11 Basic Telnet Guide

Telnet is the main Internet protocol for creating a connection with a remote machine. It gives the user the opportunity to be on one computer system and do work on another, which may be across the street or thousands of miles away. Where modems are limited, in the majority, by the quality of telephone lines and a single connection, telnet provides a connection that's error-free and nearly always faster than the latest conventional modems.

11.1 Using Telnet

As with FTP, the actual command for negotiating a telnet connection varies from system to system. The most common is telnet itself, though. It takes the form of:

telnet somewhere.domain

To be safe, we'll use your local system as a working example. By now, you hopefully know your site's domain name. If not, ask or try to figure it out. You'll not get by without it. To open the connection, type:

telnet your.system.name

If the system were wubba.cs.widener.edu, for example, the command would look like:

telnet src.doc.ic.ac.uk

The system will respond with something similar to

Trying 147.31.254.999...
Connected to src.doc.ic.ac.uk
Escape character is '^]'.

The escape character, in this example ^] (Control-]), is the character that will let you go back to the local system to close the connection, suspend it, etc. To close this connection, the user would type ^], and respond to the telnet> prompt with the command close. Local documentation should be checked for information on specific commands, functions, and escape character that can be used.

11.2 Telnet Ports

Many telnet clients also include a third option, the port on which the connection should take place. Normally, port 23 is the default telnet port; the user never has to think about it. But sometimes it's desirable to telnet to a different port on a system, where there may be a service available, or to aid in debugging a problem. Using

telnet somewhere.domain port

will connect the user to the given port on the system somewhere.domain. Many libraries use this port method to offer their facilities to the general Internet community; other services are also available. For instance, one would type

telnet sdps.demon.co.uk 666

Will allow you to port into your POP3 server (if you were connected to Demon Internet and find information about stored mails etc.

11.3 What Can You Do With Telnet?

Telnet allows you to:

• Remotely "log into" an external computer with username and password in order to gain access to files, contents etc.

• Manipulate and maintain your web pages (delete files, create directories etc).

• Play online games across the Internet

• Access server information - status reports etc

Go to the previous, next, chapter, table of contents.