This Reference Index contains a list of links to information sources on network and computer security. Netsurfer Digest also has a Computer And Network Security Resource Index.
Web site contains links to different network architectures.
It provides an overview of firewall components and the general reasoning behind firewall usage. This work is a contribution of the National Institute of Standards and Technology. All you need to know about firewalls but didn't know who to ask. A list of frequently asked questions of Firewalls. The Firewalls mailing list is for discussions of Internet firewall security systems and related issues.