getting two comps to work inside NAT firewall/router

[Phleem]

For others that want to play Civ 4 on two computers inside a NAT firewall router, like the ones about twenty million people in the US own, here's what I had to do.

I ran into a series of problems, from the LAN setup not working, to finally getting it to connect between the machines on the local IP address, and then having it lose connection as soon as the game started.

I had gone through and opened up the 2056 ports on both machines, though now I suspect this may not be required.

Then I gave up on the LAN setup and just focused on getting the Direct IP setup to work.

The main solution appears to be when you connect in the second machine to give it the external NAT address of the hosting machine. To do this you'll have to set up port forwarding in your router for the 2056 port so that any traffic that comes to the external IP address on 2056 is routed to that machine.

You can see the external NAT address by going here: http://www.whatismyip.com/

There were clearly some pretty serious networking software errors made along the line here. I suspect maybe they need a way to really turn off ever trying to use the external addresses for people that just want to play within a LAN.

 

[drsparnum]

I have two PCs using one router and one cable internet connection. Normal internet use has been running just fine. However, I hit a snag when trying to have the two computers play an online game (Civ 4) together. I can get the two PCs (A&B) that are on the router to play together just fine (internet or LAN). However, when we tried to work in a third computer (PC C) into the mix, my friends computer who lives two states away, has a different ip address and obviously isn't attached to our router - it didn't work.


I think it is because both computers (PC A and B) look like they have the same ip address (if I go to whatismyip.com it tells me the same ip address on either PC). This is supposed to be a security "feature" since the router transmits its ip address, protecting your PC's ip address. Here it seems to be causing a problem. Does anyone know a workaround for this - short of paying for a second cable internet connection and cable modem? Don't let me sway you that the ip address is the cause of the problem, either. It could be something else. That's just what I think the problem is.

 

[kgober]

the quick answer is, set all the computers that are sharing a public ip address (that is, all of the computers that are on the same NAT) to use a unique port (they can't all use 2056 at the same time).

check the pitboss sticky thread for details.

-ken

 

[Doomed_UK]

or use hamachi which will give everyone thier own second seperate IP address.

It was the only way I can host a game and have other machines on my LAN and remote machines join me at the same time. (The machines on my LAN share the same router).