Deploying Cisco Service Provider Edge Technologies (SPEDGE, legacy) — Question 7

When implementing MPLS Layer 3 VPNs with customers running OSPF as the CE-PE routing protocol, which situation will require a sham link to be implemented in the MPLS backbone?

Answer options

• A. to connect customer sites in different OSPF areas
• B. to connect customer sites in the same OSPF area
• C. to prevent OSPF routing loops when a customer site has redundant CE-PE connections D.

Correct answer: C

Explanation

The correct answer is C because a sham link is specifically designed to prevent routing loops in scenarios where a customer site has redundant connections to the provider edge. Options A and B do not involve issues related to routing loops, and option D is incomplete and does not provide a valid scenario.