Network Working Group S. Miyakawa
Internet-Draft NTT Communications Corporation
Expires: Aug 25, 2003 R. Droms
Cisco Systems
Feb 2003
Requirements for IPv6 prefix delegation
draft-ietf-ipv6-prefix-delegation-requirement-01.txt
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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 [2], several Internet Service Providers
are ready to offer IPv6 access to the public. In conjunction with
widely deployed "always on" media as ADSL, and the expectation that
customers will be assigned a /48 IPv6 address prefix, an efficient
mechanism for delegating address prefixes to the customers sites is
needed. The delegation mechanism will be intended to automate the
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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 [1].
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) +
+---------------+ +--------+\ /------\
\ / \
+ |
\ /
\------/
Illustration of ISP-customer network architecture
Terminology:
PE Provider edge device; the device at which the link to the customer
site is terminated
CPE Customer provided equipment; the device at the customer site at
which the link to the ISP is terminated
4. Requirements for Prefix Delegation
The purpose of the prefix delegation mechanism is to communicate
prefixes to the CPE automatically.
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4.1 Number and Length of Delegated Prefixed
The prefix delegation mechanism SHOULD allow for delegation of
prefixes of length /48, /64 and other lengths, and SHOULD allow for
delegation of more than one prefix to the customer.
4.2 Use of Delegated Prefixes in Customer Network
The prefix delegation mechanism MUST 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 Automated Assignment
The prefix delegation mechanism SHOULD allow for long-lived pre-
assignment of one or more prefix(es) to a customer and for
automated, possibly short-lived assignment of a prefix to a customer
on demand.
4.4 Policy-based Assignment
The prefix delegation mechanism SHOULD 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.
4.5 Security and Authentication
The prefix delegation mechanism MUST provide for reliable
authentication of the identity of the customer to which the prefixes
are to be assigned, and MUST provide for reliable, secure
transmission of the delegated prefixes to the customer.
4.6 Accounting
The prefix delegation mechanism MUST allow for the ISP to provide
accounting information about delegated prefixes.
4.7 Layer 2 Considerations
The method SHOULD work on any layer 2 technologies. In other words,
it should be layer 2 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 authentication mechanism first.
PPP link with CHAP authentication is a good example. (Simulated)
Ethernet and IEEE802.11 (wireless LAN) should be covered in near
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future, but they have low priority (just) for now. It should be
clarified that the method should work with all L2 protocols either
with authentication mechanism or without, but ISP would like to take
advantage of a L2 protocol's authentication mechanism if it exits.
5. IANA Considerations
There are no IANA considerations in this document.
6. Security considerations
Section 4.5 specifies security requirements for the prefix delegation
mechanism.
References
[1] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997.
[2] Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6)
Specification", RFC 2460, December 1998.
Author's Address
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: miyakawa@nttv6.jp
Ralph Droms
Cisco Systems
300 Apollo Drive
Chelmsford, MA 01886
Phone: +1-978-497-4733
EMail: rdroms@cisco.com
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