Control Plane Protection

Control Plane Protection or CPPr is an extension of Control Plane Policing (CoPP) (CoPP). Cisco puts it this way:

The Control Plane Protection feature is an extension of the policing functionality provided by the existing Control-Plane Policing feature. The Control-Plane Policing feature allows Quality of Service (QoS) policing of aggregate control-plane traffic destined to the route processor. The Control Plane Protection feature extends this policing functionality by allowing finer policing granularity.

The functionality added with Control Plane Protection includes a traffic classifier, which intercepts traffic and classifies it into three control-plane categories. New port-filtering and queue-thresholding features have also been added. The port-filtering feature provides for policing of packets going to closed or nonlistened TCP/UDP ports, while queue-thresholding limits the number of packets for a specified protocol that will be allowed in the control-plane IP input queue.

Links:

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/qos_plcshp/configuration/15-mt/qos-plcshp-15-mt-book/qos-plcshp-cpp.html