References

• Linux Firewalling HOWTO - old, but a good place to start
  http://metalab.unc.edu/LDP/HOWTO/Firewall-HOWTO.html
• Freefire Project
  http://sites.inka.de/sites/lina/freefire-l/index.en.html
• Robert Ziegler's Linux Firewall and Security Site
  http://rlz.ne.mediaone.net/linux/
• Ipfwadm Paper (2.0)
  http://www.xos.nl/linux/ipfwadm/paper/
• Another Ipfwadm Paper (2.0)
  http://raven.genome.washington.edu/security/linux-firewalling.txt
• Linux IP Firewalling Chains (2.1/2.2)
  http://www.rustcorp.com/linux/ipchains/
• TIS Firewall Toolkit
  http://www.fwtk.org/
• Juniper Firewall Toolkit and smptd
  http://www.obtuse.com/
• SINUS Firewall Page
  http://www.ifi.unizh.ch/ikm/SINUS/firewall/