Telnet

1. What is Telnet?

Telnet is a protocol or language which is used for communication between two or more computers and other machines on a network. The author of this article says it is ancient, he specifies in Internet terms; the protocol dates back to 1973. Well I’m sorry, 1973 is not that ancient to me!

Telnet is defined as: a network protocol used on the Internet or local area networks to provide a bidirectional interactive text-oriented communications facility using a virtual terminal connection.

And it breaks down to the following:

• Network protocol: That’s basically a language, a way for machines to talk to one another.

• Bidirectional: That means Telnet is not one-way; it can be used to send and receive information.

• Interactive: That means Telnet basically expects a live user on one end of the line. Telnet is not usually used for computers to talk autonomously with each other, but was built from the ground up to be human-readable.

• Text-oriented: Telnet is a text-only protocol; you won’t see graphics or fancy images while working with Telnet, nor will you be able to transfer files with Telnet.

• Virtual terminal: Historically, a terminal was a “dumb” computer, with only a keyboard and a screen and no powerful built-in processing facilities. Modern computers can take on the role of a terminal (i.e, open a communications session with another computer), but they are not “real” terminals (their hardware is more powerful). Thus, they are virtual terminals.

The above information taken from - What Is Telnet & What Are Its Uses? [MakeUseOf Explains]. (n.d.). Retrieved April 27, 2016, from http://www.makeuseof.com/tag/telnet-makeuseof-explains/

2. How is it used?

Telnet is a terminal emulation protocol, which means one can log into another computer and view the remote computer in a window they are on. This allows file management from the remote system, however, it is not a secure connection. The data is transferred in plaintext, there is no encryption, which simply means anybody snooping on your network can use this information to hack into the machines.

The Telnet protocol has to be activated on the computer. I found the switch in the Programs section of Control Panel under Turn Windows features on and off. My attempt to experiment with Telnet failed because I don’t have my computer set to allow remote control. This is for obvious reasons. Mainly security.

3. What type of information can a technician gain from using Telnet?

A. Telnet to port 25 on a computer that runs Simple Mail Transfer Protocol (SMTP) services to troubleshoot SMTP communication problems.

B. Telnet to POP (Post Office Protocol) server to check if the mail server is accepting connections.

C. Telnet to IMAP (Internet Message Access Protocol) if you are experiencing connectivity problems.

D. Harry Hacker can look for open ports to try to hack into an unsuspecting computer.

It is claimed that using Telnet is a useful troubleshooting device if one knows the protocol. I suggest not using it and exchanging it for a more secure protocol such as SSH. Why open yourself for trouble when your first intention was to “troubleshoot”?

Well, that’s about all for now, have fun with whatever you do, and “Happy Researching”.