[Search] [txt|pdf|bibtex] [Tracker] [WG] [Email] [Nits]

Versions: 00 01 02 03 04 05                                             
Network Working Group                                      G. Michaelson
Request for Comments: DRAFT                                        APNIC
Expires December 2006


             Canonical representation of 4-byte AS numbers

draft-michaelson-4byte-as-representation-00.txt


Status of this Memo


   By submitting this Internet-Draft, each author represents that any
   applicable patent or other IPR claims of which he or she is aware
   have been or will be disclosed, and any of which he or she becomes
   aware will be disclosed, in accordance with Section 6 of BCP 79.

   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/ietf/1id-abstracts.txt

      The list of Internet-Draft Shadow Directories can be accessed at
      http://www.ietf.org/shadow.html.

                                Abstract

    A single representation for 4-byte AS numbers is proposed, to avoid any
    confusion in interpreting the two 2-byte quantities that make them. The
    syntax chosen avoids collision with BGP community string parsing of AS
    numbers.

    It is recommended that only this representation be used by all documents
    and systems referring to 4-byte AS numbers.
    Nomenclature


1.0 Proposed canonical 4-byte AS representation

4 Byte AS numbers are defined in [1].

It is proposed to identify 4-byte AS Numbers using a syntax of
<high order 16 bit value in decimal>.<low order 16 bit value in decimal>.

Accordingly, a 4-byte AS Number of value 65546 (decimal) would be
identified as "1.10".

2.0 Terminology

    "2-byte only AS Numbers" refers to AS Numbers in the range 0 - 65535

    "4-byte only AS Numbers" refers to AS Numbers in the range 1.0 -
    65535.65535 (decimal range 65,536 - 4,294,967,295)

    "4-byte AS Numbers" refers to AS Numbers in the range 0.0 - 65535.65535
    (decimal range 0 - 4,294,967,295)

3.0 Discussion

   To avoid confusion, a single notation to represent 4-byte AS is
   required.  Initially, the ":" was proposed to separate the 2-byte
   components. However this clashes with use of the ":" character in
   community attribute syntax.

   This notation has been informally adopted by at least one vendor, and
   used consistently in presentations in the RIR community towards the
   deployment of 4-byte AS. Therefore it seems sensible to formalize its
   use as the preferred representation of a 4-byte AS.

4.0 Author's Note:

   This proposal was motivated by a discussion with Geoff Huston. The
   text of the definition of a 4-byte AS is taken from [2].

5.0 Security Considerations

   Security considerations are not discussed in this memo.

6.0 Author's  Address:

   George Michaelson
   APNIC
   Level 1, 33 Park Road, Milton, Q4064 Australia

7.0 References

[1] http://www1.ietf.org/internet-drafts/draft-ietf-idr-as4bytes-12.txt
[2] http://www.ripe.net/ripe/policies/proposals/2005-12.html

8.0 Comments & Feedback

Comments are solicited and should be addressed to the working group's
mailing list at idr@ietf.org and/or the author.

9.0 Authors email address

ggm@apnic.net

10.0 Copyright Declaration

Copyright (C) The Internet Society (2006).

This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors retain
all their rights."

"This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR
IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
ENGINEERING TASK FORCE DISCLAIM 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.