[Dnsmasq-discuss] dnsmasq listening on 0.0.0.0

[Simon Kelley]

richardvoigt at gmail.com wrote:
>>  DHCP that always binds the wildcard - doing otherwise _may_ be possible,
>>  but be prepared for much testing and strange behaviour. For instance,
>>  you need to be able to receive packets whose destination address in
>>  255.255.255.255.
> 
> But the DHCP socket is (or can be with a config file setting) bound to
> a particular interface, even if not a particular IP, correct?

At kernel level, it's not bound to anything. Dnsmasq sees DHCP packets
which arrive on all interfaces. The first thing it does is to filter
them based on --interface --except-interface and --no-dhcp-interface.
Anything which doesn't pass the filter is thrown away with no action.

The OP wants to be have the kernel do the filtering. There's no
practical benefit to doing that in most cases.

Cheers,

Simon.