单项选择题
A technician needs to manage a switch by using the management port on the back of the switch.Which of the following cables would the technician use?（）
A.Straight B.Console C.Crossover D.Loopback
单项选择题 Which of the following would MOST likely be used to punch down LAN cables before connecting them to the main switch?（）
单项选择题 In which of the following layers of the OSI model does the TCP protocol operate?（）
单项选择题 Which of the following ports does POP3 services use, by default?（）
