DHCPv6 and DDNS

[Philippe Clérié]

On 06/29/2015 10:22 PM, Shawn Routhier wrote:
>
>> On Jun 29, 2015, at 5:05 PM, Philippe Clérié <philippe at gcal.net> wrote:
>>
>> On 06/29/2015 04:53 PM, Simon Hobson wrote:
>>> Chris Buxton <clists at buxtonfamily.us> wrote:
>>>
>>>>> It took a while but I believe I have found my problem. It appears that the DHCP server does not update DNS records for static leases. DNS does get updated for clients that get their addresses from the subnet range.
>>>>>
>>>>> Can anyone confirm that please?
>>>>
>>>> Correct, that is the default behavior. It can be changed with a configuration option. Iirc, the option is called "update-static-leases".
>>>
>>> Just for completeness, be aware that IIRC it will create the DNS entries but doesn't delete them. That's because a static lease (host declaration with fixed-address statement) doesn't create a lease record, so the server actually has no comprehension of the "lease" expiring.
>>>
>>>
>
> The server currently doesn’t do DDNS updates for v6 static leases with or without the update-static-leases option enabled.
>
> <snip>
>
>>
>> For what it's worth, there are more problems.
>>
>> - There's a race condition with DAD (There's a work around for that, but it was supposed to have been fixed - in Debian.).
>>
>> - DHCPv4 and v6 don't seem to agree on what DUID each is using (not sure what the story is on that. It's not a priority presently.)
>
> This is addressed in 4.3.x. You would need to set the ddns-update-stype to “standard” and to have your clients form their DUID
> and client-id correctly and consistently.
>
>>
>> - I'm now trying out updates from the client (just adding "allow client-updates" to the server configuration), and my client just hangs on boot, never replying to the Advertise message from the server. Investigation is ongoing.
>>
>> Regards,
>>
>> --
>> Philippe
>>
>> ------
>> The trouble with common sense it that it is so uncommon.
>> <Anonymous>
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>
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I was also working under the assumption that DDNS updates for static 
leases worked in v6 with update-static-leases enabled.

That turns out to be incorrect according to the man page for dhcpd.conf 
(Debian 4.3.1). It is specifically stated that this only works for the 
interim update style. Since I am using standard style, it may well be 
that the behavior I am seeing is as intended. So I think that pursuing 
this is a waste of time. And I've already spent far too much time on 
just this one issue for the past few weeks.

So I'll just go fill in my DNS zones with static entries and be done 
with it.

Thanks for the replies and the help.

-- 
Philippe

------
The trouble with common sense it that it is so uncommon.
<Anonymous>