Microsoft’s PortQry Utility
Several years ago, Microsoft released a small utility to query for open network ports. The portqry application can be found at http://www.microsoft.com/download/en/details.aspx?id=17148. A KB article describing the application can be found at http://support.microsoft.com/default.aspx?scid=kb;en-us;310099.
Below are some examples of using the utility. The –n parameter is for the IP address or DNS host name. The –e parameter is for the destination port to query for on the remote host.
TCP is the default protocol. The –p parameter can specify TCP, UDP, or BOTH.
The –o parameter allows multiple port values to be queried.
The –r parameter allows a range of port values to be queried.