单项选择题
A.Loop guard only operates on interfaces that are considered point-to-point by the spanning tree.
B.Loop guard only operates on root ports.
C.Loop guard only operates on designated ports.
D.Loop guard only operates on edge ports.
单项选择题 WhywouldaroguehostthatisrunningaDHCPserveronacampusLANnetworkpresentasecurityrisk？（）
单项选择题 TheclassicSpanningTreeProtocol（802.1D1998）useswhichsequenceofvariablestodeterminethebestreceivedBPDU？（）
单项选择题 WhichofthesebestdescribestheactionstakenwhenaVTPmessageisreceivedonaswitchconfiguredwiththeVTPmode"transparent"？（）