What term describes the virtual network layer built on top of the physical infrastructure in SDN architectures?
Correct Answer: B
Detailed Explanation: In SDN architectures, the overlay network is the virtual layer that is built atop the physical underlay. The overlay network provides logical segmentation and abstraction, allowing virtual networks to be created independent of the physical hardware. This separation enables rapid provisioning, improved security, and flexible management of virtualized services without altering the underlying physical infrastructure.
This CCNA practice question helps students prepare for Cisco networking certification exams by testing knowledge of network fundamentals, routing, switching, and network security concepts.