"If, like many people, you've started to experiment with enabling, configuring, and using, IPv6 it might not have crossed your mind to update your firewall. This could lead to surprises if you're unlucky. Read on for a simple overview. The standard userspace firewall tool upon Debian GNU/Linux is iptables.

"I run a Postfix-based mail server that services a few hundred users with an average load of a couple of thousand legitimate messages a day -- but thanks to spam, the actual load on the server is much higher. I use Realtime Blackhole Lists (RBL) and Distributed Checksum Clearinghouse (DCC) clients on Postfix and SpamAssassin to reduce the impact of spam."

Estimates say that spam makes now up for 80 - 90% of all emails, and many mail servers have difficulties in managing the additional load caused by the latest spam, and spam filters such as SpamAssassin do not recognize large parts of that spam as they did before.

UFW or Uncomplicated Firewall, is a text based firewall that works with iptables. UFW is designed to be an easier way to manage a firewall from the command line. Whether this is easier than learning iptables or not, you can decide. But UFW comes partially set up when you install Ubuntu.

The Zimbra install suggests that you do not want to use a firewall. Actually, this is not the wisest decision, you should have a firewall. Ubuntu 8.04 (Zimbra does not support 8.10 yet)

The UFW has a GUI front end that you can add to it to provide an “easier” method of working with the firewall. You will see that it will be installed and available using System/Adminstration/Firewall administration. The interface is set up for several different options.

FireHOL is a stateful iptables packet filtering firewall configurator. It is abstracted, extensible, easy and powerful. It can handle any kind of firewall, but most importantly, it gives you the means to configure it, the same way you think of it.

Setting up a firewall for IPtables can be rather difficult, especially if its your first time. A firewall is something you need to have, whether you are just trying to keep hackers out, or trying to meet a requirement such as PCI compliance, or HIIPA compliance. Luckily the folks at rfxnetworks, created a CLI based configuration for IPtables.

Have you ever wanted to configure a personal firewall for your GNU/Linux box, but were scared of the complexity of iptables? Well, I might not be able to make you a security expert, but I can show you a tool that will help you to configure your personal firewall the easy way. The secret? Firewall Builder (also known as fwbuilder for short).