Error message when you call the OpenCluster function against a Windows Server 2008 cluster from Windows XP or from Windows Server 2003: "The RPC Server is unavailable"

On a computer that is running Windows XP or Windows Server 2003, you call the OpenCluster function against a Windows Server 2008 cluster on a remote server. In this case, you experience a delay of one minute. Then, you receive the following error message: Note This behavior does not occur if you call the OpenCluster function from Windows Server 2008.

This behavior occurs in Windows XP and in Windows Server 2003 because remote procedure calls (RPC) use User Datagram Protocol (UDP) ports to contact the Cluster service on a remote server.

Windows Server 2008 no longer supports UDP ports in RPC communication. Computers that are running Windows Server 2008 and Windows Vista cannot call the OpenCluster function against a cluster that is running Windows Server 2003 or Windows 2000 Server. And, computers that are running Windows Server 2003, Windows XP, and Windows 2000, cannot call the OpenCluster function against a cluster that is running Windows Server 2008. To remotely manage these clusters, use the Failover Cluster WMI provider.

For more information about the Failover Cluster WMI provider, visit the following Microsoft Web site:

This behavior is by design.

For more information about the OpenCluster function, visit the following Microsoft Web site: