Topic Last Modified: 2005-11-18

The Microsoft® Exchange Server Analyzer Tool queries the Win32_NetworkAdapterConfiguration Microsoft Windows® Management Instrumentation (WMI) class to determine whether a value is set for the WINSSecondaryServer key. If the value for this key on an Exchange server is blank, a warning is displayed.

Exchange Server 2003 and Exchange 2000 Server have several NetBIOS dependencies. Additionally, clients running Microsoft Outlook® versions prior to Microsoft Office Outlook 2003 also require NetBIOS name resolution. For example, the following Exchange functionality depends on NetBIOS name resolution:

Depending on your organization's network topology, you may be able to safely ignore this warning. On networks that are made up of a single subnet NetBIOS, broadcasts are typically able to handle the NetBIOS name resolution requirements of an Exchange deployment.

In large organizations, NetBIOS name resolution through broadcasts may not function correctly. Because NetBIOS broadcasts typically do not cross subnets, routed networks require an alternate method for resolving NetBIOS names. The preferred method to do this is Windows Internet Name Service (WINS). WINS provides a distributed database for registering and querying dynamic mappings of NetBIOS names for computers and groups used on your network. WINS maps NetBIOS names to IP addresses and was designed to solve the problems occurring because of NetBIOS name resolution in routed environments. WINS is the best choice for NetBIOS name resolution in routed networks that use NetBIOS over TCP/IP.

Exchange Server 2003 and Exchange 2000 Server operations and functions in a large or sub-netted organization without WINS have not been fully tested. Microsoft requires companies running Exchange on routed or segmented networks to use WINS for NetBIOS name resolution. Running Exchange in a routed or segmented environment without WINS is not supported.

It is recommended that you deploy a fault-tolerant WINS environment that includes at least two WINS servers. WINS servers can act as either a primary WINS server or a secondary WINS server to a client. The difference between primary and secondary WINS servers is the priority in which clients contact them. A primary WINS server is the first server a client contacts to perform its NetBIOS name service operations. A client contacts a secondary WINS server only when a primary WINS server cannot fulfill the request, for example, if it is unavailable when the client makes the request or you cannot resolve a name for the client.

If a primary WINS server does not fulfill a request, the client makes the same request of its secondary WINS server. If more than two WINS servers are configured for the client, the client tries the additional secondary WINS servers until the list is exhausted or one of the WINS servers successfully responds to the request. After a client uses a secondary WINS server, it periodically tries to switch back to its primary WINS server for future name service requests.

It is a best practice to configure at least one secondary WINS server on Exchange server computers on a routed or segmented network.

To correct this warning

  1. Open Network Connections.

  2. Right-click the network connection you want to configure, and then click Properties.

  3. On the General tab (for a local area connection) or the Networking tab (for all other connections), click Internet Protocol (TCP/IP), and then click Properties.

  4. Click Advanced, click the WINS tab, and then click Add.

  5. In TCP/IP WINS server, type the IP address of a secondary WINS server, and then click Add.

  6. Repeat steps 4 and 5 for each additional WINS server IP address you want to add, and then click OK. You can change the order of preference for WINS servers by using the arrow keys.

  7. Make sure Enable NetBIOS over TCP/IP is selected.

  8. Click OK to save your changes.

For more information about the NetBIOS name resolution requirements for Exchange, see the Microsoft Knowledge Base article 837391, "Exchange Server 2003 and Exchange 2000 Server require NetBIOS name resolution for full functionality" (