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 Linuxฎ 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
Section 1 Getting Started
Section 2 Tools and Internals
Section 3 Diagnostics