[Dnsmasq-discuss] Disable dhcp-option for a single host

[Nothing New]

On Sun, Jun 05, 2022 at 07:41:03AM -0400, Brian Rossa wrote:
> Hello,
> 
> I'm doing some firmware-related work and am using a --dhcp-hostsdir setup
> to test several devices on my LAN. This is working fine, but I appear to
> have hit the limits of my dnsmasq-fu when attempting to *toggle* the DHCP
> options for a particular end host.
> 
> Namely, (1) the global config sets enable-tftp and (2) the hostsdir config
> for the target device starts as "{mac},{ip},set:green". During my test I
> (3) update it asynchronously to "{mac},{ip},set:red" and (4) hit dnsmasq
> with SIGHUP. According to my understanding, this will cause dnsmasq to
> clear its host cache and reload the hostsdir configs.
> 
> The only remaining question, then, is how to specify individual dhcp-option
> disablement for the target. Specifically, for "red" tags, I tried the
> following configuration to override the global tftp-enable setting:
> 
> dhcp-option=tag:red,option:tftp-server,""
> dhcp-option=tag:red,option:tftp-server-address,""
> dhcp-option=tag:red,option:boot-file-size,""
> dhcp-option=tag:red,option:bootfile-name,""
> 
> Unfortunately, this approach seems to be flawed as the service complains
> that empty string is an invalid option and never comes up.
> 
> Is there a common "disable" flag for scenarios like this? If so, I could
> not find it in the docs. If not, what approach is recommended for these
> kinds of per-host override situations?

https://duckduckgo.com/?q=scapy+dhcp
 

> Thanks!

Silence is hard to parse