How Does Telnet Work?

January 7, 2005

Use these to jump around or read it all…

[Telnet]
[Where Will I Find Telnet?]
[How Does It Work?]

Ever since I put up the three CGI tutorials I have been getting mail asking what I mean by “telnet into your system.” I put this quick lesson together to explain in a bit more detail.

Telnet

The term “telnet” is a mashing together of “telephone” and “network.” The term means to use telephone lines for the purpose of contacting and entering
another network computer. For example, let’s say I am on joe.net and there is a file I want on fred.com. I would use the telnet program to attach from my server to the other.

Please note: Just because I am discussing telnet does not mean you are guaranteed telnet capabilities with your account. You may not be able to connect you own system. It’s up to the server people whether to allow you access or not.

Even if you can connect, you still may not be able to do all the things I talk about in the CGI tutorials. Again, it’s up to your server people to give you the ability to do anything. Hopefully you will have full access, but if not, contact the people you pay each month and see if your account can be altered to include
full access.

Where Will I Find Telnet?

If you are running Windows 95 or Windows 3.x, then you already have it on your system. Windows 95 users will find the program by clicking on Start, then Programs, then Accessories, and then choose Telnet. The icon will look like the one in the heading text. You could
also jump right to it by clicking on Start, choose Run, and type in Telnet. The program will pop right up.

If you have Windows 3.x, then you’ll still find it under the Accessories icon, but it will be named Terminal.

Those of you using MAC systems will need to grab a telnet program. Telnet programs are plentiful and small. You’ll have no trouble finding one. See https://www.shareware.com or Yahoo’s Telnet Page. Telnet programs are usually very small. All they do is make the connection. The two connected servers do the rest.

How Does It Work?

Well, now I’m into an area that isn’t so exact. The programs will all work just about the same way, so I’m going to talk in generalities here. I’ll use
screen captures of my Windows 95 telnet program to explain.

First off, you have to attach to your server just like you do when you want to surf or get your e-mail. After clicking on the Telnet or Terminal icon to start the program, you’ll get some kind of blank screen where text commands will appear. Mine looks like this:

Somewhere along the top of the screen will be a series of menu items. One of them should give you the ability to connect. Your connection command
might be under one of the menus. It will be fairly obvious when you run across it. Sometimes it says “Connect to Another System” or words to that effect. My connect command is right along the top. It looks like this:

After clicking on connect, you’ll be given a way to enter the name of the machine you want to attach to. Usually you’ll be good to go by entering
the Web address without the https://. I can get away with just putting in the domain name. You may also be asked for a port and a terminal type. The settings below are the most common. Usually they are chosen for you.

Putting in just the domain will get you to the front door of the server. If you are given a longer address including some directories, put them right
in where you enter where you want to attach. They will get you right to where you want to go. Click on Connect or hit Enter to initiate the connection.

Magic happens and hopefully a connection will be made. You’ll know it happened when the screen comes alive and asks for a login and password. Put in the correct pair and you’re good to go. My telnet looks like this: