CPM filters are hardware-based filters used to restrict traffic from the line cards directed to the CPM CPU, such as control and management packets. This filtering is performed by the CPM complex and consumes no resources on the CPM CPU.
Packets from all network and access ports extracted to the CPM CPU are filtered by the CPM filter policy. Packets originating from a management Ethernet port can be filtered using management access filters, see Management Access Filter for more information.