Routing Engine: Configuration parameter is non-default

[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: 2005-11-18

The Microsoft® Exchange Server Analyzer Tool reads the following registry entry to determine whether the Active Directory® directory service read interval for the Exchange routing engine setting has been modified from the default setting:


If the Exchange Server Analyzer finds that the value data for ReloadOsInterval is set to anything other than 3600, a non-default configuration message is displayed.

The ReloadOsInterval value is used to specify the interval at which routing link state information is updated between servers running Exchange. Exchange uses routing link state information so that each server can determine the most inexpensive route to deliver a message, and also whether the connectors that make up the route are functioning. By default, Exchange servers read link state information from Active Directory every 3,600 seconds, which is 1 hour.

In certain situations, routing status information may not be dynamically propagated correctly across servers throughout an Exchange organization. Some servers in the organization continue to operate with old and possibly incorrect routing status information. An outcome of this situation may include new connectors that do not appear when you view a remote routing group by using the WinRoute tool (Winroute.exe). You can use the WinRoute tool to verify that link state information is propagating. To verify that information is propagating, use the WinRoute tool to view the link state information from several different locations in the Exchange organization, and then compare the version numbers for each routing group. The WinRoute tool connects to the link state port on an Exchange Server computer and extracts the link state information for the Exchange organization. Although link state information is a series of globally unique identifiers (GUIDs), WinRoute matches the GUIDs of connectors and of bridgehead servers to objects in Active Directory and presents the information in a readable format.

This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore the registry if a problem occurs. For information about how to restore the registry, view the "Restore the Registry" Help topic in Regedit.exe or Regedt32.exe.
To revert to the default configuration
  1. Open a registry editor such as Regedit.exe or Regedt32.exe.

  2. Navigate to: HKLM\SYSTEM\CurrentControlSet\Services\RESvc\Parameters

  3. In the right pane, double-click ReloadOsInterval.

  4. In the Value data box, type 3600, and then click OK.

  5. Close the registry editor.

Before you edit the registry, and for information about how to edit the registry, see Microsoft Knowledge Base article 256986, "Description of the Microsoft Windows registry" (

For more information about routing and link state information, see the following Knowledge Base articles:

To download WinRoute, a tool that helps you determine the link state information known to the routing master, see "Exchange Server WinRoute" (