Topic Last Modified: 2005-11-18

The Microsoft® Exchange Server Analyzer Tool reads the following registry entry to determine the defined role for each network interface resource in the Exchange server cluster:


A value of 1 indicates the network resource has been configured as a dedicated private (heartbeat) network. A value of 2 indicates the network resource has been configured as a dedicated public network (client access). A value of 3 indicates the network resource has been configured as a mixed network that allows both heartbeat traffic and client access traffic.

The Exchange Server Analyzer queries the Win32_Service Microsoft Windows® Management Instrumentation (WMI) class to determine the value of the Started key for the Cluster service (ClusSvc). A value of True indicates the Cluster service is started and a value of False indicates the Cluster service is not running.

If the Exchange Server Analyzer does not find a network resource in an Exchange cluster configured as a dedicated private network, a warning is displayed.

Configuring a dedicated private network to use for the cluster heartbeat is a recommended best practice for all Exchange Server clusters. Communication between nodes is critical for smooth cluster operations. You must configure the networks that you use for cluster communication optimally and follow all hardware compatibility list requirements. For networking configuration, two or more independent networks must connect the nodes of a cluster to avoid a single point of failure. Using two local area networks is typical. Microsoft Product Support Services does not support the configuration of a cluster with nodes connected by only one network.

To correct this warning

  1. If not already present, add network interface cards to each node in the Exchange cluster and configure the network interface cards as a private network in Cluster Administrator.

  2. If additional network cards are present but being used for mixed networks, you should modify the configuration by re-configuring the appropriate networks to act as a dedicated private network.

For more information about cluster heartbeat networks, see the following Microsoft Knowledge Base articles:

For additional details, review the document, Exchange Server 2003 Cluster Configuration Checklist (