Cisco Certified Network Associate (CCNA) Practice Exam

After making configuration changes, what command should be used to save the running configuration?

1. #copy run start

2. #write memory

3. #save config

4. #copy config run

The correct answer is: #copy run start

The command to save the running configuration to the startup configuration is "copy run start." This command effectively copies the current configuration that is actively running in the router's memory (running-config) to the configuration stored in non-volatile memory (startup-config). This action is critical because any changes made in the running configuration are lost if the device is restarted or loses power. By saving the running configuration, these changes are preserved and will be applied the next time the device boots up. In network devices, the running configuration exists only in RAM and is vulnerable to being lost during a reboot. The startup configuration, on the other hand, is stored in NVRAM and is retained through reboots. Therefore, using this command ensures that configuration changes are not lost and allows for a consistent network state across reboots. The other commands don't accurately perform the intended action of saving the configuration: - The command "write memory" is a legacy command that achieves the same result as "copy run start," but it is not used universally across all Cisco devices, especially newer ones. - "save config" is not a recognized command in Cisco IOS. - "copy config run" is also incorrect because it does not specify the correct source and destination, potentially leading to