单项选择题
Spanning Tree Protocol calculates path cost based on which of these？（）
A.interface bandwidth B.interface delay C.interface bandwidth and delay D.hop count E.bridge priority
问答题 简述组播的sparse和dense的区别。
单项选择题 Whichstandardsupportsmultipleinstancesofspanningtree？（）
多项选择题 LoopguardandUniDirectionalLinkDetectionbothprotectagainstLayer2STPloops.InwhichtwowaysdoesloopguarddifferfromUDLDinloopdetectionandprevention？（）
