单项选择题 Which two statements are true of a network mask?（）

单项选择题 Which user authenticaton method is supported by the Junos OS as the last resort alternative?（）

单项选择题 You must segement your internal 192.168.1.0/24 network into a minimun of 12 subnet, each containing a minimun of 12 hosts. Which network mask do you use?（）