Which protocol is commonly used as a southbound API in SDN environments to communicate between the controller and network devices?
Correct Answer: A
Detailed Explanation: OpenFlow is a widely adopted southbound protocol in SDN that allows the SDN controller to communicate directly with network devices. It enables the controller to install, update, and delete flow entries in the devices’ forwarding tables, thereby directing traffic according to centralized policies. This protocol is essential for enabling the dynamic, programmable control that defines SDN.
This CCNA practice question helps students prepare for Cisco networking certification exams by testing knowledge of network fundamentals, routing, switching, and network security concepts.