Network Working Group S. Miyakawa Request for Comments: 3769 NTT Communications Corporation Category: Informational R. Droms Cisco June 2004 Requirements for IPv6 Prefix Delegation Status of this Memo This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (2004).
AbstractThis document describes requirements for how IPv6 address prefixes should be delegated to an IPv6 subscriber's network (or "site"). 1], several Internet Service Providers are ready to offer IPv6 access to the public. In conjunction with widely deployed "always on" media such as ADSL and the expectation that customers will be assigned a /48 IPv6 unicast address prefix (see RFC 3513  and section 3 of RFC 3177 ), an efficient mechanism for delegating address prefixes to the customer's 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.
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: PE: Provider edge device; the device connected to the service provider's network infrastructure at which the link to the customer site is terminated CPE: Customer premises equipment; the device at the customer site at which the link to the ISP is terminated
The mechanism should work with all hardware technologies with either an authentication mechanism or without, but ISPs would like to take advantage of the hardware technology's authentication mechanism if it exists. Section 3.6 specifies security requirements for the prefix delegation mechanism. For point to point links, where one trusts that there is no man in the middle, or one trusts layer two authentication, authentication may not be necessary. A rogue PE can issue bogus prefixes to a requesting router. This may cause denial of service due to unreachability. A rogue CPE may be able to mount a denial of service attack by repeated requests for delegated prefixes that exhaust the PE's available prefixes.  Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", RFC 2460, December 1998.  IAB and IESG, "IAB/IESG Recommendations on IPv6 Address", RFC 3177, September 2001.  Hinden, R. and S. Deering, "Internet Protocol Version 6 (IPv6) Addressing Architecture", RFC 3513, April 2003.
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