Fix “FAILED TO BIND TO PORT” on a Minecraft server

This error means the server tried to open its port and could not. Either another program already uses that port, or the address in server.properties is not one your machine has. The server shuts down, and the fix is quick once you know which case you have.

By the Nodewave team · Updated 8 November 2026

What the message says

The log shows lines like these:

**** FAILED TO BIND TO PORT!
The exception was: java.net.BindException: Address already in use
Perhaps a server is already running on that port?

“Address already in use” means a port conflict. “Cannot assign requested address” means the server-ip setting is not an address of this machine.

1. Is another server already running?

The most common cause is a copy of the server that never stopped: a closed window, a crash, a background screen or tmux session, or a service that restarted it. Find what holds the port. On Linux:

sudo ss -tlnp | grep 25565

On Windows:

netstat -ano | findstr :25565

The last column on Windows is the process ID, which you can look up in Task Manager. On Linux, the process is named in the output. If it is your old server, stop it properly, with stop in its console or systemctl stop for a service, and start the new one. If it keeps coming back, check screen -ls, tmux ls and your service list.

2. Leave server-ip empty

In server.properties, server-ip should normally be empty, so the server listens on every address:

server-ip=

If you enter an IP that is not on one of the machine's network interfaces, the server fails with this error. That includes a public IP that your host maps to the machine without assigning it to the server itself.

3. Give each server its own port

Two servers on one machine cannot share a port. Change server-port in the second server's server.properties, for example to 25566. Players then join with address:25566, or you can add an SRV record so they can leave the port out; see how to fix join errors.

4. Use a port above 1024

On Linux, only root can open ports below 1024. Stay with 25565 or another high port rather than running the server as root.

5. Game panels and proxies

A game panel gives every server its own port. Leave server-port alone and use the port the panel assigns, because the panel can overwrite your edits at start. On a Velocity or BungeeCord network, the proxy takes the public port, usually 25565, and each game server behind it needs its own port.

6. Restarts that fail now and then

If a scheduled restart sometimes fails with this error, the old process had not released the port yet. Make your restart script wait until the old process has exited, then pause a few seconds before it starts the new one.

Check that it works

After the server says “Done”, test the port from another machine:

nc -vz your-server-ip 25565

If players still can't join, check the firewall as described in the join error guide.