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 draft-koch-dnsop-dnssec-operator-change-00 Abstract 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. 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 http://datatracker.ietf.org/drafts/current/. 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Koch & Sanz Expires September 8, 2011 [Page 1] Internet-Draft DNSSEC Operator Change March 2011 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 Koch & Sanz Expires September 8, 2011 [Page 2] Internet-Draft DNSSEC Operator Change March 2011 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 Koch & Sanz Expires September 8, 2011 [Page 3] Internet-Draft DNSSEC Operator Change March 2011 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 upon. 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 minimized. 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. Koch & Sanz Expires September 8, 2011 [Page 4] Internet-Draft DNSSEC Operator Change March 2011 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 [I-D.ietf-dnsop-rfc4641bis] 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. Koch & Sanz Expires September 8, 2011 [Page 5] Internet-Draft DNSSEC Operator Change March 2011 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 DENIC eG Kaiserstrasse 75-77 Frankfurt 60329 DE Phone: +49 69 27235 0 Email: pk@DENIC.DE Marcos Sanz DENIC eG Kaiserstrasse 75-77 Frankfurt 60329 DE Phone: +49 69 27235 0 Email: sanz@DENIC.DE Koch & Sanz Expires September 8, 2011 [Page 6]