IPFire is an open source operating system that has been designed from the ground up to act as a dedicated, secure and flexible firewall system based on some of the best Linux technologies, such as iptables, OpenSSL and OpenSSH.
Distributed as a 32-bit ISO image
This tiny OS can be downloaded via Softpedia or from its official website (see link above) as a single, installable only CD ISO image of approximately 150MB in size, tagged only for the 32-bit (i586) instruction set architecture. While the distro will boot and install on 64-bit hardware platforms, it will only accept 32-bit applications.
The beautifully designed and well organized boot menu will allow you to directly and permanently install the distribution on a local drive. In addition, you’ll be able to install the OS in text mode, perform an unattended installation, run a memory diagnostic test with the Memtest86+ utility, as well as to view detailed hardware information with the Hardware Detection Tool (HDT).
Very easy-to-use text-mode installation program
The entire installation process is text-based and will require the user to only select a language (supported languages include English, Turkish, Polish, Russian, Dutch, Spanish, French and German), accept the license, and partition the disk (supported filesystems include EXT2, EXT3, EXT4 and ReiserFS).
After installation, it is a must to select a keyboard layout and timezone, enter the machine’s hostname and domain name, enter a password for the root (system administrator) and admin accounts, as well as to configure the network (includes DNS, Gateway, IP Address, Drivers and Network Card settings).
Summing up, IPFire is one of the world’s best open source firewall distributions of Linux, engineered to deliver state-of-the-art firewall, VPN gateway and proxy server components. Its design is modular and flexible, which means that its functionality can be extended through plugins.