When replacing a faulty router that is not completely dead, it may be possible to copy the startup configuration to the removable flash memory and swap the flash to get the new router up and configured in as short a time as possible. Without this procedure, manually copying the old configuration to the new router will be necessary. This simple command also provides a local backup copy of the router’s config which can save hours of work when replacing a dead router.
To copy the startup-config to flash as a file called backupconfig, use the following command:
copy startup-config flash:backupconfig
It will verify the destination filename. (Just press Enter to continue.) This must be done on the old router. (I try to do it whenever I make a configuration change.)
When moving the configuration to another router, physically move the flash memory, power on the router, and answer “no” to the system configuration prompt. Enter enable mode. (No password should be required if this is an unconfigured router.) Then use the following command to load the configuration from flash:
copy flash:backupconfig running-config
This pulls the configuration out of flash and makes it the current running configuration. While it is possible to copy the config directly into the startup-config and reload the router, I like to place it into running-config directly to make sure that everything comes up as it should.
When you copy into running-config, all of the interfaces will be administratively down. You will need to configure each interface with a “no shut” (short for no shutdown).
Doing this manually will give you the warm, fuzzy feeling of watching the interfaces come up. However, if there are more than a handful of interfaces, copying to the startup-config will save time.