Building Internet Firewalls Written by D. Brent Chatman and others.  Published by O'Reilly This book spends a great amount of time and detail mapping out successful designs for various firewall implementations. The authors detail the pro’s and con’s for every suggested design, but does not go into great detail about specific configurations with specific proxy servers for the obvious reason that the technology changes so fast and new products are entering the market at a rate that the authors cannot keep up with in a paper based media.  The best part of this book is Chapter 9, which gives two sample firewall configurations and a description of each rule in the rule base. It starts with an architectural discussion and then leads into service configuration. It finishes each sample with an analysis of the thought process that went into the development of the security policy.  The final chapter outlines a pretty good process of maintaining your firewall as well as some tips on monitoring and what course of action to take in the event of an attack. The appendices that follow contain tons of useful online resources for security lists, response teams, security tools, proxy servers and a good discussion of TCP/IP.  Overall this is a great analysis of what it takes to build, maintain and monitor both a proxy based and packet filtering firewall. The emphasis is on Unix based systems with no focus on any particular firewall product.
		Linux Firewalls Written by Robert L. Ziegler.  Published by New Riders. Great book! Got broadband at home? Want a free firewall by using your old pc that is collecting dust for ages? Here is your answer. This book has lots of details of how to build a packet filter linux firewall based on ipchains. The author shows the examples of his scripts and this is how your scripts should look like. It starts from the very basic to a complex setup. Note: this book only focus on threats from the outside, not from the inside!!!!!!!