Boot using USB Drive
The bootable USB drive is used to re-image the router for the purpose of system upgrade or boot the router in case of boot failure. The bootable USB drive can be created using a compressed boot file.
Create a Bootable USB Drive Using Compressed Boot File
A bootable USB drive is created by copying a compressed boot file into a USB drive. The USB drive becomes bootable after the contents of the compressed file are extracted.
In case of failure to read or boot from USB drive, ensure that the drive is inserted correctly. If the drive is inserted correctly and still fails to read from USB drive, check the contents of the USB on another system.
This task can be completed using Windows, Linux, or MAC operating systems available on your local machine. The exact operation to be performed for each generic step outlined here depends on the operating system in use.
Before you begin
Have access to a USB drive with a storage capacity that is between 8GB (min) and 32 GB (max). USB 2.0 and USB 3.0 are supported.
Copy the compressed boot file from the software download page at cisco.com to your local machine. The file name for the compressed boot file is in the format asr9k-usb-boot-<release_number>.zip.
Connect the USB drive to your local machine and format it with FAT32 or MS-DOS file system using the Windows Operating System or Apple MAC Disk Utility.
Copy the compressed boot file to the USB drive.
Verify that the copy operation is successful. To verify, compare the file size at source and destination. Additionally, verify the MD5 checksum value.
Extract the content of the compressed boot file by unzipping it inside the USB drive. This converts the USB drive to a bootable drive.
Eject the USB drive from your local machine.
What to do next
Use the bootable USB drive to boot the router or upgrade its image.