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Versions: 00

Network Working Group                                       F. Brockners
Internet-Draft                                               S. Bhandari
Intended status: Standards Track                             V. Govindan
Expires: May 3, 2018                                        C. Pignataro
                                                                   Cisco
                                                              H. Gredler
                                                            RtBrick Inc.
                                                                J. Leddy
                                                                 Comcast
                                                               S. Youell
                                                                    JMPC
                                                              T. Mizrahi
                                                                 Marvell
                                                                D. Mozes
                                              Mellanox Technologies Ltd.
                                                             P. Lapukhov
                                                                Facebook
                                                                R. Chang
                                                       Barefoot Networks
                                                        October 30, 2017


              VXLAN-GPE Encapsulation for In-situ OAM Data
                   draft-brockners-ioam-vxlan-gpe-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 VXLAN-GPE.

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 http://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 May 3, 2018.



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Copyright Notice

   Copyright (c) 2017 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
   (http://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
   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 . . . . . . . . . . . . . . . . . . . . . . . . .   3
     2.1.  Requirement Language  . . . . . . . . . . . . . . . . . .   3
     2.2.  Abbreviations . . . . . . . . . . . . . . . . . . . . . .   3
   3.  IOAM Data Field Encapsulation in VXLAN-GPE  . . . . . . . . .   3
     3.1.  IOAM Trace Data in VXLAN-GPE  . . . . . . . . . . . . . .   3
     3.2.  IOAM POT Data in VXLAN-GPE  . . . . . . . . . . . . . . .   7
     3.3.  IOAM Edge-to-Edge Data in VXLAN-GPE . . . . . . . . . . .   8
   4.  Discussion of the encapsulation approach  . . . . . . . . . .   9
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  10
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  10
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  11
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  11
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  11
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  12
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  12

1.  Introduction

   In-situ OAM (IOAM) records OAM information within the packet while
   the packet traverses a particular network domain.  The term "in-situ"
   refers to the fact that the IOAM data fields are added to the data
   packets rather than being sent within packets specifically dedicated
   to OAM.  This document defines how IOAM data fields are transported
   as part of the VXLAN-GPE [I-D.ietf-nvo3-vxlan-gpe] encapsulation.
   The IOAM data fields are defined in [I-D.ietf-ippm-ioam-data].  An
   implementation of IOAM which leverages VXLAN-GPE to carry the IOAM
   data is available from the FD.io open source software project
   [FD.io].





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2.  Conventions

2.1.  Requirement Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].

2.2.  Abbreviations

   Abbreviations used in this document:

   IOAM:      In-situ Operations, Administration, and Maintenance

   MTU:       Maximum Transmit Unit

   OAM:       Operations, Administration, and Maintenance

   POT:       Proof of Transit

   SFC:       Service Function Chain

   VXLAN-GPE: Virtual eXtensible Local Area Network, Generic Protocol
              Extension

3.  IOAM Data Field Encapsulation in VXLAN-GPE

   For encapsulating IOAM data fields into VXLAN-GPE
   [I-D.ietf-nvo3-vxlan-gpe] the different IOAM data fields are added as
   options within new IOAM protocol headers in VXLAN-GPE.  In an
   administrative domain where IOAM is used, insertion of the IOAM
   protocol header(s) in VXLAN GPE is enabled at the VXLAN-GPE tunnel
   endpoints which also serve as IOAM encapsulating/decapsulating nodes
   by means of configuration.  The VXLAN-GPE header is defined in
   [I-D.ietf-nvo3-vxlan-gpe].  IOAM specific fields for VXLAN-GPE are
   defined in this document.

3.1.  IOAM Trace Data in VXLAN-GPE

   IOAM tracing data represents data that is inserted at nodes that a
   packet traverses.  To allow for optimal implementations in both
   software as well as hardware forwarders, two different ways to
   encapsulate IOAM data are defined: "Pre-allocated" and "Incremental".
   See [I-D.ietf-ippm-ioam-data] for details on IOAM tracing and the
   pre-allocated and incremental IOAM trace options.

   The packet formats of the pre-allocated IOAM trace and incremental
   IOAM trace when encapsulated in VXLAN-GPE are defined as 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
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                    Outer Ethernet Header                      |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                        Outer IP Header                        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                       Outer UDP Header                        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+--+
 |R|R|Ver|I|P|R|O|          Reserved             |NP=IOAM_Trace  |  |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ GPE
 |     Virtual Network Identifier (VNI)          | Reserved      |  |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+--+
 |      Type     |   IOAM HDR len|    Reserved   | Next Protocol |  |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ IOAM
 |         IOAM-Trace-Type       |NodeLen|  Flags  | Octets-left | Trace
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+<-+
 |                                                               |  |
 |                        node data list [0]                     | IOAM
 |                                                               |  |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+  D
 |                                                               |  a
 |                        node data list [1]                     |  t
 |                                                               |  a
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 ~                             ...                               ~  S
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+  p
 |                                                               |  a
 |                        node data list [n-1]                   |  c
 |                                                               |  e
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+  |
 |                                                               |  |
 |                        node data list [n]                     |  |
 |                                                               |  |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-<--+
 |                                                               |
 |                                                               |
 |                     Payload + Padding (L2/L3/ESP/...)         |
 |                                                               |
 |                                                               |
 |                                                               |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 Pre-allocated Trace Option Data MUST be 4-octet aligned.

      Figure 1: IOAM Pre-allocated Trace Option Format over VXLAN-GPE






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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
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                    Outer Ethernet Header                      |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                        Outer IP Header                        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                       Outer UDP Header                        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+--+
 |R|R|Ver|I|P|R|O|          Reserved             | NP=IOAM_Trace |  |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ GPE
 |     Virtual Network Identifier (VNI)          | Reserved      |  |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+--+
 |      Type     |   IOAM HDR len|    Reserved   | Next Protocol |  |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ IOAM
 |        IOAM-Trace-Type        |NodeLen|  Flags  | Max Length  | Trace
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+<-+
 |                                                               |  |
 |                        node data list [0]                     | IOAM
 |                                                               |  |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+  D
 |                                                               |  a
 |                        node data list [1]                     |  t
 |                                                               |  a
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 ~                             ...                               ~  S
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+  p
 |                                                               |  a
 |                        node data list [n-1]                   |  c
 |                                                               |  e
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+  |
 |                                                               |  |
 |                        node data list [n]                     |  |
 |                                                               |  |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-<--+
 |                                                               |
 |                                                               |
 |                     Payload + Padding (L2/L3/ESP/...)         |
 |                                                               |
 |                                                               |
 |                                                               |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 IOAM Incremental Trace Option Data MUST be 4-octet aligned.

       Figure 2: IOAM Incremental Trace Option Format over VXLAN-GPE

   The IOAM Trace header consists of 8 octets, as illustrated in
   Figure 1 and Figure 2.  The format of the first 4 octets (Figure 3)



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   is specific to VXLAN-GPE, and is defined in this document.  The
   format of the next 4 octets (trace option header) is defined in
   [I-D.ietf-ippm-ioam-data], and is described here for the sake of
   clarity.

    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     |   IOAM HDR len|    Reserved   | Next Protocol |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                 Figure 3: Trace Shim Header for VXLAN-GPE

   The fields of the trace shim header are as follows:

   Type:  8-bit unsigned integer defining IOAM header type
      IOAM_TRACE_Preallocated or IOAM_Trace_Incremental are defined
      here.

   IOAM HDR len:  8-bit unsigned integer.  Length of the IOAM HDR in
      4-octet units.

   Reserved:  8-bit reserved field MUST be set to zero.

   Next Protocol:  8-bit unsigned integer that determines the type of
      header following IOAM protocol.  The value is from the IANA
      registry setup for VXLAN GPE Next Protocol defined in
      [I-D.ietf-nvo3-vxlan-gpe].

   The fields of the trace option header [I-D.ietf-ippm-ioam-data] are
   as follows:

   IOAM-Trace-Type:  16-bit identifier of IOAM Trace Type as defined in
      [I-D.ietf-ippm-ioam-data] IOAM-Trace-Types.

   Node Data Length:  4-bit unsigned integer as defined in
      [I-D.ietf-ippm-ioam-data].

   Flags:  5-bit field as defined in [I-D.ietf-ippm-ioam-data].

   Octets-left:  7-bit unsigned integer as defined in
      [I-D.ietf-ippm-ioam-data].

   Maximum-length:  7-bit unsigned integer as defined in
      [I-D.ietf-ippm-ioam-data].

   Node data List [n]:  Variable-length field as defined in
      [I-D.ietf-ippm-ioam-data].



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3.2.  IOAM POT Data in VXLAN-GPE

   IOAM proof of transit (POT, see also
   [I-D.brockners-proof-of-transit]) offers a means to verify that a
   packet has traversed a defined set of nodes.  IOAM POT data fields
   are encapsulated in VXLAN-GPE using a dedicated VXLAN-GPE protocol
   header:

   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
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |                    Outer Ethernet Header                      |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |                        Outer IP Header                        |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |                       Outer UDP Header                        |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+--+
  |R|R|Ver|I|P|R|O|          Reserved(MBZ)        |NP = IOAM_POT  |  |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ GPE
  |     Virtual Network Identifier (VNI)          | Reserved      |  |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+--+
  |IOAM POT Type|P|   IOAM HDR len|    Reserved   | Next Protocol |  |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ IOAM
  |                           Random                              |  |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+  P
  |                        Random(contd.)                         |  O
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+  T
  |                         Cumulative                            |  |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+  |
  |                    Cumulative (contd.)                        |  |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+<-+

         Figure 4: IOAM POT Header Following the VXLAN-GPE Header

   The IOAM POT Shim Header (Figure 5), which is defined in this
   document, is a 4-octet header, that includes the following fields:

   IOAM POT Type:  7-bit identifier of a particular POT variant that
      specifies the POT data that is to be included as defined in
      [I-D.ietf-ippm-ioam-data].

   Profile to use (P):  1-bit as defined in [I-D.ietf-ippm-ioam-data]
      IOAM POT Option.

   IOAM HDR len:  8-bit unsigned integer.  Length of the IOAM HDR in
      4-octet units.

   Reserved:  8-bit reserved field MUST be set to zero.



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   Next Protocol:  8-bit unsigned integer that determines the type of
      header following IOAM protocol.  The value is from the IANA
      registry setup for VXLAN GPE Next Protocol defined in
      [I-D.ietf-nvo3-vxlan-gpe].

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |IOAM POT Type|P|   IOAM HDR len|    Reserved   | Next Protocol |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                  Figure 5: POT Shim Header for VXLAN-GPE

   The rest of the fields in the POT option [I-D.ietf-ippm-ioam-data]
   are as follows:

   Random:  64-bit Per-packet random number.

   Cumulative:  64-bit Cumulative value that is updated by the Service
      Functions.

3.3.  IOAM Edge-to-Edge Data in VXLAN-GPE

   The IOAM edge-to-edge option is to carry data that is added by the
   IOAM encapsulating node and interpreted by the IOAM decapsulating
   node.  IOAM specific fields to encapsulate IOAM Edge-to-Edge data
   fields are defined as follows:

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                    Outer Ethernet Header                      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        Outer IP Header                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       Outer UDP Header                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+--+
   |R|R|Ver|I|P|R|O|          Reserved             |NP = IOAM_E2E  |  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ GPE
   |     Virtual Network Identifier (VNI)          | Reserved      |  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+--+
   |Type=IOAM_E2E  |   IOAM HDR len  |  Reserved   | Next Protocol |  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+IOAM
   |      E2E Option data field determined by IOAM-E2E-Type        |  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+<-+

            Figure 6: IOAM Edge-to-Edge over a VXLAN-GPE Header




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   The IOAM E2E Shim Header, which is defined in this document, is a
   4-octet header, that includes the following fields:

   Type:  8-bit identifier of a particular E2E variant that specifies
      the E2E data that is to be included as defined in
      [I-D.ietf-ippm-ioam-data].

   IOAM HDR len:  8-bit unsigned integer.  Length of the IOAM HDR in
      4-octet units.

   Reserved:  8-bit reserved field MUST be set to zero.

   Next Protocol:  8-bit unsigned integer that determines the type of
      header following IOAM protocol.  The value is from the IANA
      registry setup for VXLAN GPE Next Protocol defined in
      [I-D.ietf-nvo3-vxlan-gpe].

    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=IOAM_E2E  |   IOAM HDR len  |  Reserved   | Next Protocol |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                  Figure 7: E2E Shim Header for VXLAN-GPE

   The rest of the E2E option [I-D.ietf-ippm-ioam-data] consists of:

   E2E Option data field:  Variable length field as defined in
      [I-D.ietf-ippm-ioam-data] IOAM E2E Option.

4.  Discussion of the encapsulation approach

   This section is to support the working group discussion in selecting
   the most appropriate approach for encapsulating IOAM data fields in
   VXLAN-GPE.

   An encapsulation of IOAM data fields in VXLAN-GPE should be friendly
   to an implementation in both hardware as well as software forwarders.
   Hardware forwarders benefit from an encapsulation that minimizes
   iterative look-ups of fields within the packet: Any operation which
   looks up the value of a field within the packet, based on which
   another lookup is performed, consumes additional gates and time in an
   implementation - both of which are desired to be kept to a minimum.
   This means that flat TLV structures are to be preferred over nested
   TLV structures.  IOAM data fields are grouped into three option
   categories: Trace, proof-of-transit, and edge-to-edge.  Each of these
   three options defines a TLV structure.  A hardware-friendly
   encapsulation approach avoids grouping these three option categories



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   into yet another TLV structure, but would rather carry the options as
   a serial sequence.

   Two approaches for encapsulating IOAM data fields in VXLAN-GPE could
   be considered:

   1.  Use a single GPE protocol type for all IOAM types: IOAM would
       receive a single GPE protocol type code point.  A "sub-type"
       (e.g. 4 bit wide) would then specify what IOAM options type(s)
       (trace, proof-of-transit, edge-to-edge) are carried.  In case
       there is a need for additional IOAM options, changes would be
       contained within the single GPE protocol type for IOAM.

   2.  Use one GPE protocol type per IOAM options type: Each IOAM data
       field option (trace, proof-of-transit, and edge-to-edge) would be
       specified by its own "next protocol", i.e. each IOAM options type
       becomes its own GPE protocol type with a dedicated code point.
       This implies that in case additional IOAM option types would be
       added in the future, additional GPE protocol type code points
       would need to be allocated.

   The second option has been chosen here, because it avoids the
   additional layer of TLV nesting that the use of a single GPE protocol
   type for all IOAM option types would result in.

5.  IANA Considerations

   IANA is requested to allocate protocol numbers for the following
   VXLAN-GPE "Next Protocols" related to IOAM:

                 +---------------+-------------+---------------+
                 | Next Protocol | Description | Reference     |
                 +---------------+-------------+---------------+
                 | x             | IOAM_Trace  | This document |
                 | y             | IOAM_POT    | This document |
                 | z             | IOAM_E2E    | This document |
                 +---------------+-------------+---------------+


6.  Security Considerations

   The security considerations of VXLAN-GPE are discussed in
   [I-D.ietf-nvo3-vxlan-gpe], and the security considerations of IOAM in
   general are discussed in [I-D.ietf-ippm-ioam-data].

   IOAM is considered a "per domain" feature, where one or several
   operators decide on leveraging and configuring IOAM according to
   their needs.  Still, operators need to properly secure the IOAM



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   domain to avoid malicious configuration and use, which could include
   injecting malicious IOAM packets into a domain.

7.  Acknowledgements

   The authors would like to thank Eric Vyncke, Nalini Elkins, Srihari
   Raghavan, Ranganathan T S, Karthik Babu Harichandra Babu, Akshaya
   Nadahalli, Stefano Previdi, Hemant Singh, Erik Nordmark, LJ Wobker,
   and Andrew Yourtchenko for the comments and advice.

8.  References

8.1.  Normative References

   [ETYPES]   "IANA Ethernet Numbers",
              <https://www.iana.org/assignments/ethernet-numbers/
              ethernet-numbers.xhtml>.

   [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-00 (work in
              progress), September 2017.

   [I-D.ietf-nvo3-vxlan-gpe]
              Maino, F., Kreeger, L., and U. Elzur, "Generic Protocol
              Extension for VXLAN", draft-ietf-nvo3-vxlan-gpe-04 (work
              in progress), April 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>.

   [RFC2784]  Farinacci, D., Li, T., Hanks, S., Meyer, D., and P.
              Traina, "Generic Routing Encapsulation (GRE)", RFC 2784,
              DOI 10.17487/RFC2784, March 2000, <https://www.rfc-
              editor.org/info/rfc2784>.

   [RFC3232]  Reynolds, J., Ed., "Assigned Numbers: RFC 1700 is Replaced
              by an On-line Database", RFC 3232, DOI 10.17487/RFC3232,
              January 2002, <https://www.rfc-editor.org/info/rfc3232>.








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8.2.  Informative References

   [FD.io]    "Fast Data Project: FD.io", <https://fd.io/>.

   [I-D.brockners-proof-of-transit]
              Brockners, F., Bhandari, S., Dara, S., Pignataro, C.,
              Leddy, J., Youell, S., Mozes, D., and T. Mizrahi, "Proof
              of Transit", draft-brockners-proof-of-transit-03 (work in
              progress), March 2017.

   [RFC7665]  Halpern, J., Ed. and C. Pignataro, Ed., "Service Function
              Chaining (SFC) Architecture", RFC 7665,
              DOI 10.17487/RFC7665, October 2015, <https://www.rfc-
              editor.org/info/rfc7665>.

Authors' Addresses

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

   Email: fbrockne@cisco.com


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

   Email: shwethab@cisco.com


   Vengada Prasad Govindan
   Cisco Systems, Inc.

   Email: venggovi@cisco.com


   Carlos Pignataro
   Cisco Systems, Inc.
   7200-11 Kit Creek Road
   Research Triangle Park, NC  27709
   United States

   Email: cpignata@cisco.com



Brockners, et al.          Expires May 3, 2018                 [Page 12]


Internet-Draft     In-situ OAM VXLAN-GPE encapsulation      October 2017


   Hannes Gredler
   RtBrick Inc.

   Email: hannes@rtbrick.com


   John Leddy
   Comcast

   Email: John_Leddy@cable.comcast.com


   Stephen Youell
   JP Morgan Chase
   25 Bank Street
   London  E14 5JP
   United Kingdom

   Email: stephen.youell@jpmorgan.com


   Tal Mizrahi
   Marvell
   6 Hamada St.
   Yokneam  20692
   Israel

   Email: talmi@marvell.com


   David Mozes
   Mellanox Technologies Ltd.

   Email: davidm@mellanox.com


   Petr Lapukhov
   Facebook
   1 Hacker Way
   Menlo Park, CA  94025
   US

   Email: petr@fb.com








Brockners, et al.          Expires May 3, 2018                 [Page 13]


Internet-Draft     In-situ OAM VXLAN-GPE encapsulation      October 2017


   Remy Chang
   Barefoot Networks
   2185 Park Boulevard
   Palo Alto, CA  94306
   US














































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