Firewalls and Network Address Translation

• Network (In)Security Through IP Packet Filtering, 1992.
• Linux 2.4 kernel Firewalling Matures: netfilter
• UW Network Security Credo
• IP over HTTP:
  • HTTP tunnel
  • HTTP-TUNNEL
  • TCP Tunnel
• IP Network Address Translator (NAT) Terminology and Considerations, more NAT information
• SOCKS description and implementation
• The "rainbow" books (Orange Book, etc.)
• IP Network Address Translation, Diplomarbeit by Michael Hasenstein, 1997
• Linux NAT implementations
• CheckPoint Firewall-1: a typical software firewall