PortQry exe command line utility - To check TCP/IP Connectivity
Portqry.exe is a command-line utility that you can use to help troubleshoot TCP/IP connectivity issues. Portqry.exe runs on Windows 2000-based computers, on Windows XP-based computers, and on Windows Server 2003-based computers. The utility reports the port status of TCP and UDP ports on a computer that you select. It can be downloaded from here, http://ss64.com/nt/portqry.html