Applies to: Exchange Server 2007 SP3, Exchange Server 2007 SP2, Exchange Server 2007 SP1, Exchange Server 2007
Topic Last Modified: 2006-12-20

This topic explains how to use Registry Editor to suppress propagation of minor link state updates between routing groups in Microsoft Exchange Server 2007 and Exchange Server 2003.

We recommend that you perform this procedure if the following conditions are true:

The first routing group connector is created when the first Hub Transport server role is installed on a computer in the Exchange organization. Before you create additional routing group connectors, perform this procedure on every Exchange 2000 and Exchange 2003 server in the organization. When you suppress minor link state updates, the servers that are running Exchange 2000 and Exchange 2003 will not mark connectors as down. This procedure will make sure that earlier versions of Exchange will only use least cost routing and will not try to calculate an alternative route.

The purpose of this procedure is to make sure that routing loops cannot occur. Exchange 2007 does not use a link state routing table and does not support relay of link state information. If you do not suppress minor link state updates, routing loops may occur. For more information about how routing occurs in an Exchange organization that includes Exchange 2007 servers and Exchange 2003 or Exchange 2000 servers, see Message Routing in a Coexistence Environment.

Before You Begin

Before you suppress link state updates, you should read Planning for Coexistence.

To perform this procedure, you must log on to the Exchange 2000 or Exchange 2003 server by using an account that is delegated the following:

  • Membership in the local Administrators group

For more information about permissions, delegating roles, and the rights that are required to administer Microsoft Exchange Server 2007, see Permission Considerations.

Incorrectly editing the registry can cause serious problems that may require you to reinstall your operating system. Problems resulting from editing the registry incorrectly may not be able to be resolved. Before editing the registry, back up any valuable data.


To suppress link state updates on Exchange 2003 or Exchange 2000

  1. Open Registry Editor.

  2. Locate HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\RESvc\Parameters.

  3. Right-click Parameters and select New | DWORD value. Name the new DWORD value SuppressStateChanges.

  4. Double-click SuppressStateChanges.

  5. In the Value data field, enter 1.

  6. Close Registry Editor and then restart the Simple Mail Transfer Protocol (SMTP) service, the Microsoft Exchange Routing Engine service, and the Microsoft Exchange MTA Stacks services for the change to take effect.

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