SDN Explained: Control Plane, Data Plane and OpenFlow for Network+
Software-defined networking separates the part of a network device that decides where traffic should go from the part that actually forwards it. Those two functions are the control plane and the data plane , and on a traditional switch or router they live in the same box. SDN pulls the control plane out of every device and centralizes it in a controller, so the network is configured once as a whole rather than device by device. Understand that sentence and the rest follows. Everything else — the benefits, the risks, the terminology — is a consequence of that one architectural move. The Three Planes CompTIA tests all three, and mixing them up is the common error. Control plane. Decides how traffic should be handled. Routing protocols, spanning tree , MAC learning, and the logic that builds forwarding tables. In SDN this moves to the controller. Data plane (also called the forwarding plane). Actually moves packets, according to the tables the control plane produced. This ...