Refer to the exhibit. An engineer is troubleshooting connectivity issues on the MPLS core network. A customer connected through R4 cannot reach the OSPF domain on R5. While checking the routing…

Question

Exhibit

Options

• AEnable OSPF peering and configure route redistribution between routers R4 and R1.
• BEnable route filtering between routers R1 and R3.
• CEnable MP-BGP peering on routers R1, R3, R4, and R5.
• DEnable OSPF on the Area-0 routers and configure MP-BGP between routers R1 and R3.

• A
  80% (20)
• B
  4% (1)
• C
  12% (3)
• D
  4% (1)

Explanation

In an MPLS VPN or interconnected network, if R1 cannot see routes from R3 and R5, route redistribution between the routing domains is missing. R4 (a customer router) needs to reach R5's OSPF domain, but there is no routing protocol adjacency or redistribution configured between the customer-facing routers (R4 and R1) and the OSPF domain where R5 resides. Enabling OSPF peering between R4 and R1 and then redistributing routes between OSPF and whatever protocol R1 uses allows R4 to learn R5's prefixes. Option B (enable route filtering) would restrict routes further, worsening the problem. Option C (MP-BGP on R1, R3, R4, R5) might work but is overly complex and not targeted at the direct customer-to-OSPF domain connectivity issue. Option D is a partial version of Option C but still doesn't address the direct R4-to-R5 path without the OSPF adjacency and redistribution at the edge.

No community discussion yet for this question.