An engineer must build a VXLAN flood-and-learn network. The customer requires the solution to be based on the IETF documented practice in RFC 7348. The solution must use broadcast, unknown unicast, an

MVPN (Multicast VPN) is a solution for carrying multicast traffic over a VPN, not a specific multicast routing protocol that exclusively uses shared trees for BUM replication.

PIM sparse mode primarily builds shared trees but can switch to source-specific trees (SPT) once a source is known, which does not exclusively use shared trees for all BUM traffic as required.

PIM SSM (Source Specific Multicast) only builds source-specific trees, where receivers explicitly join a specific source and group, and does not use shared trees, failing to meet the requirement for BUM replication using only shared trees.

Bidirectional PIM (PIM-BiDir) is a multicast routing protocol that builds only shared trees, rooted at a Rendezvous Point (RP), for all multicast traffic. This characteristic makes it suitable for VXLAN flood-and-learn networks using BUM (Broadcast, Unknown Unicast, Multicast) replication, as it efficiently handles many-to-many traffic flows by consistently utilizing shared trees, aligning with the requirements for efficient and short BUM replication modes as per RFC 7348.