This post will talk about an application protocol that is utilized on the Internet or local area network (LAN) – Telnet. The content will focus on its definition, working principle, and common uses.

What Is Telnet

Telnet, an application protocol, offers two-way interactive communication compatibility for computers on the Internet and local area networks. It was developed in 1969 and built for managing remote device or server functioning like MSTSC.

The Windows telnet has a command line interface and is well-known as the original protocol since the release of Internet. According to user report, it is complicated to check if a port is opened. Things will be different if you utilize network protocol telnet. It has been proven to be one of the most efficient ways to do that.

Tip: You can use telnet commands in the command-line utility under Windows OS, MacOS, Linux and other Unix-like systems. How does the telnet work? What is telnet used for? To get more details, please keep reading this post of MiniTool.

Further reading:

Due to the appearance of SSH, Telnet becomes less popular. Besides, as telnet Windows 10 was developed very early, it doesn’t have any form of encryption, which cannot fulfill the security requirement of modern users. SSH vs telnet, SSH wins more popularity.

How Does the Telnet Work

Telnet utility enables users to test the connectivity of remote machines and issue commands via keyboard. Most people tend to utilize graphical interfaces, but there is no denying that telnet is still one of the easiest methods to examine connectivity of telnet ports.

How does the telnet work exactly? Telnet offers bidirectional interactive text-oriented communication facility via the virtual terminal connection over 8 bytes. Then the user data is interspersed in-band with telnet control information over TCP (Transmission Control Protocol).

In most cases, Telnet is utilized on a terminal to carry out the functions in the distance.

With telnet protocol, users can connect to the server. It means that you can enter a command prompt by following the path: telnet hostname port. After that, users can execute the commands on the server with specific telnet commands in the telnet prompt. If users want to end a session or log off, just type telnet commands end with telnet.

How to Enable Telnet

What is telnet used for? After reading the above content, you can know that telnet is frequently used to test or troubleshoot distant web or mail servers, check telnet port, as well as to access to MUDs (multi-user dungeon games) remotely.

To use telnet, you need to enable telnet client in your operating system. If you are using Microsoft Windows operating system, you can refer to the following steps to enable the telnet client.

Tip: You should note that Telnet will be disable by default in Windows settings. If you would like to use it, turn on it first. Otherwise, you will receive the error message like this: ‘telnet’ is not recognized as an internal or external command, operable program or C:\>

Top recommendation: Python Is Not Recognized as Internal or External Command [Fixed]

The Command Prompt enables you to open telnet as well besides Settings.

Step 1: Run Command Prompt as administrator from the search box.

  1. Type cmd in the search box.
  2. Right click on Command Prompt from the search results and choose the Run as administrator from the pop-up menu.

run command prompt as administrator from the search box

Step 2: In the next window, type the following command and hit Enter to execute it. After that, the telnet will be ready for checking your ports.

Dism /Online /Enable-feature /FeatureName:TelnetClient

Note: You can get the same result by typing the command below and hit Enter in the PowerShell prompt: Install-WindowsFeature -name Telnet-Client

To check if the port is opened or not, you can continue the following steps.

Step 3: After enabling the telnet with Command Prompt or PowerShell, type the command line below in the prompt and hit Enter.

Tip: Replace the domain name or ip and port with the exact one. In addition, you don’t have to add the bracket. For instance, if the domain name is and the port is 25, you should type: telnet 25.

telnet [domain name or ip] [port]

Then, if the port is opened, you will get a blank screen. On the contrary, you will receive an error message.

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