Drag and Drop Question Drag and drop the MPLS VPN concepts from the left onto the correct descriptions on the right.

Question

Explanation

This question tests knowledge of core MPLS Layer 3 VPN architecture components and their roles in separating and forwarding customer traffic across a provider network. Candidates must correctly match each term to its functional description.

Approach. Map each MPLS VPN term to its role: CE (Customer Edge) is the customer router that peers with the provider; PE (Provider Edge) is the provider router that maintains per-customer VRFs and applies MPLS labels; P (Provider core) router forwards labeled packets without VRF awareness; VRF (Virtual Routing and Forwarding) is the per-customer routing table instance on the PE; Route Distinguisher (RD) is a 64-bit value prepended to IPv4 prefixes to create unique VPNv4 routes; Route Target (RT) is a BGP extended community that controls which VRFs import or export routes; MP-BGP (Multiprotocol BGP) is the control-plane protocol used between PE routers to exchange VPNv4 prefixes. The inner MPLS label identifies the destination VRF/interface on the egress PE, while the outer label drives the packet across the provider core.

Concept tested. MPLS Layer 3 VPN architecture - roles of CE, PE, P routers; VRF instances; Route Distinguishers vs. Route Targets; MP-BGP as the VPNv4 control plane; and dual-label stack operation (transport label + VPN label).

Reference. Cisco CCNP ENCOR (350-401) - MPLS and VPN Technologies; RFC 4364 (BGP/MPLS IP VPNs)

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