Systems and methods for using multiple CE (congestion experienced) flags in both FECN (forward explicit congestion notification) and BECN (backward explicit congestion notification) in a high performance computing environment. An exemplary method can provide a first subnet comprising a plurality of switches, a plurality of host channel adapters, and a plurality of end nodes. The method can receive, at an end node attached to a host channel adapter, an ingress packet from a remote end node, wherein the ingress packet traversed at least a portion of the first subnet prior to being received at the end node. The method can, on receiving the ingress packet, send a response message from the end node attached to the host channel adapter to the remote end node, the response message indicating that the ingress packet experienced congestion during the traversal of the at least a portion of the first subnet.