Linux Packet Filtering and iptables by Oskar Andreasson
Publisher: Linuxtopia 2005
This document was simply written to give everyone a good and simple primer at how to get started with iptables, but at the same time it was created to be as complete as possible. This document requires some previous knowledge about Linux/Unix, shell scripting, as well as how to compile your own kernel, and some simple knowledge about the kernel internals.
Computers & Internet Operating Systems Linux Administration