First, we run cmd and enter the command netstat -ano to display the status of all port monitors. You can also use the penetration test tool nmap to scan local ports. When we get these port numbers, we need to know the services corresponding to the ports. At this time, we can use the command: netstat -ano | findstr "port number". You can find that the PID corresponding to the local port 20000 is 9496, and then open the task manager to find the corresponding service through PID.

List of various ports and corresponding services:

1 tcpmux TCP port service multiplexing.

5 rje remote operation portal.

7 echo echo service.

9 discard is an empty service for connection testing.

1 1 systat is used to list the system status of the connection ports.

13 daytime sends the date and time to the requesting host.

17 qotd sends daily aphorisms to connected hosts.

18 msp message protocol.

19 chargen character generation service; Endless characters.

20 ftp-data FTP data port.