What is Telnet?
Telnet is a protocol used on the internet or local area network(LAN). To provide a bidirectional interactive text-oriented communication facility using a virtual terminal connection. User data is interspersed in-band with Telnet control information in an 8-bit byte oriented data connection over the transmission control protocol(TCP).
- TELNET is a general protocol, meant to support logging in from almost any type of terminal to almost any type of computer.
- It allows a user at one site to establish a TCP connection to a login server or terminal server at another site.
- A TELNET server generally listens on TCP port 23.
- We can also change the listen port.
Disadvantages
Telnet is not a secure protocol When you log into a remote host using Telnet, your username and password are sent “in the clear” – meaning, in plain text and not encrypted in any way. That means your credentials can be (relatively) easily intercepted and used to gain access to that device. For this reason (and many others) Telnet has been largely replaced by the more secure SSH protocol.