Server side
Use netcat on Linux as server: nc -lkC 192.168.71.102 5555.
Here -l means listen; -k means not close when client closed.
-C means Send CRLF as line-ending, which is very useful when connect with telnet from Windows.
If the client is netcat, -C is unnecessary.
Client side
Use MobaXterm netcat
Run nc 192.168.71.102 5555 in MobaXterm. Press Ctrl-c to quit connection session.
Use telnet on Windows
telnet 192.168.71.102 5555.
Open local echo: press Ctrl+] to open telnet prompt,
then input set localecho and press <Enter> only to leave telnet prompt environment.
Press q in telnet prompt environment to quit telnet session.