Telnet (teletype network) is a network protocol used on the Internet or local area networks to provide a bidirectional interactive communications facility. Typically, telnet provides access to a command-line interface on a remote host via a virtual terminal connection which consists of an 8-bit byte oriented data connection over the Transmission Control Protocol (TCP).

Configuration: Telnet is a xinetd based services.

HOW TO CONFIGURE TELNET IN LINUX SYSTEM

You can use yum installation or rpm installation process to install the telnet software.

To check Telnet is already installed on your system or not use the following command.

rpm -qa|grep telnet

For Yum installation use the following command

yum install telnet-server

For rpm installation use the following command

rpm -ivh telnet-server.x.x.rpm (x means the version of software)

The above command will install telnet

Then to activate the Telnet Server

Edit the file /etc/xinetd.d/telnet or /etc/xinetd.d/krb5-telnet

changing the two lines to:

# default: on

disabled = no

Then restart the xinetd service by the following commands

1. /etc/rc.d/init.d/xinetd restart

or

2. service xinetd restart

Now U can login to any user mentioned in the remote machine except the root using the following command.

telnet 10.201.4.109

login : sandip

password: xxxxxxx

Telnet doesn't give direct access to root so to login to the root now type

su root

password: xxxxxxx

But in the above case u will not get the full root environment i.e. you can’t run all commands, so to get full root environment type the following command.

su -

The above command will set full root environment for root user.