I thought I'd take a shot at building a firewall/router out of an old machine my dad had sitting around. It doesn't take much of a machine to do that.
Here's the hardware we've got for it:
An old Pentium Pro 200
a 3GB hard drive (that seems such an odd size)
128MB of ram (made from 4 32MB sticks!)
an old Toshiba CDROM
my old Farallon NIC (a forced purchase while living in Family Housing at UofO)
and a relatively new US Robotics Courier v.Everything v.90 56k modem
Unfortunately, the modem shipped with a dead power brick. Since the modem was made in '94, I suspect it wasn't really "new" but "like new". I bet they had a closet full of the boxes the modems came in and the modems themselves were probably pretty hands-off. They pulled them out of the box, plugged them in, and never touched them again. The guys selling them (from downsizing dial-up ISPs) probably dusted them off, blew them out, slid them back into the pristine boxes, and sold them on ebay.
Anyway, here's the plan. Try out a few Firewall/Router Linux distros.
I have the latest versions of: Mandrake MNF, SentryCD Firewall, Linuix, and IPCop
With any luck, one of them will work. I think the Mandrake one looks promising. It states a minimum requirement of a 300mhz machine which might be a problem. There's no need for a GUI interface on the actual machine. I hope to have it be completely remotely driven via html configuration (like a "regular" router). It seems to have the fanciest interface out of the four (although that's not necessarily important).
I'm looking at a week down-time waiting on the replacement power supply though. This might be a good time to install MythTV on my dad's other machine I'm working on. I expect this to go smoothly, but we'll see... that's another story altogether.
Links of interest:
Mandrake MNFSentryCD FirewallLinuixIPCop