DNSEXT Working Group Lianyuan Li, Internet-Draft Zhenqiang Li, Intended status: Informational Xiaodong Duan, Expires: January 6, 2010 China Mobile July 6, 2009 DNS Extensions to Support IPv4 and IPv6 draft-li-dnsext-ipv4-ipv6-00.txt Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html This Internet-Draft will expire on January 6, 2010. Copyright Notice Copyright (c) 2009 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 (http://trustee.ietf.org/license-info). Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Li Expires January 6, 2010 [Page 1] Internet-Draft DNS Extensions to Support IPv4 and IPv6 July 2009 Abstract There are two kinds of TYPE for host IP address: one is A, the other is AAAA, which records IPv4 and IPv6 addresses respectively. This document defines a new TYPE, which is mainly used in queries in order to get both IPv4 and IPv6 addresses. Li Expires January 6, 2010 [Page 2] Internet-Draft DNS Extensions to Support IPv4 and IPv6 July 2009 1. Introduction 1.1 Current DNS operation There are mainly two resource record types for host IP addresses in the DNS. One is A resource record, the other is AAAA resource record. An A record type is defined to store a host's IPv4 address, an AAAA or A6 is defined to store a host's IPv6 address. 1.2 Problem for current IPv6 DNS operation Due to large-scale applicable for IPv4, it will take a long time to transit from IPv4 to IPv6. During the transition, IPv4 network and IPv6 network will coexist. In most cases, the host will not know whether the address of the other side is IPv4 or IPv6. According to current mechanism, the host will send an AAAA query first. If there is no IPv6 address, then an A query will be sent out. The above mechanism has following disadvantages. First, it will take longer time compared with only A or AAAA query is needed. Second, both A and AAAA query will waste bandwidth, especially the air interface bandwidth. Third, more process resources in host and DNS server are needed. In order to solve the above problems, a new kind of record type is proposed. 2. New resource record definition A new record type mainly used in queries is defined to get the host IPv4 and IPv6 addresses. It is not intended to create new resource record. 2.1 BOTH record type The BOTH resource record type is specific to the Internet class. 2.2 BOTH data format There is no new data format is defined. In fact, it is unnecessary to create new data format. 2.3 BOTH query A BOTH query for a specified domain name in the Internet class returns all associated A and AAAA resource records in the answer section of a response. 2.4 Textual format of BOTH records There is no new textual format for BOTH records. Li Expires January 6, 2010 [Page 3] Internet-Draft DNS Extensions to Support IPv4 and IPv6 July 2009 3. Modifications to existing query types All existing query types that perform type A and AAAA processing must be redefined to perform type A, type AAAA and BOTH processing. These definitions mean that a name server must add any relevant IPv4 addresses and any relevant IPv6 addresses available locally to the response when processing BOTH queries. 4. Security Considerations Any information obtained from the DNS must be regarded as unsafe unless there are some new security mechanism. The definition of the both query type does not change the model for use of these techniques. So, this specification is not believed to cause any new security problems, nor to solve any existing ones. 5. IANA Considerations There are no IANA assignments to be performed. 6. References [1] Mockapetris, P., "Domain Names - Concepts and Facilities", STD 13, RFC 1034, November 1987. [2] Mockapetris, P., "Domain Names - Implementation and Specification", STD 13, RFC 1035, November 1987. [3] Thomson.S, Huitema.C, Ksinant.V, Souissi.M,''DNS Extensions to Support IP Version 6'' RFC 3596, October 2003 Author's Addresses Lianyuan Li China Mobile Unit 2, 28 Xuanwumenxi Ave, Xuanwu District, Beijing 100053, China Email: lilianyuan@chinamobile.com Zhenqiang Li Li Expires January 6, 2010 [Page 4] Internet-Draft DNS Extensions to Support IPv4 and IPv6 July 2009 China Mobile Unit 2, 28 Xuanwumenxi Ave, Xuanwu District, Beijing 100053, China Email: lizhenqiang@chinamobile.com Xiaodong Duan China Mobile Unit 2, 28 Xuanwumenxi Ave, Xuanwu District, Beijing 100053, China Email: duanxiaodong@chinamobile.com Li Expires January 6, 2010 [Page 5]