Re: [dmarc-ietf] Draft 10 notes: NXDOMAIN

(as participant)

Yes, that's clearly a broken implementation.

I imagine the DMARC document could say it relies on proper implementations
of 8020, but improper ones are known to be in the wild, and results are
unpredictable when these are encountered.  Given the IETF is a standards
organization, one could also argue that this is redundant or superfluous,
but it's probably also harmless.

-MSK

On Mon, Jun 27, 2022 at 2:37 PM Douglas Foster <
dougfoster.emailstandards@gmail.com> wrote:

> My testing was done more than a year ago.   My recollection is that I
> discovered it based on something in the wild, and then confirmed it with a
> locally-configured experiment.   This time I am having trouble finding
> examples.
>
> The only one I can verify is from a previous email exchange on this forum:
>
> mail.foodnetwork.com
> returns NXDOMAIN
>
> but
> _dmarc.mail.foodnetwork.com
> returns DATA for type=TXT
>
> On Mon, Jun 27, 2022 at 9:52 AM Todd Herr <todd.herr@valimail.com> wrote:
>
>> On Sun, Jun 26, 2022 at 1:27 PM Douglas Foster <
>> dougfoster.emailstandards@gmail.com> wrote:
>>
>>> Our draft references and repeats RFC 8020, which asserts that
>>>
>>> "when a DNS resolver receives a response with a response code of
>>> NXDOMAIN, it means that the domain name which is thus denied AND ALL THE
>>> NAMES UNDER IT do not exist."
>>>
>>> My testing indicates that this is not correct.   NXDOMAIN means that no
>>> resource records exist for the specified domain name.  The domain may
>>> contain subdomain nodes which may contain resource records.
>>>
>>> My testing performed on Windows.
>>>
>>> Can someone else test this and report your results?
>>>
>>>
>> It might help further the discussion if you were to favor the rest of us
>> with the examples you used.
>>
>> Specifically, for which domain name did you query and received an
>> NXDOMAIN response, and for which subdomain node of that domain did you
>> query and receive resource record(s) in return?
>> --
>>
>> *Todd Herr * | Technical Director, Standards and Ecosystem
>> *e:* todd.herr@valimail.com
>> *m:* 703.220.4153
>>
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