[Dnsmasq-discuss] Restrict DHCP providing default gateway to *one* host on one network

Simon Kelley simon at thekelleys.org.uk
Wed Apr 24 10:00:59 BST 2013


On 24/04/13 08:58, TJ wrote:
> On 23/04/13 15:33, Will Dennis (Live.com) wrote:
>> interface=vl10-ovsbr0
>> interface=vl20-ovsbr0
>> bind-interfaces
>> dhcp-range=vl10-ovsbr0,192.168.10.50,192.168.10.150,4h
>> dhcp-range=vl20-ovsbr0,192.168.20.50,192.168.20.150,4h
>> dhcp-host=52:54:00:d5:ee:4d,id:*,192.168.10.1
>> dhcp-mac=set:wanem-20,52:54:00:45:8c:6a
>> dhcp-option=vl10-ovsbr0,3,192.168.10.254
>> dhcp-option=tag:vl20-ovsbr0,tag:!wanem-20,3,192.168.20.254
>> log-dhcp
>
> I may be mis-reading the manual but as I understood it dnsmasq will issue a default set of options for
> each range.
>
> dhcp-range=vl20-ovsbr0 will get a default option 3 which will be the IP of the host running dnsmasq
>
> dhcp-mac=set:wanem-20 sets a tag for the exceptional client
>
> dhcp-option=tag:vl20-ovsbr0,tag:!wanem-20 will set a (possibly different) gateway for non-exceptional clients.
>
> At this point the exceptional client will have the default option 3 for the range. I think what you need is to not send any default route at all when the exceptional client makes a request:
>
> dhcp-option=tag:vl20-ovsbr0,tag:wanem-20,3
>

I concur. Will, you've just omitted the empty option 3 from the last 
dhcp-option.

(Wanders off to teach dnsmasq to complain in this situation.......)


Cheers,

Simon.



More information about the Dnsmasq-discuss mailing list