Implementing Cisco Enterprise Advanced Routing and Services (ENARSI) — Question 455

What is an advantage of MPLS Layer 3 VPN deployment?

Answer options

• A. Planning and modifications are required for the customer intranet before migrating to Layer 3 VPN.
• B. Scalable VPNs are created using connection-oriented, point-to-point, or multipoint overlay connections.
• C. QoS provides performance with policy and support for a best-effort service level in an MPLS VPN.
• D. Security is provided at the edge of the provider network through encryption.

Correct answer: C

Explanation

The correct answer is C because QoS (Quality of Service) is essential in MPLS Layer 3 VPNs to ensure that different types of traffic receive appropriate treatment, supporting performance and service levels. Option A is incorrect because it suggests unnecessary prior changes to the intranet, while B describes a characteristic of the VPNs but does not highlight an advantage. Option D is misleading as security in MPLS VPNs is typically managed differently, often relying on mechanisms other than just encryption.