Upgrading ISR4300 from IOS XE to IOS - does ROMMON need to be upgraded?

[stuartbedale]

I am about to upgrade a voice gateway ISR4321/K9 from

isr4300-universalk9.03.16.04b.S.155-3.S4b-ext.SPA.bin

to

isr4300-universalk9.16.12.03.SPA.bin

Cisco documentation suggests the ROMMON version will need to be upgraded

www cisco.com/c/en/us/td/docs/routers/access/4400/cpld/isr4400_hwfp.html

Upgrading Field-Programmable Hardware Devices for Cisco 4000 Series ISRs

"Note When you upgrade from Cisco IOS XE 3.x to 16.x image, you should first upgrade the rommon release to the 16.7(5r) rommon release. After upgrading to the 16.7(5r) rommon release, based on the IOS XE 16.x image, the rommon release can be auto-upgraded to a later rommon release."

The ROMMON version is 16.7(1r)

ROUTER#show rom-monitor0r 0r0

System Bootstrap, Version 16.7(1r), RELEASE SOFTWARE
Copyright (c) 1994-2017 by cisco Systems, Inc.

ROUTER#

but I have seen other comments that suggest I don't need 16.7(5r)

Cisco ISR 4000 Router Upgrade Guide from 3.x to Denali 16.2

www labminutes.com/blog/2016/04/cisco-isr-4000-upgrade-guide-3x-denali-162

"The router must have minimum ROMMON version of 16.2(1r)"

and

Upgrade Cisco ISR 4000 series of Routers to 16.X from 3.X for IOS XE

www cisco.com/c/en/us/td/docs/routers/access/4400/cpld/isr4400_hwfp.html

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

Which version is correct, have Cisco made a typo?  Eeek!

Or can I just amend the boot statements, reload and rely on the new IOS to upgrade the ROMMON?

ROUTER(config)#boot system bootflash:isr4300-universalk9.16.12.03.SPA.bin
ROUTER(config)#boot system bootflash:isr4300-universalk9.03.16.04b.S.155-3.S4b-ext.SPA.bin

Thanks

[Roger Kallberg]

You should upgrade rom before and btw both of these IOS is XE based.

[stuartbedale]

In the end I just rebooted with the bootflash statements and all worked fine. I think if the ROMMON has been 15. there may have been an issue, but as I has 16.7(1r), the IOS upgrade handled the ROMMON upgrade too.

The only oddity is that my box has moved from CSL licensing to Smart Licensing, and I just have to work out what to do to ensure no loss of function along with license compliance.