单项选择题 A router that takes the workstations internal IP address and changes it to another IP address whenit sends the data outside of the network is an example of which of the following?（）

单项选择题 Which of the following protocols is commonly used for VoIP technology?（）

单项选择题 An administrator is experiencing availability issues on a Linux server. The administrator decides tocheck the server for an IP address conflict on the server. Which of the following commands should the administrator use?（）