Releasing names

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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

Releasing names

Name release occurs when a WINS client computer finishes using a particular name, when a proper shutdown occurs. In releasing its name, a WINS client notifies its WINS server (or potentially other computers on the network) that it is no longer using its registered name.

As shown in the following figure, when a WINS-enabled client (HOST-C) releases its name, the following steps occur:

How clients release names in WINS

  1. The computer named HOST-C either shuts down properly or a user enters the nbtstat -RR command, initiating a name release request to be sent to the WINS server, WINS-A.

  2. WINS-A marks the related database entry for HOST-C as released.

    If the entry remains released for a period of time, WINS-A marks the entry as tombstoned, updates the version ID for the entry, and notifies other WINS servers of the change.

  3. WINS-A returns a release confirmation message to the WINS client, HOST-C.

If a name entry is marked as released, the WINS server can immediately update or revise a marked name entry when a new registration request arrives from a WINS client with the same name but with a different IP address. This is possible because the WINS database shows that the WINS client at the old IP address is no longer using that name. For example, this can happen when a DHCP-enabled laptop changes subnets.

Name release is most often used to simplify WINS registration for clients that shut down and restart on the network. If a computer released its name during a normal shutdown, the WINS server does not challenge the name when the computer reconnects. If a proper shutdown did not occur, the name registration with a new IP address causes the WINS server to challenge the previous registration. When the challenge fails (because the client computer is no longer using the old IP address), the registration succeeds.

In some cases, a client is not able to release its name by contacting the WINS server, so broadcasts must be used to release a name. This can happen when a WINS-enabled client shuts down without receiving confirmation of its name release by the WINS server.