Did you ever get anything from anybody? I have the same question. Only I am trying to get 10 clients connected to our own server on our own LAN. I understand the port things and why there is a problem. However, it seems to me that during development Taldren did not have thier server running and reporting to GameSpy or Dynaverse. And then they started up their clients, connected to GameSpy or Dynaverse and then chose the test server and joined. They had to be able to connect thier local clients to a local server. Or, they had a local access server that took the place of Dynaverse and GameSpy.
If they had a local access server, how do we get ahold of that? If they didn't then they must have had some sort of command line paramter for the client that told it to look locally for a server and not through an access server. Maybe something like this: SFC3.exe -local
If a local client is talking to a local server then the local IPs are different so the port numbers don't conflict anymore. Somebody has to know how they did this?
I saw a post on a Descent web page where a guy wrote a local access server. With just a little bit of help with regards to whom talks to whom on what port and what is exchanged, I could do that.
I can tell you how far I got with the port forwarding and a single IP. I forward the server ports you listed and it runs fine. I then forward the client ports to my first client machine. It connects to the access server and I see my server listed and can join. I chose my fleet and I am in. Then I go into my router and forward the client ports to my second client, start it up and it gets to the access server, sees my game server, I join, select my fleet and I am in. Both clients can run around the universe and do things with the AI. But when we both try to attack the same AI the client who the ports are no longer forwarded to, is dropped out and sent to the nearest starbase; with appropriate repute I might add. So, if you and your friend just want to run around and not be in the same battles this should work for you.
I got 10 folks to worry about though and they really want to fight together, and against each other, in the same battles.
If you learn anything useful at all, please let me know.