Which command enters global configuration mode?

• A. configure terminal
• B. line vty
• C. interface range
• D. copy

Answer: (A)

Entering global configuration mode lets you change settings that affect the entire device. You usually start from privileged EXEC mode (the prompt ends with a #). The command to enter global configuration mode is configure terminal. After typing it, the prompt changes to (config) and you can configure system-wide options such as hostname, banner, enable secret, and domain-name. From this mode you can dive into specific sub-modes, like configuring interfaces or VTY lines, to apply targeted settings.

The other options move you directly to particular sub-modes or perform file operations, not to global configuration. For example, line vty opens the configuration for remote-access lines, interface range starts configuration for multiple interfaces, and copy is for transferring files, not configuring the device.