多项选择题
Which characteristics are representative of a link-state routing protocol? （）
A.provides common view of entire topology B.exchanges routing tables with neighbors C.calculates shortest path D.utilizes event-triggered updates E.utilizes frequent periodic updates
单项选择题 一个A类地址，其子网掩码是255.255.240.0，有多少位被用来划分子网？（）
多项选择题 Which two commands correctly verify whether port security has been configured on port FastEthernet 0/12 on a switch?（）
多项选择题 下面接口为物理接口的有（）。
