I have this issue that especially on a Mac when I close a Node server "CTRL + Z" the server gets killed but the ports don't get released.
What is the proper way to close a server to make sure that the ports get closed so I can restart the server on the same port?
They key combination to kill a server (or any process in bash) is CTRL+C. CTRL+Z merely stops (pauses) the process and returns you to the current shell and can be resumed using fg.