SOHO firewall appliances have become so inexpensive that it almost doesn't make sense to run a PC, even an old one, as just a firewall anymore. Power, noise, heat, etc. I have replaced all the firewall PCs I used to use with simple routers or, where VPN connections are needed, either with Snapgear Cyberguard VPN-capable routers or Linksys BEFVP41s for WANs tunnelled over the Internet. That Endian distro did look interesting though!