Which command would you use to save the configuration on a Cisco router?

The command to save the configuration on a Cisco router is commonly used to ensure that the current running configuration, which is stored in RAM, is transferred to the startup configuration, which is stored in NVRAM. This process is essential because if the router is rebooted, it will lose any unsaved changes that exist only in the running configuration.

The command consists of two parts: "copy," which indicates the action of duplicating data from one source to another, and "running-config startup-config," which specifies the source (the current active configuration) and the destination (the saved configuration that will be loaded upon the next reboot). This approach effectively secures the latest configuration changes and guarantees that they are not lost during a restart.

While there are other commands that could also be associated with saving configurations, such as "write memory," which is an older way to achieve the same result, the command provided is the most direct and widely used in modern Cisco IOS. Other options, like "save config" and "store current-settings," do not correspond to valid Cisco commands for this purpose, hence why they are not considered correct.