<?xml version='1.0' encoding='utf-8'?>
<rfc xmlns:xi="http://www.w3.org/2001/XInclude" version="3" category="info" consensus="true" docName="draft-ietf-bess-evpn-oam-req-frmwk-10" indexInclude="true" ipr="trust200902" number="9062" prepTime="2021-06-30T18:22:08" scripts="Common,Latin" sortRefs="true" submissionType="IETF" symRefs="true" tocDepth="5" tocInclude="true" xml:lang="en">
  <link href="https://datatracker.ietf.org/doc/draft-ietf-bess-evpn-oam-req-frmwk-10" rel="prev"/>
  <link href="https://dx.doi.org/10.17487/rfc9062" rel="alternate"/>
  <link href="urn:issn:2070-1721" rel="alternate"/>
  <front>
    <title abbrev="EVPN OAM Requirements/Framework">Framework and Requirements for Ethernet VPN (EVPN) Operations, Administration, and Maintenance (OAM)</title>
    <seriesInfo name="RFC" value="9062" stream="IETF"/>
    <author initials="S." surname="Salam" fullname="Samer Salam">
      <organization showOnFrontPage="true">Cisco</organization>
      <address>
        <postal>
          <street>The Atrium Building, Floor 3</street>
          <street>Weygand St.</street>
          <city>Beirut</city>
          <region/>
          <code/>
          <country>Lebanon</country>
        </postal>
        <email>ssalam@cisco.com</email>
      </address>
    </author>
    <author initials="A." surname="Sajassi" fullname="Ali Sajassi">
      <organization showOnFrontPage="true">Cisco</organization>
      <address>
        <postal>
          <street>170 West Tasman Drive</street>
          <city>San Jose</city>
          <region>CA</region>
          <code>95134</code>
          <country>United States of America</country>
        </postal>
        <email>sajassi@cisco.com</email>
      </address>
    </author>
    <author initials="S." surname="Aldrin" fullname="Sam Aldrin">
      <organization abbrev="Google" showOnFrontPage="true">Google, Inc.</organization>
      <address>
        <postal>
          <street>1600 Amphitheatre Parkway</street>
          <city>Mountain View</city>
          <region>CA</region>
          <code>94043</code>
          <country>United States of America</country>
        </postal>
        <email>aldrin.ietf@gmail.com</email>
      </address>
    </author>
    <author initials="J." surname="Drake" fullname="John E. Drake">
      <organization abbrev="Juniper" showOnFrontPage="true">Juniper Networks</organization>
      <address>
        <postal>
          <street>1194 N. Mathilda Ave.</street>
          <city>Sunnyvale</city>
          <region>CA</region>
          <code>94089</code>
          <country>United States of America</country>
        </postal>
        <email>jdrake@juniper.net</email>
      </address>
    </author>
    <author initials="D." surname="Eastlake 3rd" fullname="Donald E. Eastlake 3rd">
      <organization abbrev="Futurewei" showOnFrontPage="true">Futurewei Technologies</organization>
      <address>
        <postal>
          <street>2386 Panoramic Circle</street>
          <city>Apopka</city>
          <region>FL</region>
          <code>32703</code>
          <country>United States of America</country>
        </postal>
        <phone>+1-508-333-2270</phone>
        <email>d3e3e3@gmail.com</email>
      </address>
    </author>
    <date month="06" year="2021"/>
    <keyword>PBB-EVPN</keyword>
    <keyword>fault management</keyword>
    <keyword>performance management</keyword>
    <abstract pn="section-abstract">
      <t indent="0" pn="section-abstract-1">
   This document specifies the requirements and reference framework for
   Ethernet VPN (EVPN) Operations, Administration, and Maintenance (OAM).
   The requirements cover the OAM aspects of EVPN and Provider Backbone Bridge EVPN (PBB-EVPN).  The framework defines the layered OAM model
   encompassing the EVPN service layer, network layer, underlying Packet
   Switched Network (PSN) transport layer, and link layer but focuses on
   the service and network layers.</t>
    </abstract>
    <boilerplate>
      <section anchor="status-of-memo" numbered="false" removeInRFC="false" toc="exclude" pn="section-boilerplate.1">
        <name slugifiedName="name-status-of-this-memo">Status of This Memo</name>
        <t indent="0" pn="section-boilerplate.1-1">
            This document is not an Internet Standards Track specification; it is
            published for informational purposes.  
        </t>
        <t indent="0" pn="section-boilerplate.1-2">
            This document is a product of the Internet Engineering Task Force
            (IETF).  It represents the consensus of the IETF community.  It has
            received public review and has been approved for publication by the
            Internet Engineering Steering Group (IESG).  Not all documents
            approved by the IESG are candidates for any level of Internet
            Standard; see Section 2 of RFC 7841. 
        </t>
        <t indent="0" pn="section-boilerplate.1-3">
            Information about the current status of this document, any
            errata, and how to provide feedback on it may be obtained at
            <eref target="https://www.rfc-editor.org/info/rfc9062" brackets="none"/>.
        </t>
      </section>
      <section anchor="copyright" numbered="false" removeInRFC="false" toc="exclude" pn="section-boilerplate.2">
        <name slugifiedName="name-copyright-notice">Copyright Notice</name>
        <t indent="0" pn="section-boilerplate.2-1">
            Copyright (c) 2021 IETF Trust and the persons identified as the
            document authors. All rights reserved.
        </t>
        <t indent="0" pn="section-boilerplate.2-2">
            This document is subject to BCP 78 and the IETF Trust's Legal
            Provisions Relating to IETF Documents
            (<eref target="https://trustee.ietf.org/license-info" brackets="none"/>) 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.
        </t>
      </section>
    </boilerplate>
    <toc>
      <section anchor="toc" numbered="false" removeInRFC="false" toc="exclude" pn="section-toc.1">
        <name slugifiedName="name-table-of-contents">Table of Contents</name>
        <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1">
          <li pn="section-toc.1-1.1">
            <t indent="0" pn="section-toc.1-1.1.1"><xref derivedContent="1" format="counter" sectionFormat="of" target="section-1"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-introduction">Introduction</xref></t>
            <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.1.2">
              <li pn="section-toc.1-1.1.2.1">
                <t indent="0" keepWithNext="true" pn="section-toc.1-1.1.2.1.1"><xref derivedContent="1.1" format="counter" sectionFormat="of" target="section-1.1"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-relationship-to-other-oam-w">Relationship to Other OAM Work</xref></t>
              </li>
              <li pn="section-toc.1-1.1.2.2">
                <t indent="0" keepWithNext="true" pn="section-toc.1-1.1.2.2.1"><xref derivedContent="1.2" format="counter" sectionFormat="of" target="section-1.2"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-specification-of-requiremen">Specification of Requirements</xref></t>
              </li>
              <li pn="section-toc.1-1.1.2.3">
                <t indent="0" keepWithNext="true" pn="section-toc.1-1.1.2.3.1"><xref derivedContent="1.3" format="counter" sectionFormat="of" target="section-1.3"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-terminology">Terminology</xref></t>
              </li>
            </ul>
          </li>
          <li pn="section-toc.1-1.2">
            <t indent="0" pn="section-toc.1-1.2.1"><xref derivedContent="2" format="counter" sectionFormat="of" target="section-2"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-evpn-oam-framework">EVPN OAM Framework</xref></t>
            <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.2.2">
              <li pn="section-toc.1-1.2.2.1">
                <t indent="0" pn="section-toc.1-1.2.2.1.1"><xref derivedContent="2.1" format="counter" sectionFormat="of" target="section-2.1"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-oam-layering">OAM Layering</xref></t>
              </li>
              <li pn="section-toc.1-1.2.2.2">
                <t indent="0" pn="section-toc.1-1.2.2.2.1"><xref derivedContent="2.2" format="counter" sectionFormat="of" target="section-2.2"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-evpn-service-oam">EVPN Service OAM</xref></t>
              </li>
              <li pn="section-toc.1-1.2.2.3">
                <t indent="0" pn="section-toc.1-1.2.2.3.1"><xref derivedContent="2.3" format="counter" sectionFormat="of" target="section-2.3"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-evpn-network-oam">EVPN Network OAM</xref></t>
              </li>
              <li pn="section-toc.1-1.2.2.4">
                <t indent="0" pn="section-toc.1-1.2.2.4.1"><xref derivedContent="2.4" format="counter" sectionFormat="of" target="section-2.4"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-transport-oam-for-evpn">Transport OAM for EVPN</xref></t>
              </li>
              <li pn="section-toc.1-1.2.2.5">
                <t indent="0" pn="section-toc.1-1.2.2.5.1"><xref derivedContent="2.5" format="counter" sectionFormat="of" target="section-2.5"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-link-oam">Link OAM</xref></t>
              </li>
              <li pn="section-toc.1-1.2.2.6">
                <t indent="0" pn="section-toc.1-1.2.2.6.1"><xref derivedContent="2.6" format="counter" sectionFormat="of" target="section-2.6"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-oam-interworking">OAM Interworking</xref></t>
              </li>
            </ul>
          </li>
          <li pn="section-toc.1-1.3">
            <t indent="0" pn="section-toc.1-1.3.1"><xref derivedContent="3" format="counter" sectionFormat="of" target="section-3"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-evpn-oam-requirements">EVPN OAM Requirements</xref></t>
            <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.3.2">
              <li pn="section-toc.1-1.3.2.1">
                <t indent="0" pn="section-toc.1-1.3.2.1.1"><xref derivedContent="3.1" format="counter" sectionFormat="of" target="section-3.1"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-fault-management-requiremen">Fault Management Requirements</xref></t>
                <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.3.2.1.2">
                  <li pn="section-toc.1-1.3.2.1.2.1">
                    <t indent="0" pn="section-toc.1-1.3.2.1.2.1.1"><xref derivedContent="3.1.1" format="counter" sectionFormat="of" target="section-3.1.1"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-proactive-fault-management-">Proactive Fault Management Functions</xref></t>
                    <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.3.2.1.2.1.2">
                      <li pn="section-toc.1-1.3.2.1.2.1.2.1">
                        <t indent="0" pn="section-toc.1-1.3.2.1.2.1.2.1.1"><xref derivedContent="3.1.1.1" format="counter" sectionFormat="of" target="section-3.1.1.1"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-fault-detection-continuity-">Fault Detection (Continuity Check)</xref></t>
                      </li>
                      <li pn="section-toc.1-1.3.2.1.2.1.2.2">
                        <t indent="0" pn="section-toc.1-1.3.2.1.2.1.2.2.1"><xref derivedContent="3.1.1.2" format="counter" sectionFormat="of" target="section-3.1.1.2"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-defect-indication">Defect Indication</xref></t>
                        <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.3.2.1.2.1.2.2.2">
                          <li pn="section-toc.1-1.3.2.1.2.1.2.2.2.1">
                            <t indent="0" pn="section-toc.1-1.3.2.1.2.1.2.2.2.1.1"><xref derivedContent="3.1.1.2.1" format="counter" sectionFormat="of" target="section-3.1.1.2.1"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-forward-defect-indication-f">Forward Defect Indication (FDI)</xref></t>
                          </li>
                          <li pn="section-toc.1-1.3.2.1.2.1.2.2.2.2">
                            <t indent="0" pn="section-toc.1-1.3.2.1.2.1.2.2.2.2.1"><xref derivedContent="3.1.1.2.2" format="counter" sectionFormat="of" target="section-3.1.1.2.2"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-reverse-defect-indication-r">Reverse Defect Indication (RDI)</xref></t>
                          </li>
                        </ul>
                      </li>
                    </ul>
                  </li>
                  <li pn="section-toc.1-1.3.2.1.2.2">
                    <t indent="0" pn="section-toc.1-1.3.2.1.2.2.1"><xref derivedContent="3.1.2" format="counter" sectionFormat="of" target="section-3.1.2"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-on-demand-fault-management-">On-Demand Fault Management Functions</xref></t>
                    <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.3.2.1.2.2.2">
                      <li pn="section-toc.1-1.3.2.1.2.2.2.1">
                        <t indent="0" pn="section-toc.1-1.3.2.1.2.2.2.1.1"><xref derivedContent="3.1.2.1" format="counter" sectionFormat="of" target="section-3.1.2.1"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-connectivity-verification">Connectivity Verification</xref></t>
                      </li>
                      <li pn="section-toc.1-1.3.2.1.2.2.2.2">
                        <t indent="0" pn="section-toc.1-1.3.2.1.2.2.2.2.1"><xref derivedContent="3.1.2.2" format="counter" sectionFormat="of" target="section-3.1.2.2"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-fault-isolation">Fault Isolation</xref></t>
                      </li>
                    </ul>
                  </li>
                </ul>
              </li>
              <li pn="section-toc.1-1.3.2.2">
                <t indent="0" pn="section-toc.1-1.3.2.2.1"><xref derivedContent="3.2" format="counter" sectionFormat="of" target="section-3.2"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-performance-management">Performance Management</xref></t>
                <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.3.2.2.2">
                  <li pn="section-toc.1-1.3.2.2.2.1">
                    <t indent="0" pn="section-toc.1-1.3.2.2.2.1.1"><xref derivedContent="3.2.1" format="counter" sectionFormat="of" target="section-3.2.1"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-packet-loss">Packet Loss</xref></t>
                  </li>
                  <li pn="section-toc.1-1.3.2.2.2.2">
                    <t indent="0" pn="section-toc.1-1.3.2.2.2.2.1"><xref derivedContent="3.2.2" format="counter" sectionFormat="of" target="section-3.2.2"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-packet-delay-and-jitter">Packet Delay and Jitter</xref></t>
                  </li>
                </ul>
              </li>
            </ul>
          </li>
          <li pn="section-toc.1-1.4">
            <t indent="0" pn="section-toc.1-1.4.1"><xref derivedContent="4" format="counter" sectionFormat="of" target="section-4"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-security-considerations">Security Considerations</xref></t>
          </li>
          <li pn="section-toc.1-1.5">
            <t indent="0" pn="section-toc.1-1.5.1"><xref derivedContent="5" format="counter" sectionFormat="of" target="section-5"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-iana-considerations">IANA Considerations</xref></t>
          </li>
          <li pn="section-toc.1-1.6">
            <t indent="0" pn="section-toc.1-1.6.1"><xref derivedContent="6" format="counter" sectionFormat="of" target="section-6"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-references">References</xref></t>
            <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.6.2">
              <li pn="section-toc.1-1.6.2.1">
                <t indent="0" pn="section-toc.1-1.6.2.1.1"><xref derivedContent="6.1" format="counter" sectionFormat="of" target="section-6.1"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-normative-references">Normative References</xref></t>
              </li>
              <li pn="section-toc.1-1.6.2.2">
                <t indent="0" pn="section-toc.1-1.6.2.2.1"><xref derivedContent="6.2" format="counter" sectionFormat="of" target="section-6.2"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-informative-references">Informative References</xref></t>
              </li>
            </ul>
          </li>
          <li pn="section-toc.1-1.7">
            <t indent="0" pn="section-toc.1-1.7.1"><xref derivedContent="" format="none" sectionFormat="of" target="section-appendix.a"/><xref derivedContent="" format="title" sectionFormat="of" target="name-acknowledgements">Acknowledgements</xref></t>
          </li>
          <li pn="section-toc.1-1.8">
            <t indent="0" pn="section-toc.1-1.8.1"><xref derivedContent="" format="none" sectionFormat="of" target="section-appendix.b"/><xref derivedContent="" format="title" sectionFormat="of" target="name-authors-addresses">Authors' Addresses</xref></t>
          </li>
        </ul>
      </section>
    </toc>
  </front>
  <middle>
    <section anchor="sect-1" numbered="true" toc="include" removeInRFC="false" pn="section-1">
      <name slugifiedName="name-introduction">Introduction</name>
      <t indent="0" pn="section-1-1">
   This document specifies the requirements and defines a reference
   framework for Ethernet VPN (EVPN) Operations, Administration, and
   Maintenance (OAM) <xref target="RFC6291" format="default" sectionFormat="of" derivedContent="RFC6291"/>. In this context, we use the term "EVPN OAM" to loosely refer to the OAM functions required for and/or
   applicable to <xref target="RFC7432" format="default" sectionFormat="of" derivedContent="RFC7432"/> and <xref target="RFC7623" format="default" sectionFormat="of" derivedContent="RFC7623"/>.</t>
      <t indent="0" pn="section-1-2">
   EVPN is a Layer 2 VPN (L2VPN) solution for multipoint Ethernet
   services with advanced multihoming capabilities that uses BGP for
   distributing Customer/Client Media Access Control (C-MAC) address reachability information
   over the core MPLS/IP network.</t>
      <t indent="0" pn="section-1-3">
   PBB-EVPN combines Provider Backbone Bridging (PBB) <xref target="IEEE-802.1Q" format="default" sectionFormat="of" derivedContent="IEEE-802.1Q"/> with EVPN in
   order to reduce the number of BGP MAC advertisement routes; provide client
   MAC address mobility using C-MAC <xref target="RFC7623" format="default" sectionFormat="of" derivedContent="RFC7623"/> aggregation and
   Backbone MAC (B-MAC) <xref target="RFC7623" format="default" sectionFormat="of" derivedContent="RFC7623"/> sub-netting; confine the scope of C-MAC
   learning to only active flows; offer per-site policies; and avoid C-MAC
   address flushing on topology changes.</t>
      <t indent="0" pn="section-1-4">
   This document focuses on the fault management and performance
   management aspects of EVPN OAM. It defines the layered OAM model
   encompassing the EVPN service layer, network layer, underlying Packet
   Switched Network (PSN) transport layer, and link layer but focuses on
   the service and network layers.</t>
      <section anchor="sect-1.1" numbered="true" toc="include" removeInRFC="false" pn="section-1.1">
        <name slugifiedName="name-relationship-to-other-oam-w">Relationship to Other OAM Work</name>
        <t indent="0" pn="section-1.1-1">
   This document leverages concepts and draws upon elements defined
   and⁠/⁠or used in the following documents:</t>
        <t indent="0" pn="section-1.1-2">
   <xref target="RFC6136" format="default" sectionFormat="of" derivedContent="RFC6136"/> specifies the requirements and a reference model for OAM as
   it relates to L2VPN services, pseudowires, and associated Packet
   Switched Network (PSN) tunnels. This document focuses on Virtual Private LAN Service (VPLS) and Virtual Private Wire Service (VPWS) solutions and services.</t>
        <t indent="0" pn="section-1.1-3">
   <xref target="RFC8029" format="default" sectionFormat="of" derivedContent="RFC8029"/> defines mechanisms for detecting data plane failures in
   MPLS Label Switched Paths (LSPs), including procedures to check the correct operation of the
   data plane as well as mechanisms to verify the data plane against
   the control plane.</t>
        <t indent="0" pn="section-1.1-4">
   <xref target="IEEE-802.1Q" format="default" sectionFormat="of" derivedContent="IEEE-802.1Q"/> specifies the Ethernet Connectivity Fault Management (CFM)
   protocol, which defines the concepts of Maintenance Domains,
   Maintenance Associations, Maintenance End Points, and Maintenance
   Intermediate Points.</t>
        <t indent="0" pn="section-1.1-5">
   <xref target="Y.1731" format="default" sectionFormat="of" derivedContent="Y.1731"/> extends Connectivity Fault Management in the following
   areas: it defines fault notification and alarm suppression functions
   for Ethernet and specifies mechanisms for Ethernet performance
   management, including loss, delay, jitter, and throughput
   measurement.</t>
      </section>
      <section anchor="sect-1.2" numbered="true" toc="include" removeInRFC="false" pn="section-1.2">
        <name slugifiedName="name-specification-of-requiremen">Specification of Requirements</name>
        <t indent="0" pn="section-1.2-1">
    The key words "<bcp14>MUST</bcp14>", "<bcp14>MUST NOT</bcp14>", "<bcp14>REQUIRED</bcp14>", "<bcp14>SHALL</bcp14>", "<bcp14>SHALL NOT</bcp14>", "<bcp14>SHOULD</bcp14>", "<bcp14>SHOULD NOT</bcp14>", "<bcp14>RECOMMENDED</bcp14>", "<bcp14>NOT RECOMMENDED</bcp14>",
    "<bcp14>MAY</bcp14>", and "<bcp14>OPTIONAL</bcp14>" in this document are to be interpreted as
    described in BCP 14 <xref target="RFC2119" format="default" sectionFormat="of" derivedContent="RFC2119"/> <xref target="RFC8174" format="default" sectionFormat="of" derivedContent="RFC8174"/> 
    when, and only when, they appear in all capitals, as shown here.
        </t>
      </section>
      <section anchor="sect-1.3" numbered="true" toc="include" removeInRFC="false" pn="section-1.3">
        <name slugifiedName="name-terminology">Terminology</name>
        <t indent="0" pn="section-1.3-1">
   This document uses the following terminology, much of which is defined
   in <xref target="RFC6136" format="default" sectionFormat="of" derivedContent="RFC6136"/>:

        </t>
        <dl newline="false" spacing="normal" indent="12" pn="section-1.3-2">
          <dt pn="section-1.3-2.1">CE</dt>
          <dd pn="section-1.3-2.2">Customer Edge device; for example, a host, router, or switch.</dd>
          <dt pn="section-1.3-2.3">CFM</dt>
          <dd pn="section-1.3-2.4">Connectivity Fault Management <xref target="IEEE-802.1Q" format="default" sectionFormat="of" derivedContent="IEEE-802.1Q"/></dd>
          <dt pn="section-1.3-2.5">DF</dt>
          <dd pn="section-1.3-2.6">Designated Forwarder <xref target="RFC7432" format="default" sectionFormat="of" derivedContent="RFC7432"/></dd>
          <dt pn="section-1.3-2.7">Down MEP</dt>
          <dd pn="section-1.3-2.8">A MEP that originates traffic away from and terminates
  	     traffic towards the core of the device in whose port it is logically located.</dd>
          <dt pn="section-1.3-2.9">EVI</dt>
          <dd pn="section-1.3-2.10">An EVPN instance spanning the Provider Edge (PE)
	  devices participating in that EVPN <xref target="RFC7432" format="default" sectionFormat="of" derivedContent="RFC7432"/>.</dd>
          <dt pn="section-1.3-2.11">L2VPN</dt>
          <dd pn="section-1.3-2.12">Layer 2 VPN</dd>
          <dt pn="section-1.3-2.13">LOC</dt>
          <dd pn="section-1.3-2.14">Loss of continuity</dd>
          <dt pn="section-1.3-2.15">MA</dt>
          <dd pn="section-1.3-2.16">Maintenance Association; a set of MEPs belonging
	  to the same Maintenance Domain (MD) established to verify the
	  integrity of a single service instance <xref target="IEEE-802.1Q" format="default" sectionFormat="of" derivedContent="IEEE-802.1Q"/>.</dd>
          <dt pn="section-1.3-2.17">MD</dt>
          <dd pn="section-1.3-2.18">Maintenance Domain; an OAM Domain that represents a
	  region over which OAM frames can operate unobstructed <xref target="IEEE-802.1Q" format="default" sectionFormat="of" derivedContent="IEEE-802.1Q"/>.</dd>
          <dt pn="section-1.3-2.19">MEP</dt>
          <dd pn="section-1.3-2.20">Maintenance End Point; it is responsible for
	  origination and termination of OAM frames for a given MA. A MEP is
	  logically located in a device's port <xref target="IEEE-802.1Q" format="default" sectionFormat="of" derivedContent="IEEE-802.1Q"/>.</dd>
          <dt pn="section-1.3-2.21">MIP</dt>
          <dd pn="section-1.3-2.22"> Maintenance Intermediate Point; it is located between
	  peer MEPs and can process and respond to certain OAM frames but does
	  not initiate them. A MIP is logically located in a device's port
	  <xref target="IEEE-802.1Q" format="default" sectionFormat="of" derivedContent="IEEE-802.1Q"/>.</dd>
          <dt pn="section-1.3-2.23">MP2P</dt>
          <dd pn="section-1.3-2.24">Multipoint to Point</dd>
          <dt pn="section-1.3-2.25">NMS</dt>
          <dd pn="section-1.3-2.26">Network Management Station <xref target="RFC6632" format="default" sectionFormat="of" derivedContent="RFC6632"/></dd>
          <dt pn="section-1.3-2.27">P</dt>
          <dd pn="section-1.3-2.28">Provider network interior (non-edge) node</dd>
          <dt pn="section-1.3-2.29">P2MP</dt>
          <dd pn="section-1.3-2.30">Point to Multipoint</dd>
          <dt pn="section-1.3-2.31">PBB</dt>
          <dd pn="section-1.3-2.32">Provider Backbone Bridge <xref target="RFC7623" format="default" sectionFormat="of" derivedContent="RFC7623"/></dd>
          <dt pn="section-1.3-2.33">PE</dt>
          <dd pn="section-1.3-2.34">Provider Edge network device</dd>
          <dt pn="section-1.3-2.35">Up MEP</dt>
          <dd pn="section-1.3-2.36"> A MEP that originates traffic towards and
	  terminates traffic from the core of the device in whose port it is
	  logically located.</dd>
          <dt pn="section-1.3-2.37">VPN</dt>
          <dd pn="section-1.3-2.38">Virtual Private Network</dd>
        </dl>
      </section>
    </section>
    <section anchor="sect-2" numbered="true" toc="include" removeInRFC="false" pn="section-2">
      <name slugifiedName="name-evpn-oam-framework">EVPN OAM Framework</name>
      <section anchor="sect-2.1" numbered="true" toc="include" removeInRFC="false" pn="section-2.1">
        <name slugifiedName="name-oam-layering">OAM Layering</name>
        <t indent="0" pn="section-2.1-1">
   Multiple layers come into play for implementing an L2VPN service
   using the EVPN family of solutions as listed below. The focus of this
   document is the service and network layers.</t>
        <ul spacing="normal" bare="false" empty="false" indent="3" pn="section-2.1-2">
          <li pn="section-2.1-2.1">The service layer runs end to end between the sites or Ethernet
     segments that are being interconnected by the EVPN solution.</li>
          <li pn="section-2.1-2.2">The network layer extends between the EVPN PE (Provider Edge) nodes
     and is mostly transparent to the P (provider network interior)
     nodes (except where flow entropy comes into play). It leverages
     MPLS for service (i.e., EVI) multiplexing and split-horizon
     functions.</li>
          <li pn="section-2.1-2.3">The transport layer is dictated by the networking technology of the
     PSN. It may be based on either MPLS LSPs or IP.</li>
          <li pn="section-2.1-2.4">The link layer is dependent upon the physical technology used.
     Ethernet is a popular choice for this layer, but other alternatives
     are deployed (e.g., Packet over SONET (POS), Dense Wavelength Division Multiplexing (DWDM), etc.).</li>
        </ul>
        <t indent="0" pn="section-2.1-3">
   This layering extends to the set of OAM protocols that are involved
   in the ongoing maintenance and diagnostics of EVPN networks. <xref target="fig-1" format="default" sectionFormat="of" derivedContent="Figure 1"/>
   below depicts the OAM layering and shows which devices have
   visibility into what OAM layer(s).</t>
        <figure anchor="fig-1" align="left" suppress-title="false" pn="figure-1">
          <name slugifiedName="name-oam-layering-2">OAM Layering</name>
          <artwork name="" type="" align="left" alt="" pn="section-2.1-4.1">
        +---+                               +---+
+--+    |   |    +---+    +---+    +---+    |   |    +--+
|CE|----|PE |----| P |----| P |----| P |----|PE |----|CE|
+--+    |   |    +---+    +---+    +---+    |   |    +--+
        +---+                               +---+

  o-------o----------- Service OAM -----------o-------o

          o----------- Network OAM -----------o

          o--------o--------o--------o--------o  Transport OAM

   o----o   o----o   o----o   o----o   o----o   o----o  Link OAM
</artwork>
        </figure>
        <t indent="0" pn="section-2.1-5">
   Service OAM and Network OAM mechanisms only have visibility to the PE
  nodes but not the P nodes. As
   such, they can be used to deduce whether the fault is in the customer's own network, the local CE-PE segment, the PE-PE segment, or
   the remote CE-PE segment(s). EVPN Transport OAM mechanisms can be
   used for fault isolation between the PEs and P nodes.</t>
        <t indent="0" pn="section-2.1-6">
     
   <xref target="fig-2" format="default" sectionFormat="of" derivedContent="Figure 2"/> below shows an example network where Ethernet domains
   are interconnected via EVPN using MPLS, and it shows the OAM mechanisms
   that are applicable at each layer. The details of the layers are described in
   the sections below.</t>
        <figure anchor="fig-2" align="left" suppress-title="false" pn="figure-2">
          <name slugifiedName="name-evpn-oam-example">EVPN OAM Example</name>
          <artwork name="" type="" align="left" alt="" pn="section-2.1-7.1">
        +---+                               +---+
+--+    |   |    +---+    +---+    +---+    |   |    +--+
|CE|----|PE |----| P |----| P |----| P |----|PE |----|CE|
+--+    |   |    +---+    +---+    +---+    |   |    +--+
        +---+                               +---+

   o----o---------- CFM (Service OAM) ----------o----o

          o-------- EVPN Network OAM ---------o

          o--------o--------o--------o--------o MPLS OAM

   o----o   o----o   o----o   o----o   o----o   o----o 802.3 OAM
                                                       [IEEE-802.3]
</artwork>
        </figure>
      </section>
      <section anchor="sect-2.2" numbered="true" toc="include" removeInRFC="false" pn="section-2.2">
        <name slugifiedName="name-evpn-service-oam">EVPN Service OAM</name>
        <t indent="0" pn="section-2.2-1">
   The EVPN Service OAM protocol depends on what service-layer
   technology is being interconnected by the EVPN solution. In the case of
   <xref target="RFC7432" format="default" sectionFormat="of" derivedContent="RFC7432"/> and <xref target="RFC7623" format="default" sectionFormat="of" derivedContent="RFC7623"/>, the service layer is Ethernet; hence, the
   corresponding Service OAM protocol is Ethernet CFM <xref target="IEEE-802.1Q" format="default" sectionFormat="of" derivedContent="IEEE-802.1Q"/>.</t>
        <t indent="0" pn="section-2.2-2">
   EVPN Service OAM is visible to the CEs and EVPN PEs but not to the P
   nodes. This is because the PEs operate at the Ethernet MAC layer in
   <xref target="RFC7432" format="default" sectionFormat="of" derivedContent="RFC7432"/> and <xref target="RFC7623" format="default" sectionFormat="of" derivedContent="RFC7623"/>, whereas the P nodes do not.</t>
        <t indent="0" pn="section-2.2-3">
   The EVPN PE <bcp14>MUST</bcp14> support MIP functions in the applicable Service OAM
   protocol (for example, Ethernet CFM). The EVPN PE <bcp14>SHOULD</bcp14> support MEP
   functions in the applicable Service OAM protocol. This includes both
   Up and Down MEP functions.</t>
        <t indent="0" pn="section-2.2-4">
   As shown in <xref target="fig-3" format="default" sectionFormat="of" derivedContent="Figure 3"/>, the MIP and MEP functions being referred to are
   logically located within the device's port operating at the customer
   level. (There could be MEPs/MIPs within PE ports facing the provider
   network, but they would not be relevant to EVPN Service OAM as the
   traffic passing through them will be encapsulated/tunneled, so any
   customer-level OAM messages will just be treated as data.)  Down MEP
   functions are away from the core of the device while Up MEP functions
   are towards the core of the device (towards the PE forwarding
   mechanism in the case of a PE). OAM messages between the PE Up MEPs
   shown are a type of EVPN Network OAM, while such messages between the
   CEs or from a PE to its local CE or to the remote CE are Service OAMs.</t>
        <figure anchor="fig-3" align="left" suppress-title="false" pn="figure-3">
          <name slugifiedName="name-cfm-details">CFM Details</name>
          <artwork name="" type="" align="left" alt="" pn="section-2.2-5.1">
 +-------+   +----------------+       +----------------+   +-------+
 |+-----+|   |+--------------+|       |+--------------+|   |+-----+|
 ||  CE ||   ||     PE       ||  ...  ||       PE     ||   || CE  ||
 |+--+--+|   |+---+--------+-+|       |+-+--------+---+|   |+--+--+|
 |   |   |   |    |        |  |       |  |        |    |   |   |   |
 |+--+--+|   |+---+-----+  .  |       |  .  +-----+---+|   |+--+--+|
 || MEP ||   ||   | Up ^|  .  |  ...  |  .  | Up ^|   ||   || MEP ||
 ||DownV||   ||MIP|MEP  |  .  |       |  .  |MEP  |MIP||   ||DownV||
 |+--+--+|   ||   |DownV|  .  |       |  .  |DownV|   ||   |+--+--+|
 |   |   |   |+---+-----+  |  |       |  |  +-----+---+|   |   |   |
 +---|---+   +----|--------|--+       +--|--------|----+   +---|---+
     |            |        |             |        |            |
     +------------+        +---  ...  ---+        +------------+
</artwork>
        </figure>
        <t indent="0" pn="section-2.2-6">
   The EVPN PE <bcp14>MUST</bcp14>, by default, learn the MAC address of locally
   attached CE MEPs by snooping on CFM frames and advertising them to
   remote PEs as a MAC/IP Advertisement route. Some means to limit the
   number of MAC addresses that a PE will learn <bcp14>SHOULD</bcp14> be implemented.</t>
        <t indent="0" pn="section-2.2-7">
   The EVPN PE <bcp14>SHOULD</bcp14> advertise any MEP/MIP local to the PE as a MAC/IP
   Advertisement route. Since these are not subject to mobility, they
   <bcp14>SHOULD</bcp14> be advertised with the static (sticky) bit set (see <xref target="RFC7432" sectionFormat="of" section="15.2" format="default" derivedLink="https://rfc-editor.org/rfc/rfc7432#section-15.2" derivedContent="RFC7432"/>).</t>
      </section>
      <section anchor="sect-2.3" numbered="true" toc="include" removeInRFC="false" pn="section-2.3">
        <name slugifiedName="name-evpn-network-oam">EVPN Network OAM</name>
        <t indent="0" pn="section-2.3-1">
   EVPN Network OAM is visible to the PE nodes only. This OAM layer is
   analogous to Virtual Circuit Connectivity Verification (VCCV) <xref target="RFC5085" format="default" sectionFormat="of" derivedContent="RFC5085"/> in the case of VPLS/VPWS. It provides
   mechanisms to check the correct operation of the data plane as well
   as a mechanism to verify the data plane against the control plane.
   This includes the ability to perform fault detection and diagnostics
   on:</t>
        <ul spacing="normal" bare="false" empty="false" indent="3" pn="section-2.3-2">
          <li pn="section-2.3-2.1">the MP2P tunnels used for the transport of unicast traffic between
     PEs. EVPN allows for three different models of unicast label
     assignment: label per EVI, label per &lt;ESI, Ethernet Tag&gt;, and label
     per MAC address. In all three models, the label is bound to an EVPN
     Unicast Forwarding Equivalence Class (FEC).  EVPN Network OAM <bcp14>MUST</bcp14> provide mechanisms to check the
     operation of the data plane and verify that operation against the
     control plane view.</li>
          <li pn="section-2.3-2.2">the MP2P tunnels used for aliasing unicast traffic destined to a
     multihomed Ethernet segment. The three label assignment models,
     discussed above, apply here as well. In all three models, the label
     is bound to an EVPN Aliasing FEC. EVPN Network OAM <bcp14>MUST</bcp14> provide
     mechanisms to check the operation of the data plane and verify that
     operation against the control plane view.</li>
          <li pn="section-2.3-2.3">the multicast tunnels (either MP2P or P2MP) used for the transport
     of broadcast, unknown unicast, and multicast traffic between PEs. In
     the case of ingress replication, a label is allocated per EVI or
     per &lt;EVI, Ethernet Tag&gt; and is bound to an EVPN Multicast FEC. In
     the case of Label Switched Multicast (LSM) and, more specifically,
     aggregate inclusive trees, again, a label may be allocated per EVI
     or per &lt;EVI, Ethernet Tag&gt; and is bound to the tunnel FEC.</li>
          <li pn="section-2.3-2.4">the correct operation of the Ethernet Segment Identifier (ESI) split-horizon filtering function.
     In EVPN, a label is allocated per multihomed Ethernet segment for
     the purpose of performing the access split-horizon enforcement. The
     label is bound to an EVPN Ethernet segment.</li>
          <li pn="section-2.3-2.5">the correct operation of the Designated Forwarder (DF) <xref target="RFC7432" format="default" sectionFormat="of" derivedContent="RFC7432"/>
     filtering function.  EVPN Network OAM <bcp14>MUST</bcp14> provide mechanisms to
     check the operation of the data plane and verify that operation
     against the control plane view for the DF filtering function.</li>
        </ul>
        <t indent="0" pn="section-2.3-3">
   EVPN Network OAM mechanisms <bcp14>MUST</bcp14> provide in-band monitoring
   capabilities. It is desirable, to the extent practical, for OAM test
   messages to share fate with data messages. Details of how to achieve
   this are beyond the scope of this document.</t>
        <t indent="0" pn="section-2.3-4">
   EVPN Network OAM <bcp14>SHOULD</bcp14> provide both proactive and on-demand
   mechanisms of monitoring the data plane operation and data plane
   conformance to the state of the control plane.</t>
      </section>
      <section anchor="sect-2.4" numbered="true" toc="include" removeInRFC="false" pn="section-2.4">
        <name slugifiedName="name-transport-oam-for-evpn">Transport OAM for EVPN</name>
        <t indent="0" pn="section-2.4-1">
   The Transport OAM protocol depends on the nature of the underlying
   transport technology in the PSN. MPLS OAM mechanisms <xref target="RFC8029" format="default" sectionFormat="of" derivedContent="RFC8029"/>
          <xref target="RFC6425" format="default" sectionFormat="of" derivedContent="RFC6425"/> as well as ICMP <xref target="RFC0792" format="default" sectionFormat="of" derivedContent="RFC0792"/> and ICMPv6 <xref target="RFC4443" format="default" sectionFormat="of" derivedContent="RFC4443"/> are applicable,
   depending on whether the PSN employs MPLS or IP transport,
   respectively.  Furthermore, Bidirectional Forwarding Detection (BFD) mechanisms per <xref target="RFC5880" format="default" sectionFormat="of" derivedContent="RFC5880"/>, <xref target="RFC5881" format="default" sectionFormat="of" derivedContent="RFC5881"/>,
   <xref target="RFC5883" format="default" sectionFormat="of" derivedContent="RFC5883"/>, and <xref target="RFC5884" format="default" sectionFormat="of" derivedContent="RFC5884"/> apply. Also, the BFD mechanisms pertaining to
   MPLS-TP LSPs per <xref target="RFC6428" format="default" sectionFormat="of" derivedContent="RFC6428"/> are applicable.</t>
      </section>
      <section anchor="sect-2.5" numbered="true" toc="include" removeInRFC="false" pn="section-2.5">
        <name slugifiedName="name-link-oam">Link OAM</name>
        <t indent="0" pn="section-2.5-1">
   Link OAM depends on the data-link technology being used between the
   PE and P nodes. For example, if Ethernet links are employed, then
   Ethernet Link OAM (<xref target="IEEE-802.3" format="default" sectionFormat="of" derivedContent="IEEE-802.3"/>, Clause 57) may be used.</t>
      </section>
      <section anchor="sect-2.6" numbered="true" toc="include" removeInRFC="false" pn="section-2.6">
        <name slugifiedName="name-oam-interworking">OAM Interworking</name>
        <t indent="0" pn="section-2.6-1">
   When interworking two networking domains, such as actual Ethernet
   and EVPN to provide an end-to-end emulated service, there is a need
   to identify the failure domain and location, even when a PE supports
   both the Service OAM mechanisms and the EVPN Network OAM mechanisms.
   In addition, scalability constraints may not allow the running of proactive
   monitoring, such as Ethernet Continuity Check Messages (CCMs)
   <xref target="IEEE-802.1Q" format="default" sectionFormat="of" derivedContent="IEEE-802.1Q"/>, at a PE to detect the failure of an EVI across the EVPN
   domain. Thus, the mapping of alarms generated upon failure detection
   in one domain (e.g., actual Ethernet or EVPN network domain) to the
   other domain is needed. There are also cases where a PE may not be
   able to process Service OAM messages received from a remote PE over
   the PSN even when such messages are defined, as in the Ethernet case,
   thereby necessitating support for fault notification message mapping
   between the EVPN Network domain and the Service domain.</t>
        <t indent="0" pn="section-2.6-2">
   OAM interworking is not limited, though, to scenarios involving disparate
   network domains. It is possible to perform OAM interworking across
   different layers in the same network domain. In general, alarms generated
   within an OAM layer, as a result of proactive fault detection mechanisms, may be injected into its    client-layer OAM mechanisms. This allows the
   client-layer OAM to trigger event-driven (i.e., asynchronous) fault
   notifications. For example, alarms generated by the Link OAM mechanisms may
   be injected into the Transport OAM layer, and alarms generated by the
   Transport OAM mechanism may be injected into the Network OAM mechanism, and
   so on.</t>
        <t indent="0" pn="section-2.6-3">
   EVPN OAM <bcp14>MUST</bcp14> support interworking between the Network OAM and
   Service OAM mechanisms. EVPN OAM <bcp14>MAY</bcp14> support interworking among
   other OAM layers.</t>
      </section>
    </section>
    <section anchor="sect-3" numbered="true" toc="include" removeInRFC="false" pn="section-3">
      <name slugifiedName="name-evpn-oam-requirements">EVPN OAM Requirements</name>
      <t indent="0" pn="section-3-1">
   This section discusses the EVPN OAM requirements pertaining to fault
   management and performance management.</t>
      <section anchor="sect-3.1" numbered="true" toc="include" removeInRFC="false" pn="section-3.1">
        <name slugifiedName="name-fault-management-requiremen">Fault Management Requirements</name>
        <section anchor="sect-3.1.1" numbered="true" toc="include" removeInRFC="false" pn="section-3.1.1">
          <name slugifiedName="name-proactive-fault-management-">Proactive Fault Management Functions</name>
          <t indent="0" pn="section-3.1.1-1">
   The network operator configures proactive fault management functions
   to run periodically. Certain actions (for
   example, protection switchover or alarm indication signaling) can be
   associated with specific events, such as entering or clearing fault
   states.</t>
          <section anchor="sect-3.1.1.1" numbered="true" toc="include" removeInRFC="false" pn="section-3.1.1.1">
            <name slugifiedName="name-fault-detection-continuity-">Fault Detection (Continuity Check)</name>
            <t indent="0" pn="section-3.1.1.1-1">
   Proactive fault detection is performed by periodically monitoring the
   reachability between service end points, i.e., MEPs in a given MA,
   through the exchange of CCMs <xref target="IEEE-802.1Q" format="default" sectionFormat="of" derivedContent="IEEE-802.1Q"/>. The
   reachability between any two arbitrary MEPs may be monitored for:</t>
            <ul spacing="normal" bare="false" empty="false" indent="3" pn="section-3.1.1.1-2">
              <li pn="section-3.1.1.1-2.1">in-band, per-flow monitoring. This enables per-flow monitoring
     between MEPs. EVPN Network OAM <bcp14>MUST</bcp14> support fault detection with
     per-user flow granularity. EVPN Service OAM <bcp14>MAY</bcp14> support fault
     detection with per-user flow granularity.</li>
              <li pn="section-3.1.1.1-2.2">a representative path. This enables a liveness check of the nodes
     hosting the MEPs, assuming that the loss of continuity (LOC) to the MEP is
     interpreted as a failure of the hosting node. This, however, does
     not conclusively indicate liveness of the path(s) taken by user
     data traffic. This enables node failure detection but not path
     failure detection through the use of a test flow. EVPN Network OAM
     and Service OAM <bcp14>MUST</bcp14> support fault detection using test flows.</li>
              <li pn="section-3.1.1.1-2.3">all paths. For MPLS/IP networks with ECMP, the monitoring of all unicast
     paths between MEPs (on non-adjacent nodes) may not be possible since the
     per-hop ECMP hashing behavior may yield situations where it is impossible
     for a MEP to pick flow entropy characteristics that result in exercising
     the exhaustive set of ECMP paths. The monitoring of all ECMP paths between
     MEPs (on non-adjacent nodes) is not a requirement for EVPN OAM.</li>
            </ul>
            <t indent="0" pn="section-3.1.1.1-3">
   The fact that MPLS/IP networks do not enforce congruency between
   unicast and multicast paths means that the proactive fault detection
   mechanisms for EVPN networks <bcp14>MUST</bcp14> provide procedures to monitor the
   unicast paths independently of the multicast paths. This applies to
   EVPN Service OAM and Network OAM.</t>
          </section>
          <section anchor="sect-3.1.1.2" numbered="true" toc="include" removeInRFC="false" pn="section-3.1.1.2">
            <name slugifiedName="name-defect-indication">Defect Indication</name>
            <t indent="0" pn="section-3.1.1.2-1">
   Defect indications can be categorized into two types: forward and
   reverse, as described below. EVPN Service OAM <bcp14>MUST</bcp14>
   support at least one of these types of event-driven defect indications
   upon the detection of a connectivity defect.</t>
            <section anchor="sect-3.1.1.2.1" numbered="true" toc="include" removeInRFC="false" pn="section-3.1.1.2.1">
              <name slugifiedName="name-forward-defect-indication-f">Forward Defect Indication (FDI)</name>
              <t indent="0" pn="section-3.1.1.2.1-1">
   FDI is used to signal a failure that is detected by a lower-layer
   OAM mechanism. A server MEP (i.e., an actual or virtual MEP)
   transmits a forward defect indication in a direction away
   from the direction of the failure (refer to <xref target="fig-4" format="default" sectionFormat="of" derivedContent="Figure 4"/> below).</t>
              <figure anchor="fig-4" align="left" suppress-title="false" pn="figure-4">
                <name slugifiedName="name-forward-defect-indication">Forward Defect Indication</name>
                <artwork name="" type="" align="left" alt="" pn="section-3.1.1.2.1-2.1">
                           Failure
                              |
       +-----+      +-----+   V   +-----+      +-----+
       |  A  |------|  B  |--XXX--|  C  |------|  D  |
       +-----+      +-----+       +-----+      +-----+

           &lt;===========|             |============&gt;
             Forward                    Forward
             Defect                     Defect
             Indication                 Indication
</artwork>
              </figure>
              <t indent="0" pn="section-3.1.1.2.1-3">
   Forward defect indication may be used for alarm suppression and/or
   for the purpose of interworking with other layer OAM protocols. Alarm
   suppression is useful when a transport-level or network-level fault translates
   to multiple service- or flow-level faults. In such a scenario, it is
   enough to alert a network management station (NMS) of the single
   transport-level or network-level fault in lieu of flooding that NMS with a
   multitude of Service or Flow granularity alarms. EVPN PEs <bcp14>SHOULD</bcp14>
   support forward defect indication in the Service OAM mechanisms.</t>
            </section>
            <section anchor="sect-3.1.1.2.2" numbered="true" toc="include" removeInRFC="false" pn="section-3.1.1.2.2">
              <name slugifiedName="name-reverse-defect-indication-r">Reverse Defect Indication (RDI)</name>
              <t indent="0" pn="section-3.1.1.2.2-1">
   RDI is used to signal that the advertising MEP has detected a LOC defect. RDI is transmitted in the direction of the
   failure (refer to <xref target="fig-5" format="default" sectionFormat="of" derivedContent="Figure 5"/>).</t>
              <figure anchor="fig-5" align="left" suppress-title="false" pn="figure-5">
                <name slugifiedName="name-reverse-defect-indication">Reverse Defect Indication</name>
                <artwork name="" type="" align="left" alt="" pn="section-3.1.1.2.2-2.1">
                           Failure
                              |
       +-----+      +-----+   V   +-----+      +-----+
       |  A  |------|  B  |--XXX--|  C  |------|  D  |
       +-----+      +-----+       +-----+      +-----+

           |===========&gt;             &lt;============|
             Reverse                    Reverse
             Defect                     Defect
             Indication                 Indication
</artwork>
              </figure>
              <t indent="0" pn="section-3.1.1.2.2-3">
   RDI allows single-sided management, where the network operator can
   examine the state of a single MEP and deduce the overall health of a
   monitored service. EVPN PEs <bcp14>SHOULD</bcp14> support reverse defect indication
   in the Service OAM mechanisms. This includes both the ability to
   signal a LOC defect to a remote MEP as well as the ability to
   recognize RDI from a remote MEP. Note that, in a multipoint MA, RDI
   is not a useful indicator of unidirectional fault.  This is because
   RDI carries no indication of the affected MEP(s) with which the
   sender had detected a LOC defect.</t>
            </section>
          </section>
        </section>
        <section anchor="sect-3.1.2" numbered="true" toc="include" removeInRFC="false" pn="section-3.1.2">
          <name slugifiedName="name-on-demand-fault-management-">On-Demand Fault Management Functions</name>
          <t indent="0" pn="section-3.1.2-1">
   On-demand fault management functions are initiated manually by the
   network operator and continue for a bounded time period. These
   functions enable the operator to run diagnostics to investigate a
   defect condition.</t>
          <section anchor="sect-3.1.2.1" numbered="true" toc="include" removeInRFC="false" pn="section-3.1.2.1">
            <name slugifiedName="name-connectivity-verification">Connectivity Verification</name>
            <t indent="0" pn="section-3.1.2.1-1">
   EVPN Network OAM <bcp14>MUST</bcp14> support on-demand connectivity verification
   mechanisms for unicast and multicast destinations. The connectivity
   verification mechanisms <bcp14>SHOULD</bcp14> provide a means for specifying and
   carrying the following in the messages:</t>
            <ul spacing="normal" bare="false" empty="false" indent="3" pn="section-3.1.2.1-2">
              <li pn="section-3.1.2.1-2.1">variable-length payload/padding to test connectivity problems related to the Maximum Transmission Unit (MTU).</li>
              <li pn="section-3.1.2.1-2.2">test frame formats as defined in <xref target="RFC2544" sectionFormat="of" section="C" format="default" derivedLink="https://rfc-editor.org/rfc/rfc2544#appendix-C" derivedContent="RFC2544"/> to detect
     potential packet corruption.</li>
            </ul>
            <t indent="0" pn="section-3.1.2.1-3">
   EVPN Network OAM <bcp14>MUST</bcp14> support connectivity verification at per-flow
   granularity. This includes both user flows (to test a specific path
   between PEs) as well as test flows (to test a representative path
   between PEs).</t>
            <t indent="0" pn="section-3.1.2.1-4">
   EVPN Service OAM <bcp14>MUST</bcp14> support connectivity verification on test flows
   and <bcp14>MAY</bcp14> support connectivity verification on user flows.</t>
            <t indent="0" pn="section-3.1.2.1-5">
   For multicast connectivity verification, EVPN Network OAM <bcp14>MUST</bcp14>
   support reporting on:</t>
            <ul spacing="normal" bare="false" empty="false" indent="3" pn="section-3.1.2.1-6">
              <li pn="section-3.1.2.1-6.1">the DF filtering status of a specific port(s) or all the ports in a
     given bridge domain.</li>
              <li pn="section-3.1.2.1-6.2">the split-horizon filtering status of a specific port(s) or all the
     ports in a given bridge domain.</li>
            </ul>
          </section>
          <section anchor="sect-3.1.2.2" numbered="true" toc="include" removeInRFC="false" pn="section-3.1.2.2">
            <name slugifiedName="name-fault-isolation">Fault Isolation</name>
            <t indent="0" pn="section-3.1.2.2-1">
   EVPN OAM <bcp14>MUST</bcp14> support an on-demand fault localization function. This
   involves the capability to narrow down the locality of a fault to a
   particular port, link, or node. The characteristic of forward/reverse path
   asymmetry in MPLS/IP makes fault isolation a direction-sensitive
   operation. That is, given two PEs A and B, localization of continuity
   failures between them requires running fault-isolation procedures from PE A
   to PE B as well as from PE B to PE A.</t>
            <t indent="0" pn="section-3.1.2.2-2">
   EVPN Service OAM mechanisms only have visibility to the PEs but not
   the MPLS or IP P nodes. As such, they can be used to deduce whether
   the fault is in the customer's own network, the local CE-PE segment,
   or a remote CE-PE segment(s). EVPN Network and Transport OAM mechanisms
   can be used for fault isolation between the PEs and P nodes.</t>
          </section>
        </section>
      </section>
      <section anchor="sect-3.2" numbered="true" toc="include" removeInRFC="false" pn="section-3.2">
        <name slugifiedName="name-performance-management">Performance Management</name>
        <t indent="0" pn="section-3.2-1">
   Performance management functions can be performed both proactively
   and on demand. Proactive management involves a recurring function,
   where the performance management probes are run continuously without
   a trigger. We cover both proactive and on-demand functions in this
   section.</t>
        <section anchor="sect-3.2.1" numbered="true" toc="include" removeInRFC="false" pn="section-3.2.1">
          <name slugifiedName="name-packet-loss">Packet Loss</name>
          <t indent="0" pn="section-3.2.1-1">
   EVPN Network OAM <bcp14>SHOULD</bcp14> provide mechanisms for measuring packet loss
   for a given service -- for example, <xref target="RFC7680" format="default" sectionFormat="of" derivedContent="RFC7680"/> and <xref target="RFC6673" format="default" sectionFormat="of" derivedContent="RFC6673"/>.</t>
          <t indent="0" pn="section-3.2.1-2">
   Given that EVPN provides inherent support for multipoint-to-multipoint
   connectivity, packet loss cannot be accurately measured by means of
   counting user data packets. This is because user packets can be delivered
   to more PEs or more ports than are necessary (e.g., due to broadcast,
   unpruned multicast, or unknown unicast flooding). As such, a statistical
   means of approximating the packet loss rate is required.  This can be achieved
   by sending "synthetic" OAM packets that are counted only by those ports
   (MEPs) that are required to receive them.  This provides a statistical
   approximation of the number of data frames lost, even with
   multipoint-to-multipoint connectivity.</t>
        </section>
        <section anchor="sect-3.2.2" numbered="true" toc="include" removeInRFC="false" pn="section-3.2.2">
          <name slugifiedName="name-packet-delay-and-jitter">Packet Delay and Jitter</name>
          <t indent="0" pn="section-3.2.2-1">
   EVPN Service OAM <bcp14>SHOULD</bcp14> support measurement of one-way and two-way
   packet delay and delay variation (jitter) across the EVPN network.
   Measurement of one-way delay requires clock synchronization between
   the probe source and target devices. Mechanisms for clock
   synchronization are outside the scope of this document. Note that
   Service OAM performance management mechanisms defined in <xref target="Y.1731" format="default" sectionFormat="of" derivedContent="Y.1731"/> can
   be used. See also <xref target="RFC7679" format="default" sectionFormat="of" derivedContent="RFC7679"/>, <xref target="RFC2681" format="default" sectionFormat="of" derivedContent="RFC2681"/>, and <xref target="RFC3393" format="default" sectionFormat="of" derivedContent="RFC3393"/>.</t>
          <t indent="0" pn="section-3.2.2-2">
   EVPN Network OAM <bcp14>MAY</bcp14> support measurement of one-way and two-way
   packet delay and delay variation (jitter) across the EVPN network.</t>
        </section>
      </section>
    </section>
    <section anchor="sect-4" numbered="true" toc="include" removeInRFC="false" pn="section-4">
      <name slugifiedName="name-security-considerations">Security Considerations</name>
      <t indent="0" pn="section-4-1">
   EVPN OAM <bcp14>MUST</bcp14> prevent OAM packets from leaking outside of the EVPN
   network or outside their corresponding Maintenance Domain. This can
   be done for CFM, for example, by having MEPs implement a filtering
   function based on the Maintenance Level associated with received OAM
   packets.</t>
      <t indent="0" pn="section-4-2">
   EVPN OAM <bcp14>SHOULD</bcp14> provide mechanisms for implementation and optional
   use to:</t>
      <ul spacing="normal" bare="false" empty="false" indent="3" pn="section-4-3">
        <li pn="section-4-3.1">prevent denial-of-service attacks caused by exploitation of the OAM
     message channel (for example, by forging messages to exceed a
     Maintenance End Point's capacity to maintain state).</li>
        <li pn="section-4-3.2">authenticate communicating end points (for example, MEPs and MIPs).</li>
      </ul>
    </section>
    <section anchor="sect-5" numbered="true" toc="include" removeInRFC="false" pn="section-5">
      <name slugifiedName="name-iana-considerations">IANA Considerations</name>
      <t indent="0" pn="section-5-1">
   This document has no IANA actions.</t>
    </section>
  </middle>
  <back>
    <references pn="section-6">
      <name slugifiedName="name-references">References</name>
      <references pn="section-6.1">
        <name slugifiedName="name-normative-references">Normative References</name>
        <reference anchor="RFC0792" target="https://www.rfc-editor.org/info/rfc792" quoteTitle="true" derivedAnchor="RFC0792">
          <front>
            <title>Internet Control Message Protocol</title>
            <author initials="J." surname="Postel" fullname="J. Postel">
              <organization showOnFrontPage="true"/>
            </author>
            <date year="1981" month="September"/>
          </front>
          <seriesInfo name="STD" value="5"/>
          <seriesInfo name="RFC" value="792"/>
          <seriesInfo name="DOI" value="10.17487/RFC0792"/>
        </reference>
        <reference anchor="RFC2119" target="https://www.rfc-editor.org/info/rfc2119" quoteTitle="true" derivedAnchor="RFC2119">
          <front>
            <title>Key words for use in RFCs to Indicate Requirement Levels</title>
            <author initials="S." surname="Bradner" fullname="S. Bradner">
              <organization showOnFrontPage="true"/>
            </author>
            <date year="1997" month="March"/>
            <abstract>
              <t indent="0">In many standards track documents several words are used to signify the requirements in the specification.  These words are often capitalized. This document defines these words as they should be interpreted in IETF documents.  This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.</t>
            </abstract>
          </front>
          <seriesInfo name="BCP" value="14"/>
          <seriesInfo name="RFC" value="2119"/>
          <seriesInfo name="DOI" value="10.17487/RFC2119"/>
        </reference>
        <reference anchor="RFC4443" target="https://www.rfc-editor.org/info/rfc4443" quoteTitle="true" derivedAnchor="RFC4443">
          <front>
            <title>Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification</title>
            <author initials="A." surname="Conta" fullname="A. Conta">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="S." surname="Deering" fullname="S. Deering">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="M." surname="Gupta" fullname="M. Gupta" role="editor">
              <organization showOnFrontPage="true"/>
            </author>
            <date year="2006" month="March"/>
            <abstract>
              <t indent="0">This document describes the format of a set of control messages used in ICMPv6 (Internet Control Message Protocol).  ICMPv6 is the Internet Control Message Protocol for Internet Protocol version 6 (IPv6).  [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="STD" value="89"/>
          <seriesInfo name="RFC" value="4443"/>
          <seriesInfo name="DOI" value="10.17487/RFC4443"/>
        </reference>
        <reference anchor="RFC5880" target="https://www.rfc-editor.org/info/rfc5880" quoteTitle="true" derivedAnchor="RFC5880">
          <front>
            <title>Bidirectional Forwarding Detection (BFD)</title>
            <author initials="D." surname="Katz" fullname="D. Katz">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="D." surname="Ward" fullname="D. Ward">
              <organization showOnFrontPage="true"/>
            </author>
            <date year="2010" month="June"/>
            <abstract>
              <t indent="0">This document describes a protocol intended to detect faults in the bidirectional path between two forwarding engines, including interfaces, data link(s), and to the extent possible the forwarding engines themselves, with potentially very low latency.  It operates independently of media, data protocols, and routing protocols. [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="5880"/>
          <seriesInfo name="DOI" value="10.17487/RFC5880"/>
        </reference>
        <reference anchor="RFC5881" target="https://www.rfc-editor.org/info/rfc5881" quoteTitle="true" derivedAnchor="RFC5881">
          <front>
            <title>Bidirectional Forwarding Detection (BFD) for IPv4 and IPv6 (Single Hop)</title>
            <author initials="D." surname="Katz" fullname="D. Katz">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="D." surname="Ward" fullname="D. Ward">
              <organization showOnFrontPage="true"/>
            </author>
            <date year="2010" month="June"/>
            <abstract>
              <t indent="0">This document describes the use of the Bidirectional Forwarding Detection (BFD) protocol over IPv4 and IPv6 for single IP hops. [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="5881"/>
          <seriesInfo name="DOI" value="10.17487/RFC5881"/>
        </reference>
        <reference anchor="RFC5883" target="https://www.rfc-editor.org/info/rfc5883" quoteTitle="true" derivedAnchor="RFC5883">
          <front>
            <title>Bidirectional Forwarding Detection (BFD) for Multihop Paths</title>
            <author initials="D." surname="Katz" fullname="D. Katz">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="D." surname="Ward" fullname="D. Ward">
              <organization showOnFrontPage="true"/>
            </author>
            <date year="2010" month="June"/>
            <abstract>
              <t indent="0">This document describes the use of the Bidirectional Forwarding Detection (BFD) protocol over multihop paths, including unidirectional links.  [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="5883"/>
          <seriesInfo name="DOI" value="10.17487/RFC5883"/>
        </reference>
        <reference anchor="RFC5884" target="https://www.rfc-editor.org/info/rfc5884" quoteTitle="true" derivedAnchor="RFC5884">
          <front>
            <title>Bidirectional Forwarding Detection (BFD) for MPLS Label Switched Paths (LSPs)</title>
            <author initials="R." surname="Aggarwal" fullname="R. Aggarwal">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="K." surname="Kompella" fullname="K. Kompella">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="T." surname="Nadeau" fullname="T. Nadeau">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="G." surname="Swallow" fullname="G. Swallow">
              <organization showOnFrontPage="true"/>
            </author>
            <date year="2010" month="June"/>
            <abstract>
              <t indent="0">One desirable application of Bidirectional Forwarding Detection (BFD) is to detect a Multiprotocol Label Switching (MPLS) Label Switched Path (LSP) data plane failure.  LSP Ping is an existing mechanism for detecting MPLS data plane failures and for verifying the MPLS LSP data plane against the control plane.  BFD can be used for the former, but not for the latter.  However, the control plane processing required for BFD Control packets is relatively smaller than the processing required for LSP Ping messages.  A combination of LSP Ping and BFD can be used to provide faster data plane failure detection and/or make it possible to provide such detection on a greater number of LSPs.  This document describes the applicability of BFD in relation to LSP Ping for this application.  It also describes procedures for using BFD in this environment.  [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="5884"/>
          <seriesInfo name="DOI" value="10.17487/RFC5884"/>
        </reference>
        <reference anchor="RFC6291" target="https://www.rfc-editor.org/info/rfc6291" quoteTitle="true" derivedAnchor="RFC6291">
          <front>
            <title>Guidelines for the Use of the "OAM" Acronym in the IETF</title>
            <author initials="L." surname="Andersson" fullname="L. Andersson">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="H." surname="van Helvoort" fullname="H. van Helvoort">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="R." surname="Bonica" fullname="R. Bonica">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="D." surname="Romascanu" fullname="D. Romascanu">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="S." surname="Mansfield" fullname="S. Mansfield">
              <organization showOnFrontPage="true"/>
            </author>
            <date year="2011" month="June"/>
            <abstract>
              <t indent="0">At first glance, the acronym "OAM" seems to be well-known and well-understood.  Looking at the acronym a bit more closely reveals a set of recurring problems that are revisited time and again.</t>
              <t indent="0">This document provides a definition of the acronym "OAM" (Operations, Administration, and Maintenance) for use in all future IETF documents that refer to OAM.  There are other definitions and acronyms that will be discussed while exploring the definition of the constituent parts of the "OAM" term.  This memo documents an Internet Best Current  Practice.</t>
            </abstract>
          </front>
          <seriesInfo name="BCP" value="161"/>
          <seriesInfo name="RFC" value="6291"/>
          <seriesInfo name="DOI" value="10.17487/RFC6291"/>
        </reference>
        <reference anchor="RFC6425" target="https://www.rfc-editor.org/info/rfc6425" quoteTitle="true" derivedAnchor="RFC6425">
          <front>
            <title>Detecting Data-Plane Failures in Point-to-Multipoint MPLS - Extensions to LSP Ping</title>
            <author initials="S." surname="Saxena" fullname="S. Saxena" role="editor">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="G." surname="Swallow" fullname="G. Swallow">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="Z." surname="Ali" fullname="Z. Ali">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="A." surname="Farrel" fullname="A. Farrel">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="S." surname="Yasukawa" fullname="S. Yasukawa">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="T." surname="Nadeau" fullname="T. Nadeau">
              <organization showOnFrontPage="true"/>
            </author>
            <date year="2011" month="November"/>
            <abstract>
              <t indent="0">Recent proposals have extended the scope of Multiprotocol Label Switching (MPLS) Label Switched Paths (LSPs) to encompass point-to-multipoint (P2MP) LSPs.</t>
              <t indent="0">The requirement for a simple and efficient mechanism that can be used to detect data-plane failures in point-to-point (P2P) MPLS LSPs has been recognized and has led to the development of techniques for fault detection and isolation commonly referred to as "LSP ping".</t>
              <t indent="0">The scope of this document is fault detection and isolation for P2MP MPLS LSPs.  This documents does not replace any of the mechanisms of LSP ping, but clarifies their applicability to MPLS P2MP LSPs, and extends the techniques and mechanisms of LSP ping to the MPLS P2MP environment.</t>
              <t indent="0">This document updates RFC 4379.  [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="6425"/>
          <seriesInfo name="DOI" value="10.17487/RFC6425"/>
        </reference>
        <reference anchor="RFC6428" target="https://www.rfc-editor.org/info/rfc6428" quoteTitle="true" derivedAnchor="RFC6428">
          <front>
            <title>Proactive Connectivity Verification, Continuity Check, and Remote Defect Indication for the MPLS Transport Profile</title>
            <author initials="D." surname="Allan" fullname="D. Allan" role="editor">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="G." surname="Swallow" fullname="G. Swallow" role="editor">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="J." surname="Drake" fullname="J. Drake" role="editor">
              <organization showOnFrontPage="true"/>
            </author>
            <date year="2011" month="November"/>
            <abstract>
              <t indent="0">Continuity Check, Proactive Connectivity Verification, and Remote Defect Indication functionalities are required for MPLS Transport Profile (MPLS-TP) Operations, Administration, and Maintenance (OAM).</t>
              <t indent="0">Continuity Check monitors a Label Switched Path for any loss of continuity defect.  Connectivity Verification augments Continuity Check in order to provide confirmation that the desired source is connected to the desired sink.  Remote Defect Indication enables an end point to report, to its associated end point, a fault or defect condition that it detects on a pseudowire, Label Switched Path, or Section.</t>
              <t indent="0">This document specifies specific extensions to Bidirectional Forwarding Detection (BFD) and methods for proactive Continuity Check, Continuity Verification, and Remote Defect Indication for MPLS-TP pseudowires, Label Switched Paths, and Sections using BFD as extended by this memo.  [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="6428"/>
          <seriesInfo name="DOI" value="10.17487/RFC6428"/>
        </reference>
        <reference anchor="RFC7432" target="https://www.rfc-editor.org/info/rfc7432" quoteTitle="true" derivedAnchor="RFC7432">
          <front>
            <title>BGP MPLS-Based Ethernet VPN</title>
            <author initials="A." surname="Sajassi" fullname="A. Sajassi" role="editor">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="R." surname="Aggarwal" fullname="R. Aggarwal">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="N." surname="Bitar" fullname="N. Bitar">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="A." surname="Isaac" fullname="A. Isaac">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="J." surname="Uttaro" fullname="J. Uttaro">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="J." surname="Drake" fullname="J. Drake">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="W." surname="Henderickx" fullname="W. Henderickx">
              <organization showOnFrontPage="true"/>
            </author>
            <date year="2015" month="February"/>
            <abstract>
              <t indent="0">This document describes procedures for BGP MPLS-based Ethernet VPNs (EVPN).  The procedures described here meet the requirements specified in RFC 7209 -- "Requirements for Ethernet VPN (EVPN)".</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="7432"/>
          <seriesInfo name="DOI" value="10.17487/RFC7432"/>
        </reference>
        <reference anchor="RFC7623" target="https://www.rfc-editor.org/info/rfc7623" quoteTitle="true" derivedAnchor="RFC7623">
          <front>
            <title>Provider Backbone Bridging Combined with Ethernet VPN (PBB-EVPN)</title>
            <author initials="A." surname="Sajassi" fullname="A. Sajassi" role="editor">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="S." surname="Salam" fullname="S. Salam">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="N." surname="Bitar" fullname="N. Bitar">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="A." surname="Isaac" fullname="A. Isaac">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="W." surname="Henderickx" fullname="W. Henderickx">
              <organization showOnFrontPage="true"/>
            </author>
            <date year="2015" month="September"/>
            <abstract>
              <t indent="0">This document discusses how Ethernet Provider Backbone Bridging (PBB) can be combined with Ethernet VPN (EVPN) in order to reduce the number of BGP MAC Advertisement routes by aggregating Customer/Client MAC (C-MAC) addresses via Provider Backbone MAC (B-MAC) address, provide client MAC address mobility using C-MAC aggregation, confine the scope of C-MAC learning to only active flows, offer per-site policies, and avoid C-MAC address flushing on topology changes.  The combined solution is referred to as PBB-EVPN.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="7623"/>
          <seriesInfo name="DOI" value="10.17487/RFC7623"/>
        </reference>
        <reference anchor="RFC8029" target="https://www.rfc-editor.org/info/rfc8029" quoteTitle="true" derivedAnchor="RFC8029">
          <front>
            <title>Detecting Multiprotocol Label Switched (MPLS) Data-Plane Failures</title>
            <author initials="K." surname="Kompella" fullname="K. Kompella">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="G." surname="Swallow" fullname="G. Swallow">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="C." surname="Pignataro" fullname="C. Pignataro" role="editor">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="N." surname="Kumar" fullname="N. Kumar">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="S." surname="Aldrin" fullname="S. Aldrin">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="M." surname="Chen" fullname="M. Chen">
              <organization showOnFrontPage="true"/>
            </author>
            <date year="2017" month="March"/>
            <abstract>
              <t indent="0">This document describes a simple and efficient mechanism to detect data-plane failures in Multiprotocol Label Switching (MPLS) Label Switched Paths (LSPs).  It defines a probe message called an "MPLS                        echo request" and a response message called an "MPLS echo reply" for returning the result of the probe.  The MPLS echo request is intended to contain sufficient information to check correct operation of the data plane and to verify the data plane against the control plane, thereby localizing faults.</t>
              <t indent="0">This document obsoletes RFCs 4379, 6424, 6829, and 7537, and updates RFC 1122.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="8029"/>
          <seriesInfo name="DOI" value="10.17487/RFC8029"/>
        </reference>
        <reference anchor="RFC8174" target="https://www.rfc-editor.org/info/rfc8174" quoteTitle="true" derivedAnchor="RFC8174">
          <front>
            <title>Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words</title>
            <author initials="B." surname="Leiba" fullname="B. Leiba">
              <organization showOnFrontPage="true"/>
            </author>
            <date year="2017" month="May"/>
            <abstract>
              <t indent="0">RFC 2119 specifies common key words that may be used in protocol  specifications.  This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the  defined special meanings.</t>
            </abstract>
          </front>
          <seriesInfo name="BCP" value="14"/>
          <seriesInfo name="RFC" value="8174"/>
          <seriesInfo name="DOI" value="10.17487/RFC8174"/>
        </reference>
      </references>
      <references pn="section-6.2">
        <name slugifiedName="name-informative-references">Informative References</name>
        <reference anchor="IEEE-802.1Q" quoteTitle="true" target="https://doi.org/10.1109/IEEESTD.2014.6991462" derivedAnchor="IEEE-802.1Q">
          <front>
            <title>IEEE Standard for Local and metropolitan area networks--Bridges and Bridged Networks</title>
            <author>
              <organization showOnFrontPage="true">IEEE</organization>
            </author>
            <date month="December" year="2014"/>
          </front>
          <seriesInfo name="IEEE" value="Std 802.1Q-2014"/>
          <seriesInfo name="DOI" value="10.1109/IEEESTD.2014.6991462"/>
        </reference>
        <reference anchor="IEEE-802.3" quoteTitle="true" target="https://doi.org/10.1109/IEEESTD.2018.8457469" derivedAnchor="IEEE-802.3">
          <front>
            <title>IEEE Standard for Ethernet</title>
            <author>
              <organization showOnFrontPage="true">IEEE</organization>
            </author>
            <date year="2018" month="August"/>
          </front>
          <seriesInfo name="IEEE" value="Std 802.3-2018"/>
          <seriesInfo name="DOI" value="10.1109/IEEESTD.2018.8457469"/>
        </reference>
        <reference anchor="RFC2544" target="https://www.rfc-editor.org/info/rfc2544" quoteTitle="true" derivedAnchor="RFC2544">
          <front>
            <title>Benchmarking Methodology for Network Interconnect Devices</title>
            <author initials="S." surname="Bradner" fullname="S. Bradner">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="J." surname="McQuaid" fullname="J. McQuaid">
              <organization showOnFrontPage="true"/>
            </author>
            <date year="1999" month="March"/>
            <abstract>
              <t indent="0">This document is a republication of RFC 1944 correcting the values for the IP addresses which were assigned to be used as the default addresses for networking test equipment. This memo provides information for the Internet community.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="2544"/>
          <seriesInfo name="DOI" value="10.17487/RFC2544"/>
        </reference>
        <reference anchor="RFC2681" target="https://www.rfc-editor.org/info/rfc2681" quoteTitle="true" derivedAnchor="RFC2681">
          <front>
            <title>A Round-trip Delay Metric for IPPM</title>
            <author initials="G." surname="Almes" fullname="G. Almes">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="S." surname="Kalidindi" fullname="S. Kalidindi">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="M." surname="Zekauskas" fullname="M. Zekauskas">
              <organization showOnFrontPage="true"/>
            </author>
            <date year="1999" month="September"/>
            <abstract>
              <t indent="0">This memo defines a metric for round-trip delay of packets across Internet paths.  [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="2681"/>
          <seriesInfo name="DOI" value="10.17487/RFC2681"/>
        </reference>
        <reference anchor="RFC3393" target="https://www.rfc-editor.org/info/rfc3393" quoteTitle="true" derivedAnchor="RFC3393">
          <front>
            <title>IP Packet Delay Variation Metric for IP Performance Metrics (IPPM)</title>
            <author initials="C." surname="Demichelis" fullname="C. Demichelis">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="P." surname="Chimento" fullname="P. Chimento">
              <organization showOnFrontPage="true"/>
            </author>
            <date year="2002" month="November"/>
          </front>
          <seriesInfo name="RFC" value="3393"/>
          <seriesInfo name="DOI" value="10.17487/RFC3393"/>
        </reference>
        <reference anchor="RFC5085" target="https://www.rfc-editor.org/info/rfc5085" quoteTitle="true" derivedAnchor="RFC5085">
          <front>
            <title>Pseudowire Virtual Circuit Connectivity Verification (VCCV): A Control Channel for Pseudowires</title>
            <author initials="T." surname="Nadeau" fullname="T. Nadeau" role="editor">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="C." surname="Pignataro" fullname="C. Pignataro" role="editor">
              <organization showOnFrontPage="true"/>
            </author>
            <date year="2007" month="December"/>
            <abstract>
              <t indent="0">This document describes Virtual Circuit Connectivity Verification (VCCV), which provides a control channel that is associated with a pseudowire (PW), as well as the corresponding operations and management functions (such as connectivity verification) to be used over that control channel.  VCCV applies to all supported access circuit and transport types currently defined for PWs.  [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="5085"/>
          <seriesInfo name="DOI" value="10.17487/RFC5085"/>
        </reference>
        <reference anchor="RFC6136" target="https://www.rfc-editor.org/info/rfc6136" quoteTitle="true" derivedAnchor="RFC6136">
          <front>
            <title>Layer 2 Virtual Private Network (L2VPN) Operations, Administration, and Maintenance (OAM) Requirements and Framework</title>
            <author initials="A." surname="Sajassi" fullname="A. Sajassi" role="editor">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="D." surname="Mohan" fullname="D. Mohan" role="editor">
              <organization showOnFrontPage="true"/>
            </author>
            <date year="2011" month="March"/>
            <abstract>
              <t indent="0">This document provides framework and requirements for Layer 2 Virtual Private Network (L2VPN) Operations, Administration, and Maintenance (OAM).  The OAM framework is intended to provide OAM layering across L2VPN services, pseudowires (PWs), and Packet Switched Network (PSN) tunnels.  This document is intended to identify OAM requirements for L2VPN services, i.e., Virtual Private LAN Service (VPLS), Virtual Private Wire Service (VPWS), and IP-only LAN Service (IPLS). Furthermore, if L2VPN service OAM requirements impose specific requirements on PW OAM and/or PSN OAM, those specific PW and/or PSN OAM requirements are also identified.  This document is not an Internet Standards Track  specification; it is published for informational purposes.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="6136"/>
          <seriesInfo name="DOI" value="10.17487/RFC6136"/>
        </reference>
        <reference anchor="RFC6632" target="https://www.rfc-editor.org/info/rfc6632" quoteTitle="true" derivedAnchor="RFC6632">
          <front>
            <title>An Overview of the IETF Network Management Standards</title>
            <author initials="M." surname="Ersue" fullname="M. Ersue" role="editor">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="B." surname="Claise" fullname="B. Claise">
              <organization showOnFrontPage="true"/>
            </author>
            <date year="2012" month="June"/>
            <abstract>
              <t indent="0">This document gives an overview of the IETF network management standards and summarizes existing and ongoing development of IETF Standards Track network management protocols and data models.  The document refers to other overview documents, where they exist and classifies the standards for easy orientation.  The purpose of this document is, on the one hand, to help system developers and users to select appropriate standard management protocols and data models to address relevant management needs.  On the other hand, the document can be used as an overview and guideline by other Standard Development Organizations or bodies planning to use IETF management technologies and data models.  This document does not cover Operations, Administration, and Maintenance (OAM) technologies on the data-path, e.g., OAM of tunnels, MPLS Transport Profile (MPLS-TP) OAM, and pseudowire as well as the corresponding management models.  This document is not an Internet Standards Track specification; it is published for informational purposes.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="6632"/>
          <seriesInfo name="DOI" value="10.17487/RFC6632"/>
        </reference>
        <reference anchor="RFC6673" target="https://www.rfc-editor.org/info/rfc6673" quoteTitle="true" derivedAnchor="RFC6673">
          <front>
            <title>Round-Trip Packet Loss Metrics</title>
            <author initials="A." surname="Morton" fullname="A. Morton">
              <organization showOnFrontPage="true"/>
            </author>
            <date year="2012" month="August"/>
            <abstract>
              <t indent="0">Many user applications (and the transport protocols that make them possible) require two-way communications.  To assess this capability, and to achieve test system simplicity, round-trip loss measurements are frequently conducted in practice.  The Two-Way Active Measurement Protocol specified in RFC 5357 establishes a round-trip loss measurement capability for the Internet.  However, there is currently no round-trip packet loss metric specified according to the RFC 2330 framework.</t>
              <t indent="0">This memo adds round-trip loss to the set of IP Performance Metrics (IPPM).  [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="6673"/>
          <seriesInfo name="DOI" value="10.17487/RFC6673"/>
        </reference>
        <reference anchor="RFC7679" target="https://www.rfc-editor.org/info/rfc7679" quoteTitle="true" derivedAnchor="RFC7679">
          <front>
            <title>A One-Way Delay Metric for IP Performance Metrics (IPPM)</title>
            <author initials="G." surname="Almes" fullname="G. Almes">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="S." surname="Kalidindi" fullname="S. Kalidindi">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="M." surname="Zekauskas" fullname="M. Zekauskas">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="A." surname="Morton" fullname="A. Morton" role="editor">
              <organization showOnFrontPage="true"/>
            </author>
            <date year="2016" month="January"/>
            <abstract>
              <t indent="0">This memo defines a metric for one-way delay of packets across Internet paths.  It builds on notions introduced and discussed in the IP Performance Metrics (IPPM) Framework document, RFC 2330; the reader is assumed to be familiar with that document.  This memo makes RFC 2679 obsolete.</t>
            </abstract>
          </front>
          <seriesInfo name="STD" value="81"/>
          <seriesInfo name="RFC" value="7679"/>
          <seriesInfo name="DOI" value="10.17487/RFC7679"/>
        </reference>
        <reference anchor="RFC7680" target="https://www.rfc-editor.org/info/rfc7680" quoteTitle="true" derivedAnchor="RFC7680">
          <front>
            <title>A One-Way Loss Metric for IP Performance Metrics (IPPM)</title>
            <author initials="G." surname="Almes" fullname="G. Almes">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="S." surname="Kalidindi" fullname="S. Kalidindi">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="M." surname="Zekauskas" fullname="M. Zekauskas">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="A." surname="Morton" fullname="A. Morton" role="editor">
              <organization showOnFrontPage="true"/>
            </author>
            <date year="2016" month="January"/>
            <abstract>
              <t indent="0">This memo defines a metric for one-way loss of packets across Internet paths.  It builds on notions introduced and discussed in the IP Performance Metrics (IPPM) Framework document, RFC 2330; the reader is assumed to be familiar with that document.  This memo makes RFC 2680 obsolete.</t>
            </abstract>
          </front>
          <seriesInfo name="STD" value="82"/>
          <seriesInfo name="RFC" value="7680"/>
          <seriesInfo name="DOI" value="10.17487/RFC7680"/>
        </reference>
        <reference anchor="Y.1731" quoteTitle="true" derivedAnchor="Y.1731">
          <front>
            <title>Operation, administration and maintenance (OAM) functions and mechanisms for Ethernet-based networks</title>
            <author>
              <organization showOnFrontPage="true">ITU-T</organization>
            </author>
            <date year="2015" month="August"/>
          </front>
          <seriesInfo name="ITU-T Recommendation" value="G.8013/Y.1731"/>
        </reference>
      </references>
    </references>
    <section anchor="sect-6" numbered="false" toc="include" removeInRFC="false" pn="section-appendix.a">
      <name slugifiedName="name-acknowledgements">Acknowledgements</name>
      <t indent="0" pn="section-appendix.a-1">
   The authors would like to thank the following for their review of
   this work and their valuable comments:
<contact fullname="David Black"/>, <contact fullname="Martin Duke"/>, <contact fullname="Xiao Min"/>, <contact fullname="Gregory Mirsky"/>, <contact fullname="Zaheduzzaman Sarker"/>, <contact fullname="Dave Schinazi"/>, <contact fullname="John Scudder"/>, <contact fullname="Melinda Shore"/>, <contact fullname="Robert Wilton"/>, <contact fullname="Alexander Vainshtein"/>, <contact fullname="Stig Venaas"/>, and <contact fullname="Éric Vyncke"/>.</t>
    </section>
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      <name slugifiedName="name-authors-addresses">Authors' Addresses</name>
      <author initials="S." surname="Salam" fullname="Samer Salam">
        <organization showOnFrontPage="true">Cisco</organization>
        <address>
          <postal>
            <street>The Atrium Building, Floor 3</street>
            <street>Weygand St.</street>
            <city>Beirut</city>
            <region/>
            <code/>
            <country>Lebanon</country>
          </postal>
          <email>ssalam@cisco.com</email>
        </address>
      </author>
      <author initials="A." surname="Sajassi" fullname="Ali Sajassi">
        <organization showOnFrontPage="true">Cisco</organization>
        <address>
          <postal>
            <street>170 West Tasman Drive</street>
            <city>San Jose</city>
            <region>CA</region>
            <code>95134</code>
            <country>United States of America</country>
          </postal>
          <email>sajassi@cisco.com</email>
        </address>
      </author>
      <author initials="S." surname="Aldrin" fullname="Sam Aldrin">
        <organization abbrev="Google" showOnFrontPage="true">Google, Inc.</organization>
        <address>
          <postal>
            <street>1600 Amphitheatre Parkway</street>
            <city>Mountain View</city>
            <region>CA</region>
            <code>94043</code>
            <country>United States of America</country>
          </postal>
          <email>aldrin.ietf@gmail.com</email>
        </address>
      </author>
      <author initials="J." surname="Drake" fullname="John E. Drake">
        <organization abbrev="Juniper" showOnFrontPage="true">Juniper Networks</organization>
        <address>
          <postal>
            <street>1194 N. Mathilda Ave.</street>
            <city>Sunnyvale</city>
            <region>CA</region>
            <code>94089</code>
            <country>United States of America</country>
          </postal>
          <email>jdrake@juniper.net</email>
        </address>
      </author>
      <author initials="D." surname="Eastlake 3rd" fullname="Donald E. Eastlake 3rd">
        <organization abbrev="Futurewei" showOnFrontPage="true">Futurewei Technologies</organization>
        <address>
          <postal>
            <street>2386 Panoramic Circle</street>
            <city>Apopka</city>
            <region>FL</region>
            <code>32703</code>
            <country>United States of America</country>
          </postal>
          <phone>+1-508-333-2270</phone>
          <email>d3e3e3@gmail.com</email>
        </address>
      </author>
    </section>
  </back>
</rfc>
