What can we do with telnet?

Question

I would like to know everything that can be done with telnet, I am currently using it to determine if a remote computer is listening on a specific port like telnet [machine] [port]. any ideas please

Answer 1

Look at telnet, how basically opening a socket on another machine on a port.

You can log in to another computer (not securely) using it. If you know the SMTP protocol, you can send him an email. If you know how to formulate an HTTP request, you can even make HTTP requests with it and return an HTTP response stream. This is a great tool.

Answer 2

This can be useful when debugging many application level protocols. For instance:

% telnet stackoverflow.com http HEAD / HTTP/1.1 Host: stackoverflow.com 

returns the HTTP headers on the first page of stackoverflow.com.

Although netcat ( man 1 nc ) is more versatile in such tasks.

Answer 3

FTP, HTTP I've already tried. You can use telnet for the web server to work with the headers themselves, etc.

Answer 4

You can interact with the SMTP server to send mail:

 telnet somemailserver.somedomain.com 25 HELO somesender.somesenddomain.com MAIL FROM: [e-mail] RECPT TO: [e-mail] DATA Type message now. . 

Answer 5

You can connect to your mail server and send an email using telnet.

Telnet for hostname on port 25
HELO your_domain_name or whatever MAIL FROM: [e-mail] RCPT TO: them@someplace _else.com

DATA

press ENTER QUIT