Re: [DNSOP] I-D Action: draft-ietf-dnsop-nsec3-guidance-02.txt

Vladimír Čunát <> Fri, 26 November 2021 11:30 UTC

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From: Vladimír Čunát <>
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Subject: Re: [DNSOP] I-D Action: draft-ietf-dnsop-nsec3-guidance-02.txt
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I like the text and how it's improving.

> Note that a validating resolver MUST still validate the signature over 
> the NSEC3 record to ensure the iteration count was not altered since 
> record publication (see {{RFC5155}} section 10.3).
It might be better to clarify that this "MUST" does not really apply to 
the SERVFAIL case.  (The text around has changed recently.)

I think this SERVFAIL will generally be best implemented by simply 
ignoring any NSEC3 above the corresponding limit.  Maybe I'd even 
standardize the case that way, but I don't care really. It's an 
advantage unstated in the draft that this is very easy to do, leaving no 
room for bugs (e.g. unintentional downgrade opportunities).