Cisco IOS Upgrade to 16.x from 3.x for IOS XE

- Pre-requisites

  : For IOS XE 16.x, the router must be running a minimum version of 16.2(1R) of ROMMON

  : This upgrade procedure only applies to the ISR 4000 series of routers

  : Will need to download the IOS image and upload the image to the ISR 4000's bootflash

  : Will need to download the latest ROMMON image and upload to the ISRO 4000's bootflash

 

- Upgrade

  1. check the version of ROMMON currently running on the router. => show rom-monitor r0

  2. verify the platform hardware and firmware versions and be sure to download the corresponding image file for the hardware => show platform (i.e. output is ISR4331)

  3. copy the rommon image to the flash of the ISR 4000 router and verify that the image is in the router's flash => copy ftp: flash:  (followed by questions about ftp svr ip,  src file, dst file.

  4. upgrade the ROMMON using the uploaded image from flash. Once the image is upgraded, save the configuration and reboot the router. => upgrade rom-monitor filename bootflash: <pkg name> all

  5. Once the router comes back online, verify the ROMMON version by issuing the same commnad as before => show rom-monitor r0

  6. Upgrade the router by changing the boot variable as normal, save the configuration and reload the router => router(config)# Boot system bootflash:/ isr4300-universalk9.16.09.03.SPA.bin 

  7. The last step is just to verify that the router has successfully upgraded to version IOS XE 16.9.3. => show version

 

 

<Reference>

- https://www.lookingpoint.com/blog/upgrade-cisco-isr-4000-series-routers