CPM filters are hardware-based filters used to restrict traffic from the line cards directed to the control processor. This filtering is performed by the Fast Path (FP) network processor and it uses no resources on the main CPU.
CPM filters filter traffic is extracted from the data plane and sent to the CPM for processing. Packets from all network and access ports are filtered. Packets originating from a management Ethernet port can be filtered using management access filters. See Management access filter for more information.