Linux Administration, Networking, and Security

815 Pages·2009·36.6 MB·English

10
Linux
Administration,
Networking,
and
Security

To Aliena and Jesse
Fedora 10 Linux Administration, Networking, and Security
Richard Petersen

Surfing Turtle Press
Alameda, CA

Please send inquires to: [email protected]

Library of Congress Control Number: 2009901225

ISBN 0-9820998-3-5
ISBN-13 978-0-9820998-3-4
Copyright Richard Petersen, 2009
All rights reserved
Copyright 2009 by Richard Petersen. All rights reserved. Printed in the United States of
America.
Except as permitted under the Copyright Act of 1976, no part of this publication may be
reproduced or distributed in any form or by any means, or stored in a database or retrieval system,
without the prior written permission of the publisher, with the exception that the program listings
may be entered, stored, and executed in a computer system, but they may not be reproduced for
publication.,
Information has been obtained by Surfing Turtle Press from sources believed to be
reliable. However, because of the possibility of human or mechanical error by our sources, Surfing
Turtle Press, the author Richard Petersen, or others, Surfing Turtle Press does not guarantee the
accuracy, adequacy, or completeness of any information and is not responsible for any errors or
omissions or the results obtained from use of such information.
Limit of Liability and Disclaimer of Warranty: The publisher and the author make no
representation or warranties with respect to the accuracy or completeness of the contents of this
work and specifically disclaim all warranties, including without limitation warranties of fitness for
a particular purpose. The information and code in this book is provided on "as is" basis. No
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Trademark Acknowledgements
UNIX is a trademark of The Open Group
Microsoft and MS-DOS are registered trademarks of Microsoft Corporation
IBM and PC are registered trademarks of the International Business Machines Corporation
Red Hat and Fedora are trademarks of Red Hat, Inc.
and are trademarks of Red Hat, Inc
See www.fedoraproject.org/wiki/Logo/ for more information
is the Solar background image for Fedora 10
is a trademark of Surfing Turtle Press

Preface
This book is designed as an administration and security reference. Administration tools are
covered as well as the underlying configuration files and system implementations. The emphasis is
on what administrators will need to know to perform key administration and security tasks. Topics
covered include user management, time server settings, start up configuration, software
management, kernel configuration, SELinux, and file system management. Server tools are covered
as well as the underlying configuration files and system implementations. Topics covered include
network connections, IP network administration, software management, Upstart service
management, runlevels, and the Network Time Protocol. Key servers are examined, including Web,
FTP, CUPS printing, NFS, and Samba Windows shares. Network support servers and applications
covered include the Squid proxy server, the Domain Name System (BIND) server, DHCP, and
IPtables firewalls.
The book is organized into six parts: system administration, security, and file system and
device management, network services, shared resources, and network support.
Part 1 focuses on administrative tasks such as managing users, managing software with
PackageKit, customizing the kernel, and setting up virtual systems.
Part 2 keys in on security tasks beginning with authorizations using PolicyKit. GPG
encryption support with seahorse as well as the structure of public/private key encryption is
covered. File and directory permissions, along with access controls are examined. SELinux tools
and the format and command structure of SELinux configurations are discussed. SSH encryptions
and Kerberos authentication are also examined. The security section ends with a detailed
examination of IPtables firewalls and the system-config-firewall tool.
Part 3 deals with file systems and devices. File systems formats are discussed in detail
along with mount and encryption operations. LVM and Linux RAID are covered. For devices, both
HAL and udev are examined in detail. Backup applications for your file systems are then discussed.
Part 4 examines Internet servers as well as how all services are managed by Upstart using
runlevels. Configuration and implementation of the Postfix mail server, the vsftpd FTP server, the
Apache Web server, as well as news and database servers are covered in detail.
Part 5 deals with servers that provide shared resources on a local network or the Internet.
Services examined include the Cups printing server, NFS Linux network file server, and Samba
Windows file and printing server, and the GFS distributed file system.
Part 6 covers servers that provide network support: configuring network connections, the
Squid proxy server, the Bind Domain Name System (DNS) server, DHCP servers, and IPv6
network addressing and monitoring.

Overview

Preface.......................................................................................................5
Overview....................................................................................................7
Contents ..................................................................................................11

Part 1: System Administration
1. Fedora 10 Introduction.......................................................................45
2. Basic System Administration.............................................................59
3. System Startup and Services.............................................................89
4. Installing and Updating Software....................................................121
5. System Information...........................................................................153
6. Managing Users................................................................................167
7. Kernel Administration.......................................................................191
8. Virtualization......................................................................................211
8 Overview

Part 2: Security
9. Authorization .....................................................................................225
10. Encryption........................................................................................235
11. File and Directory Access...............................................................253
12. Security Enhanced Linux................................................................271
13. SSH, Kerberos, and IPsec...............................................................301
14. Firewalls...........................................................................................319

Part 3: Devices and File Systems
15. File System management................................................................353
16. LVM and RAID..................................................................................385
17. Devices.............................................................................................409
18. Backup..............................................................................................439
19. Shell Configuration..........................................................................455

Part 4: Network Services
20. Mail Servers .....................................................................................477
21. FTP....................................................................................................501
Overview 9
22. Web Servers....................................................................................517
23. News and Database Services.........................................................543

Part 5: Shared Resources
24. Print Services..................................................................................551
25. Network File Systems and Network Information Service: NFS and
NIS..........................................................................................................579
26. Samba..............................................................................................599
27. Distributed Network File Systems.................................................627

Part 6: Network Support
28. Network Connections.....................................................................637
29. Proxy Servers: Squid......................................................................663
30. Domain Name System ....................................................................671
31. Network Auto-configuration with IPv6, DHCPv6, and DHCP.......717
32. Administering TCP/IP Networks....................................................733

Appendix A: Getting Fedora ................................................................769
Appendix B: Fedora Live DVD/CD.......................................................771
10 Overview
Table Listing ..........................................................................................783
Figure Listing.........................................................................................789
Index.......................................................................................................797

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