INTERNET-DRAFT R. Hinden, Nokia
February 4, 2003 S. Deering, Cisco
IPv6 Global Unicast Address Format for the 2000::/3 Prefix
<draft-ietf-ipv6-unicast-aggr-v2-01.txt>
Status of this Memo
This document is an Internet-Draft and is subject to 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/1id-abstracts.html
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html
This internet draft expires on August 4, 2003.
Abstract
This document defines the unicast address format for the 2000::/3
(001 binary) prefix. The address format defined in this document is
consistent with RFC2460 "Internet Protocol, Version 6 (IPv6)
Specification" and RFCXXXX "IP Version 6 Addressing Architecture".
This documented replaces RFC2374 "An IPv6 Aggregatable Global Unicast
Address Format". RFC2374 will become historic.
draft-ietf-ipv6-unicast-aggr-v2-01.txt [Page 1]
INTERNET-DRAFT IPv6 Address Format for 2000::/3 Prefix February 2003
1.0 Introduction
This document defines the unicast address format for the 2000::/3
(001 binary) prefix. The address format defined in this document is
consistent with the IPv6 Protocol [IPV6] and the "IPv6 Addressing
Architecture" [ARCH]. It is designed to facilitate scalable Internet
routing.
RFC2374, "An IPv6 Aggregatable Global Unicast Address Format" defined
a structured allocation structure of global unicast IPv6 addresses
with named fields (e.g., TLA, NLA, etc.).
While this approach was originally thought to be a good way to
allocate IPv6 addresses, subsequent experience and discussion showed
that it would be better to leave flexibility in the definition of
IPv6 allocation policies to the Internet Address Registries, in order
to allow a better balance among the competing requirements. This is
consistent with the recommendations made by the IAB and IESG in
[RFC3177].
This document removes the defined structure and generalizes the
fields in the global unicast address format.
This documented replaces RFC2374, "An IPv6 Aggregatable Global
Unicast Address Format". RFC 2374 will become historic.
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 [RFC 2119].
2.0 Address Format
The general format for IPv6 global unicast addresses as defined in
"IP Version 6 Addressing Architecture" [ARCH] is as follows:
| n bits | m bits | 128-n-m bits |
+------------------------+-----------+----------------------------+
| global routing prefix | subnet ID | interface ID |
+------------------------+-----------+----------------------------+
where the global routing prefix is a (typically hierarchically-
structured) value assigned to a site (a cluster of subnets/links),
the subnet ID is an identifier of a subnet within the site, and the
interface ID is as defined in section 2.5.1 of [ARCH].
[ARCH] also requires that all unicast addresses, except those that
start with binary value 000, have Interface IDs that are 64 bits long
draft-ietf-ipv6-unicast-aggr-v2-01.txt [Page 2]
INTERNET-DRAFT IPv6 Address Format for 2000::/3 Prefix February 2003
and to be constructed in Modified EUI-64 format.
The specific format of global unicast address under the 2000::/3
prefix is:
| 3 | n bits | 61-n bits | 64 bits |
+---+--------------------+-----------+----------------------------+
|001| routing prefix | subnet ID | interface ID |
+---+--------------------+-----------+----------------------------+
where the routing prefix is a value assigned to a identify a site (a
cluster of subnets/links), the subnet ID is an identifier of a subnet
within the site, and the interface ID is in modified EUI-64 format as
defined in [ARCH].
3.0 Acknowledgments
The authors would like to express our thanks to Margaret Wasserman,
Brian Carpenter, Pekka Savola, Alain Durand, Fred Templin, Michel Py,
and Jun-ichiro itojun Hagino for their review and constructive
comments.
4.0 References
Normative
[ARCH] Hinden, R., "IP Version 6 Addressing Architecture",
Internet Draft, <draft-ietf-ipngwg-addr-arch-v3-11.txt>,
October 2002.
[IPV6] Deering, S., R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", RFC2460, December 1998.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", RFC2119, BCP14, March 1997.
[RFC3177] IAB/IESG, "Recommendations on IPv6 Address Allocations to
Sites" RFC3177, September 2001.
5.0 Security Considerations
IPv6 addressing documents do not have any direct impact on Internet
infrastructure security.
draft-ietf-ipv6-unicast-aggr-v2-01.txt [Page 3]
INTERNET-DRAFT IPv6 Address Format for 2000::/3 Prefix February 2003
6.0 Authors' Addresses
Robert M. Hinden
Nokia
313 Fairchild Drive
Mountain View, CA
US
email: hinden@iprg.nokia.com
Stephen E. Deering
Cisco Systems, Inc.
170 West Tasman Drive
San Jose, CA 95134-1706
US
email: deering@cisco.com
draft-ietf-ipv6-unicast-aggr-v2-01.txt [Page 4]
