DNS Query Name Minimisation to Improve Privacy
draft-ietf-dnsop-rfc7816bis-06
Network Working Group S. Bortzmeyer
Internet-Draft AFNIC
Obsoletes: 7816 (if approved) R. Dolmans
Intended status: Standards Track NLnet Labs
Expires: 1 April 2021 P. Hoffman
ICANN
28 September 2020
DNS Query Name Minimisation to Improve Privacy
draft-ietf-dnsop-rfc7816bis-06
Abstract
This document describes techniques called "QNAME minimisation" to
improve DNS privacy, where the DNS resolver no longer always sends
the full original QNAME to the upstream name server. This document
obsoletes RFC 7816.
This document is part of the IETF DNSOP (DNS Operations) Working
Group. The source of the document, as well as a list of open issues,
is at <https://framagit.org/bortzmeyer/rfc7816-bis>
Status of This Memo
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This Internet-Draft will expire on 1 April 2021.
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Bortzmeyer, et al. Expires 1 April 2021 [Page 1]
Internet-Draft QNAME Minimisation September 2020
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Table of Contents
1. Introduction and Background . . . . . . . . . . . . . . . . . 2
1.1. Experience From RFC 7816 . . . . . . . . . . . . . . . . 3
1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
2. Description of QNAME Minimisation . . . . . . . . . . . . . . 3
3. Algorithm to Perform Aggressive Method QNAME Minimisation . . 5
4. QNAME Minimisation Examples . . . . . . . . . . . . . . . . . 6
5. Limit Number of Queries . . . . . . . . . . . . . . . . . . . 7
6. Performance Considerations . . . . . . . . . . . . . . . . . 9
7. Security Considerations . . . . . . . . . . . . . . . . . . . 9
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
8.1. Normative References . . . . . . . . . . . . . . . . . . 9
8.2. Informative References . . . . . . . . . . . . . . . . . 10
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 11
Changes from RFC 7816 . . . . . . . . . . . . . . . . . . . . . . 11
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12
1. Introduction and Background
The problem statement for this document is described in [RFC7626].
This specific solution is not intended to fully solve the DNS privacy
problem; instead, it should be viewed as one tool amongst many.
QNAME minimisation follows the principle explained in Section 6.1 of
[RFC6973]: the less data you send out, the fewer privacy problems
you have.
Before QNAME minimisation, when a resolver received the query "What
is the AAAA record for www.example.com?", it sent to the root
(assuming a resolver whose cache is empty) the very same question.
Sending the full QNAME to the authoritative name server was a
tradition, not a protocol requirement. In a conversation with the
author in January 2015, Paul Mockapetris explained that this
tradition comes from a desire to optimise the number of requests,
when the same name server is authoritative for many zones in a given
name (something that was more common in the old days, where the same
name servers served .com and the root) or when the same name server
is both recursive and authoritative (something that is strongly
discouraged now). Whatever the merits of this choice at this time,
the DNS is quite different now.
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