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Re: [DNSOP] Working Group Last Call draft-ietf-dnsop-refuse-any

Tony Finch <dot@dotat.at> Thu, 08 December 2016 11:26 UTC

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Date: Thu, 08 Dec 2016 11:25:04 +0000
From: Tony Finch <dot@dotat.at>
To: Stephane Bortzmeyer <bortzmeyer@nic.fr>
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Cc: Matthijs Mekking <matthijs@pletterpet.nl>, dnsop@ietf.org
Subject: Re: [DNSOP] Working Group Last Call draft-ietf-dnsop-refuse-any
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Stephane Bortzmeyer <bortzmeyer@nic.fr> wrote:
>
> Why not also when cookies are used? Like TCP, they protect against
> reflection attacks.

My reason for deploying minimal-any was not for direct reflection
attacks, because RRL already deals with direct reflection attacks.

I wanted to avoid sending truncated UDP responses to legit resolvers.

When lots of legit recursive resolvers are being attacked with ANY queries
for one of my zones, I don't want them to hammer my authoritative servers
with TCP connections. So, minimal-any means they go away happy with a
small answer, and everything stays on UDP.

Eventually I expect legit resolvers to deploy cookies, and I still want
to send them small answers to avoid TCP when an ANY attack happens.

Tony.
-- 
f.anthony.n.finch  <dot@dotat.at>  http://dotat.at/  -  I xn--zr8h punycode
Forties, Cromarty, Forth: Southwest 5 or 6, decreasing 4 at times. Slight or
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