telnet IP prot
E.g:
telnet 192.168.60.128 8080
The meaning is that I want to test whether some hosts whose IP is 192.168.60.128 and whose port number is 8080 are open and have permission to access 192.168.60.128 .
It is worth noting that telnet packets are transmitted in clear text.
ip + interface can be accessed, a box will pop up as shown in success.png; if there is an access error, there will be a prompt, as shown in error.png
