the mask to be applied to the address specified in the
   rule. For example, this rule would block every address adjoining /24.

 22              stream  tcp       *               */24    3       24h

  Note:

   It is important to specify the proper protocol here. IPv4 and IPv6 treat
   /24 differently, that is the reason why * cannot be used in the third
   field for this rule.

   This rule defines that if any one host in that network is misbehaving,
   everything else on that network will be blocked, too.

   The sixth field, called nfail, sets the number of login failures required
   to blacklist the remote IP in question. When a wildcard is used at this
   position, it means that blocks will never happen. In the example rule
   above, a limit of three is defined meaning that after three attempts to
   log into SSH on one connection, the IP is blocked.

   The last field in a blacklistd rule definition specifies how long a host
   is blacklisted. The default unit is seconds, but suffixes like m, h, and d
   can also be specified for minutes, hours, and days, respectively.

   The example rule in its entirety means that after three times
   authenticating to SSH will result in a new PF block rule for that host.
   Rule matches are performed by first checking local rules one after
   another, from most specific to least specific. When a match occurs, the
   remote rules are applied and the name, nfail, and disable fields are
   changed by the remote rule that matched.

    31.6.2.2. Remote Rules

   Remote rules are used to specify how blacklistd changes its behavior
   depending on the remote host currently being evaluated. Each field in a
   remote rule is the same as in a local rule. The only difference is in the
   way blacklistd is using them. To explain it, this example rule is used:

 [remote]
 203.0.113.128/25 *      *       *               =/25    =       48h

   The address field can be an IP address (either v4 or v6), a port or both.
   This allows setting special rules for a specific remote address range like
   in this example. The fields for type, protocol and owner are identically
   interpreted as in the local rule.

   The name fields is different though: the equal sign (=) in a remote rule
   tells blacklistd to use the value from the matching local rule. It means
   that the firewall rule entry is taken and the /25 prefix (a netmask of
   255.255.255.128) is added. When a connection from that address range is
   blacklisted, the entire subnet is affected. A PF anchor name can also be
   used here, in which case blacklistd will add rules for this address block
   to the anchor of that name. The default table is used when a wildcard is
   specified.

   A custom number of failures in the nfail column can be defined for an
   address. This is useful for exceptions to a specific rule, to maybe allow
   someone a less strict application of rules or a bit more leniency in login
   tries. Blocking is disabled when an asterisk is used in this sixth field.

   Remote rules allow a stricter enforcement of limits on attempts to log in
   compared to attempts coming from a local network like an office.

  31.6.3. Blacklistd Client Configuration

   There are a few software packages in FreeBSD that can utilize blacklistd's
   functionality. The two most prominent ones are ftpd(8) and sshd(8) to
   block excessive connection attempts. To activate blacklistd in the SSH
   daemon, add the following line to /etc/ssh/sshd_config:

 UseBlacklist yes

   Restart sshd afterwards to make these changes take effect.

   Blacklisting for ftpd(8) is enabled using -B, either in /etc/inetd.conf or
   as a flag in /etc/rc.conf like this:

 ftpd_flags="-B"

   That is all that is needed to make these programs talk to blacklistd.

  31.6.4. Blacklistd Management

   Blacklistd provides the user with a management utility called
   blacklistctl(8). It displays blocked addresses and networks that are
   blacklisted by the rules defined in blacklistd.conf(5). To see the list of
   currently blocked hosts, use dump combined with -b like this.

 # blacklistctl dump -b
       address/ma:port id      nfail   last access
 213.0.123.128/25:22   OK      6/3     2019/06/08 14:30:19

   This example shows that there were 6 out of three permitted attempts on
   port 22 coming from the address range 213.0.123.128/25. There are more
   attempts listed than are allowed because SSH allows a client to try
   multiple logins on a single TCP connection. A connection that is currently
   going on is not stopped by blacklistd. The last connection attempt is
   listed in the last access column of the output.

   To see the remaining time that this host will be on the blacklist, add -r
   to the previous command.

 # blacklistctl dump -br
       address/ma:port id      nfail   remaining time
 213.0.123.128/25:22   OK      6/3     36s

   In this example, there are 36s seconds left until this host will not be
   blocked any more.

  31.6.5. Removing Hosts from the Block List

   Sometimes it is necessary to remove a host from the block list before the
   remaining time expires. Unfortunately, there is no functionality in
   blacklistd to do that. However, it is possible to remove the address from
   the PF table using pfctl. For each blocked port, there is a child anchor
   inside the blacklistd anchor defined in /etc/pf.conf. For example, if
   there is a child anchor for blocking port 22 it is called blacklistd/22.
   There is a table inside that child anchor that contains the blocked
   addresses. This table is called port followed by the port number. In this
   example, it would be called port22. With that information at hand, it is
   now possible to use pfctl(8) to display all addresses listed like this:

 # pfctl -a blacklistd/22 -t port22 -T show
 ...
 213.0.123.128/25
 ...

   After identifying the address to be unblocked from the list, the following
   command removes it from the list:

 # pfctl -a blacklistd/22 -t port22 -T delete 213.0.123.128/25

   The address is now removed from PF, but will still show up in the
   blacklistctl list, since it does not know about any changes made in PF.
   The entry in blacklistd's database will eventually expire and be removed
   from its output eventually. The entry will be added again if the host is
   matching one of the block rules in blacklistd again.

Chapter 32. Advanced Networking

   Table of Contents

   32.1. Synopsis

   32.2. Gateways and Routes

   32.3. Wireless Networking

   32.4. USB Tethering

   32.5. Bluetooth

   32.6. Bridging

   32.7. Link Aggregation and Failover

   32.8. Diskless Operation with PXE

   32.9. IPv6

   32.10. Common Address Redundancy Protocol (CARP)

   32.11. VLANs

32.1. Synopsis

   This chapter covers a number of advanced networking topics.

   After reading this chapter, you will know:

     * The basics of gateways and routes.

     * How to set up USB tethering.

     * How to set up IEEE(R) 802.11 and Bluetooth(R) devices.

     * How to make FreeBSD act as a bridge.

     * How to set up network PXE booting.

     * How to set up IPv6 on a FreeBSD machine.

     * How to enable and utilize the features of the Common Address
       Redundancy Protocol (CARP) in FreeBSD.

     * How to configure multiple VLANs on FreeBSD.

     * Configure bluetooth headset.

   Before reading this chapter, you should:

     * Understand the basics of the /etc/rc scripts.

     * Be familiar with basic network terminology.

     * Know how to configure and install a new FreeBSD kernel (Chapter 8,
       Configuring the FreeBSD Kernel).

     * Know how to install additional third-party software (Chapter 4,
       Installing Applications: Packages and Ports).

32.2. Gateways and Routes

   Contributed by Coranth Gryphon.

   Routing is the mechanism that allows a system to find the network path to
   another system. A route is a defined pair of addresses which represent the
   "destination" and a "gateway". The route indicates that when trying to get
   to the specified destination, send the packets through the specified
   gateway. There are three types of destinations: individual hosts, subnets,
   and "default". The "default route" is used if no other routes apply. There
   are also three types of gateways: individual hosts, interfaces, also
   called links, and Ethernet hardware (MAC) addresses. Known routes are
   stored in a routing table.

   This section provides an overview of routing basics. It then demonstrates
   how to configure a FreeBSD system as a router and offers some
   troubleshooting tips.

  32.2.1. Routing Basics

   To view the routing table of a FreeBSD system, use netstat(1):

 % netstat -r
 Routing tables

 Internet:
 Destination      Gateway            Flags     Refs     Use     Netif Expire
 default          outside-gw         UGS        37      418       em0
 localhost        localhost          UH          0      181       lo0
 test0            0:e0:b5:36:cf:4f   UHLW        5    63288       re0     77
 10.20.30.255     link#1             UHLW        1     2421
 example.com      link#1             UC          0        0
 host1            0:e0:a8:37:8:1e    UHLW        3     4601       lo0
 host2            0:e0:a8:37:8:1e    UHLW        0        5       lo0 =>
 host2.example.com link#1            UC          0        0
 224              link#1             UC          0        0

   The entries in this example are as follows:

   default

           The first route in this table specifies the default route. When
           the local system needs to make a connection to a remote host, it
           checks the routing table to determine if a known path exists. If
           the remote host matches an entry in the table, the system checks
           to see if it can connect using the interface specified in that
           entry.

           If the destination does not match an entry, or if all known paths
           fail, the system uses the entry for the default route. For hosts
           on a local area network, the Gateway field in the default route is
           set to the system which has a direct connection to the Internet.
           When reading this entry, verify that the Flags column indicates
           that the gateway is usable (UG).

           The default route for a machine which itself is functioning as the
           gateway to the outside world will be the gateway machine at the
           Internet Service Provider (ISP).

   localhost

           The second route is the localhost route. The interface specified
           in the Netif column for localhost is lo0, also known as the
           loopback device. This indicates that all traffic for this
           destination should be internal, rather than sending it out over
           the network.

   MAC address

           The addresses beginning with 0:e0: are MAC addresses. FreeBSD will
           automatically identify any hosts, test0 in the example, on the
           local Ethernet and add a route for that host over the Ethernet
           interface, re0. This type of route has a timeout, seen in the
           Expire column, which is used if the host does not respond in a
           specific amount of time. When this happens, the route to this host
           will be automatically deleted. These hosts are identified using
           the Routing Information Protocol (RIP), which calculates routes to
           local hosts based upon a shortest path determination.

   subnet

           FreeBSD will automatically add subnet routes for the local subnet.
           In this example, 10.20.30.255 is the broadcast address for the
           subnet 10.20.30 and example.com is the domain name associated with
           that subnet. The designation link#1 refers to the first Ethernet
           card in the machine.

           Local network hosts and local subnets have their routes
           automatically configured by a daemon called routed(8). If it is
           not running, only routes which are statically defined by the
           administrator will exist.

   host

           The host1 line refers to the host by its Ethernet address. Since
           it is the sending host, FreeBSD knows to use the loopback
           interface (lo0) rather than the Ethernet interface.

           The two host2 lines represent aliases which were created using
           ifconfig(8). The => symbol after the lo0 interface says that an
           alias has been set in addition to the loopback address. Such
           routes only show up on the host that supports the alias and all
           other hosts on the local network will have a link#1 line for such
           routes.

   224

           The final line (destination subnet 224) deals with multicasting.

   Various attributes of each route can be seen in the Flags column.
   Table 32.1, "Commonly Seen Routing Table Flags" summarizes some of these
   flags and their meanings:

   Table 32.1. Commonly Seen Routing Table Flags

   Command                              Purpose                               
   U       The route is active (up).                                          
   H       The route destination is a single host.                            
   G       Send anything for this destination on to this gateway, which will  
           figure out from there where to send it.                            
   S       This route was statically configured.                              
   C       Clones a new route based upon this route for machines to connect   
           to. This type of route is normally used for local networks.        
   W       The route was auto-configured based upon a local area network      
           (clone) route.                                                     
   L       Route involves references to Ethernet (link) hardware.             

   On a FreeBSD system, the default route can defined in /etc/rc.conf by
   specifying the IP address of the default gateway:

 defaultrouter="10.20.30.1"

   It is also possible to manually add the route using route:

 # route add default 10.20.30.1

   Note that manually added routes will not survive a reboot. For more
   information on manual manipulation of network routing tables, refer to
   route(8).

  32.2.2. Configuring a Router with Static Routes

   Contributed by Al Hoang.

   A FreeBSD system can be configured as the default gateway, or router, for
   a network if it is a dual-homed system. A dual-homed system is a host
   which resides on at least two different networks. Typically, each network
   is connected to a separate network interface, though IP aliasing can be
   used to bind multiple addresses, each on a different subnet, to one
   physical interface.

   In order for the system to forward packets between interfaces, FreeBSD
   must be configured as a router. Internet standards and good engineering
   practice prevent the FreeBSD Project from enabling this feature by
   default, but it can be configured to start at boot by adding this line to
   /etc/rc.conf:

 gateway_enable="YES"          # Set to YES if this host will be a gateway

   To enable routing now, set the sysctl(8) variable net.inet.ip.forwarding
   to 1. To stop routing, reset this variable to 0.

   The routing table of a router needs additional routes so it knows how to
   reach other networks. Routes can be either added manually using static
   routes or routes can be automatically learned using a routing protocol.
   Static routes are appropriate for small networks and this section
   describes how to add a static routing entry for a small network.

  Note:

   For large networks, static routes quickly become unscalable. FreeBSD comes
   with the standard BSD routing daemon routed(8), which provides the routing
   protocols RIP, versions 1 and 2, and IRDP. Support for the BGP and OSPF
   routing protocols can be installed using the net/zebra package or port.

   Consider the following network:

   In this scenario, RouterA is a FreeBSD machine that is acting as a router
   to the rest of the Internet. It has a default route set to 10.0.0.1 which
   allows it to connect with the outside world. RouterB is already configured
   to use 192.168.1.1 as its default gateway.

   Before adding any static routes, the routing table on RouterA looks like
   this:

 % netstat -nr
 Routing tables

 Internet:
 Destination        Gateway            Flags    Refs      Use  Netif  Expire
 default            10.0.0.1           UGS         0    49378    xl0
 127.0.0.1          127.0.0.1          UH          0        6    lo0
 10.0.0.0/24        link#1             UC          0        0    xl0
 192.168.1.0/24     link#2             UC          0        0    xl1

   With the current routing table, RouterA does not have a route to the
   192.168.2.0/24 network. The following command adds the Internal Net 2
   network to RouterA's routing table using 192.168.1.2 as the next hop:

 # route add -net 192.168.2.0/24 192.168.1.2

   Now, RouterA can reach any host on the 192.168.2.0/24 network. However,
   the routing information will not persist if the FreeBSD system reboots. If
   a static route needs to be persistent, add it to /etc/rc.conf:

 # Add Internal Net 2 as a persistent static route
 static_routes="internalnet2"
 route_internalnet2="-net 192.168.2.0/24 192.168.1.2"

   The static_routes configuration variable is a list of strings separated by
   a space, where each string references a route name. The variable
   route_internalnet2 contains the static route for that route name.

   Using more than one string in static_routes creates multiple static
   routes. The following shows an example of adding static routes for the
   192.168.0.0/24 and 192.168.1.0/24 networks:

 static_routes="net1 net2"
 route_net1="-net 192.168.0.0/24 192.168.0.1"
 route_net2="-net 192.168.1.0/24 192.168.1.1"

  32.2.3. Troubleshooting

   When an address space is assigned to a network, the service provider
   configures their routing tables so that all traffic for the network will
   be sent to the link for the site. But how do external sites know to send
   their packets to the network's ISP?

   There is a system that keeps track of all assigned address spaces and
   defines their point of connection to the Internet backbone, or the main
   trunk lines that carry Internet traffic across the country and around the
   world. Each backbone machine has a copy of a master set of tables, which
   direct traffic for a particular network to a specific backbone carrier,
   and from there down the chain of service providers until it reaches a
   particular network.

   It is the task of the service provider to advertise to the backbone sites
   that they are the point of connection, and thus the path inward, for a
   site. This is known as route propagation.

   Sometimes, there is a problem with route propagation and some sites are
   unable to connect. Perhaps the most useful command for trying to figure
   out where routing is breaking down is traceroute. It is useful when ping
   fails.

   When using traceroute, include the address of the remote host to connect
   to. The output will show the gateway hosts along the path of the attempt,
   eventually either reaching the target host, or terminating because of a
   lack of connection. For more information, refer to traceroute(8).

  32.2.4. Multicast Considerations

   FreeBSD natively supports both multicast applications and multicast
   routing. Multicast applications do not require any special configuration
   in order to run on FreeBSD. Support for multicast routing requires that
   the following option be compiled into a custom kernel:

 options MROUTING

   The multicast routing daemon, mrouted can be installed using the
   net/mrouted package or port. This daemon implements the DVMRP multicast
   routing protocol and is configured by editing /usr/local/etc/mrouted.conf
   in order to set up the tunnels and DVMRP. The installation of mrouted also
   installs map-mbone and mrinfo, as well as their associated man pages.
   Refer to these for configuration examples.

  Note:

   DVMRP has largely been replaced by the PIM protocol in many multicast
   installations. Refer to pim(4) for more information.

32.3. Wireless Networking

   Loader, Marc Fonvieille and Murray Stokely.

  32.3.1. Wireless Networking Basics

   Most wireless networks are based on the IEEE(R) 802.11 standards. A basic
   wireless network consists of multiple stations communicating with radios
   that broadcast in either the 2.4GHz or 5GHz band, though this varies
   according to the locale and is also changing to enable communication in
   the 2.3GHz and 4.9GHz ranges.

   802.11 networks are organized in two ways. In infrastructure mode, one
   station acts as a master with all the other stations associating to it,
   the network is known as a BSS, and the master station is termed an access
   point (AP). In a BSS, all communication passes through the AP; even when
   one station wants to communicate with another wireless station, messages
   must go through the AP. In the second form of network, there is no master
   and stations communicate directly. This form of network is termed an IBSS
   and is commonly known as an ad-hoc network.

   802.11 networks were first deployed in the 2.4GHz band using protocols
   defined by the IEEE(R) 802.11 and 802.11b standard. These specifications
   include the operating frequencies and the MAC layer characteristics,
   including framing and transmission rates, as communication can occur at
   various rates. Later, the 802.11a standard defined operation in the 5GHz
   band, including different signaling mechanisms and higher transmission
   rates. Still later, the 802.11g standard defined the use of 802.11a
   signaling and transmission mechanisms in the 2.4GHz band in such a way as
   to be backwards compatible with 802.11b networks.

   Separate from the underlying transmission techniques, 802.11 networks have
   a variety of security mechanisms. The original 802.11 specifications
   defined a simple security protocol called WEP. This protocol uses a fixed
   pre-shared key and the RC4 cryptographic cipher to encode data transmitted
   on a network. Stations must all agree on the fixed key in order to
   communicate. This scheme was shown to be easily broken and is now rarely
   used except to discourage transient users from joining networks. Current
   security practice is given by the IEEE(R) 802.11i specification that
   defines new cryptographic ciphers and an additional protocol to
   authenticate stations to an access point and exchange keys for data
   communication. Cryptographic keys are periodically refreshed and there are
   mechanisms for detecting and countering intrusion attempts. Another
   security protocol specification commonly used in wireless networks is
   termed WPA, which was a precursor to 802.11i. WPA specifies a subset of
   the requirements found in 802.11i and is designed for implementation on
   legacy hardware. Specifically, WPA requires only the TKIP cipher that is
   derived from the original WEP cipher. 802.11i permits use of TKIP but also
   requires support for a stronger cipher, AES-CCM, for encrypting data. The
   AES cipher was not required in WPA because it was deemed too
   computationally costly to be implemented on legacy hardware.

   The other standard to be aware of is 802.11e. It defines protocols for
   deploying multimedia applications, such as streaming video and voice over
   IP (VoIP), in an 802.11 network. Like 802.11i, 802.11e also has a
   precursor specification termed WME (later renamed WMM) that has been
   defined by an industry group as a subset of 802.11e that can be deployed
   now to enable multimedia applications while waiting for the final
   ratification of 802.11e. The most important thing to know about 802.11e
   and WME/WMM is that it enables prioritized traffic over a wireless network
   through Quality of Service (QoS) protocols and enhanced media access
   protocols. Proper implementation of these protocols enables high speed
   bursting of data and prioritized traffic flow.

   FreeBSD supports networks that operate using 802.11a, 802.11b, and
   802.11g. The WPA and 802.11i security protocols are likewise supported (in
   conjunction with any of 11a, 11b, and 11g) and QoS and traffic
   prioritization required by the WME/WMM protocols are supported for a
   limited set of wireless devices.

  32.3.2. Quick Start

   Connecting a computer to an existing wireless network is a very common
   situation. This procedure shows the steps required.

    1. Obtain the SSID (Service Set Identifier) and PSK (Pre-Shared Key) for
       the wireless network from the network administrator.

    2. Identify the wireless adapter. The FreeBSD GENERIC kernel includes
       drivers for many common wireless adapters. If the wireless adapter is
       one of those models, it will be shown in the output from ifconfig(8):

 % ifconfig | grep -B3 -i wireless

       On FreeBSD 11 or higher, use this command instead:

 % sysctl net.wlan.devices

       If a wireless adapter is not listed, an additional kernel module might
       be required, or it might be a model not supported by FreeBSD.

       This example shows the Atheros ath0 wireless adapter.

    3. Add an entry for this network to /etc/wpa_supplicant.conf. If the file
       does not exist, create it. Replace myssid and mypsk with the SSID and
       PSK provided by the network administrator.

 network={
         ssid="myssid"
         psk="mypsk"
 }

    4. Add entries to /etc/rc.conf to configure the network on startup:

 wlans_ath0="wlan0"
 ifconfig_wlan0="WPA SYNCDHCP"

    5. Restart the computer, or restart the network service to connect to the
       network:

 # service netif restart

  32.3.3. Basic Setup

    32.3.3.1. Kernel Configuration

   To use wireless networking, a wireless networking card is needed and the
   kernel needs to be configured with the appropriate wireless networking
   support. The kernel is separated into multiple modules so that only the
   required support needs to be configured.

   The most commonly used wireless devices are those that use parts made by
   Atheros. These devices are supported by ath(4) and require the following
   line to be added to /boot/loader.conf:

 if_ath_load="YES"

   The Atheros driver is split up into three separate pieces: the driver
   (ath(4)), the hardware support layer that handles chip-specific functions
   (ath_hal(4)), and an algorithm for selecting the rate for transmitting
   frames. When this support is loaded as kernel modules, any dependencies
   are automatically handled. To load support for a different type of
   wireless device, specify the module for that device. This example is for
   devices based on the Intersil Prism parts (wi(4)) driver:

 if_wi_load="YES"

  Note:

   The examples in this section use an ath(4) device and the device name in
   the examples must be changed according to the configuration. A list of
   available wireless drivers and supported adapters can be found in the
   FreeBSD Hardware Notes, available on the Release Information page of the
   FreeBSD website. If a native FreeBSD driver for the wireless device does
   not exist, it may be possible to use the Windows(R) driver with the help
   of the NDIS driver wrapper.

   In addition, the modules that implement cryptographic support for the
   security protocols to use must be loaded. These are intended to be
   dynamically loaded on demand by the wlan(4) module, but for now they must
   be manually configured. The following modules are available: wlan_wep(4),
   wlan_ccmp(4), and wlan_tkip(4). The wlan_ccmp(4) and wlan_tkip(4) drivers
   are only needed when using the WPA or 802.11i security protocols. If the
   network does not use encryption, wlan_wep(4) support is not needed. To
   load these modules at boot time, add the following lines to
   /boot/loader.conf:

 wlan_wep_load="YES"
 wlan_ccmp_load="YES"
 wlan_tkip_load="YES"

   Once this information has been added to /boot/loader.conf, reboot the
   FreeBSD box. Alternately, load the modules by hand using kldload(8).

  Note:

   For users who do not want to use modules, it is possible to compile these
   drivers into the kernel by adding the following lines to a custom kernel
   configuration file:

 device wlan              # 802.11 support
 device wlan_wep          # 802.11 WEP support
 device wlan_ccmp         # 802.11 CCMP support
 device wlan_tkip         # 802.11 TKIP support
 device wlan_amrr         # AMRR transmit rate control algorithm
 device ath               # Atheros pci/cardbus NIC's
 device ath_hal           # pci/cardbus chip support
 options AH_SUPPORT_AR5416 # enable AR5416 tx/rx descriptors
 device ath_rate_sample   # SampleRate tx rate control for ath

   With this information in the kernel configuration file, recompile the
   kernel and reboot the FreeBSD machine.

   Information about the wireless device should appear in the boot messages,
   like this:

 ath0: <Atheros 5212> mem 0x88000000-0x8800ffff irq 11 at device 0.0 on cardbus1
 ath0: [ITHREAD]
 ath0: AR2413 mac 7.9 RF2413 phy 4.5

    32.3.3.2. Setting the Correct Region

   Since the regulatory situation is different in various parts of the world,
   it is necessary to correctly set the domains that apply to your location
   to have the correct information about what channels can be used.

   The available region definitions can be found in /etc/regdomain.xml. To
   set the data at runtime, use ifconfig:

 # ifconfig wlan0 regdomain ETSI country AT

   To persist the settings, add it to /etc/rc.conf:

 # sysrc create_args_wlan0="country AT regdomain ETSI"

  32.3.4. Infrastructure Mode

   Infrastructure (BSS) mode is the mode that is typically used. In this
   mode, a number of wireless access points are connected to a wired network.
   Each wireless network has its own name, called the SSID. Wireless clients
   connect to the wireless access points.

    32.3.4.1. FreeBSD Clients

      32.3.4.1.1. How to Find Access Points

   To scan for available networks, use ifconfig(8). This request may take a
   few moments to complete as it requires the system to switch to each
   available wireless frequency and probe for available access points. Only
   the superuser can initiate a scan:

 # ifconfig wlan0 create wlandev ath0
 # ifconfig wlan0 up scan
 SSID/MESH ID    BSSID              CHAN RATE   S:N     INT CAPS
 dlinkap         00:13:46:49:41:76   11   54M -90:96   100 EPS  WPA WME
 freebsdap       00:11:95:c3:0d:ac    1   54M -83:96   100 EPS  WPA

  Note:

   The interface must be up before it can scan. Subsequent scan requests do
   not require the interface to be marked as up again.

   The output of a scan request lists each BSS/IBSS network found. Besides
   listing the name of the network, the SSID, the output also shows the
   BSSID, which is the MAC address of the access point. The CAPS field
   identifies the type of each network and the capabilities of the stations
   operating there:

   Table 32.2. Station Capability Codes

   Capability Code                          Meaning                           
                   Extended Service Set (ESS). Indicates that the station is  
   E               part of an infrastructure network rather than an           
                   IBSS/ad-hoc network.                                       
   I               IBSS/ad-hoc network. Indicates that the station is part of 
                   an ad-hoc network rather than an ESS network.              
                   Privacy. Encryption is required for all data frames        
   P               exchanged within the BSS using cryptographic means such as 
                   WEP, TKIP or AES-CCMP.                                     
                   Short Preamble. Indicates that the network is using short  
   S               preambles, defined in 802.11b High Rate/DSSS PHY, and      
                   utilizes a 56 bit sync field rather than the 128 bit field 
                   used in long preamble mode.                                
                   Short slot time. Indicates that the 802.11g network is     
   s               using a short slot time because there are no legacy        
                   (802.11b) stations present.                                

   One can also display the current list of known networks with:

 # ifconfig wlan0 list scan

   This information may be updated automatically by the adapter or manually
   with a scan request. Old data is automatically removed from the cache, so
   over time this list may shrink unless more scans are done.

      32.3.4.1.2. Basic Settings

   This section provides a simple example of how to make the wireless network
   adapter work in FreeBSD without encryption. Once familiar with these
   concepts, it is strongly recommend to use WPA to set up the wireless
   network.

   There are three basic steps to configure a wireless network: select an
   access point, authenticate the station, and configure an IP address. The
   following sections discuss each step.

        32.3.4.1.2.1. Selecting an Access Point

   Most of the time, it is sufficient to let the system choose an access
   point using the builtin heuristics. This is the default behavior when an
   interface is marked as up or it is listed in /etc/rc.conf:

 wlans_ath0="wlan0"
 ifconfig_wlan0="DHCP"

   If there are multiple access points, a specific one can be selected by its
   SSID:

 wlans_ath0="wlan0"
 ifconfig_wlan0="ssid your_ssid_here DHCP"

   In an environment where there are multiple access points with the same
   SSID, which is often done to simplify roaming, it may be necessary to
   associate to one specific device. In this case, the BSSID of the access
   point can be specified, with or without the SSID:

 wlans_ath0="wlan0"
 ifconfig_wlan0="ssid your_ssid_here bssid xx:xx:xx:xx:xx:xx DHCP"

   There are other ways to constrain the choice of an access point, such as
   limiting the set of frequencies the system will scan on. This may be
   useful for a multi-band wireless card as scanning all the possible
   channels can be time-consuming. To limit operation to a specific band, use
   the mode parameter:

 wlans_ath0="wlan0"
 ifconfig_wlan0="mode 11g ssid your_ssid_here DHCP"

   This example will force the card to operate in 802.11g, which is defined
   only for 2.4GHz frequencies so any 5GHz channels will not be considered.
   This can also be achieved with the channel parameter, which locks
   operation to one specific frequency, and the chanlist parameter, to
   specify a list of channels for scanning. More information about these
   parameters can be found in ifconfig(8).

        32.3.4.1.2.2. Authentication

   Once an access point is selected, the station needs to authenticate before
   it can pass data. Authentication can happen in several ways. The most
   common scheme, open authentication, allows any station to join the network
   and communicate. This is the authentication to use for test purposes the
   first time a wireless network is setup. Other schemes require
   cryptographic handshakes to be completed before data traffic can flow,
   either using pre-shared keys or secrets, or more complex schemes that
   involve backend services such as RADIUS. Open authentication is the
   default setting. The next most common setup is WPA-PSK, also known as WPA
   Personal, which is described in Section 32.3.4.1.3.1, "WPA-PSK".

  Note:

   If using an Apple(R) AirPort(R) Extreme base station for an access point,
   shared-key authentication together with a WEP key needs to be configured.
   This can be configured in /etc/rc.conf or by using wpa_supplicant(8). For
   a single AirPort(R) base station, access can be configured with:

 wlans_ath0="wlan0"
 ifconfig_wlan0="authmode shared wepmode on weptxkey 1 wepkey 01234567 DHCP"

   In general, shared key authentication should be avoided because it uses
   the WEP key material in a highly-constrained manner, making it even easier
   to crack the key. If WEP must be used for compatibility with legacy
   devices, it is better to use WEP with open authentication. More
   information regarding WEP can be found in Section 32.3.4.1.4, "WEP".

        32.3.4.1.2.3. Getting an IP Address with DHCP

   Once an access point is selected and the authentication parameters are
   set, an IP address must be obtained in order to communicate. Most of the
   time, the IP address is obtained via DHCP. To achieve that, edit
   /etc/rc.conf and add DHCP to the configuration for the device:

 wlans_ath0="wlan0"
 ifconfig_wlan0="DHCP"

   The wireless interface is now ready to bring up:

 # service netif start

   Once the interface is running, use ifconfig(8) to see the status of the
   interface ath0:

 # ifconfig wlan0
 wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
         ether 00:11:95:d5:43:62
         inet 192.168.1.100 netmask 0xffffff00 broadcast 192.168.1.255
         media: IEEE 802.11 Wireless Ethernet OFDM/54Mbps mode 11g
         status: associated
         ssid dlinkap channel 11 (2462 Mhz 11g) bssid 00:13:46:49:41:76
         country US ecm authmode OPEN privacy OFF txpower 21.5 bmiss 7
         scanvalid 60 bgscan bgscanintvl 300 bgscanidle 250 roam:rssi 7
         roam:rate 5 protmode CTS wme burst

   The status: associated line means that it is connected to the wireless
   network. The bssid 00:13:46:49:41:76 is the MAC address of the access
   point and authmode OPEN indicates that the communication is not encrypted.

        32.3.4.1.2.4. Static IP Address

   If an IP address cannot be obtained from a DHCP server, set a fixed IP
   address. Replace the DHCP keyword shown above with the address
   information. Be sure to retain any other parameters for selecting the
   access point:

 wlans_ath0="wlan0"
 ifconfig_wlan0="inet 192.168.1.100 netmask 255.255.255.0 ssid your_ssid_here"

      32.3.4.1.3. WPA

   Wi-Fi Protected Access (WPA) is a security protocol used together with
   802.11 networks to address the lack of proper authentication and the
   weakness of WEP. WPA leverages the 802.1X authentication protocol and uses
   one of several ciphers instead of WEP for data integrity. The only cipher
   required by WPA is the Temporary Key Integrity Protocol (TKIP). TKIP is a
   cipher that extends the basic RC4 cipher used by WEP by adding integrity
   checking, tamper detection, and measures for responding to detected
   intrusions. TKIP is designed to work on legacy hardware with only software
   modification. It represents a compromise that improves security but is
   still not entirely immune to attack. WPA also specifies the AES-CCMP
   cipher as an alternative to TKIP, and that is preferred when possible. For
   this specification, the term WPA2 or RSN is commonly used.

   WPA defines authentication and encryption protocols. Authentication is
   most commonly done using one of two techniques: by 802.1X and a backend
   authentication service such as RADIUS, or by a minimal handshake between
   the station and the access point using a pre-shared secret. The former is
   commonly termed WPA Enterprise and the latter is known as WPA Personal.
   Since most people will not set up a RADIUS backend server for their
   wireless network, WPA-PSK is by far the most commonly encountered
   configuration for WPA.

   The control of the wireless connection and the key negotiation or
   authentication with a server is done using wpa_supplicant(8). This program
   requires a configuration file, /etc/wpa_supplicant.conf, to run. More
   information regarding this file can be found in wpa_supplicant.conf(5).

        32.3.4.1.3.1. WPA-PSK

   WPA-PSK, also known as WPA Personal, is based on a pre-shared key (PSK)
   which is generated from a given password and used as the master key in the
   wireless network. This means every wireless user will share the same key.
   WPA-PSK is intended for small networks where the use of an authentication
   server is not possible or desired.

  Warning:

   Always use strong passwords that are sufficiently long and made from a
   rich alphabet so that they will not be easily guessed or attacked.

   The first step is the configuration of /etc/wpa_supplicant.conf with the
   SSID and the pre-shared key of the network:

 network={
   ssid="freebsdap"
   psk="freebsdmall"
 }

   Then, in /etc/rc.conf, indicate that the wireless device configuration
   will be done with WPA and the IP address will be obtained with DHCP:

 wlans_ath0="wlan0"
 ifconfig_wlan0="WPA DHCP"

   Then, bring up the interface:

 # service netif start
 Starting wpa_supplicant.
 DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 5
 DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 6
 DHCPOFFER from 192.168.0.1
 DHCPREQUEST on wlan0 to 255.255.255.255 port 67
 DHCPACK from 192.168.0.1
 bound to 192.168.0.254 -- renewal in 300 seconds.
 wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
       ether 00:11:95:d5:43:62
       inet 192.168.0.254 netmask 0xffffff00 broadcast 192.168.0.255
       media: IEEE 802.11 Wireless Ethernet OFDM/36Mbps mode 11g
       status: associated
       ssid freebsdap channel 1 (2412 Mhz 11g) bssid 00:11:95:c3:0d:ac
       country US ecm authmode WPA2/802.11i privacy ON deftxkey UNDEF
       AES-CCM 3:128-bit txpower 21.5 bmiss 7 scanvalid 450 bgscan
       bgscanintvl 300 bgscanidle 250 roam:rssi 7 roam:rate 5 protmode CTS
       wme burst roaming MANUAL

   Or, try to configure the interface manually using the information in
   /etc/wpa_supplicant.conf:

 # wpa_supplicant -i wlan0 -c /etc/wpa_supplicant.conf
 Trying to associate with 00:11:95:c3:0d:ac (SSID='freebsdap' freq=2412 MHz)
 Associated with 00:11:95:c3:0d:ac
 WPA: Key negotiation completed with 00:11:95:c3:0d:ac [PTK=CCMP GTK=CCMP]
 CTRL-EVENT-CONNECTED - Connection to 00:11:95:c3:0d:ac completed (auth) [id=0 id_str=]

   The next operation is to launch dhclient(8) to get the IP address from the
   DHCP server:

 # dhclient wlan0
 DHCPREQUEST on wlan0 to 255.255.255.255 port 67
 DHCPACK from 192.168.0.1
 bound to 192.168.0.254 -- renewal in 300 seconds.
 # ifconfig wlan0
 wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
       ether 00:11:95:d5:43:62
       inet 192.168.0.254 netmask 0xffffff00 broadcast 192.168.0.255
       media: IEEE 802.11 Wireless Ethernet OFDM/36Mbps mode 11g
       status: associated
       ssid freebsdap channel 1 (2412 Mhz 11g) bssid 00:11:95:c3:0d:ac
       country US ecm authmode WPA2/802.11i privacy ON deftxkey UNDEF
       AES-CCM 3:128-bit txpower 21.5 bmiss 7 scanvalid 450 bgscan
       bgscanintvl 300 bgscanidle 250 roam:rssi 7 roam:rate 5 protmode CTS
       wme burst roaming MANUAL

  Note:

   If /etc/rc.conf has an ifconfig_wlan0="DHCP" entry, dhclient(8) will be
   launched automatically after wpa_supplicant(8) associates with the access
   point.

   If DHCP is not possible or desired, set a static IP address after
   wpa_supplicant(8) has authenticated the station:

 # ifconfig wlan0 inet 192.168.0.100 netmask 255.255.255.0
 # ifconfig wlan0
 wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
       ether 00:11:95:d5:43:62
       inet 192.168.0.100 netmask 0xffffff00 broadcast 192.168.0.255
       media: IEEE 802.11 Wireless Ethernet OFDM/36Mbps mode 11g
       status: associated
       ssid freebsdap channel 1 (2412 Mhz 11g) bssid 00:11:95:c3:0d:ac
       country US ecm authmode WPA2/802.11i privacy ON deftxkey UNDEF
       AES-CCM 3:128-bit txpower 21.5 bmiss 7 scanvalid 450 bgscan
       bgscanintvl 300 bgscanidle 250 roam:rssi 7 roam:rate 5 protmode CTS
       wme burst roaming MANUAL

   When DHCP is not used, the default gateway and the nameserver also have to
   be manually set:

 # route add default your_default_router
 # echo "nameserver your_DNS_server" >> /etc/resolv.conf

        32.3.4.1.3.2. WPA with EAP-TLS

   The second way to use WPA is with an 802.1X backend authentication server.
   In this case, WPA is called WPA Enterprise to differentiate it from the
   less secure WPA Personal. Authentication in WPA Enterprise is based on the
   Extensible Authentication Protocol (EAP).

   EAP does not come with an encryption method. Instead, EAP is embedded
   inside an encrypted tunnel. There are many EAP authentication methods, but
   EAP-TLS, EAP-TTLS, and EAP-PEAP are the most common.

   EAP with Transport Layer Security (EAP-TLS) is a well-supported wireless
   authentication protocol since it was the first EAP method to be certified
   by the Wi-Fi Alliance. EAP-TLS requires three certificates to run: the
   certificate of the Certificate Authority (CA) installed on all machines,
   the server certificate for the authentication server, and one client
   certificate for each wireless client. In this EAP method, both the
   authentication server and wireless client authenticate each other by
   presenting their respective certificates, and then verify that these
   certificates were signed by the organization's CA.

   As previously, the configuration is done via /etc/wpa_supplicant.conf:

 network={
   ssid="freebsdap" 1
   proto=RSN  2
   key_mgmt=WPA-EAP 3
   eap=TLS 4
   identity="loader" 5
   ca_cert="/etc/certs/cacert.pem" 6
   client_cert="/etc/certs/clientcert.pem" 7
   private_key="/etc/certs/clientkey.pem" 8
   private_key_passwd="freebsdmallclient" 9
 }

   1 This field indicates the network name (SSID).                            
   2 This example uses the RSN IEEE(R) 802.11i protocol, also known as WPA2.  
   3 The key_mgmt line refers to the key management protocol to use. In this  
     example, it is WPA using EAP authentication.                             
   4 This field indicates the EAP method for the connection.                  
   5 The identity field contains the identity string for EAP.                 
   6 The ca_cert field indicates the pathname of the CA certificate file.     
     This file is needed to verify the server certificate.                    
   7 The client_cert line gives the pathname to the client certificate file.  
     This certificate is unique to each wireless client of the network.       
   8 The private_key field is the pathname to the client certificate private  
     key file.                                                                
   9 The private_key_passwd field contains the passphrase for the private     
     key.                                                                     

   Then, add the following lines to /etc/rc.conf:

 wlans_ath0="wlan0"
 ifconfig_wlan0="WPA DHCP"

   The next step is to bring up the interface:

 # service netif start
 Starting wpa_supplicant.
 DHCPREQUEST on wlan0 to 255.255.255.255 port 67 interval 7
 DHCPREQUEST on wlan0 to 255.255.255.255 port 67 interval 15
 DHCPACK from 192.168.0.20
 bound to 192.168.0.254 -- renewal in 300 seconds.
 wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
       ether 00:11:95:d5:43:62
       inet 192.168.0.254 netmask 0xffffff00 broadcast 192.168.0.255
       media: IEEE 802.11 Wireless Ethernet DS/11Mbps mode 11g
       status: associated
       ssid freebsdap channel 1 (2412 Mhz 11g) bssid 00:11:95:c3:0d:ac
       country US ecm authmode WPA2/802.11i privacy ON deftxkey UNDEF
       AES-CCM 3:128-bit txpower 21.5 bmiss 7 scanvalid 450 bgscan
       bgscanintvl 300 bgscanidle 250 roam:rssi 7 roam:rate 5 protmode CTS
       wme burst roaming MANUAL

   It is also possible to bring up the interface manually using
   wpa_supplicant(8) and ifconfig(8).

        32.3.4.1.3.3. WPA with EAP-TTLS

   With EAP-TLS, both the authentication server and the client need a
   certificate. With EAP-TTLS, a client certificate is optional. This method
   is similar to a web server which creates a secure SSL tunnel even if
   visitors do not have client-side certificates. EAP-TTLS uses an encrypted
   TLS tunnel for safe transport of the authentication data.

   The required configuration can be added to /etc/wpa_supplicant.conf:

 network={
   ssid="freebsdap"
   proto=RSN
   key_mgmt=WPA-EAP
   eap=TTLS 1
   identity="test" 2
   password="test" 3
   ca_cert="/etc/certs/cacert.pem" 4
   phase2="auth=MD5" 5
 }

   1 This field specifies the EAP method for the connection.                  
   2 The identity field contains the identity string for EAP authentication   
     inside the encrypted TLS tunnel.                                         
   3 The password field contains the passphrase for the EAP authentication.   
   4 The ca_cert field indicates the pathname of the CA certificate file.     
     This file is needed to verify the server certificate.                    
   5 This field specifies the authentication method used in the encrypted TLS 
     tunnel. In this example, EAP with MD5-Challenge is used. The "inner      
     authentication" phase is often called "phase2".                          

   Next, add the following lines to /etc/rc.conf:

 wlans_ath0="wlan0"
 ifconfig_wlan0="WPA DHCP"

   The next step is to bring up the interface:

 # service netif start
 Starting wpa_supplicant.
 DHCPREQUEST on wlan0 to 255.255.255.255 port 67 interval 7
 DHCPREQUEST on wlan0 to 255.255.255.255 port 67 interval 15
 DHCPREQUEST on wlan0 to 255.255.255.255 port 67 interval 21
 DHCPACK from 192.168.0.20
 bound to 192.168.0.254 -- renewal in 300 seconds.
 wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
       ether 00:11:95:d5:43:62
       inet 192.168.0.254 netmask 0xffffff00 broadcast 192.168.0.255
       media: IEEE 802.11 Wireless Ethernet DS/11Mbps mode 11g
       status: associated
       ssid freebsdap channel 1 (2412 Mhz 11g) bssid 00:11:95:c3:0d:ac
       country US ecm authmode WPA2/802.11i privacy ON deftxkey UNDEF
       AES-CCM 3:128-bit txpower 21.5 bmiss 7 scanvalid 450 bgscan
       bgscanintvl 300 bgscanidle 250 roam:rssi 7 roam:rate 5 protmode CTS
       wme burst roaming MANUAL

        32.3.4.1.3.4. WPA with EAP-PEAP

  Note:

   PEAPv0/EAP-MSCHAPv2 is the most common PEAP method. In this chapter, the
   term PEAP is used to refer to that method.

   Protected EAP (PEAP) is designed as an alternative to EAP-TTLS and is the
   most used EAP standard after EAP-TLS. In a network with mixed operating
   systems, PEAP should be the most supported standard after EAP-TLS.

   PEAP is similar to EAP-TTLS as it uses a server-side certificate to
   authenticate clients by creating an encrypted TLS tunnel between the
   client and the authentication server, which protects the ensuing exchange
   of authentication information. PEAP authentication differs from EAP-TTLS
   as it broadcasts the username in the clear and only the password is sent
   in the encrypted TLS tunnel. EAP-TTLS will use the TLS tunnel for both the
   username and password.

   Add the following lines to /etc/wpa_supplicant.conf to configure the
   EAP-PEAP related settings:

 network={
   ssid="freebsdap"
   proto=RSN
   key_mgmt=WPA-EAP
   eap=PEAP 1
   identity="test" 2
   password="test" 3
   ca_cert="/etc/certs/cacert.pem" 4
   phase1="peaplabel=0" 5
   phase2="auth=MSCHAPV2" 6
 }

   1 This field specifies the EAP method for the connection.                  
   2 The identity field contains the identity string for EAP authentication   
     inside the encrypted TLS tunnel.                                         
   3 The password field contains the passphrase for the EAP authentication.   
   4 The ca_cert field indicates the pathname of the CA certificate file.     
     This file is needed to verify the server certificate.                    
   5 This field contains the parameters for the first phase of                
     authentication, the TLS tunnel. According to the authentication server   
     used, specify a specific label for authentication. Most of the time, the 
     label will be "client EAP encryption" which is set by using peaplabel=0. 
     More information can be found in wpa_supplicant.conf(5).                 
   6 This field specifies the authentication protocol used in the encrypted   
     TLS tunnel. In the case of PEAP, it is auth=MSCHAPV2.                    

   Add the following to /etc/rc.conf:

 wlans_ath0="wlan0"
 ifconfig_wlan0="WPA DHCP"

   Then, bring up the interface:

 # service netif start
 Starting wpa_supplicant.
 DHCPREQUEST on wlan0 to 255.255.255.255 port 67 interval 7
 DHCPREQUEST on wlan0 to 255.255.255.255 port 67 interval 15
 DHCPREQUEST on wlan0 to 255.255.255.255 port 67 interval 21
 DHCPACK from 192.168.0.20
 bound to 192.168.0.254 -- renewal in 300 seconds.
 wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
       ether 00:11:95:d5:43:62
       inet 192.168.0.254 netmask 0xffffff00 broadcast 192.168.0.255
       media: IEEE 802.11 Wireless Ethernet DS/11Mbps mode 11g
       status: associated
       ssid freebsdap channel 1 (2412 Mhz 11g) bssid 00:11:95:c3:0d:ac
       country US ecm authmode WPA2/802.11i privacy ON deftxkey UNDEF
       AES-CCM 3:128-bit txpower 21.5 bmiss 7 scanvalid 450 bgscan
       bgscanintvl 300 bgscanidle 250 roam:rssi 7 roam:rate 5 protmode CTS
       wme burst roaming MANUAL

      32.3.4.1.4. WEP

   Wired Equivalent Privacy (WEP) is part of the original 802.11 standard.
   There is no authentication mechanism, only a weak form of access control
   which is easily cracked.

   WEP can be set up using ifconfig(8):

 # ifconfig wlan0 create wlandev ath0
 # ifconfig wlan0 inet 192.168.1.100 netmask 255.255.255.0 \
             ssid my_net wepmode on weptxkey 3 wepkey 3:0x3456789012

     * The weptxkey specifies which WEP key will be used in the transmission.
       This example uses the third key. This must match the setting on the
       access point. When unsure which key is used by the access point, try 1
       (the first key) for this value.

     * The wepkey selects one of the WEP keys. It should be in the format
       index:key. Key 1 is used by default; the index only needs to be set
       when using a key other than the first key.

  Note:

       Replace the 0x3456789012 with the key configured for use on the access
       point.

   Refer to ifconfig(8) for further information.

   The wpa_supplicant(8) facility can be used to configure a wireless
   interface with WEP. The example above can be set up by adding the
   following lines to /etc/wpa_supplicant.conf:

 network={
   ssid="my_net"
   key_mgmt=NONE
   wep_key3=3456789012
   wep_tx_keyidx=3
 }

   Then:

 # wpa_supplicant -i wlan0 -c /etc/wpa_supplicant.conf
 Trying to associate with 00:13:46:49:41:76 (SSID='dlinkap' freq=2437 MHz)
 Associated with 00:13:46:49:41:76

  32.3.5. Ad-hoc Mode

   IBSS mode, also called ad-hoc mode, is designed for point to point
   connections. For example, to establish an ad-hoc network between the
   machines A and B, choose two IP addresses and a SSID.

   On A:

 # ifconfig wlan0 create wlandev ath0 wlanmode adhoc
 # ifconfig wlan0 inet 192.168.0.1 netmask 255.255.255.0 ssid freebsdap
 # ifconfig wlan0
   wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
           ether 00:11:95:c3:0d:ac
           inet 192.168.0.1 netmask 0xffffff00 broadcast 192.168.0.255
           media: IEEE 802.11 Wireless Ethernet autoselect mode 11g <adhoc>
           status: running
           ssid freebsdap channel 2 (2417 Mhz 11g) bssid 02:11:95:c3:0d:ac
           country US ecm authmode OPEN privacy OFF txpower 21.5 scanvalid 60
           protmode CTS wme burst

   The adhoc parameter indicates that the interface is running in IBSS mode.

   B should now be able to detect A:

 # ifconfig wlan0 create wlandev ath0 wlanmode adhoc
 # ifconfig wlan0 up scan
   SSID/MESH ID    BSSID              CHAN RATE   S:N     INT CAPS
   freebsdap       02:11:95:c3:0d:ac    2   54M -64:-96  100 IS   WME

   The I in the output confirms that A is in ad-hoc mode. Now, configure B
   with a different IP address:

 # ifconfig wlan0 inet 192.168.0.2 netmask 255.255.255.0 ssid freebsdap
 # ifconfig wlan0
   wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
           ether 00:11:95:d5:43:62
           inet 192.168.0.2 netmask 0xffffff00 broadcast 192.168.0.255
           media: IEEE 802.11 Wireless Ethernet autoselect mode 11g <adhoc>
           status: running
           ssid freebsdap channel 2 (2417 Mhz 11g) bssid 02:11:95:c3:0d:ac
           country US ecm authmode OPEN privacy OFF txpower 21.5 scanvalid 60
           protmode CTS wme burst

   Both A and B are now ready to exchange information.

  32.3.6. FreeBSD Host Access Points

   FreeBSD can act as an Access Point (AP) which eliminates the need to buy a
   hardware AP or run an ad-hoc network. This can be particularly useful when
   a FreeBSD machine is acting as a gateway to another network such as the
   Internet.

    32.3.6.1. Basic Settings

   Before configuring a FreeBSD machine as an AP, the kernel must be
   configured with the appropriate networking support for the wireless card
   as well as the security protocols being used. For more details, see
   Section 32.3.3, "Basic Setup".

  Note:

   The NDIS driver wrapper for Windows(R) drivers does not currently support
   AP operation. Only native FreeBSD wireless drivers support AP mode.

   Once wireless networking support is loaded, check if the wireless device
   supports the host-based access point mode, also known as hostap mode:

 # ifconfig wlan0 create wlandev ath0
 # ifconfig wlan0 list caps
 drivercaps=6f85edc1<STA,FF,TURBOP,IBSS,HOSTAP,AHDEMO,TXPMGT,SHSLOT,SHPREAMBLE,MONITOR,MBSS,WPA1,WPA2,BURST,WME,WDS,BGSCAN,TXFRAG>
 cryptocaps=1f<WEP,TKIP,AES,AES_CCM,TKIPMIC>

   This output displays the card's capabilities. The HOSTAP word confirms
   that this wireless card can act as an AP. Various supported ciphers are
   also listed: WEP, TKIP, and AES. This information indicates which security
   protocols can be used on the AP.

   The wireless device can only be put into hostap mode during the creation
   of the network pseudo-device, so a previously created device must be
   destroyed first:

 # ifconfig wlan0 destroy

   then regenerated with the correct option before setting the other
   parameters:

 # ifconfig wlan0 create wlandev ath0 wlanmode hostap
 # ifconfig wlan0 inet 192.168.0.1 netmask 255.255.255.0 ssid freebsdap mode 11g channel 1

   Use ifconfig(8) again to see the status of the wlan0 interface:

 # ifconfig wlan0
   wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
           ether 00:11:95:c3:0d:ac
           inet 192.168.0.1 netmask 0xffffff00 broadcast 192.168.0.255
           media: IEEE 802.11 Wireless Ethernet autoselect mode 11g <hostap>
           status: running
           ssid freebsdap channel 1 (2412 Mhz 11g) bssid 00:11:95:c3:0d:ac
           country US ecm authmode OPEN privacy OFF txpower 21.5 scanvalid 60
           protmode CTS wme burst dtimperiod 1 -dfs

   The hostap parameter indicates the interface is running in the host-based
   access point mode.

   The interface configuration can be done automatically at boot time by
   adding the following lines to /etc/rc.conf:

 wlans_ath0="wlan0"
 create_args_wlan0="wlanmode hostap"
 ifconfig_wlan0="inet 192.168.0.1 netmask 255.255.255.0 ssid freebsdap mode 11g channel 1"

    32.3.6.2. Host-based Access Point Without Authentication or Encryption

   Although it is not recommended to run an AP without any authentication or
   encryption, this is a simple way to check if the AP is working. This
   configuration is also important for debugging client issues.

   Once the AP is configured, initiate a scan from another wireless machine
   to find the AP:

 # ifconfig wlan0 create wlandev ath0
 # ifconfig wlan0 up scan
 SSID/MESH ID    BSSID              CHAN RATE   S:N     INT CAPS
 freebsdap       00:11:95:c3:0d:ac    1   54M -66:-96  100 ES   WME

   The client machine found the AP and can be associated with it:

 # ifconfig wlan0 inet 192.168.0.2 netmask 255.255.255.0 ssid freebsdap
 # ifconfig wlan0
   wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
           ether 00:11:95:d5:43:62
           inet 192.168.0.2 netmask 0xffffff00 broadcast 192.168.0.255
           media: IEEE 802.11 Wireless Ethernet OFDM/54Mbps mode 11g
           status: associated
           ssid freebsdap channel 1 (2412 Mhz 11g) bssid 00:11:95:c3:0d:ac
           country US ecm authmode OPEN privacy OFF txpower 21.5 bmiss 7
           scanvalid 60 bgscan bgscanintvl 300 bgscanidle 250 roam:rssi 7
           roam:rate 5 protmode CTS wme burst

    32.3.6.3. WPA2 Host-based Access Point

   This section focuses on setting up a FreeBSD access point using the WPA2
   security protocol. More details regarding WPA and the configuration of
   WPA-based wireless clients can be found in Section 32.3.4.1.3, "WPA".

   The hostapd(8) daemon is used to deal with client authentication and key
   management on the WPA2-enabled AP.

   The following configuration operations are performed on the FreeBSD
   machine acting as the AP. Once the AP is correctly working, hostapd(8) can
   be automatically started at boot with this line in /etc/rc.conf:

 hostapd_enable="YES"

   Before trying to configure hostapd(8), first configure the basic settings
   introduced in Section 32.3.6.1, "Basic Settings".

      32.3.6.3.1. WPA2-PSK

   WPA2-PSK is intended for small networks where the use of a backend
   authentication server is not possible or desired.

   The configuration is done in /etc/hostapd.conf:

 interface=wlan0                  1
 debug=1                          2
 ctrl_interface=/var/run/hostapd  3
 ctrl_interface_group=wheel       4
 ssid=freebsdap                   5
 wpa=2                            6
 wpa_passphrase=freebsdmall       7
 wpa_key_mgmt=WPA-PSK             8
 wpa_pairwise=CCMP                9

   1 Wireless interface used for the access point.                            
   2 Level of verbosity used during the execution of hostapd(8). A value of 1 
     represents the minimal level.                                            
   3 Pathname of the directory used by hostapd(8) to store domain socket      
     files for communication with external programs such as hostapd_cli(8).   
     The default value is used in this example.                               
   4 The group allowed to access the control interface files.                 
   5 The wireless network name, or SSID, that will appear in wireless scans.  
   6 Enable WPA and specify which WPA authentication protocol will be         
     required. A value of 2 configures the AP for WPA2 and is recommended.    
     Set to 1 only if the obsolete WPA is required.                           
   7 ASCII passphrase for WPA authentication.                                 
                                                                              
       Warning:                                                               
                                                                              
     Always use strong passwords that are at least 8 characters long and made 
     from a rich alphabet so that they will not be easily guessed or          
     attacked.                                                                
   8 The key management protocol to use. This example sets WPA-PSK.           
   9 Encryption algorithms accepted by the access point. In this example,     
     only the CCMP (AES) cipher is accepted. CCMP is an alternative to TKIP   
     and is strongly preferred when possible. TKIP should be allowed only     
     when there are stations incapable of using CCMP.                         

   The next step is to start hostapd(8):

 # service hostapd forcestart

 # ifconfig wlan0
 wlan0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 mtu 1500
         ether 04:f0:21:16:8e:10
         inet6 fe80::6f0:21ff:fe16:8e10%wlan0 prefixlen 64 scopeid 0x9
         nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
         media: IEEE 802.11 Wireless Ethernet autoselect mode 11na <hostap>
         status: running
         ssid No5ignal channel 36 (5180 MHz 11a ht/40+) bssid 04:f0:21:16:8e:10
         country US ecm authmode WPA2/802.11i privacy MIXED deftxkey 2
         AES-CCM 2:128-bit AES-CCM 3:128-bit txpower 17 mcastrate 6 mgmtrate 6
         scanvalid 60 ampdulimit 64k ampdudensity 8 shortgi wme burst
         dtimperiod 1 -dfs
         groups: wlan

   Once the AP is running, the clients can associate with it. See
   Section 32.3.4.1.3, "WPA" for more details. It is possible to see the
   stations associated with the AP using ifconfig wlan0 list sta.

    32.3.6.4. WEP Host-based Access Point

   It is not recommended to use WEP for setting up an AP since there is no
   authentication mechanism and the encryption is easily cracked. Some legacy
   wireless cards only support WEP and these cards will only support an AP
   without authentication or encryption.

   The wireless device can now be put into hostap mode and configured with
   the correct SSID and IP address:

 # ifconfig wlan0 create wlandev ath0 wlanmode hostap
 # ifconfig wlan0 inet 192.168.0.1 netmask 255.255.255.0 \
         ssid freebsdap wepmode on weptxkey 3 wepkey 3:0x3456789012 mode 11g

     * The weptxkey indicates which WEP key will be used in the transmission.
       This example uses the third key as key numbering starts with 1. This
       parameter must be specified in order to encrypt the data.

     * The wepkey sets the selected WEP key. It should be in the format
       index:key. If the index is not given, key 1 is set. The index needs to
       be set when using keys other than the first key.

   Use ifconfig(8) to see the status of the wlan0 interface:

 # ifconfig wlan0
   wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
           ether 00:11:95:c3:0d:ac
           inet 192.168.0.1 netmask 0xffffff00 broadcast 192.168.0.255
           media: IEEE 802.11 Wireless Ethernet autoselect mode 11g <hostap>
           status: running
           ssid freebsdap channel 4 (2427 Mhz 11g) bssid 00:11:95:c3:0d:ac
           country US ecm authmode OPEN privacy ON deftxkey 3 wepkey 3:40-bit
           txpower 21.5 scanvalid 60 protmode CTS wme burst dtimperiod 1 -dfs

   From another wireless machine, it is now possible to initiate a scan to
   find the AP:

 # ifconfig wlan0 create wlandev ath0
 # ifconfig wlan0 up scan
 SSID            BSSID              CHAN RATE  S:N   INT CAPS
 freebsdap       00:11:95:c3:0d:ac    1   54M 22:1   100 EPS

   In this example, the client machine found the AP and can associate with it
   using the correct parameters. See Section 32.3.4.1.4, "WEP" for more
   details.

  32.3.7. Using Both Wired and Wireless Connections

   A wired connection provides better performance and reliability, while a
   wireless connection provides flexibility and mobility. Laptop users
   typically want to roam seamlessly between the two types of connections.

   On FreeBSD, it is possible to combine two or even more network interfaces
   together in a "failover" fashion. This type of configuration uses the most
   preferred and available connection from a group of network interfaces, and
   the operating system switches automatically when the link state changes.

   Link aggregation and failover is covered in Section 32.7, "Link
   Aggregation and Failover" and an example for using both wired and wireless
   connections is provided at Example 32.3, "Failover Mode Between Ethernet
   and Wireless Interfaces".

  32.3.8. Troubleshooting

   This section describes a number of steps to help troubleshoot common
   wireless networking problems.

     * If the access point is not listed when scanning, check that the
       configuration has not limited the wireless device to a limited set of
       channels.

     * If the device cannot associate with an access point, verify that the
       configuration matches the settings on the access point. This includes
       the authentication scheme and any security protocols. Simplify the
       configuration as much as possible. If using a security protocol such
       as WPA or WEP, configure the access point for open authentication and
       no security to see if traffic will pass.

       Debugging support is provided by wpa_supplicant(8). Try running this
       utility manually with -dd and look at the system logs.

     * Once the system can associate with the access point, diagnose the
       network configuration using tools like ping(8).

     * There are many lower-level debugging tools. Debugging messages can be
       enabled in the 802.11 protocol support layer using wlandebug(8). For
       example, to enable console messages related to scanning for access
       points and the 802.11 protocol handshakes required to arrange
       communication:

 # wlandebug -i wlan0 +scan+auth+debug+assoc
   net.wlan.0.debug: 0 => 0xc80000<assoc,auth,scan>

       Many useful statistics are maintained by the 802.11 layer and
       wlanstats, found in /usr/src/tools/tools/net80211, will dump this
       information. These statistics should display all errors identified by
       the 802.11 layer. However, some errors are identified in the device
       drivers that lie below the 802.11 layer so they may not show up. To
       diagnose device-specific problems, refer to the drivers'
       documentation.

   If the above information does not help to clarify the problem, submit a
   problem report and include output from the above tools.

32.4. USB Tethering

   Many cellphones provide the option to share their data connection over USB
   (often called "tethering"). This feature uses one of RNDIS, CDC, or a
   custom Apple(R) iPhone(R)/iPad(R) protocol.

     * Android(TM) devices generally use the urndis(4) driver.

     * Apple(R) devices use the ipheth(4) driver.

     * Older devices will often use the cdce(4) driver.

   Before attaching a device, load the appropriate driver into the kernel:

 # kldload if_urndis
 # kldload if_cdce
 # kldload if_ipheth

   Once the device is attached ue0 will be available for use like a normal
   network device. Be sure that the "USB tethering" option is enabled on the
   device.

   To make this change permanent and load the driver as a module at boot
   time, place the appropriate line of the following in /boot/loader.conf:

 if_urndis_load="YES"
 if_cdce_load="YES"
 if_ipheth_load="YES"

32.5. Bluetooth

   Written by Pav Lucistnik.

   Bluetooth is a wireless technology for creating personal networks
   operating in the 2.4 GHz unlicensed band, with a range of 10 meters.
   Networks are usually formed ad-hoc from portable devices such as cellular
   phones, handhelds, and laptops. Unlike Wi-Fi wireless technology,
   Bluetooth offers higher level service profiles, such as FTP-like file
   servers, file pushing, voice transport, serial line emulation, and more.

   This section describes the use of a USB Bluetooth dongle on a FreeBSD
   system. It then describes the various Bluetooth protocols and utilities.

  32.5.1. Loading Bluetooth Support

   The Bluetooth stack in FreeBSD is implemented using the netgraph(4)
   framework. A broad variety of Bluetooth USB dongles is supported by
   ng_ubt(4). Broadcom BCM2033 based Bluetooth devices are supported by the
   ubtbcmfw(4) and ng_ubt(4) drivers. The 3Com Bluetooth PC Card 3CRWB60-A is
   supported by the ng_bt3c(4) driver. Serial and UART based Bluetooth
   devices are supported by sio(4), ng_h4(4), and hcseriald(8).

   Before attaching a device, determine which of the above drivers it uses,
   then load the driver. For example, if the device uses the ng_ubt(4)
   driver:

 # kldload ng_ubt

   If the Bluetooth device will be attached to the system during system
   startup, the system can be configured to load the module at boot time by
   adding the driver to /boot/loader.conf:

 ng_ubt_load="YES"

   Once the driver is loaded, plug in the USB dongle. If the driver load was
   successful, output similar to the following should appear on the console
   and in /var/log/messages:

 ubt0: vendor 0x0a12 product 0x0001, rev 1.10/5.25, addr 2
 ubt0: Interface 0 endpoints: interrupt=0x81, bulk-in=0x82, bulk-out=0x2
 ubt0: Interface 1 (alt.config 5) endpoints: isoc-in=0x83, isoc-out=0x3,
       wMaxPacketSize=49, nframes=6, buffer size=294

   To start and stop the Bluetooth stack, use its startup script. It is a
   good idea to stop the stack before unplugging the device. Starting the
   bluetooth stack might require hcsecd(8) to be started. When starting the
   stack, the output should be similar to the following:

 # service bluetooth start ubt0
 BD_ADDR: 00:02:72:00:d4:1a
 Features: 0xff 0xff 0xf 00 00 00 00 00
 <3-Slot> <5-Slot> <Encryption> <Slot offset>
 <Timing accuracy> <Switch> <Hold mode> <Sniff mode>
 <Park mode> <RSSI> <Channel quality> <SCO link>
 <HV2 packets> <HV3 packets> <u-law log> <A-law log> <CVSD>
 <Paging scheme> <Power control> <Transparent SCO data>
 Max. ACL packet size: 192 bytes
 Number of ACL packets: 8
 Max. SCO packet size: 64 bytes
 Number of SCO packets: 8

  32.5.2. Finding Other Bluetooth Devices

   The Host Controller Interface (HCI) provides a uniform method for
   accessing Bluetooth baseband capabilities. In FreeBSD, a netgraph HCI node
   is created for each Bluetooth device. For more details, refer to
   ng_hci(4).

   One of the most common tasks is discovery of Bluetooth devices within RF
   proximity. This operation is called inquiry. Inquiry and other HCI related
   operations are done using hccontrol(8). The example below shows how to
   find out which Bluetooth devices are in range. The list of devices should
   be displayed in a few seconds. Note that a remote device will only answer
   the inquiry if it is set to discoverable mode.

 % hccontrol -n ubt0hci inquiry
 Inquiry result, num_responses=1
 Inquiry result #0
        BD_ADDR: 00:80:37:29:19:a4
        Page Scan Rep. Mode: 0x1
        Page Scan Period Mode: 00
        Page Scan Mode: 00
        Class: 52:02:04
        Clock offset: 0x78ef
 Inquiry complete. Status: No error [00]

   The BD_ADDR is the unique address of a Bluetooth device, similar to the
   MAC address of a network card. This address is needed for further
   communication with a device and it is possible to assign a human readable
   name to a BD_ADDR. Information regarding the known Bluetooth hosts is
   contained in /etc/bluetooth/hosts. The following example shows how to
   obtain the human readable name that was assigned to the remote device:

 % hccontrol -n ubt0hci remote_name_request 00:80:37:29:19:a4
 BD_ADDR: 00:80:37:29:19:a4
 Name: Pav's T39

   If an inquiry is performed on a remote Bluetooth device, it will find the
   computer as "your.host.name (ubt0)". The name assigned to the local device
   can be changed at any time.

   Remote devices can be assigned aliases in /etc/bluetooth/hosts. More
   information about /etc/bluetooth/hosts file might be found in
   bluetooth.hosts(5).

   The Bluetooth system provides a point-to-point connection between two
   Bluetooth units, or a point-to-multipoint connection which is shared among
   several Bluetooth devices. The following example shows how to create a
   connection to a remote device:

 % hccontrol -n ubt0hci create_connection BT_ADDR

   create_connection accepts BT_ADDR as well as host aliases in
   /etc/bluetooth/hosts.

   The following example shows how to obtain the list of active baseband
   connections for the local device:

 % hccontrol -n ubt0hci read_connection_list
 Remote BD_ADDR    Handle Type Mode Role Encrypt Pending Queue State
 00:80:37:29:19:a4     41  ACL    0 MAST    NONE       0     0 OPEN

   A connection handle is useful when termination of the baseband connection
   is required, though it is normally not required to do this by hand. The
   stack will automatically terminate inactive baseband connections.

 # hccontrol -n ubt0hci disconnect 41
 Connection handle: 41
 Reason: Connection terminated by local host [0x16]

   Type hccontrol help for a complete listing of available HCI commands. Most
   of the HCI commands do not require superuser privileges.

  32.5.3. Device Pairing

   By default, Bluetooth communication is not authenticated, and any device
   can talk to any other device. A Bluetooth device, such as a cellular
   phone, may choose to require authentication to provide a particular
   service. Bluetooth authentication is normally done with a PIN code, an
   ASCII string up to 16 characters in length. The user is required to enter
   the same PIN code on both devices. Once the user has entered the PIN code,
   both devices will generate a link key. After that, the link key can be
   stored either in the devices or in a persistent storage. Next time, both
   devices will use the previously generated link key. This procedure is
   called pairing. Note that if the link key is lost by either device, the
   pairing must be repeated.

   The hcsecd(8) daemon is responsible for handling Bluetooth authentication
   requests. The default configuration file is /etc/bluetooth/hcsecd.conf. An
   example section for a cellular phone with the PIN code set to 1234 is
   shown below:

 device {
         bdaddr  00:80:37:29:19:a4;
         name    "Pav's T39";
         key     nokey;
         pin     "1234";
       }

   The only limitation on PIN codes is length. Some devices, such as
   Bluetooth headsets, may have a fixed PIN code built in. The -d switch
   forces hcsecd(8) to stay in the foreground, so it is easy to see what is
   happening. Set the remote device to receive pairing and initiate the
   Bluetooth connection to the remote device. The remote device should
   indicate that pairing was accepted and request the PIN code. Enter the
   same PIN code listed in hcsecd.conf. Now the computer and the remote
   device are paired. Alternatively, pairing can be initiated on the remote
   device.

   The following line can be added to /etc/rc.conf to configure hcsecd(8) to
   start automatically on system start:

 hcsecd_enable="YES"

   The following is a sample of the hcsecd(8) daemon output:

 hcsecd[16484]: Got Link_Key_Request event from 'ubt0hci', remote bdaddr 0:80:37:29:19:a4
 hcsecd[16484]: Found matching entry, remote bdaddr 0:80:37:29:19:a4, name 'Pav's T39', link key doesn't exist
 hcsecd[16484]: Sending Link_Key_Negative_Reply to 'ubt0hci' for remote bdaddr 0:80:37:29:19:a4
 hcsecd[16484]: Got PIN_Code_Request event from 'ubt0hci', remote bdaddr 0:80:37:29:19:a4
 hcsecd[16484]: Found matching entry, remote bdaddr 0:80:37:29:19:a4, name 'Pav's T39', PIN code exists
 hcsecd[16484]: Sending PIN_Code_Reply to 'ubt0hci' for remote bdaddr 0:80:37:29:19:a4

  32.5.4. Network Access with PPP Profiles

   A Dial-Up Networking (DUN) profile can be used to configure a cellular
   phone as a wireless modem for connecting to a dial-up Internet access
   server. It can also be used to configure a computer to receive data calls
   from a cellular phone.

   Network access with a PPP profile can be used to provide LAN access for a
   single Bluetooth device or multiple Bluetooth devices. It can also provide
   PC to PC connection using PPP networking over serial cable emulation.

   In FreeBSD, these profiles are implemented with ppp(8) and the
   rfcomm_pppd(8) wrapper which converts a Bluetooth connection into
   something PPP can use. Before a profile can be used, a new PPP label must
   be created in /etc/ppp/ppp.conf. Consult rfcomm_pppd(8) for examples.

   In this example, rfcomm_pppd(8) is used to open a connection to a remote
   device with a BD_ADDR of 00:80:37:29:19:a4 on a DUN RFCOMM channel:

 # rfcomm_pppd -a 00:80:37:29:19:a4 -c -C dun -l rfcomm-dialup

   The actual channel number will be obtained from the remote device using
   the SDP protocol. It is possible to specify the RFCOMM channel by hand,
   and in this case rfcomm_pppd(8) will not perform the SDP query. Use
   sdpcontrol(8) to find out the RFCOMM channel on the remote device.

   In order to provide network access with the PPP LAN service, sdpd(8) must
   be running and a new entry for LAN clients must be created in
   /etc/ppp/ppp.conf. Consult rfcomm_pppd(8) for examples. Finally, start the
   RFCOMM PPP server on a valid RFCOMM channel number. The RFCOMM PPP server
   will automatically register the Bluetooth LAN service with the local SDP
   daemon. The example below shows how to start the RFCOMM PPP server.

 # rfcomm_pppd -s -C 7 -l rfcomm-server

  32.5.5. Bluetooth Protocols

   This section provides an overview of the various Bluetooth protocols,
   their function, and associated utilities.

    32.5.5.1. Logical Link Control and Adaptation Protocol (L2CAP)

   The Logical Link Control and Adaptation Protocol (L2CAP) provides
   connection-oriented and connectionless data services to upper layer
   protocols. L2CAP permits higher level protocols and applications to
   transmit and receive L2CAP data packets up to 64 kilobytes in length.

   L2CAP is based around the concept of channels. A channel is a logical
   connection on top of a baseband connection, where each channel is bound to
   a single protocol in a many-to-one fashion. Multiple channels can be bound
   to the same protocol, but a channel cannot be bound to multiple protocols.
   Each L2CAP packet received on a channel is directed to the appropriate
   higher level protocol. Multiple channels can share the same baseband
   connection.

   In FreeBSD, a netgraph L2CAP node is created for each Bluetooth device.
   This node is normally connected to the downstream Bluetooth HCI node and
   upstream Bluetooth socket nodes. The default name for the L2CAP node is
   "devicel2cap". For more details refer to ng_l2cap(4).

   A useful command is l2ping(8), which can be used to ping other devices.
   Some Bluetooth implementations might not return all of the data sent to
   them, so 0 bytes in the following example is normal.

 # l2ping -a 00:80:37:29:19:a4
 0 bytes from 0:80:37:29:19:a4 seq_no=0 time=48.633 ms result=0
 0 bytes from 0:80:37:29:19:a4 seq_no=1 time=37.551 ms result=0
 0 bytes from 0:80:37:29:19:a4 seq_no=2 time=28.324 ms result=0
 0 bytes from 0:80:37:29:19:a4 seq_no=3 time=46.150 ms result=0

   The l2control(8) utility is used to perform various operations on L2CAP
   nodes. This example shows how to obtain the list of logical connections
   (channels) and the list of baseband connections for the local device:

 % l2control -a 00:02:72:00:d4:1a read_channel_list
 L2CAP channels:
 Remote BD_ADDR     SCID/ DCID   PSM  IMTU/ OMTU State
 00:07:e0:00:0b:ca    66/   64     3   132/  672 OPEN
 % l2control -a 00:02:72:00:d4:1a read_connection_list
 L2CAP connections:
 Remote BD_ADDR    Handle Flags Pending State
 00:07:e0:00:0b:ca     41 O           0 OPEN

   Another diagnostic tool is btsockstat(1). It is similar to netstat(1), but
   for Bluetooth network-related data structures. The example below shows the
   same logical connection as l2control(8) above.

 % btsockstat
 Active L2CAP sockets
 PCB      Recv-Q Send-Q Local address/PSM       Foreign address   CID   State
 c2afe900      0      0 00:02:72:00:d4:1a/3     00:07:e0:00:0b:ca 66    OPEN
 Active RFCOMM sessions
 L2PCB    PCB      Flag MTU   Out-Q DLCs State
 c2afe900 c2b53380 1    127   0     Yes  OPEN
 Active RFCOMM sockets
 PCB      Recv-Q Send-Q Local address     Foreign address   Chan DLCI State
 c2e8bc80      0    250 00:02:72:00:d4:1a 00:07:e0:00:0b:ca 3    6    OPEN

    32.5.5.2. Radio Frequency Communication (RFCOMM)

   The RFCOMM protocol provides emulation of serial ports over the L2CAP
   protocol. RFCOMM is a simple transport protocol, with additional
   provisions for emulating the 9 circuits of RS-232 (EIATIA-232-E) serial
   ports. It supports up to 60 simultaneous connections (RFCOMM channels)
   between two Bluetooth devices.

   For the purposes of RFCOMM, a complete communication path involves two
   applications running on the communication endpoints with a communication
   segment between them. RFCOMM is intended to cover applications that make
   use of the serial ports of the devices in which they reside. The
   communication segment is a direct connect Bluetooth link from one device
   to another.

   RFCOMM is only concerned with the connection between the devices in the
   direct connect case, or between the device and a modem in the network
   case. RFCOMM can support other configurations, such as modules that
   communicate via Bluetooth wireless technology on one side and provide a
   wired interface on the other side.

   In FreeBSD, RFCOMM is implemented at the Bluetooth sockets layer.

    32.5.5.3. Service Discovery Protocol (SDP)

   The Service Discovery Protocol (SDP) provides the means for client
   applications to discover the existence of services provided by server
   applications as well as the attributes of those services. The attributes
   of a service include the type or class of service offered and the
   mechanism or protocol information needed to utilize the service.

   SDP involves communication between a SDP server and a SDP client. The
   server maintains a list of service records that describe the
   characteristics of services associated with the server. Each service
   record contains information about a single service. A client may retrieve
   information from a service record maintained by the SDP server by issuing
   a SDP request. If the client, or an application associated with the
   client, decides to use a service, it must open a separate connection to
   the service provider in order to utilize the service. SDP provides a
   mechanism for discovering services and their attributes, but it does not
   provide a mechanism for utilizing those services.

   Normally, a SDP client searches for services based on some desired
   characteristics of the services. However, there are times when it is
   desirable to discover which types of services are described by an SDP
   server's service records without any prior information about the services.
   This process of looking for any offered services is called browsing.

   The Bluetooth SDP server, sdpd(8), and command line client, sdpcontrol(8),
   are included in the standard FreeBSD installation. The following example
   shows how to perform a SDP browse query.

 % sdpcontrol -a 00:01:03:fc:6e:ec browse
 Record Handle: 00000000
 Service Class ID List:
         Service Discovery Server (0x1000)
 Protocol Descriptor List:
         L2CAP (0x0100)
                 Protocol specific parameter #1: u/int/uuid16 1
                 Protocol specific parameter #2: u/int/uuid16 1

 Record Handle: 0x00000001
 Service Class ID List:
         Browse Group Descriptor (0x1001)

 Record Handle: 0x00000002
 Service Class ID List:
         LAN Access Using PPP (0x1102)
 Protocol Descriptor List:
         L2CAP (0x0100)
         RFCOMM (0x0003)
                 Protocol specific parameter #1: u/int8/bool 1
 Bluetooth Profile Descriptor List:
         LAN Access Using PPP (0x1102) ver. 1.0

   Note that each service has a list of attributes, such as the RFCOMM
   channel. Depending on the service, the user might need to make note of
   some of the attributes. Some Bluetooth implementations do not support
   service browsing and may return an empty list. In this case, it is
   possible to search for the specific service. The example below shows how
   to search for the OBEX Object Push (OPUSH) service:

 % sdpcontrol -a 00:01:03:fc:6e:ec search OPUSH

   Offering services on FreeBSD to Bluetooth clients is done with the sdpd(8)
   server. The following line can be added to /etc/rc.conf:

 sdpd_enable="YES"

   Then the sdpd(8) daemon can be started with:

 # service sdpd start

   The local server application that wants to provide a Bluetooth service to
   remote clients will register the service with the local SDP daemon. An
   example of such an application is rfcomm_pppd(8). Once started, it will
   register the Bluetooth LAN service with the local SDP daemon.

   The list of services registered with the local SDP server can be obtained
   by issuing a SDP browse query via the local control channel:

 # sdpcontrol -l browse

    32.5.5.4. OBEX Object Push (OPUSH)

   Object Exchange (OBEX) is a widely used protocol for simple file transfers
   between mobile devices. Its main use is in infrared communication, where
   it is used for generic file transfers between notebooks or PDAs, and for
   sending business cards or calendar entries between cellular phones and
   other devices with Personal Information Manager (PIM) applications.

   The OBEX server and client are implemented by obexapp, which can be
   installed using the comms/obexapp package or port.

   The OBEX client is used to push and/or pull objects from the OBEX server.
   An example object is a business card or an appointment. The OBEX client
   can obtain the RFCOMM channel number from the remote device via SDP. This
   can be done by specifying the service name instead of the RFCOMM channel
   number. Supported service names are: IrMC, FTRN, and OPUSH. It is also
   possible to specify the RFCOMM channel as a number. Below is an example of
   an OBEX session where the device information object is pulled from the
   cellular phone, and a new object, the business card, is pushed into the
   phone's directory.

 % obexapp -a 00:80:37:29:19:a4 -C IrMC
 obex> get telecom/devinfo.txt devinfo-t39.txt
 Success, response: OK, Success (0x20)
 obex> put new.vcf
 Success, response: OK, Success (0x20)
 obex> di
 Success, response: OK, Success (0x20)

   In order to provide the OPUSH service, sdpd(8) must be running and a root
   folder, where all incoming objects will be stored, must be created. The
   default path to the root folder is /var/spool/obex. Finally, start the
   OBEX server on a valid RFCOMM channel number. The OBEX server will
   automatically register the OPUSH service with the local SDP daemon. The
   example below shows how to start the OBEX server.

 # obexapp -s -C 10

    32.5.5.5. Serial Port Profile (SPP)

   The Serial Port Profile (SPP) allows Bluetooth devices to perform serial
   cable emulation. This profile allows legacy applications to use Bluetooth
   as a cable replacement, through a virtual serial port abstraction.

   In FreeBSD, rfcomm_sppd(1) implements SPP and a pseudo tty is used as a
   virtual serial port abstraction. The example below shows how to connect to
   a remote device's serial port service. A RFCOMM channel does not have to
   be specified as rfcomm_sppd(1) can obtain it from the remote device via
   SDP. To override this, specify a RFCOMM channel on the command line.

 # rfcomm_sppd -a 00:07:E0:00:0B:CA -t
 rfcomm_sppd[94692]: Starting on /dev/pts/6...
 /dev/pts/6

   Once connected, the pseudo tty can be used as serial port:

 # cu -l /dev/pts/6

   The pseudo tty is printed on stdout and can be read by wrapper scripts:

 PTS=`rfcomm_sppd -a 00:07:E0:00:0B:CA -t`
 cu -l $PTS

  32.5.6. Troubleshooting

   By default, when FreeBSD is accepting a new connection, it tries to
   perform a role switch and become master. Some older Bluetooth devices
   which do not support role switching will not be able to connect. Since
   role switching is performed when a new connection is being established, it
   is not possible to ask the remote device if it supports role switching.
   However, there is a HCI option to disable role switching on the local
   side:

 # hccontrol -n ubt0hci write_node_role_switch 0

   To display Bluetooth packets, use the third-party package hcidump, which
   can be installed using the comms/hcidump package or port. This utility is
   similar to tcpdump(1) and can be used to display the contents of Bluetooth
   packets on the terminal and to dump the Bluetooth packets to a file.

32.6. Bridging

   Written by Andrew Thompson.

   It is sometimes useful to divide a network, such as an Ethernet segment,
   into network segments without having to create IP subnets and use a router
   to connect the segments together. A device that connects two networks
   together in this fashion is called a "bridge".

   A bridge works by learning the MAC addresses of the devices on each of its
   network interfaces. It forwards traffic between networks only when the
   source and destination MAC addresses are on different networks. In many
   respects, a bridge is like an Ethernet switch with very few ports. A
   FreeBSD system with multiple network interfaces can be configured to act
   as a bridge.

   Bridging can be useful in the following situations:

   Connecting Networks

           The basic operation of a bridge is to join two or more network
           segments. There are many reasons to use a host-based bridge
           instead of networking equipment, such as cabling constraints or
           firewalling. A bridge can also connect a wireless interface
           running in hostap mode to a wired network and act as an access
           point.

   Filtering/Traffic Shaping Firewall

           A bridge can be used when firewall functionality is needed without
           routing or Network Address Translation (NAT).

           An example is a small company that is connected via DSL or ISDN to
           an ISP. There are thirteen public IP addresses from the ISP and
           ten computers on the network. In this situation, using a
           router-based firewall is difficult because of subnetting issues. A
           bridge-based firewall can be configured without any IP addressing
           issues.

   Network Tap

           A bridge can join two network segments in order to inspect all
           Ethernet frames that pass between them using bpf(4) and tcpdump(1)
           on the bridge interface or by sending a copy of all frames out an
           additional interface known as a span port.

   Layer 2 VPN

           Two Ethernet networks can be joined across an IP link by bridging
           the networks to an EtherIP tunnel or a tap(4) based solution such
           as OpenVPN.

   Layer 2 Redundancy

           A network can be connected together with multiple links and use
           the Spanning Tree Protocol (STP) to block redundant paths.

   This section describes how to configure a FreeBSD system as a bridge using
   if_bridge(4). A netgraph bridging driver is also available, and is
   described in ng_bridge(4).

  Note:

   Packet filtering can be used with any firewall package that hooks into the
   pfil(9) framework. The bridge can be used as a traffic shaper with altq(4)
   or dummynet(4).

  32.6.1. Enabling the Bridge

   In FreeBSD, if_bridge(4) is a kernel module which is automatically loaded
   by ifconfig(8) when creating a bridge interface. It is also possible to
   compile bridge support into a custom kernel by adding device if_bridge to
   the custom kernel configuration file.

   The bridge is created using interface cloning. To create the bridge
   interface:

 # ifconfig bridge create
 bridge0
 # ifconfig bridge0
 bridge0: flags=8802<BROADCAST,SIMPLEX,MULTICAST> metric 0 mtu 1500
         ether 96:3d:4b:f1:79:7a
         id 00:00:00:00:00:00 priority 32768 hellotime 2 fwddelay 15
         maxage 20 holdcnt 6 proto rstp maxaddr 100 timeout 1200
         root id 00:00:00:00:00:00 priority 0 ifcost 0 port 0

   When a bridge interface is created, it is automatically assigned a
   randomly generated Ethernet address. The maxaddr and timeout parameters
   control how many MAC addresses the bridge will keep in its forwarding
   table and how many seconds before each entry is removed after it is last
   seen. The other parameters control how STP operates.

   Next, specify which network interfaces to add as members of the bridge.
   For the bridge to forward packets, all member interfaces and the bridge
   need to be up:

 # ifconfig bridge0 addm fxp0 addm fxp1 up
 # ifconfig fxp0 up
 # ifconfig fxp1 up

   The bridge can now forward Ethernet frames between fxp0 and fxp1. Add the
   following lines to /etc/rc.conf so the bridge is created at startup:

 cloned_interfaces="bridge0"
 ifconfig_bridge0="addm fxp0 addm fxp1 up"
 ifconfig_fxp0="up"
 ifconfig_fxp1="up"

   If the bridge host needs an IP address, set it on the bridge interface,
   not on the member interfaces. The address can be set statically or via
   DHCP. This example sets a static IP address:

 # ifconfig bridge0 inet 192.168.0.1/24

   It is also possible to assign an IPv6 address to a bridge interface. To
   make the changes permanent, add the addressing information to
   /etc/rc.conf.

  Note:

   When packet filtering is enabled, bridged packets will pass through the
   filter inbound on the originating interface on the bridge interface, and
   outbound on the appropriate interfaces. Either stage can be disabled. When
   direction of the packet flow is important, it is best to firewall on the
   member interfaces rather than the bridge itself.

   The bridge has several configurable settings for passing non-IP and IP
   packets, and layer2 firewalling with ipfw(8). See if_bridge(4) for more
   information.

  32.6.2. Enabling Spanning Tree

   For an Ethernet network to function properly, only one active path can
   exist between two devices. The STP protocol detects loops and puts
   redundant links into a blocked state. Should one of the active links fail,
   STP calculates a different tree and enables one of the blocked paths to
   restore connectivity to all points in the network.

   The Rapid Spanning Tree Protocol (RSTP or 802.1w) provides backwards
   compatibility with legacy STP. RSTP provides faster convergence and
   exchanges information with neighboring switches to quickly transition to
   forwarding mode without creating loops. FreeBSD supports RSTP and STP as
   operating modes, with RSTP being the default mode.

   STP can be enabled on member interfaces using ifconfig(8). For a bridge
   with fxp0 and fxp1 as the current interfaces, enable STP with:

 # ifconfig bridge0 stp fxp0 stp fxp1
 bridge0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
         ether d6:cf:d5:a0:94:6d
         id 00:01:02:4b:d4:50 priority 32768 hellotime 2 fwddelay 15
         maxage 20 holdcnt 6 proto rstp maxaddr 100 timeout 1200
         root id 00:01:02:4b:d4:50 priority 32768 ifcost 0 port 0
         member: fxp0 flags=1c7<LEARNING,DISCOVER,STP,AUTOEDGE,PTP,AUTOPTP>
                 port 3 priority 128 path cost 200000 proto rstp
                 role designated state forwarding
         member: fxp1 flags=1c7<LEARNING,DISCOVER,STP,AUTOEDGE,PTP,AUTOPTP>
                 port 4 priority 128 path cost 200000 proto rstp
                 role designated state forwarding

   This bridge has a spanning tree ID of 00:01:02:4b:d4:50 and a priority of
   32768. As the root id is the same, it indicates that this is the root
   bridge for the tree.

   Another bridge on the network also has STP enabled:

 bridge0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
         ether 96:3d:4b:f1:79:7a
         id 00:13:d4:9a:06:7a priority 32768 hellotime 2 fwddelay 15
         maxage 20 holdcnt 6 proto rstp maxaddr 100 timeout 1200
         root id 00:01:02:4b:d4:50 priority 32768 ifcost 400000 port 4
         member: fxp0 flags=1c7<LEARNING,DISCOVER,STP,AUTOEDGE,PTP,AUTOPTP>
                 port 4 priority 128 path cost 200000 proto rstp
                 role root state forwarding
         member: fxp1 flags=1c7<LEARNING,DISCOVER,STP,AUTOEDGE,PTP,AUTOPTP>
                 port 5 priority 128 path cost 200000 proto rstp
                 role designated state forwarding

   The line root id 00:01:02:4b:d4:50 priority 32768 ifcost 400000 port 4
   shows that the root bridge is 00:01:02:4b:d4:50 and has a path cost of
   400000 from this bridge. The path to the root bridge is via port 4 which
   is fxp0.

  32.6.3. Bridge Interface Parameters

   Several ifconfig parameters are unique to bridge interfaces. This section
   summarizes some common uses for these parameters. The complete list of
   available parameters is described in ifconfig(8).

   private

           A private interface does not forward any traffic to any other port
           that is also designated as a private interface. The traffic is
           blocked unconditionally so no Ethernet frames will be forwarded,
           including ARP packets. If traffic needs to be selectively blocked,
           a firewall should be used instead.

   span

           A span port transmits a copy of every Ethernet frame received by
           the bridge. The number of span ports configured on a bridge is
           unlimited, but if an interface is designated as a span port, it
           cannot also be used as a regular bridge port. This is most useful
           for snooping a bridged network passively on another host connected
           to one of the span ports of the bridge. For example, to send a
           copy of all frames out the interface named fxp4:

 # ifconfig bridge0 span fxp4

   sticky

           If a bridge member interface is marked as sticky, dynamically
           learned address entries are treated as static entries in the
           forwarding cache. Sticky entries are never aged out of the cache
           or replaced, even if the address is seen on a different interface.
           This gives the benefit of static address entries without the need
           to pre-populate the forwarding table. Clients learned on a
           particular segment of the bridge cannot roam to another segment.

           An example of using sticky addresses is to combine the bridge with
           VLANs in order to isolate customer networks without wasting IP
           address space. Consider that CustomerA is on vlan100, CustomerB is
           on vlan101, and the bridge has the address 192.168.0.1:

 # ifconfig bridge0 addm vlan100 sticky vlan100 addm vlan101 sticky vlan101
 # ifconfig bridge0 inet 192.168.0.1/24

           In this example, both clients see 192.168.0.1 as their default
           gateway. Since the bridge cache is sticky, one host cannot spoof
           the MAC address of the other customer in order to intercept their
           traffic.

           Any communication between the VLANs can be blocked using a
           firewall or, as seen in this example, private interfaces:

 # ifconfig bridge0 private vlan100 private vlan101

           The customers are completely isolated from each other and the full
           /24 address range can be allocated without subnetting.

           The number of unique source MAC addresses behind an interface can
           be limited. Once the limit is reached, packets with unknown source
           addresses are dropped until an existing host cache entry expires
           or is removed.

           The following example sets the maximum number of Ethernet devices
           for CustomerA on vlan100 to 10:

 # ifconfig bridge0 ifmaxaddr vlan100 10

   Bridge interfaces also support monitor mode, where the packets are
   discarded after bpf(4) processing and are not processed or forwarded
   further. This can be used to multiplex the input of two or more interfaces
   into a single bpf(4) stream. This is useful for reconstructing the traffic
   for network taps that transmit the RX/TX signals out through two separate
   interfaces. For example, to read the input from four network interfaces as
   one stream:

 # ifconfig bridge0 addm fxp0 addm fxp1 addm fxp2 addm fxp3 monitor up
 # tcpdump -i bridge0

  32.6.4. SNMP Monitoring

   The bridge interface and STP parameters can be monitored via bsnmpd(1)
   which is included in the FreeBSD base system. The exported bridge MIBs
   conform to IETF standards so any SNMP client or monitoring package can be
   used to retrieve the data.

   To enable monitoring on the bridge, uncomment this line in
   /etc/snmpd.config by removing the beginning # symbol:

 begemotSnmpdModulePath."bridge" = "/usr/lib/snmp_bridge.so"

   Other configuration settings, such as community names and access lists,
   may need to be modified in this file. See bsnmpd(1) and snmp_bridge(3) for
   more information. Once these edits are saved, add this line to
   /etc/rc.conf:

 bsnmpd_enable="YES"

   Then, start bsnmpd(1):

 # service bsnmpd start

   The following examples use the Net-SNMP software (net-mgmt/net-snmp) to
   query a bridge from a client system. The net-mgmt/bsnmptools port can also
   be used. From the SNMP client which is running Net-SNMP, add the following
   lines to $HOME/.snmp/snmp.conf in order to import the bridge MIB
   definitions:

 mibdirs +/usr/share/snmp/mibs
 mibs +BRIDGE-MIB:RSTP-MIB:BEGEMOT-MIB:BEGEMOT-BRIDGE-MIB

   To monitor a single bridge using the IETF BRIDGE-MIB (RFC4188):

 % snmpwalk -v 2c -c public bridge1.example.com mib-2.dot1dBridge
 BRIDGE-MIB::dot1dBaseBridgeAddress.0 = STRING: 66:fb:9b:6e:5c:44
 BRIDGE-MIB::dot1dBaseNumPorts.0 = INTEGER: 1 ports
 BRIDGE-MIB::dot1dStpTimeSinceTopologyChange.0 = Timeticks: (189959) 0:31:39.59 centi-seconds
 BRIDGE-MIB::dot1dStpTopChanges.0 = Counter32: 2
 BRIDGE-MIB::dot1dStpDesignatedRoot.0 = Hex-STRING: 80 00 00 01 02 4B D4 50
 ...
 BRIDGE-MIB::dot1dStpPortState.3 = INTEGER: forwarding(5)
 BRIDGE-MIB::dot1dStpPortEnable.3 = INTEGER: enabled(1)
 BRIDGE-MIB::dot1dStpPortPathCost.3 = INTEGER: 200000
 BRIDGE-MIB::dot1dStpPortDesignatedRoot.3 = Hex-STRING: 80 00 00 01 02 4B D4 50
 BRIDGE-MIB::dot1dStpPortDesignatedCost.3 = INTEGER: 0
 BRIDGE-MIB::dot1dStpPortDesignatedBridge.3 = Hex-STRING: 80 00 00 01 02 4B D4 50
 BRIDGE-MIB::dot1dStpPortDesignatedPort.3 = Hex-STRING: 03 80
 BRIDGE-MIB::dot1dStpPortForwardTransitions.3 = Counter32: 1
 RSTP-MIB::dot1dStpVersion.0 = INTEGER: rstp(2)

   The dot1dStpTopChanges.0 value is two, indicating that the STP bridge
   topology has changed twice. A topology change means that one or more links
   in the network have changed or failed and a new tree has been calculated.
   The dot1dStpTimeSinceTopologyChange.0 value will show when this happened.

   To monitor multiple bridge interfaces, the private BEGEMOT-BRIDGE-MIB can
   be used:

 % snmpwalk -v 2c -c public bridge1.example.com
 enterprises.fokus.begemot.begemotBridge
 BEGEMOT-BRIDGE-MIB::begemotBridgeBaseName."bridge0" = STRING: bridge0
 BEGEMOT-BRIDGE-MIB::begemotBridgeBaseName."bridge2" = STRING: bridge2
 BEGEMOT-BRIDGE-MIB::begemotBridgeBaseAddress."bridge0" = STRING: e:ce:3b:5a:9e:13
 BEGEMOT-BRIDGE-MIB::begemotBridgeBaseAddress."bridge2" = STRING: 12:5e:4d:74:d:fc
 BEGEMOT-BRIDGE-MIB::begemotBridgeBaseNumPorts."bridge0" = INTEGER: 1
 BEGEMOT-BRIDGE-MIB::begemotBridgeBaseNumPorts."bridge2" = INTEGER: 1
 ...
 BEGEMOT-BRIDGE-MIB::begemotBridgeStpTimeSinceTopologyChange."bridge0" = Timeticks: (116927) 0:19:29.27 centi-seconds
 BEGEMOT-BRIDGE-MIB::begemotBridgeStpTimeSinceTopologyChange."bridge2" = Timeticks: (82773) 0:13:47.73 centi-seconds
 BEGEMOT-BRIDGE-MIB::begemotBridgeStpTopChanges."bridge0" = Counter32: 1
 BEGEMOT-BRIDGE-MIB::begemotBridgeStpTopChanges."bridge2" = Counter32: 1
 BEGEMOT-BRIDGE-MIB::begemotBridgeStpDesignatedRoot."bridge0" = Hex-STRING: 80 00 00 40 95 30 5E 31
 BEGEMOT-BRIDGE-MIB::begemotBridgeStpDesignatedRoot."bridge2" = Hex-STRING: 80 00 00 50 8B B8 C6 A9

   To change the bridge interface being monitored via the mib-2.dot1dBridge
   subtree:

 % snmpset -v 2c -c private bridge1.example.com
 BEGEMOT-BRIDGE-MIB::begemotBridgeDefaultBridgeIf.0 s bridge2

32.7. Link Aggregation and Failover

   Written by Andrew Thompson.

   FreeBSD provides the lagg(4) interface which can be used to aggregate
   multiple network interfaces into one virtual interface in order to provide
   failover and link aggregation. Failover allows traffic to continue to flow
   as long as at least one aggregated network interface has an established
   link. Link aggregation works best on switches which support LACP, as this
   protocol distributes traffic bi-directionally while responding to the
   failure of individual links.

   The aggregation protocols supported by the lagg interface determine which
   ports are used for outgoing traffic and whether or not a specific port
   accepts incoming traffic. The following protocols are supported by
   lagg(4):

   failover

           This mode sends and receives traffic only through the master port.
           If the master port becomes unavailable, the next active port is
           used. The first interface added to the virtual interface is the
           master port and all subsequently added interfaces are used as
           failover devices. If failover to a non-master port occurs, the
           original port becomes master once it becomes available again.

   fec / loadbalance

           Cisco(R) Fast EtherChannel(R) (FEC) is found on older Cisco(R)
           switches. It provides a static setup and does not negotiate
           aggregation with the peer or exchange frames to monitor the link.
           If the switch supports LACP, that should be used instead.

   lacp

           The IEEE(R) 802.3ad Link Aggregation Control Protocol (LACP)
           negotiates a set of aggregable links with the peer into one or
           more Link Aggregated Groups (LAGs). Each LAG is composed of ports
           of the same speed, set to full-duplex operation, and traffic is
           balanced across the ports in the LAG with the greatest total
           speed. Typically, there is only one LAG which contains all the
           ports. In the event of changes in physical connectivity, LACP will
           quickly converge to a new configuration.

           LACP balances outgoing traffic across the active ports based on
           hashed protocol header information and accepts incoming traffic
           from any active port. The hash includes the Ethernet source and
           destination address and, if available, the VLAN tag, and the IPv4
           or IPv6 source and destination address.

   roundrobin

           This mode distributes outgoing traffic using a round-robin
           scheduler through all active ports and accepts incoming traffic
           from any active port. Since this mode violates Ethernet frame
           ordering, it should be used with caution.

  32.7.1. Configuration Examples

   This section demonstrates how to configure a Cisco(R) switch and a FreeBSD
   system for LACP load balancing. It then shows how to configure two
   Ethernet interfaces in failover mode as well as how to configure failover
   mode between an Ethernet and a wireless interface.

   Example 32.1. LACP Aggregation with a Cisco(R) Switch

   This example connects two fxp(4) Ethernet interfaces on a FreeBSD machine
   to the first two Ethernet ports on a Cisco(R) switch as a single load
   balanced and fault tolerant link. More interfaces can be added to increase
   throughput and fault tolerance. Replace the names of the Cisco(R) ports,
   Ethernet devices, channel group number, and IP address shown in the
   example to match the local configuration.

   Frame ordering is mandatory on Ethernet links and any traffic between two
   stations always flows over the same physical link, limiting the maximum
   speed to that of one interface. The transmit algorithm attempts to use as
   much information as it can to distinguish different traffic flows and
   balance the flows across the available interfaces.

   On the Cisco(R) switch, add the FastEthernet0/1 and FastEthernet0/2
   interfaces to channel group 1:

 interface FastEthernet0/1
  channel-group 1 mode active
  channel-protocol lacp
 !
 interface FastEthernet0/2
  channel-group 1 mode active
  channel-protocol lacp

   On the FreeBSD system, create the lagg(4) interface using the physical
   interfaces fxp0 and fxp1 and bring the interfaces up with an IP address of
   10.0.0.3/24:

 # ifconfig fxp0 up
 # ifconfig fxp1 up
 # ifconfig lagg0 create
 # ifconfig lagg0 up laggproto lacp laggport fxp0 laggport fxp1 10.0.0.3/24

   Next, verify the status of the virtual interface:

 # ifconfig lagg0
 lagg0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
         options=8<VLAN_MTU>
         ether 00:05:5d:71:8d:b8
         inet 10.0.0.3 netmask 0xffffff00 broadcast 10.0.0.255
         media: Ethernet autoselect
         status: active
         laggproto lacp
         laggport: fxp1 flags=1c<ACTIVE,COLLECTING,DISTRIBUTING>
         laggport: fxp0 flags=1c<ACTIVE,COLLECTING,DISTRIBUTING>

   Ports marked as ACTIVE are part of the LAG that has been negotiated with
   the remote switch. Traffic will be transmitted and received through these
   active ports. Add -v to the above command to view the LAG identifiers.

   To see the port status on the Cisco(R) switch:

 switch# show lacp neighbor
 Flags:  S - Device is requesting Slow LACPDUs
         F - Device is requesting Fast LACPDUs
         A - Device is in Active mode       P - Device is in Passive mode

 Channel group 1 neighbors

 Partner's information:

                   LACP port                        Oper    Port     Port
 Port      Flags   Priority  Dev ID         Age     Key     Number   State
 Fa0/1     SA      32768     0005.5d71.8db8  29s    0x146   0x3      0x3D
 Fa0/2     SA      32768     0005.5d71.8db8  29s    0x146   0x4      0x3D

   For more detail, type show lacp neighbor detail.

   To retain this configuration across reboots, add the following entries to
   /etc/rc.conf on the FreeBSD system:

 ifconfig_fxp0="up"
 ifconfig_fxp1="up"
 cloned_interfaces="lagg0"
 ifconfig_lagg0="laggproto lacp laggport fxp0 laggport fxp1 10.0.0.3/24"

   Example 32.2. Failover Mode

   Failover mode can be used to switch over to a secondary interface if the
   link is lost on the master interface. To configure failover, make sure
   that the underlying physical interfaces are up, then create the lagg(4)
   interface. In this example, fxp0 is the master interface, fxp1 is the
   secondary interface, and the virtual interface is assigned an IP address
   of 10.0.0.15/24:

 # ifconfig fxp0 up
 # ifconfig fxp1 up
 # ifconfig lagg0 create
 # ifconfig lagg0 up laggproto failover laggport fxp0 laggport fxp1 10.0.0.15/24

   The virtual interface should look something like this:

 # ifconfig lagg0
 lagg0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
         options=8<VLAN_MTU>
         ether 00:05:5d:71:8d:b8
         inet 10.0.0.15 netmask 0xffffff00 broadcast 10.0.0.255
         media: Ethernet autoselect
         status: active
         laggproto failover
         laggport: fxp1 flags=0<>
         laggport: fxp0 flags=5<MASTER,ACTIVE>

   Traffic will be transmitted and received on fxp0. If the link is lost on
   fxp0, fxp1 will become the active link. If the link is restored on the
   master interface, it will once again become the active link.

   To retain this configuration across reboots, add the following entries to
   /etc/rc.conf:

 ifconfig_fxp0="up"
 ifconfig_fxp1="up"
 cloned_interfaces="lagg0"
 ifconfig_lagg0="laggproto failover laggport fxp0 laggport fxp1 10.0.0.15/24"

   Example 32.3. Failover Mode Between Ethernet and Wireless Interfaces

   For laptop users, it is usually desirable to configure the wireless device
   as a secondary which is only used when the Ethernet connection is not
   available. With lagg(4), it is possible to configure a failover which
   prefers the Ethernet connection for both performance and security reasons,
   while maintaining the ability to transfer data over the wireless
   connection.

   This is achieved by overriding the Ethernet interface's MAC address with
   that of the wireless interface.

  Note:

   In theory, either the Ethernet or wireless MAC address can be changed to
   match the other. However, some popular wireless interfaces lack support
   for overriding the MAC address. We therefore recommend overriding the
   Ethernet MAC address for this purpose.

  Note:

   If the driver for the wireless interface is not loaded in the GENERIC or
   custom kernel, and the computer is running FreeBSD 12.1, load the
   corresponding .ko in /boot/loader.conf by adding driver_load="YES" to that
   file and rebooting. Another, better way is to load the driver in
   /etc/rc.conf by adding it to kld_list (see rc.conf(5) for details) in that
   file and rebooting. This is needed because otherwise the driver is not
   loaded yet at the time the lagg(4) interface is set up.

   In this example, the Ethernet interface, re0, is the master and the
   wireless interface, wlan0, is the failover. The wlan0 interface was
   created from the ath0 physical wireless interface, and the Ethernet
   interface will be configured with the MAC address of the wireless
   interface. First, determine the MAC address of the wireless interface:

 # ifconfig wlan0
 wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
         ether b8:ee:65:5b:32:59
         groups: wlan
         ssid Bbox-A3BD2403 channel 6 (2437 MHz 11g ht/20) bssid 00:37:b7:56:4b:60
         regdomain ETSI country FR indoor ecm authmode WPA2/802.11i privacy ON
         deftxkey UNDEF AES-CCM 2:128-bit txpower 30 bmiss 7 scanvalid 60
         protmode CTS ampdulimit 64k ampdudensity 8 shortgi -stbctx stbcrx
         -ldpc wme burst roaming MANUAL
         media: IEEE 802.11 Wireless Ethernet MCS mode 11ng
         status: associated
         nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>

   Replace wlan0 to match the system's wireless interface name. The ether
   line will contain the MAC address of the specified interface. Now, change
   the MAC address of the Ethernet interface:

 # ifconfig re0 ether b8:ee:65:5b:32:59

   Bring the wireless interface up (replacing FR with your own 2-letter
   country code), but do not set an IP address:

 # ifconfig wlan0 create wlandev ath0 country FR ssid my_router up

   Make sure the re0 interface is up, then create the lagg(4) interface with
   re0 as master with failover to wlan0:

 # ifconfig re0 up
 # ifconfig lagg0 create
 # ifconfig lagg0 up laggproto failover laggport re0 laggport wlan0

   The virtual interface should look something like this:

 # ifconfig lagg0
 lagg0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
         options=8<VLAN_MTU>
         ether b8:ee:65:5b:32:59
         laggproto failover lagghash l2,l3,l4
         laggport: re0 flags=5<MASTER,ACTIVE>
         laggport: wlan0 flags=0<>
         groups: lagg
         media: Ethernet autoselect
         status: active

   Then, start the DHCP client to obtain an IP address:

 # dhclient lagg0

   To retain this configuration across reboots, add the following entries to
   /etc/rc.conf:

 ifconfig_re0="ether b8:ee:65:5b:32:59"
 wlans_ath0="wlan0"
 ifconfig_wlan0="WPA"
 create_args_wlan0="country FR"
 cloned_interfaces="lagg0"
 ifconfig_lagg0="up laggproto failover laggport re0 laggport wlan0 DHCP"

32.8. Diskless Operation with PXE

   Updated by Jean-Franc,ois Dockes.
   Reorganized and enhanced by Alex Dupre.

   The Intel(R) Preboot eXecution Environment (PXE) allows an operating
   system to boot over the network. For example, a FreeBSD system can boot
   over the network and operate without a local disk, using file systems
   mounted from an NFS server. PXE support is usually available in the BIOS.
   To use PXE when the machine starts, select the Boot from network option in
   the BIOS setup or type a function key during system initialization.

   In order to provide the files needed for an operating system to boot over
   the network, a PXE setup also requires properly configured DHCP, TFTP, and
   NFS servers, where:

     * Initial parameters, such as an IP address, executable boot filename
       and location, server name, and root path are obtained from the DHCP
       server.

     * The operating system loader file is booted using TFTP.

     * The file systems are loaded using NFS.

   When a computer PXE boots, it receives information over DHCP about where
   to obtain the initial boot loader file. After the host computer receives
   this information, it downloads the boot loader via TFTP and then executes
   the boot loader. In FreeBSD, the boot loader file is /boot/pxeboot. After
   /boot/pxeboot executes, the FreeBSD kernel is loaded and the rest of the
   FreeBSD bootup sequence proceeds, as described in Chapter 13, The FreeBSD
   Booting Process.

   This section describes how to configure these services on a FreeBSD system
   so that other systems can PXE boot into FreeBSD. Refer to diskless(8) for
   more information.

  Caution:

   As described, the system providing these services is insecure. It should
   live in a protected area of a network and be untrusted by other hosts.

  32.8.1. Setting Up the PXE Environment

   Written by Craig Rodrigues.

   The steps shown in this section configure the built-in NFS and TFTP
   servers. The next section demonstrates how to install and configure the
   DHCP server. In this example, the directory which will contain the files
   used by PXE users is /b/tftpboot/FreeBSD/install. It is important that
   this directory exists and that the same directory name is set in both
   /etc/inetd.conf and /usr/local/etc/dhcpd.conf.

  Note:

   The command examples below assume use of the sh(1) shell. csh(1) and
   tcsh(1) users will need to start a sh(1) shell or adapt the commands to
   csh(1) syntax.

    1. Create the root directory which will contain a FreeBSD installation to
       be NFS mounted:

 # export NFSROOTDIR=/b/tftpboot/FreeBSD/install
 # mkdir -p ${NFSROOTDIR}

    2. Enable the NFS server by adding this line to /etc/rc.conf:

 nfs_server_enable="YES"

    3. Export the diskless root directory via NFS by adding the following to
       /etc/exports:

 /b -ro -alldirs -maproot=root

    4. Start the NFS server:

 # service nfsd start

    5. Enable inetd(8) by adding the following line to /etc/rc.conf:

 inetd_enable="YES"

    6. Uncomment the following line in /etc/inetd.conf by making sure it does
       not start with a # symbol:

 tftp dgram udp wait root /usr/libexec/tftpd tftpd -l -s /b/tftpboot

  Note:

       Some PXE versions require the TCP version of TFTP. In this case,
       uncomment the second tftp line which contains stream tcp.

    7. Start inetd(8):

 # service inetd start

    8. Install the base system into ${NFSROOTDIR}, either by decompressing
       the official archives or by rebuilding the FreeBSD kernel and userland
       (refer to Section 24.5, "Updating FreeBSD from Source" for more
       detailed instructions, but do not forget to add DESTDIR=${NFSROOTDIR}
       when running the make installkernel and make installworld commands.

    9. Test that the TFTP server works and can download the boot loader which
       will be obtained via PXE:

 # tftp localhost
 tftp> get FreeBSD/install/boot/pxeboot
 Received 264951 bytes in 0.1 seconds

   10. Edit ${NFSROOTDIR}/etc/fstab and create an entry to mount the root
       file system over NFS:

 # Device                                         Mountpoint    FSType   Options  Dump Pass
 myhost.example.com:/b/tftpboot/FreeBSD/install       /         nfs      ro        0    0

       Replace myhost.example.com with the hostname or IP address of the NFS
       server. In this example, the root file system is mounted read-only in
       order to prevent NFS clients from potentially deleting the contents of
       the root file system.

   11. Set the root password in the PXE environment for client machines which
       are PXE booting :

 # chroot ${NFSROOTDIR}
 # passwd

   12. If needed, enable ssh(1) root logins for client machines which are PXE
       booting by editing ${NFSROOTDIR}/etc/ssh/sshd_config and enabling
       PermitRootLogin. This option is documented in sshd_config(5).

   13. Perform any other needed customizations of the PXE environment in
       ${NFSROOTDIR}. These customizations could include things like
       installing packages or editing the password file with vipw(8).

   When booting from an NFS root volume, /etc/rc detects the NFS boot and
   runs /etc/rc.initdiskless. In this case, /etc and /var need to be memory
   backed file systems so that these directories are writable but the NFS
   root directory is read-only:

 # chroot ${NFSROOTDIR}
 # mkdir -p conf/base
 # tar -c -v -f conf/base/etc.cpio.gz --format cpio --gzip etc
 # tar -c -v -f conf/base/var.cpio.gz --format cpio --gzip var

   When the system boots, memory file systems for /etc and /var will be
   created and mounted and the contents of the cpio.gz files will be copied
   into them. By default, these file systems have a maximum capacity of 5
   megabytes. If your archives do not fit, which is usually the case for /var
   when binary packages have been installed, request a larger size by putting
   the number of 512 byte sectors needed (e.g., 5 megabytes is 10240 sectors)
   in ${NFSROOTDIR}/conf/base/etc/md_size and
   ${NFSROOTDIR}/conf/base/var/md_size files for /etc and /var file systems
   respectively.

  32.8.2. Configuring the DHCP Server

   The DHCP server does not need to be the same machine as the TFTP and NFS
   server, but it needs to be accessible in the network.

   DHCP is not part of the FreeBSD base system but can be installed using the
   net/isc-dhcp43-server port or package.

   Once installed, edit the configuration file, /usr/local/etc/dhcpd.conf.
   Configure the next-server, filename, and root-path settings as seen in
   this example:

 subnet 192.168.0.0 netmask 255.255.255.0 {
    range 192.168.0.2 192.168.0.3 ;
    option subnet-mask 255.255.255.0 ;
    option routers 192.168.0.1 ;
    option broadcast-address 192.168.0.255 ;
    option domain-name-servers 192.168.35.35, 192.168.35.36 ;
    option domain-name "example.com";

    # IP address of TFTP server
    next-server 192.168.0.1 ;

    # path of boot loader obtained via tftp
    filename "FreeBSD/install/boot/pxeboot" ;

    # pxeboot boot loader will try to NFS mount this directory for root FS
    option root-path "192.168.0.1:/b/tftpboot/FreeBSD/install/" ;

 }

   The next-server directive is used to specify the IP address of the TFTP
   server.

   The filename directive defines the path to /boot/pxeboot. A relative
   filename is used, meaning that /b/tftpboot is not included in the path.

   The root-path option defines the path to the NFS root file system.

   Once the edits are saved, enable DHCP at boot time by adding the following
   line to /etc/rc.conf:

 dhcpd_enable="YES"

   Then start the DHCP service:

 # service isc-dhcpd start

  32.8.3. Debugging PXE Problems

   Once all of the services are configured and started, PXE clients should be
   able to automatically load FreeBSD over the network. If a particular
   client is unable to connect, when that client machine boots up, enter the
   BIOS configuration menu and confirm that it is set to boot from the
   network.

   This section describes some troubleshooting tips for isolating the source
   of the configuration problem should no clients be able to PXE boot.

    1. Use the net/wireshark package or port to debug the network traffic
       involved during the PXE booting process, which is illustrated in the
       diagram below.

       Figure 32.1. PXE Booting Process with NFS Root Mount
       PXE Booting Process with NFS Root Mount

       1 Client broadcasts a DHCPDISCOVER message.                            
       2 The DHCP server responds with the IP address, next-server, filename, 
         and root-path values.                                                
       3 The client sends a TFTP request to next-server, asking to retrieve   
         filename.                                                            
       4 The TFTP server responds and sends filename to client.               
       5 The client executes filename, which is pxeboot(8), which then loads  
         the kernel. When the kernel executes, the root file system specified 
         by root-path is mounted over NFS.                                    

    2. On the TFTP server, read /var/log/xferlog to ensure that pxeboot is
       being retrieved from the correct location. To test this example
       configuration:

 # tftp 192.168.0.1
 tftp> get FreeBSD/install/boot/pxeboot
 Received 264951 bytes in 0.1 seconds

       The BUGS sections in tftpd(8) and tftp(1) document some limitations
       with TFTP.

    3. Make sure that the root file system can be mounted via NFS. To test
       this example configuration:

 # mount -t nfs 192.168.0.1:/b/tftpboot/FreeBSD/install /mnt

32.9. IPv6

   Originally Written by Aaron Kaplan.
   Restructured and Added by Tom Rhodes.
   Extended by Brad Davis.

   IPv6 is the new version of the well known IP protocol, also known as IPv4.
   IPv6 provides several advantages over IPv4 as well as many new features:

     * Its 128-bit address space allows for
       340,282,366,920,938,463,463,374,607,431,768,211,456 addresses. This
       addresses the IPv4 address shortage and eventual IPv4 address
       exhaustion.

     * Routers only store network aggregation addresses in their routing
       tables, thus reducing the average space of a routing table to 8192
       entries. This addresses the scalability issues associated with IPv4,
       which required every allocated block of IPv4 addresses to be exchanged
       between Internet routers, causing their routing tables to become too
       large to allow efficient routing.

     * Address autoconfiguration (RFC2462).

     * Mandatory multicast addresses.

     * Built-in IPsec (IP security).

     * Simplified header structure.

     * Support for mobile IP.

     * IPv6-to-IPv4 transition mechanisms.

   FreeBSD includes the http://www.kame.net/ IPv6 reference implementation
   and comes with everything needed to use IPv6. This section focuses on
   getting IPv6 configured and running.

  32.9.1. Background on IPv6 Addresses

   There are three different types of IPv6 addresses:

   Unicast

           A packet sent to a unicast address arrives at the interface
           belonging to the address.

   Anycast

           These addresses are syntactically indistinguishable from unicast
           addresses but they address a group of interfaces. The packet
           destined for an anycast address will arrive at the nearest router
           interface. Anycast addresses are only used by routers.

   Multicast

           These addresses identify a group of interfaces. A packet destined
           for a multicast address will arrive at all interfaces belonging to
           the multicast group. The IPv4 broadcast address, usually
           xxx.xxx.xxx.255, is expressed by multicast addresses in IPv6.

   When reading an IPv6 address, the canonical form is represented as
   x:x:x:x:x:x:x:x, where each x represents a 16 bit hex value. An example is
   FEBC:A574:382B:23C1:AA49:4592:4EFE:9982.

   Often, an address will have long substrings of all zeros. A :: (double
   colon) can be used to replace one substring per address. Also, up to three
   leading 0s per hex value can be omitted. For example, fe80::1 corresponds
   to the canonical form fe80:0000:0000:0000:0000:0000:0000:0001.

   A third form is to write the last 32 bits using the well known IPv4
   notation. For example, 2002::10.0.0.1 corresponds to the hexadecimal
   canonical representation 2002:0000:0000:0000:0000:0000:0a00:0001, which in
   turn is equivalent to 2002::a00:1.

   To view a FreeBSD system's IPv6 address, use ifconfig(8):

 # ifconfig

 rl0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
          inet 10.0.0.10 netmask 0xffffff00 broadcast 10.0.0.255
          inet6 fe80::200:21ff:fe03:8e1%rl0 prefixlen 64 scopeid 0x1
          ether 00:00:21:03:08:e1
          media: Ethernet autoselect (100baseTX )
          status: active

   In this example, the rl0 interface is using fe80::200:21ff:fe03:8e1%rl0,
   an auto-configured link-local address which was automatically generated
   from the MAC address.

   Some IPv6 addresses are reserved. A summary of these reserved addresses is
   seen in Table 32.3, "Reserved IPv6 Addresses":

   Table 32.3. Reserved IPv6 Addresses

     IPv6 address   Prefixlength   Description               Notes            
                       (Bits)    
   ::               128 bits     unspecified      Equivalent to 0.0.0.0 in    
                                                  IPv4.                       
   ::1              128 bits     loopback address Equivalent to 127.0.0.1 in  
                                                  IPv4.                       
   ::00:xx:xx:xx:xx 96 bits      embedded IPv4    The lower 32 bits are the   
                                                  compatible IPv4 address.    
                                 IPv4 mapped IPv6 The lower 32 bits are the   
   ::ff:xx:xx:xx:xx 96 bits      address          IPv4 address for hosts      
                                                  which do not support IPv6.  
   fe80::/10        10 bits      link-local       Equivalent to               
                                                  169.254.0.0/16 in IPv4.     
                                                  Unique local addresses are  
                                                  intended for local          
   fc00::/7         7 bits       unique-local     communication and are only  
                                                  routable within a set of    
                                                  cooperating sites.          
   ff00::           8 bits       multicast                                    
                                                  All global unicast          
   2000::-3fff::    3 bits       global unicast   addresses are assigned from 
                                                  this pool. The first 3 bits 
                                                  are 001.                    

   For further information on the structure of IPv6 addresses, refer to
   RFC3513.

  32.9.2. Configuring IPv6

   To configure a FreeBSD system as an IPv6 client, add these two lines to
   rc.conf:

 ifconfig_rl0_ipv6="inet6 accept_rtadv"
 rtsold_enable="YES"

   The first line enables the specified interface to receive router
   advertisement messages. The second line enables the router solicitation
   daemon, rtsol(8).

   If the interface needs a statically assigned IPv6 address, add an entry to
   specify the static address and associated prefix length:

 ifconfig_rl0_ipv6="inet6 2001:db8:4672:6565:2026:5043:2d42:5344 prefixlen 64"

   To assign a default router, specify its address:

 ipv6_defaultrouter="2001:db8:4672:6565::1"

  32.9.3. Connecting to a Provider

   In order to connect to other IPv6 networks, one must have a provider or a
   tunnel that supports IPv6:

     * Contact an Internet Service Provider to see if they offer IPv6.

     * Hurricane Electric offers tunnels with end-points all around the
       globe.

  Note:

   Install the net/freenet6 package or port for a dial-up connection.

   This section demonstrates how to take the directions from a tunnel
   provider and convert them into /etc/rc.conf settings that will persist
   through reboots.

   The first /etc/rc.conf entry creates the generic tunneling interface gif0:

 cloned_interfaces="gif0"

   Next, configure that interface with the IPv4 addresses of the local and
   remote endpoints. Replace MY_IPv4_ADDR and REMOTE_IPv4_ADDR with the
   actual IPv4 addresses:

 create_args_gif0="tunnel MY_IPv4_ADDR REMOTE_IPv4_ADDR"

   To apply the IPv6 address that has been assigned for use as the IPv6
   tunnel endpoint, add this line, replacing
   MY_ASSIGNED_IPv6_TUNNEL_ENDPOINT_ADDR with the assigned address:

 ifconfig_gif0_ipv6="inet6 MY_ASSIGNED_IPv6_TUNNEL_ENDPOINT_ADDR"

   Then, set the default route for the other side of the IPv6 tunnel. Replace
   MY_IPv6_REMOTE_TUNNEL_ENDPOINT_ADDR with the default gateway address
   assigned by the provider:

 ipv6_defaultrouter="MY_IPv6_REMOTE_TUNNEL_ENDPOINT_ADDR"

   If the FreeBSD system will route IPv6 packets between the rest of the
   network and the world, enable the gateway using this line:

 ipv6_gateway_enable="YES"

  32.9.4. Router Advertisement and Host Auto Configuration

   This section demonstrates how to setup rtadvd(8) to advertise the IPv6
   default route.

   To enable rtadvd(8), add the following to /etc/rc.conf:

 rtadvd_enable="YES"

   It is important to specify the interface on which to do IPv6 router
   advertisement. For example, to tell rtadvd(8) to use rl0:

 rtadvd_interfaces="rl0"

   Next, create the configuration file, /etc/rtadvd.conf as seen in this
   example:

 rl0:\
         :addrs#1:addr="2001:db8:1f11:246::":prefixlen#64:tc=ether:

   Replace rl0 with the interface to be used and 2001:db8:1f11:246:: with the
   prefix of the allocation.

   For a dedicated /64 subnet, nothing else needs to be changed. Otherwise,
   change the prefixlen# to the correct value.

  32.9.5. IPv6 and IPv6 Address Mapping

   When IPv6 is enabled on a server, there may be a need to enable IPv4
   mapped IPv6 address communication. This compatibility option allows for
   IPv4 addresses to be represented as IPv6 addresses. Permitting IPv6
   applications to communicate with IPv4 and vice versa may be a security
   issue.

   This option may not be required in most cases and is available only for
   compatibility. This option will allow IPv6-only applications to work with
   IPv4 in a dual stack environment. This is most useful for third party
   applications which may not support an IPv6-only environment. To enable
   this feature, add the following to /etc/rc.conf:

 ipv6_ipv4mapping="YES"

   Reviewing the information in RFC 3493, section 3.6 and 3.7 as well as RFC
   4038 section 4.2 may be useful to some administrators.

32.10. Common Address Redundancy Protocol (CARP)

   Contributed by Tom Rhodes.
   Updated by Allan Jude.

   The Common Address Redundancy Protocol (CARP) allows multiple hosts to
   share the same IP address and Virtual Host ID (VHID) in order to provide
   high availability for one or more services. This means that one or more
   hosts can fail, and the other hosts will transparently take over so that
   users do not see a service failure.

   In addition to the shared IP address, each host has its own IP address for
   management and configuration. All of the machines that share an IP address
   have the same VHID. The VHID for each virtual IP address must be unique
   across the broadcast domain of the network interface.

   High availability using CARP is built into FreeBSD, though the steps to
   configure it vary slightly depending upon the FreeBSD version. This
   section provides the same example configuration for versions before and
   equal to or after FreeBSD 10.

   This example configures failover support with three hosts, all with unique
   IP addresses, but providing the same web content. It has two different
   masters named hosta.example.org and hostb.example.org, with a shared
   backup named hostc.example.org.

   These machines are load balanced with a Round Robin DNS configuration. The
   master and backup machines are configured identically except for their
   hostnames and management IP addresses. These servers must have the same
   configuration and run the same services. When the failover occurs,
   requests to the service on the shared IP address can only be answered
   correctly if the backup server has access to the same content. The backup
   machine has two additional CARP interfaces, one for each of the master
   content server's IP addresses. When a failure occurs, the backup server
   will pick up the failed master machine's IP address.

  32.10.1. Using CARP on FreeBSD 10 and Later

   Enable boot-time support for CARP by adding an entry for the carp.ko
   kernel module in /boot/loader.conf:

 carp_load="YES"

   To load the module now without rebooting:

 # kldload carp

   For users who prefer to use a custom kernel, include the following line in
   the custom kernel configuration file and compile the kernel as described
   in Chapter 8, Configuring the FreeBSD Kernel:

 device  carp

   The hostname, management IP address and subnet mask, shared IP address,
   and VHID are all set by adding entries to /etc/rc.conf. This example is
   for hosta.example.org:

 hostname="hosta.example.org"
 ifconfig_em0="inet 192.168.1.3 netmask 255.255.255.0"
 ifconfig_em0_alias0="inet vhid 1 pass testpass alias 192.168.1.50/32"

   The next set of entries are for hostb.example.org. Since it represents a
   second master, it uses a different shared IP address and VHID. However,
   the passwords specified with pass must be identical as CARP will only
   listen to and accept advertisements from machines with the correct
   password.

 hostname="hostb.example.org"
 ifconfig_em0="inet 192.168.1.4 netmask 255.255.255.0"
 ifconfig_em0_alias0="inet vhid 2 pass testpass alias 192.168.1.51/32"

   The third machine, hostc.example.org, is configured to handle failover
   from either master. This machine is configured with two CARP VHIDs, one to
   handle the virtual IP address for each of the master hosts. The CARP
   advertising skew, advskew, is set to ensure that the backup host
   advertises later than the master, since advskew controls the order of
   precedence when there are multiple backup servers.

 hostname="hostc.example.org"
 ifconfig_em0="inet 192.168.1.5 netmask 255.255.255.0"
 ifconfig_em0_alias0="inet vhid 1 advskew 100 pass testpass alias 192.168.1.50/32"
 ifconfig_em0_alias1="inet vhid 2 advskew 100 pass testpass alias 192.168.1.51/32"

   Having two CARP VHIDs configured means that hostc.example.org will notice
   if either of the master servers becomes unavailable. If a master fails to
   advertise before the backup server, the backup server will pick up the
   shared IP address until the master becomes available again.

  Note:

   If the original master server becomes available again, hostc.example.org
   will not release the virtual IP address back to it automatically. For this
   to happen, preemption has to be enabled. The feature is disabled by
   default, it is controlled via the sysctl(8) variable
   net.inet.carp.preempt. The administrator can force the backup server to
   return the IP address to the master:

 # ifconfig em0 vhid 1 state backup

   Once the configuration is complete, either restart networking or reboot
   each system. High availability is now enabled.

   CARP functionality can be controlled via several sysctl(8) variables
   documented in the carp(4) manual pages. Other actions can be triggered
   from CARP events by using devd(8).

  32.10.2. Using CARP on FreeBSD 9 and Earlier

   The configuration for these versions of FreeBSD is similar to the one
   described in the previous section, except that a CARP device must first be
   created and referred to in the configuration.

   Enable boot-time support for CARP by loading the if_carp.ko kernel module
   in /boot/loader.conf:

 if_carp_load="YES"

   To load the module now without rebooting:

 # kldload carp

   For users who prefer to use a custom kernel, include the following line in
   the custom kernel configuration file and compile the kernel as described
   in Chapter 8, Configuring the FreeBSD Kernel:

 device  carp

   Next, on each host, create a CARP device:

 # ifconfig carp0 create

   Set the hostname, management IP address, the shared IP address, and VHID
   by adding the required lines to /etc/rc.conf. Since a virtual CARP device
   is used instead of an alias, the actual subnet mask of /24 is used instead
   of /32. Here are the entries for hosta.example.org:

 hostname="hosta.example.org"
 ifconfig_fxp0="inet 192.168.1.3 netmask 255.255.255.0"
 cloned_interfaces="carp0"
 ifconfig_carp0="vhid 1 pass testpass 192.168.1.50/24"

   On hostb.example.org:

 hostname="hostb.example.org"
 ifconfig_fxp0="inet 192.168.1.4 netmask 255.255.255.0"
 cloned_interfaces="carp0"
 ifconfig_carp0="vhid 2 pass testpass 192.168.1.51/24"

   The third machine, hostc.example.org, is configured to handle failover
   from either of the master hosts:

 hostname="hostc.example.org"
 ifconfig_fxp0="inet 192.168.1.5 netmask 255.255.255.0"
 cloned_interfaces="carp0 carp1"
 ifconfig_carp0="vhid 1 advskew 100 pass testpass 192.168.1.50/24"
 ifconfig_carp1="vhid 2 advskew 100 pass testpass 192.168.1.51/24"

  Note:

   Preemption is disabled in the GENERIC FreeBSD kernel. If preemption has
   been enabled with a custom kernel, hostc.example.org may not release the
   IP address back to the original content server. The administrator can
   force the backup server to return the IP address to the master with the
   command:

 # ifconfig carp0 down && ifconfig carp0 up

   This should be done on the carp interface which corresponds to the correct
   host.

   Once the configuration is complete, either restart networking or reboot
   each system. High availability is now enabled.

32.11. VLANs

   VLANs are a way of virtually dividing up a network into many different
   subnetworks, also referred to as segmenting. Each segment will have its
   own broadcast domain and be isolated from other VLANs.

   On FreeBSD, VLANs must be supported by the network card driver. To see
   which drivers support vlans, refer to the vlan(4) manual page.

   When configuring a VLAN, a couple pieces of information must be known.
   First, which network interface? Second, what is the VLAN tag?

   To configure VLANs at run time, with a NIC of em0 and a VLAN tag of 5 the
   command would look like this:

 # ifconfig em0.5 create vlan 5 vlandev em0 inet 192.168.20.20/24

  Note:

   See how the interface name includes the NIC driver name and the VLAN tag,
   separated by a period? This is a best practice to make maintaining the
   VLAN configuration easy when many VLANs are present on a machine.

   To configure VLANs at boot time, /etc/rc.conf must be updated. To
   duplicate the configuration above, the following will need to be added:

 vlans_em0="5"
 ifconfig_em0_5="inet 192.168.20.20/24"

   Additional VLANs may be added, by simply adding the tag to the vlans_em0
   field and adding an additional line configuring the network on that VLAN
   tag's interface.

   It is useful to assign a symbolic name to an interface so that when the
   associated hardware is changed, only a few configuration variables need to
   be updated. For example, security cameras need to be run over VLAN 1 on
   em0. Later, if the em0 card is replaced with a card that uses the ixgb(4)
   driver, all references to em0.1 will not have to change to ixgb0.1.

   To configure VLAN 5, on the NIC em0, assign the interface name cameras,
   and assign the interface an IP address of 192.168.20.20 with a 24-bit
   prefix, use this command:

 # ifconfig em0.5 create vlan 5 vlandev em0 name cameras inet 192.168.20.20/24

   For an interface named video, use the following:

 # ifconfig video.5 create vlan 5 vlandev video name cameras inet 192.168.20.20/24

   To apply the changes at boot time, add the following lines to
   /etc/rc.conf:

 vlans_video="cameras"
 create_args_cameras="vlan 5"
 ifconfig_cameras="inet 192.168.20.20/24"

                               Part V. Appendices

   Table of Contents

   A. Obtaining FreeBSD

                A.1. CD and DVD Sets

                A.2. FTP Sites

                A.3. Using Subversion

                A.4. Using rsync

   B. Bibliography

                B.1. Books Specific to FreeBSD

                B.2. Users' Guides

                B.3. Administrators' Guides

                B.4. Programmers' Guides

                B.5. Operating System Internals

                B.6. Security Reference

                B.7. Hardware Reference

                B.8. UNIX(R) History

                B.9. Periodicals, Journals, and Magazines

   C. Resources on the Internet

                C.1. Websites

                C.2. Mailing Lists

                C.3. Usenet Newsgroups

                C.4. Official Mirrors

   D. OpenPGP Keys

                D.1. Officers

Appendix A. Obtaining FreeBSD

   Table of Contents

   A.1. CD and DVD Sets

   A.2. FTP Sites

   A.3. Using Subversion

   A.4. Using rsync

A.1. CD and DVD Sets

   FreeBSD CD and DVD sets are available from several online retailers:

     * FreeBSD Mall, Inc.
         2420 Sand Creek Rd C-1 #347
         Brentwood, CA
         94513
         USA
         Phone: +1 925 240-6652
         Fax: +1 925 674-0821
         Email: <info@freebsdmall.com>
         WWW: https://www.freebsdmall.com

     * Getlinux
         78 Rue de la Croix Rochopt
         Epinay-sous-Senart
         91860
         France
         Email: <contact@getlinux.fr>
         WWW: http://www.getlinux.fr/

     * Dr. Hinner EDV
         Kochelseestr. 11
         D-81371 Mu:nchen
         Germany
         Phone: (0177) 428 419 0
         Email: <infow@hinner.de>
         WWW: http://www.hinner.de/linux/freebsd.html

     * Linux Center
         Galernaya Street, 55
         Saint-Petersburg
         190000
         Russia
         Phone: +7-812-309-06-86
         Email: <info@linuxcenter.ru>
         WWW: http://linuxcenter.ru/shop/freebsd

A.2. FTP Sites

   The official sources for FreeBSD are available via anonymous FTP from a
   worldwide set of mirror sites. The site ftp://ftp.FreeBSD.org/pub/FreeBSD/
   is available via HTTP and FTP. It is made up of many machines operated by
   the project cluster administrators and behind GeoDNS to direct users to
   the closest available mirror.

   Additionally, FreeBSD is available via anonymous FTP from the following
   mirror sites. When obtaining FreeBSD via anonymous FTP, please try to use
   a nearby site. The mirror sites listed as "Primary Mirror Sites" typically
   have the entire FreeBSD archive (all the currently available versions for
   each of the architectures) but faster download speeds are probably
   available from a site that is in your country or region. The regional
   sites carry the most recent versions for the most popular architecture(s)
   but might not carry the entire FreeBSD archive. All sites provide access
   via anonymous FTP but some sites also provide access via other methods.
   The access methods available for each site are provided in parentheses
   after the hostname.

   Central Servers, Primary Mirror Sites, Armenia, Australia, Austria,
   Brazil, Czech Republic, Denmark, Estonia, Finland, France, Germany,
   Greece, Hong Kong, Ireland, Japan, Korea, Latvia, Lithuania, Netherlands,
   New Zealand, Norway, Poland, Russia, Saudi Arabia, Slovenia, South Africa,
   Spain, Sweden, Switzerland, Taiwan, Ukraine, United Kingdom, USA.

   (as of UTC)

   Central Servers
              * ftp://ftp.FreeBSD.org/pub/FreeBSD/ (ftp / ftpv6 /
                http://ftp.FreeBSD.org/pub/FreeBSD/ /
                http://ftp.FreeBSD.org/pub/FreeBSD/)

   Primary Mirror Sites

           In case of problems, please contact the hostmaster
           <mirror-admin@FreeBSD.org> for this domain.

              * ftp://ftp1.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp2.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp3.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp4.FreeBSD.org/pub/FreeBSD/ (ftp / ftpv6 /
                http://ftp4.FreeBSD.org/pub/FreeBSD/ /
                http://ftp4.FreeBSD.org/pub/FreeBSD/)

              * ftp://ftp5.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp6.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp7.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp10.FreeBSD.org/pub/FreeBSD/ (ftp / ftpv6 /
                http://ftp10.FreeBSD.org/pub/FreeBSD/ /
                http://ftp10.FreeBSD.org/pub/FreeBSD/)

              * ftp://ftp11.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp13.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp14.FreeBSD.org/pub/FreeBSD/ (ftp /
                http://ftp14.FreeBSD.org/pub/FreeBSD/)

   Armenia

           In case of problems, please contact the hostmaster
           <hostmaster@am.FreeBSD.org> for this domain.

              * ftp://ftp1.am.FreeBSD.org/pub/FreeBSD/ (ftp /
                http://ftp1.am.FreeBSD.org/pub/FreeBSD/ / rsync)

   Australia

           In case of problems, please contact the hostmaster
           <hostmaster@au.FreeBSD.org> for this domain.

              * ftp://ftp.au.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp2.au.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp3.au.FreeBSD.org/pub/FreeBSD/ (ftp)

   Austria

           In case of problems, please contact the hostmaster
           <hostmaster@at.FreeBSD.org> for this domain.

              * ftp://ftp.at.FreeBSD.org/pub/FreeBSD/ (ftp / ftpv6 /
                http://ftp.at.FreeBSD.org/pub/FreeBSD/ /
                http://ftp.at.FreeBSD.org/pub/FreeBSD/)

   Brazil

           In case of problems, please contact the hostmaster
           <hostmaster@br.FreeBSD.org> for this domain.

              * ftp://ftp2.br.FreeBSD.org/FreeBSD/ (ftp /
                http://ftp2.br.FreeBSD.org/)

              * ftp://ftp3.br.FreeBSD.org/pub/FreeBSD/ (ftp / rsync)

              * ftp://ftp4.br.FreeBSD.org/pub/FreeBSD/ (ftp)

   Czech Republic

           In case of problems, please contact the hostmaster
           <hostmaster@cz.FreeBSD.org> for this domain.

              * ftp://ftp.cz.FreeBSD.org/pub/FreeBSD/ (ftp /
                ftp://ftp.cz.FreeBSD.org/pub/FreeBSD/ /
                http://ftp.cz.FreeBSD.org/pub/FreeBSD/ /
                http://ftp.cz.FreeBSD.org/pub/FreeBSD/ / rsync / rsyncv6)

              * ftp://ftp2.cz.FreeBSD.org/pub/FreeBSD/ (ftp /
                http://ftp2.cz.FreeBSD.org/pub/FreeBSD/)

   Denmark

           In case of problems, please contact the hostmaster
           <hostmaster@dk.FreeBSD.org> for this domain.

              * ftp://ftp.dk.FreeBSD.org/pub/FreeBSD/ (ftp / ftpv6 /
                http://ftp.dk.FreeBSD.org/pub/FreeBSD/ /
                http://ftp.dk.FreeBSD.org/pub/FreeBSD/)

   Estonia

           In case of problems, please contact the hostmaster
           <hostmaster@ee.FreeBSD.org> for this domain.

              * ftp://ftp.ee.FreeBSD.org/pub/FreeBSD/ (ftp)

   Finland

           In case of problems, please contact the hostmaster
           <hostmaster@fi.FreeBSD.org> for this domain.

              * ftp://ftp.fi.FreeBSD.org/pub/FreeBSD/ (ftp)

   France

           In case of problems, please contact the hostmaster
           <hostmaster@fr.FreeBSD.org> for this domain.

              * ftp://ftp.fr.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp1.fr.FreeBSD.org/pub/FreeBSD/ (ftp /
                http://ftp1.fr.FreeBSD.org/pub/FreeBSD/ / rsync)

              * ftp://ftp3.fr.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp5.fr.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp6.fr.FreeBSD.org/pub/FreeBSD/ (ftp / rsync)

              * ftp://ftp7.fr.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp8.fr.FreeBSD.org/pub/FreeBSD/ (ftp)

   Germany

           In case of problems, please contact the hostmaster
           <de-bsd-hubs@de.FreeBSD.org> for this domain.

              * ftp://ftp.de.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp1.de.FreeBSD.org/freebsd/ (ftp /
                http://www1.de.FreeBSD.org/freebsd/ /
                rsync://rsync3.de.FreeBSD.org/freebsd/)

              * ftp://ftp2.de.FreeBSD.org/pub/FreeBSD/ (ftp /
                http://ftp2.de.FreeBSD.org/pub/FreeBSD/ / rsync)

              * ftp://ftp4.de.FreeBSD.org/FreeBSD/ (ftp /
                http://ftp4.de.FreeBSD.org/pub/FreeBSD/)

              * ftp://ftp5.de.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp7.de.FreeBSD.org/pub/FreeBSD/ (ftp /
                http://ftp7.de.FreeBSD.org/pub/FreeBSD/)

              * ftp://ftp8.de.FreeBSD.org/pub/FreeBSD/ (ftp)

   Greece

           In case of problems, please contact the hostmaster
           <hostmaster@gr.FreeBSD.org> for this domain.

              * ftp://ftp.gr.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp2.gr.FreeBSD.org/pub/FreeBSD/ (ftp)

   Hong Kong
              * ftp://ftp.hk.FreeBSD.org/pub/FreeBSD/ (ftp)

   Ireland

           In case of problems, please contact the hostmaster
           <hostmaster@ie.FreeBSD.org> for this domain.

              * ftp://ftp3.ie.FreeBSD.org/pub/FreeBSD/ (ftp / rsync)

   Japan

           In case of problems, please contact the hostmaster
           <hostmaster@jp.FreeBSD.org> for this domain.

              * ftp://ftp.jp.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp2.jp.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp3.jp.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp4.jp.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp5.jp.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp6.jp.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp7.jp.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp8.jp.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp9.jp.FreeBSD.org/pub/FreeBSD/ (ftp)

   Korea

           In case of problems, please contact the hostmaster
           <hostmaster@kr.FreeBSD.org> for this domain.

              * ftp://ftp.kr.FreeBSD.org/pub/FreeBSD/ (ftp / rsync)

              * ftp://ftp2.kr.FreeBSD.org/pub/FreeBSD/ (ftp /
                http://ftp2.kr.FreeBSD.org/pub/FreeBSD/)

   Latvia

           In case of problems, please contact the hostmaster
           <hostmaster@lv.FreeBSD.org> for this domain.

              * ftp://ftp.lv.FreeBSD.org/pub/FreeBSD/ (ftp /
                http://ftp.lv.FreeBSD.org/pub/FreeBSD/)

   Lithuania

           In case of problems, please contact the hostmaster
           <hostmaster@lt.FreeBSD.org> for this domain.

              * ftp://ftp.lt.FreeBSD.org/pub/FreeBSD/ (ftp /
                http://ftp.lt.FreeBSD.org/pub/FreeBSD/)

   Netherlands

           In case of problems, please contact the hostmaster
           <hostmaster@nl.FreeBSD.org> for this domain.

              * ftp://ftp.nl.FreeBSD.org/pub/FreeBSD/ (ftp /
                http://ftp.nl.FreeBSD.org/os/FreeBSD/ / rsync)

              * ftp://ftp2.nl.FreeBSD.org/pub/FreeBSD/ (ftp)

   New Zealand
              * ftp://ftp.nz.FreeBSD.org/pub/FreeBSD/ (ftp /
                http://ftp.nz.FreeBSD.org/pub/FreeBSD/)

   Norway

           In case of problems, please contact the hostmaster
           <hostmaster@no.FreeBSD.org> for this domain.

              * ftp://ftp.no.FreeBSD.org/pub/FreeBSD/ (ftp / rsync)

   Poland

           In case of problems, please contact the hostmaster
           <hostmaster@pl.FreeBSD.org> for this domain.

              * ftp://ftp.pl.FreeBSD.org/pub/FreeBSD/ (ftp)

   Russia

           In case of problems, please contact the hostmaster
           <hostmaster@ru.FreeBSD.org> for this domain.

              * ftp://ftp.ru.FreeBSD.org/pub/FreeBSD/ (ftp /
                http://ftp.ru.FreeBSD.org/FreeBSD/ / rsync)

              * ftp://ftp2.ru.FreeBSD.org/pub/FreeBSD/ (ftp /
                http://ftp2.ru.FreeBSD.org/pub/FreeBSD/ / rsync)

              * ftp://ftp4.ru.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp5.ru.FreeBSD.org/pub/FreeBSD/ (ftp /
                http://ftp5.ru.FreeBSD.org/pub/FreeBSD/ / rsync)

              * ftp://ftp6.ru.FreeBSD.org/pub/FreeBSD/ (ftp)

   Saudi Arabia

           In case of problems, please contact the hostmaster
           <ftpadmin@isu.net.sa> for this domain.

              * ftp://ftp.isu.net.sa/pub/ftp.freebsd.org/ (ftp)

   Slovenia

           In case of problems, please contact the hostmaster
           <hostmaster@si.FreeBSD.org> for this domain.

              * ftp://ftp.si.FreeBSD.org/pub/FreeBSD/ (ftp)

   South Africa

           In case of problems, please contact the hostmaster
           <hostmaster@za.FreeBSD.org> for this domain.

              * ftp://ftp.za.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp2.za.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp4.za.FreeBSD.org/pub/FreeBSD/ (ftp)

   Spain

           In case of problems, please contact the hostmaster
           <hostmaster@es.FreeBSD.org> for this domain.

              * ftp://ftp.es.FreeBSD.org/pub/FreeBSD/ (ftp /
                http://ftp.es.FreeBSD.org/pub/FreeBSD/)

              * ftp://ftp3.es.FreeBSD.org/pub/FreeBSD/ (ftp)

   Sweden

           In case of problems, please contact the hostmaster
           <hostmaster@se.FreeBSD.org> for this domain.

              * ftp://ftp.se.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp2.se.FreeBSD.org/pub/FreeBSD/ (ftp /
                rsync://ftp2.se.FreeBSD.org/)

              * ftp://ftp3.se.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp4.se.FreeBSD.org/pub/FreeBSD/ (ftp /
                ftp://ftp4.se.FreeBSD.org/pub/FreeBSD/ /
                http://ftp4.se.FreeBSD.org/pub/FreeBSD/ /
                http://ftp4.se.FreeBSD.org/pub/FreeBSD/ /
                rsync://ftp4.se.FreeBSD.org/pub/FreeBSD/ /
                rsync://ftp4.se.FreeBSD.org/pub/FreeBSD/)

              * ftp://ftp6.se.FreeBSD.org/pub/FreeBSD/ (ftp /
                http://ftp6.se.FreeBSD.org/pub/FreeBSD/)

   Switzerland

           In case of problems, please contact the hostmaster
           <hostmaster@ch.FreeBSD.org> for this domain.

              * ftp://ftp.ch.FreeBSD.org/pub/FreeBSD/ (ftp /
                http://ftp.ch.FreeBSD.org/pub/FreeBSD/)

   Taiwan

           In case of problems, please contact the hostmaster
           <hostmaster@tw.FreeBSD.org> for this domain.

              * ftp://ftp.tw.FreeBSD.org/pub/FreeBSD/ (ftp /
                ftp://ftp.tw.FreeBSD.org/pub/FreeBSD/ / rsync / rsyncv6)

              * ftp://ftp2.tw.FreeBSD.org/pub/FreeBSD/ (ftp /
                ftp://ftp2.tw.FreeBSD.org/pub/FreeBSD/ /
                http://ftp2.tw.FreeBSD.org/pub/FreeBSD/ /
                http://ftp2.tw.FreeBSD.org/pub/FreeBSD/ / rsync / rsyncv6)

              * ftp://ftp4.tw.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp5.tw.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp6.tw.FreeBSD.org/pub/FreeBSD/ (ftp /
                http://ftp6.tw.FreeBSD.org/ / rsync)

              * ftp://ftp7.tw.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp8.tw.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp11.tw.FreeBSD.org/pub/FreeBSD/ (ftp /
                http://ftp11.tw.FreeBSD.org/FreeBSD/)

              * ftp://ftp12.tw.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp13.tw.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp14.tw.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp15.tw.FreeBSD.org/pub/FreeBSD/ (ftp)

   Ukraine
              * ftp://ftp.ua.FreeBSD.org/pub/FreeBSD/ (ftp /
                http://ftp.ua.FreeBSD.org/pub/FreeBSD/)

              * ftp://ftp6.ua.FreeBSD.org/pub/FreeBSD/ (ftp /
                http://ftp6.ua.FreeBSD.org/pub/FreeBSD /
                rsync://ftp6.ua.FreeBSD.org/FreeBSD/)

              * ftp://ftp7.ua.FreeBSD.org/pub/FreeBSD/ (ftp)

   United Kingdom

           In case of problems, please contact the hostmaster
           <hostmaster@uk.FreeBSD.org> for this domain.

              * ftp://ftp.uk.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp2.uk.FreeBSD.org/pub/FreeBSD/ (ftp /
                rsync://ftp2.uk.FreeBSD.org/ftp.freebsd.org/pub/FreeBSD/)

              * ftp://ftp3.uk.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp4.uk.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp5.uk.FreeBSD.org/pub/FreeBSD/ (ftp)

   USA

           In case of problems, please contact the hostmaster
           <hostmaster@us.FreeBSD.org> for this domain.

              * ftp://ftp1.us.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp2.us.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp3.us.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp4.us.FreeBSD.org/pub/FreeBSD/ (ftp / ftpv6 /
                http://ftp4.us.FreeBSD.org/pub/FreeBSD/ /
                http://ftp4.us.FreeBSD.org/pub/FreeBSD/)

              * ftp://ftp5.us.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp6.us.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp8.us.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp10.us.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp11.us.FreeBSD.org/pub/FreeBSD/ (ftp)

              * ftp://ftp13.us.FreeBSD.org/pub/FreeBSD/ (ftp /
                http://ftp13.us.FreeBSD.org/pub/FreeBSD/ / rsync)

              * ftp://ftp14.us.FreeBSD.org/pub/FreeBSD/ (ftp /
                http://ftp14.us.FreeBSD.org/pub/FreeBSD/)

              * ftp://ftp15.us.FreeBSD.org/pub/FreeBSD/ (ftp)

A.3. Using Subversion

  A.3.1. Introduction

   As of July 2012, FreeBSD uses Subversion as the only version control
   system for storing all of FreeBSD's source code, documentation, and the
   Ports Collection.

  Note:

   Subversion is generally a developer tool. Users may prefer to use
   freebsd-update (Section 24.2, "FreeBSD Update") to update the FreeBSD base
   system, and portsnap (Section 4.5, "Using the Ports Collection") to update
   the FreeBSD Ports Collection.

   This section demonstrates how to install Subversion on a FreeBSD system
   and use it to create a local copy of a FreeBSD repository. Additional
   information on the use of Subversion is included.

  A.3.2. Root SSL Certificates

   Installing security/ca_root_nss allows Subversion to verify the identity
   of HTTPS repository servers. The root SSL certificates can be installed
   from a port:

 # cd /usr/ports/security/ca_root_nss
 # make install clean

   or as a package:

 # pkg install ca_root_nss

  A.3.3. Svnlite

   A lightweight version of Subversion is already installed on FreeBSD as
   svnlite. The port or package version of Subversion is only needed if the
   Python or Perl API is needed, or if a later version of Subversion is
   desired.

   The only difference from normal Subversion use is that the command name is
   svnlite.

  A.3.4. Installation

   If svnlite is unavailable or the full version of Subversion is needed,
   then it must be installed.

   Subversion can be installed from the Ports Collection:

 # cd /usr/ports/devel/subversion
 # make install clean

   Subversion can also be installed as a package:

 # pkg install subversion

  A.3.5. Running Subversion

   To fetch a clean copy of the sources into a local directory, use svn. The
   files in this directory are called a local working copy.

  Warning:

   Move or delete an existing destination directory before using checkout for
   the first time.

   Checkout over an existing non-svn directory can cause conflicts between
   the existing files and those brought in from the repository.

   Subversion uses URLs to designate a repository, taking the form of
   protocol://hostname/path. The first component of the path is the FreeBSD
   repository to access. There are three different repositories, base for the
   FreeBSD base system source code, ports for the Ports Collection, and doc
   for documentation. For example, the URL
   https://svn.FreeBSD.org/ports/head/ specifies the main branch of the ports
   repository, using the https protocol.

   A checkout from a given repository is performed with a command like this:

 # svn checkout https://svn.FreeBSD.org/repository/branch lwcdir

   where:

     * repository is one of the Project repositories: base, ports, or doc.

     * branch depends on the repository used. ports and doc are mostly
       updated in the head branch, while base maintains the latest version of
       -CURRENT under head and the respective latest versions of the -STABLE
       branches under stable/9 (9.x) and stable/10 (10.x).

     * lwcdir is the target directory where the contents of the specified
       branch should be placed. This is usually /usr/ports for ports,
       /usr/src for base, and /usr/doc for doc.

   This example checks out the Ports Collection from the FreeBSD repository
   using the HTTPS protocol, placing the local working copy in /usr/ports. If
   /usr/ports is already present but was not created by svn, remember to
   rename or delete it before the checkout.

 # svn checkout https://svn.FreeBSD.org/ports/head /usr/ports

   Because the initial checkout must download the full branch of the remote
   repository, it can take a while. Please be patient.

   After the initial checkout, the local working copy can be updated by
   running:

 # svn update lwcdir

   To update /usr/ports created in the example above, use:

 # svn update /usr/ports

   The update is much quicker than a checkout, only transferring files that
   have changed.

   An alternate way of updating the local working copy after checkout is
   provided by the Makefile in the /usr/ports, /usr/src, and /usr/doc
   directories. Set SVN_UPDATE and use the update target. For example, to
   update /usr/src:

 # cd /usr/src
 # make update SVN_UPDATE=yes

  A.3.6. Subversion Mirror Sites

   The FreeBSD Subversion repository is:

 svn.FreeBSD.org

   This is a publicly accessible mirror network that uses GeoDNS to select an
   appropriate back end server. To view the FreeBSD Subversion repositories
   through a browser, use https://svnweb.FreeBSD.org/.

   HTTPS is the preferred protocol, but the security/ca_root_nss package will
   need to be installed in order to automatically validate certificates.

  A.3.7. For More Information

   For other information about using Subversion, please see the "Subversion
   Book", titled Version Control with Subversion, or the Subversion
   Documentation.

A.4. Using rsync

   These sites make FreeBSD available through the rsync protocol. The rsync
   utility transfers only the differences between two sets of files. This is
   useful for mirror sites of the FreeBSD FTP server. The rsync suite is
   available for many operating systems, on FreeBSD, see the net/rsync port
   or use the package.

   Czech Republic

           rsync://ftp.cz.FreeBSD.org/

           Available collections:

              * ftp: A partial mirror of the FreeBSD FTP server.

              * FreeBSD: A full mirror of the FreeBSD FTP server.

   Netherlands

           rsync://ftp.nl.FreeBSD.org/

           Available collections:

              * FreeBSD: A full mirror of the FreeBSD FTP server.

   Russia

           rsync://ftp.mtu.ru/

           Available collections:

              * FreeBSD: A full mirror of the FreeBSD FTP server.

              * FreeBSD-Archive: The mirror of FreeBSD Archive FTP server.

   Sweden

           rsync://ftp4.se.freebsd.org/

           Available collections:

              * FreeBSD: A full mirror of the FreeBSD FTP server.

   Taiwan

           rsync://ftp.tw.FreeBSD.org/

           rsync://ftp2.tw.FreeBSD.org/

           rsync://ftp6.tw.FreeBSD.org/

           Available collections:

              * FreeBSD: A full mirror of the FreeBSD FTP server.

   United Kingdom

           rsync://rsync.mirrorservice.org/

           Available collections:

              * ftp.freebsd.org: A full mirror of the FreeBSD FTP server.

   United States of America

           rsync://ftp-master.FreeBSD.org/

           This server may only be used by FreeBSD primary mirror sites.

           Available collections:

              * FreeBSD: The master archive of the FreeBSD FTP server.

              * acl: The FreeBSD master ACL list.

           rsync://ftp13.FreeBSD.org/

           Available collections:

              * FreeBSD: A full mirror of the FreeBSD FTP server.

Appendix B. Bibliography

   Table of Contents

   B.1. Books Specific to FreeBSD

   B.2. Users' Guides

   B.3. Administrators' Guides

   B.4. Programmers' Guides

   B.5. Operating System Internals

   B.6. Security Reference

   B.7. Hardware Reference

   B.8. UNIX(R) History

   B.9. Periodicals, Journals, and Magazines

   While manual pages provide a definitive reference for individual pieces of
   the FreeBSD operating system, they seldom illustrate how to put the pieces
   together to make the whole operating system run smoothly. For this, there
   is no substitute for a good book or users' manual on UNIX(R) system
   administration.

B.1. Books Specific to FreeBSD

   International books:

     * Using FreeBSD (in Traditional Chinese), published by Drmaster, 1997.
       ISBN 9-578-39435-7.

     * FreeBSD Unleashed (Simplified Chinese translation), published by China
       Machine Press. ISBN 7-111-10201-0.

     * FreeBSD From Scratch Second Edition (in Simplified Chinese), published
       by China Machine Press. ISBN 7-111-10286-X.

     * FreeBSD Handbook Second Edition (Simplified Chinese translation),
       published by Posts & Telecom Press. ISBN 7-115-10541-3.

     * FreeBSD & Windows (in Simplified Chinese), published by China Railway
       Publishing House. ISBN 7-113-03845-X

     * FreeBSD Internet Services HOWTO (in Simplified Chinese), published by
       China Railway Publishing House. ISBN 7-113-03423-3

     * FreeBSD (in Japanese), published by CUTT. ISBN 4-906391-22-2 C3055
       P2400E.

     * Complete Introduction to FreeBSD (in Japanese), published by Shoeisha
       Co., Ltd. ISBN 4-88135-473-6 P3600E.

     * Personal UNIX Starter Kit FreeBSD (in Japanese), published by ASCII.
       ISBN 4-7561-1733-3 P3000E.

     * FreeBSD Handbook (Japanese translation), published by ASCII. ISBN
       4-7561-1580-2 P3800E.

     * FreeBSD mit Methode (in German), published by Computer und Literatur
       Verlag/Vertrieb Hanser, 1998. ISBN 3-932311-31-0.

     * FreeBSD de Luxe (in German), published by Verlag Modere Industrie,
       2003. ISBN 3-8266-1343-0.

     * FreeBSD Install and Utilization Manual (in Japanese), published by
       Mainichi Communications Inc., 1998. ISBN 4-8399-0112-0.

     * Onno W Purbo, Dodi Maryanto, Syahrial Hubbany, Widjil Widodo Building
       Internet Server with FreeBSD (in Indonesia Language), published by
       Elex Media Komputindo.

     * Absolute BSD: The Ultimate Guide to FreeBSD (Traditional Chinese
       translation), published by GrandTech Press, 2003. ISBN 986-7944-92-5.

     * The FreeBSD 6.0 Book (in Traditional Chinese), published by Drmaster,
       2006. ISBN 9-575-27878-X.

   English language books:

     * Absolute FreeBSD, 2nd Edition: The Complete Guide to FreeBSD,
       published by No Starch Press, 2007. ISBN: 978-1-59327-151-0

     * The Complete FreeBSD, published by O'Reilly, 2003. ISBN: 0596005164

     * The FreeBSD Corporate Networker's Guide, published by Addison-Wesley,
       2000. ISBN: 0201704811

     * FreeBSD: An Open-Source Operating System for Your Personal Computer,
       published by The Bit Tree Press, 2001. ISBN: 0971204500

     * Teach Yourself FreeBSD in 24 Hours, published by Sams, 2002. ISBN:
       0672324245

     * FreeBSD 6 Unleashed, published by Sams, 2006. ISBN: 0672328755

     * FreeBSD: The Complete Reference, published by McGrawHill, 2003. ISBN:
       0072224096

B.2. Users' Guides

     * Ohio State University has written a UNIX Introductory Course which is
       available online in HTML and PostScript format.

       An Italian translation of this document is available as part of the
       FreeBSD Italian Documentation Project.

     * Jpman Project, Japan FreeBSD Users Group. FreeBSD User's Reference
       Manual (Japanese translation). Mainichi Communications Inc., 1998.
       ISBN4-8399-0088-4 P3800E.

     * Edinburgh University has written an Online Guide for newcomers to the
       UNIX environment.

B.3. Administrators' Guides

     * Jpman Project, Japan FreeBSD Users Group. FreeBSD System
       Administrator's Manual (Japanese translation). Mainichi Communications
       Inc., 1998. ISBN4-8399-0109-0 P3300E.

     * Dreyfus, Emmanuel. Cahiers de l'Admin: BSD 2nd Ed. (in French),
       Eyrolles, 2004. ISBN 2-212-11463-X

B.4. Programmers' Guides

     * Computer Systems Research Group, UC Berkeley. 4.4BSD Programmer's
       Reference Manual. O'Reilly & Associates, Inc., 1994. ISBN
       1-56592-078-3

     * Computer Systems Research Group, UC Berkeley. 4.4BSD Programmer's
       Supplementary Documents. O'Reilly & Associates, Inc., 1994. ISBN
       1-56592-079-1

     * Harbison, Samuel P. and Steele, Guy L. Jr. C: A Reference Manual. 4th
       Ed. Prentice Hall, 1995. ISBN 0-13-326224-3

     * Kernighan, Brian and Dennis M. Ritchie. The C Programming Language.
       2nd Ed. PTR Prentice Hall, 1988. ISBN 0-13-110362-8

     * Lehey, Greg. Porting UNIX Software. O'Reilly & Associates, Inc., 1995.
       ISBN 1-56592-126-7

     * Plauger, P. J. The Standard C Library. Prentice Hall, 1992. ISBN
       0-13-131509-9

     * Spinellis, Diomidis. Code Reading: The Open Source Perspective.
       Addison-Wesley, 2003. ISBN 0-201-79940-5

     * Spinellis, Diomidis. Code Quality: The Open Source Perspective.
       Addison-Wesley, 2006. ISBN 0-321-16607-8

     * Stevens, W. Richard and Stephen A. Rago. Advanced Programming in the
       UNIX Environment. 2nd Ed. Reading, Mass. : Addison-Wesley, 2005. ISBN
       0-201-43307-9

     * Stevens, W. Richard. UNIX Network Programming. 2nd Ed, PTR Prentice
       Hall, 1998. ISBN 0-13-490012-X

B.5. Operating System Internals

     * Andleigh, Prabhat K. UNIX System Architecture. Prentice-Hall, Inc.,
       1990. ISBN 0-13-949843-5

     * Jolitz, William. "Porting UNIX to the 386". Dr. Dobb's Journal.
       January 1991-July 1992.

     * Leffler, Samuel J., Marshall Kirk McKusick, Michael J Karels and John
       Quarterman The Design and Implementation of the 4.3BSD UNIX Operating
       System. Reading, Mass. : Addison-Wesley, 1989. ISBN 0-201-06196-1

     * Leffler, Samuel J., Marshall Kirk McKusick, The Design and
       Implementation of the 4.3BSD UNIX Operating System: Answer Book.
       Reading, Mass. : Addison-Wesley, 1991. ISBN 0-201-54629-9

     * McKusick, Marshall Kirk, Keith Bostic, Michael J Karels, and John
       Quarterman. The Design and Implementation of the 4.4BSD Operating
       System. Reading, Mass. : Addison-Wesley, 1996. ISBN 0-201-54979-4

       (Chapter 2 of this book is available online as part of the FreeBSD
       Documentation Project.)

     * Marshall Kirk McKusick, George V. Neville-Neil The Design and
       Implementation of the FreeBSD Operating System. Boston, Mass. :
       Addison-Wesley, 2004. ISBN 0-201-70245-2

     * Marshall Kirk McKusick, George V. Neville-Neil, Robert N. M. Watson
       The Design and Implementation of the FreeBSD Operating System, 2nd
       Ed.. Westford, Mass. : Pearson Education, Inc., 2014. ISBN
       0-321-96897-2

     * Stevens, W. Richard. TCP/IP Illustrated, Volume 1: The Protocols.
       Reading, Mass. : Addison-Wesley, 1996. ISBN 0-201-63346-9

     * Schimmel, Curt. Unix Systems for Modern Architectures. Reading, Mass.
       : Addison-Wesley, 1994. ISBN 0-201-63338-8

     * Stevens, W. Richard. TCP/IP Illustrated, Volume 3: TCP for
       Transactions, HTTP, NNTP and the UNIX Domain Protocols. Reading, Mass.
       : Addison-Wesley, 1996. ISBN 0-201-63495-3

     * Vahalia, Uresh. UNIX Internals -- The New Frontiers. Prentice Hall,
       1996. ISBN 0-13-101908-2

     * Wright, Gary R. and W. Richard Stevens. TCP/IP Illustrated, Volume 2:
       The Implementation. Reading, Mass. : Addison-Wesley, 1995. ISBN
       0-201-63354-X

B.6. Security Reference

     * Cheswick, William R. and Steven M. Bellovin. Firewalls and Internet
       Security: Repelling the Wily Hacker. Reading, Mass. : Addison-Wesley,
       1995. ISBN 0-201-63357-4

     * Garfinkel, Simson. PGP Pretty Good Privacy O'Reilly & Associates,
       Inc., 1995. ISBN 1-56592-098-8

B.7. Hardware Reference

     * Anderson, Don and Tom Shanley. Pentium Processor System Architecture.
       2nd Ed. Reading, Mass. : Addison-Wesley, 1995. ISBN 0-201-40992-5

     * Ferraro, Richard F. Programmer's Guide to the EGA, VGA, and Super VGA
       Cards. 3rd ed. Reading, Mass. : Addison-Wesley, 1995. ISBN
       0-201-62490-7

     * Intel Corporation publishes documentation on their CPUs, chipsets and
       standards on their developer web site, usually as PDF files.

     * Shanley, Tom. 80486 System Architecture. 3rd Ed. Reading, Mass. :
       Addison-Wesley, 1995. ISBN 0-201-40994-1

     * Shanley, Tom. ISA System Architecture. 3rd Ed. Reading, Mass. :
       Addison-Wesley, 1995. ISBN 0-201-40996-8

     * Shanley, Tom. PCI System Architecture. 4th Ed. Reading, Mass. :
       Addison-Wesley, 1999. ISBN 0-201-30974-2

     * Van Gilluwe, Frank. The Undocumented PC, 2nd Ed. Reading, Mass:
       Addison-Wesley Pub. Co., 1996. ISBN 0-201-47950-8

     * Messmer, Hans-Peter. The Indispensable PC Hardware Book, 4th Ed.
       Reading, Mass : Addison-Wesley Pub. Co., 2002. ISBN 0-201-59616-4

B.8. UNIX(R) History

     * Lion, John Lion's Commentary on UNIX, 6th Ed. With Source Code. ITP
       Media Group, 1996. ISBN 1573980137

     * Raymond, Eric S. The New Hacker's Dictionary, 3rd edition. MIT Press,
       1996. ISBN 0-262-68092-0. Also known as the Jargon File

     * Salus, Peter H. A quarter century of UNIX. Addison-Wesley Publishing
       Company, Inc., 1994. ISBN 0-201-54777-5

     * Simon Garfinkel, Daniel Weise, Steven Strassmann. The UNIX-HATERS
       Handbook. IDG Books Worldwide, Inc., 1994. ISBN 1-56884-203-1. Out of
       print, but available online.

     * Don Libes, Sandy Ressler Life with UNIX - special edition.
       Prentice-Hall, Inc., 1989. ISBN 0-13-536657-7

     * The BSD family tree.
       https://svnweb.freebsd.org/base/head/share/misc/bsd-family-tree?view=co
       or /usr/share/misc/bsd-family-tree on a FreeBSD machine.

     * Networked Computer Science Technical Reports Library.

     * Old BSD releases from the Computer Systems Research group (CSRG).
       http://www.mckusick.com/csrg/: The 4CD set covers all BSD versions
       from 1BSD to 4.4BSD and 4.4BSD-Lite2 (but not 2.11BSD, unfortunately).
       The last disk also holds the final sources plus the SCCS files.

     * Kernighan, Brian Unix: A History and a Memoir. Kindle Direct
       Publishing, 2020. ISBN 978-169597855-3

B.9. Periodicals, Journals, and Magazines

     * Admin Magazin (in German), published by Medialinx AG. ISSN: 2190-1066

     * BSD Magazine, published by Software Press Sp. z o.o. SK. ISSN:
       1898-9144

     * BSD Now - Video Podcast, published by Jupiter Broadcasting LLC

     * BSD Talk Podcast, by Will Backman

     * FreeBSD Journal, published by S&W Publishing, sponsored by The FreeBSD
       Foundation. ISBN: 978-0-615-88479-0

Appendix C. Resources on the Internet

   Table of Contents

   C.1. Websites

   C.2. Mailing Lists

   C.3. Usenet Newsgroups

   C.4. Official Mirrors

   The rapid pace of FreeBSD progress makes print media impractical as a
   means of following the latest developments. Electronic resources are the
   best, if not often the only, way to stay informed of the latest advances.
   Since FreeBSD is a volunteer effort, the user community itself also
   generally serves as a "technical support department" of sorts, with
   electronic mail, web forums, and USENET news being the most effective way
   of reaching that community.

   The most important points of contact with the FreeBSD user community are
   outlined below. Please send other resources not mentioned here to the
   FreeBSD documentation project mailing list so that they may also be
   included.

C.1. Websites

     * The FreeBSD Forums provide a web based discussion forum for FreeBSD
       questions and technical discussion.

     * The BSDConferences YouTube Channel provides a collection of high
       quality videos from BSD conferences around the world. This is a great
       way to watch key developers give presentations about new work in
       FreeBSD.

C.2. Mailing Lists

   The mailing lists are the most direct way of addressing questions or
   opening a technical discussion to a concentrated FreeBSD audience. There
   are a wide variety of lists on a number of different FreeBSD topics.
   Sending questions to the most appropriate mailing list will invariably
   assure a faster and more accurate response.

   The charters for the various lists are given at the bottom of this
   document. Please read the charter before joining or sending mail to any
   list. Most list subscribers receive many hundreds of FreeBSD related
   messages every day, and the charters and rules for use are meant to keep
   the signal-to-noise ratio of the lists high. To do less would see the
   mailing lists ultimately fail as an effective communications medium for
   the Project.

  Note:

   To test the ability to send email to FreeBSD lists, send a test message to
   freebsd-test. Please do not send test messages to any other list.

   When in doubt about what list to post a question to, see How to get best
   results from the FreeBSD-questions mailing list.

   Before posting to any list, please learn about how to best use the mailing
   lists, such as how to help avoid frequently-repeated discussions, by
   reading the Mailing List Frequently Asked Questions (FAQ) document.

   Archives are kept for all of the mailing lists and can be searched using
   the FreeBSD World Wide Web server. The keyword searchable archive offers
   an excellent way of finding answers to frequently asked questions and
   should be consulted before posting a question. Note that this also means
   that messages sent to FreeBSD mailing lists are archived in perpetuity.
   When protecting privacy is a concern, consider using a disposable
   secondary email address and posting only public information.

  C.2.1. List Summary

   General lists: The following are general lists which anyone is free (and
   encouraged) to join:

                List                                Purpose                   
   freebsd-advocacy               FreeBSD Evangelism                          
   freebsd-announce               Important events and Project milestones     
                                  (moderated)                                 
   freebsd-arch                   Architecture and design discussions         
                                  Discussions pertaining to the maintenance   
   freebsd-bugbusters             of the FreeBSD problem report database and  
                                  related tools                               
   freebsd-bugs                   Bug reports                                 
   freebsd-chat                   Non-technical items related to the FreeBSD  
                                  community                                   
   freebsd-chromium               FreeBSD-specific Chromium issues            
   freebsd-current                Discussion concerning the use of            
                                  FreeBSD-CURRENT                             
   freebsd-isp                    Issues for Internet Service Providers using 
                                  FreeBSD                                     
   freebsd-jobs                   FreeBSD employment and consulting           
                                  opportunities                               
   freebsd-quarterly-calls        Calls for quarterly status reports          
                                  (moderated)                                 
   freebsd-questions              User questions and technical support        
   freebsd-security-notifications Security notifications (moderated)          
   freebsd-stable                 Discussion concerning the use of            
                                  FreeBSD-STABLE                              
   freebsd-test                   Where to send test messages instead of to   
                                  one of the actual lists                     
   freebsd-women                  FreeBSD advocacy for women                  

   Technical lists: The following lists are for technical discussion. Read
   the charter for each list carefully before joining or sending mail to one
   as there are firm guidelines for their use and content.

            List                                Purpose                       
   freebsd-acpi           ACPI and power management development               
   freebsd-amd64          Porting FreeBSD to AMD64 systems (moderated)        
   freebsd-apache         Discussion about Apache related ports               
   freebsd-arm            Porting FreeBSD to ARM(R) processors                
   freebsd-atm            Using ATM networking with FreeBSD                   
   freebsd-bluetooth      Using Bluetooth(R) technology in FreeBSD            
   freebsd-cloud          FreeBSD on cloud platforms (EC2, GCE, Azure, etc.)  
   freebsd-cluster        Using FreeBSD in a clustered environment            
   freebsd-database       Discussing database use and development under       
                          FreeBSD                                             
   freebsd-desktop        Using and improving FreeBSD on the desktop          
   dev-ci                 Build and test reports from the Continuous          
                          Integration servers                                 
   dev-reviews            Notifications of the FreeBSD review system          
   freebsd-doc            Creating FreeBSD related documents                  
   freebsd-drivers        Writing device drivers for FreeBSD                  
   freebsd-dtrace         Using and working on DTrace in FreeBSD              
   freebsd-eclipse        FreeBSD users of Eclipse IDE, tools, rich client    
                          applications and ports.                             
   freebsd-elastic        FreeBSD-specific ElasticSearch discussions          
   freebsd-embedded       Using FreeBSD in embedded applications              
   freebsd-eol            Peer support of FreeBSD-related software that is no 
                          longer supported by the FreeBSD Project.            
   freebsd-emulation      Emulation of other systems such as                  
                          Linux/MS-DOS(R)/Windows(R)                          
   freebsd-enlightenment  Porting Enlightenment and Enlightenment             
                          applications                                        
   freebsd-erlang         FreeBSD-specific Erlang discussions                 
   freebsd-firewire       FreeBSD FireWire(R) (iLink, IEEE 1394) technical    
                          discussion                                          
   freebsd-fortran        Fortran on FreeBSD                                  
   freebsd-fs             File systems                                        
   freebsd-games          Support for Games on FreeBSD                        
   freebsd-gecko          Gecko Rendering Engine issues                       
   freebsd-geom           GEOM-specific discussions and implementations       
   freebsd-git            Discussion of git use in the FreeBSD project        
   freebsd-gnome          Porting GNOME and GNOME applications                
   freebsd-hackers        General technical discussion                        
   freebsd-haskell        FreeBSD-specific Haskell issues and discussions     
   freebsd-hardware       General discussion of hardware for running FreeBSD  
   freebsd-i18n           FreeBSD Internationalization                        
   freebsd-infiniband     Infiniband on FreeBSD                               
   freebsd-ipfw           Technical discussion concerning the redesign of the 
                          IP firewall code                                    
   freebsd-isdn           ISDN developers                                     
   freebsd-jail           Discussion about the jail(8) facility               
   freebsd-java           Java(TM) developers and people porting JDK(TM)s to  
                          FreeBSD                                             
   freebsd-kde            Porting KDE and KDE applications                    
   freebsd-lfs            Porting LFS to FreeBSD                              
   freebsd-mips           Porting FreeBSD to MIPS(R)                          
   freebsd-mono           Mono and C# applications on FreeBSD                 
   freebsd-multimedia     Multimedia applications                             
   freebsd-new-bus        Technical discussions about bus architecture        
   freebsd-net            Networking discussion and TCP/IP source code        
   freebsd-numerics       Discussions of high quality implementation of libm  
                          functions                                           
   freebsd-ocaml          FreeBSD-specific OCaml discussions                  
   freebsd-office         Office applications on FreeBSD                      
   freebsd-performance    Performance tuning questions for high               
                          performance/load installations                      
   freebsd-perl           Maintenance of a number of Perl-related ports       
   freebsd-pf             Discussion and questions about the packet filter    
                          firewall system                                     
   freebsd-pkg            Binary package management and package tools         
                          discussion                                          
   freebsd-pkg-fallout    Fallout logs from package building                  
   freebsd-pkgbase        Packaging the FreeBSD base system                   
   freebsd-platforms      Concerning ports to non Intel(R) architecture       
                          platforms                                           
   freebsd-ports          Discussion of the Ports Collection                  
   freebsd-ports-announce Important news and instructions about the Ports     
                          Collection (moderated)                              
   freebsd-ports-bugs     Discussion of the ports bugs/PRs                    
   freebsd-ppc            Porting FreeBSD to the PowerPC(R)                   
   freebsd-proliant       Technical discussion of FreeBSD on HP ProLiant      
                          server platforms                                    
   freebsd-python         FreeBSD-specific Python issues                      
   freebsd-rc             Discussion related to the rc.d system and its       
                          development                                         
   freebsd-realtime       Development of realtime extensions to FreeBSD       
   freebsd-riscv          Porting FreeBSD to RISC-V(R) systems                
   freebsd-ruby           FreeBSD-specific Ruby discussions                   
   freebsd-scsi           The SCSI subsystem                                  
   freebsd-security       Security issues affecting FreeBSD                   
   freebsd-snapshots      FreeBSD Development Snapshot Announcements          
   freebsd-sparc64        Porting FreeBSD to SPARC(R) based systems           
   freebsd-standards      FreeBSD's conformance to the C99 and the POSIX(R)   
                          standards                                           
   freebsd-sysinstall     sysinstall(8) development                           
   freebsd-tcltk          FreeBSD-specific Tcl/Tk discussions                 
   freebsd-testing        Testing on FreeBSD                                  
   freebsd-tex            Porting TeX and its applications to FreeBSD         
   freebsd-threads        Threading in FreeBSD                                
   freebsd-tilera         Porting FreeBSD to the Tilera family of CPUs        
   freebsd-tokenring      Support Token Ring in FreeBSD                       
   freebsd-toolchain      Maintenance of FreeBSD's integrated toolchain       
   freebsd-translators    Translating FreeBSD documents and programs          
   freebsd-transport      Discussions of transport level network protocols in 
                          FreeBSD                                             
   freebsd-usb            Discussing FreeBSD support for USB                  
   freebsd-virtualization Discussion of various virtualization techniques     
                          supported by FreeBSD                                
   freebsd-vuxml          Discussion on VuXML infrastructure                  
   freebsd-x11            Maintenance and support of X11 on FreeBSD           
   freebsd-xen            Discussion of the FreeBSD port to Xen(TM) -         
                          implementation and usage                            
   freebsd-xfce           XFCE for FreeBSD - porting and maintaining          
   freebsd-zope           Zope for FreeBSD - porting and maintaining          

   Limited lists: The following lists are for more specialized (and
   demanding) audiences and are probably not of interest to the general
   public. It is also a good idea to establish a presence in the technical
   lists before joining one of these limited lists in order to understand the
   communications etiquette involved.

          List                                Purpose                         
   freebsd-hubs        People running mirror sites (infrastructural support)  
   freebsd-user-groups User group coordination                                
   freebsd-wip-status  FreeBSD Work-In-Progress Status                        
   freebsd-wireless    Discussions of 802.11 stack, tools, device driver      
                       development                                            

   Digest lists: All of the above lists are available in a digest format.
   Once subscribed to a list, the digest options can be changed in the
   account options section.

   Commit message lists: The following lists are for people interested in
   seeing the log messages for changes to various areas of the source tree.

  Note:

   SVN log messages are sent to SVN lists.

              List            Source area    Area Description (source for)    
   dev-commits-doc-all        /usr/doc    All changes to the doc repository   
   dev-commits-ports-all      /usr/ports  All changes to the ports repository 
   dev-commits-ports-main     /usr/ports  All changes to the "main" branch of 
                                          the ports repository                
   dev-commits-ports-branches /usr/ports  All changes to the quarterly        
                                          branches of the ports repository    
   dev-commits-src-all        /usr/src    All changes to the src repository   
                                          All changes to the "main" branch of 
   dev-commits-src-main       /usr/src    the src repository (the             
                                          FreeBSD-CURRENT branch)             
   dev-commits-src-branches   /usr/src    All changes to all stable branches  
                                          of the src repository               

   SVN lists: The following lists are for people interested in seeing the SVN
   log messages for changes to various areas of the source tree.

  Note:

   Only SVN log messages are sent to SVN lists. After the SVN to Git
   Migration, the following lists no longer receives new commit messages.

           List            Source area       Area Description (source for)    
                                          All changes to the doc Subversion   
   svn-doc-all          /usr/doc          repository (except for user,        
                                          projects and translations)          
   svn-doc-head         /usr/doc          All changes to the "head" branch of 
                                          the doc Subversion repository       
   svn-doc-projects     /usr/doc/projects All changes to the projects area of 
                                          the doc Subversion repository       
                                          All changes to the administrative   
   svn-doc-svnadmin     /usr/doc          scripts, hooks, and other           
                                          configuration data of the doc       
                                          Subversion repository               
   svn-ports-all        /usr/ports        All changes to the ports Subversion 
                                          repository                          
   svn-ports-head       /usr/ports        All changes to the "head" branch of 
                                          the ports Subversion repository     
                                          All changes to the administrative   
   svn-ports-svnadmin   /usr/ports        scripts, hooks, and other           
                                          configuration data of the ports     
                                          Subversion repository               
                                          All changes to the src Subversion   
   svn-src-all          /usr/src          repository (except for user and     
                                          projects)                           
                                          All changes to the "head" branch of 
   svn-src-head         /usr/src          the src Subversion repository (the  
                                          FreeBSD-CURRENT branch)             
   svn-src-projects     /usr/projects     All changes to the projects area of 
                                          the src Subversion repository       
   svn-src-release      /usr/src          All changes to the releases area of 
                                          the src Subversion repository       
                                          All changes to the releng branches  
   svn-src-releng       /usr/src          of the src Subversion repository    
                                          (the security / release engineering 
                                          branches)                           
                                          All changes to the all stable       
   svn-src-stable       /usr/src          branches of the src Subversion      
                                          repository                          
   svn-src-stable-6     /usr/src          All changes to the stable/6 branch  
                                          of the src Subversion repository    
   svn-src-stable-7     /usr/src          All changes to the stable/7 branch  
                                          of the src Subversion repository    
   svn-src-stable-8     /usr/src          All changes to the stable/8 branch  
                                          of the src Subversion repository    
   svn-src-stable-9     /usr/src          All changes to the stable/9 branch  
                                          of the src Subversion repository    
   svn-src-stable-10    /usr/src          All changes to the stable/10 branch 
                                          of the src Subversion repository    
   svn-src-stable-11    /usr/src          All changes to the stable/11 branch 
                                          of the src Subversion repository    
   svn-src-stable-12    /usr/src          All changes to the stable/12 branch 
                                          of the src Subversion repository    
                                          All changes to the older stable     
   svn-src-stable-other /usr/src          branches of the src Subversion      
                                          repository                          
                                          All changes to the administrative   
   svn-src-svnadmin     /usr/src          scripts, hooks, and other           
                                          configuration data of the src       
                                          Subversion repository               
                                          All changes to the experimental     
   svn-src-user         /usr/src          user area of the src Subversion     
                                          repository                          
   svn-src-vendor       /usr/src          All changes to the vendor work area 
                                          of the src Subversion repository    

  C.2.2. How to Subscribe

   To subscribe to a list, click the list name at
   http://lists.FreeBSD.org/mailman/listinfo. The page that is displayed
   should contain all of the necessary subscription instructions for that
   list.

   To actually post to a given list, send mail to <listname@FreeBSD.org>. It
   will then be redistributed to mailing list members world-wide.

   To unsubscribe from a list, click on the URL found at the bottom of every
   email received from the list. It is also possible to send an email to
   <listname-unsubscribe@FreeBSD.org> to unsubscribe.

   It is important to keep discussion in the technical mailing lists on a
   technical track. To only receive important announcements, instead join the
   FreeBSD announcements mailing list, which is intended for infrequent
   traffic.

  C.2.3. List Charters

   All FreeBSD mailing lists have certain basic rules which must be adhered
   to by anyone using them. Failure to comply with these guidelines will
   result in two (2) written warnings from the FreeBSD Postmaster
   <postmaster@FreeBSD.org>, after which, on a third offense, the poster will
   removed from all FreeBSD mailing lists and filtered from further posting
   to them. We regret that such rules and measures are necessary at all, but
   today's Internet is a pretty harsh environment, it would seem, and many
   fail to appreciate just how fragile some of its mechanisms are.

   Rules of the road:

     * The topic of any posting should adhere to the basic charter of the
       list it is posted to. If the list is about technical issues, the
       posting should contain technical discussion. Ongoing irrelevant
       chatter or flaming only detracts from the value of the mailing list
       for everyone on it and will not be tolerated. For free-form discussion
       on no particular topic, the FreeBSD chat mailing list is freely
       available and should be used instead.

     * No posting should be made to more than 2 mailing lists, and only to 2
       when a clear and obvious need to post to both lists exists. For most
       lists, there is already a great deal of subscriber overlap and except
       for the most esoteric mixes (say "-stable & -scsi"), there really is
       no reason to post to more than one list at a time. If a message is
       received with multiple mailing lists on the Cc line, trim the Cc line
       before replying. The person who replies is still responsible for
       cross-posting, no matter who the originator might have been.

     * Personal attacks and profanity (in the context of an argument) are not
       allowed, and that includes users and developers alike. Gross breaches
       of netiquette, like excerpting or reposting private mail when
       permission to do so was not and would not be forthcoming, are frowned
       upon but not specifically enforced. However, there are also very few
       cases where such content would fit within the charter of a list and it
       would therefore probably rate a warning (or ban) on that basis alone.

     * Advertising of non-FreeBSD related products or services is strictly
       prohibited and will result in an immediate ban if it is clear that the
       offender is advertising by spam.

   Individual list charters:

   freebsd-acpi

           ACPI and power management development

   freebsd-announce

           Important events / milestones

           This is the mailing list for people interested only in occasional
           announcements of significant FreeBSD events. This includes
           announcements about snapshots and other releases. It contains
           announcements of new FreeBSD capabilities. It may contain calls
           for volunteers etc. This is a low volume, strictly moderated
           mailing list.

   freebsd-arch

           Architecture and design discussions

           This list is for discussion of the FreeBSD architecture. Messages
           will mostly be kept strictly technical in nature. Examples of
           suitable topics are:

              * How to re-vamp the build system to have several customized
                builds running at the same time.

              * What needs to be fixed with VFS to make Heidemann layers
                work.

              * How do we change the device driver interface to be able to
                use the same drivers cleanly on many buses and architectures.

              * How to write a network driver.

   freebsd-bluetooth

           Bluetooth(R) in FreeBSD

           This is the forum where FreeBSD's Bluetooth(R) users congregate.
           Design issues, implementation details, patches, bug reports,
           status reports, feature requests, and all matters related to
           Bluetooth(R) are fair game.

   freebsd-bugbusters

           Coordination of the Problem Report handling effort

           The purpose of this list is to serve as a coordination and
           discussion forum for the Bugmeister, his Bugbusters, and any other
           parties who have a genuine interest in the PR database. This list
           is not for discussions about specific bugs, patches or PRs.

   freebsd-bugs

           Bug reports

           This is the mailing list for reporting bugs in FreeBSD. Whenever
           possible, bugs should be submitted using the web interface to it.

   freebsd-chat

           Non technical items related to the FreeBSD community

           This list contains the overflow from the other lists about
           non-technical, social information. It includes discussion about
           whether Jordan looks like a toon ferret or not, whether or not to
           type in capitals, who is drinking too much coffee, where the best
           beer is brewed, who is brewing beer in their basement, and so on.
           Occasional announcements of important events (such as upcoming
           parties, weddings, births, new jobs, etc) can be made to the
           technical lists, but the follow ups should be directed to this
           -chat list.

   freebsd-chromium

           FreeBSD-specific Chromium issues

           This is a list for the discussion of Chromium support for FreeBSD.
           This is a technical list to discuss development and installation
           of Chromium.

   freebsd-cloud

           Running FreeBSD on various cloud platforms

           This list discusses running FreeBSD on Amazon EC2, Google Compute
           Engine, Microsoft Azure, and other cloud computing platforms.

   freebsd-core

           FreeBSD core team

           This is an internal mailing list for use by the core members.
           Messages can be sent to it when a serious FreeBSD-related matter
           requires arbitration or high-level scrutiny.

   freebsd-current

           Discussions about the use of FreeBSD-CURRENT

           This is the mailing list for users of FreeBSD-CURRENT. It includes
           warnings about new features coming out in -CURRENT that will
           affect the users, and instructions on steps that must be taken to
           remain -CURRENT. Anyone running "CURRENT" must subscribe to this
           list. This is a technical mailing list for which strictly
           technical content is expected.

   freebsd-desktop

           Using and improving FreeBSD on the desktop

           This is a forum for discussion of FreeBSD on the desktop. It is
           primarily a place for desktop porters and users to discuss issues
           and improve FreeBSD's desktop support.

   dev-ci

           Continuous Integration reports of build and test results

           All Continuous Integration reports of build and test results

   dev-reviews

           Notifications of work in progress in FreeBSD's review tool

           Automated notifications of work in progress for review in
           FreeBSD's review tools, including patches.

   freebsd-doc

           Documentation Project

           This mailing list is for the discussion of issues and projects
           related to the creation of documentation for FreeBSD. The members
           of this mailing list are collectively referred to as "The FreeBSD
           Documentation Project". It is an open list; feel free to join and
           contribute!

   freebsd-drivers

           Writing device drivers for FreeBSD

           This is a forum for technical discussions related to device
           drivers on FreeBSD. It is primarily a place for device driver
           writers to ask questions about how to write device drivers using
           the APIs in the FreeBSD kernel.

   freebsd-dtrace

           Using and working on DTrace in FreeBSD

           DTrace is an integrated component of FreeBSD that provides a
           framework for understanding the kernel as well as user space
           programs at run time. The mailing list is an archived discussion
           for developers of the code as well as those using it.

   freebsd-eclipse

           FreeBSD users of Eclipse IDE, tools, rich client applications and
           ports.

           The intention of this list is to provide mutual support for
           everything to do with choosing, installing, using, developing and
           maintaining the Eclipse IDE, tools, rich client applications on
           the FreeBSD platform and assisting with the porting of Eclipse IDE
           and plugins to the FreeBSD environment.

           The intention is also to facilitate exchange of information
           between the Eclipse community and the FreeBSD community to the
           mutual benefit of both.

           Although this list is focused primarily on the needs of Eclipse
           users it will also provide a forum for those who would like to
           develop FreeBSD specific applications using the Eclipse framework.

   freebsd-embedded

           Using FreeBSD in embedded applications

           This list discusses topics related to using FreeBSD in embedded
           systems. This is a technical mailing list for which strictly
           technical content is expected. For the purpose of this list,
           embedded systems are those computing devices which are not
           desktops and which usually serve a single purpose as opposed to
           being general computing environments. Examples include, but are
           not limited to, all kinds of phone handsets, network equipment
           such as routers, switches and PBXs, remote measuring equipment,
           PDAs, Point Of Sale systems, and so on.

   freebsd-emulation

           Emulation of other systems such as Linux/MS-DOS(R)/Windows(R)

           This is a forum for technical discussions related to running
           programs written for other operating systems on FreeBSD.

   freebsd-enlightenment

           Enlightenment

           Discussions concerning the Enlightenment Desktop Environment for
           FreeBSD systems. This is a technical mailing list for which
           strictly technical content is expected.

   freebsd-eol

           Peer support of FreeBSD-related software that is no longer
           supported by the FreeBSD Project.

           This list is for those interested in providing or making use of
           peer support of FreeBSD-related software for which the FreeBSD
           Project no longer provides official support in the form of
           security advisories and patches.

   freebsd-firewire

           FireWire(R) (iLink, IEEE 1394)

           This is a mailing list for discussion of the design and
           implementation of a FireWire(R) (aka IEEE 1394 aka iLink)
           subsystem for FreeBSD. Relevant topics specifically include the
           standards, bus devices and their protocols, adapter
           boards/cards/chips sets, and the architecture and implementation
           of code for their proper support.

   freebsd-fortran

           Fortran on FreeBSD

           This is the mailing list for discussion of Fortran related ports
           on FreeBSD: compilers, libraries, scientific and engineering
           applications from laptops to HPC clusters.

   freebsd-fs

           File systems

           Discussions concerning FreeBSD filesystems. This is a technical
           mailing list for which strictly technical content is expected.

   freebsd-games

           Games on FreeBSD

           This is a technical list for discussions related to bringing games
           to FreeBSD. It is for individuals actively working on porting
           games to FreeBSD, to bring up problems or discuss alternative
           solutions. Individuals interested in following the technical
           discussion are also welcome.

   freebsd-gecko

           Gecko Rendering Engine

           This is a forum about Gecko applications using FreeBSD.

           Discussion centers around Gecko Ports applications, their
           installation, their development and their support within FreeBSD.

   freebsd-geom

           GEOM

           Discussions specific to GEOM and related implementations. This is
           a technical mailing list for which strictly technical content is
           expected.

   freebsd-git

           Use of git in the FreeBSD project

           Discussions of how to use git in FreeBSD infrastructure including
           the github mirror and other uses of git for project collaboration.
           Discussion area for people using git against the FreeBSD github
           mirror. People wanting to get started with the mirror or git in
           general on FreeBSD can ask here.

   freebsd-gnome

           GNOME

           Discussions concerning The GNOME Desktop Environment for FreeBSD
           systems. This is a technical mailing list for which strictly
           technical content is expected.

   freebsd-infiniband

           Infiniband on FreeBSD

           Technical mailing list discussing Infiniband, OFED, and OpenSM on
           FreeBSD.

   freebsd-ipfw

           IP Firewall

           This is the forum for technical discussions concerning the
           redesign of the IP firewall code in FreeBSD. This is a technical
           mailing list for which strictly technical content is expected.

   freebsd-isdn

           ISDN Communications

           This is the mailing list for people discussing the development of
           ISDN support for FreeBSD.

   freebsd-java

           Java(TM) Development

           This is the mailing list for people discussing the development of
           significant Java(TM) applications for FreeBSD and the porting and
           maintenance of JDK(TM)s.

   freebsd-jobs

           Jobs offered and sought

           This is a forum for posting employment notices specifically
           related to FreeBSD and resumes from those seeking FreeBSD-related
           employment. This is not a mailing list for general employment
           issues since adequate forums for that already exist elsewhere.

           Note that this list, like other FreeBSD.org mailing lists, is
           distributed worldwide. Be clear about the geographic location and
           the extent to which telecommuting or assistance with relocation is
           available.

           Email should use open formats only - preferably plain text, but
           basic Portable Document Format (PDF), HTML, and a few others are
           acceptable to many readers. Closed formats such as Microsoft(R)
           Word (.doc) will be rejected by the mailing list server.

   freebsd-kde

           KDE

           Discussions concerning KDE on FreeBSD systems. This is a technical
           mailing list for which strictly technical content is expected.

   freebsd-hackers

           Technical discussions

           This is a forum for technical discussions related to FreeBSD. This
           is the primary technical mailing list. It is for individuals
           actively working on FreeBSD, to bring up problems or discuss
           alternative solutions. Individuals interested in following the
           technical discussion are also welcome. This is a technical mailing
           list for which strictly technical content is expected.

   freebsd-hardware

           General discussion of FreeBSD hardware

           General discussion about the types of hardware that FreeBSD runs
           on, various problems and suggestions concerning what to buy or
           avoid.

   freebsd-hubs

           Mirror sites

           Announcements and discussion for people who run FreeBSD mirror
           sites.

   freebsd-isp

           Issues for Internet Service Providers

           This mailing list is for discussing topics relevant to Internet
           Service Providers (ISPs) using FreeBSD. This is a technical
           mailing list for which strictly technical content is expected.

   freebsd-mono

           Mono and C# applications on FreeBSD

           This is a list for discussions related to the Mono development
           framework on FreeBSD. This is a technical mailing list. It is for
           individuals actively working on porting Mono or C# applications to
           FreeBSD, to bring up problems or discuss alternative solutions.
           Individuals interested in following the technical discussion are
           also welcome.

   freebsd-ocaml

           FreeBSD-specific OCaml discussions

           This is a list for discussions related to the OCaml support on
           FreeBSD. This is a technical mailing list. It is for individuals
           working on OCaml ports, 3rd party libraries and frameworks.
           Individuals interested in the technical discussion are also
           welcome.

   freebsd-office

           Office applications on FreeBSD

           Discussion centers around office applications, their installation,
           their development and their support within FreeBSD.

   freebsd-ops-announce

           Project Infrastructure Announcements

           This is the mailing list for people interested in changes and
           issues related to the FreeBSD.org Project infrastructure.

           This moderated list is strictly for announcements: no replies,
           requests, discussions, or opinions.

   freebsd-performance

           Discussions about tuning or speeding up FreeBSD

           This mailing list exists to provide a place for hackers,
           administrators, and/or concerned parties to discuss performance
           related topics pertaining to FreeBSD. Acceptable topics includes
           talking about FreeBSD installations that are either under high
           load, are experiencing performance problems, or are pushing the
           limits of FreeBSD. Concerned parties that are willing to work
           toward improving the performance of FreeBSD are highly encouraged
           to subscribe to this list. This is a highly technical list ideally
           suited for experienced FreeBSD users, hackers, or administrators
           interested in keeping FreeBSD fast, robust, and scalable. This
           list is not a question-and-answer list that replaces reading
           through documentation, but it is a place to make contributions or
           inquire about unanswered performance related topics.

   freebsd-pf

           Discussion and questions about the packet filter firewall system

           Discussion concerning the packet filter (pf) firewall system in
           terms of FreeBSD. Technical discussion and user questions are both
           welcome. This list is also a place to discuss the ALTQ QoS
           framework.

   freebsd-pkg

           Binary package management and package tools discussion

           Discussion of all aspects of managing FreeBSD systems by using
           binary packages to install software, including binary package
           toolkits and formats, their development and support within
           FreeBSD, package repository management, and third party packages.

           Note that discussion of ports which fail to generate packages
           correctly should generally be considered as ports problems, and so
           inappropriate for this list.

   freebsd-pkg-fallout

           Fallout logs from package building

           All packages building failures logs from the package building
           clusters

   freebsd-pkgbase

           Packaging the FreeBSD base system.

           Discussions surrounding implementation and issues regarding
           packaging the FreeBSD base system.

   freebsd-platforms

           Porting to Non Intel(R) platforms

           Cross-platform FreeBSD issues, general discussion and proposals
           for non Intel(R) FreeBSD ports. This is a technical mailing list
           for which strictly technical content is expected.

   freebsd-ports

           Discussion of "ports"

           Discussions concerning FreeBSD's "ports collection" (/usr/ports),
           ports infrastructure, and general ports coordination efforts. This
           is a technical mailing list for which strictly technical content
           is expected.

   freebsd-ports-announce

           Important news and instructions about the FreeBSD "Ports
           Collection"

           Important news for developers, porters, and users of the "Ports
           Collection" (/usr/ports), including architecture/infrastructure
           changes, new capabilities, critical upgrade instructions, and
           release engineering information. This is a low-volume mailing
           list, intended for announcements.

   freebsd-ports-bugs

           Discussion of "ports" bugs

           Discussions concerning problem reports for FreeBSD's "ports
           collection" (/usr/ports), proposed ports, or modifications to
           ports. This is a technical mailing list for which strictly
           technical content is expected.

   freebsd-proliant

           Technical discussion of FreeBSD on HP ProLiant server platforms

           This mailing list is to be used for the technical discussion of
           the usage of FreeBSD on HP ProLiant servers, including the
           discussion of ProLiant-specific drivers, management software,
           configuration tools, and BIOS updates. As such, this is the
           primary place to discuss the hpasmd, hpasmcli, and hpacucli
           modules.

   freebsd-python

           Python on FreeBSD

           This is a list for discussions related to improving Python-support
           on FreeBSD. This is a technical mailing list. It is for
           individuals working on porting Python, its third party modules and
           Zope stuff to FreeBSD. Individuals interested in following the
           technical discussion are also welcome.

   freebsd-questions

           User questions

           This is the mailing list for questions about FreeBSD. Do not send
           "how to" questions to the technical lists unless the question is
           quite technical.

   freebsd-ruby

           FreeBSD-specific Ruby discussions

           This is a list for discussions related to the Ruby support on
           FreeBSD. This is a technical mailing list. It is for individuals
           working on Ruby ports, third party libraries and frameworks.

           Individuals interested in the technical discussion are also
           welcome.

   freebsd-scsi

           SCSI subsystem

           This is the mailing list for people working on the SCSI subsystem
           for FreeBSD. This is a technical mailing list for which strictly
           technical content is expected.

   freebsd-security

           Security issues

           FreeBSD computer security issues (DES, Kerberos, known security
           holes and fixes, etc). This is a technical mailing list for which
           strictly technical discussion is expected. Note that this is not a
           question-and-answer list, but that contributions (BOTH question
           AND answer) to the FAQ are welcome.

   freebsd-security-notifications

           Security Notifications

           Notifications of FreeBSD security problems and fixes. This is not
           a discussion list. The discussion list is FreeBSD-security.

   freebsd-snapshots

           FreeBSD Development Snapshot Announcements

           This list provides notifications about the availability of new
           FreeBSD development snapshots for the head/ and stable/ branches.

   freebsd-stable

           Discussions about the use of FreeBSD-STABLE

           This is the mailing list for users of FreeBSD-STABLE. "STABLE" is
           the branch where development continues after a RELEASE, including
           bug fixes and new features. The ABI is kept stable for binary
           compatibility. It includes warnings about new features coming out
           in -STABLE that will affect the users, and instructions on steps
           that must be taken to remain -STABLE. Anyone running "STABLE"
           should subscribe to this list. This is a technical mailing list
           for which strictly technical content is expected.

   freebsd-standards

           C99 & POSIX Conformance

           This is a forum for technical discussions related to FreeBSD
           Conformance to the C99 and the POSIX standards.

   freebsd-teaching

           Teaching with FreeBSD

           Non technical mailing list discussing teaching with FreeBSD.

   freebsd-testing

           Testing on FreeBSD

           Technical mailing list discussing testing on FreeBSD, including
           ATF/Kyua, test build infrastructure, port tests to FreeBSD from
           other operating systems (NetBSD, ...), etc.

   freebsd-tex

           Porting TeX and its applications to FreeBSD

           This is a technical mailing list for discussions related to TeX
           and its applications on FreeBSD. It is for individuals actively
           working on porting TeX to FreeBSD, to bring up problems or discuss
           alternative solutions. Individuals interested in following the
           technical discussion are also welcome.

   freebsd-toolchain

           Maintenance of FreeBSD's integrated toolchain

           This is the mailing list for discussions related to the
           maintenance of the toolchain shipped with FreeBSD. This could
           include the state of Clang and GCC, but also pieces of software
           such as assemblers, linkers and debuggers.

   freebsd-transport

           Discussions of transport level network protocols in FreeBSD

           The transport mailing list exists for the discussion of issues and
           designs around the transport level protocols in the FreeBSD
           network stack, including TCP, SCTP and UDP. Other networking
           topics, including driver specific and network protocol issues
           should be discussed on the FreeBSD networking mailing list.

   freebsd-translators

           Translating FreeBSD documents and programs

           A discussion list where translators of FreeBSD documents from
           English into other languages can talk about translation methods
           and tools. New members are asked to introduce themselves and
           mention the languages they are interested in translating.

   freebsd-usb

           Discussing FreeBSD support for USB

           This is a mailing list for technical discussions related to
           FreeBSD support for USB.

   freebsd-user-groups

           User Group Coordination List

           This is the mailing list for the coordinators from each of the
           local area Users Groups to discuss matters with each other and a
           designated individual from the Core Team. This mail list should be
           limited to meeting synopsis and coordination of projects that span
           User Groups.

   freebsd-virtualization

           Discussion of various virtualization techniques supported by
           FreeBSD

           A list to discuss the various virtualization techniques supported
           by FreeBSD. On one hand the focus will be on the implementation of
           the basic functionality as well as adding new features. On the
           other hand users will have a forum to ask for help in case of
           problems or to discuss their use cases.

   freebsd-wip-status

           FreeBSD Work-In-Progress Status

           This mailing list can be used by developers to announce the
           creation and progress of FreeBSD related work. Messages will be
           moderated. It is suggested to send the message "To:" a more
           topical FreeBSD list and only "BCC:" this list. This way the WIP
           can also be discussed on the topical list, as no discussion is
           allowed on this list.

           Look inside the archives for examples of suitable messages.

           An editorial digest of the messages to this list might be posted
           to the FreeBSD website every few months as part of the Status
           Reports [3]. Past reports are archived.

   freebsd-wireless

           Discussions of 802.11 stack, tools device driver development

           The FreeBSD-wireless list focuses on 802.11 stack (sys/net80211),
           device driver and tools development. This includes bugs, new
           features and maintenance.

   freebsd-xen

           Discussion of the FreeBSD port to Xen(TM) - implementation and
           usage

           A list that focuses on the FreeBSD Xen(TM) port. The anticipated
           traffic level is small enough that it is intended as a forum for
           both technical discussions of the implementation and design
           details as well as administrative deployment issues.

   freebsd-xfce

           XFCE

           This is a forum for discussions related to bring the XFCE
           environment to FreeBSD. This is a technical mailing list. It is
           for individuals actively working on porting XFCE to FreeBSD, to
           bring up problems or discuss alternative solutions. Individuals
           interested in following the technical discussion are also welcome.

   freebsd-zope

           Zope

           This is a forum for discussions related to bring the Zope
           environment to FreeBSD. This is a technical mailing list. It is
           for individuals actively working on porting Zope to FreeBSD, to
           bring up problems or discuss alternative solutions. Individuals
           interested in following the technical discussion are also welcome.

  C.2.4. Filtering on the Mailing Lists

   The FreeBSD mailing lists are filtered in multiple ways to avoid the
   distribution of spam, viruses, and other unwanted emails. The filtering
   actions described in this section do not include all those used to protect
   the mailing lists.

   Only certain types of attachments are allowed on the mailing lists. All
   attachments with a MIME content type not found in the list below will be
   stripped before an email is distributed on the mailing lists.

     * application/octet-stream

     * application/pdf

     * application/pgp-signature

     * application/x-pkcs7-signature

     * message/rfc822

     * multipart/alternative

     * multipart/related

     * multipart/signed

     * text/html

     * text/plain

     * text/x-diff

     * text/x-patch

  Note:

   Some of the mailing lists might allow attachments of other MIME content
   types, but the above list should be applicable for most of the mailing
   lists.

   If an email contains both an HTML and a plain text version, the HTML
   version will be removed. If an email contains only an HTML version, it
   will be converted to plain text.

C.3. Usenet Newsgroups

   In addition to two FreeBSD specific newsgroups, there are many others in
   which FreeBSD is discussed or are otherwise relevant to FreeBSD users.

  C.3.1. BSD Specific Newsgroups

     * comp.unix.bsd.freebsd.announce

     * comp.unix.bsd.freebsd.misc

     * de.comp.os.unix.bsd (German)

     * fr.comp.os.bsd (French)

  C.3.2. Other UNIX(R) Newsgroups of Interest

     * comp.unix

     * comp.unix.questions

     * comp.unix.admin

     * comp.unix.programmer

     * comp.unix.shell

     * comp.unix.misc

     * comp.unix.bsd

  C.3.3. X Window System

     * comp.windows.x

C.4. Official Mirrors

   Central Servers, Armenia, Australia, Austria, Czech Republic, Denmark,
   Finland, France, Germany, Hong Kong, Ireland, Japan, Latvia, Lithuania,
   Netherlands, Norway, Russia, Slovenia, South Africa, Spain, Sweden,
   Switzerland, Taiwan, United Kingdom, USA.

   (as of UTC)

     * Central Servers

          * https://www.FreeBSD.org/

     * Armenia

          * http://www1.am.FreeBSD.org/ (IPv6)

     * Australia

          * http://www.au.FreeBSD.org/

          * http://www2.au.FreeBSD.org/

     * Austria

          * http://www.at.FreeBSD.org/ (IPv6)

     * Czech Republic

          * http://www.cz.FreeBSD.org/ (IPv6)

     * Denmark

          * http://www.dk.FreeBSD.org/ (IPv6)

     * Finland

          * http://www.fi.FreeBSD.org/

     * France

          * http://www1.fr.FreeBSD.org/

     * Germany

          * http://www.de.FreeBSD.org/

     * Hong Kong

          * http://www.hk.FreeBSD.org/

     * Ireland

          * http://www.ie.FreeBSD.org/

     * Japan

          * http://www.jp.FreeBSD.org/www.FreeBSD.org/ (IPv6)

     * Latvia

          * http://www.lv.FreeBSD.org/

     * Lithuania

          * http://www.lt.FreeBSD.org/

     * Netherlands

          * http://www.nl.FreeBSD.org/

     * Norway

          * http://www.no.FreeBSD.org/

     * Russia

          * http://www.ru.FreeBSD.org/ (IPv6)

     * Slovenia

          * http://www.si.FreeBSD.org/

     * South Africa

          * http://www.za.FreeBSD.org/

     * Spain

          * http://www.es.FreeBSD.org/

          * http://www2.es.FreeBSD.org/

     * Sweden

          * http://www.se.FreeBSD.org/

     * Switzerland

          * http://www.ch.FreeBSD.org/ (IPv6)

          * http://www2.ch.FreeBSD.org/ (IPv6)

     * Taiwan

          * http://www.tw.FreeBSD.org/

          * http://www2.tw.FreeBSD.org/

          * http://www4.tw.FreeBSD.org/

          * http://www5.tw.FreeBSD.org/ (IPv6)

     * United Kingdom

          * http://www1.uk.FreeBSD.org/

          * http://www3.uk.FreeBSD.org/

     * USA

          * http://www5.us.FreeBSD.org/ (IPv6)

     ----------------------------------------------------------------------

   [3] https://www.freebsd.org/news/status/

Appendix D. OpenPGP Keys

   Table of Contents

   D.1. Officers

   The OpenPGP keys of the FreeBSD.org officers are shown here. These keys
   can be used to verify a signature or send encrypted email to one of the
   officers. A full list of FreeBSD OpenPGP keys is available in the PGP Keys
   article. The complete keyring can be downloaded at
   https://www.FreeBSD.org/doc/pgpkeyring.txt.

D.1. Officers

  D.1.1. Security Officer Team <security-officer@FreeBSD.org>

 pub   rsa4096/D39792F49EA7E5C2 2017-08-16 [SC] [expires: 2023-01-02]
       Key fingerprint = FC0E 878A E5AF E788 028D  6355 D397 92F4 9EA7 E5C2
 uid                            FreeBSD Security Officer <security-officer@FreeBSD.org>
 sub   rsa4096/6DD0A349F26ADEFD 2017-08-16 [E] [expires: 2023-01-02]


 -----BEGIN PGP PUBLIC KEY BLOCK-----

 mQINBFmT2+ABEACrTVJ7Z/MuDeyKFqoTFnm5FrGG55k66RLeKivzQzq/tT/6RKO9
 K8DaEvSIqD9b0/xgK02KgLSdp0Bucq8HLDFYUk3McFa6Z3YwjobNCWkxc72ipvVl
 uAOGN4H6fuoYOpeg4cLK1H9pktUIrzONTCixaZzc/Bu6X+aX4ywGeCfsuu8g5v03
 fLCPBLLgf3Bm5wsyZ6ZaGmsmILrWzd+d/rbr35Mcc5BekdgywUI4R191qo1bdrw9
 mEJP1V7Ik3jpExOsNnuhMTvm5OQMeCTfUvVEOtBU15QtbT+1LXF5FIOgML0LwS5v
 RHZN+5w/xvzSnEULpj24UuMKLDs/u9rj8U/zET8QaE+oG7m/mr4jJWZEmdX8HKdO
 WrpnVj6UAppk72qdBIEfLsOW2xB/NOjJpppbCQH3+sw7DRYA2UnKE9Mptj/KKiE4
 cs4c8Cupo2WSu93lEZDC5rCrULpT2lFeEXnRYlC/5oIgY5w9sFide9VI4CzHkkWX
 Z2NPW/i1w3mFhoXjvnNLGOYMfAMKPxsRC2/Bn3bY0IhKvuIZ4rAeu7FTmKDDqFKQ
 YEcrUOW74ZVng17AB29xzjWr4zNJVvp/CybFiUb8JoKkwtVWRqAVZIEgenAjU40d
 G5+W4e+ccL0mfTQfEBbXRjnL2BL2tnaoBR42cTfbZGRucPHz7MrlKBEeZQARAQAB
 tDdGcmVlQlNEIFNlY3VyaXR5IE9mZmljZXIgPHNlY3VyaXR5LW9mZmljZXJARnJl
 ZUJTRC5vcmc+iQJUBBMBCgA+FiEE/A6HiuWv54gCjWNV05eS9J6n5cIFAlmT2+AC
 GwMFCQoek4AFCwkIBwMFFQoJCAsFFgIDAQACHgECF4AACgkQ05eS9J6n5cKd9A/9
 Fz3uGjNy28D0ALT1d/JJGzdQ2R3YwspHk9KHBr1LePkog9wf1WRalwCeNtPmA+g5
 cn24psuzOeh1tRElImTZ2eE2ENPZ9XzK/J0ok0nK42MvmIwmMCyz+CaWv9GXW+FK
 0oXnFmHi4YaQUVN3p+45TGkD9T+O5biVww7P47n/NnWsTfhLx0bzC7LyjPKXINai
 /LgPgtlcOgY65/YhW/qhADCkoU7qMp9is41jMjTu1WB3OBPJkUkNpHfu6r15y8FN
 Wqsk7K4W6Obr/WQ6VKGGXgh/a5mTcaEoFGMO16uHijAY4nXeb2HGZlBKxgmPH9Ur
 aT4A9Pz/n+rIRMrK+rs+msFPemQHHNBYxy+x99uBpRBNyT2Su6GouZIxu5J16aIM
 V0ZyOy/dy7m/uJ4sMhJPqKkd8a+MoQs/2L1M1y1EAzsO/QZqIrKrCluaftNN9k/B
 qU0XClSDqB6sRMF7HFzYqb+f+M6cwSL/3Cp1Yx4rZ/onEE/MdWp64+3R87dETTXd
 5tWXQw04qOhfPri5cBTI7r3t/qMO1iNXCGSG5RJbGkas6N6t6Mj83L4ItjI8doLf
 aSIWZjj1XP3/me2hFJ6h2G5y5A+khO4ZwhC0ATFSq1fYbVGHw5AtfthIgNn8FoWu
 +Sb8h7/RqTr7F6LgWagAoAh0GtVj02SVABZjcNZz/AKJAjcEEAEKACEWIQQc9/9v
 rfXKn74bjLLtZ+zWXc9q5wUCWZPcTAMFAngACgkQ7Wfs1l3PauflkRAAgYcaBX0Y
 ic4btxKoP/eOVpgUciOPPKEhDCiloQDyf4XQnZFDoMfjgcHpbLTBZ6kiAz2UzDGr
 fJ4yUqrD+xfixUfCd5YpwzsaSpCGzDzSxOBcP/SpuAFhe40awSOIf5MruQar9Mlf
 33JyslDLULXXeewAq2pcGk0/WrrOragI6Cs2vPGy9XP96VvLxyhjrWjlKmnO+//w
 UF8oIO5hhKoqbtoxxlcqJgsWVyHch0mnPzvr6GWwoPhFXocnh1oPdbLjX1AwmGm9
 ltEYMge4QxONIXlXJR0TvuDuJOaLNvTOC3OI8L97fdBcZS7eNJrG5FAYR5Ft3ISf
 KJowIsSLGDt/cYApqpyP2pv7FpCvnwHgXHYar7/q4zhngCFRxQ2DPUx1cIJQ3Bgh
 HZolKyK1X7XE5ZVDfZ3s3gcHSVKS89pipgHHZNr4sSmOanA8rXHcyHS4o2zSi1ie
 r4iBwnOk6cCd6UNzEIiq0y/XhP/sc7xeL0mn3wDuV7jDBP9sp65sexL1qtIAfnzL
 pLQevm0z41ifrUH5nNeL6RdbXpaoXc8M4PJJeQKJDu04KzLcQpZdUdCJsbS6QO9w
 srWR8enQXPEhz2CO4L77bM9TgYO29222jTqEPcbXcmxF/klxO1rpssTTHUnHHi1Z
 LUGYCbZPjt+laTJ2YPHTjUtN1Jw85vSKCEuJATMEEAEKAB0WIQS7KNQLNg7uk2rt
 FW/l97zLo73d+AUCWjSYRwAKCRDl97zLo73d+JKyB/9N5Ytao12nD5QzMLvceGh5
 otCLN99TUryYiDVDLoNkBivq3jHQA/hOX2rwEueFq0+LF8/2DnglJuUICNtCxIzL
 WXXf/Hr5iWBUQ0JxYNPQzzjdMSXGE0WMwYVpAbCGxHpIsetKLdHUCwneYhaywe3I
 KzmRJSDJGV1IJB0sAfoFtgybZXHgIR61jQjtnNmmyYXliYCd0wmIhXQDFN91tzzG
 +EZdJ3Fao9JsMC+x55jO6EOLVySZgRF5E8vCeKUWemQciKFC7EhKcljILPYAA21u
 NmHCAgRHKWU9JMdFK0w9lQuN2HQaNfkahjarTNM/Q6LwxY0dLG0vVYifE085WFAf
 uQINBFmT2+ABEACxi39m5nQZexzY3c9sg/w5mUYCD89ZNSkj427gduQMYYGn7YW6
 jSPfVJ/V3+PDK824c0a0XasyDapQFY1CPTZYrReRPoyjb8tJjsSVGXXCTFpJZlFU
 br6kS9mgcx58Sypke2PMVk73+W1N1Yco+nahfTECRuM2/T2zHHr0AdKuBPF28U+H
 TxyLatKoIgQwHDs4E/f4ZTbAoHvu3PixAl7XHVXCgz0cHaLhRljXizbZDXngOdGm
 lqdFlAIpL6/l8E3m1Er0m3IfFo6qSzWRHg/KaBGIL4YKetJ6ACjlkCe5qbatDpmk
 gWlg3Ux4RBVjyCK834Xh7eZpEcNf2iwpm28glWh7XMHGUplTHkU3PWQ4vGfNxXB8
 HBOd9r02/cHL6MiHwhCAfIzZGVtqR0i9Ira57TMdXTpJWNXUcgsCMsi/Bg2a+hsn
 aiYLrZc18uNL5nqOqsqKG3c1TcmeN7nbxVgnrNST4AjteulkhmB9p8tNOXA3u979
 OO0T5LPwdqIpobdZ0lfw4URnAGw4Wd4Sm9PtRw0RvuAk2M2e5KXNyxPWAuMVkoRR
 a7wG6h/R8pki54Gexyc+JkfB4ZcOrzHNLurw6DhxroyfRs8WEgX0wNIGmJvCXSBG
 54jb5w9qudYwzIg4YPfvuX8sfeY8MTNhal3rF0tvVloGj3l709wlaWlBYwARAQAB
 iQI8BBgBCgAmFiEE/A6HiuWv54gCjWNV05eS9J6n5cIFAlmT2+ACGwwFCQoek4AA
 CgkQ05eS9J6n5cKhWw/+PT0R4r2gPAxI8ESEe380BYOmneNAH24MFOgWXqWCj4zX
 Uz992BVnW2aL5nH4O5d822LGeCrYUC7SCpQvlifdHZHjobgtizLTwuu40bc3gSOz
 cxWlx2jKfx3Ezn6QQz2mhhK6fZ1AO0ObiQxQq25ldURep95L78E/C8XkCe11YlUR
 ng3wQKeHM7awZWRw/QBC92haHuVtU3cx7At+zQL7jTBKSZqd34zzs0uoXIhk2h94
 O07MMDZ8z8MeU337vdL+RKYtD2bljLwpf7/kqg1D/q44RJ4ZpZcha9G0GvtLaQg2
 +MAPlLg1vOWZ8wOTLaQHm+uzYRpkqxkIV8OuVd4UikCd8t3VNjNG5rG/YRNIAX0A
 UEzs6oMF5YOFE8LmykesbUHAbC07Vcb0AsT5u3XKixDiIpPdnYSwGlkvoOVVLdeh
 q/aXLK9V8BpViG5+a8xP2fdF1eMqdnrKAsiO4GEiq193PN/FA049VeIs3fd0izAa
 x7+ag1MGtoF5Pij5iTVJm6phH5SUd1P3FY3OmclxWj/MbL4ba/G/6FWcy5NXxdw9
 L1bRqaM2KEHJ67aF6NZz7UMldwExAWzFbUon1LUpKysAukxVf0EnntydBeVOQ+JO
 HdqEpirrVLMpxPttUB2xxbo947nMj7/Bnme2gvb0vxaC9xSGVxrpW9cg5iCwSdc=
 =8rds
 -----END PGP PUBLIC KEY BLOCK-----

  D.1.2. Security Team Secretary <secteam-secretary@FreeBSD.org>

 pub   4096R/3CB2EAFCC3D6C666 2013-09-24 [expires: 2018-01-01]
       Key fingerprint = FA97 AA04 4DF9 0969 D5EF  4ADA 3CB2 EAFC C3D6 C666
 uid                          FreeBSD Security Team Secretary <secteam-secretary@FreeBSD.org>
 sub   4096R/509B26612335EB65 2013-09-24 [expires: 2018-01-01]

 -----BEGIN PGP PUBLIC KEY BLOCK-----

 mQINBFJBjIIBEADadvvpXSkdnBOGV2xcsFwBBcSwAdryWuLk6v2VxjwsPcY6Lwqz
 NAZr2Ox1BaSgX7106Psa6v9si8nxoOtMc5BCM/ps/fmedFU48YtqOTGF+utxvACg
 Ou6SKintEMUa1eoPcww1jzDZ3mxx49bQaNAJLjVxeiAZoYHe9loTe1fxsprCONnx
 Era1hrI+YA2KjMWDORcwa0sSXRCI3V+b4PUnbMUOQa3fFVUriM4QjjUBU6hW0Ub0
 GDPcZq45nd7PoPPtb3/EauaYfk/zdx8Xt0OmuKTi9/vMkvB09AEUyShbyzoebaKH
 dKtXlzyAPCZoH9dihFM67rhUg4umckFLc8vc5P2tNblwYrnhgL8ymUaOIjZB/fOi
 Z2OZLVCiDeHNjjK3VZ6jLAiPyiYTG1Hrk9E8NaZDeUgIb9X/K06JXVBQIKNSGfX5
 LLp/j2wr+Kbg3QtEBkcStlUGBOzfcbhKpE2nySnuIyspfDb/6JbhD/qYqMJerX0T
 d5ekkJ1tXtM6aX2iTXgZ8cqv+5gyouEF5akrkLi1ySgZetQfjm+zhy/1x/NjGd0u
 35QbUye7sTbfSimwzCXKIIpy06zIO4iNA0P/vgG4v7ydjMvXsW8FRULSecDT19Gq
 xOZGfSPVrSRSAhgNxHzwUivxJbr05NNdwhJSbx9m57naXouLfvVPAMeJYwARAQAB
 tD9GcmVlQlNEIFNlY3VyaXR5IFRlYW0gU2VjcmV0YXJ5IDxzZWN0ZWFtLXNlY3Jl
 dGFyeUBGcmVlQlNELm9yZz6JAj0EEwEKACcFAlJBjIICGwMFCQgH7b8FCwkIBwMF
 FQoJCAsFFgIDAQACHgECF4AACgkQPLLq/MPWxmYt8Q/+IfFhPIbqglh4rwFzgR58
 8YonMZcq+5Op3qiUBh6tE6yRz6VEqBqTahyCQGIk4xGzrHSIOIj2e6gEk5a4zYtf
 0jNJprk3pxu2Og05USJmd8lPSbyBF20FVm5W0dhWMKHagL5dGS8zInlwRYxr6mMi
 UuJjj+2Hm3PoUNGAwL1SH2BVOeAeudtzu80vAlbRlujYVmjIDn/dWVjqnWgEBNHT
 SD+WpA3yW4mBJyxWil0sAJQbTlt5EM/XPORVZ2tvETxJIrXea/Sda9mFwvJ02pJn
 gHi6TGyOYydmbu0ob9Ma9AvUrRlxv8V9eN7eZUtvNa6n+IT8WEJj2+snJlO4SpHL
 D3Z+l7zwfYeM8FOdzGZdVFgxeyBU7t3AnPjYfHmoneqgLcCO0nJDKq/98ohz5T9i
 FbNR/vtLaEiYFBeX3C9Ee96pP6BU26BXhw+dRSnFeyIhD+4g+/AZ0XJ1CPF19D+5
 z0ojanJkh7lZn4JL+V6+mF1eOExiGrydIiiSXDA/p5FhavMMu8Om4S0sn5iaQ2aX
 wRUv2SUKhbHDqhIILLeQKlB3X26obx1Vg0nRhy47qNQn/xc9oSWLAQSVOgsShQeC
 6DSzrKIBdKB3V8uWOmuM7lWAoCP53bDRW+XIOu9wfpSaXN2VTyqzU7zpTq5BHX1a
 +XRw8KNHZGnCSAOCofZWnKyJAhwEEAEKAAYFAlJBjYgACgkQ7Wfs1l3PaudFcQ//
 UiM7EXsIHLwHxez32TzA/0uNMPWFHQN4Ezzg4PKB6Cc4amva5qbgbhoeCPuP+XPI
 2ELfRviAHbmyZ/zIgqplDC4nmyisMoKlpK0Yo1w4qbix9EVVZr2ztL8F43qN3Xe/
 NUSMTBgt/Jio7l5lYyhuVS3JQCfDlYGbq6NPk0xfYoYOMOZASoPhEquCxM5D4D0Z
 3J3CBeAjyVzdF37HUw9rVQe2IRlxGn1YAyMb5EpR2Ij612GFad8c/5ikzDh5q6JD
 tB9ApdvLkr0czTBucDljChSpFJ7ENPjAgZuH9N5Dmx2rRUj2mdBmi7HKqxAN9Kdm
 +pg/6vZ3vM18rBlXmw1poQdc3srAL+6MHmIfHHrq49oksLyHwyeL8T6BO4d4nTZU
 xObP7PLAeWrdrd1Sb3EWlZJ9HB/m2UL9w9Om1c6cb6X2DoCzQAStVypAE6SQCMBK
 pxkWRj90L41BS62snja+BlZTELuuLTHULRkWqS3fFkUxlDSMUn96QksWlwZLcxCv
 hKxJXOX+pHAiUuMIImaPQ0TBDBWWf5d8zOQlNPsyhSGFR5Skwzlg+m9ErQ+jy7Uz
 UmNCNztlYgRKeckXuvr73seoKoNXHrn7vWQ6qB1IRURj2bfphsqlmYuITmcBhfFS
 Dw0fdYXSDXrmG9wad98g49g4HwCJhPAl0j55f93gHLGIRgQQEQoABgUCUkGO5gAK
 CRAV1ogEymzfsol4AKCI7rOnptuoXgwYx2Z9HkUKuugSRwCgkyW9pxa5EovDijEF
 j1jG/cdxTOaJAhwEEAEKAAYFAlJBkdUACgkQkshDRW2mpm6aLxAAzpWNHMZVFt7e
 wQnCJnf/FMLTjduGTEhVFnVCkEtI+YKarveE6pclqKJfSRFDxruZ6PHGG2CDfMig
 J6mdDdmXCkN//TbIlRGowVgsxpIRg4jQVh4S3D0Nz50h+Zb7CHbjp6WAPVoWZz7b
 Myp+pN7qx/miJJwEiw22Eet4Hjj1QymKwjWyY146V928BV/wDBS/xiwfg3xIVPZr
 RqtiOGN/AGpMGeGQKKplkeITY7AXiAd+mL4H/eNf8b+o0Ce2Z9oSxSsGPF3DzMTL
 kIX7sWD3rjy3Xe2BM20stIDrJS2a1fbnIwFvqszS3Z3sF5bLc6W0iyPJdtbQ0pt6
 nekRl9nboAdUs0R+n/6QNYBkj4AcSh3jpZKe82NwnD/6WyzHWtC0SDRTVkcQWXPW
 EaWLmv8VqfzdBiw6aLcxlmXQSAr0cUA6zo6/bMQZosKwiCfGl3tR4Pbwgvbyjoii
 pF+ZXfz7rWWUqZ2C79hy3YTytwIlVMOnp3MyOV+9ubOsFhLuRDxAksIMaRTsO7ii
 5J4z1d+jzWMW4g1B50CoQ8W+FyAfVp/8qGwzvGN7wxN8P1iR+DZjtpCt7J+Xb9Pt
 L+lRKSO/aOgOfDksyt2fEKY4yEWdzq9A3VkRo1HCdUQY6SJ/qt7IyQHumxvL90F6
 vbB3edrR/fVGeJsz4vE10hzy7kI1QT65Ag0EUkGMggEQAMTsvyKEdUsgEehymKz9
 MRn9wiwfHEX5CLmpJAvnX9MITgcsTX8MKiPyrTBnyY/QzA0rh+yyhzkY/y55yxMP
 INdpL5xgJCS1SHyJK85HOdN77uKDCkwHfphlWYGlBPuaXyxkiWYXJTVUggSjuO4b
 jeKwDqFl/4Xc0XeZNgWVjqHtKF91wwgdXXgAzUL1/nwN3IglxiIR31y10GQdOQEG
 4T3ufx6gv73+qbFc0RzgZUQiJykQ3tZK1+Gw6aDirgjQYOc90o2Je0RJHjdObyZQ
 aQc4PTZ2DC7CElFEt2EHJCXLyP/taeLq+IdpKe6sLPckwakqtbqwunWVoPTbgkxo
 Q1eCMzgrkRu23B2TJaY9zbZAFP3cpL65vQAVJVQISqJvDL8K5hvAWJ3vi92qfBcz
 jqydAcbhjkzJUI9t44v63cIXTI0+QyqTQhqkvEJhHZkbb8MYoimebDVxFVtQ3I1p
 EynOYPfn4IMvaItLFbkgZpR/zjHYau5snErR9NC4AOIfNFpxM+fFFJQ7W88JP3cG
 JLl9dcRGERq28PDU/CTDH9rlk1kZ0xzpRDkJijKDnFIxT2ajijVOZx7l2jPL1njx
 s4xa1jK0/39kh6XnrCgK49WQsJM5IflVR2JAi8BLi2q/e0NQG2pgn0QL695Sqbbp
 NbrrJGRcRJD9sUkQTpMsLlQTABEBAAGJAiUEGAEKAA8FAlJBjIICGwwFCQgH7b8A
 CgkQPLLq/MPWxmZAew//et/LToMVR3q6/qP/pf9ob/QwQ3MgejkC0DY3Md7JBRl/
 6GWfySYnO0Vm5IoJofcv1hbhc/y3OeZTvK4s+BOQsNokYe34mCxZG4dypNaepkQi
 x0mLujeU/n4Y0p0LTLjhGLVdKina2dM9HmllgYr4KumT58g6eGjxs2oZD6z5ty0L
 viU5tx3lz3o0c3I9soH2RN2zNHVjXNW0EvWJwFLxFeLJbk/Y3UY1/kXCtcyMzLua
 S5L5012eUOEvaZr5iYDKjy+wOxY4SUCNYf0GPmSej8CBbwHOF2XCwXytSzm6hNb3
 5TRgCGbOSFTIy9MxfV5lpddQcdzijmuFSl8LySkL2yuJxjlI7uKNDN+NlfODIPMg
 rdH0hBSyKci6Uz7Nz/Up3qdE+aISq68k+Hk1fiKJG1UcBRJidheds29FCzj3hoyZ
 VDmf6OL60hL0YI1/4GjIkJyetlPzjMp8J7K3GweOUkfHcFihYZlbiMe7z+oIWEc7
 0fNScrAGF/+JN3L6mjXKB6Pv+ER5ztzpfuhBJ/j7AV5BaNMmDXAVO4aTphWl7Dje
 iecENuGTpkK8Ugv5cMJc4QJaWDkj/9sACc0EFgigPo68KjegvKg5R8jUPwb8E7T6
 lIjBtlclVhaUrE2uLx/yTz2Apbm+GAmD8M0dQ7IYsOFlZNBW9zjgLLCtWDW+p1A=
 =5gJ7
 -----END PGP PUBLIC KEY BLOCK-----

  D.1.3. Core Team Secretary <core-secretary@FreeBSD.org>

 pub   rsa4096/D8C8C83B49F26F17 2020-06-26 [SC] [expires: 2022-06-30]
       Key fingerprint = 4B64 E9E0 BDE9 B3EC C06B  5C66 D8C8 C83B 49F2 6F17
 uid                            FreeBSD Core Team Secretary <core-secretary@freebsd.org>
 sub   rsa4096/377C937536E4821B 2020-06-26 [E] [expires: 2022-06-30]


 -----BEGIN PGP PUBLIC KEY BLOCK-----

 mQINBF72HwABEAC5hl4kfh8DyRpp0WE5rwbnuS+wQ51EVTGs1vLho8OZ2XruzlQT
 AezCnKLsqMgD/UEaBcn9kbKoeqp2sIwuEUX+P79KhRc4C8RJ8TMfDH0OtC091QVp
 MYWbIsvZYCO04K+rN1Dbk2En3BOJVgTowqbZzR3hPvzeU2/P+Y3zMtpQGea2DB5d
 24Q/tIuPMh89evEXOx0K5eM/4P2awSmA3J+h+r09UYjKejJ5OBUJQsMervWAHgCA
 TxJQHoPXw+ZKpJB3dzyHKTMukVZhdCjK6Zt2tih/rO/CHDsitMgYRIl3w2X6pDfV
 JOpvOBlzg7nooIw94v6Uxr2y/JWgOGh2qy07u4qE//y6uSl55s+Vq5TrFr79VSwB
 GhY9As/0Dk1lyFisKp1/yiet2W7Pu4c99Z5dsrQPSTLFvkvonVRX8wgxRZwk6gWA
 LEYklwoR0NXiqlrpBT10Tsnsa4aoUvZW6eyOWZrKsdsVn05sgRmvlfpiqBbwqldJ
 0EeF/MztPuhmq4Hgn+DmmYnx/P85pZpThcfJx16VxS8nB7ExYljeC9LF8V8/1d7e
 tfgAj8ezzNtr2TXSZ5gblQtYLjKdgBiBZqsxHPYHzfG8Zx3eYs2Myklf9p4lt7nv
 atTroDt8pUGXfhGfoqSHSLXODfYAO9/7DOPqTy5Pan4i7aWBPP+gfK0kgQARAQAB
 tDhGcmVlQlNEIENvcmUgVGVhbSBTZWNyZXRhcnkgPGNvcmUtc2VjcmV0YXJ5QGZy
 ZWVic2Qub3JnPokCVAQTAQoAPhYhBEtk6eC96bPswGtcZtjIyDtJ8m8XBQJe9h8A
 AhsDBQkDx60ABQsJCAcDBRUKCQgLBRYDAgEAAh4BAheAAAoJENjIyDtJ8m8XQFwP
 /RqHPMSsLlTcq5NfK2MAVGmdtpL5wf84bchVWtcXUUEwXW1wI2cdDwu9SoqudDbP
 2lrbMpxWeUWAgCpPCF/vCVo4Nzd0zb1cEGKRKFiZe/4EQ8dfvqr03YyupSQvx6+P
 oY+8y3kl7iHJKBkwrASraB2p+N9XDAJDgqz+1M2Xbo7rcJx64wBOCyPAxd9JWsge
 d8mXyAqZlrLihsTjLbhuYbJxpKM5YjGubVaQZaNIDxUduqc8Pt9VgHvWJBc9VPPA
 3B6E9/PUFZYZeZQSROkYniN9NE7keitxj/rvZkpzcaXfAoDMC7CSoLBzlP+CJZ+i
 Kk7IWz4JpxiYkE/IY4VvMMYms9tRP8fVv0+R7r7yKEA9SSlH+e9qC++OoWg4b+wV
 OrWtVIWvaJCtj5ZAPCutGZxBdvXEbHd/Gv6uCzG86n4huz23U+Y4iLzoAlVelnQs
 Hqu1wSAUBNpplyeZ1TvrGg2pufxLh8iXfh0npDP/6J+u0GUfeX4JoAzvxlatXMYI
 fBmqmcZI6ShJN8qQtCUa5OMqbnieo7Fmpf8BsLegjAsQ+8w21ATD2boinStntLzF
 /yoL/z9WYxmoOdHYcQ8bildjCvtbAKrZie8sI4SgWQz2UX6KX9sc/WOmWUEtjdqB
 WfGratZNoxuQLUvEDftt7r9ts1jKVUl3dMPTCfU4wcj5iQIzBBABCgAdFiEEVbCT
 pybDiFVxIrrVNqQMg7DW754FAl72J74ACgkQNqQMg7DW756LaA//Z3CCF5fQ08tx
 RLeqHNsS5xCYS97TjZxY6xAMBjebkS+ABkgdbedSH+YNGfdaGSD/SMtvMAmnx55t
 18DDdA4pqC5x2USaHjXFdbDdxKuKMAoSAtOpipVASVmW0FkZI5C5FDe3MF8+mfGb
 EPhVPwKbo7R5tk4jUPyX8wUaOAyUX9fyQnwDxN+zTHvKwnX/+qwpoKaY2N4ZOI0w
 rOF1kkczibbfwvjVYcpPovGALmTccnWo1Xvpkhllg93Y21mH+T2Ub/BK3GhvgJQi
 WwiDtMwelUnPLp4W1451OU1OyGzeT/XwuMPH9dsKz5Iw4/g1zqQEtZj2Gc0DP5we
 HM50doTn+dVIF+WCFLhPYm0RSf8Zj8ngbX/HV2UYLB5k+uNT9YTnBVEdKVydx7Cp
 IplC7XApJEfTUk7wl7YCGn5P5YolC7DSJlwcAjxdbffXLowBhgyOq+EJJgnqerZl
 r4db58h2epIHRKgnSl5z4KoAGW1O5dFShBz1UYPj4cZdeE+twpcgEg3/7LMzPzF/
 xQAQZ89axxXBaCPl+YVsuMJSerbNdPp1SjCs9e8Vev91tLFmt/sY4IpvbPHZavGl
 /4ealh8E1zPgf8lVW9TPrUY6mjN/uDI2y39tk2EoFzOcSQhlEM6gRW8uV4q92cWM
 V55hu7Vs2RrKA7fve9y+YBi3DdTwwHSJATMEEAEKAB0WIQSfAoNvUNOtWrdaxYgM
 tAPk6VuW7AUCXvY98wAKCRAMtAPk6VuW7CDLB/9PSUSMV/pnC+X4ougpjpqfSJf8
 5bozjkKSkNqXZmt2vJVImc/oSK13awq46FC4rAhk59lT3kaH6EKvDHQ5G8Twi07u
 VotcOdtfMjXgPV6RLmo6Hps0E1nzmbsum6xeemRDf3D3n1kAdUteXNBxHTIdAbeY
 p4Wxu46CC/SqD6HbnUF2o+/6dXXyV1lTnViIj6m5eFD2OQ4Jdq7GPsSjSS2XL4f9
 jHZUOUJyyA0aFWjJ+SCzMkXSUnyiOCl4uUHdCgivLIRyZ/giWoQpr8sAgHXCh82h
 T3BmbHgmcMgMh+wNxH878IPwUU0CKRd2dL5kOSZVCFuMnFsc9eIie5kMEJwPuQIN
 BF72HwABEADT9l4GIYiFaYg2QbQ3wsmmFnP/pAZiHDxXI6wL6xCKj6o2sc1/b5j3
 ILEiAoqZ5ZenXX6T7Epjal0ASkfsGo/n3vF18grSudIkXJPQXcb61fXU7xfmGAEU
 HWABQG+OD/HTvUPAITVckl4LxVFkz3oqRnq13rxDk1XZYvLVWeBn8vfWF4/glz9k
 etfLw71Pk9f86BuNb0vCPnWpOpZaOxKlabdGpMKDD+1RYC/L+ZEwKiLBfgXTzK3g
 IWAX3kTrQjKBZzsQ0s5TFWkm+z80GVUq8HKlXUOuF8s7cX+KXGU2kYcC8DQrxPdL
 jYm6N8axOn4RR8eP5ZFA0W7qMieFSHAjqCs4srdN1bGC3nS0zGsQCvtTRBbu0nen
 O6uwzWQgTzWVfV+dqaEH2crnhn5CUI0A8jdbFBGDiBbWJz/QfRray1CEc8q+hZFM
 OLBsVXrDVe6hUXTveGc9xAnXC+0o3nnc7WhWr1caTbbhnzlEbME8u2oLif7rkhc7
 FanuQEyKa76J1zou08ZeLK/pUFXTbRCoyUEVL+VIxLESCWi1ptkDpiZey3l6fe0Q
 WWRMLFMpbu3WTNl21bEwfRL03+fP1q+yGAV5hyJv/EMldd76v577dAolIsTh+aDP
 PMJ7mJ5NwOuiC20HIlCjuVT5A2pBIzFfraZY/v4dzoaOpXZjEz9wIwARAQABiQI8
 BBgBCgAmFiEES2Tp4L3ps+zAa1xm2MjIO0nybxcFAl72HwACGwwFCQPHrQAACgkQ
 2MjIO0nybxcflQ/9FYvM/lBSzy4VFOjNsUkRtjmPtyw2dJmQOCbWoSHmibRCG26a
 Upt5lp1n4LG/qEtDlus5mDETL+/TnYhCG+hhnHADc87goLwBwl37yK1NAYvOy2rm
 TddjDT5vZW0yzHjHqIJlNxQ4OjMi/XjyHIzb0PGNayFVi3XkLVxWZI+lWON1btWk
 gpFfEgqRqQbJxM2cSEQimkfrrE+b2/M4cGX9rThpTtpfpbyHjTsS6juo4/eIdnBA
 UXpKce4Q9LB5zxDaakKoDVxxkc9R0HAAoIH4u+Fu8az+CuH2sJcVJWK7Nxct++N8
 Xhj+FUS+Ay8siu+ScQjsOHOHRwr6a+6NT58eylwR5hwotmnzJHLZReqknoAjLEGT
 d33jzKM/y6OqPe/oPGj2b13RkA2vRnCPm33+T57sLMonNe6hhlXs9VTgXxSAzfMa
 cmVOdP+nxUsoc3MtqjE2z2BcI9WMmmJFeEgE2BOj703CQuot+8jcZFXGUW+i6V1a
 k7dZEMDsbALNzxaRNGeJC6HiM1+dXFGLNHEIgBLGwdvFAxTfNauvK0p7skDWEx44
 giaUjZYpQ21+SHjVKTUnFQiiIDORvs3jdZDaxK/Y/vSoLRUiLBiHZWa6mxQY4uc6
 5nAzLZB2BiBRfdL8fEO154nWjAZBLbKhK+ke2DBoPvSWubLPJqZyh+GmZAE=
 =3AI7
 -----END PGP PUBLIC KEY BLOCK-----

  D.1.4. Ports Management Team Secretary <portmgr-secretary@FreeBSD.org>

 pub   rsa2048/D8294EC3BBC4D7D5 2012-07-24 [SC]
       Key fingerprint = FB37 45C8 6F15 E8ED AC81  32FC D829 4EC3 BBC4 D7D5
 uid                            FreeBSD Ports Management Team Secretary <portmgr-secretary@FreeBSD.org>
 sub   rsa2048/5CC117965F65CFE7 2012-07-24 [E]


 -----BEGIN PGP PUBLIC KEY BLOCK-----

 mQENBFAOzqYBCACYd+KGv0/DduIRpSEKWZG2yfDILStzWfdaQMD+8zdWihB0x7dd
 JDBUpV0o0Ixzt9mvu5CHybx+9lOHeFRhZshFXc+bIJOPyi+JrSs100o7Lo6jg6+c
 Si2vME0ixG4x9YjCi8DisXIGJ1kZiDXhmVWwCvL+vLInpeXrtJnK8yFkmszCOr4Y
 Q3GXuvdU0BF2tL/Wo/eCbSf+3U9syopVS2L2wKcP76bbYU0ioO35Y503rJEK6R5G
 TchwYvYjSXuhv4ec7N1/j3thrMC9GNpoqjVninTynOk2kn+YZuMpO3c6b/pfoNcq
 MxoizGlTu8VT4OO/SF1y52OkKjpAsENbFaNTABEBAAG0R0ZyZWVCU0QgUG9ydHMg
 TWFuYWdlbWVudCBUZWFtIFNlY3JldGFyeSA8cG9ydG1nci1zZWNyZXRhcnlARnJl
 ZUJTRC5vcmc+iQE4BBMBAgAiBQJQDs6mAhsDBgsJCAcDAgYVCAIJCgsEFgIDAQIe
 AQIXgAAKCRDYKU7Du8TX1QW2B/0coHe8utbTfGKpeM4BY9IyC+PFgkE58Hq50o8d
 shoB9gfommcUaK9PNwJPxTEJNlwiKPZy+VoKs/+dO8gahovchbRdSyP1ejn3CFy+
 H8pol0hDDU4n7Ldc50q54GLuZijdcJZqlgOloZqWOYtXFklKPZjdUvYN8KHAntgf
 u361rwM4DZ40HngYY9fdGc4SbXurGA5m+vLAURLzPv+QRQqHfaI1DZF6gzMgY49x
 qS1JBF4kPoicpgvs3o6CuX8MD9ewGFSAMM3EdzV6ZdC8pnpXC8+8Q+p6FjNqmtjk
 GpW39Zq/p8SJVg1RortCH6qWLe7dW7TaFYov7gF1V/DYwDN5iEYEEBECAAYFAlN2
 WksACgkQtzkaJjSHbFtuMwCg0MXdQTcGMMOma7LC3L5b4MEoZ+wAn0WyUHpHwHnn
 pn2oYDlfAbwTloWIiQEcBBABAgAGBQJQDuVrAAoJENk3EJekc8mQ3KwIAImNDMXA
 F8ajPwCZFpM6KDi3F/jpwyBPISGY1oWuYPEi1zN94k5jS90aZb3W8Y8x4JTh35Ew
 b6XODi3uGLSLCmnlqu2a80yPfXf5IuWmIQdFNQxvosj9UHrg+icZGFmm+f0hPJxM
 TsZREv3AvivQfnb/N3xIICxW4SjKSYXQcq4hr4ObhUx7GKnjayq+ofU2cRlujr87
 uOH0fO3xhOJG4+cX5mI1HGK38k0Csc1zqYa/66Qe5dnIZz+sNXpEPMLAHIt1a45U
 B967igJdZSDFN33bPl1QWmf3aUXU3d1VttiSyHkpm4kb9KgsDkUk1IJ5nUe9OXyd
 WtoqNW5afDa5N0aIRgQQEQIABgUCUA7lwwAKCRB59uBxdBRinNh2AJ41+zfsaQSR
 HWvSkqOXGcP/fgOduwCfUJDT+M1eXe2udmKof/9yzGYMirKJASIEEAECAAwFAlAa
 IT8FAwASdQAACgkQlxC4m8pXrXwCHAf+J7l+L7AvRpqlQcezjnjFS/zG1098qkDf
 lThHZlpVnrBMJZaXdvL6LzVgiIYVWZC5CSSazW9EWFjp9VjM7FBHdWFZNMV7GAuU
 t0jzx6gGXOWwi+/v/hs1P11RyDZN5hICHdPNmyZVupciDxe+sIEP9aEbVxcaiccq
 zM/pFzIVIMMP5tCiA42q6Mz3h0hy6hntUKptS8Uon6sje5cDVcVlKAUj1wO2cphC
 qkYlwMQfZV5J9f/hcW5ODriD3cBwK8SocA2Cq5JYF8kYDL1+pXnUutGnvAHUYt87
 RWvQdKmfXjzBcMFJ2LlPUB1+IFvwQ13V9R8j9B/EdLmSWQYT9qRA2okCHAQTAQoA
 BgUCV1XMpwAKCRCtu/hhCjeJt2CyD/9JLe+Ck23CJkeRSF8oC+4SFOUdSAmejSzn
 klPwmEClffABYd/kckO1T6um+2FUcXuJZQE1nKKUNvZ8pBWwsm1RDHsyroKi/XB1
 0a1Tdx/rvlU88ytbeLfUCLzoCrf6pkMQWoU6/3qS6elV0WwOlDufk+XjD1sja2wu
 sshG8y+1WCA5JjP3rZdD9NVdzo5DgkotTRUfuYN1LJIN4zlDgHj7FVP7wW7+R0cZ
 FoOiNsLJCA0FN8SiyU98UysjawLiIY9dTJz6XVA0DgB0TZWO3mWiDjITeKrdGcqf
 PNiJhmvUKBkn07YpTPNfkoTT/p/q5ChYmu0ubGeyS1ELKjmklJ+DzynfZLzvnXYX
 Ngo5ckeuqEqUNxM0J63v8lmfhDRROFveqHWdp0XMxXVmR5bMunSldg5EZsoLyQbN
 +ScIPnDTAEPGrCtf0t84RQxNQeET6/WBbZfzeSeAFmpBFCdicsZ6Mjwtwjr4+o15
 n1QMTZco1NaTqf8vXwzl9wM4aYtg1OkF4z8HdHuy50CHCet4mT5eJgwZUfFvXdbM
 pHXprEI0Y9OOL4aMinC1egF3dXt/0n57i6CE+E2k3UJPNvMrtp0HaDEnKZ8cfkBU
 EBzkUYi5wwqntHV2JRisqoRnHdvJT7ImlHMe7WaJsifBK874PnToaKg8P6K1Tph+
 FyLxULaYjYkCHAQSAQgABgUCVBg2zwAKCRDqsDxYv9xHj1klEADXYJdHC3zsdx7w
 DsJsttWdykcZoOd/VUKUdN0BAU72nLV0tLn4uFjETA6MhHZVxzwIDTeLB8kqyEpc
 fZnoVbqJIUJz1sJXMdOty7CwZzlZlAwmUaIfFiazJY1p398JbyYfSrVKNOpw9wCm
 Db7WP9dBritwvjaLzu8HQsiztO0S/5ha/EDfTU3qocBUTjbCtGR9LqAmPE4X8+li
 F2EfZMEoJd3rJWsYv2y/k6pSgC/MpQewnyr6f+JQ/781UoZB6PpxCxfu4D6xlOyd
 ERBUg+FfDAWYR+KX+DGOalRlUyaSz8Nvxl8/b0Im/AQhx9afqyEZxIDpg52zt8jJ
 t3wx23YP8EQGUgwF8pIrj3wFSBSG3a/cskiBNUIhChIR9hQrVPUahN/jx7DGAGxk
 /Ka9qsRGYTHfSr9jjTUQ+htfeFBRDR0nkZKMo5+Wk/cAcBKVbPlBpwvnzT3fh+wL
 cF3ErBbx5jp+BoFee8D6ATeUvQxMcgVbDPUkgMsy3EtKMVO10jhIoXoVV+Sg9GZ8
 zMEy1tORKn0zsd2ZgXC2sRJOm5ttCSdYQ4ddbM1A9jg6tiRx4hES16GDywvkL8P2
 M9+qyIfjQxjGU33f/r8zp9DyNT1VlrtwhFxtOoMdmrsbYOCTja4Xg14hK1hRac0k
 GB7bj6w97p8uMrQT3PlSMtoyrRyo7bkBDQRQDs6mAQgAzNxJYpf5PrqV8pdRXkn3
 6Fe45q671YtbZ2WrT7D0CVZ8Z+AZsxnP/tiY1SrM2MepCeA2xBAhKGsWBWo1aRk5
 mfZOksKsiXsi2XeBVhdZlCkrOMKBTVian7I1lH59ZnNIMX0Nl0tlj3L1IjeWWNvf
 ej43URV81S9EmSwpjaWboatr2A+1oJku5m7nPD9JIOckE1TzBsyhx7zIUN9w6MKr
 7gFw8DCzypwUKyYgKYToVm8QlkT/L3B0fuQHWhT6ROGk4o8SC71ia5tc1TzUzGEZ
 1AQO8bbnbmJLBDKveWHCoaeAkRzINzoD9wAn9z4pnilze59QtKC1cOqUksTvBSDh
 6wARAQABiQEfBBgBAgAJBQJQDs6mAhsMAAoJENgpTsO7xNfVOHoH/i5VyggVdwpq
 PX8YBmN5mXQziYZNQoiON8IhOsxpX4W2nXCj5m6MACV6nJDVV6wyUH8/VvDQC9nH
 arCe1oaNsHXJz0HamYt5gHJ0G1bYuBcuJp/FEjLa48XFI7nXQjJHn8rlwZMjK/PW
 j1lw2WZiekviuzTEDH8c3YStGJSa+gYe8Eyq3XJVAe2VQOhImoWgGDR3tWfgrya/
 IdEFb/jmjHSG5XUfbI0vNwqlf832BqSQKPG/Zix4MmBJgvAz4R71PH8WBmbmNFjD
 elxVyfz80+iMgEb9aL91MfeBNC2KB1pFmg91mQTsiq7ajwVLVJK8NplHAkdLmkBC
 O8MgMjzGhlE=
 =iw7d
 -----END PGP PUBLIC KEY BLOCK-----

  D.1.5. <doceng-secretary@FreeBSD.org>

 pub   rsa2048/E1C03580AEB45E58 2019-10-31 [SC] [expires: 2022-10-30]
       Key fingerprint = F24D 7B32 B864 625E 5541  A0E4 E1C0 3580 AEB4 5E58
 uid                            FreeBSD Doceng Team Secretary <doceng-secretary@freebsd.org>
 sub   rsa2048/9EA8D713509472FC 2019-10-31 [E] [expires: 2022-10-30]


 -----BEGIN PGP PUBLIC KEY BLOCK-----

 mQENBF27FFcBCADeoSsIgyQUY8vREwkTikwFFlNg31MVy5s/Nq1cNK1PRfRMnprS
 yfB62KqbYuz16bmQKaA9zHN4FGfiTvR6tl66LVHm1s/5HPiLv8sP14GsruLro9zN
 v72dO7a9i68bMw+jarPOnu9dGiDFEI0dACOkdCGEYKEUapQeNpmWRrQ46BeXyFwF
 JcNx76bJJUkwk6fWC0W63D762e6lCEX6ndoaPjjLBnFvtx13heNGUc8RukBwe2mA
 U5pSGHj47J05bdWiRSwZaXa8PcW+20zTWaP755w7zWe4h60GANY7OsT9nuOqsioJ
 QonxTrJuZweKRV8fNQ1EfDws3HZr7/7iXvO3ABEBAAG0PEZyZWVCU0QgRG9jZW5n
 IFRlYW0gU2VjcmV0YXJ5IDxkb2Nlbmctc2VjcmV0YXJ5QGZyZWVic2Qub3JnPokB
 VAQTAQoAPhYhBPJNezK4ZGJeVUGg5OHANYCutF5YBQJduxRXAhsDBQkFo5qABQsJ
 CAcDBRUKCQgLBRYDAgEAAh4BAheAAAoJEOHANYCutF5YB2IIALw+EPYmOz9qlqIn
 oTFmk/5MrcdzC5iLEfxubbF6TopDWsWPiOh5mAuvfEmROSGf6ctvdYe9UtQV3VNY
 KeeyskeFrIBOFo2KG/dFqKPAWef6IfhbW3HWDWo5uOBg01jHzQ/pB1n6SMKiXfsM
 idL9wN+UQKxF3Y7S/bVrZTV0isRUolO9+8kQeSYT/NMojVM0H2fWrTP/TaNEW4fY
 JBDAl5hsktzdl8sdbNqdC0GiX3xb4GvgVzGGQELagsxjfuXk6PfOyn6Wx2d+yRcI
 FrKojmhihBp5VGFQkntBIXQkaW0xhW+WBGxwXdaAl0drQlZ3W+edgdOl705x73kf
 Uw3Fh2a5AQ0EXbsUVwEIANEPAsltM4vFj2pi5xEuHEcZIrIX/ZJhoaBtZkqvkB+H
 4pu3/eQHK5hg0Dw12ugffPMz8mi57iGNI9TXd8ZYMJxAdvEZSDHCKZTX9G+FcxWa
 /AzKNiG25uSISzz7rMB/lV1gofCdGtpHFRFTiNxFcoacugTdlYDiscgJZMJSg/hC
 GXBdEKXR5WRAgAGandcL8llCToOt1lZEOkd5vJM861w6evgDhAZ2HGhRuG8/NDxG
 r4UtlnYGUCFof/Q4oPNbDJzmZXF+8OQyTNcEpVD3leEOWG1Uv5XWS2XKVHcHZZ++
 ISo/B5Q6Oi3SJFCVV9f+g09YF+PgfP/mVMBgif2fT20AEQEAAYkBPAQYAQoAJhYh
 BPJNezK4ZGJeVUGg5OHANYCutF5YBQJduxRXAhsMBQkFo5qAAAoJEOHANYCutF5Y
 kecIAMTh2VHQqjXHTszQMsy3NjiTVVITI3z+pzY0u2EYmLytXQ2pZMzLHMcklmub
 5po0X4EvL6bZiJcLMI2mSrOs0Gp8P3hyMI40IkqoLMp7VA2LFlPgIJ7K5W4oVwf8
 khY6lw7qg2l69APm/MM3xAyiL4p6MU8tpvWg5AncZ6lxyy27rxVflzEtCrKQuG/a
 oVaOlMjH3uxvOK6IIxlhvWD0nKs/e2h2HIAZ+ILE6ytS5ZEg2GXuigoQZdEnv71L
 xyvE9JANwGZLkDxnS5pgN2ikfkQYlFpJEkrNTQleCOHIIIp8vgJngEaP51xOIbQM
 CiG/y3cmKQ/ZfH7BBvlZVtZKQsI=
 =MQKT
 -----END PGP PUBLIC KEY BLOCK-----

                                FreeBSD Glossary

   This glossary contains terms and acronyms used within the FreeBSD
   community and documentation.

  A

   ACL

           See Access Control List.

   ACPI

           See Advanced Configuration and Power Interface.

   AMD

           See Automatic Mount Daemon.

   AML

           See ACPI Machine Language.

   API

           See Application Programming Interface.

   APIC

           See Advanced Programmable Interrupt Controller.

   APM

           See Advanced Power Management.

   APOP

           See Authenticated Post Office Protocol.

   ASL

           See ACPI Source Language.

   ATA

           See Advanced Technology Attachment.

   ATM

           See Asynchronous Transfer Mode.

   ACPI Machine Language

           Pseudocode, interpreted by a virtual machine within an
           ACPI-compliant operating system, providing a layer between the
           underlying hardware and the documented interface presented to the
           OS.

   ACPI Source Language

           The programming language AML is written in.

   Access Control List

           A list of permissions attached to an object, usually either a file
           or a network device.

   Advanced Configuration and Power Interface

           A specification which provides an abstraction of the interface the
           hardware presents to the operating system, so that the operating
           system should need to know nothing about the underlying hardware
           to make the most of it. ACPI evolves and supersedes the
           functionality provided previously by APM, PNPBIOS and other
           technologies, and provides facilities for controlling power
           consumption, machine suspension, device enabling and disabling,
           etc.

   Application Programming Interface

           A set of procedures, protocols and tools that specify the
           canonical interaction of one or more program parts; how, when and
           why they do work together, and what data they share or operate on.

   Advanced Power Management

           An API enabling the operating system to work in conjunction with
           the BIOS in order to achieve power management. APM has been
           superseded by the much more generic and powerful ACPI
           specification for most applications.

   Advanced Programmable Interrupt Controller

   Advanced Technology Attachment

   Asynchronous Transfer Mode

   Authenticated Post Office Protocol

   Automatic Mount Daemon

           A daemon that automatically mounts a filesystem when a file or
           directory within that filesystem is accessed.

  B

   BAR

           See Base Address Register.

   BIND

           See Berkeley Internet Name Domain.

   BIOS

           See Basic Input/Output System.

   BSD

           See Berkeley Software Distribution.

   Base Address Register

           The registers that determine which address range a PCI device will
           respond to.

   Basic Input/Output System

           The definition of BIOS depends a bit on the context. Some people
           refer to it as the ROM chip with a basic set of routines to
           provide an interface between software and hardware. Others refer
           to it as the set of routines contained in the chip that help in
           bootstrapping the system. Some might also refer to it as the
           screen used to configure the bootstrapping process. The BIOS is
           PC-specific but other systems have something similar.

   Berkeley Internet Name Domain

           An implementation of the DNS protocols.

   Berkeley Software Distribution

           This is the name that the Computer Systems Research Group (CSRG)
           at The University of California at Berkeley gave to their
           improvements and modifications to AT&T's 32V UNIX(R). FreeBSD is a
           descendant of the CSRG work.

   Bikeshed Building

           A phenomenon whereby many people will give an opinion on an
           uncomplicated topic, whilst a complex topic receives little or no
           discussion. See the FAQ for the origin of the term.

  C

   CD

           See Carrier Detect.

   CHAP

           See Challenge Handshake Authentication Protocol.

   CLIP

           See Classical IP over ATM.

   COFF

           See Common Object File Format.

   CPU

           See Central Processing Unit.

   CTS

           See Clear To Send.

   Carrier Detect

           An RS232C signal indicating that a carrier has been detected.

   Central Processing Unit

           Also known as the processor. This is the brain of the computer
           where all calculations take place. There are a number of different
           architectures with different instruction sets. Among the more
           well-known are the Intel-x86 and derivatives, Arm, and PowerPC.

   Challenge Handshake Authentication Protocol

           A method of authenticating a user, based on a secret shared
           between client and server.

   Classical IP over ATM

   Clear To Send

           An RS232C signal giving the remote system permission to send data.

           See Also Request To Send.

   Common Object File Format

  D

   DAC

           See Discretionary Access Control.

   DDB

           See Debugger.

   DES

           See Data Encryption Standard.

   DHCP

           See Dynamic Host Configuration Protocol.

   DNS

           See Domain Name System.

   DSDT

           See Differentiated System Description Table.

   DSR

           See Data Set Ready.

   DTR

           See Data Terminal Ready.

   DVMRP

           See Distance-Vector Multicast Routing Protocol.

   Discretionary Access Control

   Data Encryption Standard

           A method of encrypting information, traditionally used as the
           method of encryption for UNIX(R) passwords and the crypt(3)
           function.

   Data Set Ready

           An RS232C signal sent from the modem to the computer or terminal
           indicating a readiness to send and receive data.

           See Also Data Terminal Ready.

   Data Terminal Ready

           An RS232C signal sent from the computer or terminal to the modem
           indicating a readiness to send and receive data.

   Debugger

           An interactive in-kernel facility for examining the status of a
           system, often used after a system has crashed to establish the
           events surrounding the failure.

   Differentiated System Description Table

           An ACPI table, supplying basic configuration information about the
           base system.

   Distance-Vector Multicast Routing Protocol

   Domain Name System

           The system that converts humanly readable hostnames (i.e.,
           mail.example.net) to Internet addresses and vice versa.

   Dynamic Host Configuration Protocol

           A protocol that dynamically assigns IP addresses to a computer
           (host) when it requests one from the server. The address
           assignment is called a "lease".

  E

   ECOFF

           See Extended COFF.

   ELF

           See Executable and Linking Format.

   ESP

           See Encapsulated Security Payload.

   Encapsulated Security Payload

   Executable and Linking Format

   Extended COFF

  F

   FADT

           See Fixed ACPI Description Table.

   FAT

           See File Allocation Table.

   FAT16

           See File Allocation Table (16-bit).

   FTP

           See File Transfer Protocol.

   File Allocation Table

   File Allocation Table (16-bit)

   File Transfer Protocol

           A member of the family of high-level protocols implemented on top
           of TCP which can be used to transfer files over a TCP/IP network.

   Fixed ACPI Description Table

  G

   GUI

           See Graphical User Interface.

   Giant

           The name of a mutual exclusion mechanism (a sleep mutex) that
           protects a large set of kernel resources. Although a simple
           locking mechanism was adequate in the days where a machine might
           have only a few dozen processes, one networking card, and
           certainly only one processor, in current times it is an
           unacceptable performance bottleneck. FreeBSD developers are
           actively working to replace it with locks that protect individual
           resources, which will allow a much greater degree of parallelism
           for both single-processor and multi-processor machines.

   Graphical User Interface

           A system where the user and computer interact with graphics.

  H

   HTML

           See HyperText Markup Language.

   HUP

           See HangUp.

   HangUp

   HyperText Markup Language

           The markup language used to create web pages.

  I

   I/O

           See Input/Output.

   IASL

           See Intel's ASL compiler.

   IMAP

           See Internet Message Access Protocol.

   IP

           See Internet Protocol.

   IPFW

           See IP Firewall.

   IPP

           See Internet Printing Protocol.

   IPv4

           See IP Version 4.

   IPv6

           See IP Version 6.

   ISP

           See Internet Service Provider.

   IP Firewall

   IP Version 4

           The IP protocol version 4, which uses 32 bits for addressing. This
           version is still the most widely used, but it is slowly being
           replaced with IPv6.

           See Also IP Version 6.

   IP Version 6

           The new IP protocol. Invented because the address space in IPv4 is
           running out. Uses 128 bits for addressing.

   Input/Output

   Intel's ASL compiler

           Intel's compiler for converting ASL into AML.

   Internet Message Access Protocol

           A protocol for accessing email messages on a mail server,
           characterised by the messages usually being kept on the server as
           opposed to being downloaded to the mail reader client.

           See Also Post Office Protocol Version 3.

   Internet Printing Protocol

   Internet Protocol

           The packet transmitting protocol that is the basic protocol on the
           Internet. Originally developed at the U.S. Department of Defense
           and an extremely important part of the TCP/IP stack. Without the
           Internet Protocol, the Internet would not have become what it is
           today. For more information, see RFC 791.

   Internet Service Provider

           A company that provides access to the Internet.

  K

   KAME

           Japanese for "turtle", the term KAME is used in computing circles
           to refer to the KAME Project, who work on an implementation of
           IPv6.

   KDC

           See Key Distribution Center.

   KLD

           See Kernel ld(1).

   KSE

           See Kernel Scheduler Entities.

   KVA

           See Kernel Virtual Address.

   Kbps

           See Kilo Bits Per Second.

   Kernel ld(1)

           A method of dynamically loading functionality into a FreeBSD
           kernel without rebooting the system.

   Kernel Scheduler Entities

           A kernel-supported threading system. See the project home page for
           further details.

   Kernel Virtual Address

   Key Distribution Center

   Kilo Bits Per Second

           Used to measure bandwidth (how much data can pass a given point at
           a specified amount of time). Alternates to the Kilo prefix include
           Mega, Giga, Tera, and so forth.

  L

   LAN

           See Local Area Network.

   LOR

           See Lock Order Reversal.

   LPD

           See Line Printer Daemon.

   Line Printer Daemon

   Local Area Network

           A network used on a local area, e.g. office, home, or so forth.

   Lock Order Reversal

           The FreeBSD kernel uses a number of resource locks to arbitrate
           contention for those resources. A run-time lock diagnostic system
           found in FreeBSD-CURRENT kernels (but removed for releases),
           called witness(4), detects the potential for deadlocks due to
           locking errors. (witness(4) is actually slightly conservative, so
           it is possible to get false positives.) A true positive report
           indicates that "if you were unlucky, a deadlock would have
           happened here".

           True positive LORs tend to get fixed quickly, so check
           http://lists.FreeBSD.org/mailman/listinfo/freebsd-current and the
           LORs Seen page before posting to the mailing lists.

  M

   MAC

           See Mandatory Access Control.

   MADT

           See Multiple APIC Description Table.

   MFC

           See Merge From Current.

   MFH

           See Merge From Head.

   MFS

           See Merge From Stable.

   MFV

           See Merge From Vendor.

   MIT

           See Massachusetts Institute of Technology.

   MLS

           See Multi-Level Security.

   MOTD

           See Message Of The Day.

   MTA

           See Mail Transfer Agent.

   MUA

           See Mail User Agent.

   Mail Transfer Agent

           An application used to transfer email. An MTA has traditionally
           been part of the BSD base system. Today Sendmail is included in
           the base system, but there are many other MTAs, such as postfix,
           qmail and Exim.

   Mail User Agent

           An application used by users to display and write email.

   Mandatory Access Control

   Massachusetts Institute of Technology

   Merge From Current

           To merge functionality or a patch from the -CURRENT branch to
           another, most often -STABLE.

   Merge From Head

           To merge functionality or a patch from a repository HEAD to an
           earlier branch.

   Merge From Stable

           In the normal course of FreeBSD development, a change will be
           committed to the -CURRENT branch for testing before being merged
           to -STABLE. On rare occasions, a change will go into -STABLE first
           and then be merged to -CURRENT.

           This term is also used when a patch is merged from -STABLE to a
           security branch.

           See Also Merge From Current.

   Merge From Vendor

   Message Of The Day

           A message, usually shown on login, often used to distribute
           information to users of the system.

   Multi-Level Security

   Multiple APIC Description Table

  N

   NAT

           See Network Address Translation.

   NDISulator

           See Project Evil.

   NFS

           See Network File System.

   NTFS

           See New Technology File System.

   NTP

           See Network Time Protocol.

   Network Address Translation

           A technique where IP packets are rewritten on the way through a
           gateway, enabling many machines behind the gateway to effectively
           share a single IP address.

   Network File System

   New Technology File System

           A filesystem developed by Microsoft and available in its "New
           Technology" operating systems, such as Windows(R) 2000,
           Windows NT(R) and Windows(R) XP.

   Network Time Protocol

           A means of synchronizing clocks over a network.

  O

   OBE

           See Overtaken By Events.

   ODMR

           See On-Demand Mail Relay.

   OS

           See Operating System.

   On-Demand Mail Relay

   Operating System

           A set of programs, libraries and tools that provide access to the
           hardware resources of a computer. Operating systems range today
           from simplistic designs that support only one program running at a
           time, accessing only one device to fully multi-user, multi-tasking
           and multi-process systems that can serve thousands of users
           simultaneously, each of them running dozens of different
           applications.

   Overtaken By Events

           Indicates a suggested change (such as a Problem Report or a
           feature request) which is no longer relevant or applicable due to
           such things as later changes to FreeBSD, changes in networking
           standards, the affected hardware having since become obsolete, and
           so forth.

  P

   PAE

           See Physical Address Extensions.

   PAM

           See Pluggable Authentication Modules.

   PAP

           See Password Authentication Protocol.

   PC

           See Personal Computer.

   PCNSFD

           See Personal Computer Network File System Daemon.

   PDF

           See Portable Document Format.

   PID

           See Process ID.

   POLA

           See Principle Of Least Astonishment.

   POP

           See Post Office Protocol.

   POP3

           See Post Office Protocol Version 3.

   PPD

           See PostScript Printer Description.

   PPP

           See Point-to-Point Protocol.

   PPPoA

           See PPP over ATM.

   PPPoE

           See PPP over Ethernet.

   PPP over ATM

   PPP over Ethernet

   PR

           See Problem Report.

   PXE

           See Preboot eXecution Environment.

   Password Authentication Protocol

   Personal Computer

   Personal Computer Network File System Daemon

   Physical Address Extensions

           A method of enabling access to up to 64 GB of RAM on systems which
           only physically have a 32-bit wide address space (and would
           therefore be limited to 4 GB without PAE).

   Pluggable Authentication Modules

   Point-to-Point Protocol

   Pointy Hat

           A mythical piece of headgear, much like a dunce cap, awarded to
           any FreeBSD committer who breaks the build, makes revision numbers
           go backwards, or creates any other kind of havoc in the source
           base. Any committer worth his or her salt will soon accumulate a
           large collection. The usage is (almost always?) humorous.

   Portable Document Format

   Post Office Protocol

           See Also Post Office Protocol Version 3.

   Post Office Protocol Version 3

           A protocol for accessing email messages on a mail server,
           characterised by the messages usually being downloaded from the
           server to the client, as opposed to remaining on the server.

           See Also Internet Message Access Protocol.

   PostScript Printer Description

   Preboot eXecution Environment

   Principle Of Least Astonishment

           As FreeBSD evolves, changes visible to the user should be kept as
           unsurprising as possible. For example, arbitrarily rearranging
           system startup variables in /etc/defaults/rc.conf violates POLA.
           Developers consider POLA when contemplating user-visible system
           changes.

   Problem Report

           A description of some kind of problem that has been found in
           either the FreeBSD source or documentation. See Writing FreeBSD
           Problem Reports.

   Process ID

           A number, unique to a particular process on a system, which
           identifies it and allows actions to be taken against it.

   Project Evil

           The working title for the NDISulator, written by Bill Paul, who
           named it referring to how awful it is (from a philosophical
           standpoint) to need to have something like this in the first
           place. The NDISulator is a special compatibility module to allow
           Microsoft Windows(TM) NDIS miniport network drivers to be used
           with FreeBSD/i386. This is usually the only way to use cards where
           the driver is closed-source. See src/sys/compat/ndis/subr_ndis.c.

  R

   RA

           See Router Advertisement.

   RAID

           See Redundant Array of Inexpensive Disks.

   RAM

           See Random Access Memory.

   RD

           See Received Data.

   RFC

           See Request For Comments.

   RISC

           See Reduced Instruction Set Computer.

   RPC

           See Remote Procedure Call.

   RS232C

           See Recommended Standard 232C.

   RTS

           See Request To Send.

   Random Access Memory

   Revision Control System

           The Revision Control System (RCS) is one of the oldest software
           suites that implement "revision control" for plain files. It
           allows the storage, retrieval, archival, logging, identification
           and merging of multiple revisions for each file. RCS consists of
           many small tools that work together. It lacks some of the features
           found in more modern revision control systems, like Git, but it is
           very simple to install, configure, and start using for a small set
           of files.

           See Also Subversion.

   Received Data

           An RS232C pin or wire that data is received on.

           See Also Transmitted Data.

   Recommended Standard 232C

           A standard for communications between serial devices.

   Reduced Instruction Set Computer

           An approach to processor design where the operations the hardware
           can perform are simplified but made as general purpose as
           possible. This can lead to lower power consumption, fewer
           transistors and in some cases, better performance and increased
           code density. Examples of RISC processors include the Alpha,
           SPARC(R), ARM(R) and PowerPC(R).

   Redundant Array of Inexpensive Disks

   Remote Procedure Call

   Request For Comments

           A set of documents defining Internet standards, protocols, and so
           forth. See www.rfc-editor.org.

           Also used as a general term when someone has a suggested change
           and wants feedback.

   Request To Send

           An RS232C signal requesting that the remote system commences
           transmission of data.

           See Also Clear To Send.

   Router Advertisement

  S

   SCI

           See System Control Interrupt.

   SCSI

           See Small Computer System Interface.

   SG

           See Signal Ground.

   SMB

           See Server Message Block.

   SMP

           See Symmetric MultiProcessor.

   SMTP

           See Simple Mail Transfer Protocol.

   SMTP AUTH

           See SMTP Authentication.

   SSH

           See Secure Shell.

   STR

           See Suspend To RAM.

   SVN

           See Subversion.

   SMTP Authentication

   Server Message Block

   Signal Ground

           An RS232 pin or wire that is the ground reference for the signal.

   Simple Mail Transfer Protocol

   Secure Shell

   Small Computer System Interface

   Subversion

           Subversion is a version control system currently used by the
           FreeBSD project.

   Suspend To RAM

   Symmetric MultiProcessor

   System Control Interrupt

  T

   TCP

           See Transmission Control Protocol.

   TCP/IP

           See Transmission Control Protocol/Internet Protocol.

   TD

           See Transmitted Data.

   TFTP

           See Trivial FTP.

   TGT

           See Ticket-Granting Ticket.

   TSC

           See Time Stamp Counter.

   Ticket-Granting Ticket

   Time Stamp Counter

           A profiling counter internal to modern Pentium(R) processors that
           counts core frequency clock ticks.

   Transmission Control Protocol

           A protocol that sits on top of (e.g.) the IP protocol and
           guarantees that packets are delivered in a reliable, ordered,
           fashion.

   Transmission Control Protocol/Internet Protocol

           The term for the combination of the TCP protocol running over the
           IP protocol. Much of the Internet runs over TCP/IP.

   Transmitted Data

           An RS232C pin or wire that data is transmitted on.

           See Also Received Data.

   Trivial FTP

  U

   UDP

           See User Datagram Protocol.

   UFS1

           See Unix File System Version 1.

   UFS2

           See Unix File System Version 2.

   UID

           See User ID.

   URL

           See Uniform Resource Locator.

   USB

           See Universal Serial Bus.

   Uniform Resource Locator

           A method of locating a resource, such as a document on the
           Internet and a means to identify that resource.

   Unix File System Version 1

           The original UNIX(R) file system, sometimes called the Berkeley
           Fast File System.

   Unix File System Version 2

           An extension to UFS1, introduced in FreeBSD 5-CURRENT. UFS2 adds
           64 bit block pointers (breaking the 1T barrier), support for
           extended file storage and other features.

   Universal Serial Bus

           A hardware standard used to connect a wide variety of computer
           peripherals to a universal interface.

   User ID

           A unique number assigned to each user of a computer, by which the
           resources and permissions assigned to that user can be identified.

   User Datagram Protocol

           A simple, unreliable datagram protocol which is used for
           exchanging data on a TCP/IP network. UDP does not provide error
           checking and correction like TCP.

  V

   VPN

           See Virtual Private Network.

   Virtual Private Network

           A method of using a public telecommunication such as the Internet,
           to provide remote access to a localized network, such as a
           corporate LAN.

                                     Index

  Symbols

   -CURRENT, Tracking a Development Branch

                compiling, Using FreeBSD-CURRENT

                using, Using FreeBSD-CURRENT

   -STABLE, Tracking a Development Branch

                compiling, Using FreeBSD-STABLE

                using, Using FreeBSD-STABLE

   .k5login, Configuring a Client to Use Kerberos

   .k5users, Configuring a Client to Use Kerberos

   .rhosts, File System Backups

   /boot/kernel.old, Building and Installing a Custom Kernel

   /etc, Designing the Partition Layout

   /etc/groups, Managing Groups

   /etc/login.conf, Configuring Login Classes

   /etc/mail/access, Sendmail Configuration Files

   /etc/mail/aliases, Sendmail Configuration Files

   /etc/mail/local-host-names, Sendmail Configuration Files

   /etc/mail/mailer.conf, Sendmail Configuration Files

   /etc/mail/mailertable, Sendmail Configuration Files

   /etc/mail/sendmail.cf, Sendmail Configuration Files

   /etc/mail/virtusertable, Sendmail Configuration Files

   /etc/remote, Using AT Commands

   /etc/ttys, Modem Configuration

   /usr, Designing the Partition Layout

   /usr/bin/login, Modem Configuration

   /usr/share/skel, adduser

   /var, Designing the Partition Layout

   386BSD, A Brief History of FreeBSD

   386BSD Patchkit, A Brief History of FreeBSD

   4.3BSD-Lite, A Brief History of FreeBSD

   4.4BSD-Lite, Welcome to FreeBSD!

   802.11 (see wireless networking)

  A

   AbiWord, AbiWord

   accounting

                disk space, Disk Quotas

   accounts

                adding, adduser

                changing password, passwd

                daemon, System Accounts

                groups, Managing Groups

                limiting, Configuring Login Classes

                modifying, Managing Accounts

                nobody, System Accounts

                operator, System Accounts

                removing, rmuser

                superuser (root), The Superuser Account

                system, System Accounts

                user, User Accounts

   ACL, Access Control Lists

   ACPI, Power and Resource Management, Common Problems

                ASL, BIOS Contains Buggy Bytecode, Overriding the Default AML

                debugging, Getting and Submitting Debugging Info

                problems, Common Problems, Getting and Submitting Debugging
                Info

   adduser, adduser, Utilities Which Change Login Classes

   AIX, Network Information System (NIS)

   anti-aliased fonts, Anti-Aliased Fonts

   Apache, Who Uses FreeBSD?, Apache HTTP Server

                configuration file, Configuring and Starting Apache

                modules, Apache Modules

                starting or stopping, Configuring and Starting Apache

   Apache OpenOffice , Apache OpenOffice

   APIC

                disabling, System Hangs

   APM, Power and Resource Management

   Apple, Who Uses FreeBSD?

   ASCII, Using Localization

   AT&T, A Brief History of FreeBSD

   AUDIT, Synopsis

   autofs, Automating Mounts with autofs(5)

   automounter subsystem, Automating Mounts with autofs(5)

   AutoPPP, Configuring Dial-in Services

  B

   backup software, Third-Party Backup Utilities

                cpio, Directory Backups

                dump / restore, File System Backups

                pax, Directory Backups

                tar, Directory Backups

   Basic Input/Output System (see BIOS)

   BGP, Configuring a Router with Static Routes

   binary compatibility

                Linux, Welcome to FreeBSD!, Synopsis

   BIND, Troubleshooting

   BIOS, FreeBSD Boot Process

   bits-per-second, Serial Terminology and Hardware

   Bluetooth, Bluetooth

   Bluetooth audio, Setting up Bluetooth Sound Devices

   Boot Loader, FreeBSD Boot Process

   Boot Manager, FreeBSD Boot Process, The Boot Manager

   boot-loader, Stage Three

   booting, Synopsis

   bootstrap, Synopsis

   Bourne shells, Shells

   bridge, Bridging

   browsers

                web, Browsers

   BSD Copyright, FreeBSD Project Goals

   BSD Router, Who Uses FreeBSD?

   bsdlabel, Emergency Recovery

  C

   Calligra, Calligra

   CARP, Common Address Redundancy Protocol (CARP)

   CD burner

                ATAPI, Creating and Using CD Media

                ATAPI/CAM driver, Supported Devices

   CD-ROMs

                burning, Burning a CD

                creating, Creating and Using CD Media

                creating bootable, Writing Data to an ISO File System

   CHAP, PAP and CHAP Authentication

   chpass, chpass

   Chromium, Chromium

   Cisco, Who Uses FreeBSD?

   Citrix, Who Uses FreeBSD?

   command line, Shells

   committers, The FreeBSD Development Model

   Common Address Redundancy Protocol, Common Address Redundancy Protocol
   (CARP)

   Compiler, What Can FreeBSD Do?

   Computer Systems Research Group (CSRG), Welcome to FreeBSD!

   Concurrent Versions System (see CVS)

   console, Virtual Consoles and Terminals, Single-User Mode

   contributors, The FreeBSD Development Model

   core team, The FreeBSD Development Model

   country codes, Using Localization

   cron

                configuration, Configuring cron(8)

   cryptography, SSL support

   cuau, Serial Port Configuration

   CVS, The FreeBSD Development Model

   CVS Repository, The FreeBSD Development Model

  D

   dangerously dedicated, Disk Organization

   DCE, Serial Terminology and Hardware

   device nodes, Troubleshooting Sound

   device.hints, Device Hints

   DGA, Determining Video Capabilities

   DHCP

                configuration files, Configuring a DHCP Client, Installing
                and Configuring a DHCP Server

                dhcpd.conf, Installing and Configuring a DHCP Server

                diskless operation, Configuring the DHCP Server

                installation, Installing and Configuring a DHCP Server

                server, Installing and Configuring a DHCP Server

   dial-in service, Dial-in Service

   dial-out service, Dial-out Service

   directories, Permissions

   directory hierarchy, Directory Structure

   Disk Labels, Labeling Disk Devices

   Disk Mirroring, RAID1 - Mirroring

   disk quotas, Resource Limits, Disk Quotas

                checking, Enabling Disk Quotas, Checking Quota Limits and
                Disk Usage

                limits, Setting Quota Limits

   diskless operation, Diskless Operation with PXE

   diskless workstation, Diskless Operation with PXE

   disks

                adding, Adding Disks

                detaching a memory disk, Attaching and Detaching Existing
                Images

                encrypting, Encrypting Disk Partitions

                memory, Attaching and Detaching Existing Images

                memory file system, Creating a File- or Memory-Backed Memory
                Disk

                resizing, Resizing and Growing Disks

   Django, Django

   DNS, Hostnames, Advanced Configuration, Mail Components, Mail for a
   Domain, Domain Name System (DNS)

   DNS Server, What Can FreeBSD Do?

   Documentation (see Updating and Upgrading)

   documentation package (see Updating and Upgrading)

   DSP, Troubleshooting Sound

   DTE, Serial Terminology and Hardware

   DTrace, Synopsis

   DTrace support (see DTrace)

   dual homed hosts, Configuring a Router with Static Routes

   dump, File System Backups

   DVD

                burning, Creating and Using DVD Media

                DVD+RW, Using a DVD+RW

                DVD-RAM, Using a DVD-RAM

                DVD-RW, Using a DVD-RW

                DVD-Video, Burning a DVD-Video

   Dynamic Host Configuration Protocol (see DHCP)

  E

   editors, Text Editors

                ee1, Text Editors

   ee, Text Editors

   electronic mail (see email)

   ELF, Advanced Topics

                branding, Advanced Topics

   emacs, Text Editors

   email, What Can FreeBSD Do?, Synopsis

                change mta, Changing the Mail Transfer Agent

                configuration, Basic Configuration

                receiving, Mail Components

                troubleshooting, Troubleshooting

   embedded, What Can FreeBSD Do?

   encodings, Using Localization

   environment variables, Shells

   ePDFView, ePDFView

   execution class loader, Advanced Topics

  F

   failover, Link Aggregation and Failover

   FEC, Link Aggregation and Failover

   fetchmail, Using fetchmail

   file permissions, Permissions

   file server

                UNIX clients, Network File System (NFS)

                Windows clients, File and Print Services for
                Microsoft(R) Windows(R) Clients (Samba)

   file systems

                ISO 9660, Creating and Using CD Media, Writing Data to an ISO
                File System

                Joliet, Writing Data to an ISO File System

                mounted with fstab, The fstab File

                mounting, Using mount(8)

                snapshots, File System Snapshots

                unmounting, Using umount(8)

   File Systems, Synopsis

   File Systems Support (see File Systems)

   Firefox, Firefox

   firewall, What Can FreeBSD Do?, Firewalls

                IPFILTER, IPFILTER (IPF)

                IPFW, IPFW

                PF, PF

                rulesets, Firewall Concepts

   fonts

                anti-aliased, Anti-Aliased Fonts

                spacing, Anti-Aliased Fonts

                TrueType, TrueType(R) Fonts

   Fonts

                LCD screen, Anti-Aliased Fonts

   Free Software Foundation, A Brief History of FreeBSD, GNU Info Files

   FreeBSD Project

                development model, The FreeBSD Development Model

                goals, FreeBSD Project Goals

                history, A Brief History of FreeBSD

   FreeBSD Security Advisories, FreeBSD Security Advisories

   freebsd-update (see updating-upgrading)

   FreeNAS, Who Uses FreeBSD?

   FreshPorts, Finding Software

   FTP

                anonymous, Configuration

   FTP servers, What Can FreeBSD Do?, File Transfer Protocol (FTP)

   Fudo Security, Who Uses FreeBSD?

  G

   gateway, Gateways and Routes

   Geeqie, Geeqie

   GEOM, Synopsis, RAID0 - Striping, RAID1 - Mirroring, RAID3 - Byte-level
   Striping with Dedicated Parity, Software RAID Devices, Labeling Disk
   Devices, UFS Journaling Through GEOM

   GEOM Disk Framework (see GEOM)

   getty, Modem Configuration

   GhostBSD, Who Uses FreeBSD?

   GNOME, What Can FreeBSD Do?, GNOME

   GNU General Public License (GPL), FreeBSD Project Goals

   GNU Lesser General Public License (LGPL), FreeBSD Project Goals

   GNU toolchain, Installing Linux(R) ELF Binaries

   GnuCash, GnuCash

   Gnumeric, Gnumeric

   gpart, Adding Disks, Resizing and Growing Disks

   grace period, Checking Quota Limits and Disk Usage

   Greenman, David, A Brief History of FreeBSD

   Grimes, Rod, A Brief History of FreeBSD

   groups, Managing Groups

   gv, gv

  H

   hard limit, Setting Quota Limits

   HAST

                high availability, Highly Available Storage (HAST)

   HCI, Finding Other Bluetooth Devices

   hostname, Hostnames

   hosts, /etc/hosts

   HP-UX, Network Information System (NIS)

   Hubbard, Jordan, A Brief History of FreeBSD

   hw.ata.wc, hw.ata.wc

  I

   I/O port, Troubleshooting Sound

   IEEE, Directory Backups

   image scanners, Image Scanners

   IMAP, Mail Components

   init8, FreeBSD Boot Process, Last Stage

   installation, Synopsis

                troubleshooting, Troubleshooting

   Intel i810 graphic chipset, Configuration with Intel(R) i810 Graphics
   Chipsets

   internationalization (see localization)

   Internet Systems Consortium (ISC), Dynamic Host Configuration Protocol
   (DHCP)

   interrupt storms, System Hangs

   IP aliases, Virtual Hosts

   IP masquerading (see NAT)

   IP subnet, Bridging

   IPFILTER

                enabling, Enabling IPF

                kernel options, Enabling IPF

                logging, IPF Logging

                rule syntax, IPF Rule Syntax

                statistics, Viewing IPF Statistics

   ipfstat, Viewing IPF Statistics

   IPFW

                enabling, Enabling IPFW

                kernel options, IPFW Kernel Options

                logging, Logging Firewall Messages

                rule processing order, IPFW Rule Syntax

                rule syntax, IPFW Rule Syntax

   ipfw, The IPFW Command

   ipmon, IPF Logging

   ipnat, Configuring NAT

   IPsec, VPN over IPsec

                AH, VPN over IPsec

                ESP, VPN over IPsec

   IRQ, Troubleshooting Sound

   Isilon, Who Uses FreeBSD?

   ISO 9660, Creating and Using CD Media

   iXsystems, Who Uses FreeBSD?

  J

   jails, Jails

   Jolitz, Bill, A Brief History of FreeBSD

   Journaling, UFS Journaling Through GEOM

   Juniper, Who Uses FreeBSD?

  K

   KDE, What Can FreeBSD Do?, KDE

                display manager, KDE

   Kerberos5

                configure clients, Configuring a Client to Use Kerberos

                enabling services, Configuring a Server to Use Kerberos

                external resources, Resources and Further Information

                Key Distribution Center, Setting up a Heimdal KDC

                limitations and shortcomings, Mitigating Kerberos Limitations

   kern.cam.scsi_delay, SCSI_DELAY (kern.cam.scsi_delay)

   kern.ipc.soacceptqueue, kern.ipc.soacceptqueue

   kern.maxfiles, kern.maxfiles

   kernel, FreeBSD Boot Process

                boot interaction, Stage Three

                bootflags, Last Stage

                building / installing, Building and Installing a Custom
                Kernel

                building a custom kernel, Synopsis

                configuration, Setting Up the Sound Card

                configuration file, The Configuration File

                NOTES, The Configuration File

   kernel options

                COMPAT_LINUX, Configuring Linux(R) Binary Compatibility

                IPFILTER, Enabling IPF

                IPFILTER_DEFAULT_BLOCK, Enabling IPF

                IPFILTER_LOG, Enabling IPF

                IPFIREWALL, IPFW Kernel Options

                IPFIREWALL_VERBOSE, IPFW Kernel Options

                IPFIREWALL_VERBOSE_LIMIT, IPFW Kernel Options

                IPSEC, VPN over IPsec

                IPSEC_DEBUG, VPN over IPsec

                MROUTING, Multicast Considerations

                SCSI DELAY, SCSI_DELAY (kern.cam.scsi_delay)

   keymap, Console Setup

   KLD (kernel loadable object), Using Windows(R) NDIS Drivers

   KMyMoney, KMyMoney

   Konqueror, Konqueror

  L

   L2CAP, Logical Link Control and Adaptation Protocol (L2CAP)

   LACP, Link Aggregation and Failover

   lagg, Link Aggregation and Failover

   language codes, Using Localization

   LCD screen, Anti-Aliased Fonts

   LCP, Configuring Dial-in Services

   LDAP, Lightweight Directory Access Protocol (LDAP), Security Settings

   LDAP Server, Configuring an LDAP Server

   LibreOffice, LibreOffice

   limiting users, Configuring Login Classes

                coredumpsize, Configuring Login Classes

                cputime, Configuring Login Classes

                filesize, Configuring Login Classes

                maxproc, Configuring Login Classes

                memorylocked, Configuring Login Classes

                memoryuse, Configuring Login Classes

                openfiles, Configuring Login Classes

                quotas, Resource Limits

                sbsize, Configuring Login Classes

                stacksize, Configuring Login Classes

   Linux, Network Information System (NIS)

                ELF binaries, Installing Linux(R) ELF Binaries

   Linux binary compatibility, Synopsis

   livefs CD, Emergency Recovery

   loadbalance, Link Aggregation and Failover

   loader, Stage Three

   loader configuration, Stage Three

   locale, Using Localization, Setting Locale for Login Shell

   localization, Synopsis

                German, Additional Language-Specific Resources

                Greek, Additional Language-Specific Resources

                Japanese, Additional Language-Specific Resources

                Korean, Additional Language-Specific Resources

                Russian, Russian Language (KOI8-R Encoding)

                Traditional Chinese, Additional Language-Specific Resources

   log files

                FTP, Configuration

   log management, Log Management and Rotation

   log rotation, Log Management and Rotation

   login class, Setting Locale for Login Shell, Utilities Which Change Login
   Classes

   ls1, Permissions

  M

   MAC, Synopsis

                File System Firewall Policy, The MAC BSD Extended Policy

   MAC Biba Integrity Policy, The MAC Biba Module

   MAC Configuration Testing, Testing the Configuration

   MAC Interface Silencing Policy, The MAC Interface Silencing Policy

   MAC LOMAC, The MAC Low-watermark Module

   MAC Multi-Level Security Policy, The MAC Multi-Level Security Module

   MAC Port Access Control List Policy, The MAC Port Access Control List
   Policy

   MAC Process Partition Policy, The MAC Partition Policy

   MAC See Other UIDs Policy, The MAC See Other UIDs Policy

   MAC Troubleshooting, Troubleshooting the MAC Framework

   MacOS, Generating a Single One-time Password

   mail host, Mail Components

   mail server daemons

                Exim, Mail Components

                Postfix, Mail Components

                qmail, Mail Components

                Sendmail, Mail Components

   Mail User Agents, Mail User Agents

   Mandatory Access Control (see MAC)

   manual pages, Manual Pages

   Master Boot Record (MBR), FreeBSD Boot Process, The Boot Manager

   McAfee, Who Uses FreeBSD?

   mencoder, MPlayer and MEncoder

   mfsBSD, Who Uses FreeBSD?

   mgetty, Configuring Dial-in Services

   Microsoft Windows, File and Print Services for Microsoft(R) Windows(R)
   Clients (Samba)

   Microsoft Windows

                device drivers, Using Windows(R) NDIS Drivers

   MidnightBSD, Who Uses FreeBSD?

   MIME, Setting Locale for Login Shell

   modem, Dial-in Service

   mod_perl

                Perl, mod_perl

   mod_php

                PHP, mod_php

   mountd, Network File System (NFS)

   moused, Console Setup

   MPlayer, MPlayer and MEncoder

   MS-DOS, Generating a Single One-time Password

   multi-user mode, Multi-User Mode

   multicast routing, Multicast Considerations

   MX record, Mail Components, Troubleshooting, Basic Configuration

  N

   Nagios in a MAC Jail, Nagios in a MAC Jail

   NAS4Free, Who Uses FreeBSD?

   NAT, What Can FreeBSD Do?, Configuring NAT

                and IPFW, In-kernel NAT

   NDIS, Using Windows(R) NDIS Drivers

   NDISulator, Using Windows(R) NDIS Drivers

   net.inet.ip.portrange.*, net.inet.ip.portrange.*

   Net/2, A Brief History of FreeBSD

   NetApp, Who Uses FreeBSD?

   NetBIOS, Advanced Configuration

   NetBSD, Network Information System (NIS)

   Netflix, Who Uses FreeBSD?

   netgroups, Using Netgroups

   network address translation (see NAT)

   network cards

                configuration, Setting Up Network Interface Cards,
                Configuring the Network Card

                driver, Locating the Correct Driver

                testing, Testing the Ethernet Card

                troubleshooting, Troubleshooting

   newsyslog, Log Management and Rotation

   newsyslog.conf, Log Management and Rotation

   NFS, Quotas over NFS, Network File System (NFS)

                configuration, Configuring the Server

                export examples, Configuring the Server

                installing multiple machines, Tracking for Multiple Machines

                mounting, Configuring the Client

                server, Network File System (NFS)

   nfsd, Network File System (NFS)

   NIS, Network Information System (NIS)

                client, Machine Types

                client configuration, Setting Up an NIS Client

                domain name, Choosing a NIS Domain Name

                domains, Network Information System (NIS)

                maps, Initializing the NIS Maps

                master server, Machine Types

                password formats, Password Formats

                server configuration, Configuring the NIS Master Server

                slave server, Machine Types, Setting up a NIS Slave Server

   NIS+, Security Settings

   NomadBSD, Who Uses FreeBSD?

   NOTES, The Configuration File

   Novell, A Brief History of FreeBSD

   NTP, NTP Configuration

                ntp.conf, The /etc/ntp.conf file

                ntpd, Clock Synchronization with NTP

                rc.conf, NTP entries in /etc/rc.conf

   null-modem cable, Serial Cables and Ports, In-Depth Serial Console
   Configuration

  O

   OBEX, OBEX Object Push (OPUSH)

   office suite

                Apache OpenOffice , Apache OpenOffice

                Calligra, Calligra

                LibreOffice, LibreOffice

   Okular, Okular

   one-time passwords, One-time Passwords

   OpenBSD, Network Information System (NIS)

   OpenSSH, OpenSSH

                client, Using the SSH Client Utilities

                enabling, Enabling the SSH Server

                secure copy, Using the SSH Client Utilities

                tunneling, SSH Tunneling

   OpenSSL

                certificate generation, Generating Certificates

   OPNsense, Who Uses FreeBSD?

   OSPF, Configuring a Router with Static Routes

  P

   packages, Synopsis

   PAP, PAP and CHAP Authentication

   partition layout, Designing the Partition Layout

   partitions, Disk Organization, Adding Disks, Resizing and Growing Disks

   passwd, passwd

   password, PAP and CHAP Authentication

   pax, Directory Backups

   PCI, Setting Up the Sound Card

   PDF

                viewing, Xpdf, gv, ePDFView, Okular

   permissions, Permissions

                symbolic, Symbolic Permissions

   pfSense, Who Uses FreeBSD?

   pgp keys, OpenPGP Keys

   pkg, Monitoring Third Party Security Issues

                search, Finding Software

   POP, Mail Components

   portmap, NIS Terms and Processes

   portmaster, Upgrading Ports Using Portmaster

   ports, Synopsis

                disk-space, Ports and Disk Space

                installing, Installing Ports

                removing, Removing Installed Ports

                upgrading, Upgrading Ports

                upgrading-tools, Tools to Upgrade and Manage Ports

   Ports Collection, Configuring Linux(R) Binary Compatibility

   portupgrade, Upgrading Ports Using Portupgrade

   POSIX, Directory Backups, Setting Locale for Login Shell

   PostScript

                viewing, gv

   PPP, Synopsis

                configuration, Final System Configuration

                Microsoft extensions, Advanced Configuration

                NAT, Using PPP Network Address Translation Capability

                over ATM, Using PPP over ATM (PPPoA)

                over Ethernet, Synopsis, Using PPP over Ethernet (PPPoE)

                troubleshooting, Troubleshooting PPP Connections

                with static IP addresses, Basic Configuration

   PPPoA, Using PPP over ATM (PPPoA)

   print server

                Windows clients, File and Print Services for
                Microsoft(R) Windows(R) Clients (Samba)

   printers, Russian Language (KOI8-R Encoding)

   Process Accounting, Process Accounting

   procmail, Using procmail

   pw, pw, Utilities Which Change Login Classes

   Python, Django

  Q

   Quest KACE, Who Uses FreeBSD?

   quotas, Resource Limits

  R

   RAID1, RAID1 - Mirroring

   RAID3, RAID3 - Byte-level Striping with Dedicated Parity

   rc files, Multi-User Mode

                rc.conf, Managing System-Specific Configuration

                rc.serial, Serial Port Configuration, Modem Configuration

   resolv.conf, /etc/resolv.conf

   resolver, Domain Name System (DNS)

   Resource limits, Resource Limits

   restore, File System Backups

   reverse DNS, Domain Name System (DNS)

   RIP, Configuring a Router with Static Routes

   rmuser, rmuser

   root file system, Mounting and Unmounting File Systems

   root zone, Domain Name System (DNS)

   roundrobin, Link Aggregation and Failover

   routed, Final System Configuration

   router, What Can FreeBSD Do?, Configuring a Router with Static Routes

   routing, Gateways and Routes

   rpcbind, Network File System (NFS), NIS Terms and Processes

   Ruby on Rails, Ruby on Rails

  S

   Samba server, File and Print Services for Microsoft(R) Windows(R) Clients
   (Samba)

   Sandvine, Who Uses FreeBSD?

   scp1, Using the SSH Client Utilities

   screenmap, Console Setup

   SDL, Determining Video Capabilities

   SDP, Service Discovery Protocol (SDP)

   security, Security

                firewalls, Firewalls

                one-time passwords, One-time Passwords

                OpenSSH, OpenSSH

                OpenSSL, OpenSSL

   Security

                Sudo, Shared Administration with Sudo

   Security Event Auditing (see MAC)

   sendmail, Final System Configuration

   Sendmail, Sendmail Configuration Files

   serial communications, Synopsis

   serial console, Setting Up the Serial Console

   services, Starting Services

   shared libraries, Installing Additional Libraries Manually

   shells, Shells

   shutdown8, Shutdown Sequence

   single-user mode, Stage Three, Single-User Mode

   skeleton directory, adduser

   slices, Disk Organization

   SMTP, Final System Configuration, Basic Configuration

   soft limit, Setting Quota Limits

   Soft Updates, Soft Updates

                details, More Details About Soft Updates

   Software RAID Devices

                Hardware-assisted RAID, Software RAID Devices

   Solaris, Advanced Topics, Network Information System (NIS)

   Sony, Who Uses FreeBSD?

   Sophos, Who Uses FreeBSD?

   sound cards, Setting Up the Sound Card

   SourceForge, Finding Software

   Spectra Logic, Who Uses FreeBSD?

   spreadsheet

                Gnumeric, Gnumeric

                KMyMoney, KMyMoney

   SQL database, Security Settings

   SSL, SSL support

   static IP address, Configuring PPP

   Stormshield, Who Uses FreeBSD?

   Striping, RAID0 - Striping

   subnet, Gateways and Routes

   Subversion, The FreeBSD Development Model, Using FreeBSD-STABLE, Using
   Subversion

   Subversion Repository, The FreeBSD Development Model

                Mirror Sites, Subversion Mirror Sites

   SVN (see Subversion)

   swap

                encrypting, Encrypting Swap

   swap partition, Designing the Partition Layout

   swap sizing, Designing the Partition Layout

   symbolic links, Installing Additional Libraries Manually

   sysctl, Tuning with sysctl(8), sysctl.conf

   sysctl.conf, sysctl.conf

   syslog, Configuring System Logging, Configuration

   syslog.conf, Configuring Local Logging

   syslogd8, Configuring System Logging

   system configuration, Synopsis

   system logging, Configuring System Logging

   system optimization, Synopsis

  T

   tape media, Using Data Tapes for Backups

   tar, Directory Backups

   TCP Bandwidth Delay Product Limiting

                net.inet.tcp.inflight.enable, TCP Bandwidth Delay Product

   TCP Wrapper, TCP Wrapper, NIS Security

   TCP/IP networking, Welcome to FreeBSD!

   terminals, Virtual Consoles and Terminals, Terminals

   tether, USB Tethering

   text editors, Text Editors

   The GIMP, The GIMP

   The Weather Channel, Who Uses FreeBSD?

   traceroute8, Troubleshooting

   Traditional Chinese

                BIG-5 encoding, Login Classes Method

   TrueOS, Who Uses FreeBSD?

   TrueType Fonts, TrueType(R) Fonts

   ttyu, Serial Port Configuration

   tunefs8, Soft Updates

   tuning

                kernel limits, Tuning Kernel Limits

                with sysctl, Tuning with sysctl(8)

   TV cards, TV Cards

  U

   U.C. Berkeley, A Brief History of FreeBSD

   UDP, Configuring a DHCP Client

   UNIX, Permissions

   Updating and Upgrading, FreeBSD Update, Updating the Documentation Set,
   Updating Documentation from Ports

   USB

                disks, USB Storage Devices

   users

                large sites running FreeBSD, Who Uses FreeBSD?

  V

   Verisign, Who Uses FreeBSD?

   vfs.hirunningspace, vfs.hirunningspace

   vfs.vmiodirenable, vfs.vmiodirenable

   vfs.write_behind, vfs.write_behind

   vi, Text Editors

   video packages, Ports and Packages Dealing with Video

   video ports, Ports and Packages Dealing with Video

   vipw, Utilities Which Change Login Classes

   virtual consoles, Virtual Consoles and Terminals

   virtual hosts, Virtual Hosts

   Virtual LANs, VLANs

   virtual private network (see VPN)

   VLANs, VLANs

   vm.swap_idle_enabled, vm.swap_idle_enabled

   Voxer, Who Uses FreeBSD?

   VPN, VPN over IPsec

  W

   Walnut Creek CDROM, A Brief History of FreeBSD

   web servers

                dynamic, Dynamic Websites

                secure, SSL support

                setting up, Apache HTTP Server

   widescreen flatpanel configuration, Adding a Widescreen Flatpanel to the
   Mix

   Williams, Nate, A Brief History of FreeBSD

   Windows, Generating a Single One-time Password

   Windows drivers, Using Windows(R) NDIS Drivers

   wireless networking, Wireless Networking

  X

   X Display Manager, The X Display Manager

   X Input Method (XIM), Xorg Setup

   X Window System, What Can FreeBSD Do?

   XML, Anti-Aliased Fonts

   Xorg, Xorg Configuration

   Xorg tuning, Troubleshooting

   xorg.conf, Troubleshooting

   Xpdf, Xpdf

   XVideo, Determining Video Capabilities

  Y

   yellow pages (see NIS)

  Z

   zones

                examples, Domain Name System (DNS)

   ZRouter, Who Uses FreeBSD?

                                    Colophon

   This book is the combined work of hundreds of contributors to "The FreeBSD
   Documentation Project". The text is authored in XML according to the
   DocBook DTD and is formatted from XML into many different presentation
   formats using XSLT. The printed version of this document would not be
   possible without Donald Knuth's TeX typesetting language, Leslie Lamport's
   LaTeX, or Sebastian Rahtz's JadeTeX macro package.
