Telnet - A Tutorial to Telnet Now you may be looking at this going, "What the hell is Telnet?". If you are, don't worry, I'll explain everything. First of all, Telnet is software that allows you to connect to another Telnet Host. In windows systems Telnet is usually called Telnet32.exe or Telnet.exe. In newer versions of windows it is Telnet32.exe. *** Note to Windows XP users: Don't go and get the old version of Telnet, because you have a DOS-Based one. I'll give commands along this guide so you can enjoy it too. You have to either run "Telnet" or "cmd" and then "Telnet". Telnet is not illegal and is used by thousands of remote computers to interchange data, share connections, and do many other things that would be impossible without it. The default port for Telnet is port 23. When I say for instance, 'Connect to the sys' I am referring to connecting on the system's default port for Telnet. Sometimes you can't determine a port so you will have to port scan a sys to find the Telnet Ports. Port 25 is the 'Sendmail Protocol' port. We will be dealing with this port as well.