Cisco Switch: Upgrading Firmwares & Recovering from Failed ones !

If it ain’t broke, don’t fix it ! So true Z@ib

Quick notes for myself:

After recent detailed network/systems audit, we had to upgrade several cisco switches firmwares. During the upgrade/update process, I encounter some issues & this post is for my personal reference purposes. Please beware that I donot hold any prior experience in handling cisco related gears/device but when you are enslaved by private job & working as one man army, you have to perform many task in which you are not formally trained for.

Maybe this post will help some other novice like me

Regard’s
Syed Jahanzaib

WS-C3650-48PD

Fortunately this model have nice GUI which supports easy upgrade of firmwares , therefore I used it to upgrade to latest stable build Fuji-16.9.4

SG300-28PP/SG500-52PP

This model also have nice GUI which supports easy upgrade of firmwares , therefore I used it to upgrade to latest stable build

https://www.cisco.com/c/en/us/support/switches/sg500-52-52-port-gigabit-stackable-managed-switch/model.html#~tab-downloads

3750X-48T-S

.

WS-C3750E-24TD

OLD version:

WS-C3750E-24TD     12.2(40)SE

Steps for Upgrade:

First setup new or use existing TFTP server, download the new firmware from

https://software.cisco.com/download/home/280831016/type/280805680/release/15.0.2-SE11?i=!pp

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

copy tftp: flash:

It will ask the tftp server IP, and source/destination file name, fill them up as per your local scenario

>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>
exit
wr
reload

after this switch will reboot , and new firmware will be overwritten.

New version:

Release 15.0.2-SE11 MD

WS-C3850-24T

Notes:

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

• Gibralter 16.12.1 ED : 3850 / Switch was doing reboot 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 Light issue

With this upgrade , switch booted but 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 which worked fine & stable.

Steps for Upgrade:

First setup new or use existing TFTP server, download the new firmware from

https://www.cisco.com/c/en/us/support/switches/catalyst-3850-24t-s-switch/model.html#~tab-downloads

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

after this switch will ask to reload , do so to apply changes

New version:

16.3.9

Recovering from IOS FAILED upgrade on 3850 Switch

after the Gibralter firmware upgrade , 3850 switch wen into reboot loop.

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

More infor on this issue mentioned here @ https://community.cisco.com/t5/switching/catalyst-c3850-gibraltar-16-12-1-ed/td-p/3907723

After entering recovery mode , I made the situation worsen by deleting some flash files. This is how I recovered from this situation.

from the switch Management port, connect a cable directly to your laptop/desktop & assign any private IP on the system like 192.168.99.1/24. Install any free TFTP server like SOLARWINDS TFTP Server. copy the stable firmware like DENALI 16.0.3.09 in the tftp root folder.

cat3k_caa-universalk9.16.03.09.SPA.bin

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

• flash_init
• mgmt_init
• set IP_ADDR 192.168.99.2/255.255.255.0
• set default_router 192.168.99.1
• emergency-install tftp://192.168.99.1/cat3k_caa-universalk9.16.03.09.SPA.bin

There was another easy method by connecting USB into usb port of switch, but since switch may not recognize most modern usb’s , therefore I had to take a long route of TFTP.

To read in more details , refere following post

http://blog.unolution.com/networking/how-to-recover-a-cisco-switch-3560x-3750x-from-boot-loader/

Regard’s
Syed Jahanzaib