Windows 2008 supports having clustered nodes that are installed into different network subnets.  For Exchange 2007 SP1 this becomes a configuration used for cluster continuous replication clusters.

In troubleshooting and monitoring clusters customers will often use the test-replicationhealth commandlet to determine the status of replication between two clustered nodes in a continuous cluster replication solution.  When the cluster itself is multi-subnet, the following error is thrown during testing:

The issue is a bug in the way that test-replicationhealth handles cluster networks.  In cluster administrator, under networks, you will see a “network” enumerated for each subnet.  Each of these networks shows all of the cluster interfaces that reside on that network.  In a single subnet cluster, these networks would generally have two interfaces, one for each node.  In a multi-subnet cluster, each network only has a single interface, one for each node.

To view a network and it’s interfaces, select networks from the left hand pane:

Here is an example of a multi-subnet cluster (showing a single interface per network):

Here is an example of a single subnet cluster (showing multiple interfaces per network):

At this time this issue is not scheduled to be corrected in any Exchange 2007 release.

*Updates:

10/19/2009 – Updated to reflect fix release.