SBS 2003 problem

[chairbornranger]

So I'm setting up this SBS server for a friends company, and I can't get it to pass through its internet connection. We've configured it to handle DHCP, so it assigns IP's to computers, it gets its own IP from the router connected to one of its NIC's. So it has 2 nics in the server, one has a direct connection from the router, the 2nd nic goes out to the switch with all the workstations on it. The workstations get IP's just fine from the server, but if you try to ping the router from one of the workstations it doesn't make it back through the Server. What am I missing??

The server also has DNS running on it... The server itself can get out to the internet, but none of the workstations. I know theres some specifics i've left out, some on purpose, but ask if you want to know where I've configured some things.