According to this figure, which of the following is the correct description of the IPv6 routing information calculated by the R4 router through IS-IS?

Which of the following statements about the freeway of LDP label retention is correct? (Multiple choice)

Traditional BGP4 can only manage IPv4 unicast routing information. In order to provide support for multiple network layer protocols, MP-BGP extends BGP-4.
MP-BGP uses address families to distinguish different network layer protocols. Which of the following address families are currently supported? (Multiple choice)

In the finishing work of the structured network troubleshooting process, which of the following are the documents that need to be handed over? (Multiple choice)

BFDLink state detection at the heart (millisecond) level can be achieved.