Linux Know-How provides a collection of introductory texts on often needed Linux skills.


David Rudder wrote this original version of this Firewall-HOWTO, now over four years ago, and I'd still like to thank him for allowing me to update his work.

I'd also like to thank Ian Gough for kindly assisting a this dislexic writer.

Firewalls have gained great popularity as the ultimate in Internet Security. Today firewalls are a part of almost every networking device. Like most hot subject they are also often misunderstood. This HOWTO will go over the basics of what a firewall is and how to set one up.

I am using kernel 2.2.14 and RedHat 6.1 to develop this howto so the examples here are based on this distribution. If you find differences in your distribution, please email me and I'll update this howto.


Any feedback is very welcome. PLEASE REPORT ANY INACCURACIES IN THIS PAPER!!! I am human, and prone to making mistakes. If you find a fix for anything please send it to me. I will try to answer all e-mail, but I am busy, so don't get insulted if I don't.

My email address is

Last Update: 2010-12-16