300-510 SPRI: Implementing Cisco Service Provider Advanced Routing SolutionsDemo

By Cisco · Question Mode

QuestionQ251

Unicast Routing

Question Image

Refer to the exhibit. ISP_1 uses eBGP to connect to every client. Within the ISP_1 network, LDP is used with OSPF and IS-IS. Client_A and Client_B are in the same VRF_VoD. After a software upgrade on every router in the ISP_1 network, Client_A has lost connectivity to Client_C. A network engineer must troubleshoot connectivity from R1 to R4 through ISP_1. Following initial checks, the engineer verified that all routes are installed correctly. Which two tasks must the engineer complete to resolve the issue?

Choose two
  • A Configure next-hop-unchanged under the BGP configuration on R31.
  • B Configure ip cef under the global configuration on R31.
  • C Configure mpls label implicit-null under the global configuration on R31.
  • D Configure next-hop-self under the BGP configuration on R42.
  • E Configure send-label under the BGP configuration on R42.
Explanation

BGP labeled-unicast forwarding requires the original reachable BGP next hop to be retained so that the LDP transport LSP can reach it, and it requires BGP to advertise a label bound to the route. next-hop-unchanged on R31 preserves the remote next-hop attribute; send-label on R42 associates and advertises the BGP label for the prefix. The displayed label bindings to next hop 33.33.10.1 require both behaviors for end-to-end MPLS forwarding.

Learn more

Community Discussion

No comments yet. Be the first to start the discussion!