Cisco IOS Firewall Configuration Example: Here is an example of the Cisco IOS running as a firewall. It's not the most efficient firewall available because each session consumes 128kb of RAM. In busy networks this would bring down the router quickly, but it works great for small home or SOHO networks.
Cisco PIX Firewall Configuration Example: This is an example of a Cisco PIX (version 6.3.5) firewall configuration. It includes a simple DMZ configuration for a secure webserver in the DMZ as well.