This example shows how to detect and kill a process running on port 500 on Ubuntu machine.

1. Verify that port 500 is occupied on the machine:

netstat -an | grep 500

• -a is for listing active connections
• -n is to disable DNS lookup and only show IP address.

2. Show the ID of the process that uses port 500:

sudo fuser 500/udp

3. Kill the process:

sudo fuser -k 500/udp