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Remove or Fix 'bad cksum' Firmware Image

New Contributor II

I am experiencing an issue where i am unable to connect an AP to a ZD. It appears that the issue is because the FW downloaded has an error 'bad cksum' (please see below). Is there anyway i can overwrite this or delete it?

AP model: 7363

hdr_cksum:    0x63F0 != 0x0187 - bad cksum
version:       ( )


RUCKUS Team Member
Do you have access to AP CLI or GUI? If not, you need RMA.
If you have access to GUI, you can install AP image from local PC.
If you have only CLI, you can install AP image from tftp server by the following steps.

fw set proto tftp
fw set host
fw set control
fw update

You can download AP standalone image from Ruckus Support.

Masaaki Yamada

New Contributor II
Hi Masaaki,

Thanks for the reply.

I have access to CLI & GUI. 

I attempted looking for the firmware for a 7363 on Ruckus Support and could not find it. Any chance you could point me in the right direction so i can find the file?

Kind regards,


New Contributor III
There isn't a way to delete the file from the AP command-line. But when you re-try the connection, the AP will try to download the firmware again.  If it is continually corrupt after download, there could be another issue, whether that is on the AP itself, in the firmware image, or the network.

You could try a manual transfer of the file using TFTPD32 or Filezilla FTP server and see if you ahve more success. Commands on the AP are:

You can download a copy of the 7363 firmware by enabling FTP on the ZD, presuming your networks' security policies allow this

 a. enable FTP on ZD:

 b. Open a web browser to ftp://x.x.x.x (IP of your ZD)
 c. Login, browse to the directory 'zf7363' and download a copy of the firmware.
 d. Put the newly downloaded firmware in your TFTP root directory. If you can, run checksum on it.

Now that you have the file on your own TFTP server and know the checksum, SSH to the AP and try to download it from your TFTP server:

  fw set proto tftp
  fw set host x.x.x.x (IP address of your TFTP server)
  fw set control
  fw update

After this, the AP will boot-up and hopefully take load the AP firmware.

If problems persist, I'd recommend logging a case with Support and providing the APs support-log. You can get this by:

1. Recreating the problem
2. SSH into the AP
3. Type 'support'
4. Type 'support show' and save the output into a txt file.


RUCKUS Team Member
Hi Oliver,

ZD-AP image is bundled in ZD image, so we do not provide ZD-AP image directly.
You can install standalone image, e.g. and then try to join to ZD again.

Masaaki Yamada