Which of the following statements about EVPN Layer-3 services that utilize the interface-ful model is TRUE?

In the EVPN Layer-3 interface-ful model, each subnet is configured as a separate VPLS service with an associated Integrated Routing and Bridging (IRB) interface within a VPRN. To handle inter-subnet (routed) traffic between different PEs, a special VPLS instance known as the Supplementary Broadcast Domain (SBD) is used. The SBD acts as a transport VPLS that interconnects all the IRB interfaces belonging to the same VPRN service across the participating PEs. When a packet needs to be routed from one subnet to another on a remote PE, it is forwarded over the SBD tunnels to the IRB interface on the destination PE.

A. EVPN MAC/IP routes (Route Type 2) advertise host-specific information (MAC and IP addresses), not the IP prefixes of entire subnets. Subnet prefixes are advertised using EVPN IP Prefix routes (Route Type 5).

C. Intra-subnet traffic is Layer 2 bridged traffic that remains within the VPLS service designated for that specific subnet. The SBD is exclusively used for carrying inter-subnet (Layer 3 routed) traffic between PEs.

D. MAC/IP route information is used to populate the Forwarding Database (FDB) for MAC learning and the ARP/ND cache on remote PEs for host resolution. The VPRN routing table is populated by IP Prefix routes (Route Type 5).

1. Nokia 7750 SR OS Services Architecture Guide, Release 21.10.R1, Section: "EVPN for VXLAN in a VPRN service", Subsection: "Interface-ful IP-VRF-to-VLAN model".

This section explicitly states: "The SBD is a VPLS service that connects all the IRB interfaces of the VPRN service. When a PE needs to send a routed packet to a remote PE, it sends it through the SBD." This directly supports option B.

The guide also clarifies: "Each subnet is associated with a VPLS service where the Layer 2 traffic is bridged." This refutes option C, as intra-subnet traffic is handled by the subnet's own VPLS, not the SBD.

Regarding route types, it specifies: "The PE also advertises the IRB subnet using an EVPN IP Prefix Route." This refutes option A. It also explains that MAC/IP routes are for the IRB's own MAC/IP, which populates the FDB/ARP cache, refuting option D.