单项选择题
A. [edit interfaces ge-0/0/9 unit 0] user@router# set family inet address /24
B. [edit interfaces ge-0/0/9 unit 0] user@router# set family inet secondary-address /24
C. [edit interfaces ge-0/0/9 unit 0] user@router# set family inet address /24 secondary
D. [edit interfaces ge-0/0/9 unit 0] user@router# set family inet address-secondary /24
单项选择题 An administrator is unable to ping any address on the 10.0.19.0/24 subnet. To identify the problem, the administrator uses the command shown in the exhibit. Which step should be taken to solve the problem?（）
单项选择题 You have been asked to use a 23-bit network mask to segment the network block 209.18.12.0.How many usable host addresses will there be per subnet?（）
单项选择题 You have been allocated a /22 network.How many usable hosts are available?（）
