The EVPN control plane, which utilizes Multiprotocol BGP (MP-BGP), is responsible for learning and distributing endpoint (host) reachability information across the network. When a leaf device learns the MAC address of a locally connected host, it advertises this information to other VTEPs using an EVPN Type 2 (MAC/IP Advertisement) route. This same route type can also carry the host's IP address, which is learned via mechanisms like ARP snooping. This control plane learning and distribution of MAC and IP addresses eliminates the need for traditional data-plane flood-and-learn mechanisms and enables more efficient forwarding and features like ARP suppression.

A. The control plane encapsulates the traffic.

This is incorrect. Encapsulation of Ethernet frames into VXLAN packets is a data plane function performed by the VTEP's forwarding hardware.

D. The control plane rewrites the destination MAC address of the packet.

This is incorrect. Packet header modification, such as rewriting a MAC address for routing, is a data plane forwarding operation.

1. Juniper Networks TechLibrary, "Understanding EVPN with VXLAN Data Plane Encapsulation": In the "Control Plane: BGP" section, it states, "The control plane is responsible for MAC address learning and advertising... EVPN enables the control plane to learn and advertise not only the MAC addresses of the end devices, but also their IP addresses." This directly supports options B and C. The document also clarifies that VXLAN is the data plane encapsulation, which refutes option A.

2. Juniper Networks TechLibrary, "EVPN Type 2 Routes: MAC/IP Advertisement Route": This document specifies that the Type 2 route "advertises the MAC addresses of the hosts that are connected to a PE device... This route type can also optionally carry the IP address associated with the MAC address." This confirms that learning and advertising both MAC and IP addresses are functions of the EVPN control plane.

3. Juniper Networks Day One+ Guide, "Data Center Deployment with EVPN/VXLAN": In Chapter 2, "EVPN/VXLAN Fundamentals," the guide distinguishes between the control plane and data plane. It explains, "The control plane is responsible for exchanging reachability information between VTEPs... The data plane is responsible for encapsulating and decapsulating traffic." This clearly separates the control plane's role (learning/advertising) from the data plane's role (encapsulation, rewriting), refuting options A and D.