[Dnsmasq-discuss] dhcp-range interface feature (I was using it)

[Simon Kelley]

On 07/11/12 00:00, Colin Ligertwood wrote:
> I figured that was the case. Thanks, Simon. My only concern is
> accounting for an edge case where the DHCP server would push a range of
> addresses not on the interface. Unlikely, but theoretically possible, no?

I think it's theoretically possible within the DHCP spec,(the server has 
to have an IP address which is routable from the client, but RFC 2131 
section 4.1 doesn't say it _has_ to be on the same subnet.)

It's not and never has been possible for dnsmasq. The alterations to 
dhcp-range have not changed this.

Cheers,

Simon.

>
> Cheers!
> Colin.
>
>
> On Tue, Nov 6, 2012 at 3:55 PM, Simon Kelley <simon at thekelleys.org.uk
> <mailto:simon at thekelleys.org.uk>> wrote:
>
>     On 06/11/12 23:53, Colin Ligertwood wrote:
>
>         Hi All
>
>         First, let me say how much I love dnsmasq. Thanks everyone for
>         the great
>         work done on it. It has become the new standard in dns/dhcp
>         service on
>         network appliances.
>
>         The changelog states that the interface: flag of the dhcp-range
>         feature
>         was removed in 2.63 because nobody was using it, and its syntax was
>         semantically displeasing.
>
>         I'm working with a team on a network appliance product which
>         used the
>         interface feature of the dhcp-range flag to segregate different
>         dhcp-ranges to different interfaces (obviously). In the
>         changelog, it
>         also states that the feature has become obsolete. If that's
>         true, how do
>         I replicate the same functionality of segregating the serving of
>         different dhcp-ranges to different interfaces?
>
>
>     You don't need to: dnsmasq will automatically use the correct
>     dhcp-range for the correct interface based on IP addresses.
>
>     Any range whose start and end addresses fall into a subnet where the
>     interface has an IP address in that subnet is considered, any one
>     which doesn't, is ignored.
>
>
>     You should use --interface and/or --except-interface as access
>     control to eliminate DHCP requests on network segments where you
>     don't want to provide any service, but you don't need to worry about
>     associating dhcp ranges to network interfaces.
>
>
>     Cheers,
>
>     Simon.
>
>
>
>
>         I'm running Openbsd 5.1.
>
>         Cheers, and thanks!
>
>
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