单项选择题 In an environment with STP disabled, which of the following is the MOST likely cause of the exponential increase in repeated packets transferred through the network?（）

单项选择题 Users are reporting problems connecting to servers in the remote company.com domain. The administrator suspects this to be a DNS problem. Which of the following commands would the administrator run to identify the DNS server of the remote company.com?（）

单项选择题 Which of the following commands is used to display other computers running on the network?（）