A system for supporting Subnet Management Packet based, SMP-based, connectivity checks across virtual router ports in a high performance computing environment, comprising: one or more microprocessors; a first subnet , the first subnet comprising a plurality of switches , the plurality of switches comprising at least a leaf switch, wherein each of the plurality of switches comprise a plurality of switch ports, a plurality of host channel adapters , each host channel adapter comprising at least one host channel adapter port, a plurality of end nodes (201-204), wherein each of the end nodes are associated with at least one host channel adapter of the plurality of host channel adapters, and a subnet manager, the subnet manager running on one of the plurality of switches and the plurality of host channel adapters; characterised in that a switch port of the plurality of switch ports on a switch of the plurality of switches is configured as a router port ; wherein the switch port configured as the router port is logically connected to a virtual router of the first subnet; wherein the subnet manager sends to the switch port of the plurality of switch ports on the switch of the plurality of switches configured as the router port a request packet addressed to the router port, wherein the request packet requests connectivity information beyond the router port; and wherein a subnet management agent, residing on the switch of the plurality of switches, modifies the request packet. one or more microprocessors; a first subnet , the first subnet comprising a plurality of switches , the plurality of switches comprising at least a leaf switch, wherein each of the plurality of switches comprise a plurality of switch ports, a plurality of host channel adapters , each host channel adapter comprising at least one host channel adapter port, a plurality of end nodes (201-204), wherein each of the end nodes are associated with at least one host channel adapter of the plurality of host channel adapters, and a subnet manager, the subnet manager running on one of the plurality of switches and the plurality of host channel adapters; a plurality of switches , the plurality of switches comprising at least a leaf switch, wherein each of the plurality of switches comprise a plurality of switch ports, a plurality of host channel adapters , each host channel adapter comprising at least one host channel adapter port, a plurality of end nodes (201-204), wherein each of the end nodes are associated with at least one host channel adapter of the plurality of host channel adapters, and a subnet manager, the subnet manager running on one of the plurality of switches and the plurality of host channel adapters; characterised in that a switch port of the plurality of switch ports on a switch of the plurality of switches is configured as a router port ; wherein the switch port configured as the router port is logically connected to a virtual router of the first subnet; wherein the subnet manager sends to the switch port of the plurality of switch ports on the switch of the plurality of switches configured as the router port a request packet addressed to the router port, wherein the request packet requests connectivity information beyond the router port; and wherein a subnet management agent, residing on the switch of the plurality of switches, modifies the request packet. <EOS>