Your customer requires a Layer 2 VPN service (draft-kompella-mpls-l2vpn). You are asked to describe the
operational requirements on the PE router supporting this service.
Which two statements are true in this scenario? (Choose two.)
A.
The ingress PE router associates multiple MPLS labels with the corresponding traffic flows.
B.
The ingress PE router for a traffic flow maintains the data-link connection identifier.
C.
The ingress PE router for a traffic flow removes the data-link connection identifier.
D.
The ingress PE router associates a single MPLS label with the corresponding traffic flows.
Explanation:
A: When a packet arrives at a PE from a CE in a Layer 2 VPN, the Layer 2 address of the packet identifies to
which remote attachment circuit (and thus remote CE) the packet is destined. The procedure installs a route
that maps the Layer 2 address to a tunnel (which identifies the PE to which the destination CE is attached) and
a VPN label (which identifies the destination AC). If the egress PE is the same as the ingress PE, no tunnel or
VPN label is needed.
C: In case of IP-only Layer 2 interworking, the Layer 2 header is completely stripped off till the IP header.
https://tools.ietf.org/html/draft-kompella-l2vpn-l2vpn-10