[Docs] [txt|pdf|xml] [Tracker] [Email] [Diff1] [Diff2] [Nits]

Versions: 00 01 02 03 04 05 06 07

Network Working Group                                    F. Templin, Ed.
Internet-Draft                                        The Boeing Company
Intended status: Standards Track                               A. Whyman
Expires: June 3, 2021                    MWA Ltd c/o Inmarsat Global Ltd
                                                       November 30, 2020


   IPv6 Neighbor Discovery Overlay Multilink Network Interface (OMNI)
                                 Option
                   draft-templin-6man-omni-option-03

Abstract

   This document defines a new IPv6 Neighbor Discovery (ND) option
   termed the "Overlay Multilink Network Interface (OMNI) Option".  The
   OMNI option may appear in any IPv6 ND message type; it is processed
   by interface types that recognize the option and ignored by all other
   interface types.  The option supports functions such as prefix
   registration and multilink coordination, and is extensible to support
   additional functions in the future.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   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."

   This Internet-Draft will expire on June 3, 2021.

Copyright Notice

   Copyright (c) 2020 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect



Templin & Whyman          Expires June 3, 2021                  [Page 1]


Internet-Draft             IPv6 ND OMNI Option             November 2020


   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   2
   3.  The Overlay Multilink Network Interface (OMNI) IPv6 ND Option   3
     3.1.  Sub-Options . . . . . . . . . . . . . . . . . . . . . . .   4
       3.1.1.  Pad1  . . . . . . . . . . . . . . . . . . . . . . . .   5
       3.1.2.  PadN  . . . . . . . . . . . . . . . . . . . . . . . .   5
       3.1.3.  Interface Attributes (Type 1) . . . . . . . . . . . .   6
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   7
   6.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   7
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   7
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .   8
     7.2.  Informative References  . . . . . . . . . . . . . . . . .   8
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   8

1.  Introduction

   This document defines a new IPv6 Neighbor Discovery (ND) option
   termed the "Overlay Multilink Network Interface (OMNI) Option".  The
   OMNI option may appear in any IPv6 ND message type; it is processed
   by interface types that recognize the option and ignored by all other
   interface types.  The option supports functions such as prefix
   registration and multilink coordination for interface types such as
   the OMNI interface [I-D.templin-6man-omni-interface], and is
   extensible to support additional functions in the future.

   The following sections discuss the OMNI option format and contents.
   Uses for the option are specified in IPv6 over specific link layer
   documents such as [I-D.templin-6man-omni-interface].  An IPv6 ND
   option Type number assignment is requested in the IANA Considerations
   section.

2.  Terminology

   The terminology in the normative references applies.  The term
   "underlying interface" refers to one of potentially multiple Layer-2
   interfaces over which a Layer-3 (virtual) interface is configured.

   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



Templin & Whyman          Expires June 3, 2021                  [Page 2]


Internet-Draft             IPv6 ND OMNI Option             November 2020


   14 [RFC2119][RFC8174] when, and only when, they appear in all
   capitals, as shown here.

3.  The Overlay Multilink Network Interface (OMNI) IPv6 ND Option

   An Overlay Multilink Network Interface (OMNI) IPv6 ND option is
   defined.  The option (known as the "OMNI option") is formatted as
   shown in Figure 1:

        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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |      Type     |     Length    |T|   Preflen   | S/T-omIndex   |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                                                               |
       ~                          Sub-Options                          ~
       |                                                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                       Figure 1: OMNI Option Format

   In this format:

   o  Type is set to TBD.

   o  Length is set to the number of 8 octet blocks in the option.

   o  T is a 1-bit flag set to 1 if an address is temporary (otherwise,
      set to 0) and Preflen is a 7 bit field that determines the length
      of prefix to be applied to an address.  Values 1 through 127
      specify a prefix length, while the value 0 indicates a singleton
      address (i.e., a /128).  For IPv6 ND messages sent from a node to
      a router, T and Preflen apply to the IPv6 source address.  For
      IPv6 ND messages sent from the router to the node, T and Preflen
      apply to the IPv6 destination address.

   o  S/T-omIndex is a 1-octet field that encodes a value between 0 and
      255 identifying the source or target underlying interface for the
      IPv6 ND message.  For RS and NS messages S/T-omIndex refers to the
      "Source" underlying interface over which the message is sent,
      while for RA and NA messages S/T-omIndex refers to the "Target"
      underlying interface that will receive the message.

   o  Sub-Options is a Variable-length field, of length such that the
      complete OMNI Option is an integer multiple of 8 octets long.
      Contains one or more Sub-Options, as described in Section 3.1.





Templin & Whyman          Expires June 3, 2021                  [Page 3]


Internet-Draft             IPv6 ND OMNI Option             November 2020


   The OMNI option may appear in any IPv6 ND message type; it is
   processed by interfaces that recognize the option and ignored by all
   other interfaces.  If a single IPv6 ND message contains multiple OMNI
   options, the first option is processed and any additional options are
   ignored.

   An OMNI option may include full or partial information for the
   neighbor.  If an OMNI option with full information is received, its
   contents provide new information and/or update any previously cached
   information.  If an OMNI option with partial information is received,
   it contents provide new information and/or update only the
   corresponding previously cached information.  The union of the
   information in the most recently received OMNI options is therefore
   retained, and the information is aged/removed in conjunction with the
   corresponding neighbor cache entry.

3.1.  Sub-Options

   The OMNI option includes zero or more Sub-Options.  Each consecutive
   Sub-Option is concatenated immediately after its predecessor.  All
   Sub-Options except Pad1 (see below) are in type-length-value (TLV)
   encoded in the following format:

         0                   1                   2
         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
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
        |   Sub-Type    |  Sub-length   | Sub-Option Data ...
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-

                        Figure 2: Sub-Option Format

   o  Sub-Type is a 1-octet field that encodes the Sub-Option type.
      Sub-Options defined in this document are:

        Option Name               Sub-Type
        Pad1                           0
        PadN                           1
        Interface Attributes (Type 1)  2

                                 Figure 3

      Sub-Types 253 and 254 are reserved for experimentation; Sub-Type
      255 is reserved by IANA.

   o  Sub-Length is a 1-octet field that encodes the length of the Sub-
      Option Data (i.e., ranging from 0 to 255 octets).





Templin & Whyman          Expires June 3, 2021                  [Page 4]


Internet-Draft             IPv6 ND OMNI Option             November 2020


   o  Sub-Option Data is a block of data with format determined by Sub-
      Type.

   During processing, unrecognized Sub-Options are ignored and the next
   Sub-Option processed until the end of the OMNI option is reached.

   The following Sub-Option types and formats are defined in this
   document (note that other documents that are active at the time of
   this writing will define additional Sub-Option types in the near
   future):

3.1.1.  Pad1

         0
         0 1 2 3 4 5 6 7
        +-+-+-+-+-+-+-+-+
        |   Sub-Type=0  |
        +-+-+-+-+-+-+-+-+

                              Figure 4: Pad1

   o  Sub-Type is set to 0.  If multiple instances appear in the same
      OMNI option all are processed.

   o  No Sub-Length or Sub-Option Data follows (i.e., the "Sub-Option"
      consists of a single zero octet).

3.1.2.  PadN

         0                   1                   2
         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
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
        |   Sub-Type=1  | Sub-length=N  | N padding octets ...
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-

                              Figure 5: PadN

   o  Sub-Type is set to 1.  If multiple instances appear in the same
      OMNI option all are processed.

   o  Sub-Length is set to N (from 0 to 255) being the number of padding
      octets that follow.

   o  Sub-Option Data consists of N padding octets that are typically
      zero-valued (any non-zero values that may appear in the padding
      octets are not to be interpreted in any way other than as simple
      padding).




Templin & Whyman          Expires June 3, 2021                  [Page 5]


Internet-Draft             IPv6 ND OMNI Option             November 2020


3.1.3.  Interface Attributes (Type 1)

        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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |   Sub-Type=2  | Sub-length=N  |    omIndex    |    omType     |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |  Provider ID  | Link  | Resvd |P00|P01|P02|P03|P04|P05|P06|P07|
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |P08|P09|P10|P11|P12|P13|P14|P15|P16|P17|P18|P19|P20|P21|P22|P23|
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |P24|P25|P26|P27|P28|P29|P30|P31|P32|P33|P34|P35|P36|P37|P38|P39|
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |P40|P41|P42|P43|P44|P45|P46|P47|P48|P49|P50|P51|P52|P53|P54|P55|
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |P56|P57|P58|P59|P60|P61|P62|P63|
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                  Figure 6: Interface Attributes (Type 1)

   o  Sub-Type is set to 2.  If multiple instances with different
      omIndex values appear in the same OMNI option all are processed;
      if multiple instances with the same omIndex value appear, the
      first is processed and all others are ignored

   o  Sub-Length is set to N (from 1 to 255) that encodes the number of
      Sub-Option Data octets that follow.

   o  omIndex is a 1-octet field containing a value from 0 to 255
      identifying the underlying interface for which the interface
      attributes apply.

   o  omType is a 1-octet field containing a value from 0 to 255
      corresponding to the underlying interface identified by omIndex.

   o  Provider ID is a 1-octet field containing a value from 0 to 255
      corresponding to the underlying interface identified by omIndex.

   o  Link encodes a 4-bit link metric.  The value '0' means the link is
      DOWN, and the remaining values mean the link is UP with metric
      ranging from '1' ("lowest") to '15' ("highest").

   o  Resvd is reserved for future use.

   o  A 16-octet ""Preferences" field immediately follows 'Resvd', with
      values P[00] through P[63] corresponding to the 64 Differentiated
      Service Code Point (DSCP) values [RFC2474].  Each 2-bit P[*] field
      is set to the value '0' ("disabled"), '1' ("low"), '2' ("medium")



Templin & Whyman          Expires June 3, 2021                  [Page 6]


Internet-Draft             IPv6 ND OMNI Option             November 2020


      or '3' ("high") to indicate a QoS preference for underlying
      interface selection purposes.

4.  IANA Considerations

   The IANA is instructed to allocate a Type number TBD from the
   registry "IPv6 Neighbor Discovery Option Formats" for the OMNI option
   (see: Section 13 of [RFC4861]) as a provisional registration in
   accordance with Section 4.13 of [RFC8126].

   The OMNI option also defines an 8-bit Sub-Type field, for which IANA
   is instructed to create and maintain a new registry entitled "OMNI
   option Sub-Type values".  Initial values for the OMNI option Sub-Type
   values registry are given below; future assignments are to be made
   through Expert Review [RFC8126].

      Value    Sub-Type name                  Reference
      -----    -------------                  ----------
      0        Pad1                           [RFCXXXX]
      1        PadN                           [RFCXXXX]
      2        Interface Attributes (Type 1)  [RFCXXXX]
      3-252    Unassigned
      253-254  Experimental                   [RFCXXXX]
      255      Reserved                       [RFCXXXX]

                   Figure 7: OMNI Option Sub-Type Values

5.  Security Considerations

   Security considerations for IPv6 [RFC8200] and IPv6 Neighbor
   Discovery [RFC4861] apply.

6.  Acknowledgements

   This document is aligned with the International Civil Aviation
   Organization (ICAO) Aeronautical Telecommunications Network (ATN)
   with Internet Protocol Services (ATN/IPS) development program.  The
   document supports ICAO Document 9896 Draft Edition 3 (work-in-
   progress).

   This document is aligned with the IETF 6man (IPv6) working group.

7.  References








Templin & Whyman          Expires June 3, 2021                  [Page 7]


Internet-Draft             IPv6 ND OMNI Option             November 2020


7.1.  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>.

   [RFC4861]  Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
              "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
              DOI 10.17487/RFC4861, September 2007,
              <https://www.rfc-editor.org/info/rfc4861>.

   [RFC8126]  Cotton, M., Leiba, B., and T. Narten, "Guidelines for
              Writing an IANA Considerations Section in RFCs", BCP 26,
              RFC 8126, DOI 10.17487/RFC8126, June 2017,
              <https://www.rfc-editor.org/info/rfc8126>.

   [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>.

7.2.  Informative References

   [I-D.templin-6man-omni-interface]
              Templin, F. and T. Whyman, "Transmission of IP Packets
              over Overlay Multilink Network (OMNI) Interfaces", draft-
              templin-6man-omni-interface-51 (work in progress),
              November 2020.

   [RFC2474]  Nichols, K., Blake, S., Baker, F., and D. Black,
              "Definition of the Differentiated Services Field (DS
              Field) in the IPv4 and IPv6 Headers", RFC 2474,
              DOI 10.17487/RFC2474, December 1998,
              <https://www.rfc-editor.org/info/rfc2474>.

Authors' Addresses










Templin & Whyman          Expires June 3, 2021                  [Page 8]


Internet-Draft             IPv6 ND OMNI Option             November 2020


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

   Email: fltemplin@acm.org


   Tony Whyman
   MWA Ltd c/o Inmarsat Global Ltd
   99 City Road
   London  EC1Y 1AX
   England

   Email: tony.whyman@mccallumwhyman.com



































Templin & Whyman          Expires June 3, 2021                  [Page 9]


Html markup produced by rfcmarkup 1.129d, available from https://tools.ietf.org/tools/rfcmarkup/