单项选择题 A new company has been given one public IP address. The company employs 200 users requiring Internet access from the headquarters. Which of the following can be implemented to provide Internet access for all the employees?（）

单项选择题 An administrator is unable to ping a workstation. Which of the following tools would BEST help toresolve the issue?（）

多项选择题 Which of the following features would BEST be used to optimize real-time voice and video chat?（）(Select TWO)