单项选择题 WhichofthesestatementsaboutPIMjoinmessagesinclassicPIM-SMiscorrect？（）
单项选择题 InPIM-SMwhatcontrolplanesignalingmustamulticastsourceperformbeforeitbeginstosendmulticasttraffictoagroup？（）
单项选择题 TworoutersconfiguredtorunBGPhavebeenconnectedtoafirewall，oneontheinsideinterfaceandoneontheoutsideinterface.BGPhasbeenconfiguredsothetworoutersshouldpeer，includingthecorrectBGPsessionendpointaddressesandthecorrectBGPsessionhop-countlimit（EBGPmultihop）.WhatisagoodfirsttesttoseeifBGPwillworkacrossthefirewall？（）