Cisco Certified Network Associate (CCNA) Practice Exam

What command is used to save the running configuration after making changes to a router's configuration?

1. #copy running-config startup-config

2. #save configuration

3. #write memory

4. #backup config

The correct answer is: #copy running-config startup-config

The command used to save the running configuration to the startup configuration on a Cisco router is 'copy running-config startup-config'. This command ensures that any changes made to the router's configuration during a session are retained after a reboot. When you enter this command, the router takes the current configurations that are active (the running configuration) and copies them to the startup configuration file, which is stored in non-volatile memory. This means that when the router restarts, it will use the saved configuration to boot up with the same settings that were in effect before the reboot. The other options provided do not achieve this purpose. For instance, while 'write memory' is a legacy command that also accomplishes saving the configuration, it is less commonly used in modern practice where 'copy running-config startup-config' is the preferred method. 'save configuration' and 'backup config' are not valid commands in Cisco IOS, and therefore, would not execute successfully.