Control plane

This is the part of the network that takes care of carrying the signaling traffic and routing operations in a router using control packets. The control packets begin from a router or are destined for a router. A routing table has the details of the destination address and the outgoing interfaces; the logic of the control plane defines how certain packets are to be discarded or offered with high-quality service. 

Depending on the router implementation and configuration, the control plane creates a separate forwarding information base (FIB), but the data plane uses the FIB to look up and send the packets at a high speed. The following diagram shows the operation of the control plane:

It also takes care of other activities such as: 

• Interface state management (PPP, LACP)
• Connectivity management
• Device discovery—Neighbor (hello mechanisms)
• Device reachability information
• Provisioning services

In the event there is a failure in the control plane, the router will lose the ability to learn the routing information dynamically.