Port Already in Use

Troubleshoot port conflicts with Exposr.

Public port unavailable

If the default port 25565 is taken by another agent, Exposr automatically falls back to a random port in the 20000–30000 range. If you specified a custom port and it's unavailable, Exposr will not fall back.

How to fix:

• Let Exposr use automatic port assignment (omit the to parameter)
• Choose a different public port: exposr expose 3000 to 28000

Local port not listening

If the local service isn't running on the specified port, Exposr will connect to the server but forwarded traffic will fail.

How to diagnose:

# Check if the local port is listening
netstat -an | findstr :3000    # Windows
ss -tlnp | grep :3000          # Linux

Server ports in use

If the server's control (9000) or data (9001) ports are already in use by another process, the server will fail to start.

How to diagnose:

ss -tlnp | grep -E '9000|9001'