Hack the Route Start free Open app Automation and APIs
Control plane and data plane
Deciding where traffic should go (control plane) against moving each packet by those decisions (data plane).
The control plane builds the tables: routing protocols, spanning tree, MAC learning. The data plane (forwarding plane) looks each packet up in those tables and sends it on, fast and without asking anyone. The management plane is how people reach the device (SSH, SNMP, an API). In a classic network the control plane is distributed: every router runs OSPF and decides for itself. Software-defined networking (SDN) moves it to a controller that sees the whole network, computes the paths and programs every device's tables. The devices keep forwarding if the controller goes away, but nothing changes or reacts to failures until it is back.