Active Directory server down or unreachable

[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at]  

Topic Last Modified: 2005-11-17

The Microsoft® Exchange Server Analyzer Tool uses remote procedure calls (RPCs) to read the CurrentVersion string value from the following registry key on the Active Directory® directory server:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\CurrentVersion

On a computer running Microsoft Windows® 2000 Server, the expected value for the CurrentVersion string is 5.0. On a computer running Windows Server™ 2003, the expected value is 5.2.

If the Exchange Server Analyzer cannot read this registry value for any reason, an error is displayed.

To correct this error

  1. Ensure that the directory server has been started and is connected to the network.

  2. Use the PING command to determine if the directory server is reachable.

  3. If there is a firewall in place, check to see if RPC ports are blocked.

  4. Ensure that the Remote Registry service on the directory server has been started.

  5. Check the permissions for the account under which the Exchange Server Analyzer is running to ensure that it has sufficient permissions to read the registry on the Active Directory server.

For more information about troubleshooting network connectivity problems, see the following: