CompTIA Network+ (N10-009)Networking ConceptsHard
A network architect is implementing a software-defined networking (SDN) solution and explains to stakeholders that a centralized controller will make all forwarding decisions and push instructions to switches, which will simply execute those instructions on incoming traffic. Which architectural concept does this describe?
- ASeparation of control plane and data plane
- BZero trust segmentation
- CFull mesh redundancy
- DConvergence of management and data planes
Show answer & explanationAnswer & explanation
Correct answer: A. Separation of control plane and data plane
SDN separates the control plane (decision-making, handled by a centralized controller) from the data plane (packet forwarding, handled by switches), allowing centralized, programmable network management via APIs such as OpenFlow.
Why the other options are wrong
- B. Zero trust segmentation is a security model unrelated to how SDN controllers manage forwarding decisions.
- C. Full mesh redundancy refers to physical topology, not the control/data plane relationship in SDN.
- D. SDN separates rather than converges the control and data planes, the opposite of this description.
SDN Control/Data Plane Separation
Software-Defined Networking separates the control plane (centralized decision-making) from the data plane (packet forwarding by switches), enabling centralized, programmable network control.
- Control plane = decision-making, centralized controller
- Data plane = packet forwarding, executed by switches
- Often implemented using APIs like OpenFlow
Memory trick: SDN = 'Smart brain (controller) directs dumb hands (switches)'.