The telnet command is used to communicate with another host using the TELNET protocol. The telnet programm you know from other systems connect to port 23 of the remote host. Other useful ports are:
- 25 SMTP (simple mail transport protocol)
- 79 finger
- 80 WWW (world wide web)
- 110 POP3 (post office protocol)
The IPaddrss must be known in digits!