单项选择题
A. spanning-tree misconfiguration
B. speed mismatch configuration
C. cabling problem
D. configuration problem
单项选择题 WhichtypeofdomainsisinterconnectedusingMulticastSourceDiscoveryProtocol？（）
多项选择题 An802.1Qtrunkisnotcomingupbetweentwoswitches.Theportsonbothswitchesareconfiguredas"switchportmodedesirable."Assumingthatthereisnophysicalissue，choosetwopossiblecauses.（）
单项选择题 YoureplacedyourLayer3switch，whichisthedefaultgatewayoftheendusers.Manyuserscannotaccessanythingnow，includingemail，Internet，andotherapplications，althoughotherusersdonothaveanyissues.Alloftheapplicationsarehostedinanoutsourceddatacenter.Inordertofixtheproblem，whichoneoftheseactionsshouldyoutake？（）
