Patent ID: 7739405

Claim:
An apparatus for managing multicast groups in an InfiniBand system area network, the apparatus comprising: InfiniBand end nodes in the InfiniBand system area network being final destinations for packets, said InfiniBand end nodes comprising a computer recordable-type medium; said InfiniBand end nodes do not include switches or routers, and packets are not routed through said InfiniBand end nodes; a Subnet Administration in a first InfiniBand end node that receives a join request from a second InfiniBand end node for joining a multicast group, wherein the second InfiniBand end node is connected to a first switch and wherein the join request is a send-without-receive request that specifies that the second InfiniBand end node is to be a send-without-receive member of the multicast group that can send packets but will not receive packets, and wherein the first InfiniBand end node is included within the InfiniBand system area network, and further wherein switches in the InfiniBand system area network route packets from the second InfiniBand end node but do not route any packets to the second InfiniBand end node; the Subnet Administation determines whether the multicast group exists; the Subnet Administration in the first InfiniBand end node creates the multicast group, wherein the multicast group is not created by a switch, wherein when the multicast group is created, the second InfiniBand end node is the only member of the multicast group and the multicast group includes no members that receive packets; and the Subnet Administration routes the first switch to discard all packets for the multicast group if the multicast group does not exist.