Network Working Group S. Miyakawa Internet-Draft NTT Communications Corporation Expires:
Aug 25,December 28, 2003 R. Droms Cisco Systems FebJune 29, 2003 Requirements for IPv6 prefix delegation draft-ietf-ipv6-prefix-delegation-requirement-01.txtdraft-ietf-ipv6-prefix-delegation-requirement-02.txt Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. 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 Aug 25,December 28, 2003. Copyright Notice Copyright (C) The Internet Society (2003). All Rights Reserved. Abstract This document describes requirements for how IPv6 address prefixes should be delegated to an IPv6 subscriber's network (or "site"). 1. Introduction With the deployment of IPv6 ,, several Internet Service Providers are ready to offer IPv6 access to the public. In conjunction with widely deployed "always on" media such as ADSL,ADSL and the expectation that customerscusomters will be assigned a /48 IPv6 unicast address prefix,prefix (see RFC3513  and section 3 of RFC3177 ), an efficient mechanism for delegating address prefixes to the customers sites is needed. The delegation mechanism will be intended to automate the process of informing the customer's networking equipment of the prefixes to be used at the customer's site. This document clarifies the requirements for IPv6 address prefix delegation from the ISP to the site. 2. Requirements 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 RFC2119 . 3.Scenario and terminology The following figure illustrates a likely example for the organization of a network providing subscription IPv6 service: /------\ / \ + | / \ / +---------------+ +--------+/ \------/ |ISP Edge Router|Point-to-point|Customer+ | +--------------+ Router | Customer networks | (PE) | link | (CPE) + +---------------+ +--------+\ /------\ \ / \ + | \ / \------/ Figure 1: Illustration of ISP-customer network architecture Terminology: PEPE: Provider edge device; the device connected to the service provider's network infrastructure at which the link to the customer site is terminated CPECPE: Customer providedpremises equipment; the device at the customer site at which the link to the ISP is terminated 4.3. Requirements for Prefix Delegation The purpose of the prefix delegation mechanism is to communicatedelegate and manage prefixes to the CPE automatically. 4.13.1 Number and Length of Delegated PrefixedPrefixes The prefix delegation mechanism SHOULDshould allow for delegation of prefixes of length /48, /64 and other lengths,lengths between /48 and SHOULD/64, inclusively. Other lengths may be supported. The mechanism should allow for delegation of more than one prefix to the customer. 4.23.2 Use of Delegated Prefixes in Customer Network The prefix delegation mechanism MUST NOTmust not prohibit or inhibit the assignment of longer prefixes, created from the delegated prefixes, to links within the customer network. It is not a requirement that the prefix delegation mechanism provide for the reporting of prefix delegation within the customer network back to the ISP. 4.3 Automated3.3 Static and Dynamic Assignment The prefix delegation mechanism SHOULDshould allow for long-lived pre- assignmentstatic pre-assignment of one or more prefix(es) to a customerprefixes and for automated, possibly short-lived on-demand dynamic assignment of a prefixprefixes to a customer on demand. 4.4customer. 3.4 Policy-based Assignment The prefix delegation mechanism SHOULDshould allow for the use of policy in assigning prefixes to a customer. For example, the customer's identity and type of subscribed service may be used to determine the address block from which the customer's prefix is selected, and the length of the prefix assigned to the customer. 4.53.5 Security and Authentication The prefix delegation mechanism MUSTmust provide for reliable authentication of the identity of the customer to which the prefixes are to be assigned, and MUSTmust provide for reliable, secure transmission of the delegated prefixes to the customer. 4.63.6 Accounting The prefix delegation mechanism MUSTmust allow for the ISP to provide accounting information about delegated prefixes. 4.7 Layer 23.7 Hardware technology Considerations The method SHOULDprefix delegation mechanism should work on any layer 2 technologies. In other words, ithardware technology and should be layer 2hardware technology independent. Though, at the same time, it should be noted that now ISP would like to have a solution for Point-to-Point link which has own authenticationThe mechanism must work on shared links. The mechanism first. PPP link with CHAP authentication is a good example. (Simulated) Ethernet and IEEE802.11 (wireless LAN) should be covered in near future, but they have low priority (just) for now. It should be clarified that the methodshould work with all L2 protocolshardware technologies either with authentication mechanism or without, but ISPISPs would like to take advantage of a L2 protocol'shardware technology's authentication mechanism if it exits. 5.4. IANA Considerations There are no IANA considerations in this document. 6.5. Security considerations Section 4.53.5 specifies security requirements for the prefix delegation mechanism. References  Bradner, S., "Key words for useFor point to point links, where one trusts that there is no man in RFCsthe middle, or one trusts layer two authentication, authentication may not be necessary. A rogue delegating router can issue bogus prefixes to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. a requesting router. This may cause denial of service due to unreachability. An intruder requesting router may be able to mount a denial of service attack by repeated requests for delegated prefixes that exhaust the delegating router's available prefixes. Informative References  Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", RFC 2460, December 1998. Author's Address Hinden, R. and S. Deering, "Internet Protocol Version 6 (IPv6) Addressing Architecture", RFC 2460, December 1998.  IESG, IAB,., "IAB/IESG Recommendations on IPv6 Address", RFC 3177, September 2001. Authors' Addresses Shin Miyakawa Innovative IP Architecture Center, NTT Communications Corporation Tokyo Opera City Tower 21F, 3-20-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo,Japan Phone: +81-3-6800-3262 EMail: email@example.com Ralph Droms Cisco Systems 300 Apollo Drive Chelmsford,1414 Massachusetts Avenue Boxborough, MA 0188601719 USA Phone: +1-978-497-4733+1 978.936.1674 EMail: firstname.lastname@example.org Full Copyright Statement Copyright (C) The Internet Society (2003). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. 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