Refer to the exhibit. An architect must design an enterprise WAN that connects the headquarters with 22 branch offices. The number of remote sites is expected to triple in the next three years. The…

EIGRP Over the Top uses EIGRP as the overlay routing protocol and does not use MP-BGP to carry VPNv4 labels and VPN payload, failing the control plane requirement.

Multipoint GRE tunnels create an enterprise-owned overlay transport that is completely independent of and not controlled by the service provider, fulfilling the requirement that the transport layer remain under enterprise control. MP-BGP running over this GRE overlay carries VPNv4 labels and VPN payload as specified, while only CE loopback addresses are advertised into the SP network keeping internal topology hidden. Multipoint GRE also scales efficiently as the branch count triples, avoiding the point-to-point tunnel proliferation problem.

DMVPN per VRF uses GRE tunnels with NHRP and typically uses EIGRP or OSPF as the overlay routing protocol - it does not natively implement an MP-BGP VPNv4 control plane over the transport layer.

Point-to-point GRE per VRF does not scale for 22 branches growing to 66 or more because each new branch requires dedicated tunnel interfaces on all other routers, creating an unmanageable configuration burden.