What are three facts control plane policing？ （）

A、a set of rules that can be established and associated with the ingress and egress ports of the control plane

B、improves performance of the control plane by marking control plane packets with DSCPEF

C、protects the control plane on a router from DoS attacks

D、treats the control plane as a separate entity with its own ingress （input） and egress （output） ports

E、provides the control plane with a separate token bucket

F、enhances security of the control plane by tunneling packets to and from the control plane