Network Working Group                                            P. Koch
Internet-Draft                                                   M. Sanz
Intended status: Informational                                  DENIC eG
Expires: September 8, 2011                                 March 7, 2011

                  Changing DNS Operators under DNSSEC


   Changing the DNS delegation for a DNS zone is quite involved if done
   by the books, but most often handled pragmatically in today's
   operational practice at the top level with registries and registrars.
   This document describes a proposal for a delegation change procedure
   that will maintain consistency and validation under DNSSEC.

Status of this Memo

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

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   This Internet-Draft will expire on September 8, 2011.

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Table of Contents

   1.          Introduction  . . . . . . . . . . . . . . . . . . . . . 3
   1.1.        Purpose of this Document  . . . . . . . . . . . . . . . 3
   2.          Requirements for Seamless Operator Change . . . . . . . 3
   3.          Security Considerations . . . . . . . . . . . . . . . . 4
   4.          IANA Considerations . . . . . . . . . . . . . . . . . . 4
   5.          References  . . . . . . . . . . . . . . . . . . . . . . 5
   5.1.        Normative References  . . . . . . . . . . . . . . . . . 5
   5.2.        Informative References  . . . . . . . . . . . . . . . . 5
   Appendix A. Document Revision History . . . . . . . . . . . . . . . 6
   A.1.        Initial document  . . . . . . . . . . . . . . . . . . . 6
               Authors' Addresses  . . . . . . . . . . . . . . . . . . 6

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1.  Introduction

   When the NS RRSet in a DNS delegation is to be changed from one to a
   disjoint other, the conservative approach has been to add the new
   servers as (stealth) secondary servers, then add them to the NS
   RRSet, change the primary master (that is, change the AXFR/IXFR
   source for all the secondary servers), remove the old name servers'
   names from the NS RRSet and finally cease service on those former
   name servers.  This would involve two changes to the zone file for
   the apex NS RRSet and in turn two interactions with the parent zone
   (the registry) for the delegation NS RRSet.

   Operational practice deviates from this in many cases, especially
   where there is a combined role of the registrar as registrar, DNS
   operator and web hoster.  Often the new infrastructure is set up
   independent of and in parallel to the old one and there is only one
   delegation change.  Resolvers will access either version of the DNS
   zone and the inconsistency in DNS data and even at the application
   layer will be tolerated as long as the end user gets to see any
   result at all.

   DNSSEC is less tolerant to this inconsistency, and the challenge is
   that access to and validation of DNS data will involvce multiple
   steps.  The resolver might access DNS data through one (say, the old)
   name server infrastructure and DNS key material (the apex DNSKEY
   RRSet) through the other.  A hard switch would increase the
   likelyhood of a validation failure, should the signature over some
   RRSet not match any key in the DNSKEY RRset.

1.1.  Purpose of this Document

   This document attempts to list requirements for a seamless change of
   DNS operators in a registry/registrar environment.  It then suggests
   a procedure that should work in an automated environment even for
   large numbers of DNS operator changes.  It is meant as a supplement
   or contribution to the updated version of [RFC4641], as currently
   expressed in [I-D.ietf-dnsop-rfc4641bis], section 4.3.5.

2.  Requirements for Seamless Operator Change

   Regardless of the the particular registry provisioning protocol
   (e.g., EPP, [RFC5930], [RFC5931]) DNS registries usually provide for
   a method to transfer a domain name between different registrars.
   However, from this angle there is no separate role for the DNS
   operator, the entity that is responsible for the DNS infrastructure
   and/or the content of the DNS zone.  This entity may be identical to
   the registrar, the registrant, or neither.  From the DNSSEC

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   perspective it is important to consider the entity controlling the
   ZSK and KSK in any transfer that involves changing the NS RRSet to a
   disjoint set (as opposed to simple additions to or removals from the
   NS RRSet).

   The change of a registrar is of limited effect from the DNSSEC
   perspective.  The discussion of the ability of the gaining registrar
   to accept DNSSEC information within a domain object is beyond the
   scope of this document.  The focus is kept on the change of the DNS
   operator.  There are two cases: ideally, the losing operator will be
   able to incorporate data generated by the gaining operator into their
   version of the DNS zone.  However, the proposed solution should also
   be able to cover the case where this cooperation cannot be relied

   This is a preliminary list of requirements for the operator change:

   no private keys  Private cryptographic keys will not be exchanged
      between the losing and the gaining operator.  Scenarios in which
      this would be feasible would not pose the challenges addressed in
      this document.

   little interaction  To ease automation the number of interactions
      between registry, registrar or registrars and operators should be

   no direct channel  We do not assume the existence of a direct,
      confidential, authenticated communication channel between the
      losing and the gaining operator.  On an abstract level, the
      registrant could be viewed as an indirect channel, but involving
      the registrant is not necessarily easily automated.

   little overhead for losing operator  Whenever interaction or action
      cannot be avoided, the losing operator should be involved as
      little as possible to avoid overhead for the leaving customer.  In
      turn, this suggests the gaining operator should be in control of
      the process.

3.  Security Considerations

   This section needs more work

4.  IANA Considerations

   This document does not request any IANA action.

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5.  References

5.1.  Normative References

   [RFC1034]  Mockapetris, P., "Domain names - concepts and facilities",
              STD 13, RFC 1034, November 1987.

   [RFC1035]  Mockapetris, P., "Domain names - implementation and
              specification", STD 13, RFC 1035, November 1987.

   [RFC2606]  Eastlake, D. and A. Panitz, "Reserved Top Level DNS
              Names", BCP 32, RFC 2606, June 1999.

   [RFC5735]  Cotton, M. and L. Vegoda, "Special Use IPv4 Addresses",
              BCP 153, RFC 5735, January 2010.

5.2.  Informative References

              Kolkman, O., "DNSSEC Operational Practices, Version 2",
              draft-ietf-dnsop-rfc4641bis-05 (work in progress),
              October 2010.

   [RFC4033]  Arends, R., Austein, R., Larson, M., Massey, D., and S.
              Rose, "DNS Security Introduction and Requirements",
              RFC 4033, March 2005.

   [RFC4034]  Arends, R., Austein, R., Larson, M., Massey, D., and S.
              Rose, "Resource Records for the DNS Security Extensions",
              RFC 4034, March 2005.

   [RFC4035]  Arends, R., Austein, R., Larson, M., Massey, D., and S.
              Rose, "Protocol Modifications for the DNS Security
              Extensions", RFC 4035, March 2005.

   [RFC4641]  Kolkman, O. and R. Gieben, "DNSSEC Operational Practices",
              RFC 4641, September 2006.

   [RFC5930]  Shen, S., Mao, Y., and NSS. Murthy, "Using Advanced
              Encryption Standard Counter Mode (AES-CTR) with the
              Internet Key Exchange version 02 (IKEv2) Protocol",
              RFC 5930, July 2010.

   [RFC5931]  Harkins, D. and G. Zorn, "Extensible Authentication
              Protocol (EAP) Authentication Using Only a Password",
              RFC 5931, August 2010.

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Appendix A.  Document Revision History

   This section is to be removed should the draft be published.
   $Id: draft-koch-dnsop-dnssec-operator-change.xml,v 1.1 2011/03/07 21:52:05 pk Exp $

A.1.  Initial document


Authors' Addresses

   Peter Koch
   Kaiserstrasse 75-77
   Frankfurt  60329

   Phone: +49 69 27235 0
   Email: pk@DENIC.DE

   Marcos Sanz
   Kaiserstrasse 75-77
   Frankfurt  60329

   Phone: +49 69 27235 0
   Email: sanz@DENIC.DE

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