Port forwarding for a Space Engineers server
Space Engineers needs one UDP port, which handles both play and server-list registration. That is all it takes to be reachable.
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 27016. If you changed that, use whatever you set in ServerPort in SpaceEngineers-Dedicated.cfg.
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.
- 27016 UDP
27016UDPGame trafficGameplay and server-list registration.
Do not open these
These are admin sockets. Many guides put them in the same list as the game ports, but forwarding them exposes a remote console for your server to the whole internet.
8080TCPRemote APIThe VRage remote API. Useful, but it is an administrative endpoint — reach it over a VPN.
For remote administration, connect to the machine through SSH or a VPN and use the port locally from there. Nobody else can reach it that way.
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 Space Engineers 27016 27016 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
Space Engineers — port forwarding rules --------------------------------------- 27016 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
The remote API on port 8080 is separate from that, and you should not forward it. It is a truly handy admin interface, and that is exactly why putting it on the open internet is a bad bargain. Use a VPN or an SSH tunnel to reach it and keep the port closed.
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Skipping port forwarding
Every block is simulated server-side, so a world with big grids runs out of CPU well before bandwidth. When the server begins to stutter, the ports are not what needs changing.