City network staff are labeling the new NSX-T fabric and debate which layer is overlay versus underlay. Which identification is correct?
Select an answer to reveal the explanation.
Short Explanation
Think of overlay as the named bus routes the VMs ride and underlay as the actual pavement those buses roll on. Encapsulated packets travel the physical IP fabric; the VMs still see their logical segments. Cabling, vSAN, and Carbon Black are not those two SDN layers.
Full Explanation
In NSX-T, the overlay is the logical network presented to workloads—segments and gateways. The underlay is the physical routed IP network that transports Geneve-encapsulated packets between tunnel endpoints. Swapping those labels, or mapping overlay/underlay to vSAN, HA, Carbon Black, or Workspace ONE, misses the SDN building-block definition.