单项选择题 When making changes to a server, which of the following is the BEST way to troubleshoot a problem?（）

多项选择题 Which of the following are examples of physical security measures?（）

单项选择题 A new server was installed. Most clients are located in the same subnet as the server and can successfully access the server. Clients located on different subnets have been unable to access the server, but have no trouble accessing other servers on their subnet. Which of the following is the reason that these clients are unable to access the server?（）