Troubleshooting Linux Firewalls

Description:

Covers Red Hat and SUSE

When something goes wrong with your Linux firewall, you need to fix it—right now. You don't have time for endless newsgroup searches, confusing man pages, emails to the developers... it's an emergency! One book brings together all the step-by-step solutions and proven problem-solving techniques you'll need when the time comes: Troubleshooting Linux® Firewalls.

Authors Michael Shinn and Scott Shinn are among the world's leading firewall experts; they've even been hired to protect computer security at the White House. In this book, they cover every area where Linux firewalls can go wrong: rules and filtering problems, Layer 2/3/4 issues, trouble with individual services, DNS/DHCP failures, even misconfigured VPNs. They also present an easy, start-to-finish troubleshooting methodology that'll help you identify even the newest or most obscure firewall problem fast—and solve it!

Inside, you will find in-depth information on the following areas:

• What you must know about iptables and netfilter to troubleshoot and avoid problems

• Using loggers, sniffers, and other tools to diagnose even the most obscure firewall problems

• Making sure your firewall rules work the way they're supposed to

• Resolving problems with Network Address Translation and IP Forwarding

• Troubleshooting SMTP, Apache, Squid, NFS, FTP, instant messaging, and other Web-based services

• Finding and fixing common problems with IPsec VPN configuration

• Making your firewalls more failure-resistant: recommendations from the experts

If you depend on a Linux firewall, what will you do if it goes down? With Troubleshooting Linux® Firewalls, you can be confident that the solutions are right at hand—so you can sleep at night!

 

SECTION I: GETTING STARTED.

1: Introduction.

2: Getting Started.

3: Local firewall Security.

4: Troubleshooting Methodology.

SECTION II: TOOLS AND INTERNALS.

5: The OSI Model: Start from the Beginning.

6: Netfilter and iptables Overview.

7: Using iptables.

8: A tour of our Collective Toolbox.

9: Diagnostics.

SECTION III: DIAGNOSTICS.

10: Testing your firewall rules (for security!).

11: Layer 2/In-Line Filtering.

12: NAT (Network Address Translation) and IP Forwarding.

13: General IP (Layer 3/Layer 4).

14: SMTP (e-mail).

15: Web Services (Apache and Squid).

16: File Services    (NFS and FTP).

17: Instant Messaging.

18: DNS/DHCP.

19: Virtual Private Networks.