[0.12.1] MP connection issues

[FalcoGer]

A friend of mine set up a server in a datacenter with factorio, version 0.12.1 for linux on port 34197. All ports forwarded. Either one of us can connect without problems. When the second player tries to join the server would respond with: "The following peers are not responding: Unknown player" after which the server will drop the connection, not even down-/uploading the map. Funny enough it shows that port 34198 is used for the side that couldn't connect, but 34197 for the player who is connected already. Both of us have then forwarded 34197-34199 udp&tcp in our local network access tables. Still doesn't work with the same effect. Connection to any other port than 34197 results in "No host found", which makes sense (for once).
When I put myself in the DMZ in my local network, I can connect as first or second. But when I'm the first one, he gets the same kick for not responding. When I join second, everything is well.
There seems to be a use of undocumented ports that need to be forwarded in order to play with multiple players...

Another issue is that when hosting locally, he can not join my game over my external ip, even though I have the port forwarded in my router. Trying a different port in the config doesn't solve the issue. Hamachi works fine, except this: https://forums.factorio.com/forum/vie ... =7&t=14082 where I have to set stupidly high latency just to get over the first couple of seconds where the map is uploaded and the ping messed up.

(Been using external ip from http://myip.is)
(Yes, i know how to forward ports on my router, and I'm certain I did so correctly.)
(Yes, we quadruple-checked the ip for typos.)
(Yes, we tried turning it off and on again. )

[slpwnd]

At the moment there are limitations to MP connections. Basically it is a pure peer-to-peer at the moment. Because of NAT-punching sometimes player with private IP addresses can play together as long as they initiate the communication via a public IP client / server.

However if the server and one of the clients are on the same private network then the connection for other player won't be possibly. This is because server hands out to the 2nd client a private IP address of the 1st client and there is no way for the 2nd client to communicate this way with the 1st client. The solution for now is to use Hamachi as you mentioned. There is a fix in 0.12.2 that should fix the connection dropouts.

We discussed this briefly and implementing traffic relay via the server should not be too difficult actually. We will see how it goes but it is possible that this will get implemented during the 0.12 stabilisation process. If not then 0.13 at latest=)) Hope this helps.

[kovarex]

The issue has been (probably) resolved for 0.12.4, as we made the option to resend the packets through server.