Which of the following is a typical failure mode when a vSmart or vBond becomes unavailable?

• A. OMP updates stop
• B. Loss of control-plane signaling
• C. QoS policy misalignment
• D. Tunnels reconfigure normally

Answer: (B)

In this SD-WAN setup, vSmart is the hub for the control plane and vBond handles onboarding and reachability. They drive the overlay by distributing policies and routing information to the edge devices. If either component becomes unavailable, the overlay loses its control-plane signaling. Without those control messages, edge devices stop receiving policy and route updates, so the fabric cannot adapt or reconfigure in response to changes. Existing tunnels may keep passing traffic, but the dynamic management and coordination that keeps the network aligned fail. That’s why loss of control-plane signaling best describes the typical failure mode when vSmart or vBond is down.