|Message:||Process %1 (PID=%2). Exchange Active Directory Provider lost contact with domain controller %3. Error was 0x%4 (%6) (%5). Exchange Active Directory Provider will attempt to reconnect with this domain controller when it is reachable.|
This Information event indicates that the Active Directory Provider component on the Exchange server lost contact with the domain controller specified in the Description section of the event. The error code will be in the format 0x800409ZZ, where ZZ is the hexadecimal value of a standard LDAP error. For more information about LDAP error codes, see Microsoft Knowledge Base article 218185, Microsoft LDAP Error Codes.
This event is logged when logging for MSExchangeADAccess\Topology is set to Minimum or higher. This event may be logged when the following conditions are true:
Typically, no action is necessary. If this event is logged during planned downtime, you can safely ignore this event as long as there is ample capacity in other domain controllers and global catalog servers. If the event is not logged during planned downtime, DSAccess tries to reuse this domain controller automatically after some time period and reconnects when the domain controller is reachable.
To resolve this event, do one or more of the following:
If you are not already doing so, consider running the tools that Microsoft Exchange offers to help administrators analyze and troubleshoot their Exchange environment. These tools can help you make sure that your configuration is in line with Microsoft best practices. They can also help you identify and resolve performance issues, improve mail flow, and better manage disaster recovery scenarios. Go to the Toolbox node of the Exchange Management Console to run these tools now. For more information about these tools, see Toolbox in the Exchange Server 2007 Help.