Sometimes you need to know what application is using a specific port. Here is the syntax so I can remember how to do it:

sudo netstat -lpn |grep :{PORTNUMBER}

Just replace {PORTNUMBER} with the port in question:

sudo netstat -lpn |grep :3306

When you do that you’ll get an output sort of like this:

tcp        0      0*               LISTEN      880/mysqld