iptables-tutorial.html: This is a copy of Oskar Andreasson's iptables 
  tutorial.
ipsysctl-tutorial.html: This is a copy of Oskar Andreasson's ipsysctl 
  tutorial.
networking_101.txt: This document is still a work in progress, but it should
  be reasonable complete as an introduction to basic networking concepts.
packet_flow.png: This details the flow of packets through the various tables
  and chains.
tables_traverse.jpg: This is similar to the packet_flow.png image but
  simplified a bit -- this image was taken from Oskar Andreasson's iptables
  tutorial.

rc.firewall.alamo: This is my firewall script on my gateway box at home.
rc.firewall.desktop.generic: This is a generic firewall script that should
  work on a standalone box connected directly to the internet (some minor
  modification might be necessary).
rc.firewall.gateway.generic: This is a generic firewall script for a gateway
  box (serving as a firewall/gateway for a small LAN).
sshattacks: This details some example rules (and explains them) for blocking
  brute force ssh attacks.