Network Working Group C. Donley Internet-Draft CableLabs Intended status: Informational J. Brzozowski Expires: September 30, 2012 Comcast H. Liu D-Link V. Kuarsingh Rogers Communications J. Weil Time Warner Cable March 29, 2012 Design Considerations for an IPv6 CE Router draft-donley-v6ops-ce-router-design-00 Abstract This document describes design considerations for IPv6 CE routers. 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 September 30, 2012. Copyright Notice Copyright (c) 2012 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 Donley, et al. Expires September 30, 2012 [Page 1] Internet-Draft ipv6-ce-router-considerations March 2012 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. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Design Considerations . . . . . . . . . . . . . . . . . . . . . 3 2.1. Address acquisition . . . . . . . . . . . . . . . . . . . . 3 2.2. Transition technologies . . . . . . . . . . . . . . . . . . 4 3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4 4. Security Considerations . . . . . . . . . . . . . . . . . . . . 4 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 4 6. Informative References . . . . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 5 Donley, et al. Expires September 30, 2012 [Page 2] Internet-Draft ipv6-ce-router-considerations March 2012 1. Introduction This document descrbes design considerations for IPv6 customer edge (CE) routers designed for residential/small business use [I-D.ietf-v6ops-6204bis]. These routers may also support IPv4 and potentially one/more transition technologies. These design considerations are crafted to ensure a safe and orderly transition to IPv6 while maintaining a quality IP connection to the customer premise. 2. Design Considerations There are two overriding goals for CE routers: o Offer customers the best possible quality of experience. o Do not unnecessarily overwhelm ISP resources. 2.1. Address acquisition The IPv6 CE router needs to support connectivity to one or more access network architectures. There are generally three IPv6 address acquisition mechanisms in widespread use today: o stateful DHCPv6 [RFC3315] o Stateless Address Autoconfiguraton (SLAAC)[RFC4862] o unnumbered Design considerations for address acquisition: 1. IPv6 CE routers should support one or more of the above address acquisition mechanisms. 2. Only one address acquisition mechanism should be used for a given protocol (e.g. native IPv4/IPv6) at a given time. 3. Not all access architectures support all address acquisition mechanisms. When attached to access networks that do not support certain address acquisition mechanisms, the CE router should not attempt to use unsupported addressing mechanisms, if it is possible to identify such a limitation. 4. The CE router should attempt address acquisition gracefully. It should not overwhelm service provider provisioning servers. Donley, et al. Expires September 30, 2012 [Page 3] Internet-Draft ipv6-ce-router-considerations March 2012 5. If a Service Provider sends a hint to the CE router as to which addressing mechanism to use, the CE router should honor the hint. 2.2. Transition technologies CE routers should support technologies for providing ipv4 access over IPv6 networks and IPv6 access over IPv4 networks. While the IETF has defined a large number of such protocols, the CE router need not implement all of them. In particular, it should implement those technologies required by ISPs. At the time of this writing, such technologies include: o Native Dual-Stack o IPv6 Rapid Deployment (6RD) [RFC5969] o Dual-Stack Lite (DS-Lite)[RFC6333] Design considerations for transition technologies: 1. Native IPv4/IPv6 service should be preferred over tunneled service. 2. Avoid NAT, when possible. [I-D.donley-nat444-impacts] 3. While multihoming (supporting both native/tunneled service for a given protocol) may be a valid approach, it need not be supported. Singlehoming should also be considered a valid approach. 3. IANA Considerations This document makes no request of IANA. Note to RFC Editor: this section may be removed on publication as an RFC. 4. Security Considerations TBD 5. Acknowledgements Donley, et al. Expires September 30, 2012 [Page 4] Internet-Draft ipv6-ce-router-considerations March 2012 6. Informative References [I-D.donley-nat444-impacts] Donley, C., Howard, L., Colorado, U., and V. Kuarsingh, "Assessing the Impact of Carrier-Grade NAT on Network Applications", draft-donley-nat444-impacts-03 (work in progress), November 2011. [I-D.ietf-v6ops-6204bis] Singh, H., Beebee, W., Donley, C., Stark, B., and O. Troan, "Basic Requirements for IPv6 Customer Edge Routers", draft-ietf-v6ops-6204bis-07 (work in progress), March 2012. [RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C., and M. Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3315, July 2003. [RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless Address Autoconfiguration", RFC 4862, September 2007. [RFC5969] Townsley, W. and O. Troan, "IPv6 Rapid Deployment on IPv4 Infrastructures (6rd) -- Protocol Specification", RFC 5969, August 2010. [RFC6333] Durand, A., Droms, R., Woodyatt, J., and Y. Lee, "Dual- Stack Lite Broadband Deployments Following IPv4 Exhaustion", RFC 6333, August 2011. Authors' Addresses Chris Donley CableLabs Email: c.donley@cablelabs.com John Brzozowski Comcast Hans Liu D-Link Donley, et al. Expires September 30, 2012 [Page 5] Internet-Draft ipv6-ce-router-considerations March 2012 Victor Kuarsingh Rogers Communications Jason Weil Time Warner Cable Donley, et al. Expires September 30, 2012 [Page 6]