Backing Up and Restoring the Cisco IOS
Before you upgrade or restore a Cisco IOS, you really should copy the existing file to a TFTP host as a backup just in case the new image crashes and burns.
And you can use any TFTP host to accomplish this. By default, the flash memory in a router is used to store the Cisco IOS. In the following sections, I’ll describe how to check the amount of flash memory, how to copy the Cisco IOS from flash memory to a TFTP host, and how to copy the IOS from a TFTP host to flash memory.
You’ll learn how to use the Cisco IFS to manage your IOS files after first learning how to manage them with a TFTP host.
But before ...