DNS Query Name Minimisation to Improve Privacy
draft-ietf-dnsop-rfc7816bis-07
Network Working Group S. Bortzmeyer
Internet-Draft AFNIC
Obsoletes: 7816 (if approved) R. Dolmans
Intended status: Standards Track NLnet Labs
Expires: 30 April 2021 P. Hoffman
ICANN
27 October 2020
DNS Query Name Minimisation to Improve Privacy
draft-ietf-dnsop-rfc7816bis-07
Abstract
This document describes a technique called "QNAME minimisation" to
improve DNS privacy, where the DNS resolver no longer always sends
the full original QNAME and original QTYPE 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
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on 30 April 2021.
Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the
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Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
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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 . . . . . . . . . . . . . . 4
2.1. QTYPE Selection . . . . . . . . . . . . . . . . . . . . . 4
2.2. QNAME Selection . . . . . . . . . . . . . . . . . . . . . 5
2.3. Limit Number of Queries . . . . . . . . . . . . . . . . . 5
2.4. Stub and Forwarding Resolvers . . . . . . . . . . . . . . 6
3. Algorithm to Perform QNAME Minimisation . . . . . . . . . . . 7
4. QNAME Minimisation Examples . . . . . . . . . . . . . . . . . 8
5. Performance Considerations . . . . . . . . . . . . . . . . . 9
6. Security Considerations . . . . . . . . . . . . . . . . . . . 10
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 10
7.1. Normative References . . . . . . . . . . . . . . . . . . 10
7.2. Informative References . . . . . . . . . . . . . . . . . 11
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 12
Changes from RFC 7816 . . . . . . . . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13
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.
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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 one of
the authors in January 2015, Paul Mockapetris explained that this
tradition comes from a desire to optimise the number of requests,
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