简答题 Which OSPF network type is ideal for partially meshed NBMA networks because it is easy to configure（requires no configuration of neighbor commands）， consumes only one IP subnet， and requires no designated router election？

问答题WhichOSPFfeatureallowsaroutertocontinuetoforwardpacketswhileundergoingspecific，well-knownfailureconditions？

问答题WhyareRegistermessagesneededinPIMSM？

问答题switchortport-securityviolation选择shutdown表示什么意思？

问答题Whatisthepurposeofanadministrativedistance？

问答题whatistheattributesthatarerequiredtobesenttoBGPneighbors？