单项选择题
Which of these correctly identifies a difference between the way BPDUs are handled by 802.1w and 802.1D？（）
A.802.1D bridges do not relay BPDUs. B.802.1w bridges do not relay BPDUs. C.802.1D bridges only relay BPDUs received from the root. D.802.1w bridges only relay BPDUs received from the root.
问答题 R1，R2，R3 are all in same ospf area， there is a virtual link between R1 and R3. Pls answer： Are the hello packets exchanged between the virtual link？
多项选择题 UnderwhichtwocircumstanceswouldanRSTPbridgeflushitsCAMtable？（）
单项选择题 WhydoesRSTPhaveabetterconvergencetimethan802.1D？（）
