Reusing Old Hardware
I had a Nokia IP120 that had a dead hard drive in it. For most of you who don’t know what a Nokia IP120 is, it is a small computer the size of a breadbox that has three network interfaces on it. It was primarily sold as a firewall running the IPSO operating system and Check Point VPN-1/FireWall-1. It also has mounting holes so the device can be mounted on the wall, which is a bonus for my wiring closet. Given the box is rather anemic in the CPU department and only has 128mb of RAM, I wouldn’t attempt to run a current version of Check Point on it. It does, however, run Linux with iptables just fine.
I’m not going to go into the specific steps I followed to make this system, but it did involve taking the drive out of the IP120, putting it in another computer, loading the desired Linux distribution on it, and configuring it for serial console prior to putting the drive back into the IP120. A lot of work, yes, and the machine is dirt slow for anything other than passing traffic, but it is good use of old, obsolete technology.
In addition to passing traffic, I can also load my internal DNS, DHCP, and TFTP server on it, not to mention an OpenVPN client. With the little use it gets, it won’t break a sweat. 
