[Dnsmasq-discuss] Do "proxy-DHCP" without PXE

[Simon Kelley]

The latest release, 2.91, includes a new option --dhcp-option-pxe, which 
may be of use here.

Cheers,

Simon.


On 28/04/2025 13:32, Steven Maddox wrote:
> Hello,
> 
> Sorry if what I'm about to ask is impossible, but I just really needed 
> to know one way or another.
> 
> I find dnsmasq such a handy utility for all kinds of situations (so huge 
> thanks for creating it!)... one such situation was back when I was 
> working with ThinStation and I'd do something like this to quickly test 
> how a new build would boot on some PXE enabled machines...
> 
> dnsmasq -d -i enp2s0 -F192.168.1.0,proxy --enable-tftp --tftp- 
> root="$(pwd)/build/boot-images/pxe" -p0 --log-dhcp --pxe- 
> service=x86PC,'Network Boot',boot/lpxelinux/lpxelinux
> 
> Ultimately it's the "proxy-DHCP" that I'm focussing on here.
> 
> Would it be possible to use this technique to add extra arbitrary DHCP 
> options to a reply instead?  without touching the config of the 
> authoritative "other" DHCP server? e.g...
> 
> dnsmasq -d -i enp2s0 -F192.168.1.0,proxy --enable-tftp --tftp- 
> root="$(pwd)" -p0 --log-dhcp -O 160,tftp://192.168.1.2
> 
> This would be really handy in a scenario where you need to tell a bunch 
> of devices (e.g. Polycom phones) a new provisioning URL (in that example 
> option 160) on a temporary basis whilst you reboot/factory-reset them. 
> Especially when you're stuck using whatever existing DHCP server is on 
> the network with no ability (or great difficulty) to reconfigure it.
> 
> But I have a feeling I'm going to be told that "proxy-DHCP" is, and can 
> only be, a PXE specific thing?  if so, what is that?
> 
> Thanks
>