Network Working Group M. Boucadair Internet-Draft C. Jacquenet Intended status: Standards Track France Telecom Expires: April 23, 2010 D. Cheng Huawei Y. Lee Comcast October 20, 2009 Multi-Topology IS-IS for IPv4-mapped IPv6 draft-boucadair-isis-v4v6-mt-01 Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow modifications of such material outside the IETF Standards Process. Without obtaining an adequate license from the person(s) controlling the copyright in such materials, this document may not be modified outside the IETF Standards Process, and derivative works of it may not be created outside the IETF Standards Process, except to format it for publication as an RFC or to translate it into languages other than English. 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 April 23, 2010. Copyright Notice Boucadair, et al. Expires April 23, 2010 [Page 1] Internet-Draft IPv4-mapped IPv6 M-ISIS October 2009 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. Abstract This memo defines two new Multi Topology Routing Identifiers (MT IDs) to be used by the Intermediate System to Intermediate System (M-ISIS, [RFC5120]) routing protocol within a Multi-Topology (MT) context. These new M-ISIS topologies are meant to convey routing information which is specific to IPv4-mapped IPv6 addresses [I-D.ietf-behave-address-format]. The goal of running separate instances for IPv4-mapped IPv6 routes is to isolate the IPv6 routing table from the IPv4 routing table, and to avoid any overload due to the population of the table by IPv4-mapped IPv6 routes. This isolation is motivated also from an operational perspective to enforce specific routing policies for each topology. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119]. Boucadair, et al. Expires April 23, 2010 [Page 2] Internet-Draft IPv4-mapped IPv6 M-ISIS October 2009 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Multi-Topology Reachable IPv4 Mapped IPv6 Prefixes TLV . . . . 4 3. Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. Forwarding . . . . . . . . . . . . . . . . . . . . . . . . . . 5 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5 6. Security Considerations . . . . . . . . . . . . . . . . . . . . 5 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 5 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5 8.1. Normative References . . . . . . . . . . . . . . . . . . . 5 8.2. Informative References . . . . . . . . . . . . . . . . . . 6 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 6 Boucadair, et al. Expires April 23, 2010 [Page 3] Internet-Draft IPv4-mapped IPv6 M-ISIS October 2009 1. Introduction M-ISIS [RFC5120] is a mechanism that has been specified to run within a single IS-IS [RFC1195] domain where various logical IS-IS topologies are deployed, based on several criteria such as the need to differentiate IPv6 topologies from IPv4 topologies. Distinct MT IDs (Multi Topology Identifiers) are assigned by IANA (e.g., MT ID # 0 for standard topology, MT ID # 2 for IPv6 routing topology, etc.). MT ID # 6-#3995 range is reserved for IETF consensus. This document requests the assignment of two new MT IDs for the following usages: o Unicast IPv4-mapped IPv6 IS-IS routing topology; o Multicast IPv4-mapped IPv6 IS-IS routing topology. Within the context of IPv4 address exhaustion and the IPv6-IPv4 interconnection, numerous solutions are being elaborated within IETF. Both translation (e.g., [I-D.ietf-behave-v6v4-xlate-stateful] and [I-D.ietf-behave-v6v4-xlate]) and encapsulation (e.g., [I-D.boucadair-dslite-interco-v4v6] and [I-D.boucadair-behave-ipv6-portrange]) schemes are proposed to facilitate IPv6-IPv4 interconnection. These solutions require the injection of routes to IPv4-mapped IPv6 [I-D.ietf-behave-address-format] destinations in intra-domain routing protocols. In order to prevent any overload of the native IPv6 routing table with IPv4-mapped IPv6 routes, this memo defines new M-ISIS IDs which are required for the activation of multiple M-ISIS topologies, including one topology that is dedicated to IPv4-mapped routing (both unicast and multicast). This is motivated also for operational reasons and to ease the migration to full IPv6. As a result, an unicast IPv4-mapped IPv6 topology may be established and used for unicast IPv4-mapped IPv6 route computation purposes, and a multicast IPv4-mapped IPv6 topology may be established and used for multicast IPv4-mapped IPv6 route computation purposes. 2. Multi-Topology Reachable IPv4 Mapped IPv6 Prefixes TLV No new TLV is required to indicate that the LSP packet conveys IPv4- mapped IPv6 (unicast and multicast, respectively) routes. TLV type 237 [RFC5120] must be used to announce IPv4 mapped IPv6 prefixes. 3. Procedure This document does not require any modification to the procedure Boucadair, et al. Expires April 23, 2010 [Page 4] Internet-Draft IPv4-mapped IPv6 M-ISIS October 2009 specified in [RFC5120]. Nevertheless, only routes to IPv4-mapped IPv6 prefixes MUST be instantiated within an IPv4-mapped IPv6 routing MT. Concretely, the IANA prefix defined in [I-D.ietf-behave-address-format] MUST be supported by default. Service providers MAY also choose a LIR prefix to build the IPv4- mapped IPv6 addresses. 4. Forwarding Only incoming datagrams destined to IPv4-mapped IPv6 addresses are forwarded according to the IPv4-inferred IPv6 routing topology. WKP and/or LIR prefix defined in [I-D.ietf-behave-address-format] MUST be configured in all participating nodes. 5. IANA Considerations This document requests the following IS-IS MT IDs: o MT ID# for unicast IPv4-mapped IPv6 topology o MT ID# for multicast IPv4-mapped IPv6 topology. 6. Security Considerations This document does not introduce any security issue in addition to those defined in [RFC5120]. 7. Acknowledgements TBC 8. References 8.1. Normative References [RFC1195] Callon, R., "Use of OSI IS-IS for routing in TCP/IP and dual environments", RFC 1195, December 1990. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC5120] Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi Topology (MT) Routing in Intermediate System to Boucadair, et al. Expires April 23, 2010 [Page 5] Internet-Draft IPv4-mapped IPv6 M-ISIS October 2009 Intermediate Systems (IS-ISs)", RFC 5120, February 2008. 8.2. Informative References [I-D.boucadair-behave-ipv6-portrange] Boucadair, M., Levis, P., Grimault, J., Villefranque, A., Kassi-Lahlou, M., Bajko, G., Lee, Y., and T. Melia, "Flexible IPv6 Migration Scenarios in the Context of IPv4 Address Shortage", draft-boucadair-behave-ipv6-portrange-03 (work in progress), October 2009. [I-D.boucadair-dslite-interco-v4v6] Boucadair, M., Jacquenet, C., Grimault, J., Kassi-Lahlou, M., Levis, P., Cheng, D., and Y. Lee, "Deploying Dual- Stack lite in IPv6-only Network", draft-boucadair-dslite-interco-v4v6-02 (work in progress), October 2009. [I-D.ietf-behave-address-format] Huitema, C., Bao, C., Bagnulo, M., Boucadair, M., and X. Li, "IPv6 Addressing of IPv4/IPv6 Translators", draft-ietf-behave-address-format-00 (work in progress), August 2009. [I-D.ietf-behave-v6v4-xlate] Li, X., Bao, C., and F. Baker, "IP/ICMP Translation Algorithm", draft-ietf-behave-v6v4-xlate-01 (work in progress), September 2009. [I-D.ietf-behave-v6v4-xlate-stateful] Bagnulo, M., Matthews, P., and I. Beijnum, "NAT64: Network Address and Protocol Translation from IPv6 Clients to IPv4 Servers", draft-ietf-behave-v6v4-xlate-stateful-02 (work in progress), October 2009. Authors' Addresses Mohamed Boucadair France Telecom 3, Av Francois Chateau Rennes, 35000 France Email: mohamed.boucadair@orange-ftgroup.com Boucadair, et al. Expires April 23, 2010 [Page 6] Internet-Draft IPv4-mapped IPv6 M-ISIS October 2009 Christian Jacquenet France Telecom 3, Av Francois Chateau Rennes, 35000 France Email: christian.jacquenet@orange-ftgroup.com Dean Cheng Huawei USA Email: Chengd@huawei.com Yiu L. Lee Comcast USA Email: Yiu_Lee@Cable.Comcast.com Boucadair, et al. Expires April 23, 2010 [Page 7]