This event indicates that topology discovery determined that there are no suitable domain controllers in the local site. DSAccess will use out-of-site domain controllers. However, they might respond slower, which can cause message queuing and network saturation.

This event may be logged when the following conditions are true:

• No domain controllers exist in the local site.
  
  
• All in-site domain controllers are down or not suitable.
  
  
• Network problems prevent the Exchange server from contacting domain controllers in the local site.
  
  
• Permissions problems exist.
  
  
• Configuration errors exist.
  
  

To resolve this event, do one ore more of the following:

• Make sure that the local site has enough domain controllers for Exchange.
  
  
• Use the nltest /dsgetdc:<domain> /site:<local site name> command to verify that a domain controller can be located in the local site. The NLTest tool is installed with the Windows support tools.
  
  
• Check the Application log for related events. The detail in other MSExchange ADAccess events and other events may help determine the root cause of this warning. Increase diagnostic logging for the MSExchange ADAccess\Topology category to Lowest or higher. For detailed information about how to increase logging, see Manage Diagnostic Logging Levels.
  
  
• If MSExchange ADAccess Event ID 2080 is logged, no suitable global catalogs may have been found when initial topology discovery completed. Review that event to determine which domain controllers have been contacted and if they are unsuitable for any reasons. Correct any problems as indicated by the event description. For more information, see Microsoft Knowledge Base article 316300, Event ID 2080 from MSExchangeDSAccess.
  
  
• If MSExchange ADAccess Event ID 2070 is logged, a global catalog may be down or is unreachable. Review the event for more information about why each domain controller has become unsuitable. ADAccess found no suitable global catalogs when initial topology discovery completed.
  
  
• Use the Ping or PathPing command-line tools to test basic connectivity. Use Ping to isolate network hardware problems and incompatible configurations. Use PathPing to detect packet loss over multiple-hop trips. For more information, see Microsoft Knowledge Base article 325487, How to troubleshoot network connectivity problems.
  
  
• Run the Dcdiag command-line tool to test domain controller health. To do this, run dcdiag /s:<Domain Controller Name> at a command prompt on the Exchange server. Use the output of Dcdiag to discover the root cause of any failures or warnings that it reports. For more information, see Dcdiag Overview at the Windows Server TechCenter.
  
  

For more information about the Get-EventLogLevel and Set-EventLogLevel diagnostic logging cmdlets, see the following topics:

• get-eventloglevel
  
  
• Set-EventLogLevel
  
  

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.