pfSense is a free, open source customized distribution of FreeBSD tailored for use as a firewall and router. In addition to being a powerful, flexible firewalling and routing platform, it includes a long list of related features and a package system allowing further expandability without adding bloat and potential security vulnerabilities to the base distribution. Being based on the fabulous m0n0wall foundation pfSense provides almost all of m0nowalls' features and several important features on top of that.
500 MHz CPU AMD Geode LX800
256 MB DDR DRAM
512 MB Internal Flash Memory
3 LAN ports (10/100Mb/s)
2 USB 2.0 ports
1 Console port