Game Server Running but Clients Can’t Connect

[Juniper]

Hello

 

I’ve set up my game server using Intersect Engine, and it runs fine on my local machine. However, when I try to connect from another device, it either times out or fails to establish a connection. I’ve double-checked that the server is running, and I can connect using localhost, but external connections don’t seem to work.

 

I’ve already tried port forwarding on my router, ensuring that the correct ports are open. I also disabled my firewall temporarily to see if that was the issue, but I still can’t get clients to connect. I suspect it could be a networking configuration issue or something specific to how Intersect handles connections. Could it be related to my ISP blocking certain ports, or do I need to adjust something in the server settings? Checked https://answers.microsoft.com/en-us/xbox/forum/all/cannot-connect-to-certain-game-servers/223bf30c-48bc-4411-a0ae-c478b24bd0cb-Salesforce Administrator guide related to this and found it quite informative.

 

 

 

Has anyone else run into this problem? Are there specific troubleshooting steps I should follow to ensure my server is properly accessible from outside my local network? Any help would be greatly appreciated!

 

 

 

 

Thank you!!

[Ainz Ooal Gown]

Hi,

 

Have you had a look through the official documentation for deployment?

 

https://docs.freemmorpgmaker.com/en-US/deploy/forwarding/

 

Also this might be helpful:

1. Double Check Port Forwarding
   1. Intersect Engine uses port 5400 by default (TCP).
   2. In your router settings:
      1. Make sure you're forwarding TCP port 5400 to your local IP address (like 192.168.x.x).
      2. Double-check the internal and external port numbers match.
      3. Make sure the local IP hasn't changed (set a static IP or DHCP reservation for your host machine).
2. Firewall + Antivirus
   1. Temporarily disabling the firewall was a good test, but also check if antivirus software might have its own network protection.
   2. If your firewall is back on, make sure there's an inbound rule allowing TCP on port 5400.
3. Test Using External IP
   1. Is the second device you are testing within the same network, or external to your network?
   2. Have a friend (or yourself using mobile data/tether) try connecting with your public IP address. You can find this at whatismyip.com.
   3. Example: if your IP is 123.123.123.123, they should enter that in the Intersect client.
4. Check Intersect Server Config
   1. Open your resources/config.json on the server.
   2. Make sure port is correct “5400” or whatever you are using.
   3. Also verify the client configuration (client's resources/config.xml) points to your public IP (not localhost).
5. ISP NAT or CGNAT
   1. Some ISPs use Carrier-Grade NAT (CGNAT), which blocks inbound connections.
   2. You can check if you’re behind CGNAT by comparing your router’s WAN IP with your public IP from whatismyip.com.
      1. If they're different, you might be under CGNAT, and port forwarding won’t work.
      2. In this case, you’d need to:
         1. Contact your ISP for a public/static IP.
         2. Or use a VPN with port forwarding like ZeroTier, Tailscale, or a VPS.
6. UPnP and Router Reboot
   1. If your router supports UPnP, try enabling it or disable it if it’s causing issues.
   2. Always reboot the router after making port forwarding changes to ensure they apply.
7. Server Logging / Debug
   1. Check Intersect’s server logs to see if it even registers the connection attempt from the outside device.
   2. If there’s no attempt at all, it means the request isn’t reaching your PC—pointing to a router or ISP block.

 

Also I tend to do all my development locally on my machine and use Intersects Hosting for my deployed server:

 

 

Hope this helps