How to port forward a Arma Reforger server
Reforger needs its game port on UDP plus the Steam query port. Unlike most games on this list, the query port is a fixed default rather than an offset from the game port.
Your setup
Pick the firmware family, not the exact model — the menus are identical across a range.
Default is 2001. If you changed it, it is the value of bindPort in config.json.
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.
- 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
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
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
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
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 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
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
Arma Reforger — port forwarding rules ------------------------------------- 2001 UDP -> <server local IP> 17777 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
Because the query port does not follow the game port, changing the game port and assuming the rest moved with it leaves you invisible in the browser. Reforger is also the game where the stock port and the port your provider actually configured are most likely to differ — rented panels routinely remap it. Read the value out of your configuration file rather than trusting any default, including ours.
Not forwarding at all
Reforger's mod system pulls content through the Workshop on join, and the transfer speed your players see is your upload speed. That is the usual reason a technically working home server feels broken.