Operational Guidelines for DNS Transport in Mixed IPv4/IPv6 Environments

Metadata

Publisher: IETF
Doc Type: Best Practice
Pages: 17
Abstract: This document provides guidelines and documents best current practice for operating authoritative DNS servers, recursive resolvers, and stub resolvers in a mixed IPv4/IPv6 environment. This document recommends that both authoritative DNS servers and recursive resolvers support IPv4 and IPv6. It also provides guidance on how recursive DNS resolvers should select upstream DNS servers, including when IPv4-embedded IPv6 addresses are available. This document obsoletes RFC 3901.
Publication Date: 2026-08-01
Status Note: Best Current Practice
DOI: 10.17487/RFC10001
Link: https://doi.org/10.17487/RFC10001
Author(s): Momoka Yamamoto
Tobias Fiebig
Keyword(s): DNS, IPv6

Latest version of IETF RFC 10001

Document Versions — IETF RFC 10001

▶ IETF RFC 10001 (2026-08-01)

THIS DOC [ACTIVE] [LATEST VERSION]

Normative Reference(s)

IETF RFC 1034 [Active*]
IETF RFC 1035 [Active, Amended*]
IETF RFC 2119 [Active*]
IETF RFC 4291 [Active*]
IETF RFC 4821 [Active*]
IETF RFC 6052 [Active*]
IETF RFC 6724 [Active*]
IETF RFC 6891 [Active*]
IETF RFC 7766 [Active*]
IETF RFC 8174 [Active*]
IETF RFC 8200 [Active*]
IETF RFC 8899 [Active*]
IETF RFC 9210 [Active*]
IETF RFC 9293 [Active*]
IETF RFC 9471 [Active*]
RFC9715 — RFC9715 EXTERNAL

Bibliographic Reference(s)

10.1007-978-3-031-28486-1_22 — V6DNSRDY-23 EXTERNAL
10.1145-3730567.3764439 — DNSv6MTU EXTERNAL
IETF.draft-ietf-dnsop-ns-revalidation-13 — I-D.ietf-dnsop-ns-revalidation EXTERNAL
RIPE NCC, "The RIPE NCC has run out of IPv4 Addresses", November 2019, <https://www.ripe.net/publications/news/about-ripe-ncc-and-ripe/the-ripe-ncc-has-run-out-of-ipv4-addresses>. EXTERNAL
"resolv.conf(5) - Linux manual page", 2025, <https://man7.org/linux/man-pages/man5/resolv.conf.5.html>. EXTERNAL
"DNS flag day 2020", <https://dnsflagday.net/2020/>. EXTERNAL
IANA, "Technical requirements for authoritative name servers", <https://www.iana.org/help/nameserver-requirements>. EXTERNAL
IETF RFC 1918 [Active*]
IETF RFC 2131 [Active*]
IETF RFC 2182 [Active*]
IETF RFC 2460 [Superseded*]
IETF RFC 3542 [Active*]
IETF RFC 3901 [Superseded*]
IETF RFC 4034 [Active*]
IETF RFC 4193 [Active*]
RFC6146 — RFC6146 EXTERNAL
RFC6540 — RFC6540 EXTERNAL
RFC6877 — RFC6877 EXTERNAL
RFC6888 — RFC6888 EXTERNAL
RFC7050 — RFC7050 EXTERNAL
RFC7269 — RFC7269 EXTERNAL
RFC7858 — RFC7858 EXTERNAL
IETF RFC 8106 [Active*]
IETF RFC 8201 [Active*]
RFC8781 — RFC8781 EXTERNAL
RFC8900 — RFC8900 EXTERNAL
RFC9250 — RFC9250 EXTERNAL
RFC9313 — RFC9313 EXTERNAL
RFC9386 — RFC9386 EXTERNAL
IETF RFC 9499 [Active*]
RFC9872 — RFC9872 EXTERNAL
IETF RFC 9915 [Active*]

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IETF RFC 10001, Operational Guidelines for DNS Transport in Mixed IPv4/IPv6 Environments. Available at https://doi.org/10.17487/RFC10001

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<span class="citation"><cite>IETF RFC 10001</cite>, Operational Guidelines for DNS Transport in Mixed IPv4/IPv6 Environments. Available at <a href="https://doi.org/10.17487/RFC10001" target="_blank" rel="noopener">https://doi.org/10.17487/RFC10001</a></span>

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IETF RFC 10001, Operational Guidelines for DNS Transport in Mixed IPv4/IPv6 Environments
doi: 10.17487/RFC10001
url: https://doi.org/10.17487/RFC10001

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<li>
<cite id="bib-rfc10001">IETF RFC 10001</cite>, Operational Guidelines for DNS Transport in Mixed IPv4/IPv6 Environments
<span class="doi">10.17487/RFC10001</span>
</li>