Internet Engineering Task Force T. Winters Internet-Draft QA Cafe Updates: 7084 (if approved) 17 November 2022 Intended status: Informational Expires: 21 May 2023 IPv6 CE Routers LAN Prefix Delegation draft-winters-v6ops-cpe-lan-pd-00 Abstract This document defines requirements for IPv6 CE Routers to support DHCPv6 Prefix Delegation for redistributing any unused prefix(es) that were delegated to the IPv6 CE Router. This document updates RFC 7084. 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 https://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 21 May 2023. Copyright Notice Copyright (c) 2022 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 (https://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 Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Winters Expires 21 May 2023 [Page 1] Internet-Draft IPv6 CE Routers LAN Prefix Delegation November 2022 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 2 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2 4. Architecture . . . . . . . . . . . . . . . . . . . . . . . . 3 5. Requirements . . . . . . . . . . . . . . . . . . . . . . . . 3 6. Security Considerations . . . . . . . . . . . . . . . . . . . 4 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 8. Acknowledements . . . . . . . . . . . . . . . . . . . . . . . 4 9. Normative References . . . . . . . . . . . . . . . . . . . . 4 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction This document defines DHCPv6 Prefix Delegation in IPv6 CE Routers ([RFC7084]) in order to properly utilize the IPv6 prefixes assigned by service providers. Many ISP will assign a prefix larger then /64 to the CE Router as recommended in [RFC6177]. If a IPv6 CE Router doesn't support IA_PD on the LAN it will not be able to assign any prefixes beyond itself limiting the usefulness of assigning prefixes larger then /64. Supporting IA_PD on the LAN interfaces will allow for those prefixes to be distributed into a network to be useable. 2. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. This document also makes use of internal conceptual variables to describe protocol behavior and external variables that an implementation must allow system administrators to change. The specific variable names, how their values change, and how their settings influence protocol behavior are provided to demonstrate protocol behavior. An implementation is not required to have them in the exact form described here, as long as its external behavior is consistent with that described in this document. 3. Terminology The following terminology is defined for this document. * IPv6 CE Router: A router intended for home or small-office use that forwards packets explicitly addressed to itself as defined in [RFC7084]. Winters Expires 21 May 2023 [Page 2] Internet-Draft IPv6 CE Routers LAN Prefix Delegation November 2022 * Internet Service Provider (ISP): An entity that provides access to the Internet. In this document, a service provider specifically offers Internet access using IPv6, and may also offer IPv4 Internet access. The service provider can provide such access over a variety of different transport methods such as DSL, cable, wireless, and others. 4. Architecture +-----------+ | Service | | Provider | | Router | +-----+-----+ | | | Customer | Internet Connection | +-----v-----+ | IPv6 | | CE | | Router | +-----+-----+ | +----+-+-------+ | | | | +---+----+ +-----+------+ | IPv6 | | | | Host | | Router | | | | | +--------+ +------------+ 5. Requirements The IPv6 CE Router distributes configuration information obtained during WAN interface provisioning to IPv6 hosts and routers. A router based on [RFC7084] previously would only address IPv6 hosts, this update to allow for addressing and routing of routers. LAN Prefix Delegation (PD) Requirements LPD-1: The IPv6 CE Router MUST support DHCPv6 server capable of IPv6 prefix assignment according to [RFC8415] (Idenity Association for Prefix Delegation (IA_PD) option). Winters Expires 21 May 2023 [Page 3] Internet-Draft IPv6 CE Routers LAN Prefix Delegation November 2022 LPD-2: The IPv6 CE Router MUST assign addresses from the delegated prefix to the number of interfaces. If not enough addresses are available the IPv6 CE Router SHOULD log a system management error. LPD-3: After interface address assignment the IPv6 CE Router MUST make the remaining IPv6 prefixes available to other Routers via Prefix Delegation LPD-4: The IPv6 CE Router MUST give out a IA_PD of the remaining prefixes with a IA_PD size of 64. LPD-5: The IPv6 CE Router MUST install a route to the IA_PD assigned with a next-hop of the IPv6 node assigned the address. LPD-6: If a IPv6 CE Router recieves IPv6 prefixes of size 64 it MUST enable delegating relay according to [RFC8987]. The MUST forward all the DHCPv6 Relay messages to the All_DHCP_Relay_Agents_and_Servers multicast address. 6. Security Considerations This document does not add any new security considerations beyond those mentioned in Section 4 of [RFC8213] and Section 22 of [RFC8415]. 7. IANA Considerations This document makes no request of IANA. 8. Acknowledements Thanks to the following people (in alphabetical order) for their guidance and feedback: Marion Dillon, Esko Dijk, Ted Lemon, Michael Richardson. 9. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC6177] Narten, T., Huston, G., Roberts, L., and RFC Publisher, "IPv6 Address Assignment to End Sites", BCP 157, RFC 6177, DOI 10.17487/RFC6177, March 2011, . Winters Expires 21 May 2023 [Page 4] Internet-Draft IPv6 CE Routers LAN Prefix Delegation November 2022 [RFC7084] Singh, H., Beebee, W., Donley, C., Stark, B., and RFC Publisher, "Basic Requirements for IPv6 Customer Edge Routers", RFC 7084, DOI 10.17487/RFC7084, November 2013, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8213] Volz, B., Pal, Y., and RFC Publisher, "Security of Messages Exchanged between Servers and Relay Agents", RFC 8213, DOI 10.17487/RFC8213, August 2017, . [RFC8415] Mrugalski, T., Siodelski, M., Volz, B., Yourtchenko, A., Richardson, M., Jiang, S., Lemon, T., Winters, T., and RFC Publisher, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 8415, DOI 10.17487/RFC8415, November 2018, . [RFC8987] Farrer, I., Kottapalli, N., Hunek, M., Patterson, R., and RFC Publisher, "DHCPv6 Prefix Delegating Relay Requirements", RFC 8987, DOI 10.17487/RFC8987, February 2021, . Author's Address Timothy Winters QA Cafe 100 Main Street, Suite #212 Dover, NH 03820 United States of America Email: tim@qacafe.com Winters Expires 21 May 2023 [Page 5]