Factorio Forums

Mods, if this is the wrong forum, please move it where you think it goes best. I've tried searching for any similar threads, without luck.
When my spouse and I (who share a LAN connection) try to connect to the same game hosted by a friend, only one of us can join while the other is completely unable to connect. The same goes for if someone tries to connect to a game we have running between our computers, even when external IPs are used by everyone to connect. Spouse does IT and friend is a coder, so they've narrowed it down to the fact that because we don't own a router that supports NAT loopback/reverse NAT (disabled via firmware "for security reasons"--thanks Sysco Linksys!), we can only either play with each other via LAN, or one of us can join the friend's game and play at a time.

My question is, when will some kind of multiplayer support be available for those unlucky enough to have nonNAT loopback/non-reverse NAT routers or is there already some sort of workaround so we can finally all play together?

Factorio now supports IPv6, which does not need NAT loopback.

Does your router support IPv6?

Assuming you did use different ports for each factorio behind NAT.

There are still few options available.
You can overkill it and use a VPN.
You should be able to redirect traffic(s) to each other in some routing table
| At least Linux can do that. Just add a prerouting rule of "Going to my external IP + factorio port? Then go to my other factorio instead".
| So.. harder to set up, lower latencies I guess.

I'm not sure if its the same issue:

-Run server on laptop, change port to non default to avoid conflicts with PC so the remote player can have a connection to both. set router to forward all unassigned to laptop (DMZ).
-Remote friend connects fine, no issues.
-Connect to laptop server from PC, Connects fine, but fails to connect to the remote friend.


My guess: Laptop tells the remotePC my local IP. Laptop tells my PC the friend's correct IP. Either UDP holepunch fails or the friend tries to accept connections from the wrong IP

How does factorio connect to the non-server clients? is UDP holepunch actually involved?

Update on behalf of Mystil.

Found a network issue here that was apparently preventing us from both playing Factorio with a remote client. All is well now.