Network Working Group                                    F. Templin, Ed.
Internet-Draft                                        The Boeing Company
Intended status: Standards Track                            May 18, 2020
Expires: November 19, 2020


     IPv6 Compressed Routing Header with Variable Length Addresses
                   draft-templin-6man-crh-variable-00

Abstract

   The IPv6 Routing Header can be used to direct a packet through
   multiple intermediate IPv6 waypoints toward a final destination.  In
   its simplest form, the routing header includes the full length of
   each intermediate IPv6 waypoint.  This document specifies a method
   for supporting variable-length compressed IPv6 addresses.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   2
   3.  Requirements  . . . . . . . . . . . . . . . . . . . . . . . .   2
   4.  IPv6 Compressed Routing Header with Variable Length Addresses   2
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   4
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   4
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   4
     8.2.  Informative References  . . . . . . . . . . . . . . . . .   4
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   4

1.  Introduction

   The IPv6 Routing Header [RFC8200] can be used to direct a packet
   through multiple intermediate IPv6 waypoints toward a final
   destination.  In its simplest form, the routing header includes the
   full length of each intermediate IPv6 waypoint.  This document
   specifies a method for supporting variable-length compressed IPv6
   addresses.

2.  Terminology

   The terminology in the normative references applies.

3.  Requirements

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119][RFC8174] when, and only when, they appear in all
   capitals, as shown here.

4.  IPv6 Compressed Routing Header with Variable Length Addresses

   An IPv6 Compressed Routing Header with Variable length addreses is
   shown in Figure 1:












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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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |  Next Header  |  Hdr Ext Len  | Routing Type  | Segments Left |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |T|RSV|  Len[0] |  IPv6 Address[0] (0 to 31 bytes)  .....
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
       |T|RSV|  Len[1] |  IPv6 Address[1] (0 to 31 bytes)  .....
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
       |T|RSV|  Len[2] |  IPv6 Address[2] (0 to 31 bytes)  .....
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
       ...
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
       |T|RSV|  Len[N] |  IPv6 Address[N] [0 to 31 bytes)  .....
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-

       Figure 1: IPv6 Compressed Routing Header with Variable Length
                                 Addresses

   In this format:

   o  Next Header, Hdr Ext Len, Routing Type and Segments Left have the
      same meaning as for other compressed routing header formats.

   o  Immediately following are a set of N type/length/value segments as
      follows:

      *

      *  T indicates whether the following IPv6 Address is compressed on
         the left-side (most significant bits compressed) or right-side
         (least significant bits compressed).

      *  RSV field is reserved for future use.

      *  Len[i] indicates how many contiguous bytes of the left/right
         compressed IPv6 address follow.  Len[i] is a 5-bit field to
         allow for the case that an IPv6 address is accompanied by an
         additional piece of information, e.g., a transport port number.

      *  IPv6 Address[i] is 0 to 31 bits in length, with either left-
         side or right-side compression applied.

   Note that a similar format appears in [RFC8138].







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5.  IANA Considerations

   The IANA is instructed to allocate a routing header type value.

6.  Security Considerations

   Security considerattions are the same as for other compressed routing
   header types.

7.  Acknowledgements

   TBD

8.  References

8.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8200]  Deering, S. and R. Hinden, "Internet Protocol, Version 6
              (IPv6) Specification", STD 86, RFC 8200,
              DOI 10.17487/RFC8200, July 2017,
              <https://www.rfc-editor.org/info/rfc8200>.

8.2.  Informative References

   [RFC8138]  Thubert, P., Ed., Bormann, C., Toutain, L., and R. Cragie,
              "IPv6 over Low-Power Wireless Personal Area Network
              (6LoWPAN) Routing Header", RFC 8138, DOI 10.17487/RFC8138,
              April 2017, <https://www.rfc-editor.org/info/rfc8138>.

Author's Address

   Fred L. Templin (editor)
   The Boeing Company
   P.O. Box 3707
   Seattle, WA  98124
   USA

   Email: fltemplin@acm.org




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