[syslinux] syslinux.efi and vendor-class-identifier

[James Pearson]

Gene Cumm wrote:
> 
> On Fri, Oct 11, 2019 at 10:27 AM James Pearson via Syslinux
> <syslinux at syslinux.org> wrote:
>>
>> James Pearson via Syslinux wrote:
>>>
>>> However, I have just tested the exact same boot procedure using a Dell
>>> laptop (Latitude 7480) - and it all worked without a problem - that is,
>>> syslinux.efi and ldlinux.e64 were downloaded without a problem - and
>>> from a tcpdump, there was *no* DHCP transaction between downloading
>>> syslinux.efi and ldlinux.e64
>>>
>>> So I'm puzzled as to why it doesn't work on the Dell 3930 - may be a
>>> firmware bug/feature (it is running the latest firmware) ?
>>
>> Also tested with an HP laptop (Zbook 15u G5) and this shows the _exact_
>> same issue as with the Dell 3930 ... so the issue is looking more and
>> more like a problem somewhere with syslinux.efi ?
> 
> It's a client-specific interaction that I haven't seen.  My guess is
> the attempts to just use the default address works better on some
> clients but triggers this second DHCP cycle on other clients.
> 
> I'm assuming whatever versions you're using are the precompiled
> binaries from the source/binary tarballs from kernel.org?
> 
> In the packet captures, I'm guessing the UEFI firmware did DHCP, fetch
> syslinux.efi then very quickly thereafter started the broken DHCP
> cycle?

I'm using the binaries from the tarballs at 
https://www.zytor.com/pub/syslinux/Testing/6.04/

I can provide a raw packet capture if it helps?

James Pearson