Re: [DNSOP] [dns-operations] dnsop-any-notimp violates the DNS standards

Paul Wouters <paul@nohats.ca> Tue, 17 March 2015 13:34 UTC

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Date: Tue, 17 Mar 2015 09:34:36 -0400 (EDT)
From: Paul Wouters <paul@nohats.ca>
To: Yunhong Gu <guu@google.com>
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Cc: Michael Sinatra <michael@brokendns.net>, dnsop <dnsop@ietf.org>
Subject: Re: [DNSOP] [dns-operations] dnsop-any-notimp violates the DNS standards
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On Tue, 17 Mar 2015, Yunhong Gu wrote:

> The reason that this response can be used for an amplification attack is its size, not the ANY type. A responses
> with 200 A records can be used for the same purpose. The (even deeper) root cause is the use of UDP in DNS protocol.
> I just do not think banning ANY touches any of these fundamental issues.

Right, so require tcp or eastlake cookies, or allow padding the ANY
request so the request/response ratio is close to 1 before allowing
the answer. Make the dig command default to tcp. That should cover
the vast majority of valid ANY queries.

Paul