We have a matchmaker server that we use to connect two players in a game, which is accessible by the computers on the same network using the network ips, but something seems to be preventing the other computers from connecting to the server when we try to access the server over the internet. I have set up the server to use port 1235, and I have configured the router to direct traffic aimed at the public ip address, port 1235 to the machine in question. When I try to connect from any computer on the network, no packet arrives, but the packet definitely leaves the computer that is trying to connect... :(. I have tried [public ip]:1235 in firefox and a packet arrives, so I think I can rule out a firewall issue on the server or the router, so there must be some step that firefox is doing that my clients aren't right? Can anyone tell me what that is, or what else might be stopping the packets getting there? Forgive my newbieness about this please :) I have been using wireshark to monitor the traffic.

From reading around I have discovered that it might be that my router is incapable of properly handling lan requests for Wan addresses - how would I dteermine if that was the case?

Are you using TCP or UDP? If you're using UDP, are you using one socket to send and receive for each client?

I'm using Enet, which uses UDP, but I'm not sure under the hood whether thats using one socket to send and recieve per client. I can look into the code if required, but would that actually affect whether the client manages to send the packet out of the network and the packet arrives at the computer that runs the server?