Re: Failing to netboot

[Julian Coleman <jdc%coris.org.uk@localhost>]

Hi,

> Apr 27 21:54:12 pie atftpd[104415]: Serving C0A817D3.SUN4C to
> ::ffff:192.168.23.211:47441
> 
> No matter what I do though I get “Transfer failed, The file downloaded
> does not appear to be executable.”

> I would try to check the memory content from OBP and compare to the
> file on the server.
> 
> Or use a tftp client on another machine to download the file and compare
> it.

I think that this last is definitely the best option.  I can't remember if
OBP will give the above error if no file is received or the connection is
otherwise interrupted.  Looking through our archives, I didn't notice any
similar posts.   I also checked some online Ubiquiti questions, and I was
wondering if the file is not transferred even though the tftp server logs
the request.  One article [1] notes:

  "The problem was with Unifi's intrusion detection. It was seeing a TFTP as a possible threat and automatically blocking it, after putting it on the allow list, it was able to pull down the image. "

Less likely to me is that the file is being corrupted in transfer.  TFTP [2]
supports both binary (octet) and netascii modes, where netascii mode could
corrupt a binary file.  However, it seems quite unlikely to me that the
tftp server is not sending the file in binary mode.

Regards,

Julian

[1] https://www.reddit.com/r/Ubiquiti/comments/1ef6p13/trying_to_pxe_boot_via_the_dhcp_options_on_dream/
[2] https://www.rfc-editor.org/rfc/rfc1350