Deprecating int domains: Deprecating Infrastructure "int" Domains
Retiring old internet infrastructure names from the int domain.
Davies, K. and A. Baber, "Deprecating Infrastructure "int" Domains", RFC 9121, DOI 10.17487/RFC9121, April 2023, <https://www.rfc-editor.org/info/rfc9121>.
@misc{rfc9121,
series = {Request for Comments},
number = 9121,
howpublished = {RFC 9121},
publisher = {RFC Editor},
doi = {10.17487/RFC9121},
url = {https://www.rfc-editor.org/info/rfc9121},
author = {K. Davies and A. Baber},
title = {{Deprecating Infrastructure "int" Domains}},
pagetotal = 6,
year = 2023,
month = apr,
} RFC text
Contents
Internet Engineering Task Force (IETF) K. Davies
Request for Comments: 9121 A. Baber
Obsoletes: 1528 IANA
Updates: 1706 April 2023
Category: Informational
ISSN: 2070-1721
Deprecating Infrastructure "int" Domains
Abstract
This document deprecates the use of any "int" domain names that were
designated for infrastructure purposes by the IETF, and it identifies
them for removal from the "int" top-level domain. Any
implementations that involve these domains are now deprecated. This
document also changes the status of RFC 1528 and RFC 1706 to
Historic.
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
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). Not all documents
approved by the IESG are candidates for any level of Internet
Standard; see 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/rfc9121.
Copyright Notice
Copyright (c) 2023 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
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Trust Legal Provisions and are provided without warranty as described
in the Revised BSD License.
Table of Contents
1. Introduction
2. Historical Infrastructural Uses
2.1. atma.int
2.2. ip4.int
2.3. ip6.int
2.4. nsap.int
2.5. rdi.int
2.6. reg.int
2.7. tpc.int
3. Updates to Other RFC Series Documents
3.1. RFC 1528
3.2. RFC 1706
4. IANA Considerations
5. Security Considerations
6. Additional Information
7. Informative References
Acknowledgments
Authors' Addresses
1. Introduction
The "int" top-level domain [RFC1591] is a specialized domain
designated for intergovernmental organizations, which are
organizations established by international treaties between or among
national governments.
Historically, the "int" domain was also used for purposes related to
Internet infrastructure. This practice ended in 2001 when the "arpa"
domain was declared the appropriate home for infrastructural
identifier spaces [RFC3172]. In conjunction with this change, the
eligibility for "int" domains was limited to only intergovernmental
treaty organizations.
The documented uses of infrastructural identifiers in the "int"
domain were largely experimental and are now, in practice, obsolete.
This document changes the status of related specifications to
Historic, and it removes any associated delegations from the "int"
zone in the domain name system.
2. Historical Infrastructural Uses
The following domains were used for infrastructural identifier
purposes that are now considered historic. Although each of these
names was either delegated or documented at one time, the parties
administering them have long since stopped using them.
2.1. atma.int
The atma.int domain was experimentally defined to implement address
lookups for Asynchronous Transfer Mode (ATM), including ATM End
System Addresses (AESAs) [ANS].
2.2. ip4.int
The ip4.int domain was described as providing an alternative to the
in-addr.arpa domain for mapping host IPv4 addresses to host names.
The in-addr.arpa domain zone continues to be administered for this
purpose [RFC1035].
2.3. ip6.int
The ip6.int domain was originally delegated for mapping host IPv6
addresses to host names. It was subsequently removed from the "int"
zone, having been replaced by ip6.arpa [RFC4159].
2.4. nsap.int
The nsap.int domain name was specified to experimentally map Open
Systems Interconnection (OSI) Network Service Access Points to domain
names [RFC1706].
2.5. rdi.int
The rdi.int domain name experimentally mapped OSI Inter-Domain
Routing Protocol's Routing Domain Identifiers [ISO10747] to the
domain name system.
2.6. reg.int
The reg.int domain name hosted an experimental mechanism for
publishing IANA registration values in the domain name system.
2.7. tpc.int
The tpc.int domain name hosted an experimental remote printing
service that served as a gateway between Internet mail and facsimile
transmission [RFC1528].
3. Updates to Other RFC Series Documents
3.1. RFC 1528
The specification for tpc.int [RFC1528] is Historic, as it no longer
functions as described in the document.
3.2. RFC 1706
The specification for nsap.int [RFC1706] is Historic, as it no longer
functions as described in the document.
4. IANA Considerations
IANA has removed the historical "int" domains discussed in this
document.
5. Security Considerations
Some old systems might have one or more subdomains of these names
hardwired and expect a positive response for at least the second-
level domain. This is, of course, true for any name in the DNS and
should not be the sole basis for retaining obsolete names.
Existing applications should eliminate any reliance upon these zones.
The operator of the "int" domain should be cautious about any
potential re-use of these domains for intergovernmental treaty
organizations.
6. Additional Information
This document is the result of a comprehensive inventory of .int
domains to accurately establish and record their purpose based on
historical documentation. As part of this inventory, IANA studied
the domains delegated for purposes related to infrastructure
identifiers. Query patterns in the DNS for these domains were
analyzed and judged to be insignificant; preliminary outreach to the
contacts for the associated domains was conducted. The assessment
concluded that these domains are very likely obsolete. This document
formalizes that assessment.
There are a small number of nominal "int" domains for "international
databases" that are not defined by any standards documentation. They
are assigned to entities rather than for identifier purposes. Their
dispositions are beyond the scope of this memo.
7. Informative References
[ANS] The ATM Forum Technical Committee, "ATM Name System
Specification Version 1.0", ATM Forum af-saa-0069.000,
November 1996, <https://www.broadband-
forum.org/technical/download/af-saa-0069.000.pdf>.
[ISO10747] ISO/IEC, "Information technology - Telecommunications and
information exchange between systems - Protocol for
exchange of inter-domain routeing information among
intermediate systems to support forwarding of ISO 8473
PDUs", ISO/IEC 10747:1994, October 1994,
<https://www.iso.org/standard/21417.html>.
[RFC1035] Mockapetris, P., "Domain names - implementation and
specification", STD 13, RFC 1035, DOI 10.17487/RFC1035,
November 1987, <https://www.rfc-editor.org/info/rfc1035>.
[RFC1528] Malamud, C. and M. Rose, "Principles of Operation for the
TPC.INT Subdomain: Remote Printing -- Technical
Procedures", RFC 1528, DOI 10.17487/RFC1528, October 1993,
<https://www.rfc-editor.org/info/rfc1528>.
[RFC1591] Postel, J., "Domain Name System Structure and Delegation",
RFC 1591, DOI 10.17487/RFC1591, March 1994,
<https://www.rfc-editor.org/info/rfc1591>.
[RFC1706] Manning, B. and R. Colella, "DNS NSAP Resource Records",
RFC 1706, DOI 10.17487/RFC1706, October 1994,
<https://www.rfc-editor.org/info/rfc1706>.
[RFC3172] Huston, G., Ed., "Management Guidelines & Operational
Requirements for the Address and Routing Parameter Area
Domain ("arpa")", BCP 52, RFC 3172, DOI 10.17487/RFC3172,
September 2001, <https://www.rfc-editor.org/info/rfc3172>.
[RFC4159] Huston, G., "Deprecation of "ip6.int"", BCP 109, RFC 4159,
DOI 10.17487/RFC4159, August 2005,
<https://www.rfc-editor.org/info/rfc4159>.
Acknowledgments
This document was compiled with help from Ted Hardie and Michelle
Cotton, with additional input from Jari Arkko, John Klensin, Warren
Kumari, Pete Resnick, George Michaelson, and Toerless Eckert.
Authors' Addresses
Kim Davies
Internet Assigned Numbers Authority
PTI/ICANN
12025 Waterfront Drive
Los Angeles, CA 90094
United States of America
Email: kim.davies@iana.org
Amanda Baber
Internet Assigned Numbers Authority
PTI/ICANN
12025 Waterfront Drive
Los Angeles, CA 90094
United States of America
Email: amanda.baber@iana.org
AI ELI5
On this page
§1Why the int Domain Was Cleaned Up
The int top-level domain is a specialized naming space reserved for intergovernmental organizations established by international treaties. However, in the early days of the internet, this domain was also used experimentally for infrastructure purposes—ways the internet plumbing identified itself in the domain name system.
In 2001, RFC 3172 established that the arpa domain was the proper home for such infrastructure identifiers. This policy change meant no new int domains could be created for infrastructure, but the old experimental ones remained. Over time, the organizations using them stopped, and these domains became obsolete. This document formally deprecates them.
The int domain was an old experimental playground for internet infrastructure names, but it was declared off-limits for that purpose in 2001. Now we are officially closing down the unused old experiments.
§2The Seven Deprecated Domains
The RFC lists seven infrastructure int subdomains that are now deprecated:
- atma.int — experimental address lookups for Asynchronous Transfer Mode (ATM) end systems
- ip4.int — an alternative to in-addr.arpa for mapping IPv4 addresses to names (in-addr.arpa is still in use)
- ip6.int — originally delegated for IPv6 address mapping, but replaced by ip6.arpa and removed from the int zone
- nsap.int — experimental mapping of Open Systems Interconnection (OSI) Network Service Access Points to domain names
- rdi.int — experimental mapping of OSI routing domain identifiers
- reg.int — hosted an experimental mechanism for publishing IANA registration values in DNS
- tpc.int — hosted an experimental remote printing service bridging email and facsimile transmission
Although each was either delegated or documented at some point, the parties administering them stopped using them long ago.
There were seven old experimental address systems hidden under the int domain—for ATM, IPv4, IPv6, OSI protocols, and a fax service. None of them work anymore because the organizations that set them up abandoned them decades ago.
§3Security and Cleanup Implications
Some old systems might have these domain names hardwired in their configuration and expect a positive DNS response. However, this is true for any obsolete name in DNS and should not be sufficient reason to keep them. Existing applications should eliminate any reliance on these zones.
The operator of the int domain should be cautious about any potential re-use of these domain names for legitimate intergovernmental treaty organizations, as the old registrations may create confusion or conflicts. The RFC notes that IANA has formally removed all delegations for these historical int domains from the DNS.
Some very old programs might look for these domains and get confused when they disappear, but that's okay because those programs should have been updated long ago. The cleanup also means nobody can accidentally reuse these names and cause confusion.
§4Formal Status Changes
This document changes the status of two related RFCs to Historic:
- RFC 1528 (the specification for tpc.int and its remote printing service) is now Historic.
- RFC 1706 (the specification for nsap.int and DNS NSAP resource records) is now Historic.
The int domain is now reserved exclusively for intergovernmental treaty organizations, and the arpa domain remains the proper home for internet infrastructure identifier spaces.
Two old instruction manuals for these systems are officially put on the shelf as "history"—they still exist for reference if someone wants to understand what we tried, but they do not describe anything that currently works.