Command
Copy Running-config Startup-config
Use
This command lets you save your running configuration to the router’s startup configuration (NVRAM) so it will survive a reload.
Syntax
Router#copy running-config startup-config
Example
In the below example R1’s startup configuration is saved.
R1#copy run start Destination filename [startup-config]? Building configuration… [OK] R1#
“so it will survive a reload.” What does this mean?
It means that if your device reboots, the changes that you have made to the startup configuration will not be lost, since the startup configuration has been overwritten with the currently running configuration once this command “copy running-config startup-config” is executed.
When you do the reload without saving the running-config to startup-config the running configuration will be wiped out from RAM