[Dnsmasq-discuss] SUCCESS

[Simon Kelley]

On 17/10/12 14:54, Gene Czarcinski wrote:

> OK, I believe I understand: as you describe it, this is needed for
> dhcp4. However, getting a little more understanding of how dhcp6 works
> from my last round of debugging, dhcp6 currently does handle multiple
> packets. It filters on the IPv6 subnet specified in --dhcp-range and
> will only serve dhcp6-packets coming in on the interface which has the
> defined dhcp-range subnet. If you specify more than one subnet for a
> specific dnsmasq, then it will serve each. Any --interface or
> --listen-address is irrelevant. However, the two exclude lists are not
> irrelevant and any interface specified in wither of those lists will
> block the service.

The problem is that, without SO_BINDTODEVICE, there is no guarantee that 
the kernel will route DHCP (v4 or v6) packets to the correct instance of 
dnsmasq, when there is more than one.
>
> Now, I assume that all dhcmasq instantiations will each get copies of
> all dhcp6 packets. It is their responsibility to process or drop a
> packet depending on just what they service.

See above: not a valid assumption.
>
]

Cheers,

Simon.