[Dnsmasq-discuss] Using DUID + IAID for identifying nic with dhcp-host

[Simon Kelley]

On 13/08/13 17:18, Immanuel Klinkenberg wrote:
> Hello,
>
> I successfully configured my openWRT Router for using IPV6 over
> sixxs.net, with stateful (I think it is) dhcpv6 (dnsmasq). Almost
> everything works like a charm. The problem is, that I only can assign
> one IP statically to a computer, because I only can use the DUID or
> hostname for identifying a dhcp-host. Is there an option for using DUID
> and IAID together for identifying a dhcp-host (interface)?
>
> For example like this:
>
> DUID: 00:01:02:03:04:05:06:07:08:09:0a:0b:0c:0d
> IAID: 0123456789
> IP to assign: 2001:1:2:3:4::1
>
> dhcp-host=0123456789,
> id:00:01:02:03:04:05:06:07:08:09:0a:0b:0c:0d,[2001:1:2:3:4::1], infinite
>
>

There's no option to use the IAID directly. A host with two IAIDs 
implies a host with two interfaces, and therefore interfaces on two 
subnets. If that's the case, then you can have two dhcp-host lines for 
the two subnets, and the appropriate one for the subnet will be used.

An example may make this clearer:

If the machine running dnsmasq has two interfaces, one on subnet 
2001:1:2:3:4 and  the other on 2001:5:6:7:8

A client has two interfaces, one on each of the subnets. It has a 
DUID=00:01:02:03:04:05:06:07:08:09:0a:0b:0c:0d and two IAIDs, one for 
each interface.

You can configure


dhcp-host=id:00:01:02:03:04:05:06:07:08:09:0a:0b:0c:0d,\[2001:1:2:3:4::1], 
infinite

dhcp-host=d:00:01:02:03:04:05:06:07:08:09:0a:0b:0c:0d,\[2001:5:6:7:8::1], infinite

and have the correct thing happen.

Does that help?


Cheers,

Simon.