A public-works fabric must deliver broadcast, unknown unicast, and multicast (BUM) frames to other VTEPs in a VNI. What data-plane behavior is required?
Select an answer to reveal the explanation.
Short Explanation
BUM is the city megaphone—more than one listener needs a copy. VXLAN either blasts via underlay multicast or the ingress leaf photocopies the frame to each interested VTEP (head-end replication). One silent unicast to a random leaf won’t wake the whole VNI.
Full Explanation
Multi-destination overlay traffic must reach all VTEPs that participate in the VNI. Classic designs use underlay multicast groups; many modern EVPN-VXLAN fabrics use ingress replication (head-end replication) of BUM to remote VTEP lists. Dropping BUM at the ingress leaf breaks ARP/ND and unknown-unicast learning behaviors. Understanding which replication mode the municipal fabric uses is essential for capacity and troubleshooting.