Corrupt boot image, stuck in rommon.

[woter1832]

Hi,

I uploaded an IOS boot image to my C897VAW and ran the following:

C897VAW(config)# no boot system flash c800-universalk9-mz.SPA.156-3.M4.bin

C897VAW(config)# boot system flash c800-universalk9-mz.SPA.152-4.M6a.bin

C897VAW(config)# exit

C897VAW# wri me

C897VAW# reload

The 

c800-universalk9-mz.SPA.156-3.M4.bin

file is still on the router.

I thought the 

c800-universalk9-mz.SPA.152-4.M6a.bin

file was fine as I thought it was the copy I was using before upgrading to 156-3.M4, but after downloading it again, it's 10MB smaller and therefore corrupt.

What's the best way out of this pickle? Is there any way to modify or replace the startup-config via rommon or do I need to follow the lost password procedure? 

(I was trying to downgrade so I could delete 156-3.M4 to get enough space to upload 157-3.M1).

Many thanks

W.

[Leo Laohoo]

---

@woter1832 wrote: 

C897VAW(config)# boot system flash c800-universalk9-mz.SPA.152-4.M6a.bin 

---

That is the wrong syntax.  It should be

boot system flash flash:<FILENAME>.bin.

[Leo Laohoo]

---

@woter1832 wrote:

I thought the 

c800-universalk9-mz.SPA.152-4.M6a.bin

file was fine as I thought it was the copy I was using before upgrading to 156-3.M4, but after downloading it again, it's 10MB smaller and therefore corrupt. 

---

1.  Download the file again.  

2.  Compare the MD5 hash of the file downloaded against the MD5 hash found in the Cisco website.  Make sure they are a match. 

3.  After verification, copy the file to the router.  

4.  Compare the MD5 has of the file found in the router.  Make sure they match again.  

5.  Change the boot variable string of the router. 

6.  Make sure the config-registry value is 0x2102. 

7.  Save the config and reboot.

[woter1832]

Thanks @Leo Laohoo,

I must be misunderstanding you. The router only boots into rommon. If I change the register, will it not try to load the config, find the corruption and go straight back into rommon?

Do I need to break into RP / SP or something? (Clutching at straws).

---

@Leo Laohoo wrote:

---

---

7.  Save the config and reboot.

---

How do I save the config in rommon? 

Thanks

W.

[Leo Laohoo]

Ok then. Console into the router and reboot. We want to see what is causing the router to boot into ROMmon.

[woter1832]

Hi @Leo Laohoo,

As requested, I've connected up to the console and rebooted. Here is the output:

System Bootstrap, Version 15.2(3r)XC, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 2012 by cisco Systems, Inc.


Total memory size = 1024 MB

C897VAW-E-K9 platform with 1048576 Kbytes of main memory

Main memory is configured to 32 bit mode 


Readonly ROMMON initialized

program load complete, entry point: 0x4000000, size: 0x18c40

program load complete, entry point: 0x4000000, size: 0x18c40

loadprog: error - on load of image from file system with monlib

Image size (40204800) does not match the expected size (51981580)

open: failed to find and/or load the bootloader: "flash:c800-universalk9-mz.SPA.152-4.M6a.bin"

loadprog: error - on file open

boot: cannot load "tftp:/undefined 255.255.255.255"


System Bootstrap, Version 15.2(3r)XC, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 2012 by cisco Systems, Inc.


Total memory size = 1024 MB

C897VAW-E-K9 platform with 1048576 Kbytes of main memory

Main memory is configured to 32 bit mode 


Readonly ROMMON initialized

program load complete, entry point: 0x4000000, size: 0x18c40

loadprog: error - on load of image from file system with monlib

Image size (40204800) does not match the expected size (51981580)

boot: cannot load "flash:c800-universalk9-mz.SPA.152-4.M6a.bin"


System Bootstrap, Version 15.2(3r)XC, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 2012 by cisco Systems, Inc.


Total memory size = 1024 MB

C897VAW-E-K9 platform with 1048576 Kbytes of main memory

Main memory is configured to 32 bit mode 


Readonly ROMMON initialized

program load complete, entry point: 0x4000000, size: 0x18c40

program load complete, entry point: 0x4000000, size: 0x18c40

loadprog: error - on load of image from file system with monlib

Image size (40204800) does not match the expected size (51981580)

boot: cannot load "flash:"


System Bootstrap, Version 15.2(3r)XC, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 2012 by cisco Systems, Inc.


Total memory size = 1024 MB

C897VAW-E-K9 platform with 1048576 Kbytes of main memory

Main memory is configured to 32 bit mode 


Readonly ROMMON initialized

program load complete, entry point: 0x4000000, size: 0x18c40

program load complete, entry point: 0x4000000, size: 0x18c40

loadprog: error - on load of image from file system with monlib

Image size (40204800) does not match the expected size (51981580)

boot: cannot load "flash:"


System Bootstrap, Version 15.2(3r)XC, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 2012 by cisco Systems, Inc.


Total memory size = 1024 MB

C897VAW-E-K9 platform with 1048576 Kbytes of main memory

Main memory is configured to 32 bit mode 


Readonly ROMMON initialized

rommon 1 > 

Many thanks,

W.

[chrihussey]

You could try loading and booting off the new image using the rommon tftpdnld utility. You essentially give the router a temporary IP address and can download new code then boot the router. I believe this method would also remove the corrupt image.

Here is the Cisco link:

https://www.cisco.com/c/en/us/td/docs/routers/access/800/software/configuration/guide/SCG800Guide/SCG800_Guide_BookMap_appendix_010101.html#con_1013611

and another that may be a bit easier to understand:

https://ippacket.com.au/cisco-tftpdnld-rommon-command-recovery/

Keep in mind the commands are case sensitive so where caps are used, they should be entered in just that way.

Hope this helps

[woter1832 · Accepted solution]

Thank you to all that posted replies. I'm up and running again. I followed this accepted solution. The key for me was to run the command:

rommon 2 > boot flash:c800-universalk9-mz.SPA.156-3.M4.bin

This allowed the router to boot properly and for me to change the configuration to:

boot system flash flash:c800-universalk9-mz.SPA.156-3.M4.bin