Failed in Upgrading Firmware’s & Recovering?

Quick notes for myself: Disclaimer! This can be important!

My humble request is that kindly do not take into account ME as Associate in Nursing knowledgeable on these items, I’m NOT certified in something Mikrotik/Cisco/Linux or Windows. But I even have worked with some core networks and that I browse, analysis & strive stuff all of the time. After you are enthralled by personal job & operating united man army, you have got to perform several tasks within which you’re not formally trained for. therefore I’m not speaking/posting regarding stuff I’m erstwhile trained in, I just about go along with expertise and what I even have learned on my very own. And, if I don’t understand one thing then I browse & learn all regarding it.

So, please don’t hold me/my-postings to be invariably 100% correct. I build mistakes similar to everyone else. but – I do my best, learn from my mistakes and check out to assist others

Maybe this post can facilitate another novice like ME


Fortunately this model have nice user interface that supports simple upgrade of firmware’s , so I used it to upgrade to latest stable build Fuji-16.9.4


This model even have nice user interface that supports simple upgrade of firmwares , so I used it to upgrade to latest stable build



OLD version:

WS-C3750E-24TD     12.2(40)SE

Steps for Upgrade:

First setup new or use existing TFTP server, transfer the new code from!pp

& copy the code file (.BIN format) in TFTP root folder. currently from switch console , copy the file from TFTp into switch FLASH

copy tftp: flash:
It will raise the tftp server scientific discipline, and source/destination file name, fill them up as per your native state of affairs

>Address or
name of remote host? <IP_ADDRESS_OF_TFTP_SERVER>
>source filename? <IMAGE_NAME.bin>
>Destination filename? <IMAGE_NAME.bin>
conf t
boot system flash:<IMAGE_NAME.bin>

After this switch can bring up, and new code are overwritten.

New version:

Release 15.0.2-SE11 MD


With this model, I encountered few problems in upgrading 3850 switch.

Gibralter sixteen.12.1 impotence : 3850 / Switch was doing bring up in loop with following error
Kernel panic – not syncing: VFS: Unable to mount root fs on unknown-block(1,0)

Fuji 16.9.4 MD : 3850 / Switch Port Orange lightweight issue
With this upgrade , switch shod however all ports lights runed to amber.

Denali 16.3.9 MD : 3850 / Well tested , worked OK
Therefore I reverted back to to Denali-16.3.9 that worked fine & stable.

Steps for Upgrade:

First setup new or use existing TFTP server, transfer the new code from

>Address or name of remote host? <IP_ADDRESS_OF_TFTP_SERVER>
>source filename?
filename? <IMAGE_NAME.bin>
conf t
software install file
flash:cat3k_caa-universalk9.16.03.09.SPA.bin new force verbose

After this switch can raise to reload , do therefore to use changes

New version:

Recovering from IOS unsuccessful upgrade on 3850 Switch
after the Gibralter code upgrade , 3850 switch sebaceous cyst into bring up loop.

Kernel panic – not syncing: VFS: Unable to mount root fs on unknown-block(1,0)

More infor on this issue mentioned here @

After getting into recovery mode , I created the case worsen by deleting some flash files. this can be however I recovered from this case.

from the switch Management port, connect a cable on to your laptop/desktop & assign any personal scientific discipline on the system like Install any free TFTP server like SOLARWINDS TFTP Server. copy the stable code like McKinley sixteen.0.3.09 within the tftp root folder.


Now mistreatment any terminal tool like putty, connected to change via CONSOLE port, press MODE button whereas booting & entered RECOVERY mode. & issued following CMD’s

set default router
emergency-install tftp://

There was another simple methodology by connecting USB into usb port of switch, however since switch might not acknowledge newest usb’s , so I had to require a protracted route of TFTP.

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