A system and method for priority-based flow control between nodes. In one example, pause deadlocks in a physical loop can be averted by priority-based selection of egress ports to which a packet is forwarded. In one embodiment, if the packet priority matches a configured lossless priority, then the set of internal egress ports is masked such that only the internal ports belonging to the spanning tree remain in the set of internal egress ports. If the packet priority does not match a configured lossless priority, then the set of internal egress ports is masked such that only the internal ports belonging to the shortest path first tree remain in the set of internal egress ports.