Special Use Domain Name 'ipv4only.arpa'
RFC 8880
Document | Type |
RFC - Proposed Standard
(August 2020; No errata)
Updates RFC 7050
Was draft-cheshire-sudn-ipv4only-dot-arpa (individual)
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Authors | Stuart Cheshire , David Schinazi | ||
Last updated | 2020-08-31 | ||
Stream | Internent Engineering Task Force (IETF) | ||
Formats | plain text html xml pdf htmlized (tools) htmlized bibtex | ||
Reviews | |||
Stream | WG state | (None) | |
Document shepherd | Warren Kumari | ||
Shepherd write-up | Show (last changed 2020-01-19) | ||
IESG | IESG state | RFC 8880 (Proposed Standard) | |
Action Holders |
(None)
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Consensus Boilerplate | Yes | ||
Telechat date | |||
Responsible AD | Warren Kumari | ||
Send notices to | (None) | ||
IANA | IANA review state | Version Changed - Review Needed | |
IANA action state | RFC-Ed-Ack |
Internet Engineering Task Force (IETF) S. Cheshire Request for Comments: 8880 Apple Inc. Updates: 7050 D. Schinazi Category: Standards Track Google LLC ISSN: 2070-1721 August 2020 Special Use Domain Name 'ipv4only.arpa' Abstract NAT64 (Network Address and Protocol Translation from IPv6 Clients to IPv4 Servers) allows client devices using IPv6 to communicate with servers that have only IPv4 connectivity. The specification for how a client discovers its local network's NAT64 prefix (RFC 7050) defines the special name 'ipv4only.arpa' for this purpose. However, in its Domain Name Reservation Considerations section (Section 8.1), that specification (RFC 7050) indicates that the name actually has no particularly special properties that would require special handling. Consequently, despite the well-articulated special purpose of the name, 'ipv4only.arpa' was not recorded in the Special-Use Domain Names registry as a name with special properties. This document updates RFC 7050. It describes the special treatment required and formally declares the special properties of the name. It also adds similar declarations for the corresponding reverse mapping names. 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/rfc8880. 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. Conventions and Terminology 2. Reasons to Declare 'ipv4only.arpa' as Special 3. Consequences of 'ipv4only.arpa' Not Being Declared Special 3.1. Consequences for Name Resolution APIs and Libraries 3.2. Consequences for DNS64 Implementations 4. Remedies 5. Security Considerations 6. IANA Considerations 7. Domain Name Reservation Considerations 7.1. Special Use Domain Name 'ipv4only.arpa' 7.2. Names '170.0.0.192.in-addr.arpa' and '171.0.0.192.in-addr.arpa' 7.2.1. ip6.arpa Reverse Mapping PTR Records 8. References 8.1. Normative References 8.2. Informative References Appendix A. Example BIND 9 Configuration Acknowledgements Authors' Addresses 1. Introduction NAT64 (Network Address and Protocol Translation from IPv6 Clients to IPv4 Servers) [RFC6146] allows client devices using IPv6 to communicate with servers that have only IPv4 connectivity. DNS64 (DNS Extensions for Network Address Translation from IPv6 Clients to IPv4 Servers) [RFC6147] facilitates use of NAT64 by clients by generating synthesized IPv6 addresses for IPv4 servers that have no IPv6 address of their own, or by communicating the local network's NAT64 prefix to clients so that they can perform the IPv6 address synthesis themselves. The specification for how a client discovers its local network's NAT64 prefix [RFC7050] defines the special name 'ipv4only.arpa' for this purpose, but in its Domain Name Reservation Considerations section (Section 8.1), that specification [RFC7050] indicates that the name actually has no particularly special properties that would require special handling and does not request IANA to record the name in the Special-Use Domain Names registry [SUDN]. Consequently, despite the well-articulated special purpose of the name, 'ipv4only.arpa' was not recorded in the Special-Use Domain Names registry [SUDN] as a name with special properties. This omission was discussed in the document "Special-Use Domain Names Problem Statement" [RFC8244]. As a result of this omission, in cases where software needs to give this name special treatment in order for it to work correctly, thereShow full document text