Network Working Group S. Bortzmeyer
Internet-Draft AFNIC
Intended status: Standards Track April 6, 2016
Expires: October 8, 2016

Using DNAME in the root for the delegation of special-use TLDs


This documents asks IANA to add DNAME records in the DNS root for TLDs which are in the Special-Use Domain Names registry, in order to ensure they receive an appropriate reply (NXDOMAIN) and that the root is not too bothered by them.

REMOVE BEFORE PUBLICATION: there is no obvious place to discuss this document. May be the IETF DNSOP (DNS Operations) group, through its mailing list (the author reads it). Or may AS112 operators mailing lists? The source of the document, as well as a list of open issues, is currently kept at Github.

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at

Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."

This Internet-Draft will expire on October 8, 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 ( 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 and background

The DNS root receives a lot of requests for TLDs which do not exist. In the spirit of [RFC7534], it would be good if they could be redirected to a sink such as AS112, to save root's resources. TODO references to one of the many DNS-OARC talks about these junk requests.

Some of these names, and specially one of the biggest offenders, .local ([RFC6762]), are registered in the Special-Use Domain Names registry of [RFC6761]. They are obvious candidates for a delegation to the sink.

It is proposed to use the new AS112, the one described by [RFC7535] to implement this sink.

TODO requires discussion with AS112 people

1.1. Requirements Terminology

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].

2. Rules

Every TLD ([RFC7719], section 2) which is in the Special-Use Domain Names registry ([RFC6761]) SHOULD be delegated by IANA through a DNAME to as described in [RFC7535] if and only if the registration of these TLD say that resolvers should not or must not look them up in the DNS.

It is important to notice that this document does not define a policy to decide if a TLD should be delegated or not. Instead, it relies on the existing Special-Use Domain Names registry and its rules.

RFC-EDITOR: remove before publication. As of today, with these rules, .local ([RFC6762]) or .onion ([RFC7686]) would be delegated but not .example (its registration in [RFC6761] does not define special handling for resolvers) or .home or .belkin (which generate a huge traffic at the root but are not in the Special-Use Domain Names registry.

3. Benefits

The main benefit is less load on the root and a better efficiency of the caches.

TODO mention RFC 6303?

4. Possible issues

TODO support of DNAME (there is certainly a Geoff Huston survey of DNAMEs in the wild).

5. IANA Considerations

IANA is requested (TODO what is the appropriate wording?) to add a DNAME in the root for every TLD which fits the rules of Section 2.

RFC-EDITOR: remove before publication. There is currently no DNAME in the root. It is expected that the creation of the first one will require a top-down, multi-stakeholder, long and complicated process with a lot of meetings, reports by consultants and design teams.

6. Security Considerations

TODO: leaks, privacy. Copy from the AS112 RFC ?

7. Acknowledgments

Thanks to Paul Hoffman to say that it may be a good idea and for Ted Lemon to give the final impulse, with his [I-D.tldr-sutld-ps].

8. References

8.1. Normative References

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997.
[RFC6761] Cheshire, S. and M. Krochmal, "Special-Use Domain Names", RFC 6761, DOI 10.17487/RFC6761, February 2013.
[RFC7534] Abley, J. and W. Sotomayor, "AS112 Nameserver Operations", RFC 7534, DOI 10.17487/RFC7534, May 2015.
[RFC7535] Abley, J., Dickson, B., Kumari, W. and G. Michaelson, "AS112 Redirection Using DNAME", RFC 7535, DOI 10.17487/RFC7535, May 2015.
[RFC7719] Hoffman, P., Sullivan, A. and K. Fujiwara, "DNS Terminology", RFC 7719, DOI 10.17487/RFC7719, December 2015.

8.2. Informative References

[RFC6762] Cheshire, S. and M. Krochmal, "Multicast DNS", RFC 6762, DOI 10.17487/RFC6762, February 2013.
[RFC7686] Appelbaum, J. and A. Muffett, "The ".onion" Special-Use Domain Name", RFC 7686, DOI 10.17487/RFC7686, October 2015.
[I-D.tldr-sutld-ps] Lemon, T. and R. Droms, "Special Use TLD Problem Statement", Internet-Draft draft-tldr-sutld-ps-00, April 2016.

Author's Address

Stephane Bortzmeyer AFNIC 1, rue Stephenson Montigny-le-Bretonneux, 78180 France Phone: +33 1 39 30 83 46 EMail: URI: