IPFire 2.17 Core 92 / 3.0 Alpha 1 for linux full final free download
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.