DHCP Scope delay is not configured correctly

Microsoft.Windows.2008R2.DHCP.Server.Monitor.DelayOffer (UnitMonitor)

Split-scope configuration with delay employs a secondary DHCP server with a time delay that is configured in its scope properties. The time delay on the secondary DHCP server causes it to respond with a delay to DHCP DISCOVER requests from DHCP clients, enabling the primary DHCP server to respond to and accept the DHCPOFFER first. This feature is available only for IPv4 network and not for IPv6 network as in case of latter exhaustion of addresses is not an issue.

Knowledge Base article:

Summary

The feature of delay configuration of scope has its significance for Split-scope deployments; where in the delay configured on the scope of secondary server would prevent the exhaustion of its IP addresses especially during the need of failover. The time delay on the secondary DHCP server causes it to respond with a delay to DHCP DISCOVER requests from DHCP clients, enabling the primary DHCP server to respond to and accept the DHCPOFFER first.

This feature is available only for IPv4 network and not for IPv6 network as in case of latter exhaustion of addresses is not an issue.

Causes

Clients are not obtaining leases from the DHCP Server because:

The configured subnet prefix belongs to a non-unicast or link local address range.
The available IP addresses on the scope have exhausted.

Resolutions

Resolution: Configure a valid subnet prefix and/or a valid subnet delay

Change the subnet delay value

To perform these procedures, you must be a member of the Administrators group, or you must have been delegated the appropriate authority.

To change the delay value:

At the DHCP server, click Start, point to Administrative Tools, and then click DHCP.
In the DHCP console tree, right-click the scope you want to configure, and then click Properties.
On the Advanced tab, under Delay configuration, type the new value for a subnet delay that is between 0 to 1000 ms.

Additional

To perform these procedures, you must be a member of theAdministratorsgroup, or you must have been delegated the appropriate authority.

To verify that clients are getting leased addresses from the DHCP server:

At the DHCP-enabled client computer, clickStart, clickRun, and then typecmd.
To verify the lease of the client with a DHCP server, typeipconfig /allto view lease-status information.
If the client has a validly leased IP address, theipconfig /allcommand displays a date and time forLease Obtainedand Lease Expires.

Element properties:

Target

Microsoft.Windows.2008R2.DHCP.Server.Role

Parent Monitor

System.Health.ConfigurationState

Category

ConfigurationHealth

Enabled

True

Alert Generate

True

Alert Severity

MatchMonitorHealth

Alert Priority

Normal

Alert Auto Resolve

True

Monitor Type

Microsoft.Windows.SingleEventLogManualReset2StateMonitorType

Remotable

True

Accessibility

Public

Alert Message

DHCP Scope delay is not configured correctly

DHCP scope delay facilitates prevention of exhaustion of IP addresses at scope level especially for the deployments catering to redundancy/high-availability scenarios like Split-Scope. This feature is available only for IPv4 network and not for IPv6 network as in case of latter exhaustion of addresses is not an issue. This alert is due to invalid delay configuration or due to number of pending DHCPOFFER messages for delayed transmission to the client has exceeded the server's capacity of 1000 pending messages.

RunAs

Default

Source Code:

<UnitMonitor ID="Microsoft.Windows.2008R2.DHCP.Server.Monitor.DelayOffer" Accessibility="Public" Enabled="true" Target="Microsoft.Windows.2008R2.DHCP.Server.Role" ParentMonitorID="Health!System.Health.ConfigurationState" Remotable="true" Priority="Normal" TypeID="Windows!Microsoft.Windows.SingleEventLogManualReset2StateMonitorType" ConfirmDelivery="true">

  <Category>ConfigurationHealth</Category>

  <AlertSettings AlertMessage="Microsoft.Windows.2008R2.DHCP.Server.Monitor.DelayOffer_AlertMessageResourceID">

    <AlertOnState>Warning</AlertOnState>

    <AutoResolve>true</AutoResolve>

    <AlertPriority>Normal</AlertPriority>

    <AlertSeverity>MatchMonitorHealth</AlertSeverity>

  </AlertSettings>

  <OperationalStates>

    <OperationalState ID="UIGeneratedOpStateId9b8b1d6ecbc645ffa2f4e3e260ac6e47" MonitorTypeStateID="EventRaised" HealthState="Warning"/>

    <OperationalState ID="UIGeneratedOpStateId11e6260996934a76af77f236b5219505" MonitorTypeStateID="ManualResetEventRaised" HealthState="Success"/>

  </OperationalStates>

  <Configuration>

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

    <LogName>System</LogName>

    <Expression>

      <And>

        <Expression>

          <RegExExpression>

            <ValueExpression>

              <XPathQuery Type="UnsignedInteger">EventDisplayNumber</XPathQuery>

            </ValueExpression>

            <Operator>MatchesRegularExpression</Operator>

            <Pattern>^(1339|20091|20092|1338)$</Pattern>

          </RegExExpression>

        </Expression>

        <Expression>

          <RegExExpression>

            <ValueExpression>

              <XPathQuery Type="String">PublisherName</XPathQuery>

            </ValueExpression>

            <Operator>ContainsSubstring</Operator>

            <Pattern>DHCP</Pattern>

          </RegExExpression>

        </Expression>

      </And>

    </Expression>

  </Configuration>

</UnitMonitor>