单项选择题
A.one global STP instance for all VLANs
B.one STP instance for each VLAN
C.one STP instance per set of VLANs
D.one STP instance per set of bridges
单项选择题 TworoutersconfiguredtorunBGPhavebeenconnectedtoafirewall，oneontheinsideinterfaceandone ontheoutsideinterface.BGPhasbeenconfiguredsothetworoutersshouldpeer，includingthecorrectBGPsessionendpointaddressesandthecorrectBGPsessionhop-countlimitEBGPmultihop.WhatisagoodfirsttesttoseeifBGPwillworkacrossthefirewall？（）
多项选择题 Choosetwocommandsthatarerequiredtoenablemulticastonarouter，whenitisknownthatthereceiversuseaspecificfunctionalityofIGMPv3.（）
单项选择题 WhatisalsocalledType0authenticationinOSPFonCiscoRouters？（）