A technique for managing the utilization of processing resources involves filtering packets that are sent to a CPU for learning before allowing the packets to reach the CPU. The filtering involves determining if related packets have already been allowed to reach the CPU for learning and using the knowledge about related packets to determine if a current packet should be allowed to reach the CPU. In one embodiment, the processing resources of the CPU are conserved by allowing only one packet per flow to reach the CPU for learning. The one packet is used by the CPU to generate the necessary forwarding information and to initiate programming of the hardware-based forwarding table so that subsequent packets of the same flow can be forwarded directly from the hardware-based forwarding engine.