Since 2005 there has been an immense increase in brute force SSH attacks and though Linux is pretty secure by default, it does not stop evil programs from indefinitely trying to login with different passwords.

How do I restrict the number of connections used by a single IP address to my server for port 80 and 25 using iptables?

Alot of people are freaked out by IPTables and find it hard to understand. However, once you get the grasp of it the basics are easy. This document will serve as a basic how-to on using iptables.

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.

Vuurmuur is graphical front end for famous firewall software iptables. You can make complex firewall rules in simple steps. Vuurmuur supports traffic shaping, has powerful monitoring features, which allow the administrator to look at the logs, connections and bandwidth usage in realtime.

Many organizations face a productivity problem with employees who abuse chat programs like MSN Messenger. Some IT departments are instructed to block this kind of traffic for users who either abuse or simply don't require the software.

Today I will show you the iptables rules I set on my main personal computer, with detailed comments about why I came to use these rules after several years of Linux desktop usage.

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.

In this article I will show how to prevent brute force attacks with Fail2ban against your SquirrelMail Web login using the Squirrel Logger plugin.