单项选择题 An administrator wants to test the network MTU. Which of the following commands allows differentsize packets to be sent?（）

单项选择题 An administrator suspects that an incorrect POTS line is carrying the DSL signal. Which of thefollowing will help diagnose this issue?（）

单项选择题 An administrator receives reports from users in an office that their 802.11g wireless connectivity has been problematic since the installation of the new wireless phone system. At which of the following frequencies are both systems operating at to cause this issue?（）