How to port forward a Space Engineers server
One UDP port carries both gameplay and the server-list registration. That is all a Space Engineers server needs to be reachable.
Your setup
Pick the firmware family, not the exact model — the menus are identical across a range.
Default is 27016. If you changed it, it is the value of ServerPort in SpaceEngineers-Dedicated.cfg.
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.
- 27016 UDP
27016UDPGame trafficGameplay and server-list registration.
Do not open these
These are administrative sockets. Plenty of guides list them next to the game ports; opening them puts a remote console for your server on the public internet.
8080TCPRemote APIThe VRage remote API. Useful, but it is an administrative endpoint — reach it over a VPN.
If you need remote administration, reach the machine over SSH or a VPN and talk to the port from there. The port stays closed to everyone 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 Space Engineers 27016 27016 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
Space Engineers — port forwarding rules --------------------------------------- 27016 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
The remote API on port 8080 is not part of that, and should not be forwarded. It is a genuinely useful administrative interface, which is exactly why exposing it to the internet is a poor trade — reach it over a VPN or an SSH tunnel instead and leave the port closed.
Not forwarding at all
Space Engineers simulates every block on the server, so a world with large grids becomes CPU-bound rather than bandwidth-bound. When the server starts stuttering, the port configuration is not what needs changing.