Port forwarding for a Arma Reforger server
Reforger needs two things forwarded, both UDP: the game port and the Steam query port. What sets it apart is that the query port has its own fixed default instead of sitting a set distance from the game port.
Your setup
Choose the firmware family rather than your exact model — every router in a family shares the same menus.
Out of the box it is 2001. If you changed that, use whatever you set in bindPort in config.json.
The local address of the computer that runs the server. Find it with ipconfig on Windows or ip addr on Linux; it will begin with 192.168, 10. or 172.
Open these
Your firmware takes ranges, so each line here is one rule.
- 2001 UDP
- 17777 UDP
2001UDPGame trafficbindPort. Reforger ships with 2001, though most rented panels remap it — use whatever your config file actually says.17777UDPSteam querysteamQueryPort, a fixed default that does NOT move with the game port.
Do not open these
Good news: this game has no remote-admin port that could be exposed by mistake. Forward the ports on the left and stop there.
Step by step: your router
- 1
Give the server a fixed local IP
A forwarding rule targets a single local address. If the server comes back from a reboot with a new one, the rule quietly points at an empty address — which is how forwards seem to "break by themselves".
On this router:look for DHCP Reservation, Address Reservation, Static Lease or Manually Assigned IP
- 2
Open the router admin page
From a device on the same network, open one of these in a browser:
- 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
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
Create one rule per line
a description field, if there is one External / WAN / Public / Service port Internal / LAN / Private port Protocol Internal IP / Device / Server IP Arma Reforger 2001 2001 UDP your server’s local IP Arma Reforger 17777 17777 UDP your server’s local IP Use the same number for the external and internal port. You can make the external one different, but then every player has to connect on that new number, so keep them identical unless you have a specific reason not to.
- 5
Let the server through its own firewall
The router is now sending traffic to the right computer, but that computer can still turn it away. Windows Defender Firewall is the usual offender: it blocks a newly installed dedicated server by default, and from outside that is indistinguishable from a broken forward.
Take it with you
Arma Reforger — port forwarding rules ------------------------------------- 2001 UDP -> <server local IP> 17777 UDP -> <server local IP>
Check whether it worked
Always test from outside your network. A connection from another device in the house proves nothing: that traffic stays on your LAN and never passes through the rule you just created.
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The usual mistake
Since the query port does not follow the game port, moving the game port and assuming the other one moved too leaves you missing from the browser. Reforger is also the likeliest game to have a real port that differs from the stock one, because rented panels often remap it. Take the number from your configuration file rather than from any default, ours included.
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Skipping port forwarding
Players pull Reforger's mods from the Workshop at join time, at whatever speed your upload allows. On a home connection, that is typically why a server that works on paper feels broken in practice.