单项选择题 An administrator is trying to isolate the location of a persistent connectivity problem caused by a faulty NIC. Which of the following diagrams would assist the technician in finding the machine that is causing the problem?（）

多项选择题 Which of the following ports are used by default for web servers? （）(Select TWO)

单项选择题 A technician needs to troubleshoot connectivity between two devices located on the same network. Which of the following BEST describes the type of protocol being used?（）