Providing Minimal-Sized Responses to DNS Queries That Have QTYPE=ANY
RFC 8482
Internet Engineering Task Force (IETF) J. Abley
Request for Comments: 8482 Afilias
Updates: 1034, 1035 O. Gudmundsson
Category: Standards Track M. Majkowski
ISSN: 2070-1721 Cloudflare Inc.
E. Hunt
ISC
January 2019
Providing Minimal-Sized Responses to DNS Queries That Have QTYPE=ANY
Abstract
The Domain Name System (DNS) specifies a query type (QTYPE) "ANY".
The operator of an authoritative DNS server might choose not to
respond to such queries for reasons of local policy, motivated by
security, performance, or other reasons.
The DNS specification does not include specific guidance for the
behavior of DNS servers or clients in this situation. This document
aims to provide such guidance.
This document updates RFCs 1034 and 1035.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc8482.
Abley, et al. Standards Track [Page 1]
RFC 8482 Minimal Responses for ANY Queries January 2019
Copyright Notice
Copyright (c) 2019 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
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described in the Simplified BSD License.
Table of Contents
1. Introduction ....................................................3
1.1. Terminology ................................................3
2. Motivations for Use of ANY Queries ..............................3
3. General Approach ................................................4
4. Behavior of DNS Responders ......................................5
4.1. Answer with a Subset of Available RRsets ...................5
4.2. Answer with a Synthesized HINFO RRset ......................5
4.3. Answer with Best Guess as to Intention .....................6
4.4. Transport Considerations ...................................6
5. Behavior of DNS Initiators ......................................7
6. HINFO Considerations ............................................7
7. Updates to RFCs 1034 and 1035 ...................................7
8. Implementation Experience .......................................8
9. Security Considerations .........................................8
10. IANA Considerations ............................................9
11. References .....................................................9
11.1. Normative References ......................................9
11.2. Informative References ....................................9
Acknowledgements ..................................................10
Authors' Addresses ................................................10
Abley, et al. Standards Track [Page 2]
RFC 8482 Minimal Responses for ANY Queries January 2019
1. Introduction
The Domain Name System (DNS) specifies a query type (QTYPE) "ANY".
The operator of an authoritative DNS server might choose not to
respond to such queries for reasons of local policy, motivated by
security, performance, or other reasons.
The DNS specification [RFC1034] [RFC1035] does not include specific
guidance for the behavior of DNS servers or clients in this
situation. This document aims to provide such guidance.
1.1. Terminology
This document uses terminology specific to the Domain Name System
(DNS), descriptions of which can be found in [RFC8499].
[RFC1035] defined type 255 to be "*". However, DNS implementations
commonly use the keyword "ANY" to refer to that type code; this
document follows that common usage.
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