Microsoft KB Archive/841652

= How to configure an RPC over HTTP topology on computers that are running Exchange 2003 with Service Pack 1 =

Article ID: 841652

Article Last Modified on 11/30/2007

-

APPLIES TO


 * Microsoft Exchange Server 2003 Service Pack 1

-





INTRODUCTION
This article describes how to configure a managed remote procedure call (RPC) over HTTP topology on computers that are running Microsoft Exchange Server 2003 with Service Pack 1 (SP1). After you configure an RPC over HTTP topology, you can use Exchange System Manager to designate computers that are running Exchange 2003 with SP1 as front-end servers or as back-end servers for RPC over HTTP.



MORE INFORMATION
In Exchange 2003 SP1, the RPC over HTTP topology verifies a new heuristic bit on the server object. The heuristic bit designates the server as either a managed front-end server or a managed back-end server. To indicate a managed server, the heuristic bit is updated to include the 0x20000000 value. This heuristic bit and the existing ServerRole attribute determine the RPC over HTTP managed topology setting for each server. If the ServerRole attribute is set to 0, the managed server is a back-end server. If the ServerRole attribute is set to 1, the managed server is a front-end server.

You must install Exchange 2003 SP1 on all Exchange front-end servers that you want to use as RPC proxy servers. You can configure managed topology settings that automatically update the  subkey in the registry with back-end server information when the following conditions are true:
 * Your topology uses front-end servers and back-end servers.
 * The RpcProxy service runs on the front-end server.

A managed front-end server that is running Exchange 2003 with SP1 scans the Active Directory directory service for managed back-end servers at 15-minute intervals. If the managed front-end server discovers a new managed back-end server during the scan, the managed front-end server adds the managed back-end server to the setting that is stored in the following registry subkey:

If a subsequent scan does not find the managed back-end server that is listed in the  subkey, the information for that managed back-end server is removed from the registry.

Note You must configure managed back-end servers as targets for the RPC proxy servers before you configure the front-end servers as RPC proxy servers. If you do not configure managed back-end servers first, any back-end servers that are not configured for a managed topology are removed from the  subkey. When you configure the back-end servers before a front-end server is present in the managed topology, you receive an error message that is similar to the following:

There is no RPC-HTTP front-end in your Exchange organization.

You can configure computers that have not been upgraded to Exchange Server 2003 SP1 as back-end servers. However, you will need to use an ESM console on a computer with Exchange Server 2003 SP1 installed to configure a computer as a managed BE server.

To designate computers that are running Exchange 2003 with SP1 as managed back-end servers, follow these steps in Exchange System Manager.

Note You must configure managed back-end servers first. If you do not configure managed back-end servers first, connections that use RPC over HTTP may not function.
 * 1) Click Start, point to Programs, point to Microsoft Exchange, and then click System Manager.
 * 2) In the left pane, expand Servers.
 * 3) Right-click the server that you want to configure as a managed back-end server, and then click Properties.
 * 4) On the RPC-HTTP tab, click RPC-HTTP back-end server, and then click OK.

After you configure the back-end servers, follow these steps in Exchange System Manager to designate the managed front-end servers:
 * 1) Click Start, point to Programs, point to Microsoft Exchange, and then click System Manager.
 * 2) In the left pane, expand Servers.
 * 3) Right-click the server that you want to configure as a managed front-end server, and then click Properties.
 * 4) On the General tab, click This is a front-end server, and then click OK.
 * 5) On the RPC-HTTP tab, click RPC-HTTP front-end server, and then click OK.
 * 6) Restart the front-end server.

