Copyright Goodheart-Willcox Co., Inc. Chapter 8 Overview of Network Security and Network Threats 279 Telnet Telnet is a component of the TCP/IP protocol suite that allows a person to remotely log in to another host on the network. Telnet is short for terminal net- work. It is a text-based interface that uses port 23 and allows for remote confi gura- tion and management. When using Telnet, you log in to the remote server or host. Then, you can use the system as if you are directly attached. Telnet has been around for quite some time. However, it is seldom used today. It has security vulnerabilities. One of the biggest issues is the fact that nothing is encrypted during transfer. Windows operating systems still support Telnet, but it is not enabled by default. SSH If you need a terminal-emulation program, it is better to use secure shell. Secure shell (SSH) is an encrypted interface that uses port 22 for transactions. SSH was developed with security in mind. It uses a public key encryption to authenti- cate the source of the data. Another aspect of SSH that is a helpful security feature is secure copy. Secure copy protocol (SCP) is based on SSH to allow the secure copying of fi les from the local host to the remote host. Like SSH, it also uses port 22. SCP supports the prin- ciple of confi dentiality due to its encryption and authentication features. SCP is a feature used more often on Linux distributions than on Windows platforms. FYI Quick Look 8.2.4 Exploring the Telnet Interface Telnet is not installed by default on Windows clients anymore. However, it is still available. To use Telnet, it must fi rst be enabled. Since Telnet is a security risk, it is important to uninstall it once you are done using it. 1. Applying what you have learned, display the Windows Control Panel. Then, click Programs and Features. 2. On the left-hand side of the screen, click the Turn Windows features on or off link. The Windows Features dialog box is displayed, as shown. 3. Scroll down, and check the Telnet Client check box. Click the OK button to update the setting. It may take a few seconds for the changes to be applied. Then, close the Windows Features dialog box and the Control Panel. After Telnet is installed, it can be accessed in the Windows Start menu or by using the command prompt. 4. Applying what you have learned, launch the Windows command prompt, and enter telnet. The prompt changes to refl ect that you are in the Telnet interface. Check to install Telnet