Cisco Certified Network Associate (CCNA) Practice Exam

After making configuration changes on a router, what is the command to save the running configuration?

1. copy start run

2. copy run start

3. write memory

4. save config

The correct answer is: copy run start

The command to save the running configuration on a router is "copy running-config startup-config," which is often abbreviated as "copy run start." This command transfers the current active configuration (the running configuration) in RAM to the startup configuration stored in the router's non-volatile memory (NVRAM). By doing this, the configuration will persist even after the device is rebooted, ensuring that all settings remain intact. Using this command is crucial after making any configuration changes; otherwise, if the router is restarted or loses power, all unsaved changes will be lost. This command is foundational in managing router configurations effectively and ensures that any settings you have applied will be reloaded upon the next boot of the router. Other options involve incorrect command formats or concepts that don't apply to saving configurations. For instance, "copy start run" is not a valid command sequence as it suggests copying from the startup configuration to the running configuration, which is not the intention when trying to save. "Write memory" is an alternative command to save the configuration but is less commonly used nowadays compared to the copy command. "Save config" is not a recognized command in Cisco IOS for saving the configuration and would result in an error if attempted.