Topic Last Modified: 2010-07-25

The Microsoft Exchange Server 2010 Management Pack for System Center Operations Manager includes a performance data collection engine that is used to query performance counter objects on computers running Exchange 2010. For this Operations Manager rule, data is collected by using the performance counter specified in the Details table.

To review the value of the performance counter that generated this alert, in Operations Manager, double-click this alert, and then click the General tab. Review the description of the alert that includes the variables specific to your environment.


Product Name


Product Version

14.0 (Exchange 2010)

Object Name

MSExchange ADAccess Domain Controllers

Counter Name

LDAP Searches timed out per minute

Sample Interval


Server Role

Ex14. Common

Warning Threshold


Rule Path

Microsoft Exchange Server/Exchange 2010/Common Components/Domain Controller

Rule Name

LDAP Searches timed out per minute - sustained for 5 minutes - Red(>20).


The LDAP Searches timed out per minute performance counter shows the number of LDAP search requests that timed out during the last minute. The average value should be less than 10 and the maximum value should not exceed 20.

This event indicates that more than 20 LDAP searches per minute timed out for five minutes. This can be caused by a network connectivity loss between the Exchange Server server and the Active Directory domain controller, by a problem on the domain controller, or by severe performance problems.

User Action

To resolve this error, do one or more of the following:

  • Verify that there is network connectivity between the Exchange server and the domain controllers it uses.

  • Verify that the domain controllers the Exchange server uses are available.

  • Verify that the associated domain controllers are not experiencing severe performance problems. You can investigate CPU usage on the Active Directory servers. You can also investigate disk and memory bottlenecks on the Active Directory servers.

If the problem persists, contact Microsoft Customer Support Services. For information about how to contact support, visit Microsoft Help and Support.

For More Information

If you are not already doing so, consider running the Exchange tools created to help you analyze and troubleshoot your Exchange environment. These tools can help make sure that your configuration aligns with Microsoft best practices. They can also help you identify and resolve performance issues, improve mail flow, and better manage disaster recovery scenarios. To run these tools, go to the Toolbox node of the Exchange Management Console. To learn more about these tools, see Managing Tools in the Toolbox.