Patent ID: 8612559

Claim:
A system comprising: a centralized control processor configured to conduct a central snoop of upstream switches and to monitor for join messages, from hosts, that are received by virtual machines (VMs) of servers, the centralized control processor further configured to communicate with first and second computer servers, wherein first and second VMs are implemented by the first server and a third VM implemented by the second server, wherein incoming multicast messages received by the first server are communicated to a first virtual switch, which is associated with the first server, if they include a destination address associated with the first VM or the second VM, wherein the centralized control processor is configured to evaluate incoming join messages to be received by the first and second VMs, wherein, prior to migrating the first VM to a third server, the centralized control processor causes the third server to send a join report to join a multicast group to which the first VM belongs if the third server is not already a member of the multicast group, and wherein join/exit reports are used to enroll and disenroll the first and second servers and the first and second VMs into multicast groups, and wherein the join/exit reports are sent in a unidirectional fashion in one direction on a link of origination and not sent in an opposite direction on the link of origination.