So, read about it plenty of times but never actually done it – until today. Have to say, it’s a hair raising few moments waiting for the device to start booting from the new image but very satisfying when it does. These are the steps I took – no warranty implied, do it at your own risk.
1. Install TFTPD32 on computer, verify upload of file from a Cisco device with known good connectivity
2. Upload the .bin file from the device where the OS is to be upgraded to the TFTP server. This is to ensure that there is a fall-back plan if the new image doesn’t work. It was not possible in this case to store both images at the same time on the switch.
3. Upload the image from the switch with the desired OS version to the TFTP server
4. Delete the old image from the switch to be upgraded.
* DO NOT RELOAD *
5. Download the desired image from TFTP to the flash of the to-be-upgraded device
6. Configure the switch to boot from the new image:
Switch(config)#boot system switch all flash:/c3750-imgname.bin
Switch(config)#exit
Switch#copy run start
7. Verify the boot variable:
Switch#Show boot
8. Clench, and reload the switch 😉
Jims' Network Diary - musings of a network admin 