by tom » Fri Nov 26, 2010 3:55 pm
The port forwarding instructions is only required when using the "Direct Connect" method. In this method, the host enables port forwarding on port 9877 (UDP), then the clients (your friends) connect to your server by clicking on the "Direct Connect" option and typing your IP and PORT.
Most likely, the reason why your friends can't join (when using the Server Browser) is because your windows firewall is blocking incoming connections (the server browser uses an alternate protocol to establish connections that isn't dependent on port forwarding). Try temporarily disabling the entire Windows firewall and see if it works. If it doesn't help, then most likely your router is one of the few that is incompatible with the ICE protocol that Clones uses.
There are plans to improve the reliability and probability that a network connection succeeds, and this will be made available in a future patch. Perhaps after one of these future patches, you will be able to host multiplayer games without problems.