A system for providing bandwidth congestion control in a private fabric in a high performance computing environment, comprising: a computer comprising one or more microprocessors; a first subnet provided at the computer, the first subnet comprising a plurality of switches, the plurality 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, wherein each of the host channel adapters comprise at least one host channel adapter port, and wherein the plurality of host channel adapters are interconnected via the plurality of switches, and a plurality of end nodes; wherein an end node ingress bandwidth quota associated with an end node is provided at a host channel adapter, the end node being attached to the host channel adapter; wherein ingress bandwidth is received at the end node of the host channel adapter, the ingress bandwidth exceeding the ingress bandwidth quota of the end node; wherein the ingress bandwidth is received from at least two remote end nodes: wherein the system comprises a target group that is defined on at least one of an inter-switch link between two switches of the plurality of switches or at a port of a switch of the plurality of switches, wherein the target group is configured to define a bandwidth limit on the at least one of an inter-switch link between two switches of the plurality of switches or at a port of a switch of the plurality of switches; wherein a target group repository is stored in memory of the host channel adapter; and wherein the defined target group is recorded in the target group repository. a computer comprising one or more microprocessors; a first subnet provided at the computer, the first subnet comprising a plurality of switches, the plurality 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, wherein each of the host channel adapters comprise at least one host channel adapter port, and wherein the plurality of host channel adapters are interconnected via the plurality of switches, and a plurality of end nodes; a plurality of switches, the plurality 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, wherein each of the host channel adapters comprise at least one host channel adapter port, and wherein the plurality of host channel adapters are interconnected via the plurality of switches, and a plurality of end nodes; wherein an end node ingress bandwidth quota associated with an end node is provided at a host channel adapter, the end node being attached to the host channel adapter; wherein ingress bandwidth is received at the end node of the host channel adapter, the ingress bandwidth exceeding the ingress bandwidth quota of the end node; wherein the ingress bandwidth is received from at least two remote end nodes: wherein the system comprises a target group that is defined on at least one of an inter-switch link between two switches of the plurality of switches or at a port of a switch of the plurality of switches, wherein the target group is configured to define a bandwidth limit on the at least one of an inter-switch link between two switches of the plurality of switches or at a port of a switch of the plurality of switches; wherein a target group repository is stored in memory of the host channel adapter; and wherein the defined target group is recorded in the target group repository. wherein the system comprises a target group that is defined on at least one of an inter-switch link between two switches of the plurality of switches or at a port of a switch of the plurality of switches, wherein the target group is configured to define a bandwidth limit on the at least one of an inter-switch link between two switches of the plurality of switches or at a port of a switch of the plurality of switches; wherein a target group repository is stored in memory of the host channel adapter; and wherein the defined target group is recorded in the target group repository.