Setting Primary and secondary WINS server options (150737)

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When any WINS enabled computer is booted it must register a variety of services with WINS. Commonly a computer has a Primary and Secondary WINS address configured in the TCP/IP setup. If the Primary WINS does not respond to the registrations, the computer tries the Secondary WINS.

For additional information on the services that can be registered, please see the following article(s) in the Microsoft Knowledge Base:

119495List of Names Registered with WINS Service

Generally, most clients and servers should be configured with a Primary and Secondary WINS address, however caution must be taken with how a WINS server is itself configured. A WINS server eventually registers its services in its own local WINS database, regardless of whether it points to itself or not (either Primary, Secondary, or none). Registering with itself and another WINS server can cause problems when it comes to replication and renewal of these entries.

For example, if you have a WINS server ("Srv1") that points to itself as Primary and points to another WINS as Secondary ("Wins2"). When Srv1 is booted, it usually tries to register its services before its own WINS Service is started. Since those registrations fail, it tries to register them at Wins2. If Wins2 is available, it accepts the registration requests. However, not all the services are registered at Wins2, because as these registration requests are made, Srv1 continues to check its local WINS service. Once the service is running, it switches back to it and continues registering locally.

After replication has occurred between Srv1 and Wins2, both databases show this ownership:

This potentially problematic condition is referred to as "split registration."

At this point, Srv1 has reverted to re-registering locally, however it takes a while before you can see it. Meanwhile, Srv1 and Wins2 are replicating the split registration mappings to other WINS servers. Eventually these replicas should be reconciled at the remote WINS (that is, the Wins2 replicas are replaced by the newer Srv1 replicas). However, before reconciliation is finished, client connection problems may have occurred, including the inability to connect to a WINS server that split its registration (in this example, Srv1), or the inability to resolve the domain<1c> name that Srv1 registered.

The exact conditions that lead to failure are varied. If your WINS servers are running Windows NT version 3.51 with Service Pack 4 (or greater), these conditions should only be temporary. However, the problem may be more severe depending on your replication scheme or if you are running pre- Service Pack 4 WINS servers.



Another faulty configuration is setting a remote IP address (in this example, Wins2) as Primary while setting the local WINS (Srv1) as Secondary. In this case, Srv1 will eventually stop refreshing its NetBIOS lease at Wins2, and will begin registering locally. Depending on your WINS replication scheme, this may cause connection problems.