Re: [DNSOP] NSEC/NSEC3 for unsigned zones and aggressive use

"Peter van Dijk" <peter.van.dijk@powerdns.com> Fri, 21 July 2017 23:47 UTC

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From: "Peter van Dijk" <peter.van.dijk@powerdns.com>
To: dnsop@ietf.org
Date: Sat, 22 Jul 2017 01:47:21 +0200
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Subject: Re: [DNSOP] NSEC/NSEC3 for unsigned zones and aggressive use
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On 20 Jul 2017, at 17:00, Stephane Bortzmeyer wrote:

> draft-ietf-dnsop-nsec-aggressiveuse is more aggressive (because it can
> now synthetizes answers) so it seems to me the same reasons should
> apply?

That it is more aggressive, -and- that it relies on a feature of DNSSEC, 
suggests that we SHOULD be stricter here, and the only interpretation of 
‘stricter’ I can imagine is requiring DNSSEC.

However, I have advocated (offline) in the past for allowing unsigned 
NSEC to be used to deter PRSD attacks, allowing the resolver to reduce 
queries to the targeted auth by >90% - a win for both sides. It is a 
tricky balance. If somebody is under attack, that surely is the worst 
time for them to upload a DS, while enabling DNSSEC on their end (which 
would come with RRSIGs that validators then ignore) as a mitigation 
strategy that actually works, would be wonderful to have.

Kind regards,
-- 
Peter van Dijk
PowerDNS.COM BV - https://www.powerdns.com/