The virtual switch in a cluster

It is vital to remember that the virtual switch is not a cluster-controlled resource. Because the switch itself has no protocols bound, the cluster does not, and cannot recognize it as being a network resource. All virtual switches on all hosts are known only to their owning hosts. In order for a virtual machine to migrate freely between nodes, the switches that its virtual adapters connect to must be able to find a switch with exactly the same name and exactly the same parameters on each node. Otherwise, Live Migrations will fail and Quick Migrations will result in virtual machines that won't start. The cluster itself cannot, and will not, police these switch names to ensure consistency (although the Cluster Validation Wizard will warn you about it).