You are configuring a BGP signaled Layer 2 VPN across your MPLS enabled core network. In this scenario, which statement is correct?

In a BGP-signaled Layer 2 VPN (also known as a Kompella L2VPN), each customer site connected to a PE router must be assigned a site identifier. This identifier must be unique for each site within a particular Layer 2 VPN routing instance. The site identifier, along with the route distinguisher and label block, is used to create a unique Layer 2 VPN Network Layer Reachability Information (NLRI) prefix that BGP advertises to other PE routers. This mechanism allows the remote PE routers to identify the specific customer attachment circuit for which the pseudowire is being established.

B. This type of VPN supports multiple Layer 2 encapsulations, including Frame Relay, ATM, and PPP, in addition to Ethernet.

C. This type of VPN uses the l2vpn address family (AFI 25, SAFI 128), not the inet-vpn NLRI, which is used for Layer 3 VPNs.

D. The route distinguisher (RD) is used to make routes unique and is typically configured to be unique per routing instance on each PE router.

1. Juniper Networks TechLibrary

"Layer 2 VPNs and VPLS Feature Guide for Routing Devices": In the section "Configuring BGP Signaling for Layer 2 VPNs

" the documentation states

"For each routing instance

you must configure a unique site identifier for each site." This directly confirms the requirement for a unique site number.

2. Juniper Networks TechLibrary

"Junos OS VPNs Library for Routing Devices": Under the "Layer 2 VPNs User Guide

" the section "Understanding BGP Signaling in Layer 2 VPNs" describes the NLRI format. It specifies that the NLRI is composed of the Route Distinguisher (RD)

Site ID

Label Offset

and Label Base

highlighting the fundamental role of the unique Site ID.

3. Juniper Networks TechLibrary

"Layer 2 VPNs and VPLS Feature Guide for Routing Devices": The section "Layer 2 VPNs Encapsulation" lists supported encapsulation types

including ethernet

ethernet-vlan

frame-relay

and atm-aal5

which explicitly refutes the claim that only Ethernet is supported.