In an EVPN/VXLAN fabric a MAC-VRF (also called an EVPN Instance) is created per bridge domain or Layer-2 segment. The exhibit shows two distinct bridge domains (BD-10 and BD-20) that belong to the same tenant. Because each BD requires its own EVPN control-plane context, exactly two MAC-VRFs are instantiated across all participating PEs. The number of PEs or the presence of an IP-VRF for inter-subnet routing does not change this fact—only the number of bridge domains determines the number of MAC-VRFs. Therefore, the correct count is 2.

A. 1 – Only one MAC-VRF would exist if there were a single bridge domain; the exhibit shows two.

C. 3 – A third context would be an IP-VRF, not a MAC-VRF.

D. 4 – Would require four separate bridge domains, which are not present in the exhibit.

1. Nokia SR OS Service Configuration Guide — EVPN, R22.5, Section 5.1 “MAC-VRF and IP-VRF Constructs”, pp. 77-78.

2. Nokia SR OS Layer 2/EVPN Services Guide, R22.5, Figure 5-2 “Tenant with two bridge domains”, p. 84.

3. IETF RFC 7432 “BGP MPLS-Based Ethernet VPN”, Section 2.1, para 3 (“A MAC-VRF is instantiated for every bridge domain”).

4. Nokia VSP Fabric Technical Configuration Guide 9.0, Chapter “EVPN-VXLAN”, p. 112, bullets under “Designing Bridge Domains and MAC-VRFs.”