In an EVPN-VXLAN fabric, Broadcast, Unknown Unicast, and Multicast (BUM) traffic must be replicated and forwarded to all relevant Virtual Tunnel Endpoints (VTEPs) within a given Virtual Network Identifier (VNI). There are two primary methods to achieve this.

1. Ingress Replication (IR): The ingress VTEP, upon receiving a BUM frame, replicates the packet and sends a separate unicast VXLAN-encapsulated copy to every other VTEP participating in the same VNI. The list of remote VTEPs is learned via the BGP EVPN control plane using Type-3 (Inclusive Multicast Ethernet Tag) routes.

2. Underlay Replication (Multicast): The ingress VTEP sends a single copy of the BUM packet encapsulated in a VXLAN packet destined for a multicast group address. The IP underlay network, configured with a multicast routing protocol like PIM, handles the replication and forwarding of this packet to all VTEPs that have joined the multicast group for that VNI.

A. Use static routes: Static routes are used for Layer 3 unicast IP forwarding and are not a mechanism for handling multi-destination Layer 2 BUM traffic in an EVPN fabric.

B. Use BGP neighborship: BGP is the control plane protocol used to exchange EVPN route information, which enables BUM forwarding mechanisms like ingress replication, but it is not the data plane forwarding method itself.

1. Juniper Networks TechLibrary, "Understanding EVPN with VXLAN Data Plane Encapsulation": This document explicitly outlines the methods for BUM traffic handling. In the "BUM Traffic Handling" section, it states, "To handle BUM traffic, VTEPs can use ingress replication or PIM-based multicast in the underlay." This directly supports both ingress replication (C) and underlay replication (D).

2. Juniper Networks TechLibrary, "EVPN-VXLAN Multicast": This guide details the use of PIM in the underlay. The overview section explains, "You can configure Protocol Independent Multicast (PIM) in an Ethernet VPN-Virtual Extensible LAN (EVPN-VXLAN) fabric to enable multicast traffic to be forwarded efficiently through the fabric." This validates underlay replication (D).

3. Juniper Networks TechLibrary, "Example: Configuring EVPN-VXLAN with Ingress Replication": This configuration example demonstrates the setup for ingress replication, confirming it as a standard method. The "Overview" section states, "This example shows how to configure an EVPN-VXLAN fabric where ingress replication is used to forward BUM traffic." This validates ingress replication (C).

4. RFC 7432: BGP MPLS-Based Ethernet VPN: This foundational IETF standard describes the mechanisms. Section 8.3, "Inclusive Multicast Ethernet Tag Route," details the control plane signaling used to build the flood list for ingress replication. Section 11, "P-Tunnel Types for Inclusive Multicast," describes using underlay multicast (e.g., PIM-SM) for BUM traffic.