Telnet is a protocol designed to remotely access computers in a client-server fashion. Telnet is inherently insecure, as the data passed from the client to the server or vice-versa is not encrypted. For connections through insecure networks (such as the Internet), SSH (Secured SHell), should be used so all communications between the client and server are encrypted.
Examples[edit | edit source]
Test if the HTTP port is open and its service listening[edit | edit source]
telnet localhost 80
Send an email[edit | edit source]
telnet localhost 25 Trying 127.0.0.1... Connected to localhost.localdomain. Escape character is '^]'. 220 smtp.mydomain.com mail from:<email@example.com> 250 2.1.0 <firstname.lastname@example.org>... Sender ok rcpt to:<email@example.com> 250 2.1.5 <firstname.lastname@example.org>... Recipient ok data 354 Enter mail, end with "." on a line by itself Let's meet . 250 2.0.0 n514OvkN019941 Message accepted for delivery quit 221 2.0.0 smtp.mydomain.com closing connection Connection closed by foreign host.