[Doh] EDNS UDP Payload size cache issue

bert hubert <bert.hubert@powerdns.com> Wed, 06 June 2018 12:13 UTC

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Date: Wed, 6 Jun 2018 14:12:58 +0200
From: bert hubert <bert.hubert@powerdns.com>
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Subject: [Doh] EDNS UDP Payload size cache issue
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Hi,

The draft suggests zeroing the DNS ID field to make sure queries can be
cached. One other field that needs to be made constant is the EDNS payload
size. If a client requests DNSSEC, there will always be such a field, but it
has no meaning over DOH. So it can safely be set to zero.

Suggested text for insertion near the end of "5.1 The HTTP Request":

   Similarly, if an EDNS payload size is specified, it SHOULD be set to 0 in
   every DNS request, as this field has no meaning within this protocol.

Bert.