单项选择题 What are the usable hosts on the .128.0/19 network?（）

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

单项选择题 You have been assigned the /24 network and need to segment it into at least 60 subnets.Which network mask meets this requirement?（）