During a city DR test, BGP EVPN sessions flap while some existing VXLAN data-plane flows briefly continue. What operational nuance is most accurate at concept level?
Select an answer to reveal the explanation.
Short Explanation
Think of the control plane as the dispatcher and the data plane as cars already on the road—traffic already queued can keep moving for a bit even if the radio cuts out. New learning and clean withdrawals still need the dispatcher back. That is nuance, not a claim that BGP keepalives ride inside every tenant frame.
Full Explanation
Overlay forwarding hardware/software tables can continue forwarding known flows for some period after EVPN control-plane disruption, depending on timers, graceful restart behaviors, and implementation. That does not mean control-plane health is optional: advertisements, MAC moves, withdrawals, and new learning require EVPN/BGP recovery. VXLAN tenant packets do not embed BGP keepalives, and fabrics do not safely rely on endless flooding as a substitute for state. DR testing should validate both residual forwarding behavior and control-plane restoration.