MIF Working Group Z. Cao Internet-Draft D. Deng Intended status: Informational China Mobile Expires: August 5, 2010 February 2010 IP Family Selection for MIF Host draft-cao-mif-ifs-00 Abstract This document attempts to summarize the problems that are not addressed by current default address selection algorithms. 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 August 5, 2010. Copyright Notice Copyright (c) 2010 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 (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. Code Components extracted from this document must Cao & Deng Expires August 5, 2010 [Page 1] Internet-Draft MIF IP Family Selection February 2010 include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Problem Summary . . . . . . . . . . . . . . . . . . . . . . . . 4 2.1. Amendment #1 . . . . . . . . . . . . . . . . . . . . . . . 4 2.2. Amendment #2 . . . . . . . . . . . . . . . . . . . . . . . 4 3. Security Considerations . . . . . . . . . . . . . . . . . . . . 5 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6 5. Normative References . . . . . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 8 Cao & Deng Expires August 5, 2010 [Page 2] Internet-Draft MIF IP Family Selection February 2010 1. Introduction Default Address Selection algorithms defined in RFC3484 specify default behavior for all IPv6 implementations. RFC3484 implicitly assumes that the IP address is fully in accordence with the applications. Specificly, if the host chooses an IPv6 address, it assumes that there will be IPv6 applications on it. But this assumptions may be invalid during the IPv6 migration. For example, the host is only assigned an IPv6 prefix and it generates a fake IPv4 address to use its IPv4 application. In this case, if the server is IPv4 only, applications invoking gethostbyname() will return only a A record, and the source address selection algorithm will prefer the IPv4 address because they are the same IP family. If there is no host translation module such as BIA [I-D.huang-bia-bis] BIS [I-D.huang-bis-bis] or PNAT [I-D.huang-behave-pnat] on the host, this default behavior will result into the communication failure. This document attempts to summarize the problems that are not addressed by current default address selection algorithms. Cao & Deng Expires August 5, 2010 [Page 3] Internet-Draft MIF IP Family Selection February 2010 2. Problem Summary 2.1. Amendment #1 A simple workaround way to this problem is introduced in this section. We suggest the DNS64 should handle A request normally. So dual stack host will be able to receive both A and AAAA response from DNS64, and then destination address selection policy will take effect and host will select IPv4 address for communication. +-----------+-----------+-----------+-----------+-------------------+ | APPS | Address | Network | Service | Default behavior | +-----------+-----------+-----------+-----------+-------------------+ | v4 | v4v6 | v6 | v4 | failure | +-----------+-----------+-----------+-----------+-------------------+ | v4 | v4v6 | v6 | v4v6 | failure | +-----------+-----------+-----------+-----------+-------------------+ | v4 | v4v6 | v6 | v6 | failure | +-----------+-----------+-----------+-----------+-------------------+ | v4v6 | v4v6 | v4v6 | v4 | NAT64 | +-----------+-----------+-----------+-----------+-------------------+ | v4v6 | v4v6 | v4v6 | v4v6 | NAT64 | +-----------+-----------+-----------+-----------+-------------------+ Figure 1: IP Family Selection 2.2. Amendment #2 RFC3484 should consider the effect of non-meaningful IPv4 address (in PNAT [I-D.huang-behave-pnat]) and IANA assigned shared IPv4 address in GI-DS-Lite [I.D-GI-DSL]. Cao & Deng Expires August 5, 2010 [Page 4] Internet-Draft MIF IP Family Selection February 2010 3. Security Considerations TBD. Cao & Deng Expires August 5, 2010 [Page 5] Internet-Draft MIF IP Family Selection February 2010 4. IANA Considerations This document does not require any IANA actions. Cao & Deng Expires August 5, 2010 [Page 6] Internet-Draft MIF IP Family Selection February 2010 5. Normative References [DNS64] Bagnulo, M., "DNS64: DNS extensions for Network Address Translation from IPv6 Clients to IPv4 Servers", December 2009, . [DNS64-Config] Wing, D., "DNS64 Resolvers and Dual-Stack Hosts", Oct 2009, . [I-D.huang-behave-pnat] Huang, B. and H. Deng, "Prefix NAT: Host based IPv6 translation", December 2009, . [I-D.huang-bia-bis] Huang, B., Deng, H., and T. Savolainen, "Dual Stack Hosts Using "Bump-in-the-API" (BIA)", October 2009, . [I-D.huang-bis-bis] Huang, B., Deng, H., and T. Savolainen, "Dual Stack Hosts using the "Bump-In-the-Stack" Technique (BIS)", October 2009, . [I.D-GI-DSL] Brockners, F. and S. Gundavelli, "Gateway Initiated Dual- Stack Lite Deployment", December 2009, . Cao & Deng Expires August 5, 2010 [Page 7] Internet-Draft MIF IP Family Selection February 2010 Authors' Addresses Zhen Cao China Mobile Unit2, 28 Xuanwumenxi Ave,Xuanwu District Beijing 100053 China Email: zehn.cao@gmail.com Dapeng Liu China Mobile Unit2, 28 Xuanwumenxi Ave,Xuanwu District Beijing 100053 China Email: liudapeng@chinamobile.com Cao & Deng Expires August 5, 2010 [Page 8]