Performance Measuring: Conflict Check Queue Length.

Performance_Measuring__Conflict_Check_Queue_Length._1_Rule (Rule)

Knowledge Base article:

Management Pack

Summary
This counter measures the number of packets waiting in the DHCP 2000 Server queue due to conflict detection. This queue holds messages not responded to while the DHCP 2000 Server performs address conflict detection. Typically, this counter is used to determine if the value for Conflict detection attempts is set too high, or if there is unusually heavy lease traffic at the server.

Causes
Either of the following conditions can trigger this alert: The value for Conflict detection attempts on the Advanced tab of the DHCP 2000 Server properties has been set to a value greater than 0 (especially if it is set to a value higher than 1 or 2). Lease traffic on the DHCP 2000 Server is unusually heavy.

Resolutions
Resolution 1: Open the DHCP administrative tool, and then on the Advanced tab of the properties of this DHCP 2000 Server, set the value of Conflict detection attempts to 1 or 2. For most networks, a retry value of 1 is sufficient. Important Only enable address conflict detection during troubleshooting, for example, as the last step when resolving a corrupted DHCP database. When you are finished troubleshooting, reset the value for Conflict detection attempts to 0. Resolution 2: If lease traffic on the DHCP 2000 Server is unusually heavy, investigate the cause of the increased traffic. For example, use a sniffer to examine network traffic to determine if someone is attempting a denial-of-service attack by using fake DHCP packets.

Element properties:

Target	Microsoft.Windows.Server.DHCP.Microsoft_Windows_2000_DHCP_Servers_Installation
Category	PerformanceCollection
Enabled	True
Instance Name	DHCP Server
Counter Name	Conflict Check Queue Length
Frequency	900
Alert Generate	False
Remotable	True
Comment	Mom2005ID='{BE5B7284-6A8F-4292-B59B-A65A3F1288BC}';MOM2005ComputerGroupID={37B5AB26-6DE0-11D3-945C-0090275A5879}

Member Modules:

ID	Module Type	TypeId	RunAs
_A0C3BED4_346B_486F_901F_7D02A40434D4_	DataSource	System.Mom.BackwardCompatibility.Performance.FilteredDataProvider	Default
CollectPerfData	WriteAction	Microsoft.SystemCenter.CollectPerformanceData	Default
CollectPerfDataWarehouse	WriteAction	Microsoft.SystemCenter.DataWarehouse.PublishPerformanceData	Default
GenerateAlert	WriteAction	System.Mom.BackwardCompatibility.AlertResponse	Default

Source Code:

<Rule ID="Performance_Measuring__Conflict_Check_Queue_Length._1_Rule" Target="Microsoft.Windows.Server.DHCP.Microsoft_Windows_2000_DHCP_Servers_Installation" Enabled="true" ConfirmDelivery="false" Comment="Mom2005ID='{BE5B7284-6A8F-4292-B59B-A65A3F1288BC}';MOM2005ComputerGroupID={37B5AB26-6DE0-11D3-945C-0090275A5879}">

  <Category>PerformanceCollection</Category>

  <DataSources>

    <DataSource ID="_A0C3BED4_346B_486F_901F_7D02A40434D4_" Comment="{A0C3BED4-346B-486F-901F-7D02A40434D4}" TypeID="MomBackwardCompatibility!System.Mom.BackwardCompatibility.Performance.FilteredDataProvider">

      <ComputerName>$Target/Host/Property[Type="WindowsLibrary!Microsoft.Windows.Computer"]/NetworkName$</ComputerName>

      <CounterName>Conflict Check Queue Length</CounterName>

      <ObjectName>DHCP Server</ObjectName>

      <Frequency>900</Frequency>

      <Expression/>

    </DataSource>

  </DataSources>

  <WriteActions>

    <WriteAction ID="GenerateAlert" TypeID="MomBackwardCompatibility!System.Mom.BackwardCompatibility.AlertResponse">

      <AlertGeneration>

        <GenerateAlert>false</GenerateAlert>

      </AlertGeneration>

      <InvokerType>1</InvokerType>

    </WriteAction>

    <WriteAction ID="CollectPerfData" TypeID="SystemCenterLibrary!Microsoft.SystemCenter.CollectPerformanceData"/>

    <WriteAction ID="CollectPerfDataWarehouse" TypeID="DataWarehouseLibrary!Microsoft.SystemCenter.DataWarehouse.PublishPerformanceData"/>

  </WriteActions>

</Rule>