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Your Official Red Hat® Linux® Guide to Networking and System Administration ® ®
R eviewed by the experts at Red Hat, this in-depth guide delivers all ®
the know-how you need to set up and manage a state-of-the-art Linux
network. ®
Red Hat Linux experts Terry Collings and Kurt Wall start with the P R E S S™
basics—network planning and Red Hat installation and configuration. Te r r y C o l l i n g s & K u r t W a l l
and System Administration
Red Hat Linux Networking
They then show you in detail how to set up network and Internet services,
from establishing a network file system to configuring mail services. Eight
chapters give you the lowdown on customizing the kernel, automating
tasks with scripting, performing backups, and more—the nuts-and-bolts
maintenance information you need to keep your system running smoothly.
And last but not least, the authors provide nearly 100 pages of proven
CD-ROM INCLUDES
strategies and tips for maintaining system security.
Complete with utilities and code on CD-ROM, this official Red Hat Linux networking and
®
Linux guide is the one resource you need for a secure, high-performance administration tools,
Linux network.
including Ethereal,
logcheck, NET-SNMP,
Proven Red Hat Linux Networking and Administration Solutions
N m a p, Po r t s e n t r y,
■ Plan your network, install Red Hat Linux, and get a handle on the file
Tripwire and SAINT
system and configuration files
trial version
■ Configure TCP/IP networking, the Network File System, and the Net-
®
work Information System
Code, scripts, and ex-
■ Set up print services and connections to Windows and Macintosh clients
amples from the book
■ Monitor performance, administer users and groups, back up and restore
the file system, and install or upgrade software packages Plus a searchable
■ Design a security plan, implement local security, set up firewalls and
e-version of the book
proxy servers, and combat system intrusions
■ Troubleshoot file system, networking, printing, and e-mail problems
Reader Level
TERRY COLLINGS is the Instructional Technologist at Muhlenberg College in Intermediate to
Advanced
Pennsylvania, where he is responsible for developing smart classroom
technologies. He is also the coauthor of the Linux Bible. Shelving Category
OOLS IN
Networking Y T C
K URT W ALL has worked with Linux and Unix for nine years and is the IT H E CD-R L
T
UR
author of several other books, including Red Hat Linux 7.2 Weekend $59.99 USA O
UD
ON
SEC
$89.99 Canada
M
ED
Crash Course and Linux Programming by Example.
£44.99 UK incl.VAT
Reviewed by the Experts at Red Hat SECURITY TOOLS
ISBN 0-7645-3632-X
www.redhat.com
INCLUDED ON CD-ROM Linux Solutions from the Experts at Red Hat
www.hungryminds.com
55999
Cover design by Collings
Michael J. Freeland & Wall ®
® P R E S S™
9 780764 536328 7 8 5 5 5 5 09538 0 Cover photo © Hulton Getty
a3632-X FM.F 2/21/02 8:33 AM Page i
Red Hat® Linux® Networking
and System Administration
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Red Hat® Linux®
Networking and
System
Administration
Terry Collings and Kurt Wall
M&T Books
An imprint of Hungry Minds, Inc.
Best-Selling Books ● Digital Downloads ● e-Books ● Answer Networks
e-Newsletters ● Branded Web Sites ● e-Learning
New York, NY ● Cleveland, OH ● Indianapolis, IN
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Red Hat® Linux® Networking and System Administration
Published by
Hungry Minds, Inc.
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Copyright © 2002 Hungry Minds, Inc. All rights reserved. No part of this book, including interior design, cover design,
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is a trademark of Hungry Minds, Inc. is a trademark of Hungry Minds, Inc.
a3632-X FM.F 2/21/02 8:33 AM Page v
About the Authors
Terry Collings has been working in the computer field since 1981 and has
experience in all types of operating systems and their associated hardware. He has
industry certifications in Novell, TCP/IP, MS Windows, and Unix. Terry’s full-time
job is at Muhlenberg College in Allentown, PA, where he is the school’s
Instructional Technologist. His main function in this position is assisting faculty in
the use of computer technology to augment their classroom presentations. He is
also the system administrator for the school’s online course content management
software. Terry also teaches a wide range of computer and technology-related
courses in the evenings at Allentown Business School. Terry has been a technical
editor for several Hungry Minds, Inc., books and is the co-author of the Linux Bible.
He can be reached at [email protected].
Kurt Wall first touched a computer in 1980 when he learned FORTRAN on an
IBM mainframe of forgotten vintage; things have only gotten better since then.
These days, Kurt is a full-time Linux and Unix author, editor, consultant, and
programmer. He has written five books about Linux and Unix programming and
system administration, is working on his sixth, and is the technical editor for over
a dozen other Linux- and Unix-related titles. Currently, Kurt works from his home
in Indianapolis. He can be reached via e-mail at [email protected].
a3632-X FM.F 2/21/02 8:33 AM Page vi
Credits
CONTRIBUTING WRITERS QUALITY CONTROL TECHNICIANS
Viktorie Navratilova Laura Albert
Dennis Powell Luisa Perez
Brandon Wiley Carl Pierce
Marianne Santy
ACQUISITIONS EDITOR
Terri Varveris SENIOR PERMISSIONS EDITOR
Carmen Krikorian
PROJECT EDITOR
Martin V. Minner MEDIA DEVELOPMENT SPECIALIST
Greg Stephens
TECHNICAL EDITORS
Joel Lee MEDIA DEVELOPMENT COORDINATOR
Matt Hayden Marisa Pearman
Sandra Moore
COVER DESIGN
COPY EDITOR Michael Freeland
Marti Paul
COVER PHOTO
RED HAT PRESS LIAISON Hulton Getty
Lorien Golaski, Red Hat
Communications Manager PROOFREADING AND INDEXING
TECHBOOKS Production Services
PROJECT COORDINATOR
Dale White
GRAPHICS AND PRODUCTION
SPECIALISTS
Beth Brooks
Sean Decker
Melanie DesJardins
Jeremey Unger
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This book is dedicated to the victims and heroes of September 11, 2001.
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Preface
Red Hat Linux is the most popular distribution of Linux currently in use. Red Hat
Linux has shown itself to be a robust, reliable operating system that can run on a
variety of hardware, from personal computers to large mainframes. Linux in general,
and Red Hat Linux in particular, is a very powerful operating system that can be used
at the enterprise level as a full-fledged server, as well as at the workstation level for
typical user applications. For those of us dissatisfied with the reliability of other com-
mercially available operating systems, Red Hat Linux is a pleasant alternative.
How This Book Is Organized
This book is divided into five parts. Each part covers a specific area of functionality
in a typical Red Hat Linux system.
Part I — Red Hat Linux System and Network
Administration Defined
This part describes the duties of a system administrator. Chapter 1 explains some of
the more common tasks, such as installing servers and application software,
managing user accounts, and backing up and restoring files. Many more topics are
covered in this chapter. Chapter 2 details the steps involved in planning and build-
ing a network and planning for security and disaster recovery. Chapter 3 takes you
through the steps required to install Red Hat Linux on a local system as well as on
a remote system. Chapter 4 gives an explanation of the Red Hat Linux file system
and storage devices. Chapter 5, the last chapter in Part I, lists the system and
network configuration files and their uses.
Part II — Red Hat Linux Network Services
This part of the book is where you learn about the networking services available in
Red Hat Linux. Chapter 6 gives an explanation of the TCP/IP protocol suite and
how to configure it on your system. Chapter 7 tells how to configure the Network
File System (NFS) for sharing files with other Linux or Unix computers on your
network. Chapter 8 provides a description of the Network Information System (NIS)
as well as configuration instructions. If you have computers running Microsoft
operating systems, Chapter 9 is where you find instructions for connecting your
Red Hat Linux network to the Windows network. The final chapter in this part,
Chapter 10, tells you how to connect your Red Hat Linux network to computers
running the Apple operating system.
ix
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x Preface
Part III — Red Hat Linux Internet Services
Internet services are somewhat different from network services used on an internal
network. Chapter 11 begins this part by explaining Internet services, and includes a
discussion of the xinetd and TCP wrappers configuration files.A fundamental part of
using the Internet is the ability to enter a domain name and have it converted into
an IP number that is the actual address of a computer. The name-to-number conver-
sion is done by the Domain Name System (DNS), which is covered in Chapter 12.
Chapter 13 describes the File Transfer Protocol (FTP) and gives installation and con-
figuration instructions. Sending and receiving e-mail has become so common that
it’s hard to remember the time before we had it. Chapter 14 explains mail services
and its configuration. Last, but not least, you find an explanation of setting up a
Web server. Chapter 15 covers Apache, one of the most popular Web servers in use.
Part IV — Red Hat Linux System Maintenance
The goal of this part of the book is to provide a fundamental understanding of the
tasks required to maintain your system and ensure that it runs optimally. Chapter 16
explains the Red Hat Network, a service available from Red Hat that you can use to
keep your system current. You can register your systems with Red Hat and then
receive notifications of updated or new software that can be installed. Chapter 17
discusses upgrading and customizing the kernel for your specific needs. Chapter 18
tells you how to use the command line to perform all of your system administrative
tasks. If you want to use scripts to automate some of your work, Chapter 19 is where
you find out how to do it. Chapter 20 deals with monitoring the performance of your
system. Creating users and groups is a basic part of system maintenance, and
Chapter 21 describes this process. Chapter 22 details the steps necessary to back up
your file system and use the backups to restore your system. The final chapter in this
part, Chapter 23, gives instructions on installing and upgrading software packages.
Part V — Security and Problem Solving
A critical area of concern for system administrators is maintaining a secure system.
Most of the chapters in this part deal with security, beginning with Chapter 24,
which covers security basics. Chapter 25 addresses local, or host-based, security. In
Chapter 26 you find an explanation of firewalls and Internet security and the risks
you may encounter from outside connections. Chapter 27 looks at ways to monitor
a Red Hat Linux system for attempted, potential, and actual security compromises
using the tools available in a standard Red Hat Linux installation. The last chapter
in this part, Chapter 28, lists problems you may encounter during normal operation
of your system and the steps to take to solve the problems discussed.
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Preface xi
How to Use This Book
Our intention for this book is to cover the Red Hat Linux operating system in
enough detail to provide the answers that you need. The book is divided into the
parts previously discussed to make it easy for you to go to the specific part for the
topic you need to learn about. You can use the book as a reference for whatever
you need to know about a particular topic.
Using this book’s icons
Watch for the following margin icons to help you get the most out of this book:
Tips provide special information or advice.
Caution icons warn you of a potential problem or error.
This icon directs you to related information in another section or chapter.
A Note highlights an area of interest or special concern related to the topic.
This icon points you toward related material on the book’s CD-ROM.
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xii Preface
Conventions
This book uses the following conventions for explanations of how to do things on
your computer:
◆ Italic type introduces new technical terms. It also indicates replaceable
arguments that you should substitute with actual values — the context
makes clear the distinction between new terms and replaceable arguments.
◆ Bold type shows a command you type in.
◆ Monospaced text distinguishes commands, options, and arguments from
surrounding explanatory content.
◆ Keys to press in combination are shown like this example: Ctrl+Alt+Delete
means to press all three keys at the same time.
◆ The term click means to press the left mouse button once. Double-click
means to press the left button twice in quick succession. Right click means
to press the right mouse button once. Drag means to hold down the left
mouse button and move the mouse while holding down the button.
a3632-X FM.F 2/21/02 8:33 AM Page xiii
Terry Collings’s
Acknowledgments
Until I started writing books, I never realized how many people are involved with
producing a book like this and how much work they do. The first person I want to
thank is my coauthor, Kurt Wall. Kurt is the reason I became involved with working
on Linux books when I was asked to technical edit a Linux book several years ago.
Since then, Kurt and I have collaborated on other projects, most recently this book.
I also want to acknowledge the hard work of Viktorie Navratilova, Dennis
Powell, and Brandon Wiley who stepped in and wrote several chapters for me when
I was out with a medical problem. Their help was a significant contribution to the
completion of this book.
A special thank-you goes out to Terri Varveris, my acquisitions editor at Hungry
Minds. Terri is a wonderful person to work with and is one of the nicest people I
have ever known. She is also responsible for choosing our project editor, Marty
Minner. Marty is very organized and he makes sure we do our jobs, but in a nice
way that makes him a pleasure to work with. Finally, thanks to our copy editor,
technical editors, and production staff at Hungry Minds for their efforts in ensuring
that our work is technically accurate as well as grammatically correct and properly
presented.
Finally, I would like to thank my wife Nancy for all her support and encourage-
ment. She is my true inspiration.
xiii
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Kurt Wall’s
Acknowledgments
Like Terry, I appreciate the work of Viktorie, Dennis, and Brandon in helping Terry
and me complete this book when Terry became ill. Thanks to Terri Varveris for
giving me the chance to write about Linux, something I truly enjoy doing — Terri,
let’s do this again. Here’s a vigorous nod to Marty Minner, who deftly managed the
day-to-day details of converting raw manuscript into a finished book — every
author should have such a capable, patient, and witty project editor. Kudos as well
to the rest of the team at Hungry Minds who labored to make this book a reality.
I would be remiss if I failed to thank Terry Collings for inviting me to participate
in this book — he may yet decide that I didn’t do him any favors by getting him
involved in writing books. I look forward to another opportunity to work with him.
I would like to extend my deepest thanks to and appreciation of the mission and
members of Mount Tabor Lutheran Church in Salt Lake City — their service and
example kept me going in dark, trying times.
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Contents at a Glance
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . xiii
Part I Red Hat Linux System and Network
Administration Defined
Chapter 1 Duties of the System Administrator . . . . . . . . . . . . . 3
Chapter 2 Planning the Network . . . . . . . . . . . . . . . . . . . . . . 13
Chapter 3 Installing Red Hat Linux . . . . . . . . . . . . . . . . . . . . 27
Chapter 4 Red Hat Linux File System . . . . . . . . . . . . . . . . . . 71
Chapter 5 Red Hat System Configuration Files . . . . . . . . . . . 93
Part II Red Hat Linux Network Services
Chapter 6 TCP/IP Networking . . . . . . . . . . . . . . . . . . . . . . . 123
Chapter 7 The Network File System . . . . . . . . . . . . . . . . . . . 153
Chapter 8 The Network Information System . . . . . . . . . . . . 185
Chapter 9 Connecting to Microsoft Networks . . . . . . . . . . . . 209
Chapter 10 Connecting to Apple Networks . . . . . . . . . . . . . . 235
Part III Red Hat Linux Internet Services
Chapter 11 What are Internet Services? . . . . . . . . . . . . . . . . 253
Chapter 12 The Domain Name System . . . . . . . . . . . . . . . . . . 271
Chapter 13 Configuring FTP Services . . . . . . . . . . . . . . . . . . . 301
Chapter 14 Configuring Mail Services . . . . . . . . . . . . . . . . . . 335
Chapter 15 Configuring a Web Server . . . . . . . . . . . . . . . . . . 365
Part IV Red Hat Linux System Maintenance
Chapter 16 Using the Red Hat Network . . . . . . . . . . . . . . . . . 403
Chapter 17 Upgrading and Customizing the Kernel . . . . . . . . 419
Chapter 18 Configuring the System on the Command Line . . . 463
Chapter 19 Using Scripts to Automate Tasks . . . . . . . . . . . . . 503
Chapter 20 Performance Monitoring . . . . . . . . . . . . . . . . . . . 551
Chapter 21 Administering Users and Groups . . . . . . . . . . . . . 575
Chapter 22 Backing up and Restoring the File System . . . . . . 615
Chapter 23 Installing and Upgrading Software Packages . . . . 643
xv
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Part V Security and Problem Solving
Chapter 24 Security Basics . . . . . . . . . . . . . . . . . . . . . . . . . . 685
Chapter 25 Implementing Local Security . . . . . . . . . . . . . . . . 705
Chapter 26 Firewalls and Internet Security . . . . . . . . . . . . . . 731
Chapter 27 Detecting Intrusions . . . . . . . . . . . . . . . . . . . . . . 749
Chapter 28 Troubleshooting and Problem Solving . . . . . . . . . 767
Appendix: What’s on the CD-ROM? . . . . . . . . . . . 787
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 791
End-User License Agreement . . . . . . . . . . . . . . . . 847
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Contents
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii
Part I Red Hat Linux System and Network
Administration Defined
Chapter 1 Duties of the System Administrator . . . . . . . . . . . . . . . 3
The Linux System Administrator . . . . . . . . . . . . . . . . . . . . . . 3
Installing and Configuring Servers . . . . . . . . . . . . . . . . . . . . 5
Installing and Configuring Application Software . . . . . . . . . 6
Creating and Maintaining User Accounts . . . . . . . . . . . . . . . 7
Backing Up and Restoring Files . . . . . . . . . . . . . . . . . . . . . . . 7
Monitoring and Tuning Performance . . . . . . . . . . . . . . . . . . . 9
Configuring a Secure System . . . . . . . . . . . . . . . . . . . . . . . . 10
Using Tools to Monitor Security . . . . . . . . . . . . . . . . . . . . . 11
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Chapter 2 Planning the Network . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Deciding What Kind of Network You Need . . . . . . . . . . . . . 13
Understanding topologies . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Client/server or peer-to-peer? . . . . . . . . . . . . . . . . . . . . . . . . . 16
What’s in the mix? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Determining system requirements . . . . . . . . . . . . . . . . . . . . . . 19
Planning and Implementing Security . . . . . . . . . . . . . . . . . 20
Addressing external and internal threats . . . . . . . . . . . . . . . . . 20
Formulating a security policy . . . . . . . . . . . . . . . . . . . . . . . . . 21
Planning for Recovery from Disasters . . . . . . . . . . . . . . . . . 22
Write It Down — Good Records Can Save Your Job . . . . . . . 24
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Chapter 3 Installing Red Hat Linux . . . . . . . . . . . . . . . . . . . . . . . . 27
Exploring Your PC’s Components . . . . . . . . . . . . . . . . . . . . 27
Processor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Video card and monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Hard drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Floppy disk drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Keyboard and mouse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
SCSI controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
CD-ROM drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
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xviii Contents
Sound card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Network card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Checking for Supported Hardware . . . . . . . . . . . . . . . . . . . . 31
Creating the Red Hat Boot Disk . . . . . . . . . . . . . . . . . . . . . . 31
Starting the Red Hat Linux Installation . . . . . . . . . . . . . . . . 32
Partitioning the Hard Disk for Red Hat Linux . . . . . . . . . . . 36
Naming disks and devices . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Mounting a file system on a device . . . . . . . . . . . . . . . . . . . . . 37
Understanding the swap partition . . . . . . . . . . . . . . . . . . . . . . 38
Preparing disk partitions for Red Hat Linux . . . . . . . . . . . . . . . 39
Configuring Red Hat Linux Installation . . . . . . . . . . . . . . . . 43
Installing the Boot Loader . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Configuring the network . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Setting the time zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Setting the root password and add user accounts . . . . . . . . . . . 48
Configuring password authentication . . . . . . . . . . . . . . . . . . . 49
Selecting the Package Groups to Install . . . . . . . . . . . . . . . . 51
Completing the Installation . . . . . . . . . . . . . . . . . . . . . . . . . 53
Using KickStart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
KickStart Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Auth — Authentication Options . . . . . . . . . . . . . . . . . . . . . . . 57
bootloader . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
clearpart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
device --opts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
driverdisk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
firewall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
install . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Installation methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
interactive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
keyboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
language . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
lilo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
lilocheck . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
mouse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
partition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
raid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
reboot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
rootpw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
skipx . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
timezone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
upgrade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
xconfig . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
zerombr — Partition table initialization . . . . . . . . . . . . . . . . . . 67
%packages — Package Selection . . . . . . . . . . . . . . . . . . . . . . . 67
a3632-X FM.F 2/21/02 8:33 AM Page xix
Contents xix
%pre — Pre-Installation Configuration Section . . . . . . . . . . . . . 69
%post — Post-Installation Configuration Section . . . . . . . . . . . . 69
Starting a KickStart Installation . . . . . . . . . . . . . . . . . . . . . 69
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Chapter 4 Red Hat Linux File System . . . . . . . . . . . . . . . . . . . . . . 71
Understanding the Red Hat Linux File System Structure . . . 71
The / directory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Using File System Commands . . . . . . . . . . . . . . . . . . . . . . . 74
ls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
cp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
rm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
mv . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
chown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
chgrp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
chmod . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
chattr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
ln . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
symlinks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
stat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
lsof . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
mknod . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
macutil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Working With Linux—Supported File Systems . . . . . . . . . . . 79
Standard disk file systems . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Nonstandard Linux file systems . . . . . . . . . . . . . . . . . . . . . . . 82
Memory file systems and virtual file systems . . . . . . . . . . . . . . 83
Linux Disk Management . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Partitioning an x86 machine . . . . . . . . . . . . . . . . . . . . . . . . . 89
Mounting other OS partitions/slices . . . . . . . . . . . . . . . . . . . . 89
Metadevices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Chapter 5 Red Hat System Configuration Files . . . . . . . . . . . . . . 93
Examining the System Configuration Files . . . . . . . . . . . . . 94
Systemwide shell configuration scripts . . . . . . . . . . . . . . . . . . 94
System environmental settings . . . . . . . . . . . . . . . . . . . . . . . . 97
System configuration files in the /etc/sysconfig directory . . . . . 105
Examining the Network Configuration Files . . . . . . . . . . . 105
Files to change when setting up a system
or moving the system . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Starting up network services from xinetd . . . . . . . . . . . . . . . . 111
Starting up network services from the rc scripts . . . . . . . . . . . 112
Other important network configuration files
in the /etc/sysconfig directory . . . . . . . . . . . . . . . . . . . . . . 113
Network configuration files in /etc/sysconfig/network-scripts . . 113
R eviewed by the experts at Red Hat, this in-depth guide delivers all ®
the know-how you need to set up and manage a state-of-the-art Linux
network. ®
Red Hat Linux experts Terry Collings and Kurt Wall start with the P R E S S™
basics—network planning and Red Hat installation and configuration. Te r r y C o l l i n g s & K u r t W a l l
and System Administration
Red Hat Linux Networking
They then show you in detail how to set up network and Internet services,
from establishing a network file system to configuring mail services. Eight
chapters give you the lowdown on customizing the kernel, automating
tasks with scripting, performing backups, and more—the nuts-and-bolts
maintenance information you need to keep your system running smoothly.
And last but not least, the authors provide nearly 100 pages of proven
CD-ROM INCLUDES
strategies and tips for maintaining system security.
Complete with utilities and code on CD-ROM, this official Red Hat Linux networking and
®
Linux guide is the one resource you need for a secure, high-performance administration tools,
Linux network.
including Ethereal,
logcheck, NET-SNMP,
Proven Red Hat Linux Networking and Administration Solutions
N m a p, Po r t s e n t r y,
■ Plan your network, install Red Hat Linux, and get a handle on the file
Tripwire and SAINT
system and configuration files
trial version
■ Configure TCP/IP networking, the Network File System, and the Net-
®
work Information System
Code, scripts, and ex-
■ Set up print services and connections to Windows and Macintosh clients
amples from the book
■ Monitor performance, administer users and groups, back up and restore
the file system, and install or upgrade software packages Plus a searchable
■ Design a security plan, implement local security, set up firewalls and
e-version of the book
proxy servers, and combat system intrusions
■ Troubleshoot file system, networking, printing, and e-mail problems
Reader Level
TERRY COLLINGS is the Instructional Technologist at Muhlenberg College in Intermediate to
Advanced
Pennsylvania, where he is responsible for developing smart classroom
technologies. He is also the coauthor of the Linux Bible. Shelving Category
OOLS IN
Networking Y T C
K URT W ALL has worked with Linux and Unix for nine years and is the IT H E CD-R L
T
UR
author of several other books, including Red Hat Linux 7.2 Weekend $59.99 USA O
UD
ON
SEC
$89.99 Canada
M
ED
Crash Course and Linux Programming by Example.
£44.99 UK incl.VAT
Reviewed by the Experts at Red Hat SECURITY TOOLS
ISBN 0-7645-3632-X
www.redhat.com
INCLUDED ON CD-ROM Linux Solutions from the Experts at Red Hat
www.hungryminds.com
55999
Cover design by Collings
Michael J. Freeland & Wall ®
® P R E S S™
9 780764 536328 7 8 5 5 5 5 09538 0 Cover photo © Hulton Getty
a3632-X FM.F 2/21/02 8:33 AM Page i
Red Hat® Linux® Networking
and System Administration
a3632-X FM.F 2/21/02 8:33 AM Page ii
a3632-X FM.F 2/21/02 8:33 AM Page iii
Red Hat® Linux®
Networking and
System
Administration
Terry Collings and Kurt Wall
M&T Books
An imprint of Hungry Minds, Inc.
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a3632-X FM.F 2/21/02 8:33 AM Page iv
Red Hat® Linux® Networking and System Administration
Published by
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is a trademark of Hungry Minds, Inc. is a trademark of Hungry Minds, Inc.
a3632-X FM.F 2/21/02 8:33 AM Page v
About the Authors
Terry Collings has been working in the computer field since 1981 and has
experience in all types of operating systems and their associated hardware. He has
industry certifications in Novell, TCP/IP, MS Windows, and Unix. Terry’s full-time
job is at Muhlenberg College in Allentown, PA, where he is the school’s
Instructional Technologist. His main function in this position is assisting faculty in
the use of computer technology to augment their classroom presentations. He is
also the system administrator for the school’s online course content management
software. Terry also teaches a wide range of computer and technology-related
courses in the evenings at Allentown Business School. Terry has been a technical
editor for several Hungry Minds, Inc., books and is the co-author of the Linux Bible.
He can be reached at [email protected].
Kurt Wall first touched a computer in 1980 when he learned FORTRAN on an
IBM mainframe of forgotten vintage; things have only gotten better since then.
These days, Kurt is a full-time Linux and Unix author, editor, consultant, and
programmer. He has written five books about Linux and Unix programming and
system administration, is working on his sixth, and is the technical editor for over
a dozen other Linux- and Unix-related titles. Currently, Kurt works from his home
in Indianapolis. He can be reached via e-mail at [email protected].
a3632-X FM.F 2/21/02 8:33 AM Page vi
Credits
CONTRIBUTING WRITERS QUALITY CONTROL TECHNICIANS
Viktorie Navratilova Laura Albert
Dennis Powell Luisa Perez
Brandon Wiley Carl Pierce
Marianne Santy
ACQUISITIONS EDITOR
Terri Varveris SENIOR PERMISSIONS EDITOR
Carmen Krikorian
PROJECT EDITOR
Martin V. Minner MEDIA DEVELOPMENT SPECIALIST
Greg Stephens
TECHNICAL EDITORS
Joel Lee MEDIA DEVELOPMENT COORDINATOR
Matt Hayden Marisa Pearman
Sandra Moore
COVER DESIGN
COPY EDITOR Michael Freeland
Marti Paul
COVER PHOTO
RED HAT PRESS LIAISON Hulton Getty
Lorien Golaski, Red Hat
Communications Manager PROOFREADING AND INDEXING
TECHBOOKS Production Services
PROJECT COORDINATOR
Dale White
GRAPHICS AND PRODUCTION
SPECIALISTS
Beth Brooks
Sean Decker
Melanie DesJardins
Jeremey Unger
a3632-X FM.F 2/21/02 8:33 AM Page vii
This book is dedicated to the victims and heroes of September 11, 2001.
a3632-X FM.F 2/21/02 8:33 AM Page viii
a3632-X FM.F 2/21/02 8:33 AM Page ix
Preface
Red Hat Linux is the most popular distribution of Linux currently in use. Red Hat
Linux has shown itself to be a robust, reliable operating system that can run on a
variety of hardware, from personal computers to large mainframes. Linux in general,
and Red Hat Linux in particular, is a very powerful operating system that can be used
at the enterprise level as a full-fledged server, as well as at the workstation level for
typical user applications. For those of us dissatisfied with the reliability of other com-
mercially available operating systems, Red Hat Linux is a pleasant alternative.
How This Book Is Organized
This book is divided into five parts. Each part covers a specific area of functionality
in a typical Red Hat Linux system.
Part I — Red Hat Linux System and Network
Administration Defined
This part describes the duties of a system administrator. Chapter 1 explains some of
the more common tasks, such as installing servers and application software,
managing user accounts, and backing up and restoring files. Many more topics are
covered in this chapter. Chapter 2 details the steps involved in planning and build-
ing a network and planning for security and disaster recovery. Chapter 3 takes you
through the steps required to install Red Hat Linux on a local system as well as on
a remote system. Chapter 4 gives an explanation of the Red Hat Linux file system
and storage devices. Chapter 5, the last chapter in Part I, lists the system and
network configuration files and their uses.
Part II — Red Hat Linux Network Services
This part of the book is where you learn about the networking services available in
Red Hat Linux. Chapter 6 gives an explanation of the TCP/IP protocol suite and
how to configure it on your system. Chapter 7 tells how to configure the Network
File System (NFS) for sharing files with other Linux or Unix computers on your
network. Chapter 8 provides a description of the Network Information System (NIS)
as well as configuration instructions. If you have computers running Microsoft
operating systems, Chapter 9 is where you find instructions for connecting your
Red Hat Linux network to the Windows network. The final chapter in this part,
Chapter 10, tells you how to connect your Red Hat Linux network to computers
running the Apple operating system.
ix
a3632-X FM.F 2/21/02 8:33 AM Page x
x Preface
Part III — Red Hat Linux Internet Services
Internet services are somewhat different from network services used on an internal
network. Chapter 11 begins this part by explaining Internet services, and includes a
discussion of the xinetd and TCP wrappers configuration files.A fundamental part of
using the Internet is the ability to enter a domain name and have it converted into
an IP number that is the actual address of a computer. The name-to-number conver-
sion is done by the Domain Name System (DNS), which is covered in Chapter 12.
Chapter 13 describes the File Transfer Protocol (FTP) and gives installation and con-
figuration instructions. Sending and receiving e-mail has become so common that
it’s hard to remember the time before we had it. Chapter 14 explains mail services
and its configuration. Last, but not least, you find an explanation of setting up a
Web server. Chapter 15 covers Apache, one of the most popular Web servers in use.
Part IV — Red Hat Linux System Maintenance
The goal of this part of the book is to provide a fundamental understanding of the
tasks required to maintain your system and ensure that it runs optimally. Chapter 16
explains the Red Hat Network, a service available from Red Hat that you can use to
keep your system current. You can register your systems with Red Hat and then
receive notifications of updated or new software that can be installed. Chapter 17
discusses upgrading and customizing the kernel for your specific needs. Chapter 18
tells you how to use the command line to perform all of your system administrative
tasks. If you want to use scripts to automate some of your work, Chapter 19 is where
you find out how to do it. Chapter 20 deals with monitoring the performance of your
system. Creating users and groups is a basic part of system maintenance, and
Chapter 21 describes this process. Chapter 22 details the steps necessary to back up
your file system and use the backups to restore your system. The final chapter in this
part, Chapter 23, gives instructions on installing and upgrading software packages.
Part V — Security and Problem Solving
A critical area of concern for system administrators is maintaining a secure system.
Most of the chapters in this part deal with security, beginning with Chapter 24,
which covers security basics. Chapter 25 addresses local, or host-based, security. In
Chapter 26 you find an explanation of firewalls and Internet security and the risks
you may encounter from outside connections. Chapter 27 looks at ways to monitor
a Red Hat Linux system for attempted, potential, and actual security compromises
using the tools available in a standard Red Hat Linux installation. The last chapter
in this part, Chapter 28, lists problems you may encounter during normal operation
of your system and the steps to take to solve the problems discussed.
a3632-X FM.F 2/21/02 8:33 AM Page xi
Preface xi
How to Use This Book
Our intention for this book is to cover the Red Hat Linux operating system in
enough detail to provide the answers that you need. The book is divided into the
parts previously discussed to make it easy for you to go to the specific part for the
topic you need to learn about. You can use the book as a reference for whatever
you need to know about a particular topic.
Using this book’s icons
Watch for the following margin icons to help you get the most out of this book:
Tips provide special information or advice.
Caution icons warn you of a potential problem or error.
This icon directs you to related information in another section or chapter.
A Note highlights an area of interest or special concern related to the topic.
This icon points you toward related material on the book’s CD-ROM.
a3632-X FM.F 2/21/02 8:33 AM Page xii
xii Preface
Conventions
This book uses the following conventions for explanations of how to do things on
your computer:
◆ Italic type introduces new technical terms. It also indicates replaceable
arguments that you should substitute with actual values — the context
makes clear the distinction between new terms and replaceable arguments.
◆ Bold type shows a command you type in.
◆ Monospaced text distinguishes commands, options, and arguments from
surrounding explanatory content.
◆ Keys to press in combination are shown like this example: Ctrl+Alt+Delete
means to press all three keys at the same time.
◆ The term click means to press the left mouse button once. Double-click
means to press the left button twice in quick succession. Right click means
to press the right mouse button once. Drag means to hold down the left
mouse button and move the mouse while holding down the button.
a3632-X FM.F 2/21/02 8:33 AM Page xiii
Terry Collings’s
Acknowledgments
Until I started writing books, I never realized how many people are involved with
producing a book like this and how much work they do. The first person I want to
thank is my coauthor, Kurt Wall. Kurt is the reason I became involved with working
on Linux books when I was asked to technical edit a Linux book several years ago.
Since then, Kurt and I have collaborated on other projects, most recently this book.
I also want to acknowledge the hard work of Viktorie Navratilova, Dennis
Powell, and Brandon Wiley who stepped in and wrote several chapters for me when
I was out with a medical problem. Their help was a significant contribution to the
completion of this book.
A special thank-you goes out to Terri Varveris, my acquisitions editor at Hungry
Minds. Terri is a wonderful person to work with and is one of the nicest people I
have ever known. She is also responsible for choosing our project editor, Marty
Minner. Marty is very organized and he makes sure we do our jobs, but in a nice
way that makes him a pleasure to work with. Finally, thanks to our copy editor,
technical editors, and production staff at Hungry Minds for their efforts in ensuring
that our work is technically accurate as well as grammatically correct and properly
presented.
Finally, I would like to thank my wife Nancy for all her support and encourage-
ment. She is my true inspiration.
xiii
a3632-X FM.F 2/21/02 8:33 AM Page xiv
Kurt Wall’s
Acknowledgments
Like Terry, I appreciate the work of Viktorie, Dennis, and Brandon in helping Terry
and me complete this book when Terry became ill. Thanks to Terri Varveris for
giving me the chance to write about Linux, something I truly enjoy doing — Terri,
let’s do this again. Here’s a vigorous nod to Marty Minner, who deftly managed the
day-to-day details of converting raw manuscript into a finished book — every
author should have such a capable, patient, and witty project editor. Kudos as well
to the rest of the team at Hungry Minds who labored to make this book a reality.
I would be remiss if I failed to thank Terry Collings for inviting me to participate
in this book — he may yet decide that I didn’t do him any favors by getting him
involved in writing books. I look forward to another opportunity to work with him.
I would like to extend my deepest thanks to and appreciation of the mission and
members of Mount Tabor Lutheran Church in Salt Lake City — their service and
example kept me going in dark, trying times.
a3632-X FM.F 2/21/02 8:33 AM Page xv
Contents at a Glance
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . xiii
Part I Red Hat Linux System and Network
Administration Defined
Chapter 1 Duties of the System Administrator . . . . . . . . . . . . . 3
Chapter 2 Planning the Network . . . . . . . . . . . . . . . . . . . . . . 13
Chapter 3 Installing Red Hat Linux . . . . . . . . . . . . . . . . . . . . 27
Chapter 4 Red Hat Linux File System . . . . . . . . . . . . . . . . . . 71
Chapter 5 Red Hat System Configuration Files . . . . . . . . . . . 93
Part II Red Hat Linux Network Services
Chapter 6 TCP/IP Networking . . . . . . . . . . . . . . . . . . . . . . . 123
Chapter 7 The Network File System . . . . . . . . . . . . . . . . . . . 153
Chapter 8 The Network Information System . . . . . . . . . . . . 185
Chapter 9 Connecting to Microsoft Networks . . . . . . . . . . . . 209
Chapter 10 Connecting to Apple Networks . . . . . . . . . . . . . . 235
Part III Red Hat Linux Internet Services
Chapter 11 What are Internet Services? . . . . . . . . . . . . . . . . 253
Chapter 12 The Domain Name System . . . . . . . . . . . . . . . . . . 271
Chapter 13 Configuring FTP Services . . . . . . . . . . . . . . . . . . . 301
Chapter 14 Configuring Mail Services . . . . . . . . . . . . . . . . . . 335
Chapter 15 Configuring a Web Server . . . . . . . . . . . . . . . . . . 365
Part IV Red Hat Linux System Maintenance
Chapter 16 Using the Red Hat Network . . . . . . . . . . . . . . . . . 403
Chapter 17 Upgrading and Customizing the Kernel . . . . . . . . 419
Chapter 18 Configuring the System on the Command Line . . . 463
Chapter 19 Using Scripts to Automate Tasks . . . . . . . . . . . . . 503
Chapter 20 Performance Monitoring . . . . . . . . . . . . . . . . . . . 551
Chapter 21 Administering Users and Groups . . . . . . . . . . . . . 575
Chapter 22 Backing up and Restoring the File System . . . . . . 615
Chapter 23 Installing and Upgrading Software Packages . . . . 643
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Part V Security and Problem Solving
Chapter 24 Security Basics . . . . . . . . . . . . . . . . . . . . . . . . . . 685
Chapter 25 Implementing Local Security . . . . . . . . . . . . . . . . 705
Chapter 26 Firewalls and Internet Security . . . . . . . . . . . . . . 731
Chapter 27 Detecting Intrusions . . . . . . . . . . . . . . . . . . . . . . 749
Chapter 28 Troubleshooting and Problem Solving . . . . . . . . . 767
Appendix: What’s on the CD-ROM? . . . . . . . . . . . 787
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 791
End-User License Agreement . . . . . . . . . . . . . . . . 847
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Contents
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii
Part I Red Hat Linux System and Network
Administration Defined
Chapter 1 Duties of the System Administrator . . . . . . . . . . . . . . . 3
The Linux System Administrator . . . . . . . . . . . . . . . . . . . . . . 3
Installing and Configuring Servers . . . . . . . . . . . . . . . . . . . . 5
Installing and Configuring Application Software . . . . . . . . . 6
Creating and Maintaining User Accounts . . . . . . . . . . . . . . . 7
Backing Up and Restoring Files . . . . . . . . . . . . . . . . . . . . . . . 7
Monitoring and Tuning Performance . . . . . . . . . . . . . . . . . . . 9
Configuring a Secure System . . . . . . . . . . . . . . . . . . . . . . . . 10
Using Tools to Monitor Security . . . . . . . . . . . . . . . . . . . . . 11
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Chapter 2 Planning the Network . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Deciding What Kind of Network You Need . . . . . . . . . . . . . 13
Understanding topologies . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Client/server or peer-to-peer? . . . . . . . . . . . . . . . . . . . . . . . . . 16
What’s in the mix? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Determining system requirements . . . . . . . . . . . . . . . . . . . . . . 19
Planning and Implementing Security . . . . . . . . . . . . . . . . . 20
Addressing external and internal threats . . . . . . . . . . . . . . . . . 20
Formulating a security policy . . . . . . . . . . . . . . . . . . . . . . . . . 21
Planning for Recovery from Disasters . . . . . . . . . . . . . . . . . 22
Write It Down — Good Records Can Save Your Job . . . . . . . 24
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Chapter 3 Installing Red Hat Linux . . . . . . . . . . . . . . . . . . . . . . . . 27
Exploring Your PC’s Components . . . . . . . . . . . . . . . . . . . . 27
Processor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Video card and monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Hard drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Floppy disk drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Keyboard and mouse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
SCSI controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
CD-ROM drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
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Sound card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Network card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Checking for Supported Hardware . . . . . . . . . . . . . . . . . . . . 31
Creating the Red Hat Boot Disk . . . . . . . . . . . . . . . . . . . . . . 31
Starting the Red Hat Linux Installation . . . . . . . . . . . . . . . . 32
Partitioning the Hard Disk for Red Hat Linux . . . . . . . . . . . 36
Naming disks and devices . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Mounting a file system on a device . . . . . . . . . . . . . . . . . . . . . 37
Understanding the swap partition . . . . . . . . . . . . . . . . . . . . . . 38
Preparing disk partitions for Red Hat Linux . . . . . . . . . . . . . . . 39
Configuring Red Hat Linux Installation . . . . . . . . . . . . . . . . 43
Installing the Boot Loader . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Configuring the network . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Setting the time zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Setting the root password and add user accounts . . . . . . . . . . . 48
Configuring password authentication . . . . . . . . . . . . . . . . . . . 49
Selecting the Package Groups to Install . . . . . . . . . . . . . . . . 51
Completing the Installation . . . . . . . . . . . . . . . . . . . . . . . . . 53
Using KickStart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
KickStart Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Auth — Authentication Options . . . . . . . . . . . . . . . . . . . . . . . 57
bootloader . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
clearpart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
device --opts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
driverdisk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
firewall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
install . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Installation methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
interactive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
keyboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
language . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
lilo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
lilocheck . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
mouse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
partition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
raid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
reboot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
rootpw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
skipx . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
timezone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
upgrade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
xconfig . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
zerombr — Partition table initialization . . . . . . . . . . . . . . . . . . 67
%packages — Package Selection . . . . . . . . . . . . . . . . . . . . . . . 67
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%pre — Pre-Installation Configuration Section . . . . . . . . . . . . . 69
%post — Post-Installation Configuration Section . . . . . . . . . . . . 69
Starting a KickStart Installation . . . . . . . . . . . . . . . . . . . . . 69
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Chapter 4 Red Hat Linux File System . . . . . . . . . . . . . . . . . . . . . . 71
Understanding the Red Hat Linux File System Structure . . . 71
The / directory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Using File System Commands . . . . . . . . . . . . . . . . . . . . . . . 74
ls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
cp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
rm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
mv . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
chown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
chgrp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
chmod . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
chattr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
ln . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
symlinks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
stat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
lsof . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
mknod . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
macutil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Working With Linux—Supported File Systems . . . . . . . . . . . 79
Standard disk file systems . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Nonstandard Linux file systems . . . . . . . . . . . . . . . . . . . . . . . 82
Memory file systems and virtual file systems . . . . . . . . . . . . . . 83
Linux Disk Management . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Partitioning an x86 machine . . . . . . . . . . . . . . . . . . . . . . . . . 89
Mounting other OS partitions/slices . . . . . . . . . . . . . . . . . . . . 89
Metadevices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Chapter 5 Red Hat System Configuration Files . . . . . . . . . . . . . . 93
Examining the System Configuration Files . . . . . . . . . . . . . 94
Systemwide shell configuration scripts . . . . . . . . . . . . . . . . . . 94
System environmental settings . . . . . . . . . . . . . . . . . . . . . . . . 97
System configuration files in the /etc/sysconfig directory . . . . . 105
Examining the Network Configuration Files . . . . . . . . . . . 105
Files to change when setting up a system
or moving the system . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Starting up network services from xinetd . . . . . . . . . . . . . . . . 111
Starting up network services from the rc scripts . . . . . . . . . . . 112
Other important network configuration files
in the /etc/sysconfig directory . . . . . . . . . . . . . . . . . . . . . . 113
Network configuration files in /etc/sysconfig/network-scripts . . 113