The MicrosoftNLB_ClusterSetting::LoadAllSettings method does not read modifications to the UnicastInterHostCommSupport registry entry in Windows Server 2003

You want to configure Network Load Balancing (NLB). If you use the MicrosoftNLB_ClusterSetting::AccessNLBRegParam Windows Management Instrumentation (WMI) method to modify the UnicastInterHostCommSupport registry entry, and you then use the MicrosoftNLB_ClusterSetting::LoadAllSettings method, unicast interhost communication between cluster nodes does not work as you expect. For example, you cannot communicate between the cluster nodes by using the Ping command.

You expect the modified UnicastInterHostCommSupport registry entry to be read when you run the MicrosoftNLB_ClusterSetting::LoadAllSettings method.

This problem occurs because the LoadAllSettings method does not recognize the entries that are set by the AccessNLBRegParam method. Therefore, the modification of the UnicastInterHostCommSupport registry entry by using the AccessNLBRegParam method does not take effect when you call the LoadAllSettings method. In this scenario, the call to reload all settings is considered to be a no-operation (NO-OP) call.

Note If other NLB settings are changed at the same time that the UnicastInterHostCommSupport registry entry is set, the new registry entry is correctly picked up by LoadAllSettings, because the reload operation is no longer considered to be a NO-OP call. Examples of these NLB settings are host IDs and dedicated IP addresses.

To work around this problem, after you call the MicrosoftNLB_ClusterSetting::AccessNLBRegParam WMI method, type the Wlbs.exe reload command at a command prompt.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

For additional information about how to troubleshoot Network Load Balancing clusters, visit the following Microsoft Web site:For additional information about Network Load Balancing WMI classes, visit the following Microsoft Web site: