Implementing Cisco Enterprise Advanced Routing and Services (ENARSI) — Question 147

How does an MPLS Layer 3 VPN function?

Answer options

• A. multiple customer sites interconnect through service provider network to create secure tunnels between customer edge devices
• B. multiple customer sites interconnect through a service provider network using customer edge to provider edge connectivity
• C. set of sites interconnect privately over the Internet for security
• D. set of sites use multiprotocol BGP at the customer site for aggregation

Correct answer: B

Explanation

The correct answer is B, as it accurately describes how MPLS Layer 3 VPNs enable multiple customer sites to connect through a service provider's network with proper edge connectivity. Option A is incorrect because it emphasizes secure tunnels rather than the connectivity framework. Options C and D do not represent MPLS Layer 3 VPN functionality; C refers to a public Internet connection, and D incorrectly describes BGP's role in this context.