Re: [dmarc-ietf] Consensus Sought - Ticket #47 (Removal of "pct" tag) - With Interim Notes
Alessandro Vesely <vesely@tana.it> Thu, 03 June 2021 11:07 UTC
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From: Alessandro Vesely <vesely@tana.it>
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Subject: Re: [dmarc-ietf] Consensus Sought - Ticket #47 (Removal of "pct" tag) - With Interim Notes
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On Thu 03/Jun/2021 05:45:33 +0200 Murray S. Kucherawy wrote: > I don't understand what "demeaning a domain's policy" means. I meant to say that p=quarantine; pct=0 is to be considered a strict policy to all effects. Saying so should prevent reasoning something like "Oh, they said quarantine, but since pct=0 it is somewhat faked, so I'll skip X", where X could be rewriting From:, displaying a BIMI image, record aggregate data, or any other action that might depend on the policy. That is to say pct=0 does not alter the value of p=, otherwise testing becomes a nightmare. Perhaps my point would be obvious if the protocol allowed floating point values. Setting pct=1e-37 would have effects equivalent to pct=0, and setting a boundary somewhere to distinguish what is valid from what is not would show up all of its arbitrariness. Best Ale -- > On Fri, May 28, 2021 at 10:20 AM Alessandro Vesely <vesely@tana.it> wrote: >> On Fri 28/May/2021 17:43:37 +0200 Todd Herr wrote: >>> >>> Consensus on Ticket #47 <https://trac.ietf.org/trac/dmarc/ticket/47> >>> (Removal of "pct" tag) was reached during the May 27 DMARC Interim to >>> keep the tag, but to rewrite its definition in whole or in part to make >>> its usage better understood. >> >> >> I think the text in RFC 7489 is quite good. Perhaps a word could be added >> for pct=0; for example: >> >> OLD >> pct: (plain-text integer between 0 and 100, inclusive; OPTIONAL; >> default is 100). Percentage of messages from the Domain Owner's >> mail stream to which the DMARC policy is to be applied. However, >> this MUST NOT be applied to the DMARC-generated reports, all of >> which must be sent and received unhindered. The purpose of the >> "pct" tag is to allow Domain Owners to enact a slow rollout >> enforcement of the DMARC mechanism. The prospect of "all or >> nothing" is recognized as preventing many organizations from >> experimenting with strong authentication-based mechanisms. See >> Section 6.6.4 for details. Note that random selection based on >> this percentage, such as the following pseudocode, is adequate: >> >> if (random mod 100) < pct then >> selected = true >> else >> selected = false >> >> NEW >> pct: (plain-text integer between 0 and 100, inclusive; OPTIONAL; >> default is 100). Percentage of messages from the Domain Owner's >> mail stream to which the DMARC policy is to be applied. However, >> this MUST NOT be applied to any other use, such as skipping DMARC >> reports or demeaning a domain's policy. The purpose of the >> "pct" tag is to allow Domain Owners to enact a slow rollout >> enforcement of the DMARC mechanism. Using this tag, organizations >> can experiment with strong authentication-based mechanisms while >> lowering or even voiding the risk of non-delivery. See Section >> 6.6.4 >> for details. Note that random selection based on this percentage, >> such as the following pseudocode, is adequate: >> >> if (random mod 100) < pct then >> selected = true >> else >> selected = false >> >> jm2c >> Ale >> -- >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> _______________________________________________ >> dmarc mailing list >> dmarc@ietf.org >> https://www.ietf.org/mailman/listinfo/dmarc >> > > > _______________________________________________ > dmarc mailing list > dmarc@ietf.org > https://www.ietf.org/mailman/listinfo/dmarc >
- [dmarc-ietf] Consensus Sought - Ticket #47 (Remov… Todd Herr
- Re: [dmarc-ietf] Consensus Sought - Ticket #47 (R… Alessandro Vesely
- Re: [dmarc-ietf] Consensus Sought - Ticket #47 (R… Steven M Jones
- Re: [dmarc-ietf] Consensus Sought - Ticket #47 (R… Murray S. Kucherawy
- Re: [dmarc-ietf] Consensus Sought - Ticket #47 (R… Alessandro Vesely
- Re: [dmarc-ietf] Consensus Sought - Ticket #47 (R… John Levine
- Re: [dmarc-ietf] Consensus Sought - Ticket #47 (R… Dotzero
- Re: [dmarc-ietf] Consensus Sought - Ticket #47 (R… Tim Wicinski
- Re: [dmarc-ietf] Consensus Sought - Ticket #47 (R… Todd Herr