DNS Push Notifications
RFC 8765
| Document | Type | RFC - Proposed Standard (June 2020; No errata) | |
|---|---|---|---|
| Authors | Tom Pusateri , Stuart Cheshire | ||
| Last updated | 2020-06-22 | ||
| Stream | Internent Engineering Task Force (IETF) | ||
| Formats | plain text html xml pdf htmlized (tools) htmlized bibtex | ||
| Reviews | |||
| Stream | WG state | Submitted to IESG for Publication | |
| Document shepherd | Tim Wicinski | ||
| Shepherd write-up | Show (last changed 2019-05-11) | ||
| IESG | IESG state | RFC 8765 (Proposed Standard) | |
| Action Holders |
(None)
|
||
| Consensus Boilerplate | Yes | ||
| Telechat date | |||
| Responsible AD | Éric Vyncke | ||
| Send notices to | Tim Wicinski <tjw.ietf@gmail.com> | ||
| IANA | IANA review state | IANA OK - Actions Needed | |
| IANA action state | RFC-Ed-Ack | ||
Internet Engineering Task Force (IETF) T. Pusateri
Request for Comments: 8765 Unaffiliated
Category: Standards Track S. Cheshire
ISSN: 2070-1721 Apple Inc.
June 2020
DNS Push Notifications
Abstract
The Domain Name System (DNS) was designed to return matching records
efficiently for queries for data that are relatively static. When
those records change frequently, DNS is still efficient at returning
the updated results when polled, as long as the polling rate is not
too high. But, there exists no mechanism for a client to be
asynchronously notified when these changes occur. This document
defines a mechanism for a client to be notified of such changes to
DNS records, called DNS Push Notifications.
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/rfc8765.
Copyright Notice
Copyright (c) 2020 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
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction
1.1. Requirements Language
1.2. Fatal Errors
2. Motivation
3. Overview
4. State Considerations
5. Transport
6. Protocol Operation
6.1. Discovery
6.2. DNS Push Notification SUBSCRIBE
6.2.1. SUBSCRIBE Request
6.2.2. SUBSCRIBE Response
6.3. DNS Push Notification Updates
6.3.1. PUSH Message
6.4. DNS Push Notification UNSUBSCRIBE
6.4.1. UNSUBSCRIBE Message
6.5. DNS Push Notification RECONFIRM
6.5.1. RECONFIRM Message
6.6. DNS Stateful Operations TLV Context Summary
6.7. Client-Initiated Termination
6.8. Client Fallback to Polling
7. Security Considerations
7.1. Security Services
7.2. TLS Name Authentication
7.3. TLS Early Data
7.4. TLS Session Resumption
8. IANA Considerations
9. References
9.1. Normative References
9.2. Informative References
Acknowledgments
Authors' Addresses
1. Introduction
Domain Name System (DNS) records may be updated using DNS Update
[RFC2136]. Other mechanisms such as a Discovery Proxy [RFC8766] can
also generate changes to a DNS zone. This document specifies a
protocol for DNS clients to subscribe to receive asynchronous
notifications of changes to RRsets of interest. It is immediately
relevant in the case of DNS-based Service Discovery [RFC6763] but is
not limited to that use case; it provides a general DNS mechanism for
DNS record change notifications. Familiarity with the DNS protocol
and DNS packet formats is assumed [RFC1034] [RFC1035] [RFC6895].
1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
1.2. Fatal Errors
Certain invalid situations are described in this specification, such
as a server sending a Push Notification subscription request to a
client, or a client sending a Push Notification response to a server.
These should never occur with a correctly implemented client and
server, and if they do occur, then they indicate a serious
implementation error. In these extreme cases, there is no reasonable
expectation of a graceful recovery, and the recipient detecting the
error should respond by unilaterally aborting the session without
regard for data loss. Such cases are addressed by having an engineer
investigate the cause of the failure and fixing the problem in the
software.
Where this specification says "forcibly abort", it means sending a
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