单项选择题
On which types of network will OSPF elect a backup designated router（）。
A.point-to-point and multiaccess B.point-to-multipoint and multiaccess C.point-to-point and point-to-multipoint D.nonbroadcast and broadcast multipoint E.nonbroadcast and broadcast multiaccess
单项选择题 Which type of attack is characterized by flood of packet that requesing a TCP connection to a server?（）
单项选择题 Which item represents the standard IPACL？（）
单项选择题 What is the default routing update period for RIPv2?（）
