Running a server/Connectivity
Once you have got your server up and running and you want players to connect to it over the Internet it is likely that your server will be behind a firewall, a router with a firewall, or a router using network address translation (NAT). This is likely to mean you will require some additional configuration of one or more of these in order to make your server world visible.
The most likely scenario particularly for game servers at residential properties is a router using network address translation. This is where one public IP address is assigned to a NAT router at home, of which is then shared between one or more computers/devices using a private address network. The easiest way to determine if this is the case for you is to do the following:
- Open a command prompt or terminal environment on your system.
- Submit command: ipconfig (on Windows) or ifconfig (on Linux).
- Take note of the numbers to the right of the IPv4 Address row.
Ignore any network device that shows one of these address ranges, because they are not connected to the Internet anyway:
- 0.0-255.0-255.1-254.
- 127.0-255.0-255.1-254.
- 169.254.0-255.1-254.
Check if your IPv4 address is within the following ranges:
- 10.0-255.0-255.1-254.
- 172.16-31.0-255.1-254.
- 192.168.0-255.1-254.
If this is the case you are definitely behind a router using NAT. You will need to configure port forwarding on your router in order to make your game server world visible. Because there are literally thousands of different home router models worldwide we are not going to guide you on how to do this. Instead visit www.portforward.com to find a set of instructions specific to your router. You will also need administrative permission on your router in order to make this adjustment, so if it isn't yours ask for permission first.
Our server application only uses the following transport ports. You can amend these using the corresponding command line parameter.
| Port | Protocol | Parameter | Description |
|---|---|---|---|
| 27015 | UDP | -port | Game & content transfers traffic, remote console (RCON) traffic |
| 27015 | TCP | -port | Remote console (RCON) traffic (legacy, no longer necessary) |
| 26900 | UDP | -sport | Valve anti-cheat (VAC) service traffic (auto-increments from default if taken to the next available port) |
You can test the UDP connectivity of your game server here: https://r4to0.azurewebsites.net/checker/