Internet Engineering Task Force M. Townsley Internet-Draft O. Troan Intended status: Informational cisco Expires: June 14, 2012 December 12, 2011 Basic Requirements for IPv6 Customer Edge Routers - multihoming and transition draft-townsley-troan-ipv6-ce-transitioning-01 Abstract This document specifies general IPv6 multihoming and specific 6rd transitioning requirements for an IPv6 Customer Edge (CE) router. 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/. 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." This Internet-Draft will expire on June 14, 2012. Copyright Notice Copyright (c) 2011 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 Simplified BSD License. Townsley & Troan Expires June 14, 2012 [Page 1]
Internet-Draft IPv6 CE router requirements December 2011 1. Introduction This document defines transitioning and multihoming IPv6 features for a residential or small office router referred to as an IPv6 CE router. Typically these routers also support IPv4. 1.1. 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]. 2. Terminology SRIB A Source Address Routing Information Base containing an entry per delegated prefix. Each entry points to one or more Destination Address Routing Tables (DRIB). DRIB A Destination Address Routing Information Base used for destination address longest matching lookups. Each entry points to one or more next-hops. 3. IPv6 Multi-Prefix Multihoming A multihomed, multiprefix, IPv6 CE router has multiple WAN interfaces connecting it to one or more Service Providers. The interfaces may be "real" or "virtual" in the case of tunneling technology such as 6rd. The CE router receives one or more delegated prefixes, each associated with one or more WAN interfaces. The CE router has a single SRIB, and one DRIB associated with each WAN Interface. WAN interfaces are used to send Ingress traffic from the Internet to the End-User, and Egress traffic from the End-User network to the Internet. Ingress traffic may be received on any active interface at any time. Egress traffic follows a set of rules within the CE in order to choose the proper WAN interface. This is important not only in order to choose the best path, but also because the networks that the CE are connected to typically employ source address verification mechanisms. Packets arriving at the CE have an IPv6 source address chosen by the host [RFC3484]. The SRIB contains an entry for each delegated prefix with a pointer to one or more DRIBs. A longest matching lookup based upon the source address of each arriving packet is performed within Townsley & Troan Expires June 14, 2012 [Page 2]
Internet-Draft IPv6 CE router requirements December 2011 the SRIB to determine the DRIB(s). The egress WAN interface to use for sending a packet is then chosen by performing a longest matching lookup within the resulting DRIB(s). Multihoming requirements: MH-1: An IPv6 CE router MUST create a separate DRIB for each WAN interface (real or virtual) and installs a route for the associated delegated prefix, default route and more specific routes. MH-2: An IPv6 CE router MUST create an SRIB containing entries for associated delegated prefixes. Each entry points to one or more DRIBs. An entry points to multiple DRIBs only in the case where an identical delegated prefix is associated with multiple WAN interfaces. MH-3: When forwarding a packet from a LAN interface, the CE router MUST do a longest matching lookup based on the packet's Source Address in the SRIB. A Destination Address lookup is then performed in the corresponding DRIB or DRIBs. When there are multiple equal matches, the route with the lowest cost is chosen. 4. 6rd Sunsetting Requirements 6RDS-1: Multihoming as defined in section Section 3 MUST be supported, allowing 6rd and native packets to be sent and received as long as 6rd configuration is provided by the ISP. 6RDS-2: By default, the 6rd virtual interface MUST be assigned a higher routing cost than a native IPv6 interface. 6RDS-3: The IPv6 CE router MUST support that 6rd and native IPv6 delegated prefixes are identical or different, and operate as defined in the multihoming section. 5. Security Considerations 6. Acknowledgements Townsley & Troan Expires June 14, 2012 [Page 3]
Internet-Draft IPv6 CE router requirements December 2011 7. IANA Considerations This memo includes no request to IANA. 8. References 8.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2131] Droms, R., "Dynamic Host Configuration Protocol", RFC 2131, March 1997. [RFC5969] Townsley, W. and O. Troan, "IPv6 Rapid Deployment on IPv4 Infrastructures (6rd) -- Protocol Specification", RFC 5969, August 2010. 8.2. Informative References [RFC3484] Draves, R., "Default Address Selection for Internet Protocol version 6 (IPv6)", RFC 3484, February 2003. [RFC6204] Singh, H., Beebee, W., Donley, C., Stark, B., and O. Troan, "Basic Requirements for IPv6 Customer Edge Routers", RFC 6204, April 2011. Authors' Addresses Mark Townsley cisco Email: Ole Troan cisco Email: Townsley & Troan Expires June 14, 2012 [Page 4]