单项选择题
Which spanning-tree command would cause a PortFast-enabled interface to lose its PortFast-operational status and disable BPDU filtering if it receives BPDUs？（）
A.spanning-tree guard root B.spanning-tree portfast bpduguard default C.spanning-tree bpduguard enable D.spanning-tree bpdufilter enable E.spanning-tree portfast bpdufilter default
单项选择题 Whichofthefollowingconditionsguaranteesthatabroadcaststormcannotoccur？（）
单项选择题 WhichstatementistrueregardingthePortAggregationProtocol？（）
单项选择题 WhichcommandalonewilldisabletrunkingonaLayer2switchport？（）
