Chapter 13

1. What would you configure on the PE routers if you wanted to be able to see the LSRs in the output of the traceroute command from the PE routers, but not the customers performing the traceroute from the CE routers?
A1: Answer: In that case, you would configure no mpls ip propagate-ttl forwarded.
2. When is the MPLS TTL not copied to the IP TTL when disposing of the labels? Why?
A2: Answer: When MPLS TTL > IP TTL, the MPLS TTL value is not copied into the IP header. This rule prevents packets from looping forever when the command no mpls ip propagate-ttl (forwarded) is configured on the ingress PE routers/LSRs.
3. What kind of packets are sent when you traceroute in Cisco IOS?
A3: Answer: The packets that are sent when tracerouting ...

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