Boot Devices

There are three devices from which the router boots: the flash drive, the hard drive, or a removable medium. Typically, the router boots from the flash disk. The disk from which the router boots is called the primary boot device, and the other disk is the alternate boot device. The primary boot device is generally the flash disk, and the alternate boot device is generally the hard disk.

If the router boots from an alternate boot device, a yellow alarm lights the LED on the router's craft interface. For information about chassis conditions that trigger alarms, see Chassis Conditions That Trigger Alarms.