Updating CISCO SG200-26 Firmware

I’ve got a Cisco SG200-26 switch, and it has a Firmware Version (Active Image): and Boot Version:

I tried to update the (latest) firmware sx200_fw-14088.ros via http, and …
it failed, stating there was an ‘error “illegal software format”’ – WTF ?
I’ve tried http/https, and TFTP same result. A google search later gave an answer.

I have to upgrade to intermediate firmware(S) before being able to install the latest firmware release.
Almost Like a Microsoft update style here.

The 1st intermediate release seems to be the which include both a .ros firmware file and a .rfb boot file.

But to be able to install it we need to install first.
This time file upload completes fine via http. A reboot later and new firmware has been applied.
Note : I had to save the configuration.

Now let’s try to upload the files (boot and firmware) via tftp.
My tftp is enabled by default on my OsX Server as I have deploy Studio.
if you need to enable it on a Os X Client :
go download tftpserver here and search for the Lion Version or the latest for OsX below 10.6.x

I then copied files to /private/tftpboot
Note : You have to put the file at the root of the tftp server.

sudo cp sx200* /private/tftpboot/

Then on the cisco, go back to :
File Management -> Upgrade/Backup Firmware/Language

Choose TFTP enter your computer IP: 192.168.xxx.yyy
then the filename: sx200_fw_1.3.7.18.ros
– The file upgrade will take effect only after the switch has been rebooted. –
as before once done, reboot.
This time no need to save the config after reboot.


Note : router seems to be loading faster.

Update the boot file.
Here NO choice, TFTP is the only way to go. – that’s why I tried previously tftp for the firmware update
Again reboot to apply. It took a long time to reboot. be patient (I was a bit stress I admit)


Note : boot file sx200_boot-13506.rfb has the same label for the and the firmware.

Next, do the same to upload and update the firmware. reboot.

Switch is now upgraded with the latest firmware (to date)


Note : interface has slightly changed in the VLAN tab (and maybe elsewhere)

below the urls to get the firmwares :
cisco sg200-26 :
cisco rv220w :

url that helped:


I did update firmware as I had trouble creating VLANs between RV220W and SG200-26 CISCO devices.
But this had nothing to do I was just not getting it right.


Product and graphic designer turned to be a Mac SysAdmin.

Posted in Admin Tagged with: , , , , , ,
5 comments on “Updating CISCO SG200-26 Firmware
  1. Avatar Mike Ethier says:

    This is great information. I was able to upgrade my SG200 using your document.

    Thank you.

  2. Avatar Mike V says:

    Great info mate! The same procedure worked well for me with an SG300.

    The secret to getting around the “illegal software format” error message seems to be using TFTP rather than HTTP, and upgrading the firmware and boot files in small steps rather than making a big jump straight to the latest version.


  3. Avatar Alexey says:

    I am try from you instuction on
    SG200-50P 50-Port Gigabit PoE Smart Switch
    work fine.

    Thank you.

  4. Avatar Thom K says:

    Thank you for putting together this guide. It was very helpful to me.

  5. Avatar JP says:

    Thank you so much. It was very very helpful.

Leave a Reply

Your email address will not be published. Required fields are marked *


You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>