INTERNET-DRAFT                                               V. Govindan
Intended status: Proposed Standard                          M. Mudigonda
                                                              A. Sajassi
                                                           Cisco Systems
                                                               G. Mirsky
                                                                     ZTE
                                                             D. Eastlake
                                                  Futurewei Technologies
Expires: May 1, 2021                                    November 2, 2020


                   Fault Management for EVPN networks
                      draft-ietf-bess-evpn-bfd-02


Abstract

   This document specifies proactive, in-band network OAM mechanisms to
   detect loss of continuity and miss-connection faults that affect
   unicast and multi-destination paths (used by Broadcast, Unknown
   Unicast, and Multicast traffic) in an Ethernet VPN (EVPN) network.
   The mechanisms specified in the draft are based on the widely adopted
   Bidirectional Forwarding Detection (BFD) protocol.


Status of this Memo

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

   Distribution of this document is unlimited. Comments should be sent
   to the authors or the BESS working group mailing list: bess@ietf.org.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups.  Note that
   other groups may also distribute working documents as Internet-
   Drafts.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/1id-abstracts.html. The list of Internet-Draft
   Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html.








Govindan, et al                                                 [Page 1]


Internet-Draft                                 Fault Management for EVPN


Table of Contents

      1. Introduction............................................3
      1.1 Terminology............................................3

      2. Scope of this Document..................................5
      3. Motivation for Running BFD at the EVPN Network Layer....6
      4. Fault Detection for Unicast Traffic.....................7

      5. Fault Detection for BUM Traffic.........................8
      5.1 Ingress Replication....................................8
      5.2 P2MP Tunnels (Label Switched Multicast)................8

      6. BFD Packet Encapsulation...............................10
      6.1 MPLS Encapsulation....................................10
      6.1.1 MPLS Unicast........................................10
      6.1.2 MPLS Ingress Replication............................11
      6.1.3 MPLS LSM (Label Switched Multicast, P2MP)...........12
      6.2 VXLAN Encapsulation...................................12
      6.2.1 VXLAN Unicast.......................................12
      6.2.2 VXLAN Ingress Replication...........................14
      6.2.3 VXLAN LSM (Label Switched Multicast, P2MP)..........14

      7. Scalability Considerations.............................15

      8. IANA Considerations....................................16
      8.1 Pseudowire Associated Channel Type....................16
      8.2 MAC Address...........................................16

      9. Security Considerations................................17

      Acknowledgements..........................................17

      Normative References......................................18
      Informative References....................................20

      Authors' Addresses........................................21















Govindan, et al                                                 [Page 2]


Internet-Draft                                 Fault Management for EVPN


1. Introduction

   [ietf-bess-evpn-oam-req-frmwk] outlines the OAM requirements of
   Ethernet VPN networks (EVPN [RFC7432]).  This document specifies
   mechanisms for proactive fault detection at the network (overlay)
   layer of EVPN. The mechanisms proposed in the draft use the widely
   adopted Bidirectional Forwarding Detection (BFD [RFC5880]) protocol.

   EVPN fault detection mechanisms need to consider unicast traffic
   separately from Broadcast, Unknown Unicast, and Multicast (BUM)
   traffic since they map to different Forwarding Equivalency Classes
   (FECs) in EVPN. Hence this document proposes different fault
   detection mechanisms to suit each type. For unicast traffic and BUM
   traffic via MP2P tunnels, using BFD [RFC5880], and for BUM traffic
   via a P2MP tunnel, using BFD Multipoint Active Tails [RFC8563]
   [mirsky-mpls-p2mp-bfd].

   Packet loss and packet delay measurement are out of scope for this
   document.



1.1 Terminology

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

   The following acronyms are used in this document.

      BFD - Bidirectional Forwarding Detection [RFC5880]

      BUM - Broadcast, Unknown Unicast, and Multicast

      CC - Continuity Check

      CV - Connectivity Verification

      EVI - EVPN Instance

      EVPN - Ethernet VPN [RFC7432]

      FEC - Forwarding Equivalency Class

      GAL - Generic Associated Channel Label [RFC5586]

      LSM - Label Switched Multicast (P2MP)



Govindan, et al                                                 [Page 3]


Internet-Draft                                 Fault Management for EVPN


      LSP - Label Switched Path

      MP2P - Multi-Point to Point

      OAM - Operations, Administration, and Maintenance

      P2MP - Point to Multi-Point (LSM)

      PE - Provider Edge

      VXLAN - Virtual eXtesible Local Area Network (VXLAN) [RFC7348]









































Govindan, et al                                                 [Page 4]


Internet-Draft                                 Fault Management for EVPN


2. Scope of this Document

   This document specifies BFD based mechanisms for proactive fault
   detection for EVPN both as specified in [RFC7432] and also for EVPN
   using VXLAN encapsulation [ietf-vxlan-bfd]. It covers the following:

      o  Unicast traffic.

      o  BUM traffic using Multi-point-to-Point (MP2P) tunnels (ingress
         replication).

      o  BUM traffic using Point-to-Multipoint (P2MP) tunnels (Label
         Switched Multicast (LSM)).

      o  MPLS and VXLAN encapsulation.

   This document does not discuss BFD mechanisms for:

      o  EVPN variants like PBB-EVPN [RFC7623].  It is intended to
         address this in future versions.

      o  Integrated Routing and Bridging (IRB) solution based on EVPN
         [ietf-bess-evpn-inter-subnet-forwarding].  It is intended to
         address this in future versions.

      o  EVPN using other encapsulations such as NVGRE or MPLS over GRE
         [RFC8365].

      o  BUM traffic using MP2MP tunnels.

   This document specifies procedures for BFD asynchronous mode. BFD
   demand mode is outside the scope of this specification except as it
   is used in [RFC8563]. The use of the Echo function is outside the
   scope of this specification.


















Govindan, et al                                                 [Page 5]


Internet-Draft                                 Fault Management for EVPN


3. Motivation for Running BFD at the EVPN Network Layer

   The choice of running BFD at the network layer of the OAM model for
   EVPN [ietf-bess-evpn-oam-req-frmwk] was made after considering the
   following:

   o  In addition to detecting link failures in the EVPN network, BFD
      sessions at the network layer can be used to monitor the
      successful setup of MP2P and P2MP EVPN tunnels transporting
      Unicast and BUM traffic such as label programming.  The scope of
      reachability detection covers the ingress and the egress EVPN PE
      nodes and the network connecting them.

   o  Monitoring a representative set of path(s) or a particular path
      among multiple paths available between two EVPN PE nodes could be
      done by exercising entropy mechanisms such as entropy labels, when
      they are used, or VXLAN source ports.  However, paths that cannot
      be realized by entropy variations cannot be monitored.  The fault
      monitoring requirements outlined by [ietf-bess-evpn-oam-req-frmwk]
      are addressed by the mechanisms proposed by this draft.

   BFD testing between EVPN PE nodes does not guarantee that the EVPN
   service is functioning. (This can be monitored at the service level,
   that is CE to CE.) For example, an egress EVPN-PE could understand
   EVPN labeling received but could switch data to an incorrect
   interface.  However, BFD testing in the EVPN Network Layer does
   provide additional confidence that data transported using those
   tunnels will reach the expected egress node.  When BFD testing in the
   EVPN overlay fails, that can be used as an indication of a Loss-of-
   Connectivity defect in the EVPN underlay that would cause EVPN
   service failure.





















Govindan, et al                                                 [Page 6]


Internet-Draft                                 Fault Management for EVPN


4. Fault Detection for Unicast Traffic

   The mechanisms specified in BFD for MPLS LSPs [RFC5884] [RFC7726] are
   applied to test the handling of unicast EVPN traffic.  The
   discriminators required for de-multiplexing the BFD sessions are
   advertised through BGP. This is needed for MPLS since the label stack
   does not contain enough information to identify the sender of the
   packet.

   The usage of MPLS entropy labels or various VXLAN source ports takes
   care of the requirement to monitor various paths of the multi-path
   server layer network [RFC6790].  Each unique realizable path between
   the participating PE routers MAY be monitored separately when such
   entropy is used.  At least one path of multi-path connectivity
   between two PE routers MUST be tracked with BFD, but in that case the
   granularity of fault-detection will be coarser.

   To support unicast OAM to a PE node, that PE MUST allocate a BFD
   discriminator to be used for BFD messages to it and MUST advertise
   this discriminator with BGP using the BFD Discriminator Attribute
   [ietf-bess-mvpn-fast-failover] in an EVPN MAC/IP Advertisement Route
   [RFC7432]. If configured to do so, once a PE knows a unicast route
   and discriminator for another PE, it endeavors to bring UP and
   maintain a BFD session to that other PE. Once the BFD session is UP,
   the ends of the BFD session MUST NOT change the local discriminator
   values of the BFD Control packets they generate, unless they first
   bring down the session as specified in [RFC5884].  The session is
   brought down if no route or discriminator is available due to
   withdrawal.























Govindan, et al                                                 [Page 7]


Internet-Draft                                 Fault Management for EVPN


5. Fault Detection for BUM Traffic

   Section 5.1 below discusses fault detection for MP2P tunnels using
   ingress replication and Section 5.2 discusses fault detection for
   P2MP tunnels.



5.1 Ingress Replication

   Ingress replication uses separate MP2P tunnels for transporting BUM
   traffic from the ingress PE (head) to a set of one or more egress PEs
   (tails).  The fault detection mechanism specified by this document
   takes advantage of the fact that the head makes a unique copy for
   each tail.

   Another key aspect to be considered in EVPN is the advertisement of
   the Inclusive Multicast Ethernet Tag Route [RFC7432].  The BUM
   traffic flows from a head node to a particular tail only after the
   head receives the inclusive multicast route. This contains the BUM
   EVPN MPLS label (downstream allocated) corresponding to the MP2P
   tunnel for MPLS encapsulation and contains the IP address of the PE
   originating the inclusive multicast route for use in VXLAN
   encapsulation. It also contains a BFD Discriminator Attribute [ietf-
   bess-mvpn-fast-failover].

   There MAY exist multiple BFD sessions between a head PE and an
   individual tail due to (1) the usage of MPLS entropy labels [RFC6790]
   or VXLAN source ports for an inclusive multicast FEC and (2) due to
   multiple MP2P tunnels indicated by different tail labels or IP
   addresses for MPLS or VXLAN. If configured to do so, once a PE knows
   an inclusive multicast route and discriminator for another PE it
   endeavors to bring UP and maintain a BFD session to that other PE.
   Once a BFD session for an MP2P path is UP, the ends of the BFD
   session MUST NOT change the local discriminator values of the BFD
   Control packets they generate, unless they first bring down the
   session as specified in [RFC5884]. The session is brought down if no
   route or discriminator is available due to withdrawal.



5.2 P2MP Tunnels (Label Switched Multicast)

   Fault detection for BUM traffic distributed using a P2MP tunnel uses
   BFD Multipoint Active Tails in one of the three methods providing
   head notification. Sections 5.2.2 and 5.2.3 of [RFC8563] describe two
   of these scenarios ("Head Notification and Tail Solicitation with
   Multipoint Polling" and "Head Notification with Composite Polling").
   [mirsky-mpls-p2mp-bfd] describes the third ("Head Notification
   without Polling"). All three of these modes assume the existence of


Govindan, et al                                                 [Page 8]


Internet-Draft                                 Fault Management for EVPN


   unicast paths from the tails to the head. In addition, Head
   Notification with Composite Polling assumes a head to tail unicast
   path.

   The BUM traffic flows from a head node to the tails after the head
   receives an inclusive multicast route [RFC7432]. This contains the
   BUM EVPN MPLS label (upstream allocated) corresponding to the P2MP
   tunnel for MPLS encapsulation. It also contains a BFD Discriminator
   Attribute [ietf-bess-mvpn-fast-failover].  The BFD discriminator
   advertised by a tail in the inclusive multicast route MUST be used in
   any reverse unicast traffic so the head can determine which tail is
   responding. If configured to do so, once a PE knows an inclusive
   multicast route, it brings UP and maintains a BFD session to the
   tails.  The session is brought down if no such route is available due
   to their withdrawal.

   For MPLS encapsulation of the head to tails BFD, Label Switched
   Multicast is used. For VXLAN encapsulation, BFD is delivered to the
   tails through underlay multicast using an outer multicast IP address.

































Govindan, et al                                                 [Page 9]


Internet-Draft                                 Fault Management for EVPN


6. BFD Packet Encapsulation

   The sections below describe the MPLS and VXLAN encapsulations of BFD
   for EVPN OAM use.



6.1 MPLS Encapsulation

   This section describes use of the Generic Associated Channel Label
   (GAL) for BFD encapsulation in MPLS based EVPN OAM.



6.1.1 MPLS Unicast

   As shown in Figure 1, the packet initially contains the following
   labels: LSP label (transport), the optional entropy label, the EVPN
   Unicast label, and then the Generic Associated Channel label with the
   G-ACh type set to TBD1.  The G-ACh payload of the packet MUST contain
   the destination L2 header (in overlay space) followed by the IP
   header that encapsulates the BFD packet.  The MAC address of the
   inner packet is used to validate the <EVI, MAC> in the receiving
   node.

      - The destination MAC MUST be the dedicated MAC TBD-A (see Section
        8) or the MAC address of the destination PE.
      - The destination IP address MUST be 127.0.0.1/32 for IPv4
        [RFC1812] or ::1/128 for IPv6 [RFC4291].
      - The destination IP port MUST be 3784 [RFC5881].
      - The source IP port MUST be in the range 49152 through 65535.
      - The discriminator values for BFD are obtained through BGP as
        discussed in Section 4 or are exchanged out-of-band or through
        some other means outside the scope of this document.


















Govindan, et al                                                [Page 10]


Internet-Draft                                 Fault Management for EVPN


       <---------- 4 bytes ---------->
      +-------------------------------+  -----
      |          LSP Label            |      |
      +-------------------------------+      |
      :      entropy label indicator  :      |
      + (optional)                    +  MPLS Label Stack
      :      entropy label            :      |
      +-------------------------------+      |
      |      EVPN Unicast label       |
      +-------------------------------+      |
      | Generic Assoc. Channel Label  |      |
      +-------------------------------+  -----
      |  ACH word, Type TBD1 no TLVs  |
      +-------------------------------+  ---     -------
      |    Destination MAC Address    |    |           |
      +               +---------------+    |           |
      |   TBD-A       |               |    |           |
      +---------------+               +  L2 Header     |
      |       Source MAC Address      |    |           |
      +---------------+---------------+    |           |
      | VLAN Ethertype|     VLAN-ID   |    |           |
      +---------------+---------------+    |           |
      |IP4/6 Ethertype|                    |           |
      +---------------+---------------+  ---           |
      /                               /           G-ACh Payload
      /...      IP4/6 Header       .../                |
      /                               /                |
      +-------------------------------+                |
      |                               |                |
      +           UDP Header          +                |
      |                               |                |
      +-------------------------------+                |
      |                               |                |
      +       BFD Control Packet      +                |
      /                               /                |
      /...                         .../  ---------------

                   Figure 1. MPLS Unicast Encapsulation



6.1.2 MPLS Ingress Replication

   The packet initially contains the following labels: LSP label
   (transport), the optional entropy label, the BUM label, and the split
   horizon label [RFC7432] (where applicable).  The G-ACh type is set to
   TBD1.  The G-ACh payload of the packet is as described in Section
   6.1.1.




Govindan, et al                                                [Page 11]


Internet-Draft                                 Fault Management for EVPN


6.1.3 MPLS LSM (Label Switched Multicast, P2MP)

   The encapsulation is the same as in Section 6.1.2 for ingress
   replication except that the transport label identifies the P2MP
   tunnel, in effect the set of tail PEs, rather than identifying a
   single destination PE at the end of an MP2P tunnel.



6.2 VXLAN Encapsulation

   This section describes the use of the VXLAN [RFC7348] for BFD
   encapsulation in VXLAN based EVPN OAM. This specification conforms to
   [ietf-bfd-vxlan]. [Some or all of this section may be removed as
   being redundant with [ietf-bfd-vxlan].]



6.2.1 VXLAN Unicast

   Figure 2 below shows the unicast VXLAN encapsulation.  The outer and
   inner IP headers have a unicast source IP address of the BFD message
   source and a destination IP address of the BFD message destination

   The destination UDP port MUST be 3784 [RFC5881]. The source port MUST
   be in the range 49152 through 65535. If the BFD source has multiple
   IP addresses, entropy MAY be further obtained by using any of those
   addresses assuming the source is prepared for responses directed to
   the IP address used.

   The Your BFD discriminator is the value distributed for this unicast
   OAM purpose by the destination using BGP as discussed in Section 4 or
   is exchanged out-of-band or through some other means outside the
   scope of this document.


















Govindan, et al                                                [Page 12]


Internet-Draft                                 Fault Management for EVPN


       <---------- 4 bytes ---------->
      +-------------------------------+  ---
      |    Destination MAC Address    |    |
      +               +---------------+    |
      |               |               |    |
      +---------------+               +  L2 Header
      |       Source MAC Address      |    |
      +-------------------------------+    |
      |            VLAN Tag           |    |
      +---------------+---------------+    |
      |IP4/6 Ethertype|                    |
      +---------------+---------------+  ---
      /                               /
      /...      IP4/6 Header       .../
      /                               /
      +-------------------------------+
      |                               |
      +           UDP Header          +
      |                               |
      +-------------------------------+
      |                               |
      +          VXLAN Header         +
      |                               |
      +-------------------------------+  ---
      |    Destination MAC Address    |    |
      +               +---------------+    |
      |               |               |    |
      +---------------+               +  L2 Header
      |       Source MAC Address      |    |
      +---------------+---------------+    |
      | IP4 Ethertype |                    |
      +---------------+---------------+  ---
      /                               /
      /...       IP4 Header        .../
      /                               /
      +-------------------------------+
      |                               |
      +           UDP Header          +
      |                               |
      +---------------+---------------+
      |                               |
      +       BFD Control Packet      +
      |                               |
      /...                         .../

                   Figure 2. VXLAN Unicast Encapsulation






Govindan, et al                                                [Page 13]


Internet-Draft                                 Fault Management for EVPN


6.2.2 VXLAN Ingress Replication

   The BFD packet construction is as given in Section 6.2.1 except as
   follows:
   (1) The destination IP address used by the BFD message source is that
       advertised by the destination PE in its Inclusive Multicast EVPN
       route for the MP2P tunnel in question; and
   (2) The Your BFD discriminator used is the one advertised by the BFD
       destination using BGP as discussed in Section 5.1 for the MP2P
       tunnel in question or is exchanged out-of-band or through some
       other means outside the scope of this document.



6.2.3 VXLAN LSM (Label Switched Multicast, P2MP)

   The VXLAN encapsulation for the head-to-tails BFD packets uses the
   multicast destination IP corresponding to the VXLAN VNI.

   The destination port MUST be 3784. For entropy purposes, the source
   port can vary but MUST be in the range 49152 through 65535 [RFC5881].
   If the head PE has multiple IP addresses, entropy MAY be further
   obtained by using any of those addresses.

   The Your BFD discriminator is the value distributed for this
   multicast OAM purpose by the BFD message using BGP as discussed in
   Section 5.2 or is exchanged out-of-band or through some other means
   outside the scope of this document.
























Govindan, et al                                                [Page 14]


Internet-Draft                                 Fault Management for EVPN


7. Scalability Considerations

   The mechanisms proposed by this draft could affect the packet load on
   the network and its elements especially when supporting
   configurations involving a large number of EVIs.  The option of
   slowing down or speeding up BFD timer values can be used by an
   administrator or a network management entity to maintain the overhead
   incurred due to fault monitoring at an acceptable level.












































Govindan, et al                                                [Page 15]


Internet-Draft                                 Fault Management for EVPN


8. IANA Considerations

   The following IANA Actions are requested.



8.1 Pseudowire Associated Channel Type

   IANA is requested to assign a channel type from the "Pseudowire
   Associated Channel Types" registry in [RFC4385] as follows.

         Value   Description    Reference
         -----   ------------   ------------
         TBD1    BFD-EVPN OAM   [this document]



8.2 MAC Address

   IANA is requested to assign a multicast MAC address under the IANA
   OUI [0x01005E900004 suggested] as follows:

         Address   Usage       Reference
         -------  --------   ---------------
         TBD-A    EVPN OAM   [this document]



























Govindan, et al                                                [Page 16]


Internet-Draft                                 Fault Management for EVPN


9. Security Considerations

   Security considerations discussed in [RFC5880], [RFC5883], and
   [RFC8029] apply.

   MPLS security considerations [RFC5920] apply to BFD Control packets
   encapsulated in a MPLS label stack. When BPD Control packets are
   routed, the authentication considerations discussed in [RFC5883]
   should be followed.

   VXLAN BFD security considerations in [ietf-vxlan-bfd] apply to BFD
   packets encapsulate in VXLAN.



Acknowledgements

   The authors wish to thank the following for their comments and
   suggestions:

      Mach Chen































Govindan, et al                                                [Page 17]


Internet-Draft                                 Fault Management for EVPN


Normative References

   [ietf-bess-evpn-inter-subnet-forwarding] Sajassi, A., Salam, S.,
             Thoria, S., Rekhter, Y., Drake, J., Yong, L., and L.
             Dunbar, "Integrated Routing and Bridging in EVPN",
             draft-ietf-bess-evpn-inter-subnet-forwarding-08, work in
             progress, March 2019.

   [ietf-bess-mvpn-fast-failover] Morin, T., Kebler, R., Mirsky, G.,
             "Multicast VPN fast upstream failover",
             draft-ietf-bess-mvpn-fast-failover-05 (work in progress),
             February 2019.

   [ietf-bfd-vxlan] Pallagatti, S., Paragiri, S., Govindan, V.,
             Mudigonda, M., G. Mirsky, "BFD for VXLAN",
             draft-ietf-bfd-vxlan (work in progress), October 2020.

   [mirsky-mpls-p2mp-bfd] G. Mirsky, S. Mishra, "BFD for Multipoint
             Networks over Point-to-Multi-Point MPLS LSP", draft-mirsky-
             mpls-p2mp-bfd (work in progress), October 2020.

   [RFC1812] Baker, F., Ed., "Requirements for IP Version 4 Routers",
             RFC 1812, DOI 10.17487/RFC1812, June 1995,
             <https://www.rfc-editor.org/info/rfc1812>.

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

   [RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing
             Architecture", RFC 4291, DOI 10.17487/RFC4291, February
             2006, <https://www.rfc-editor.org/info/rfc4291>.

   [RFC4385] Bryant, S., Swallow, G., Martini, L., and D. McPherson,
             "Pseudowire Emulation Edge-to-Edge (PWE3) Control Word for
             Use over an MPLS PSN", RFC 4385, DOI 10.17487/RFC4385,
             February 2006, <http://www.rfc-editor.org/info/rfc4385>.

   [RFC5586] Bocci, M., Ed., Vigoureux, M., Ed., and S. Bryant, Ed.,
             "MPLS Generic Associated Channel", RFC 5586, DOI
             10.17487/RFC5586, June 2009, <https://www.rfc-
             editor.org/info/rfc5586>.

   [RFC5880] Katz, D. and D. Ward, "Bidirectional Forwarding Detection
             (BFD)", RFC 5880, DOI 10.17487/RFC5880, June 2010,
             <http://www.rfc-editor.org/info/rfc5880>.

   [RFC5881] Katz, D. and D. Ward, "Bidirectional Forwarding Detection
             (BFD) for IPv4 and IPv6 (Single Hop)", RFC 5881, DOI


Govindan, et al                                                [Page 18]


Internet-Draft                                 Fault Management for EVPN


             10.17487/RFC5881, June 2010, <https://www.rfc-
             editor.org/info/rfc5881>.

   [RFC5883] Katz, D. and D. Ward, "Bidirectional Forwarding Detection
             (BFD) for Multihop Paths", RFC 5883, DOI 10.17487/RFC5883,
             June 2010, <https://www.rfc-editor.org/info/rfc5883>.

   [RFC5884] Aggarwal, R., Kompella, K., Nadeau, T., and G. Swallow,
             "Bidirectional Forwarding Detection (BFD) for MPLS Label
             Switched Paths (LSPs)", RFC 5884, DOI 10.17487/RFC5884,
             June 2010, <https://www.rfc-editor.org/info/rfc5884>.

   [RFC6790] Kompella, K., Drake, J., Amante, S., Henderickx, W., and L.
             Yong, "The Use of Entropy Labels in MPLS Forwarding", RFC
             6790, DOI 10.17487/RFC6790, November 2012, <http://www.rfc-
             editor.org/info/rfc6790>.

   [RFC7348] Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger,
             L., Sridhar, T., Bursell, M., and C. Wright, "Virtual
             eXtensible Local Area Network (VXLAN): A Framework for
             Overlaying Virtualized Layer 2 Networks over Layer 3
             Networks", RFC 7348, DOI 10.17487/RFC7348, August 2014,
             <https://www.rfc-editor.org/info/rfc7348>.

   [RFC7432] Sajassi, A., Ed., Aggarwal, R., Bitar, N., Isaac, A.,
             Uttaro, J., Drake, J., and W. Henderickx, "BGP MPLS-Based
             Ethernet VPN", RFC 7432, DOI 10.17487/RFC7432, February
             2015, <http://www.rfc-editor.org/info/rfc7432>.

   [RFC7623] Sajassi, A., Ed., Salam, S., Bitar, N., Isaac, A., and W.
             Henderickx, "Provider Backbone Bridging Combined with
             Ethernet VPN (PBB-EVPN)", RFC 7623, DOI 10.17487/RFC7623,
             September 2015, <http://www.rfc-editor.org/info/rfc7623>.

   [RFC7726] Govindan, V., Rajaraman, K., Mirsky, G., Akiya, N., and S.
             Aldrin, "Clarifying Procedures for Establishing BFD
             Sessions for MPLS Label Switched Paths (LSPs)", RFC 7726,
             DOI 10.17487/RFC7726, January 2016, <https://www.rfc-
             editor.org/info/rfc7726>.

   [RFC8029] Kompella, K., Swallow, G., Pignataro, C., Ed., Kumar, N.,
             Aldrin, S., and M. Chen, "Detecting Multiprotocol Label
             Switched (MPLS) Data-Plane Failures", RFC 8029, DOI
             10.17487/RFC8029, March 2017, <https://www.rfc-
             editor.org/info/rfc8029>.

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



Govindan, et al                                                [Page 19]


Internet-Draft                                 Fault Management for EVPN


   [RFC8365] Sajassi, A., Ed., Drake, J., Ed., Bitar, N., Shekhar, R.,
             Uttaro, J., and W. Henderickx, "A Network Virtualization
             Overlay Solution Using Ethernet VPN (EVPN)", RFC 8365, DOI
             10.17487/RFC8365, March 2018, <https://www.rfc-
             editor.org/info/rfc8365>.

   [RFC8563] Katz, D., Ward, D., Pallagatti, S., Ed., and G. Mirsky,
             Ed., "Bidirectional Forwarding Detection (BFD) Multipoint
             Active Tails", RFC 8563, DOI 10.17487/RFC8563, April 2019,
             <https://www.rfc-editor.org/info/rfc8563>.



Informative References

   [ietf-bess-evpn-oam-req-frmwk] Salam, S., Sajassi, A., Aldrin, S., J.
             Drake, and D. Eastlake, "EVPN Operations, Administration
             and Maintenance Requirements and Framework",
             draft-ietf-bess-evpn-oam-req-frmwk-00, work in progress,
             February 2019.

   [RFC5920] Fang, L., Ed., "Security Framework for MPLS and GMPLS
             Networks", RFC 5920, DOI 10.17487/RFC5920, July 2010,
             <https://www.rfc-editor.org/info/rfc5920>.




























Govindan, et al                                                [Page 20]


Internet-Draft                                 Fault Management for EVPN


Authors' Addresses


      Vengada Prasad Govindan
      Cisco Systems

      Email: venggovi@cisco.com


      Mudigonda Mallik
      Cisco Systems

      Email: mmudigon@cisco.com


      Ali Sajassi
      Cisco Systems
      170 West Tasman Drive
      San Jose, CA  95134, USA

      Email: sajassi@cisco.com


      Gregory Mirsky
      ZTE Corp.

      Email: gregimirsky@gmail.com


      Donald Eastlake, 3rd
      Futurewei Technologies
      2386 Panoramic Circle
      Apopka, FL 32703 USA

      Phone: +1-508-333-2270
      Email: d3e3e3@gmail.com
















Govindan, et al                                                [Page 21]


Internet-Draft                                 Fault Management for EVPN


Copyright, Disclaimer, and Additional IPR Provisions

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

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document. Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document. Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.






































Govindan, et al                                                [Page 22]