Cisco Certified Network Associate (CCNA) Practice Exam

Which command is used to copy the running configuration to the startup configuration on a Cisco router?

1. copy run start

2. show ip route

3. exit

4. clear ip cache

The correct answer is: copy run start

The command used to copy the running configuration to the startup configuration on a Cisco router is "copy run start." This command is essential for preserving the current configuration of a router, allowing it to be retained even after a reboot or power loss. The running configuration reflects the current operational settings and changes made to the router, while the startup configuration is what the router loads when it powers on. When you enter this command, the router takes the configurations that are currently in memory (running configuration) and saves them to the non-volatile memory (NVRAM), where the startup configuration resides. This ensures that any changes made during the current session will be available the next time the router is powered on or rebooted. The other options do not relate to saving configurations. For instance, "show ip route" is a command used to display the current routing table, providing insights into how the router is making routing decisions but does not affect saved configurations. "Exit" is simply a command used to exit the current configuration mode or session without any impact on the router's configurations. "Clear ip cache" is used for clearing the ARP cache specifically, which can affect IP address resolutions but does not involve saving configurations.