How to control the DSProxy process for RPC over HTTP connections in Exchange Server 2003 SP1

After you apply Microsoft Exchange Server 2003 Service Pack 1 (SP1), Outlook clients that use remote procedure call (RPC) over HTTP connections to a server that is running Exchange will use the DSProxy process to access information from global catalog servers. Therefore, if you view server connections in the Exchange Server Connection Status dialog box in the Outlook client, you will see the Exchange computer listed in the Server Name column for the item where the Type column lists Directory. These changes are intentionally made by Exchange 2003 SP1 so that global catalog servers no longer have to be published through the RPC Proxy server.

The registry value that is described in the "More Information" section lets you control this feature so that it can be disabled if it is required.

Warning If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

To override this new behavior, create and set the following registry value on your back-end server that is running Exchange 2003. If this registry value is set, the RFR Service behavior will revert to the pre-SP1 method of returning a global catalog to the referral interface.

To create and to set the registry value, follow these steps:

1. Click Start, click Run, type regedit, and then click OK.
2. Locate and then click the following registry subkey:
   HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MsExchangeSA\Parameters
3. Right-click Parameters, click New, and then click DWORD Value.
   
   New Value #1 is selected.
4. To rename this value, type Do Not Refer HTTP to DSProxy, and then press ENTER.
5. Double-click Do Not Refer HTTP to DSProxy, and then type a value other than zero (0) in the Value box. For example, type 1 in the Value box.

Note If you set the Do Not Refer HTTP to DSProxy value to zero (0), or if this value does not exist, the Exchange computer will use the Exchange 2003 SP1 referral process of using the DSProxy process.

When this registry value has been set, an application event that is similar to the following is logged on the server that is running Exchange:

Event Type: Information
Event Source: MSExchangeSA
Event Category: RFR Interface
Event ID: 9240
Date: 7/1/2004
Time: 2:35:29 PM
User: N/A
Computer: Exchange
Description: The Referral Interface will not refer HTTP clients to DSProxy as per registry setting System\CurrentControlSet\Services\MSExchangeSA\Parameters\Do Not Refer HTTP to DsProxy.

For additional information about the DSProxy process, visit the following Microsoft Web site: