NLB Cluster %2 %1: Host %3 MAY be a Windows 2000 or NT 4.0 host participating in a cluster utilizing virtual cluster support. Virtual Clusters are only supported in a homogeneous Windows Server 2003 cluster. %4

Details
Product:	Windows Operating System
Event ID:	54
Source:	WLBS
Version:	5.2
Symbolic Name:	MSG_WARN_VIRTUAL_CLUSTERS
Message:	NLB Cluster %2 %1: Host %3 MAY be a Windows 2000 or NT 4.0 host participating in a cluster utilizing virtual cluster support. Virtual Clusters are only supported in a homogeneous Windows Server 2003 cluster. %4

Explanation
Virtual clusters, which are Network Load Balancing (NLB) clusters where specific port rules are assigned to specific Virtual IP addresses, are configured on this host, but at least one host in this cluster has one or more port rules that are not valid and appear to be missing the Virtual IP address specification. Therefore, either: A Windows 2000 or Windows NT 4.0 host exists in the cluster. Virtual clusters require a cluster containing only hosts running products in the Windows Server 2003 family, or A Windows Server 2003 host with an incorrectly configured port rule exists in the cluster. The cluster will not converge until the problem is corrected.

User Action
If there is a Windows 2000 or Windows NT 4.0 host in the cluster, either remove it or stop using virtual clusters on the Windows Server 2003 hosts. If the cluster contains only Windows Server 2003 hosts, then use NLB Manager to check the port rule configuration of all hosts to ensure that all hosts have compatible port rule configurations. For more information about virtual clusters and port rules, see NLB in Help and Support.