Necessary Ports To Forward

[Sollace]

To fix the Connection failed problem on multiplayer, what ports are necessary to forward?

[Kronovan]

I've read posts in different forums (Steam, TopWare Interactive and Inside Two Worlds) that have varied, 1 stating you only need to redirect
UDP ports 17171 and 17771

to others that have said you need to redirect
TCP and UDP port for the ranges 17171-17172 and 17771-17772.

I just went with the latter to be sure. However, you should be aware that there appears to be issues with the Warnet America server. I can connect seemlessly to the Warnet Europe server, but get a connection error whenever I attempt to connect to the America server. This seems to be a problem for many players. I've seen other threads where they discuss matching your NAT with the Warnet America server, but it's been so long since I've done anthing like that, that I haven't gone there yet.

If your goal is only to play with friends, it's easier to just use a VPN service like Hamachi and host through your own game. There's a simple guide in the Community Guides page describing how to do it.

[Lesh]

Hamachi does not work nor a VPN service. You need to enable edge exceptions in your firewall. I take it that you are using windows 7. Quite a few people have had this problem as well. Here is a link on youtube to show you how: http://www.youtube.com/watch?v=IVVwTAWZmjM

[travisbrewer]

This still doesn't work for me. I enable the UDP ports and enabled edge exceptions, and tried Hamachi....still nothing. Thanks for trying though guys.

[Sollace]

Well, further comments on this post are, admittedly, a surprise. Have you ensured you selected TCP/UDP for your ports. After port forwarding the ports given in the original reply- I recall being fine for connecting to multiplayer.