Skip to main content

Multicast Redundant Ingress Router Failover
draft-ietf-mboned-redundant-ingress-failover-02

The information below is for an old version of the document.
Document Type
This is an older version of an Internet-Draft whose latest revision state is "Active".
Authors Greg Shepherd , Zheng Zhang , Yisong Liu , Ying Cheng , Gyan Mishra
Last updated 2023-01-03
RFC stream Internet Engineering Task Force (IETF)
Formats
Additional resources Mailing list discussion
Stream WG state WG Document
Document shepherd (None)
IESG IESG state I-D Exists
Consensus boilerplate Unknown
Telechat date (None)
Responsible AD (None)
Send notices to (None)
draft-ietf-mboned-redundant-ingress-failover-02
MBONED WG                                                    G. Shepherd
Internet-Draft                                       Cisco Systems, Inc.
Intended status: Informational                             Z. Zhang, Ed.
Expires: 7 July 2023                                     ZTE Corporation
                                                                  Y. Liu
                                                            China Mobile
                                                                Y. Cheng
                                                            China Unicom
                                                               G. Mishra
                                                            Verizon Inc.
                                                          3 January 2023

              Multicast Redundant Ingress Router Failover
            draft-ietf-mboned-redundant-ingress-failover-02

Abstract

   This document discusses multicast redundant ingress router failover
   issues, include global multicast and Service Provider Network MVPN
   use case.  This document analyzes specification of global multicast
   and Multicast VPN Fast Upstream Failover and the Ingress PE Standby
   Modes and the benefits of each mode.

Status of This Memo

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

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

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

   This Internet-Draft will expire on 7 July 2023.

Copyright Notice

   Copyright (c) 2023 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

Shepherd, et al.           Expires 7 July 2023                  [Page 1]
Internet-Draft  Multicast Redundant Ingress Router Failo    January 2023

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

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Multicast Redundant Ingress Router Failover . . . . . . . . .   3
     3.1.  Swichover . . . . . . . . . . . . . . . . . . . . . . . .   4
     3.2.  Failure detection . . . . . . . . . . . . . . . . . . . .   7
   4.  Stand-by Modes  . . . . . . . . . . . . . . . . . . . . . . .   7
     4.1.  Cold Root Standby Mode  . . . . . . . . . . . . . . . . .   8
     4.2.  Warm Root Standby Mode  . . . . . . . . . . . . . . . . .   8
     4.3.  Hot Root Standby Mode . . . . . . . . . . . . . . . . . .   9
     4.4.  Summary . . . . . . . . . . . . . . . . . . . . . . . . .  10
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  11
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  11
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  11
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .  11
     7.2.  Informative References  . . . . . . . . . . . . . . . . .  12
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  13

1.  Introduction

   The multicast redundant ingress router failover is an important issue
   in multicast deployment.  This document tries to do a research on it
   in the multicast domain.  The Multicast Domain is a domain which is
   used to forward multicast flow according to specific multicast
   technologies, such as PIM ([RFC7761]), BIER ([RFC8279]), P2MP TE
   tunnel ([RFC4875]), MLDP ([RFC6388]), etc.  The domain may or may not
   connect the multicast source and receiver directly.

   The ingress router is close to the multicast source.  The ingress
   router may connect the multicast source directly, or there may be
   multiple hops between the ingress router and the multicast source.
   In the multicast domain, the ingress router is the most adjacent
   router to the multicast source.  It's also called the first-hop
   router in PIM, or BFIR in BIER, or Ingress LSR in P2MP TE tunnel or
   MLDP.

Shepherd, et al.           Expires 7 July 2023                  [Page 2]
Internet-Draft  Multicast Redundant Ingress Router Failo    January 2023

   The failover function between the multicast source and the ingress
   router can be achieved by many ways, and it is not included in this
   document.

   The egress router is close to the multicast receiver.  The egress
   router may connect the multicast receiver directly, or there may be
   multiple hops between the egress router and the multicast receiver.
   In the multicast domain, the egress router is the most adjacent
   router to the multicast receiver.  It's also called the last-hop
   router in PIM, or BFER in BIER, or Egress LSR in P2MP TE tunnel or
   MLDP.

   There may be some other function deployed in the multicast domain,
   such as static configuration, or AMT ([RFC7450]), or SR P2MP Policy
   ([I-D.ietf-pim-sr-p2mp-policy]).

   This document doesn't discuss the details of these technologies.
   This document discusses the general redundant ingress router failover
   ways in the multicast domain.

   This document discusses global multicast and Service Provider Network
   MVPN use case with redundant ingress PE nodes Upstream Mulitcast Hop
   (UMH) and failover from primary UMH to Standby UMH in a multicast
   domain.  This document analyzes specification Multicast VPN Fast
   Upstream Failover ([RFC9026]) and the Ingress PE Standby Modes and
   the benefits of each mode.

2.  Terminology

   The following abbreviations are used in this document:

   IR: the ingress router which is the most close to the multicast
   source in the multicast domain.

   ER: the egress router which is the most close to the multicast
   receiver in the multicast domain.

   SIR: The IR that is in charge of sending the multicast flow, or the
   flow from the IR is accepted by the ERs, the IR is called as the
   Selected-IR, that is SIR in abbreviation.

   BIR: The IR that is not in charge of sending the multicast flow, or
   the flow from the IR is not accepted by the ERs, but the IR replaces
   the role of SIR once SIR fails.  The IR is called as the Backup-IR,
   that is BIR in abbreviation.

3.  Multicast Redundant Ingress Router Failover

Shepherd, et al.           Expires 7 July 2023                  [Page 3]
Internet-Draft  Multicast Redundant Ingress Router Failo    January 2023

                                 source
                                  ...
                            +-----+      +-----+
                 +----------+ IR1 +------+ IR2 +---------+
                 |multicast +-----+      +-----+         |
                 |domain            ...                  |
                 |                                       |
                 |          +-----+      +-----+         |
                 |          | Rm  |      | Rn  |         |
                 |          ++---++      +--+--+         |
                 |           |   |          |            |
                 |     +-----+   +---+      +-----+      |
                 |     |             |            |      |
                 |   +-v---+      +--v--+      +--v--+   |
                 +---+ ER1 +------+ ER2 +------+ ER3 +---+
                     +-----+      +-----+      +-----+
                      ...           ...          ...
                    receiver      receiver     receiver
                                 Figure 1

   Usually, a multicast source connects directly, or across multiple
   hops to two IRs to avoid single node failure.  As shown in figure 1,
   there are two IRs close to a multicast source.  The two IRs are UMH
   (Upstream Multicast Hop) candidates for the ERs.

   The two IRs gets multicast flow from the mutlcast source, how to
   forward the multicast flow to ERs is different according to the
   technologies deployed in the multicast domain.  For example, for PIM
   which is used in this domain, two PIM Trees that rooted on the two
   IRs may be built separately.

   The IRs works with the other router, such as the ER, in the multicast
   domain to minimize the multicast flow packet loss during the IR
   swichover.

3.1.  Swichover

   There may be some failures occurs in the domain, such as link
   failure, node failure, if the failed link or node is on the multicast
   flow forwarding path, there may be multicast flow packet loss.

   If there are multiple paths from the IR to the ERs, there is no need
   to switch IR when some nodes or links fail.

Shepherd, et al.           Expires 7 July 2023                  [Page 4]
Internet-Draft  Multicast Redundant Ingress Router Failo    January 2023

   *  When PIM is used in the domain as multicast forwarding protocol,
      the forwarding tree for (S, G) or (*, G) is built in advance.
      When a node or link in the forwarding tree fails, the tree is
      rebuilt partially.

   *  When BIER is used in the domain as multicast forwarding protocol,
      there is no need to rebuilt forwarding tree in case of node or
      link failure, the BIER forwarding recovers along with the IGP
      routing convergence.

   *  When P2MP TE tunnel or MLDP is used in the domain as multicast
      forwarding protocol, the forwarding LSP is built in advance.  When
      a node or link in the LSP fails, the LSP may be rebuilt partially.

   *  When static multicast tree or SR P2MP policy is used in the
      domain, the controller needs to re-compute a new forwarding path
      to bypass the failed node or link.

   In some situations, there are some key nodes or links in the network.
   The multicast path can not be recovered due to the key node or link
   failure.  The IR needs swichover.

Shepherd, et al.           Expires 7 July 2023                  [Page 5]
Internet-Draft  Multicast Redundant Ingress Router Failo    January 2023

                                   source
                                    ...
                            +-----+      +-----+
                 +----------+ IR1 +------+ IR2 +---------+
                 |          +--+--+      +--+--+         |
                 |             |            |            |
                 |          +--+--+      +--+--+         |
                 |          | Rx  |      | Ry  |         |
                 |          +-+-+-+      ++---++         |
                 |            | |         |   |          |
                 |            | +-----------+ |          |
                 |            |           | | |          |
                 |            | +---------+ | |          |
                 |            | |           | |          |
                 |          +-v-v-+      +--v-v+         |
                 |          | Rm  |      | Rn  |         |
                 |          ++---++      +--+--+         |
                 |           |   |          |            |
                 |     +-----+   +---+      +-----+      |
                 |     |             |            |      |
                 |   +-v---+      +--v--+      +--v--+   |
                 +---+ ER1 +------+ ER2 +------+ ER3 +---+
                     +-----+      +-----+      +-----+
                      ...           ...          ...
                    receiver      receiver     receiver
                                 Figure 2

   For example in figure 2, there is only one path in the network
   partially.  The IR1, Rx are key nodes in the domain, when IR1 or Rx
   fails, there is no any other path between the IR1 and the ERs.

   *  When PIM is used in the domain, Rm and Rn may choose Ry as the
      upstream node to send Join message to build a new tree which
      rooted with IR2.

   *  When BIER is used in the domain, IR2 should in charge of the
      forwarding role to forward the flow to the ERs.

   *  When P2MP TE tunnel or MLDP is used in the domain, the LSP started
      from IR2 can be built and replace the used LSP started from IR1
      when the used LSP does not work.

   *  When static multicast tree or SR P2MP policy is used in the
      domain, the controller should let the IR2 to forward multicast
      flow to the ERs.

Shepherd, et al.           Expires 7 July 2023                  [Page 6]
Internet-Draft  Multicast Redundant Ingress Router Failo    January 2023

3.2.  Failure detection

   In order to achieve the successful IR switchover, some methods should
   be used for monitoring the IR node failure or the path failure
   between IR and ERs, and the IR can do the switching once the failure
   occurs.  BFD or PING methods can be used for it.

   BFD [RFC5880] can be used in all the deployments.  Multipoint BFD
   [RFC8562] can also be used for the failure detection between IR and
   ERs.  BFD for MPLS LSPs [RFC5884] can be used in P2MP TE tunnel or
   MLDP deployments.  BIER BFD [I-D.ietf-bier-bfd] can be used in BIER
   deployment.

   IPv4 PING [RFC0792] and IPv6 PING [RFC4443] can also be used in all
   the deployments.  LSP-Ping [RFC8029] can be used for P2MP TE tunnel
   or MLDP deployments.  BIER PING [I-D.ietf-bier-ping] can be used in
   BIER deployment.

   BIR and ER can detect the SIR node and path failure easily by the BFD
   and PING methods.  If the monitoring is between SIR and ER, how to
   trigger the switchover quickly is challenging when BIR needs to start
   forwarding the multicast flow.  If the monitoring is between BIR and
   SIR, the path between BIR and SIR may fail, but the path is not the
   way from SIR to ERs, BIR may trigger the switchover by mistake, in
   this case unnecessary duplicate flow occurs.  In this case, the ER
   must support the selective receiving and can be compatible with the
   IR switchover mistake.  In order to minimize the mistaken switchover,
   the reliability of SIR/BIR detection needs to be enhanced, such as
   using redundant reliable paths for detection, etc.

   Multicast VPN Fast Upstream Failover [RFC9026] defines a mechanism to
   detect the P-Tunnel X-PMSI A-D route status using P2MP BFD [RFC5880]
   with a new advertised BGP attribute called a BFP Discriminator
   optional transitive attribute

   Multicast VPN Fast Upstream Failover [RFC9026] defines a new "Standby
   PE" BGP Community that the downstream PE originates and sends a
   "Standby BGP C-multicast route" with Standby Upstream PE UMH route RT
   import EC that identifies the Standby Upstream PE with NLRI
   constructed using RD of Standby Upstream PE UMH route.

4.  Stand-by Modes

   In case there are more than one IRs can be the UMH, and there is no
   other path from an IR to ERs in case of the IR fails, the IR needs to
   be switched.

Shepherd, et al.           Expires 7 July 2023                  [Page 7]
Internet-Draft  Multicast Redundant Ingress Router Failo    January 2023

   Usually there are three types of stand-by modes in multicast IR
   protection.  [RFC9026] has some description on it.  This document
   discusses the detail of the three modes here.

   The ER may send request to upstream router or IR when it finds the
   node or path failure.  The request from the ER may be the PIM tree
   building, or BIER overlay protocol signaling, or LSP building, or
   some other ways to let IR knows whether forwards the multicast flow.

4.1.  Cold Root Standby Mode

   In Cold Root Standby mode, the ER selects an SIR, for example IR1 in
   figure 1, as the SIR and signals to it to get the multicast flow.

   When the ER finds that the SIR is down, or the ER finds that it
   cannot receive flow from IR1, the ER signals to IR2 to get the
   multicast flow.

   *  For IR, the IRs, include SIR and BIR, just do the regular
      operation of forwarding flow according to the request from the ER.

   *  For ER, the ER must select an IR as the SIR and signal to it.
      When the SIR fails or the path between the SIR and ER fails, the
      ER must signal to the BIR to get the flow.

   *  For the intermediate routers, they know nothing about the role of
      IR, they just do the packet forwarding.  There is no duplicate
      packets in the domain.

   In case of the IR switchover, the ER detects the failure of SIR, and
   signals to the BIR.  There is packet loss during the signaling until
   the ER receives the flow from the BIR.

4.2.  Warm Root Standby Mode

   In Warm Root Standby Mode, the ER signals to both IR1 and IR2.

   In case IR1 is the SIR, IR1 forwards the flow to the ER.  The BIR,
   for example the IR2, must not forward the flow to the ER until the
   SIR is down.

   *  For IR, the IR should take the role of SIR or BIR.  The BIR must
      not forward flow to the ER.  When the SIR fails or the path
      between SIR and ER fails, the BIR must start forwarding the flow
      to ER.  But it's hard to know the failure for BIR itself, some
      methods should be taken to let the BIR to get the failure
      notification.

Shepherd, et al.           Expires 7 July 2023                  [Page 8]
Internet-Draft  Multicast Redundant Ingress Router Failo    January 2023

   *  For ER, the ER does not select the SIR or BIR.  The ER just signal
      to both of them.

   *  For the intermediate routers, they know nothing about the role of
      IR, they just do the packet forwarding.  There is no duplicate
      packets in the domain.

   In case of the IR switchover, the BIR detects the failure of the SIR
   and switch to SIR.  There is packet loss during the IR switchover.

   In some deployments, the SIR and BIR may in charge of different
   multicast flow.  For a specific multicast flow, the SIR may be IR1,
   for another multicast flow, the SIR may be IR2.  So the two IRs can
   share the multicast forwarding load.  And another possible deployment
   is, the two IRs can in charge of different ERs for one multicast
   flow.  For example, IR1 sends the multicast flow to some of the ERs,
   and IR2 send the multicast flow to the other ERs.  In case IR1
   detects there is something wrong between IR1 and the ERs, IR1 may
   notify IR2 to take over the responsibility of forwarding the
   multicast flow to these ERs that receive flow from IR1 before.

4.3.  Hot Root Standby Mode

   In Hot Root Standby Mode, the ER signals to both IRs.

   Both IRs are sending the flow to the ER.  The ER must discard the
   duplicate flow from one of the IRs.

   In this situation, there are no SIR or BIR.  Only ER knows which IR
   is the SIR.

   *  For IR, the IR need not to know the roles of SIR or BIR, IR just
      forwarding the flow according to the request received from ER.

   *  For ER, the ER signal to both of the IRs to get the flow.  And the
      ER must discard the duplicated flow from the backup BIR.  When the
      SIR fails or the path between SIR and ER fails, the ER must switch
      the forwarding plane to forward the flow packet comes from the
      BIR.  To be noted, the ERs may choose different SIR or BIR.

   *  For the intermediate routers, they know nothing about the role of
      IR, they just do the packet forwarding.  There are duplicate
      packets forwarded in the domain.

   In case of the IR switchover, the ER detects the failure of the SIR.
   Because there are duplicate flow packets arrive on the ER, the ER
   just switch to forward the flow comes from the BIR.  There may be
   packet loss during the switching.

Shepherd, et al.           Expires 7 July 2023                  [Page 9]
Internet-Draft  Multicast Redundant Ingress Router Failo    January 2023

4.4.  Summary

   The table is a brief comparison among the three modes.  The 'SIR
   failover' means the SIR fails or the path between SIR and ER fails.

   +==============+================+================+=================+
   | role         | Cold Mode      | Warm Mode      | Hot Mode        |
   +==============+================+================+=================+
   | IR           | Forwarding     | Takes the role | Need not to     |
   |              | flow according | of SIR or BIR, | know the roles  |
   |              | to the request | BIR must not   | of SIR or BIR,  |
   |              | from ER.       | forward flow   | just forwarding |
   |              |                | to ER until    | flow according  |
   |              |                | SIR failovers. | to the request  |
   |              |                |                | from ER.        |
   +--------------+----------------+----------------+-----------------+
   | ER           | Must select an | Does not       | Signal to both  |
   |              | IR as SIR to   | select the SIR | of SIR and BIR. |
   |              | signal the     | or BIR, just   | Discards the    |
   |              | request,       | signal to both | duplicate flow  |
   |              | signal to the  | of them.       | from BIR until  |
   |              | BIR to request |                | SIR failover.   |
   |              | the flow when  |                |                 |
   |              | SIR failovers. |                |                 |
   +--------------+----------------+----------------+-----------------+
   | Intermediate | Knows nothing  | Knows nothing  | Knows nothing   |
   | Router       | about SIR or   | about SIR or   | about SIR or    |
   |              | BIR.  No       | BIR.  No       | BIR.            |
   |              | duplicated     | duplicated     | Duplicated flow |
   |              | flow is        | flow is        | is forwarded.   |
   |              | forwarded.     | forwarded.     |                 |
   +--------------+----------------+----------------+-----------------+

                                 Table 1

   The Cold root stand-by mode is the easiest way to implementated, but
   it takes the longest converge time.

   The Hot root stand-by mode takes the most less packet loss, but there
   is duplicated packet forwarding in the domain, more bandwidth is
   occupied.

   The Warm root stand-by mode takes the middle packet loss and converge
   time, but it's hard for BIR to know the failure between SIR and ERs.

Shepherd, et al.           Expires 7 July 2023                 [Page 10]
Internet-Draft  Multicast Redundant Ingress Router Failo    January 2023

   The Hot root stand-by mode described in [RFC9026] Section 5 is the
   best UMH protection mechanism.  There can be duplicated packets
   forwarded in the domain which are dropped per [RFC9026] Section 6 and
   [RFC6513] Section 9.1.  Hot root stand-by mode is the best
   recommended method for MVPN Fast Failover optimization.

   For the network administrator, the most suitable stand-by mode should
   be selected according to the network deployment.

5.  IANA Considerations

   This document does not have any requests for IANA allocation.

6.  Security Considerations

   This document adds no new security considerations.

7.  References

7.1.  Normative References

   [RFC4875]  Aggarwal, R., Ed., Papadimitriou, D., Ed., Yasukawa, S.,
              Ed., and RFC Publisher, "Extensions to Resource
              Reservation Protocol - Traffic Engineering (RSVP-TE) for
              Point-to-Multipoint TE Label Switched Paths (LSPs)",
              RFC 4875, DOI 10.17487/RFC4875, May 2007,
              <https://www.rfc-editor.org/info/rfc4875>.

   [RFC6388]  Wijnands, IJ., Ed., Minei, I., Ed., Kompella, K., Thomas,
              B., and RFC Publisher, "Label Distribution Protocol
              Extensions for Point-to-Multipoint and Multipoint-to-
              Multipoint Label Switched Paths", RFC 6388,
              DOI 10.17487/RFC6388, November 2011,
              <https://www.rfc-editor.org/info/rfc6388>.

   [RFC7450]  Bumgardner, G. and RFC Publisher, "Automatic Multicast
              Tunneling", RFC 7450, DOI 10.17487/RFC7450, February 2015,
              <https://www.rfc-editor.org/info/rfc7450>.

   [RFC7761]  Fenner, B., Handley, M., Holbrook, H., Kouvelas, I.,
              Parekh, R., Zhang, Z., Zheng, L., and RFC Publisher,
              "Protocol Independent Multicast - Sparse Mode (PIM-SM):
              Protocol Specification (Revised)", STD 83, RFC 7761,
              DOI 10.17487/RFC7761, March 2016,
              <https://www.rfc-editor.org/info/rfc7761>.

Shepherd, et al.           Expires 7 July 2023                 [Page 11]
Internet-Draft  Multicast Redundant Ingress Router Failo    January 2023

   [RFC8279]  Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A.,
              Przygienda, T., Aldrin, S., and RFC Publisher, "Multicast
              Using Bit Index Explicit Replication (BIER)", RFC 8279,
              DOI 10.17487/RFC8279, November 2017,
              <https://www.rfc-editor.org/info/rfc8279>.

7.2.  Informative References

   [I-D.ietf-bier-bfd]
              Xiong, Q., Mirsky, G., hu, F., and C. Liu, "BIER BFD",
              Work in Progress, Internet-Draft, draft-ietf-bier-bfd-02,
              5 May 2022, <https://www.ietf.org/archive/id/draft-ietf-
              bier-bfd-02.txt>.

   [I-D.ietf-bier-ping]
              Nainar, N. K., Pignataro, C., Akiya, N., Zheng, L., Chen,
              M., and G. Mirsky, "BIER Ping and Trace", Work in
              Progress, Internet-Draft, draft-ietf-bier-ping-07, 11 May
              2020, <https://www.ietf.org/archive/id/draft-ietf-bier-
              ping-07.txt>.

   [I-D.ietf-pim-sr-p2mp-policy]
              Voyer, D., Filsfils, C., Parekh, R., Bidgoli, H., and Z.
              J. Zhang, "Segment Routing Point-to-Multipoint Policy",
              Work in Progress, Internet-Draft, draft-ietf-pim-sr-p2mp-
              policy-05, 2 July 2022, <https://www.ietf.org/archive/id/
              draft-ietf-pim-sr-p2mp-policy-05.txt>.

   [RFC0792]  Postel, J. and RFC Publisher, "Internet Control Message
              Protocol", STD 5, RFC 792, DOI 10.17487/RFC0792, September
              1981, <https://www.rfc-editor.org/info/rfc792>.

   [RFC4443]  Conta, A., Deering, S., Gupta, M., Ed., and RFC Publisher,
              "Internet Control Message Protocol (ICMPv6) for the
              Internet Protocol Version 6 (IPv6) Specification", STD 89,
              RFC 4443, DOI 10.17487/RFC4443, March 2006,
              <https://www.rfc-editor.org/info/rfc4443>.

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

   [RFC5884]  Aggarwal, R., Kompella, K., Nadeau, T., Swallow, G., and
              RFC Publisher, "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>.

Shepherd, et al.           Expires 7 July 2023                 [Page 12]
Internet-Draft  Multicast Redundant Ingress Router Failo    January 2023

   [RFC6513]  Rosen, E., Ed., Aggarwal, R., Ed., and RFC Publisher,
              "Multicast in MPLS/BGP IP VPNs", RFC 6513,
              DOI 10.17487/RFC6513, February 2012,
              <https://www.rfc-editor.org/info/rfc6513>.

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

   [RFC8562]  Katz, D., Ward, D., Pallagatti, S., Ed., Mirsky, G., Ed.,
              and RFC Publisher, "Bidirectional Forwarding Detection
              (BFD) for Multipoint Networks", RFC 8562,
              DOI 10.17487/RFC8562, April 2019,
              <https://www.rfc-editor.org/info/rfc8562>.

   [RFC9026]  Morin, T., Ed., Kebler, R., Ed., Mirsky, G., Ed., and RFC
              Publisher, "Multicast VPN Fast Upstream Failover",
              RFC 9026, DOI 10.17487/RFC9026, April 2021,
              <https://www.rfc-editor.org/info/rfc9026>.

Authors' Addresses

   Greg Shepherd
   Cisco Systems, Inc.
   170 W. Tasman Dr.
   San Jose,
   United States of America
   Email: gjshep@gmail.com

   Zheng Zhang (editor)
   ZTE Corporation
   Nanjing
   China
   Email: zhang.zheng@zte.com.cn

   Yisong Liu
   China Mobile
   Beijing
   Email: liuyisong@chinamobile.com

Shepherd, et al.           Expires 7 July 2023                 [Page 13]
Internet-Draft  Multicast Redundant Ingress Router Failo    January 2023

   Ying Cheng
   China Unicom
   Beijing
   China
   Email: chengying10@chinaunicom.cn

   Gyan Mishra
   Verizon Inc.
   Email: gyan.s.mishra@verizon.com

Shepherd, et al.           Expires 7 July 2023                 [Page 14]