Help fixing a 3650 downgrade 16.03.08 to 03.06.06E

[Mottok]

Hi, ok my first IOS 'install' and I messed up and really need help. I have a new 3650 switch with 16.03.08 and attempted (poorly) to downgrade to 03.06.06E to match all our other switches. I followed the guidelines below (realise I should have used the "request platform software package install" in the release notes) but used these instead:

- Copied the 03.06.06E bin file to flash

Then:

switch#config t
switch#(config) boot system flash:cat3k_caa-universalk9.SPA.03.06.06.E.152-2.E6.bin
switch#(config)exit
switch#reload
switch#(confirm) y

Switch rebooted and now reboots constantly with "no such file or directory". If I can get the switch back to original setup I can then go ahead with the "request platform software package install" step but no idea how to do that or what has caused this. 
Please help, many thanks.

[Leo Laohoo]

CSCul95378

[Mottok]

Hi, thanks for getting back to me. I don't see that error anywhere (the "BIST failed" part), how can you tell it's the same error? Also, can I get back to the original 16.03.08 (as I can't move to 03.06.07E)? Thanks

[balaji.bandi]

Power off the device, connect the console cable and power on the device if the boot properly without any issue is good,. or it gets into ROMMON, we can suggest steps based on the output.

you may be required as per the BUG, but that only confirms once we see the boot process.

"does not resolve the issue, then the switch should be replaced via RMA. No EFA is required."

[Mottok]

OK remember I'm just a noob so ROMMON doesn't mean much to me. The screen shot and all info thus far is from me rebooting with console cable attached. So how do I know if I am in ROMMON? I presume I'm not if as I said the switch reboots itself after the screenshot I posted?

There must be an easy way to get back to the original boot config/Location? Many thanks

[Leo Laohoo]

If the switch came with 16.X.X, try downgrading to 3.7.X.

[Mottok]

Hi, really appreciate everyone's help but how do I stop the switch from rebooting and get it to a state that can perform the downgrade to 3.7.x?

[balaji.bandi]

Ok let's do the simple steps :

Pre-requisites:

Download 3.7.x version from cisco software download site, copy  the image .bin file into USB (make sure USB formatted FAT32). 

Connect the USB to Switch.

1. Power off the device or remove the power cord from the device.

2. connect the console cable (you already connected as per post output)

3. connect the power cord to the device while booting process taking place - within 15 seconds Hold the MODE button. when SYSTEM LED flashing, after few seconds you see below prompt.

switch:

check with below command you can see files in USB

dir usbflash0:

switch: flash_init
switch: load_helper
switch: boot usbflash0:/NEWBIN.bin  ( replace NEWBIN with Exact name of the nin file you download from cisco site)

let us know how the above steps go, post all the logs back to post if any issue to suggest better.

[Mottok]

Many thanks for that. I actually went through at least part of these steps before and I'm sure the flash_init came back as an unrecognised command. I also booted from the USB and it failed the same way, although this was with the 3.6.6E iso so maybe that's always going to be the case.

I'll try these steps when back in the office with a different iso version and post back the results. At least I'm learning!

Thanks all.

[Leo Laohoo]

Emergency Recovery

[balaji.bandi]

Sorry that command did not work  - try below steps :

Standard Recovery Methods

This section describes the two standard methods that are used in order to recover from a Catalyst 3850 Series Switch boot failure.

USB Recovery

The 3850 Series Switches have a USB port on the front that is used for console access. This USB port is also used with flash drives for image backup and recovery.

If you become stuck at the switch: prompt with a corrupt image or .conf file, you can easily boot to a file that is stored on the USB drive or copy an image from the USB to internal flash. Complete these steps in order to recover from the boot failure:

1. Verify that the flash drive is recognized and the .bin file exists:
   
   

   switch: 

   dir usbflash0:

   
   Directory of usbflash0:/
   74  -rw-  223734376  cat3k_caa-universalk9.SPA.03.03.00.SE.150-1.EZ.bin

2. Boot to the USB image:
   
   

   switch: 

   boot usbflash0:NEWIMAGE.bin   <----replace NEWIMAGe with correct image name of the IOS

[Mottok]

Many thanks. Looks like that is what I did using a USB drive but with the 3.6.6E ios. If I place the 16.03.08 ios on the USB and boot from that should it basically be back to how it was originally do you think?

Thanks.

[balaji.bandi]

Once it boots from USB, you need to check what IOS image available in the flash and remove unwanted images from flash.

Copy working IOS image from USB to Flash, if this is bundle mode :

you need to change boot variable - 

boot flash:image.bin   <<- replace the image with correct IOS image name

write 

reload - it should boot from flash.

Note: since you have tried all the steps as you have mentioned, we suggest to capture all the logs while doing the process, post those log if it fails.

[Mottok]

OK will do just that, thanks very much.