How to implement a Firewall

[codingfreak]

HI

I am planning to really make myself dirty with coding a Firewall on Linux machine.

My real aim is to have some practical implementation of a Firewall functionality.

So is there any suggestions regarding

Important documents to follow.
Opensource firewall projects that might be available to easily understand and start from scratch.

Anything more if I am missing

[cdenley]

All firewall solutions in Linux that I know of are merely frontends for iptables. I made a captive portal in python which pipes rules to stdin for the iptables-restore command. Works very well.

[credobyte]

Check http://www.ibiblio.org/pub/Linux/docs/HOWTO/Firewall-HOWTO - very interesting & useful material :)