INTERNET-DRAFT Donald Eastlake 3rd
UPDATES BCP 37 / RFC 2780 Motorola
Scott Bradner
Harvard University
Expires: October 2001 April 2001
Extended IP Versions
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Status of This Document
Distribution of this draft, which is intended to become part of Best
Current Practice 37, is unlimited. Comments should be sent to the
authors.
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC 2026. Internet-Drafts are
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Copyright Notice
Copyright (C) The Internet Society (2001). All Rights Reserved.
Abstract
The current four bit Internet Protocol (IP) Version field provides
for such a limited number of versions that very tight control must be
exercised on their allocation as documented in [RFC 2780].
Provisions are specified whereby one value of that field is extended
to provide more easily allocated values.
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Table of Contents
Status of This Document....................................1
Copyright Notice...........................................1
Abstract...................................................1
Table of Contents..........................................2
1. Introduction............................................3
2. Extended IP Versions....................................3
3. IANA Considerations.....................................4
4. Security Considerations.................................4
References.................................................5
Authors Addresses..........................................5
Full Copyright Statement...................................6
Expiration and File Name...................................6
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1. Introduction
Since the begining of the Internet Protocol (IP), it has had a four
bit version field. This was entirely adequate in the early days when
the Internet engineering community was tiny and went fairly rapdily
through version 1, 2, and 3, before stabilizing on version 4 (IPv4)
under which the Internet has prospered [RFC 791].
A few years ago, when a need was felt for specification of a new
version, the remaining version number space was barely adequate to
assign versions to the main contenders, leading to the selection of
IPv6 as the main path [RFC 2460]. Furthermore, the Internet
engineering community has grown by over two orders of magnitude since
the specification of IP, with IETF attendence going from 15 to 3000
potentially increasing demand for experimental parameter values.
To continue the successful tradition of simple free availability of
parameter values, IP version numbers should be extended. How
beneficial this will be in this particular case is unclear. But if
the prospering of Internet Technology has taught us anything, it is
that simple free availability of parameter values can lead to
surprising creativity and vigor. Perhaps this mechanism will do that
or perhaps it will turn out to be little, like the DNS Class
mechanism. But the cost is small and the potential benefit hard to
bound.
An equivalent 4 bit IP version number can be allocated for any
extended IP version, when warranted, under the IP version allocation
procedure specified in [RFC 2780].
2. Extended IP Versions
The Internet Protocol packet format is defined to begin with a four
bit Version as follows:
0
0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Version| ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
To extend this versioning mechanism, this document specifies that the
version number (TBD (suggest 1)) is followed by a twelve bit
extention as shown below.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| (TBD) | x | y | ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The version number is considered an unsigned integer equal to x*256 +
y. This produces version numbers in the range 0 to 4095 but the
first sixteen values, 0 through 15, are reserved for future
definition and to avoid conflict with non-extended version numbers.
This structure causes the remainder of the IP packet to be 16 bit
aligned.
3. IANA Considerations
IP Version number nibble value (TBD (suggest 1)) is allocated for
extended IP Versions as documnted herein.
Extended IP versions 0 through 15 are reserved and required a
"Standards Action" as defined in RFC 2434 for allocation.
Extended IP version 16 through 4095 are to be allocated in sequential
order based on "Specification Required" as defined in RFC 2434.
4. Security Considerations
Firwalls or other software which wishes to pass only packets they
understand should block all packets with extended IP versions.
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References
[RFC 791] - "Internet Protocol", J. Postel, September 1981.
[RFC 2434] - "Guidelines for Writing an IANA Considerations Section
in RFCs", T. Narten, H. Alvestrand, October 1998.
[RFC 2460] - "Internet Protocol, Version 6 (IPv6) Specification",
Deering, S. and R. Hinden, December 1998.
[RFC 2780] - "IANA Allocation Guidelines For Values In the Internet
Protocol and Related Headers", S. Bradner, V. Paxon, March 2000.
Authors Addresses
Scott Bradner
Harvard University
Cambridge, MA 02138 USA
Telephone: +1 617 495 3864
EMail: sob@harvard.edu
Donald E. Eastlake 3rd
Motorola
155 Beaver Street
Milford, MA 01757 USA
Telephone: +1-508-634-2066 (h)
+1-508-261-5434 (w)
FAX: +1-508-261-4447 (w)
EMail: Donald.Eastlake@motorola.com
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Full Copyright Statement
Copyright (C) The Internet Society (2001). 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. However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be
followed, or as required to translate it into languages other than
English.
The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Expiration and File Name
This draft expires October 2001.
Its file name is draft-eastlake-ext-ip-ver-02.txt.
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