C1941 Router IOS Upgrade from 150-1.M3 to 157-3.M8(MD)

[Alan.A]

I have a C1941/K9 router running IOS verison of "150-1.M3" Can I upgrade it directly to 157-3.M8(MD)?
Do I need to upgrade first the rommon from 15.0(1r)M9 to 150-1r.M16?

EXISTING IMAGE:---c1900-universalk9-mz.SPA.150-1.M3.bin
EXISTING ROM: --- ROM: System Bootstrap, Version 15.0(1r)M9

UPGRADED TO: --- c1900-universalk9-mz.SPA.157-3.M8.bin
UPGRADED TO: --- C1900_2900_RM2.srec.SPA.150-1r.M16

[Leo Laohoo · Accepted solution]

It is highly recommended if the ROMMON can be upgraded.  

But yes, upgrade to 15.7(3)M train is achievable with/without upgrading the ROMMON.

[Alan.A]

Appreciate your support Leo. Thank you so much. one more question.

The process in upgrading rommon of ISR G1 router like 1941 is boot first the Rommon and second is the current Image and reload?

after the rommon upgrade I can follow the usually process for the image upgrade.

Update the boot system to rommon and second the existing image

boot-start-marker
boot system flash0:/C1900_2900_RM2.srec.SPA.150-1r.M16
boot system flash0:/<Existing IMAGE>
boot-end-marker

make sure Configuration register is 0x2102

reload
!

[Leo Laohoo · Accepted solution]

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@Alan.A wrote:

The process in upgrading rommon of ISR G1 router like 1941 is boot first the Rommon and second is the current Image and reload?

---

Depends on who you are talking to. 

Cisco documentation recommends rebooting after the ROMMON upgrade (1 reboot) and another reboot for the IOS upgrade (1 reboot). 

What I usually recommend is upgrade the ROMMON, do not reboot, copy the new IOS and reboot.  This means only 1 reboot and the ROMMON and IOS gets upgraded in a single stroke.

[Alan.A]

Upgrade successful to 15.7(3)M without upgrading the rommon.. thank you