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Independent Submission                                         J. LevineRequest for Comments: 7085                          Taughannock NetworksCategory: Informational                                       P. HoffmanISSN: 2070-1721                                Cybersecurity Association                                                           December 2013Top-Level Domains That Are Already DotlessAbstract   Recent statements from the Internet Architecture Board (IAB) and the   Internet Corporation of Assigned Names and Numbers (ICANN) Security   and Stability Advisory Committee have focused on the problems that   the DNS is likely to experience with top-level domains (TLDs) that   contain address records (so-called "dotless domains").  In order to   help researchers determine the extent of the issues with dotless   domains, this document lists the current dotless TLDs and gives a   script for finding them.  This document lists data about dotless TLDs   but does not address the policy and technology issues other than to   point to the statements of others.Status of This Memo   This document is not an Internet Standards Track specification; it is   published for informational purposes.   This is a contribution to the RFC Series, independently of any other   RFC stream.  The RFC Editor has chosen to publish this document at   its discretion and makes no statement about its value for   implementation or deployment.  Documents approved for publication by   the RFC Editor are not a candidate for any level of Internet   Standard; seeSection 2 of RFC 5741.   Information about the current status of this document, any errata,   and how to provide feedback on it may be obtained athttp://www.rfc-editor.org/info/rfc7085.Levine & Hoffman              Informational                     [Page 1]

RFC 7085                  Already Dotless TLDs             December 2013Copyright Notice   Copyright (c) 2013 IETF Trust and the persons identified as the   document authors.  All rights reserved.   This document is subject toBCP 78 and the IETF Trust's Legal   Provisions Relating to IETF Documents   (http://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.Table of Contents1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .22.  Current Dotless Domains . . . . . . . . . . . . . . . . . . .32.1.  TLDs with A Records . . . . . . . . . . . . . . . . . . .32.2.  TLDs with AAAA Records  . . . . . . . . . . . . . . . . .32.3.  TLDs with MX Records  . . . . . . . . . . . . . . . . . .43.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .44.  Security Considerations . . . . . . . . . . . . . . . . . . .55.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .56.  Informative References  . . . . . . . . . . . . . . . . . . .5Appendix A.  Script for Finding Dotless Domains . . . . . . . . .61.  Introduction   In the past few years, well-respected groups have issued documents   about top-level domains in the DNS that contain address records   (so-called "dotless domains").  The Security and Stability Advisory   Committee (SSAC) of the Internet Corporation for Assigned Names and   Numbers (ICANN) issued a report called "Report on Dotless Domains"   [SAC053] in February 2012.  The Internet Architecture Board (IAB)   issued a statement called "Dotless Domains Considered Harmful"   [IAB-DOTLESS] in July 2013.  The New gTLD Program Committee of the   ICANN Board of Directors (NGPC) approved a resolution on dotless   domains [NGPC-DOTLESS] in August 2013.  (The authors of this document   note that they are not on the SSAC, the IAB, or the ICANN Board.)   All of these documents consider the effects of dotless domains   without describing the extent of their current deployment.  In order   to help researchers determine the extent of the problems with dotless   domains, this document lists the known dotless domains at the time of   publication and shows how researchers can find them in the future.   In this document, we consider any TLD with an A, AAAA, and/or MX   record at the apex to be dotless.  This document is meant to provide   current data to the Internet community but does not give advice.Levine & Hoffman              Informational                     [Page 2]

RFC 7085                  Already Dotless TLDs             December 2013   Many people have expressed a belief that ICANN prohibits all TLDs   from being dotless.  That belief is not true; ICANN's policies apply   only to their contracted TLDs.  This document shows the extent to   which dotless domains exist today.2.  Current Dotless Domains   This section shows the dotless domains we found on September 3, 2013,   using the script inAppendix A.  The data was nearly constant for   many months, with very few additions or deletions of records.   We checked every TLD in the root zone to see which ones had A, AAAA,   or MX records.  We found that about 5% of the TLDs did, and all of   the TLDs that do are two-letter TLDs or country code TLDs (which are   also known as ccTLDs).2.1.  TLDs with A Records   At the time this document is published, the following TLDs have A   records.   AC has address 193.223.78.210   AI has address 209.59.119.34   CM has address 195.24.205.60   DK has address 193.163.102.24   GG has address 87.117.196.80   IO has address 193.223.78.212   je has address 87.117.196.80   KH has address 203.223.32.21   PN has address 80.68.93.100   SH has address 193.223.78.211   TK has address 217.119.57.22   TM has address 193.223.78.213   TO has address 216.74.32.107   UZ has address 91.212.89.8   VI has address 193.0.0.198   WS has address 64.70.19.332.2.  TLDs with AAAA Records   At the time this document is published, the following TLD has an AAAA   record.   DK has IPv6 address 2a01:630:0:40:b1a:b1a:2011:1Levine & Hoffman              Informational                     [Page 3]

RFC 7085                  Already Dotless TLDs             December 20132.3.  TLDs with MX Records   At the time this document is published, the following TLDs have MX   records.  The SSAC report implies, but does not explicitly say, that   MX records would cause a TLD to be considered dotless; the IAB report   does not mention MX records at all.   AI mail is handled by 10 mail.offshore.AI.   AX mail is handled by 5 mail.aland.net.   CF mail is handled by 0 mail.intnet.CF.   DM mail is handled by 10 mail.nic.DM.   GP mail is handled by 10 ns1.worldsatelliteservices.com.   GP mail is handled by 5 ns1.nic.GP.   GT mail is handled by 10 ASPMX.L.GOOGLE.COM.   GT mail is handled by 20 ALT1.ASPMX.L.GOOGLE.COM.   GT mail is handled by 20 ALT2.ASPMX.L.GOOGLE.COM.   GT mail is handled by 30 ASPMX2.GOOGLEMAIL.COM.   GT mail is handled by 30 ASPMX3.GOOGLEMAIL.COM.   GT mail is handled by 30 ASPMX4.GOOGLEMAIL.COM.   GT mail is handled by 30 ASPMX5.GOOGLEMAIL.COM.   HR mail is handled by 5 alpha.carnet.HR.   IO mail is handled by 10 mailer2.IO.   KH mail is handled by 10 ns1.dns.net.KH.   KM mail is handled by 100 mail1.comorestelecom.KM.   LK mail is handled by 10 malithi-slt.nic.LK.   LK mail is handled by 20 malithi-lc.nic.LK.   MQ mail is handled by 10 mx1-mq.mediaserv.net.   PA mail is handled by 5 ns.PA.   TT mail is handled by 10 ALT1.ASPMX.L.GOOGLE.COM.   TT mail is handled by 1 ASPMX.L.GOOGLE.COM.   UA mail is handled by 10 mr.kolo.net.   VA mail is handled by 100 raphaelmx3.posta.VA.   VA mail is handled by 10 raphaelmx1.posta.VA.   VA mail is handled by 10 raphaelmx2.posta.VA.   WS mail is handled by 10 mail.worldsite.WS.   YE mail is handled by 10 mail.yemen.net.YE.3.  IANA Considerations   The script inAppendix A relies on IANA continuing to publish a copy   of the TLDs in the root zone at   <http://data.iana.org/TLD/tlds-alpha-by-domain.txt>.Levine & Hoffman              Informational                     [Page 4]

RFC 7085                  Already Dotless TLDs             December 20134.  Security Considerations   This document lists the known dotless domains; it does not express an   opinion whether or not there are security considerations with the   existence of dotless domains.  The referenced IAB and SSAC reports   discuss the opinions of the respective bodies on the security and   stability considerations of dotless domains.5.  Acknowledgements   Andrew Sullivan and Marc Blanchet gave helpful comments on this   document.6.  Informative References   [IAB-DOTLESS]              Internet Architecture Board, "Dotless Domains Considered              Harmful", July 2013, <https://www.iab.org/2013/07/10/iab-statement-dotless-domains-considered-harmful/>.   [NGPC-DOTLESS]              New gTLD Program Committee of the ICANN Board, "Approved              Resolution on Dotless Domains", September 2013,              <http://www.icann.org/en/groups/board/documents/resolutions-new-gtld-13aug13-en.htm>.   [SAC053]   ICANN Security and Stability Advisory Committee, "SSAC              Report on Dotless Domains", February 2012,              <http://www.icann.org/en/groups/ssac/documents/sac-053-en.pdf>.Levine & Hoffman              Informational                     [Page 5]

RFC 7085                  Already Dotless TLDs             December 2013Appendix A.  Script for Finding Dotless Domains   The following Bourne shell script was used for finding the data in   this document.  The authors believe that this script will work   correctly on a wide variety of operating systems and will continue to   do so in the foreseeable future.  As is customary in the current   legal environment, the authors make no assurance that the script is   correct or that the script will not cause damage on a system where it   is run.   The script checks each nameserver for each TLD instead of just doing   a simple query because the nameservers for some of the TLDs have   inconsistent data in them with respect to the records shown here.   #! /bin/sh   # Get the current list of TLDs from IANA   wget -O orig.txthttp://data.iana.org/TLD/tlds-alpha-by-domain.txt   # Remove the comment at the top of the file   grep -v '^#' orig.txt > TLDs.txt   # Get all the nameservers   while read tld; do host -t NS $tld; done < TLDs.txt > TLD-servers.txt   # Do queries for each record type, and do them on each nameserver   for rec in A AAAA MX; do     while read tld ignorea ignoreb ns; do       host -t $rec $tld. $ns;     done < TLD-servers.txt;   done > all-out.txt   # Print the results   grep "has address" all-out.txt | sort -uf   grep "has IPv6" all-out.txt | sort -uf   grep "mail is handled" all-out.txt | sort -ufAuthors' Addresses   John Levine   Taughannock Networks   EMail: standards@taugh.com   Paul Hoffman   Cybersecurity Association   EMail: paul.hoffman@cybersecurity.orgLevine & Hoffman              Informational                     [Page 6]