Dedicated LAN server for ISP problem

I am trying to set up a internal LAN server for an ISP and I am having a problem. Its so the customers who use this ISP can choose to play a local game and we can have great control over who can access the game. The game in this case is Battlefield 1942.

The problem is that anyone who is not using the exact same subnet cannot see the LAN server. And there is obviously more than one subnet for the isp. The firewall is configured to allow ports 22000 and 14567 through and so that isn't the problem.
How do I fix this? Is there some particualy way to configure the router or firewall between the subnets so are to see the LAN server?

Thanks for any help.

is there and acl on any of the routers between the ISP and the costomers?? I know some ISP setups, like the one that Iwork for, have an extended acl in place between our backbone connections and out offices and our customers' routers. it looks something like this:

inet-------------
-
- (acl--extended)
-routers----------offices
-
-
-
customers

is it possible that the server is relying on broadcasts to find the server? in the client configuration, can you specify the server?

I'm not sure about BF 1942 but, with SOF II there was no way to play from the local LAN AND from the Internet at the same time. If I setup an Internet game and tried to connect from the LAN I got a parse packet error. If I setup a LAN game the game wasn't visable to the internet. I tried putting it in the DMZ with a 172.16.x.x address and a 192.168.x.x address. Both were natted to the internet through a PIX with static mappings. Basicly, Raven said you can't have a private network address, play from the internet, and play from another (or the same) private network.

The solution for me was to put the box on the outside of my firewall. That way it had a valid internet address, I could connect from my LAN (because I was natted to a public IP) and people could connect from wherever. I did get zone alarm to protect the box (which had a memory leak and required rebooting every two days or pings when up and up), and this does raise the issue of everyone being able to see the box but, setting a password might fix that.

Also, since this was SOF II my situation might not even apply..

I have the ability to play MOHAA through a pix static mapped nat with both inet and lan clients here. I will install bf1942 and let you know as soon as I can.


[edit] BF 1942 appears to work the only thing that I have found is that as matridom said above, you must sepecify a server ip from the client machine, unless you push the server through to gamespy or something.[/edit]


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