inconsistent ddns behaviour

[Glenn Satchell]

ddns-update-style none; turns ddns updates off globally, probably not what
you want. ddns-update-style is a global setting, so you can't do different
styles for different hosts or subnets.

You can add ddns-updates off; in a subnet to disable ddns for that subnet.

See dhcpd.conf man page for details.

regards,
-glenn

On Mon, March 27, 2017 5:56 pm, Simon Hobson wrote:
> Rick Dicaire <kritek at gmail.com> wrote:
>
>> There is no zone directive in the subnet declaration. Why are ddns
>> updates being sent for that subnet?
>
> Did you read what I wrote - a zone declaration is NOT required other than
> to specify the key to be used :
>
>> > Is this expected behaviour?
>>
>> Yes.
>> The default is to lookup the SOA record for the appropriate zones to
>> find the master DNS server, and send updates (unsigned) to that. Thus
>> with a correctly configured DNS, updates will be generated automagically
>> without any admin intervention.
>> However, using unsigned updates is considered insecure - and so you
>> should be specifying DNS zones - not to indicate the master DNS, but to
>> specify the signing key.
>
> If you want no DDNS updates then you have to specify that you don't want
> them, with (IIRC) a ddns-update-<something> declaration (either globally
> or in a particular subnet).
>
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