How WINS works

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Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2, Windows Server 2008, Windows Server 2008 R2, Windows Server 8 Beta

How WINS works

By default, when a computer running Microsoft® Windows® 2000, Windows XP, or a Windows Server 2003 operating system is configured with WINS server addresses (either manually or through DHCP) for its name resolution, it uses hybrid node (h-node) as its node type for NetBIOS name registration unless another NetBIOS node type is configured. For NetBIOS name query and resolution, it also uses h-node behavior, but with a few differences.

For NetBIOS name resolution, a WINS client typically performs the following general sequence of steps to resolve a name:

  1. Client checks to see if the name queried is its local NetBIOS computer name, which it owns.

  2. Client checks its local NetBIOS name cache of remote names. Any name resolved for a remote client is placed in this cache where it remains for 10 minutes.

  3. Client forwards the NetBIOS query to its configured primary WINS server. If the primary WINS server fails to answer the query--either because it is not available or because it does not have an entry for the name--the client will try to contact other configured WINS servers in the order they are listed and configured for its use.

  4. Client broadcasts the NetBIOS query to the local subnet.

  5. Client checks the Lmhosts file for a match to the query, if it is configured to use the Lmhosts file.

  6. Client tries the Hosts file and then a DNS server, if it is configured for one.

Notes

  • For a more detailed description of the default NetBIOS name resolution process as it is performed by computers running Windows XP or a Windows Server 2003 operating system, see Resolving names.

  • In general, Windows operating systems support two major methods of performing network name resolution. These are:

    • Host name resolution. This is Windows sockets-based name resolution which implements the gethostbyname () API to search for a host IP address based on a queried host name. This method relies on either a Hosts file or querying DNS to perform resolution of the name.

    • NetBIOS name resolution. This is name resolution that uses the NetBIOS redirector to search for an address based on a queried NetBIOS name. This method relies on either an Lmhosts file or querying WINS to perform resolution of the name.

    WINS clients running Windows 2000, Windows XP, or a Windows Server 2003 operating system are configured by default to first use DNS to resolve names that are longer than 15 characters or that make use of periods (".") within the name. For names that are less than 15 characters and do not use periods, DNS is also used again as a final option after a WINS query fails if the client is configured to use a DNS server.