Refertothe exhibit.The networkshownintheexhibitisrunningtheRIPv2routingprotocol.Thenetworkhasconverged，andtheroutersinthisnetworkarefunctioningproperly.TheFastEthernet0/0interfaceonR1goesdown.Inwhichtwowayswilltheroutersinthisnetworkrespondtothischange？（）
A.R1willsendLSAstoR2andR3informingthemofthischange，andthenallrouterswillsendperiodicupdatesatanincreasedrateuntilthenetworkagainconverges.
B.Becauseofthesplit-horizonrule，routerR2willbepreventedfromsendingerroneousinformationtoR1aboutconnectivitytothe192.168.1.0network.
C.WhenrouterR2learnsfromR1thatthelinktothe192.168.1.0networkhasbeenlost，R2willrespondbysendingaroutebacktoR1withaninfinitemetrictothenetwork.
D.RoutersR2andR3marktherouteasinaccessibleandwillnotacceptanyfurtherroutingupdatesfromR1untiltheirhold-downtimersexpire.
E.Allrouterswillreferencetheirtopologydatabasetodetermineifanybackuproutestothe192.168.1.0networkareknown.
正确答案：参考B, C
