- The ULTIMATELY Secure Firewall đ
- Open High Availability Fireall Designs
- yet another Firewall list
- How to Build a Successful Security Infrastructure
- PhoneBoy’s FireWall-1 FAQ
- Cisco – Improving Security on Cisco Routers
- Cisco – Increasing Security On IP Networks
- Building Your Firewall Rulebase
- Creating a VPN between a Cisco router and a Checkpoint Firewall using manual IPSEC
- Firewall Admins Guide to P*rn Guide for firewall admins who have to deal with this issue.
- FireWall-1 FAQ Page
- Placing Backdoors trough Firewalls
- Bastille Linux
- sf Firewall Software — a TCP/IP packet filter for Linux
- ipfilter FAQ
- netfilter/iptables
- The Internet Firewall FAQ
- Internet standards you should know, if you set up an external screening or border router: