Router, IP games, LAN and outside

[Rediranch]

I have a router, for cable internet, and two machines on the router sharing internet. I have a friend out of state that I play games with, using our IP's.
To do that on my router, I have to enable the DMZ host, I already know.

Here's the problem. When I host a game, my out-of-state friend can connect, using my assigned internet IP, but when a friend on my router also tries to connect, we have to use the local ip for my machine. This works initially, but by the time you can load the game, it rejects one or the other of them.

We changed, so my friend on the router hosts, and the out-of-state can get in, but when I try to join, using the local IP for the other routed machine, it also either dumps me or the out-of-state person. This test tells me that it's the idea of using two different ip's, one from outside the router, the other within the LAN, that is causing the problem.

So, how can I make a machine, local, go outside my router, and come back in using my ISP assigned IP?

[BipolarBill]

A better idea would be to disable DHCP, connect the modem directly to the game server and add a NIC for LAN play. Use the Router as a hub while playing.

[pinkey777]

Another issue may be Key authentication.

Are the games you play ones that have to authenticate the Key to the master server, Like Quake 3?

Does everyone have their own key? You can get away with using the same key more than once on a LAN, but internet connected machines must authenticate with the master server. The master server will reject multiple use of the same key.

That's why I had to buy 3 copies of Quake 3. So I could have friends over and play as a team over the internet.

[Rediranch]

Good Idea, Bill, took me a sec, but I see what you are saying....the NIC hooked into the modem will have the ISP's assigned IP, and the other local can use that IP, and the remote player will also. I'll try it out.

Pinkey, one of the games doesnt require key auth (Total annihilation), and another does (TA Kingdoms), so I've run into that problem already.

Thx both.