6112 is generally WarCraft 3.
--
Try this:
Under port-forwarding, create a service and call it WC3. On this service choose an IP address that none of your current computers are using. Set the port range to 6112-6118. If you can't do that, then just use port 6112. Once done:
Go to Network Connections.
Right click your current connection (LAN or High Speed Internet, not the gateway).
Go to properties.
Under general, scroll down to Internet Protocol (TCP/IP).
Click on it and go to properties.
Click on "Use the following IP address:"
For IP address, type in the same one you typed on the service.
Now, go to "Run" and type "cmd". Then type "ipconfig /all"
Take note of the following items:
-Subnet Mask (usually 255.255.255.0)
-Default Gateway (usually 192.168.1.1)
-DNS Servers
Input these in the remaining boxes on the Internet Protocol TCP/IP properties box.
So right now, you have just selected an IP address which forwards the ports 6112-6118 (if you used a range of ports). You have also set your computer to use this IP address. So when you play, the ports will be forwarded.
If this DOES NOT work, then you probably have a modem or another router which adds another gateway (it "masks" your IP addresses) to the internet. So what am I saying? I'm saying that the ports you forward from the linksys router are not necessarily forwarded through the other router or modem, thus they get masked and you can host.
Also, if you run Windows Firewall, make sure to add WarCraft III as an exception or completely turn it off when you try to host.