单项选择题
Which of the addresses below is an example of a valid unicast address?（）
A.172.31.128.255./18 B.255.255.255.255 C.192.168.24.59/30 D.224.0.0.5 E.All of the above
单项选择题 Which one of the protocols below allows a router to respond to an ARP request destined to a remote host?（）
单项选择题 Which of the following processes, is used to find the hardware address of a LAN device?（）
多项选择题 Which of the following are actual varieties of network crosstalk?（）
