Definition of Telnet
For some people may have never heard of this term, a technology on a network commonly referred to as Telnet. The definition of Telnet or Telecommunication Network is a client-server protocol that can provide access to computers remotely (Remote).
This Telnet device is commonly abbreviated as TN and can also be interpreted as a virtual or terminal emulation that utilizes the protocol with the intended purpose the same, namely accessing computers remotely.
In addition to logging in or accessing other computers Telnet is also commonly used to access various public services such as catalogs, libraries or other types of databases. In other words, we can connect and access between computers while on a network. This is believed to be easier than giving applications to all users who want to access.
Indeed, there are currently many emerging softwares Remote such as Team Viewer and others. But still for its use requires an internet connection and because it has a special function for Remote from a longer distance Team Viewer also requires the target computer ID and Password. In Telnet the use is more or less the same but without involving external software (using Command Line on a computer) and the distance is smaller.
History of Telnet
Given its inherent role in the use of computers, the history of the emergence of Telnet (Telecommunication Network) is not much at odds with the popularity of the use of the computer itself. This Telnet protocol was first introduced to the public by someone named Postel in 1980.
Because of its emergence many developers began designing software similar to Telnet but with different capacities and capabilities – different . However, the existence of Telnet still has its own place for users.
Although currently not as popular as the Internet, the existence of Telnet has become part of the Internet and the computer world since the advent of the idea of connecting computers through a network.
But for forms and innovations have undergone many changes over time. As with most of the weak points of the Internet, on Telnet also still found deficiencies that are prone to hacking or burglary. Therefore need better protection on the computer involved.
For the function of Telnet itself was briefly mentioned earlier namely to be able to access computers remotely or the term is Remote. This is because when using Telnet the computer will be able to function as a terminal from other computers on the internet network. By using Telnet, users can also log into other computers and carry out activities on the computer as if they were used directly.
In Telnet the user interface is quite friendly and simple so that the operation does not require a long time in understanding. As a user you only need to give remote commands as well as do the same thing to the Command Line of your own computer.
However, please note that in this Telnet the use of NTLM Authentication is not encrypted so as previously explained be prone to being hacked by sniffers to steal their passwords. The System Administrator should avoid using Telnet Server, but SSH on Linux to prevent password data theft.
To be able to use Telnet also need to remember that there are a number of conditions that must be met, starting with remote computer devices and remote conditions. connected (LAN or Wireless). In addition, the computer must also be connected to port 23 or SSH 22. After all the requirements have been met then can install Telnet.
How it Works Telnet
Before discussing about how Telnet works, we first know that Telnet uses 2 programs namely Client and Server. The process of working with Telnet will always involve these two programs. For each task of the Client and Server are as follows:
- Making a TCP connection or Transfer Control Protocol with the server
- Receiving data input or commands from the user (19659023) Data input entry will be reformatted first and changed in standard format before being sent to the server
- Receiving output from the server
- Providing information on network software regarding the readiness of the computer to accept connections
- Receiving input or request in standard form from the client
- Execute commands that have been entered
- Sending output or results to the client for further action by the user
After understanding each task on the Client and Server then there should be an overview of the ways Telnet work as a whole. Users or users on the client first prepare a TCP connection and type the name (ID) and password so that they can be connected to the server.
After verification and proven that the ID and password are entered correctly then the server will provide information to the network software that all parties are ready and connected.
The software will bring up a shell prompt as a place to write commands to run. After being filled in by the user, the command will be changed into standard format and then can be sent to the server . The server receives the command and executes it and provides output to the user through the client terminal. Thus the user or user can read from the screen whether the command that was executed was successful or not.
That is an explanation of the meaning of telnet and its function and how it works. Hopefully useful and easy to understand!