多项选择题
A.The port immediately transitions to the Forwarding state.
B.The switch generates a Topology Change Notification （TCN） BPDU.
C.The port immediately transitions to the err-disable state.
D.The port becomes a normal STP switch port.
单项选择题 WhatwilloccurwhenanonedgeswitchportthatisconfiguredforRapidSpanningTreedoesnotreceiveaBPDUfromitsneighborforthreeconsecutivehellotimeintervals？（）
单项选择题 WhichoptioncorrectlyidentifiestheCiscoIOSswitchingmethodsindescendingorderfromthefastestmethodtotheslowestmethod？（）
多项选择题 WhichthreestatementsaretrueoftheLinkAggregationControlProtocol（LACP）？（）