How to port forward a Factorio server

One UDP port. Factorio has the simplest networking requirement of any game on this site, and there is no query port, no secondary socket and no protocol split to get wrong.

Your setup

Pick the firmware family, not the exact model — the menus are identical across a range.

Default is 34197. If you changed it, it is the value of --port.

The private address of the machine running the server — ipconfig on Windows, ip addr on Linux. It starts with 192.168, 10. or 172.

Open these

This firmware accepts ranges, so each line below is a single rule.

  • 34197 UDP
  • 34197UDPGame trafficOne UDP port, nothing else. Factorio is the simplest forward on this list.

Do not open these

This game has no remote-administration port to get wrong. Forward only what is listed on the left and nothing else.

Step by step: your router

  1. 1

    Give the server a fixed local IP

    A forward points at one address. If the server picks up a different one after a reboot, the rule silently starts pointing at nothing — this is why forwards "stop working" on their own.

    On this router:look for DHCP Reservation, Address Reservation, Static Lease or Manually Assigned IP

  2. 2

    Open the router admin page

    Try these addresses in a browser on the same network:

    • 192.168.0.1
    • 192.168.1.1
    • 192.168.2.1
    • 10.0.0.1

    Almost always printed on a sticker on the router itself.

  3. 3

    Find the port forwarding page

    Port Forwarding, Virtual Server, NAT, Applications & Gaming, or Port Mapping

    Vendors use at least six names for the same feature. Whatever it is called, the page you want is the one asking for a port, a protocol and a device on your network. If the external and internal port fields both exist, set them to the same number.

  4. 4

    Create one rule per line

    a description field, if there is oneExternal / WAN / Public / Service portInternal / LAN / Private portProtocolInternal IP / Device / Server IP
    Factorio3419734197UDPyour server’s local IP

    External and internal port are the same number here. Changing the external port is possible, but then everyone connects on the new one, so keep them matched unless you have a reason.

  5. 5

    Let the server through its own firewall

    The router now sends traffic to the machine, and the machine can still refuse it. Windows Defender Firewall in particular blocks a freshly installed dedicated server by default, which looks exactly like a failed forward.

Take it with you

Factorio — port forwarding rules
--------------------------------
34197  UDP  ->  <server local IP>

Check whether it worked

Test from outside your own network. Connecting from a machine in the house proves nothing — that traffic never leaves the LAN and never touches the rule you just wrote.

What usually goes wrong

Many people never need to forward anything, because Factorio's matchmaking service can often negotiate a connection through both ends' routers by itself. If your friends can already join a game hosted from your client, forwarding will not make it faster or more reliable. It becomes necessary when you move to a headless server, which does not use matchmaking.

Not forwarding at all

A headless server keeps the factory running while you sleep, which for Factorio specifically is a large part of the appeal. That is the point at which the port stops being optional.

Check whether your Factorio server is reachableHow much RAM a Factorio server needsFactorio server hostingAll games
Support & Help