[Dnsmasq-discuss] Cannot assign IPv6 address for /96 subnet

[Sheng Yang]

Hi Simon,

Any chance you can reproduce it?

If dhcp-range can accept a prefix rather than 64 then hand it out, I
think dhcp-host should also able to do so...

--Sheng

On Wed, Feb 20, 2013 at 2:58 AM, Simon Kelley <simon at thekelleys.org.uk> wrote:
> On 20/02/13 02:16, Sheng Yang wrote:
>> Hi Simon,
>>
>> Did you use dhcphost option? dhcp-range works for me(if I specify a
>> range), but not with dhcp-host option(when I specify dhcp-range as
>> static).
>
> Ah, no, I didn't. I should have read back through the thread. I'll check
> again, but it rather looks like this is non possible, by design,  (or
> miss-design)
>
> Simon.
>
>>
>> --Sheng
>>
>> On Tue, Feb 19, 2013 at 1:06 PM, Simon Kelley <simon at thekelleys.org.uk> wrote:
>>> So, I did some testing. I configured an server interface with prefix-length
>>> 96, and configured dnsmasq with a dhcp-range and 96 prefix.
>>>
>>> Using dhclient, I got a lease successfully.
>>>
>>> The only problem is that dhclient configured the client's interface with
>>> prefix-length 64.
>>>
>>> I moment's thought shows that this is expected: there is nowhere in the
>>> DHCPv6 messages for the prefix-length information to be passed to the
>>> client. There _is_ a prefix-length field in router-advertisements. but
>>> AFAIK, there's no way for the DHCPv6 client to use that information.
>>>
>>> Of course if you're using RA for address-allocation, using SLAAC, the prefix
>>> length has to be 64 anyway.
>>>
>>> If anyone knows better, or can explain how the standard(s) are supposed to
>>> work, please enlighten me.
>>>
>>> Simon.
>>
>