This Error event indicates that the Microsoft Exchange Active Directory Topology service did not initiate a remote procedure call (RPC) to Active Directory. RPC is an interprocess communication (IPC) mechanism that enables seamless communication between client and server applications.

In an Exchange environment, the Exchange server that is running on a member server acts as a client to the Active Directory information residing on a domain controller. For more information about RPC, see What Is RPC? at the Microsoft Windows Server TechCenter.

This event may occur if one or more of the following conditions are true:

• The Active Directory Topology service isn't running.
  
  
• The account you are logged in as is not a member of local administrators group on the Exchange server that logged this event.
  
  
• The Active Directory Topology service could not initialize and allocate the local administrator object security identifier (SID) to the RPC.
  
  
• The protocols required for RPC communication could not be verified.
  
  
• The Active Directory Topology service could not register the RPC interface with the RPC runtime application programming interface (API). The RPC runtime API is responsible for initializing RPC.
  
  
• The Active Directory Topology service could not register the RPC endpoints.
  
  

For more information about how RPC works, see How RPC Works at the Microsoft Windows Server TechCenter.

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

• Make sure that the account you are logged in as is a member of local administrators group on the Exchange server that logged this event.
  
  
• Make sure that the Status of the RPC service is Started.
  
  
  • If the Status of the service is Started, stop and then start the service.
    
    
  • If the Status of the service is not set to Started, start the service.
    
    
• Make sure that you can connect to an available domain controller from the Exchange server. To do this, at a command prompt on the Exchange server, run the following command: ping <IP address or NetBIOS name of the domain controller>. This command verifies that required network connectivity for RPC communication is working. For more information, see Microsoft Knowledge Base article 325487, How to troubleshoot network connectivity problems.
  
  
• Use the RPC Connectivity Verification Tool (RPing) to check the RPC connectivity from Exchange server to an available domain controller. RPing is included when you download the Windows Server 2003 tools from the Windows Server 2003 Resource Kit Tools Web site.
  
  

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.