Which DCI technology utilizes a "flood and learn" technique to populate the Layer2 forwarding table?

LISP uses a map-request/map-reply control plane to resolve endpoint identifiers to routing locators, not flood-and-learn.

OTV uses a control-plane-based MAC learning mechanism over an overlay, avoiding flooding across the DCI link.

VPLS emulates a full-mesh Ethernet LAN service by flooding unknown unicast, broadcast, and multicast frames to all pseudowires in the VPLS instance. As frames arrive, the source MAC addresses are learned and associated with the incoming pseudowire, populating the Layer 2 forwarding table dynamically - this is the classic flood-and-learn behavior inherited from standard Ethernet bridging.

EVPN distributes MAC and IP reachability information via BGP control plane advertisements, eliminating the need for data-plane flooding to learn addresses.