How can shared services in an MPLS Layer 3 VPN provide Internet access to the customers of a central service provider?

Question

Options

• AThe CE router can establish a BGP peering to a PE router and use the PE device to reach the
• BRoute distinguishes are used to identify the routes that CEs can use to reach the Internet
• CThe customer VRF uses route targets to import and export routes to and from a shared services
• DStatic routes on CE routers allow route leakage from a PE global routing table

• A
  2% (1)
• B
  12% (5)
• C
  80% (33)
• D
  5% (2)

Explanation

In MPLS L3 VPN, Route Targets (RTs) control which routes are imported and exported between VRFs. A shared services VRF (containing Internet routes) can be configured with specific export RTs, and customer VRFs import those RTs to gain access to the shared routes (and vice versa). This 'hub-and-spoke' or 'extranet' VRF design is the standard MPLS mechanism for shared Internet access. Option A is incorrect because CE-to-PE BGP peering alone does not grant Internet access without proper VRF route leaking. Option B is wrong because route distinguishers (RDs) make routes unique in the BGP table but do not control route distribution. Option D is incorrect because static routes on CE routers do not enable leaking from the PE global table.

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