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ippm                                                            B. Gafni
Internet-Draft                                                   A. Kfir
Intended status: Standards Track             Mellanox Technologies, Inc.
Expires: September 10, 2019                                  S. Bhandari
                                                            F. Brockners
                                                          R. Sivakolundu
                                                                   Cisco
                                                              T. Mizrahi
                                        Huawei Network.IO Innovation Lab
                                                          March 09, 2019


                        In-situ OAM IPv4 Options
                 draft-gafni-ippm-ioam-ipv4-options-00

Abstract

   In-situ Operations, Administration, and Maintenance (IOAM) records
   operational and telemetry information in the packet while the packet
   traverses a path between two points in the network.  This document
   outlines how IOAM data fields are encapsulated in IPv4.

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 September 10, 2019.

Copyright Notice

   Copyright (c) 2019 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



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   carefully, as they describe your rights and restrictions with respect
   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.  Conventions . . . . . . . . . . . . . . . . . . . . . . . . .   2
     2.1.  Requirements Language . . . . . . . . . . . . . . . . . .   2
     2.2.  Abbreviations . . . . . . . . . . . . . . . . . . . . . .   3
   3.  In-situ OAM Metadata Transport in IPv4  . . . . . . . . . . .   3
     3.1.  Considerations for in-situ OAM in IPv4 options  . . . . .   4
       3.1.1.  Alignment . . . . . . . . . . . . . . . . . . . . . .   4
       3.1.2.  Total available length  . . . . . . . . . . . . . . .   5
       3.1.3.  Pre-allocation vs. Incremental trace types  . . . . .   5
       3.1.4.  Checksum considerations . . . . . . . . . . . . . . .   5
         3.1.4.1.  IP checksum . . . . . . . . . . . . . . . . . . .   5
         3.1.4.2.  TCP checksum  . . . . . . . . . . . . . . . . . .   6
         3.1.4.3.  UDP checksum  . . . . . . . . . . . . . . . . . .   6
       3.1.5.  Fragmentation . . . . . . . . . . . . . . . . . . . .   6
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   6
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   6
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .   7
     6.2.  Informative References  . . . . . . . . . . . . . . . . .   7
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction

   In-situ Operations, Administration, and Maintenance (IOAM) records
   operational and telemetry information in the packet while the packet
   traverses a path between two points in the network.  This document
   outlines how IOAM data fields are encapsulated in the IPv4 [RFC0791].

2.  Conventions

2.1.  Requirements Language

   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.






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2.2.  Abbreviations

   Abbreviations used in this document:

   E2E:       Edge-to-Edge

   IOAM:      In-situ Operations, Administration, and Maintenance

   OAM:       Operations, Administration, and Maintenance

3.  In-situ OAM Metadata Transport in IPv4

   An IPv4 option is defined corresponding to each of the IOAM data
   fields defined in [I-D.ietf-ippm-ioam-data].  These mechanisms of in-
   situ OAM in IPv4 are used to enhance diagnostics of IPv4 networks.
   IOAM is carried in IPv4 packets as a new single option, with an
   option type identifier TBD_IOAM that will be defined by IANA, and
   according to the options definition in [RFC0791].  While specifying a
   new option to carry IOAM data, one may see this as an extension to
   the already defined "record route" and "internet timestamp" options
   in [RFC0791], which allows a packet to record its route and collect
   timestamps throughout the network.  The various IOAM data fields
   defined in [I-D.ietf-ippm-ioam-data] are added as TLVs within the new
   IPv4 option.  In an administrative domain where IOAM is used,
   insertion of the IOAM header in IPv4 is enabled at the IOAM domain
   edge, which serve as IOAM encapsulating/decapsulating nodes by means
   of configuration.

   An IPv4 option format for carrying in-situ OAM data fields:






















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    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |  Option Type  | Option Length |   Reserved    |   IOAM-Type   |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+<-+
    .                                                               .  |
    .                     Option Data                               .  I
    .                                                               .  O
    .                                                               .  A
    .                                                               .  M
    .                                                               .  -
    .                                                               .  O
    .                                                               .  P
    .                                                               .  T
    .                                                               .  I
    .                                                               .  O
    .                                                               .  N
    |                                                               |  |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+<-+


   Option Type:  8-bit identifier of the type of option, consist of: 1
      bit - copied flag, 2 bits - option class, 5 bits - option number.
      For more details see [RFC0791].

   Option Length:  8-bit unsigned integer.  Length of the option
      including the Option Type octet, the Option Length octet, the
      Reserved octet, the IOAM Type octet, and option-data octets.

   Reserved:  8-bits field, reserved for future use.  MUST be zero on
      transmission and ignored on receipt.

   IOAM Type:  8-bit field defining the IOAM Option type, as defined in
      Section 7.2 of [I-D.ietf-ippm-ioam-data].

   Option Data:  Variable-length field, including the IOAM data as
      defined in [I-D.ietf-ippm-ioam-data], in particular see section 4.

3.1.  Considerations for in-situ OAM in IPv4 options

   In the scope of IPv4 header and its options in [RFC0791], there are
   unique considerations for embedding in-situ OAM in the IPv4 options.

3.1.1.  Alignment

   Within an IPv4 options stack there is no requirement for alignment
   outside the octet granularity, which doesn't limit the granularity of
   the in-situ OAM, since it is already 4-octects aligned.





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3.1.2.  Total available length

   There are three fields that may affect the total available length for
   in-situ OAM data to be incorporated in the IPv4 options:

   1.  The IPv4 header's IHL, as described in [RFC0791] in section 3.1:
       This 4-bit field can reach up to 15 times 4 octets, including the
       IPv4 header, which is 20 octets.  This leaves a maximum actual
       length of 40 octets to the options.  Reducing 4 octets for the
       use of the option's header, it leaves 36 octets for the use of
       the in-situ OAM data.  In the context of the trace type, which
       has an 8 octets header, this leaves 28 bytes for actual data to
       be collected during the packet's traverse through the network.

   2.  The option's length, as described here above in section 3: This
       8-bit field can reach up to 255 octets.  Doesn't further restrict
       the in-situ OAM length, because of the above restrictions that
       are already applied.

   3.  Datagram's Total length, as described in [RFC0791] in section
       3.1: Doesn't further restrict the in-situ OAM length, because of
       the above restrictions that are already applied.

3.1.3.  Pre-allocation vs. Incremental trace types

   Considering the IPv4 architecture, and specifically the "record
   route" and "internet timestamp" options definitions, the RFC calls
   for "The size of the option does not change due to adding
   addresses...", and similarly for the timestamp option.  Hence, while
   incorporating In-situ OAM trace type header, an implementation SHOULD
   use one of these two techniques:

   1.  Immediate Export mode, controlled by the I-bit as part of the
       trace flags.

   2.  Pre-allocated trace type as described in section 4.1.1 of
       [I-D.ietf-ippm-ioam-data].

3.1.4.  Checksum considerations

3.1.4.1.  IP checksum

   IPv4 Header Checksum, as described in [RFC0791] MUST be recalculated
   by a device that is updating the In-situ OAM IPv4 option.







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3.1.4.2.  TCP checksum

   TCP's pseudo header, as described in [RFC0793], doesn't include
   neither the IPv4 options nor the IHL, hence doesn't need to be
   recalculated by a device that is adding, removing or updating the in-
   situ OAM IPv4 option.

3.1.4.3.  UDP checksum

   UDP's pseudo header, as described in [RFC0768], doesn't include
   neither the IPv4 options nor the IHL, hence doesn't need to be
   recalculated by a device that is adding, removing or updating the in-
   situ OAM IPv4 option.

3.1.5.  Fragmentation

   Considering the IPv4 architecture, and specifically the "record
   route" and "internet timestamp" options definitions, [RFC0791] is
   calling for setting the option's copy to zero, hence "Not copied on
   fragmentation, goes in first fragment only".  It seems reasonable to
   the authors to keep this idea to prevent duplication of route data
   and maintain similar behavior for the operator, hence an implementer
   SHOULD follow this method.

4.  Security Considerations

   This document describes the encapsulation of IOAM data fields in
   IPv4.  Security considerations of the specific IOAM data fields for
   each case (i.e., Trace, Proof of Transit, and E2E) are described in
   defined in [I-D.ietf-ippm-ioam-data].

   As this document describes a new option for IPv4, that is similar in
   their behavior to an already existing options, the security
   considerations are similar as well to those of [RFC0791].

5.  IANA Considerations

   This draft requests the following IPv4 Option Type assignments from
   sub-registry of Internet Protocol Version 4 (IPv4) Parameters:

   TBD

6.  References








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6.1.  Normative References

   [I-D.ietf-ippm-ioam-data]
              Brockners, F., Bhandari, S., Pignataro, C., Gredler, H.,
              Leddy, J., Youell, S., Mizrahi, T., Mozes, D., Lapukhov,
              P., Chang, R., and d. daniel.bernier@bell.ca, "Data Fields
              for In-situ OAM", draft-ietf-ippm-ioam-data-01 (work in
              progress), October 2017.

   [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>.

6.2.  Informative References

   [RFC0768]  Postel, J., "User Datagram Protocol", STD 6, RFC 768,
              DOI 10.17487/RFC0768, August 1980,
              <https://www.rfc-editor.org/info/rfc768>.

   [RFC0791]  Postel, J., "Internet Protocol", STD 5, RFC 791,
              DOI 10.17487/RFC0791, September 1981,
              <https://www.rfc-editor.org/info/rfc791>.

   [RFC0793]  Postel, J., "Transmission Control Protocol", STD 7,
              RFC 793, DOI 10.17487/RFC0793, September 1981,
              <https://www.rfc-editor.org/info/rfc793>.

Authors' Addresses

   Barak Gafni
   Mellanox Technologies, Inc.
   350 Oakmead Parkway, Suite 100
   Sunnyvale, CA  94085
   U.S.A.

   Email: gbarak@mellanox.com










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   Aviv Kfir
   Mellanox Technologies, Inc.
   350 Oakmead Parkway, Suite 100
   Sunnyvale, CA  94085
   U.S.A.

   Email: avivk@mellanox.com


   Shwetha Bhandari
   Cisco Systems, Inc.
   Cessna Business Park, Sarjapura Marathalli Outer Ring Road
   Bangalore, KARNATAKA 560 087
   India

   Email: shwethab@cisco.com


   Frank Brockners
   Cisco Systems, Inc.
   Hansaallee 249, 3rd Floor
   DUESSELDORF, NORDRHEIN-WESTFALEN  40549
   Germany

   Email: fbrockne@cisco.com


   Ramesh Sivakolundu
   Cisco Systems, Inc.
   170 West Tasman Dr.
   SAN JOSE, CA 95134
   U.S.A.

   Email: sramesh@cisco.com


   Tal Mizrahi
   Huawei Network.IO Innovation Lab
   Israel

   Email: tal.mizrahi.phd@gmail.com










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