NLB detected an unequal number of dedicated IP (DIP) addresses and network masks

Microsoft.Windows.NetworkLoadBalancing.10.0.NLB.detected.an.unequal.number.of.dedicated.IP.addresses.and.network.masks (Rule)

Knowledge Base article:

Summary

The dedicated IP addresses in Network Load Balancing (NLB) must be properly configured and be able to contact individual NLB cluster hosts. If the dedicated IP address is not configured correctly, you cannot use it to manage the host or for other non-cluster-related communication.

Resolutions

Ensure consistent number of dedicated IP addresses and subnet masks

On all Network Load Balancing (NLB) cluster hosts, the dedicated IP addresses must have an equal number of subnet masks specified. If there are an unequal number, the NLB cluster will continue to operate, but the IP address that has no corresponding network mask will be ignored. To use this IP address, make sure that the number of IP addresses and network masks are the same.

To ensure that the number of dedicated IP addresses is the same as the number of subnet masks:

Element properties:

TargetMicrosoft.Windows.NetworkLoadBalancing.10.0.ServerRole
CategoryAlert
EnabledTrue
Alert GenerateFalse
RemotableTrue

Member Modules:

ID Module Type TypeId RunAs 
DS DataSource Microsoft.Windows.NetworkLoadBalancing.EventProvider Default
WA WriteAction Microsoft.Windows.NetworkLoadBalancing.10.0.GenerateAlert.SuppressByDescription Default
WriteToDB WriteAction Microsoft.Windows.NetworkLoadBalancing.10.0.CollectEvent Default

Source Code:

<Rule ID="Microsoft.Windows.NetworkLoadBalancing.10.0.NLB.detected.an.unequal.number.of.dedicated.IP.addresses.and.network.masks" Enabled="true" Target="Microsoft.Windows.NetworkLoadBalancing.10.0.ServerRole" ConfirmDelivery="true" Remotable="true" Priority="Normal" DiscardLevel="100">
<Category>Alert</Category>
<DataSources>
<DataSource ID="DS" TypeID="NLBLibrary!Microsoft.Windows.NetworkLoadBalancing.EventProvider">
<Criteria>
<SimpleExpression>
<ValueExpression>
<XPathQuery>EventDisplayNumber</XPathQuery>
</ValueExpression>
<Operator>Equal</Operator>
<ValueExpression>
<Value>32</Value>
</ValueExpression>
</SimpleExpression>
</Criteria>
</DataSource>
</DataSources>
<WriteActions>
<WriteAction ID="WA" TypeID="Microsoft.Windows.NetworkLoadBalancing.10.0.GenerateAlert.SuppressByDescription">
<Priority>1</Priority>
<Severity>2</Severity>
<AlertMessageId>$MPElement[Name="Microsoft.Windows.NetworkLoadBalancing.10.0.NLB.detected.an.unequal.number.of.dedicated.IP.addresses.and.network.masks.AlertMessage"]$</AlertMessageId>
<EnableAlert>true</EnableAlert>
</WriteAction>
<WriteAction ID="WriteToDB" TypeID="Microsoft.Windows.NetworkLoadBalancing.10.0.CollectEvent">
<CollectEvent>false</CollectEvent>
</WriteAction>
</WriteActions>
</Rule>