Subject: Re: [dmarc-ietf] Clarifying the value of arc.closest-fail

From: "Kurt Andersen (b)" <[email-masked]>
Date: Wed, 3 Jan 2018 22:50:01 +0000

While I wait for Bron's confirmation that my understanding matches his (see
email from yesterday), on Wed, Jan 3, 2018 at 8:57 PM, Seth Blank <
[email-masked]> wrote:

>
> . . .text for . . . arc.closest-fail . . .
>

I'm uncomfortable with the terminology implied by the term
"arc.closest-fail". I think that it is more "ams.closest-fail" or
"arc.ams-broken". AMS is expected to not verify except in the most recent
ARC set. Doing so is not in any way a "failure" and has no bearing on the
validity of the ARC chain (as documented in the cv parameter). Opinions
regarding a replacement term?

--Kurt

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From: Seth Blank <[email-masked]>
Date: Wed, 03 Jan 2018 23:00:22 +0000

> regarding a replacement term?

My strong preference is this be tracked and the considerstions therein
referenced in Experimental Considerations. I have no strong preference what
we actually call it.

I’m fine with ams.cb for “closest break” if that keeps things nice and tidy
for an A-R (i.e. arc=pass ams.cb=1).

I also like it because then we have arc cv and ams cb. But I’m splitting
hairs, and again, don’t really care what it’s called.

---

From: Bron Gondwana <[email-masked]>
Date: Thu, 04 Jan 2018 10:09:34 +1100

On Thu, 4 Jan 2018, at 09:50, Kurt Andersen (b) wrote:
> While I wait for Bron's confirmation that my understanding matches his
> (see email from yesterday),
I'll go check on that...

> on Wed, Jan 3, 2018 at 8:57 PM, Seth Blank <[email-masked]> wrote:>> 
> I'm uncomfortable with the terminology implied by the term "arc.closest-
> fail". I think that it is more "ams.closest-fail" or "arc.ams-broken".
> AMS is expected to not verify except in the most recent ARC set. Doing
> so is not in any way a "failure" and has no bearing on the validity of
> the ARC chain (as documented in the cv parameter). Opinions regarding
> a replacement term?

Happy for the terminology to change.  amc.closest-fail might be better.
An analogy might be that each AMS casts a shadow of legitimacy forwards
a certain length.  While the AMS still holds, you know that the things
it covers are unchanged since the step that signed it.  That's really
valuable to know.
To give a clear english description for what I want, it is "Oldest AMS
which is still valid".  I don't care what it's called, or if it is "oldest-
valid" or "newest-invalid" or whatever, so long as the thing I do care
about can be accurately extracted.
 I'd also like to know the bootstrap pre-ARC case, which thankfully AAR
 contains as dkim=pass, spf=pass, etc.  While dkim=pass is still true,
 we know it wasn't modified by the first ARC signer either.
Bron.

--
  Bron Gondwana, CEO, FastMail Pty Ltd
  [email-masked]

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From: "Murray S. Kucherawy" <[email-masked]>
Date: Fri, 5 Jan 2018 00:16:53 -0500

On Wed, Jan 3, 2018 at 5:50 PM, Kurt Andersen (b) <[email-masked]> wrote:

> (see email from yesterday), on Wed, Jan 3, 2018 at 8:57 PM, Seth Blank <

I would prefer "arc.*" to "ams.*", because all of the registered examples
name the protocol from which the information is being taken.  But the text
describing "ptype" allows for either, so it's only a preference.

-MSK