MPLS and Routing Tables JN0-364 Practice Questions (Page 4)

Questions 16–20

1. 16application · medium

   You are examining the MPLS forwarding table on a router and see an entry that maps an incoming label to a next hop. You want to understand how the incoming label is mapped to the outgoing label and action. Which two components work together to accomplish this mapping?

   • AThe BGP table and the VRF, where the BGP table provides the VPN label and the VRF provides the next hop.
   • BThe LIB and the LFIB, where the LIB maps the incoming label to the LFIB for the outgoing label.
   • CThe ILM and the NHLFE, where the ILM maps the incoming label to an NHLFE that specifies the outgoing label and action.
   • DThe FIB and the RIB, where the FIB provides the outgoing label and the RIB provides the next-hop IP address.
   Reveal Solution Discussion Select an answer first
2. 17application · medium

   A service provider is deploying MPLS-TE in their network to optimize traffic flow. They need to understand how the label stack is used to support traffic engineering. Which statement correctly describes the role of the label stack in MPLS-TE?

   • AThe label stack can contain multiple labels, where the top label is used for the TE tunnel and the inner labels are used for the underlying service.
   • BThe label stack is only used for VPN services and cannot be used for traffic engineering.
   • CThe label stack is used to store the IP addresses of all routers in the TE path.
   • DThe label stack is limited to a single label, which is used for both the TE tunnel and the service.
   Reveal Solution Discussion Select an answer first
4. 18foundation · easy

   When PHP is enabled, what does the penultimate router do with the label?

   • AIt pops the label before forwarding the packet.
   • BIt leaves the label unchanged.
   • CIt swaps the label with a new one.
   • DIt pushes a new label onto the packet.
   Reveal Solution Discussion Select an answer first
5. 19foundation · easy

   What label operation does a transit router typically perform on a labeled packet as it forwards it along an LSP?

   • AReplace
   • BPop
   • CSwap
   • DPush
   Reveal Solution Discussion Select an answer first
6. 20expert · hard

   You are troubleshooting an MPLS network where the egress PE router is receiving packets with an unexpected label. You suspect that PHP is not working correctly. What should you check on the penultimate router to verify that PHP is functioning?

   • ACheck the routing table on the penultimate router for a route to the egress PE's loopback address.
   • BCheck the forwarding table on the penultimate router for a label entry that specifies a pop operation for the outgoing label.
   • CCheck the MPLS label stack on the egress PE to see if the outer label is present.
   • DCheck the LDP session status between the penultimate router and the egress PE.
   Reveal Solution Discussion Select an answer first