Topic Last Modified: 2008-10-01

The Microsoft® Exchange Server Analyzer Tool queries the Active Directory® directory service to determine the value of the msExchRoutingMasterDN attribute for each Routing Group container. If the Exchange Server Analyzer finds that the value for the msExchRoutingMasterDN attribute does not contain a valid server name, and the attribute does not contain the string "DEL:", a warning is displayed.

This problem can occur if the previous routing group master was decommissioned or was incorrectly removed from the topology. Without the routing group master, Exchange will not be able to correctly update or maintain the routing topology.

This is not an issue that applies to an Exchange Server 2007 environment.

When you create a routing group, the first server in that routing group is assigned the role of routing group master. The routing group master maintains current link state information for its routing group and propagates it to the other servers within the routing group. The routing group master monitors the routing configuration that is written in Active Directory for its routing group only. Member servers can communicate any connector state or server availability information to the routing group master. For example, if a member server tries to contact another server in a different routing group over a connector, and this link is unavailable, the member server immediately notifies the routing group master. Likewise, when a non-master server receives new link state information, it immediately transfers the connector state information to the routing group master, so that other servers can receive the information about the routing change.

To correct this warning

  1. In Exchange System Manager, and under Administrative Groups, expand AdministrativeGroup, and then expand Routing Groups.

  2. Expand the routing group, and then click Members.

  3. In the right pane, right-click the Exchange computer that you want to configure as the routing group master, and then click Set as Master.

For more information about routing group masters, see "Configuring a Routing Topology" in Exchange Server 2003 Transport and Routing Guide (