Abstract: Systems and methods for supporting inter subnet control plane protocol for consistent multicast membership and connectivity across multiple subnets in a high performance computing environment. In accordance with an embodiment, by associating a multicast group with an inter-subnet partition, and enforcing a dedicated router port for the multicast group, multicast loop avoidance can be provided for between connected subnets. Because only a single router port is selected as being capable of handling the MC packet, no other router port in the subnet can then pass a multicast packet back to the originating subnet.

Abstract: Systems and methods for supporting SMA level abstractions at router ports for enablement of data traffic in a high performance computing environment. In accordance with an embodiment, a subnet manager in a local subnet is responsible for enabling data traffic between subnets in a high performance computing environment. The SM can configure and set a data attribute at a switch port configured as a router port such that incoming data packets can be checked against the attribute to determine whether the data packet's destination is allowed or disallowed to receive inter-subnet data traffic.

Abstract: Systems and methods for supporting consistent path records across multiple subnets in a high performance computing environment. In accordance with an embodiment, a local inter-subnet manager (ISM) can determine one or more limitations associated with a calculated local path record. The local ISM can, upon receiving information regarding path limitations from a connected subnet, determine which limitations should be applied to inter-subnet traffic.