Port randomization issue when hosting

[Impatient]

Hello fellow engineers!

I have a problem when hosting a game. I assume its port randomization. I list everything I know.


The problem:

• After starting to host a game, I get this popup in game:
  "Unable to determine external IP address. Other players ..."

This is the relevant (I believe, after what I read on the forums) part of the factorio log:

log

6164.304 Info ServerRouter.cpp:668: Asking pingpong servers (pingpong1.factorio.com:34197, pingpong2.factorio.com:34197, pingpong3.factorio.com:34197, pingpong4.factorio.com:34197) for own address
6164.357 Info GameActionHandler.cpp:5088: UpdateTick (36001) processed PlayerJoinGame peerID(0) playerIndex(0) mode(connect)
6164.541 Warning ServerRouter.cpp:543: Received own address message reply with conflicting address (got IP ADDR:({213.147.167.97:53633}), expected IP ADDR:({213.147.167.97:12730}))
6164.541 Warning ServerRouter.cpp:543: Received own address message reply with conflicting address (got IP ADDR:({213.147.167.97:21448}), expected IP ADDR:({213.147.167.97:12730}))
6164.551 Warning ServerMultiplayerManager.cpp:662: Determining own address has failed. Best guess: IP ADDR:({213.147.167.97:12730})

Technicalities:

• I am on win10, steam.
• I only use windows firewall. It has allow rules for Factorio for both public and private networks.
• I use a mobile LTE broadband connection. The device is a D-Link DMW-222 usb modem.
• I am in Austria. The ISP is "Simfonie", which uses the A1 mobile network.

Observations:

• When I use a webpage, which shows me my IP and port ( I used https://www.myip.com/ ) the port changes every few page reloads.
• The IP address shown in the factorio log is different from the IP address shown in ipconfig.
• I have not had this problem when I used a broadband cable connection from a different ISP.

My assumption (please correct me if I am wrong):

• The problem is port randomization.

The questions:

• How can I disable port randomization?
• How can I determine what is responsible for the port randomization (the ISP, the LTE modem, windows 10, ... something else) ?

[Rseding91]

The issue is going to be with the ISP and or the LTE connection. They are not designed for this kind of thing and you'll run into this sort of issue. You can still have friends join you through steam networking/steam invites but you won't be able to host directly on the browse-games GUI.

I have never heard of any mobile-internet connection that didn't have this issue.

[Nidan]

If your modem is more than a pure modem, e.g. it has some kind of firewall or NAT or also acts as a router, check if you can configure port forwarding rules for it. If you can't or that doesn't help, you'll have to contact your ISP.