The packets that are destined for the CPU are prioritized based on the application. Some of the applications that are prioritized are Layer 2 data packets (a copy of which is sent to CPU for MAC learning), EFM, CFM, STP, LACP, and ICMP. The packets destined for the CPU are classified internally and are put into the correct CPU queue. These packets are rate-limited to prevent DoS attacks. The software programs the classification entries to identify these packets and assigns appropriate bandwidth and priority to them. It is not configurable by the user.