Installing and configuring Linux Firewall

Protect your servers in the Demilitarized Zone, and run intranet too.

For home, office and pleasure

by Jan K. Labanowski,


When I decided to get DSL and get static IP addresses to my basement, I had to protect my babies behind the firewall against the hackers. I bought the computer which I use for the firewall in the surplus store of OSU for $25. It has a 2 Gig drive, and a 133 MHz non-MMX pentium. And I never saw an average load on it above 0.05. The 486 would probably do, but you probably cannot get them anymore. When you install Linux, note that you do not want to install a lot on the firewall, but you want to install kernel and firewall (iptables). You need networking support, but this is it. No compilers, no develpment, no graphics, publishing, etc., etc., Just have a barebone Linux, networking, and firewall.

The script has a lot of comments. The script itself is short, but comments are 10 times the actual commands. I hope you will learn something out of them. When you save files, rename them by skipping ".txt" extension.

Please help me fix the bugs and problmes which you see with these files, so they are useful. Just send me e-mail to

Jan Labanowski,