linux firewall

Red Hat Linux Firewalls
$50.00
What I was looking for in this was a book explaining IPTABLES. What I got was much more. The book starts with overall theory and firewalls in practice, basics off the major network protocols, TCP, UDP, and then moves into the how-to's and breaks down the iptables commands. Script examples are great, already put some of his suggestions into practice.
Would recommend to anyone building a Linux firewall.

Linux Firewalls: Attack Detection and Response with iptables, psad, and fwsnort
$49.95
This was a great book! Helped me understand networking, linux, and iptables better. Michael Rash has written some great software, and this is also a definitive guide on it.

Linux Networking Cookbook
$44.99
I expected a book on setting up and administration of networks in a Linux environment. This book does provide it BUT it explains each aspect in the context of using a specific piece of software. This is ONLY a setup/administration guide for those who need a what to install nice tools to administer their systems.
Not a manual instruction book.

Configuring IPCop Firewalls: Closing Borders with Open Source: How to setup, configure and manage your Linux firewall, web proxy, DHCP, DNS, time server, ... VPN with this powerful Open Source solution
$39.99
I frankly expected more from this book. It is short (220 pages), and consists largely of screenshots of IPCop configuration screens interspersed with descriptions of what each page means. If you have no idea how a firewall works, this book will help you get started. If you have any significant networking experience and are looking for a book to assist you with configuring and debugging a network firewall, then it won't be of much help.