Windows Sockets applications generally use the gethostbyname() function to resolve a host name to an IP address. The gethostbyname() function uses the following (default) name look-up sequence: Checks the local host name for a matching name. Checks the hosts file for a matching name entry. If a Domain Name Server is configured, it queries it. If no match is found, try NetBIOS name-resolution until the point at which DNS resolution is attempted. Some applications use the gethostbyaddr() function to resolve an IP address to a host name. The gethostbyaddr() call uses the following (default) sequence: Check the host's file for a matching address entry. If a Domain Name Server is configured, it queries it. Send a NetBIOS Adapter Status Request to the IP address being queried. If it responds with a list of NetBIOS names registered for the adapter, parse it for the computer name.