strange request

Hi, here is a strange question. A customer has a small network, DSL, Linksys router, Sonicwall Firewall, switch, Windows 2000 Server AD Domain, 10 workstation of 2K Pro, XP, Mac OSX.

Server has 2 NICS of 192.168.1.2 and 3.

Problem: the sonicwall firewall only has 5 user licenses so only 5 computers can connect to the internet.

Desired solution by the customer is to use the 2 NICS on the server to act as a router, so that the other workstations can use one server NIC as the gateway, while the other NIC then sends the connection to the switch, firewall, router, and to the internet.

I have never seen this type of setup nor this type of request.

Can anyone give me some ideas, URL links, or other possible options? Thanks.

Michael R.