1. Check the occupied ports
netstat -ano | findstr ":NN"
2. Status of the port
LISTENING: Indicates that the port is open but not connected
ESTABLISHED: Indicates that the connection is established and is communicating
TIMA_WAIT: Indicates that there has been a visit, but the visit has ended
reference:
<https://www.cnblogs.com/jessezeng/p/5617105.html>