单项选择题 Which of the following monitors a server to see which protocols might be in use?（）

单项选择题 A client is having problems connecting remotely after replacing a router. An administrator has just created an action plan. Which of the following is the NEXT step the administrator should perform to resolve this issue?（）

单项选择题 For security reasons a network technician wants to install a Linux based email server, Microsoft web services, and directory services on different servers. Which of the following technologies would be BEST to reduce hard ware costs?（）