单项选择题
A.IBGP updates exchange between trigger router and black hole router
B.EBGP updates exchange between trigger router and black hole router
C.OSPF updates exchange between trigger router and black hole router
D.ISIS updates exchange between trigger router and black hole router
多项选择题 WhichofthefollowingstatementsaboutMD5RoutingUpdatesauthenticationisvalid？（）
单项选择题 WhatistheimportanceofusingVirtualOutputQueuesoningressLineCardsinahigh-endrouter？（）
单项选择题 InAnyTransportoverMPLS（AtoM）Controlwordisanoptional4-bytefieldusedinthepseudowirepacket.ThecontrolwordcarriesgenericandLayer2payload-specificinformationtoemulateL2packetscorrectly.Inpseudowirepacket，whereisthisControlWordinserted？（）