Before writing our first network program, let’s discuss a great debugging tool for network programming that you already have—namely, telnet. Telnet is pre-installed on most systems. You should be able to launch it by typing
telnet from a command shell.
In Windows Vista, telnet is installed but deactivated by default. To activate it, go to the Control Panel, select Programs, click “Turn Windows Features On or Off”, and select the “Telnet client” checkbox. The Windows firewall also blocks quite a few network ports that we use in this chapter; you might need an administrator account to unblock them.
You may have ...