8.7 TCP/IP Suite: Utilities
8.7.2 How and when to use Telnet to test, validate, 
and troubleshoot IP connectivity
Telnet, which uses port 23, allows users to log into and execute text-based commands when working on a remote server.

To use Telnet, the user needs to run Telnet.exe at the command prompt or from the Start Menu (Start | Programs | Accessories | Telnet. Then selecting Connect | Remote System until a dialog box appears.

In order to connect to a host, the client must be able to resolve the name to an IP address. The user must also specify the port to connect to (Telnet port 23) on the remote server. VT100 is the default terminal emulation used.

If a user is having problems logging onto a server, Telnet may still be functional. In this case, the user can log on using Telnet and administer the problems associated with the server. For example, if a Windows NT server crashes and displays a Blue Screen and the server allows for a remote administration card to be plugged in, the user is able Telnet to this card and can determine the problem of the server and reboot it.