Telnet

Telnet is a terminal emulation application designed to allow remote access to machines running the telnetd daemon.

In recent years the use of telnet has dramatically reduced with the introduction of the far more secure ssh.

Note that while telnetd is rarely if ever used anymore, the telnet client itself is still extremely useful for troubleshooting many server applications; for example, one may use telnet to interact directly with SMTP, HTTP, IMAP, or POP3 daemons to allow more effective troubleshooting. (See the mail toaster article for examples.)

Common flags

-l <username> -- used to specify the username to use when logging into the remote machine.
-n <filename> -- used to create a trace file of the telnet session.

Example usage

[light@splat ~]$ telnet insecure.host.com
Trying 10.0.0.1...
Connected to insecure.host.com.
Escape character is '^]'.
Password:
[light@insecure ~]$ logout
Connection closed by foreign host.