Basic answer: What is Telnet?

With the development of the network, more application settings have been gradually popularized, and we are not simply using some specific protocols to complete the work. It is like Telnet, because it is gradually used, and many people do not know what it is. Next we will introduce this classic remote logon protocol.

What is Telnet and remote logon?

In the past, few people could afford computers, let alone powerful computers. So at that time, people used Telnet to access the Internet: that is, they connected their low-performance computers to large computers with good remote performance. Once they were connected, their computer is like a terminal on these remote computers, and they are like sitting in front of the screen of the remote mainframe and entering commands to run programs on the large machine. People call this method of connecting their computers to a remote computer as "login", and call this login technology Telnet remote login ).

Telnet refers to the Internet remote logon protocol. It allows you to log on to another remote computer over the Internet in front of your computer. This computer can be in the next room, it can also be at the other end of the earth. After you log on to the remote computer, your computer is like a terminal of the remote computer, you can use your computer to directly manipulate the remote computer, enjoy the same power as the local terminal of the remote computer. You can start an interactive program on a remote computer to retrieve a database from a remote computer, and use the powerful computing capability of the remote computer to solve a certain equation.

But now Telnet is used less and less. There are three main reasons:

First, the performance of personal computers is getting stronger and stronger, which gradually weakens the requirements for running programs on other computers.

Second, the Telnet server is not secure because it allows others to access its operating system and files.

Third, Telnet is not easy to use, especially for beginners.

However, Telnet still has many advantages. For example, if your computer lacks some functions, you can use Telnet to connect to a remote computer and use the functions on the remote computer to complete your work, in this case, all services provided on the Internet can be used through Telnet.

However, the main purpose of Telnet is to use the information resources on the remote computer. If your main purpose is to transfer files between the local computer and the remote computer, FTP is much more effective.

How Telnet works

What is Telnet? We have already explained this for you. Now we will explain some of its working principles. When you use Telnet to log on to the remote computer system, you actually start two programs, one called the Telnet client program, which runs on your local machine and the other is the Telnet server program, it runs on the remote computer you want to log on to. The customer program on the local machine must complete the following functions:

1) Establish a TCP connection with the server.

2) receive the characters you entered from the keyboard.

3) convert the string you entered into a standard format and send it to the remote server.

4) receive output information from the remote server.

5) display the information on your screen.

A remote computer's "service" program is usually called a "Genie". It waits quietly on a remote computer. Upon receiving your request, it becomes active immediately and completes the following functions:

1) inform your computer that the remote computer is ready.

2) Wait for you to enter the command.

3) respond to your commands, such as displaying directory content or executing a program ).

4) Send the execution result back to your computer.

5) Wait for your command again.

In the Internet, many services adopt such a Client/Server structure. For Internet users, it is usually enough to understand the client program.

Remote login using Windows95

What is Telnet and how it works, we have already understood it. Now let's take a look at the specific operations. Here we will introduce WIN95 remote implementation operations. The Telnet client program of Windows 95 is one of the command line programs of Windows 95. When Microsoft TCP/IP is installed, the Telnet client program is automatically installed on the system.

Use the Telnet client program of Windows 95 for remote logon. The procedure is as follows:

(1) connect to the Internet.

(2) Select "run" from the "Start" menu, or select "MS-DOS tip mode" under the "program" menu to convert to the command prompt.

(3) at the command prompt, connect to Telnet using either of the following two methods.

One way is to enter the "telnet" command, space, and the corresponding telnet host address. If the host prompts you to enter a port number, you can add a space after the host address, followed by the corresponding port number. Then, press Enter.

Alternatively, enter the "telnet" command and press enter to open the main Telnet window. In this window, select "remote system" under "connection". If necessary, enter the host name and port number in the dialog box that appears, and then click "Connect.

(4) After the remote host is successfully connected to Telnet, the computer will prompt you to enter the user name and password. If you are connected to a free service system such as BBS, Archie, And Gopher, then, you can enter the remote host system by entering bbs, archie, or gopher as the user name.

In this way, Telnet has set up a bridge for you to connect to a remote host. Now you can act in full accordance with the commands of the remote host.