Client Subnet in DNS Queries
draft-ietf-dnsop-edns-client-subnet-07
dnsop C. Contavalli
Internet-Draft W. van der Gaast
Intended status: Informational Google
Expires: September 22, 2016 D. Lawrence
Akamai Technologies
W. Kumari
Google
March 21, 2016
Client Subnet in DNS Queries
draft-ietf-dnsop-edns-client-subnet-07
Abstract
This document describes an EDNS0 extension that is in active use to
carry information about the network that originated a DNS query, and
the network for which the subsequent response can be cached. Since
it has some known operational and privacy shortcomings, a revision
will be worked through the IETF for improvement.
Status of This Memo
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provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on September 22, 2016.
Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
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publication of this document. Please review these documents
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Contavalli, et al. Expires September 22, 2016 [Page 1]
Internet-Draft Client Subnet in DNS Queries March 2016
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Privacy Note . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Requirements Notation . . . . . . . . . . . . . . . . . . . . 4
4. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
5. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 6
6. Option Format . . . . . . . . . . . . . . . . . . . . . . . . 7
7. Protocol Description . . . . . . . . . . . . . . . . . . . . 8
7.1. Originating the Option . . . . . . . . . . . . . . . . . 8
7.1.1. Recursive Resolvers . . . . . . . . . . . . . . . . . 8
7.1.2. Stub Resolvers . . . . . . . . . . . . . . . . . . . 9
7.1.3. Forwarding Resolvers . . . . . . . . . . . . . . . . 9
7.2. Generating a Response . . . . . . . . . . . . . . . . . . 10
7.2.1. Authoritative Nameserver . . . . . . . . . . . . . . 10
7.2.2. Intermediate Nameserver . . . . . . . . . . . . . . . 12
7.3. Handling ECS Responses and Caching . . . . . . . . . . . 13
7.3.1. Caching the Response . . . . . . . . . . . . . . . . 13
7.3.2. Answering from Cache . . . . . . . . . . . . . . . . 14
7.4. Delegations and Negative Answers . . . . . . . . . . . . 15
7.5. Transitivity . . . . . . . . . . . . . . . . . . . . . . 16
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17
9. DNSSEC Considerations . . . . . . . . . . . . . . . . . . . . 17
10. NAT Considerations . . . . . . . . . . . . . . . . . . . . . 17
11. Security Considerations . . . . . . . . . . . . . . . . . . . 18
11.1. Privacy . . . . . . . . . . . . . . . . . . . . . . . . 18
11.2. Birthday Attacks . . . . . . . . . . . . . . . . . . . . 19
11.3. Cache Pollution . . . . . . . . . . . . . . . . . . . . 20
12. Sending the Option . . . . . . . . . . . . . . . . . . . . . 21
12.1. Probing . . . . . . . . . . . . . . . . . . . . . . . . 21
12.2. Whitelist . . . . . . . . . . . . . . . . . . . . . . . 22
13. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
14. Contributing Authors . . . . . . . . . . . . . . . . . . . . 24
15. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 24
16. References . . . . . . . . . . . . . . . . . . . . . . . . . 25
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