Analysis of the 64-bit Boundary in IPv6 Addressing
draft-ietf-6man-why64-00
6MAN B. Carpenter, Ed.
Internet-Draft Univ. of Auckland
Intended status: Informational T. Chown
Expires: October 13, 2014 Univ. of Southampton
F. Gont
SI6 Networks / UTN-FRH
S. Jiang
Huawei Technologies Co., Ltd
A. Petrescu
CEA, LIST
A. Yourtchenko
cisco
April 11, 2014
Analysis of the 64-bit Boundary in IPv6 Addressing
draft-ietf-6man-why64-00
Abstract
The IPv6 unicast addressing format includes a separation between the
prefix used to route packets to a subnet and the interface identifier
used to specify a given interface connected to that subnet.
Currently the interface identifier is defined as 64 bits long for
almost every case, leaving 64 bits for the routing prefix. This
document describes the advantages of this fixed boundary and analyses
the issues that would be involved in treating it as a variable
boundary.
Status of This Memo
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on October 13, 2014.
Carpenter, et al. Expires October 13, 2014 [Page 1]
Internet-Draft Why 64 April 2014
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Advantages of a fixed identifier length . . . . . . . . . . . 4
3. Arguments for shorter identifier lengths . . . . . . . . . . 5
3.1. Insufficient address space delegated . . . . . . . . . . 5
3.2. Hierarchical addressing . . . . . . . . . . . . . . . . . 6
3.3. Audit requirement . . . . . . . . . . . . . . . . . . . . 6
3.4. Concerns over ND cache exhaustion . . . . . . . . . . . . 6
4. Effects of varying the interface identifier length . . . . . 7
4.1. Interaction with IPv6 specifications . . . . . . . . . . 7
4.2. Possible areas of breakage . . . . . . . . . . . . . . . 9
4.3. Experimental observations . . . . . . . . . . . . . . . . 11
4.3.1. Survey of the processing of Neighbor Discovery
options with prefixes other than /64 . . . . . . . . 11
4.3.2. Other Observations . . . . . . . . . . . . . . . . . 13
4.4. Implementation and deployment issues . . . . . . . . . . 13
4.5. Privacy issues . . . . . . . . . . . . . . . . . . . . . 14
5. Security Considerations . . . . . . . . . . . . . . . . . . . 15
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 16
8. Change log [RFC Editor: Please remove] . . . . . . . . . . . 16
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 17
9.1. Normative References . . . . . . . . . . . . . . . . . . 17
9.2. Informative References . . . . . . . . . . . . . . . . . 20
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22
1. Introduction
IPv6 addresses were originally chosen to be 128 bits long to provide
flexibility and new possibilities, rather than simply relieving the
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