单项选择题 WhichofthefollowingensurestheMOSTsecureaccesstoaserverroom？（）

单项选择题 WhichofthefollowingisanexampleofaprivateIPaddress？（）

单项选择题 Users have reported that they cannot access certain Internet sites. An administrator wants to test that the sites are properly resolving to an IP address. Which of the following tools would allow the administrator to test name resolution?（）