Troubleshooting Connection Issues
Common Connection Problems
Most connection issues fall into a few categories: firewall blocking, incorrect IP usage, or timing issues. Let's solve each one.
"Friend Can't Join My Game"
Verify MoleTun Connection
Both players must show as connected in MoleTun with green status. Check that you're in the same room.
Use Correct IP
The host shares their MoleTun IP (shown in the app), NOT their regular IP. It typically starts with 10.x.x.x.
Start Game After MoleTun
Launch MoleTun and connect to the room BEFORE starting the game. Some games cache network state at launch.
Host Opens Game First
The host should have their server running before friends attempt to connect.
Firewall Issues
Windows Firewall
- •Open Windows Security → Firewall & network protection
- •Click "Allow an app through firewall"
- •Ensure both the game AND MoleTun have Private and Public checked
- •If not listed, click "Allow another app" to add them
Antivirus Software
Some antivirus programs block virtual network adapters. Temporarily disable real-time protection to test, then add MoleTun to exceptions if that fixes it.
Router Firewall
Most home routers don't block outbound connections, but corporate or heavily configured networks might. MoleTun uses UDP ports 4242-4243 by default.
"Connection Timeout" Errors
This usually means packets aren't reaching the host:
- •Check host's firewall: Ensure game port is open (game-specific)
- •Restart MoleTun: Sometimes connections need a fresh handshake
- •Try host swap: Have a different player host—their network might have better connectivity
"Peer Not Found"
If you can't see other room members:
- •Re-enter room code: Leave and rejoin the MoleTun room
- •Check internet: Ensure both players have active internet
- •Restart app: Close and reopen MoleTun
- •Create new room: Occasionally rooms can get stuck—create a fresh one
Game-Specific Troubleshooting
Minecraft
- •Use the MoleTun IP with port 25565:
10.x.x.x:25565 - •"Open to LAN" must be clicked after loading the world
- •Check that you're on the same Minecraft version
Valheim
- •Default port is 2456
- •Host must be in-game (not just at menu)
- •Character must be loaded into the world
Terraria
- •Host via "Host & Play" not "Play"
- •Port 7777 is default
- •Password must match if set
The most common issue is using the wrong IP. Always use the IP shown in MoleTun (10.x.x.x range), not your regular internet IP or 192.168.x.x local IP.
Still Not Working?
Do all players need MoleTun installed?▼
Yes. MoleTun creates a virtual network that all participants must be connected to. Everyone needs the app running and connected to the same room.
Can I use MoleTun with other networking tools?▼
Not recommended. Running multiple networking tools causes routing conflicts. Disable other virtual network software when using MoleTun.
Why does it work sometimes but not others?▼
Inconsistent connections usually indicate ISP issues, unstable WiFi, or firewall software that re-enables itself. Check these first.
How do I check if MoleTun is connected properly?▼
In the MoleTun app, your status should show green and you should see other room members listed. You can also ping other members' IPs from command prompt.