Control Plane

In routing, the control plane is the part of the router architecture that is concerned with drawing the network topology, or the information in a (possibly augmented) routing table that defines what to do with incoming packets. Control plane functions, such as participating in routing protocols, run in the architectural control element. In most cases, the routing table contains a list of destination addresses and the outgoing interface(s) associated with them. Control plane logic also can define certain packets to be discarded, as well as preferential treatment of certain packets for which a high quality of service is defined by such mechanisms as differentiated services.

Depending on the specific router implementation, there may be a separate forwarding information base that is populated (i.e., loaded) by the control plane, but used by the forwarding plane to look up packets, at very high speed, and decide how to handle them.\