Network Working Group M. Boucadair Internet-Draft C. Jacquenet Intended status: Standards Track France Telecom Expires: August 16, 2010 D. Cheng Huawei Y. Lee Comcast February 12, 2010 Multi-Topology/Multi-Instance OSPFv3 for IPv4-Embedded IPv6 draft-boucadair-ospf-v4v6-ospfv3-mt-02 Abstract This memo defines two new Multi Topology Routing Identifiers (MT IDs), based on [I-D.ietf-ospf-mt-ospfv3] and two new Instance Identifiers (MI IDs), based on [I-D.ietf-ospf-af-alt], respectively, in OSPFv3. With these identifiers, an IPv4-Embedded IPv6 topology is maintained for both IPv6 unicast and multicast traffic. The purpose of running separate instances or topologies for IPv4- Embedded IPv6 traffic is to distinguish from the native IPv6 routing topology, and the topology that is used for routing IPv4-Embedded IPv6 datagrams only. Separate instances/topologies are also meant to prevent any overload of the native IPv6 routing tables by IPv4-Embedded IPv6 routes. 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]. 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." Boucadair, et al. Expires August 16, 2010 [Page 1] Internet-Draft IPv4-Embedded Pv6 MT/MI-OSPFv3 February 2010 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 16, 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 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. 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. Boucadair, et al. Expires August 16, 2010 [Page 2] Internet-Draft IPv4-Embedded Pv6 MT/MI-OSPFv3 February 2010 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. IPv4-Embedded IPv6 OSPFv3 Topologies . . . . . . . . . . . . . 4 3. IPv4-Embedded IPv6 OSPFv3 Instances . . . . . . . . . . . . . . 5 4. Provisioning . . . . . . . . . . . . . . . . . . . . . . . . . 5 5. Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 6. Advertising IPv4-Embedded IPv6 Routes . . . . . . . . . . . . . 5 7. Forwarding . . . . . . . . . . . . . . . . . . . . . . . . . . 6 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6 9. Security Considerations . . . . . . . . . . . . . . . . . . . . 7 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 7 11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7 11.1. Normative References . . . . . . . . . . . . . . . . . . . 7 11.2. Informative References . . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 8 Boucadair, et al. Expires August 16, 2010 [Page 3] Internet-Draft IPv4-Embedded Pv6 MT/MI-OSPFv3 February 2010 1. Introduction Within the double context of public IPv4 address exhaustion and 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]) based schemes are proposed to allow IPv6-IPv4 interconnection. These solutions require the injection of routes to IPv4-Embedded IPv6 prefixes [I-D.ietf-behave-address-format] in intra-domain routing protocols . In order to prevent any overload of the native IPv6 routing table with IPv4-Embedded IPv6 routes, this document defines new MT IDs (resp., MI IDs) which are required for the activation of multiple topologies (resp., Instances), where the native IPv6 topology (resp., Instance) would be distinct from the IPv4-Embedded IPv6 topology (resp., Instance). Operational reasons also motivate this approach which is meant to ease the migration to full IPv6. As a result, the unicast IPv4- Embedded IPv6 topology (resp., Instance) is used for unicast IPv4- Embedded IPv6 route computation purposes, and the multicast IPv4- Embedded IPv6 topology (resp., Instance) is used for multicast IPv4- Embedded IPv6 route computation purposes. This document does not make any preference between the solution described in [I-D.ietf-ospf-mt-ospfv3] and [I-D.ietf-ospf-af-alt]. Network administrators have to make their decisions based on local policies. If the multi-instance mechanism is deployed in an OSPFv3 network as a preference for multiple topologies, the MI extensions defined in this document may be used to support unicast/multicast IPv4-Embedded IPv6 routing. If MT-OSPFv3 mechanism is deployed in an OSPFv3 network as a preference for multiple topologies, the MT extensions defined in this document may be used to support unicast/ multicast IPv4-Embedded IPv6 routing. 2. IPv4-Embedded IPv6 OSPFv3 Topologies MT-OSPFv3 [I-D.ietf-ospf-mt-ospfv3] is a mechanism that has been specified to run various topologies based on several criteria such as the need to distinguish the IPv6 unicast topology from the IPv4 routing topology. Distinct MT IDs (Multi-Topology Identifiers) are assigned by IANA (e.g., MT ID# 0 for IPv6 routing topology, MT ID# 3 for IPv6 multicast topology, etc.). MT ID #5-#31 range is reserved for IETF consensus. This document requests the assignment of two new MT IDs for the following usages: Boucadair, et al. Expires August 16, 2010 [Page 4] Internet-Draft IPv4-Embedded Pv6 MT/MI-OSPFv3 February 2010 o IPv4-Embedded IPv6 unicast topology; o IPv4-Embedded IPv6 multicast topology. 3. IPv4-Embedded IPv6 OSPFv3 Instances [I-D.ietf-ospf-af-alt] specifies a mechanism to map each address family (AF) to a separate OSPFv3 [RFC5340] Instance identified by an ID. Many Instance IDs have been reserved for different AF (e.g., Instance ID#0 - #31 for IPv6 unicast AF, Instance ID#32 - #63 for IPv6 multicast AF, etc.). Instance ID#0 is used by default for IPv6 unicast AF. This document requests the assignment of two new Instance IDs for the IPv4-Embedded IPv6 AF: o IPv4-Embedded IPv6 unicast AF; o IPv4-Embedded IPv6 multicast AF. 4. Provisioning Adequate provisioning must be done according to [I-D.ietf-ospf-mt-ospfv3] and [I-D.ietf-ospf-af-alt], respectively, based on the corresponding mechanism that is actually used in an OSPFv3 network, in order to have a fully-connected IPv4-Embedded IPv6 unicast or multicast topology. 5. Procedure This document does not require any modification to the procedure specified in [I-D.ietf-ospf-mt-ospfv3] nor in [I-D.ietf-ospf-af-alt]. Nevertheless, routes to IPv4-Embedded IPv6 addresses or prefixes MUST be instantiated within an IPv4-Embedded IPv6 MT-OSPFv3 (resp., MI- OSPFv3). 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- Embedded IPv6 addresses. 6. Advertising IPv4-Embedded IPv6 Routes With one of the mechanisms (i.e., a separate OSPFv3 instance or a separate OSPFv3 topology) as described above, reachability of IPv4- Embedded IPv6 destinations can be advertised in an IPv6 network using OSPFv3. Boucadair, et al. Expires August 16, 2010 [Page 5] Internet-Draft IPv4-Embedded Pv6 MT/MI-OSPFv3 February 2010 In general, IPv4-Embedded IPv6 addresses and prefixes are advertised into an OSPFv3 network using AS External LSA [RFC5340], i.e.- with the advertising scope throughout the entire Autonomous System. This is because an advertising node in this case is most likely connected to one or more IPv4 networks, and as such, it functions as an Autonomous System Boundary Router (ASBR) in the perspective of OSPFv3 routing domain. Any OSPFv3 area that does not want to receive such advertisement can be configured as a stub area or with other routing policy. By default, the metric in an AS External LSA that carries one or more IPv4-Embedded IPv6 addresses and prefixes is a Type 1 external metric, which is then to be added to the metric of an intra-AS path during OSPFv3 routes calculation. By configuration on an ASBR, the metric can be set to a Type 2 external metric, which is considered much larger than any intra-AS path. The detail is referred to OSPFv3 specification [RFC5340]. In either case, an external metric may be exact the same unit as in an IPv4 network (running OSPFv2 or others), but may also be specified by a routing policy, the detail is outside of the scope of this document. Advertising IPv4-Embedded IPv6 addresses and prefixes using OSPFv3 inter-area prefix LSA is for future study. 7. Forwarding Only incoming datagrams destined to IPv4-Embedded IPv6 addresses are associated (and forwarded accordingly) with the IPv4-Embedded IPv6 unicast/multicast topology, respectively. WKP (i.e., 64:FF9B::/96) and/or LIR prefix defined in [I-D.ietf-behave-address-format] MUST be configured in all participating nodes. 8. IANA Considerations This document requests the following MT-OSPFv3 IDs: o MT ID# for IPv4-Embedded IPv6 unicast topology o MT ID# for IPv4-Embedded IPv6 multicast topology. and the following OSPFv3 Instance IDs: o Instance ID# for IPv4-Embedded IPv6 unicast AF; o Instance ID# for IPv4-Embedded IPv6 multicast AF. Boucadair, et al. Expires August 16, 2010 [Page 6] Internet-Draft IPv4-Embedded Pv6 MT/MI-OSPFv3 February 2010 9. Security Considerations This document does not introduce any security issue in addition to those defined in [RFC5340]. 10. Acknowledgements TBC 11. References 11.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF for IPv6", RFC 5340, July 2008. 11.2. Informative References [I-D.boucadair-behave-ipv6-portrange] Boucadair, M., Levis, P., Grimault, J., Villefranque, A., Kassi-Lahlou, M., Bajko, G., Lee, Y., Melia, T., and O. Vautrin, "Flexible IPv6 Migration Scenarios in the Context of IPv4 Address Shortage", draft-boucadair-behave-ipv6-portrange-04 (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-04 (work in progress), January 2010. [I-D.ietf-behave-v6v4-xlate] Li, X., Bao, C., and F. Baker, "IP/ICMP Translation Algorithm", draft-ietf-behave-v6v4-xlate-09 (work in progress), February 2010. Boucadair, et al. Expires August 16, 2010 [Page 7] Internet-Draft IPv4-Embedded Pv6 MT/MI-OSPFv3 February 2010 [I-D.ietf-behave-v6v4-xlate-stateful] Bagnulo, M., Matthews, P., and I. Beijnum, "Stateful NAT64: Network Address and Protocol Translation from IPv6 Clients to IPv4 Servers", draft-ietf-behave-v6v4-xlate-stateful-08 (work in progress), January 2010. [I-D.ietf-ospf-af-alt] Lindem, A., Mirtorabi, S., Roy, A., Barnes, M., and R. Aggarwal, "Support of address families in OSPFv3", draft-ietf-ospf-af-alt-10 (work in progress), December 2009. [I-D.ietf-ospf-mt-ospfv3] Mirtorabi, S. and A. Roy, "Multi-topology routing in OSPFv3 (MT-OSPFv3)", draft-ietf-ospf-mt-ospfv3-03 (work in progress), July 2007. Authors' Addresses Mohamed Boucadair France Telecom 3, Av Francois Chateau Rennes, 35000 France Email: mohamed.boucadair@orange-ftgroup.com 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 Boucadair, et al. Expires August 16, 2010 [Page 8] Internet-Draft IPv4-Embedded Pv6 MT/MI-OSPFv3 February 2010 Yiu L. Lee Comcast USA Email: Yiu_Lee@Cable.Comcast.com Boucadair, et al. Expires August 16, 2010 [Page 9]