A.Route summarization is the process of summarizing routes with the same prefix into one route and then advertising only the summarized route to other areas.

B.OSPF supports two route summarization modes: ABR summarization and ASBR summarization.

C.Route summarization can reduce routing information, decrease the routing table size, and improve router performance.

D.Any router in OSPF can summarize routes.

A.By default, the routes learned from an IBGP peer will not be forwarded to other IBGP peers.

B.Only the routes learned from IGPs can be advertised to other BGP peers.

C.All the BGP routes learned from all BGP peer will be advertised to other BGP peers.

D.Only the optimal routes preferred by BGP can be advertised to other BGP peers.

A.The unit of this field is seconds. In a LSDB, the LS age of a LSA increases with time.

B.If the LS age of a LSA has reached the LSRefreshTime (30 minutes), the originator of this LSA needs to regenerate an instance of this LSA again.

C.If the LS age of a LSA has reached the LSRefreshTime (30 minutes), any router can regenerate an instance of this LSA again.

D.The unit of this field is seconds. In a LSDB, the LS age of a LSA decreases with time.

A.60s

B.20s

C.90s

D.75s