单项选择题
What features set is most frequently used to prevent hackers from flooding a port with MAC- addresses？（）
A.BPDU Guard B.802.x C.Port Security D.Storm Control
单项选择题 ATT（Attached）bitneedstobesetinthelinkstatePDUsinanIS-ISlevel-1-2routertoindicatethattheyareapotentialexitpointoutofthearea.（）
单项选择题 Whatisthestatisticalreserve？（）
单项选择题 WhatisTCI？（）
