This article explains how NLB algorithm works internally from a technical point of view. This article only applies to Windows NT, Windows 2000 Server, Windows Server 2003 and Windows Server 2008.
General rule for a NLB Cluster which applies to each host in the cluster:
1. All port rules (range) defined in a host cluster must be unique across the cluster.
2. Host priority (Default Host) must be unique across the cluster.
3. Cluster mode must be unique across the cluster: either Unicast or Multicast.
General rule for a NLB Cluster which applies to each host in the cluster:
1. All port rules (range) defined in a host cluster must be unique across the cluster.
2. Host priority (Default Host) must be unique across the cluster.
3. Cluster mode must be unique across the cluster: either Unicast or Multicast.