Installing Telnet

Telnet is a lesser used tool for troubleshooting. It is not installed in Windows systems by default because of security risks, but it can be added. Attackers often use Telnet to check for open ports on a system that has Telnet enabled, so it is more secure to keep Telnet disabled unless it's needed.

When Telnet is installed on client and server computers, you can connect a Telnet client to a Telnet server. It provides a command-line interface that allows you to run Telnet commands from the Telnet client that are executed on the Telnet server. Commands include command-line programs, shell commands, and scripts.

One of the risks with Telnet is that commands go across the network in clear text. An attacker with a sniffer can capture the traffic and easily read it.

Many programs that use Telnet can be configured to encrypt the traffic with Secure Shell (SSH). The ensures that attackers are not able read the traffic. You can use the following steps to install both the Telnet client and the Telnet server on a Windows Server 2008 server:

Telnet presents significant risks to computers in a network. You should not install Telnet on a computer in a production environment unless it's actually needed.

• Click Start → Administrative Tools → Server Manager.
• Select Features. Click Add Features.
• Scroll down, and select Telnet Client and Telnet Server. Click Next.
• Click Install. When the installation is complete, click Close.

At this point, Telnet is installed. If you enter telnet /? at the command prompt, it will show the output of a help file. You can start a Telnet session from a Telnet client with the following command:

If you have more interest in Telnet, you can check out Microsoft's Telnet Operations Guide at http://technet.microsoft.com/library/cc753164.aspx.