This was very helpful information:

Call this entry CSS1

it should be like so

Check the enable box
Service name: CSS1
Incoming ports: 27020 – 27039
Destination IP Address: “Your Internal IP here, for example 192.168.2.4”
*Destination ports: 27020 – 27039
Port type: Check TCP

Press submit

Now we need to create another, this time call it CSS2:

Check the enable box
Service name: CSS2
Incoming ports: 1200 – 1200
Destination IP Address: “Your Internal IP here, for example 192.168.2.4”
*Destination ports: 1200 – 1200
Port type: Check UDP

Press submit

Now we must make a final one, we will call it CSS3:

Check the enable box
Service name: CSS3
Incoming ports: 27000 – 27015
Destination IP Address: “Your Internal IP here, for example 192.168.2.4”
*Destination ports: 27000 – 27015
Port type: Check UDP

Courtesy of FPSBanana, a site that seems to live on in Google’s cache.

Server config generator is here…

The server is up, by the way 🙂

–Nat