Your GameServer is out of date
Check that your server is running on the latest Northstar release as it can sometimes include breaking changes.
MasterServer is down
Check Northstar's Discord for annoucements.
Ports are not the same
Your gameserver is configured to listen to a given UDP port.
Masterserver needs to be able to contact your gameserver though that same port (i.e., you can't forward a different external port).
Another Northstar Server is using the port
Shutdown every other server to narrow down the problem
This won't generally help but will allow you to avoid checking for the wrong server.
Check if your server is reachable from your internal network's IP (often starts with
Firewall is blocking ports
In some cases your Firewall or antivirus can prevent your ports to be exposed to your local network. To fix this issue, make a rule to allow your server to listen on your network. Disabling the firewall and antivirus can also work, even if it's not recommended.
Router configuration is incorrect
If your port can be accessed from your local IP but not from your public IP, then it's very likely that your NAT rules aren't properly configured.
Another program is using the port
Sometimes another program listens to the same port as Northstar.
You can check if that's the case by running
netstat -a -busing CMD as admin
As two programs cannot listen to the same port and IP at the same time, changing the listen port can sometimes solve the problem.
Server is using the wrong port
If you are running multiple instances, the other instances may use a higher port number automatically.
You can use
netstat -a -busing CMD as admin to check which process listens on which port.
The TL;DR is that basically when you connect via serverbrowser to your own dedicated gameserver located on the same network, the message goes to your router where it sees that the gameserver IP requested is the same as its IP address. A router that supports NAT loopback will still check forwarding rules, notice that it goes to your server and "turn the packet around" to your server. A router that doesn't support NAT loopback will simply drop the packet, meaning the request to join will never reach your gameserver.
To work around this you can set
ns_auth_allow_insecure 1on the gameserver in the
autoexec_ns_server.cfg. This way you can directly connect to your server via
connect <local gameserver ip>:<port>(e.g.
Note that this still won't allow you to join your server via serverbrowser. You will always have to use the
connectcommand to join it. Also, setting
ns_auth_allow_insecure 1means that anyone that knows the server IP can join it without authenticating with masterserver, meaning that they can impersonate any player on your server. To resolve this you will have to invest into a router that supports NAT loopback or host your gameserver outside your local network.