Two computers cannot play using lobby: Connection Error

[urgood2]

I have two computers connected to the same router.

If I use the IP method to play multiplayer on those two computers, everything works fine.

But if I go into the lobby, I can see the other computer's hosted game but cannot join it. Instead, the message "Connection Error" appears.

This is the same with both computers; that is, everything is the same no matter which computer I use to host the game.

I'm wondering what is wrong.

1st computer:
Desktop, Win XP SP3, ram 513Mb, cpu 3.0Ghz, NVidia GeForce fx 5900xt

2nd computer:
Laptop, Win Vista SP2, ram 2GB, cpu 2.0Ghz, ATI Radeon Xpress 1250

[NoQ]

If you have a router and your PCs are therefore behind a NAT, and you're doing port forwarding (since if you don't, hosting for lobby won't work at all), then your other PC is trying to connect to the external (router's) IP and the forwarded port, but the port is not forwarded inside your network, but only outside, so nothing can work.

[Zarel]

If I use the IP method to play multiplayer on those two computers, everything works fine.

But if I go into the lobby, I can see the other computer's hosted game but cannot join it. Instead, the message "Connection Error" appears.

You have a bad router. Get a better router.

If you have a router and your PCs are therefore behind a NAT, and you're doing port forwarding (since if you don't, hosting for lobby won't work at all), then your other PC is trying to connect to the external (router's) IP and the forwarded port, but the port is not forwarded inside your network, but only outside, so nothing can work.

what is this i dont even

[NoQ]

Hmm, i'm still learning

What i was saying is that, for example, under linux/iptables when you forward packets coming to external interface to some internal ip/port, you need extra efforts to forward the packets coming to the same place through internal interface to the same place, don't you?

[Zarel]

What i was saying is that, for example, under linux/iptables when you forward packets coming to external interface to some internal ip/port, you need extra efforts to forward the packets coming to the same place through internal interface to the same place, don't you?

It gets a bit complicated, yes, but a good router should be able to handle it.

[urgood2]

Hmm, I don't know whether the router does NAT for me, as it does not appear in the router settings.

If one of the computers did DMZ, would the multiplayer game work through the lobby?

[Buginator]

If your router is lacking, then your only choice is to join by IP, or enter a hostname on all client computers that map to the host's INTERNAL IP. (you need to edit the hosts files for this on windows)

[urgood2]

Thank you. I don't think I want to go that far.
I guess I'll just use IP for a while.