Telnet is a protocol that lets you connect to other computers on the Internet and use the resources present there. These resources can be online databases, chat services, programs etc.
Each computer connected on the Internet has a unique address that helps to locate it. This is the IP (Internet Protocol) address. The address consists of a set of four numbers separated by periods. Thus, a typical address can be 220.127.116.11. The addresses can also be written in words www.webdevelopersnotes.com, which helps in easy recollection (by humans).
To telnet to a computer, you should know its IP address, username and password. Telnet is available on the Windows PC (XP users see the next paragraph). Click on the ‘Start’ Button and select ‘Run’. Type telnet in the Pop-up window. The Telnet window now opens up. Select ‘Remote system’ from the ‘Connect’ drop down menu. Type in the remote computers’ address. (Note: you have to be connected to the Internet in order to use Telnet). The remote machine will now ask for a username and password. Type these to login. Your local computer now acts as a terminal of the distant machine and you can use its resources including its processor power!
Note: Some telnet services require you to connect only to a specific port on the remote computer. In such cases, you should also know the port number and append it to the IP address.
The Windows XP telnet window is slightly different. You have to click on the ‘Start’ button and then on ‘Run’. Type telnet in the pop-up window. This should now start the telnet window with the prompt Microsoft Telnet>. To connect to a remote computer type, open site-name. To close the window, type quit at the telnet prompt.
Note: The site-name can be the I.P. address of the remote computer, its domain name or the telnet host name.
The telnet program is also built into Unix systems. Just type telnet site-name at the prompt. You can use telnet from Macintosh computer employing a telnet client program.
Telnet is useful not only to retrieve emails, information and run programs but can also play an important part in web site maintenance.
Steve Jobs struck a deal with the venture capital division of Xerox by letting them invest $1 million in exchange for a look at the technologies and devices the company was working on at PARC. Jobs successfully imported the mouse, GUI and other technologies into Apple machines. [more...]