IGP Multicast Architecture
draft-yong-pim-igp-multicast-arch-01

Versions: 00 01                                                         
Network Working Group                                            L. Yong
Internet-Draft                                                  D. Cheng
Intended status: Standards Track                                  W. Hao
Expires: September 10, 2015                                  D. Eastlake
                                                Huawei Technologies Ltd.
                                                                   A. Qu
                                                                MediaTek
                                                               J. Hudson
                                                                 Brocade
                                                             U. Chunduri
                                                           Ericsson Inc.
                                                           March 9, 2015


                       IGP Multicast Architecture
                  draft-yong-pim-igp-multicast-arch-01

Abstract

   This document specifies the architecture of IP multicast routing
   using an Interior Gateway Protocol (IGP).

Requirements Language

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

Status of This Memo

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

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

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

   This Internet-Draft will expire on September 10, 2015.







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Copyright Notice

   Copyright (c) 2015 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
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   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Overview  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.2.  Motivation  . . . . . . . . . . . . . . . . . . . . . . .   3
     1.3.  Conventions used in this Document . . . . . . . . . . . .   4
     1.4.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   4
   2.  An Overview of IGP  . . . . . . . . . . . . . . . . . . . . .   5
   3.  Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . .   6
   4.  Routing IP Multicast Packets  . . . . . . . . . . . . . . . .   6
     4.1.  Multicast Distribution Tree . . . . . . . . . . . . . . .   7
       4.1.1.  Bidirectional Distribution Tree . . . . . . . . . . .   8
     4.2.  Advertising Multicast Group Membership  . . . . . . . . .   9
     4.3.  Requirements of Edge Routers  . . . . . . . . . . . . . .   9
     4.4.  Intra-Area Multicast Routing  . . . . . . . . . . . . . .  10
     4.5.  Inter-Area Multicast Routing  . . . . . . . . . . . . . .  10
       4.5.1.  Behavior of IS-IS Level 2 Router  . . . . . . . . . .  11
       4.5.2.  Behavior of OSPF ABR  . . . . . . . . . . . . . . . .  11
     4.6.  Heterogeneous Environment . . . . . . . . . . . . . . . .  11
     4.7.  TE (Traffic Engineering) Support  . . . . . . . . . . . .  12
     4.8.  Applications to Overlay Model . . . . . . . . . . . . . .  12
     4.9.  IPv6 and IPv4 . . . . . . . . . . . . . . . . . . . . . .  12
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  12
   6.  Acknowledgement . . . . . . . . . . . . . . . . . . . . . . .  13
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  13
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .  13
     7.2.  Informative References  . . . . . . . . . . . . . . . . .  13
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  14








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1.  Introduction

1.1.  Overview

   In an IP network, an IGP is used to route and forward IP unicast
   packets.  In doing so, the routers collect and maintain the network
   information and store it in their database.  The network information
   includes the identity of the routers and their interconnections.  In
   a traffic engineering enabled network, the information also includes
   traffic related parameters such as link bandwidth.  The network
   information that is already maintained on routers, along with some
   minor IGP protocol extensions as proposed in this document, are
   sufficient to also route IP multicast packets.  This means a single
   IGP can be used for routing both unicast packets and multicast
   packets.  This document describes the architecture of routing IP
   multicast packets using the network information that is disseminated
   by an IGP.

1.2.  Motivation

   With the explosion of IP technology based applications, the support
   of IP multicast delivery over the same IP network that carries IP
   unicast traffic becomes mandatory.  In many aspects, some basic
   requirements for routing IP multicast packets are the same as those
   for routing IP unicast packets; e.g., the "plug and play" nature of
   bringing up the routing engine and enabling the packets forwarding.
   It is desirable to use an IGP that requires minimum configuration and
   currently only routes and forwards IP unicast packets, to also route
   and forward IP multicast packets.

   Current practice in an IP network is to use a separate protocol, such
   as Protocol Independent Multicast (PIM - [RFC4601]), to route and
   forward IP multicast packets, whereby some network information are
   actually retrieved from IGP.  Using a single protocol, i.e., an IGP,
   to route both IP unicast and multicast packets is more efficient;
   this eliminates additional convergence time that would otherwise be
   introduced by the second protocol.  Using one protocol also reduces
   operational complexity.

   In an advanced data center network, the decoupling of network IP
   space from service IP space, for example a VxLAN based network
   overlay [RFC7348], is required.  To support all service applications,
   such an IP network fabric must support both unicast and multicast.
   Decoupling network IP space from service IP address space also
   provides network agility and programmability.  If network IP space is
   decoupled from service IP space, the network itself no longer needs
   manual configuration; an IP network fabric can be formed
   automatically.



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1.3.  Conventions used in this Document

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

1.4.  Terminology

   This document makes use of the following terms:

   o  Edge Router: A router that has direct interfaces with one or more
      IP hosts.

   o  Distribution Tree: a rooted distribution tree with one root and
      one or more leaves that facilitate routing multicast packets.

   o  IGP: Interior Gateway Protocol.

   o  Intra-Area: Refers to the communication between IGP routing nodes
      within a single IGP's area.

   o  Inter-Area: Refer to the communication between IGP routing nodes
      across an area boundary.

   o  IP Multicast Group

   o  Link State Database: The database constructed and maintained by a
      router running link state based routing algorithm such as IS-IS
      and OSPF.  It contains network based information including
      identity of routers and their interconnections, reachable IP
      addresses, etc.

   o  Local Group Database: The database constructed and maintained by
      an edge router that stores and maintains entries of { multicast-
      address, host } pairs for hosts interested in traffic for a multi-
      cast address.

   o  Pruned Tree: A subset of IGP's topology graph with a tree root,
      using which multicast packets are forwarded to one or more
      destination nodes with optimization of the usage of links and
      nodes.

   o  Root Node: A router serving as the root of a multicast
      distribution tree.

   o  TE (Traffic Engineering) Database: The database constructed and
      maintained by a router running a link state based routing
      algorithm with TE extensions such as ISIS-TE and OSPF-TE.  It



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      contains TE parameters (such as bandwidth) that are associated
      with links and nodes.

   o  Transit Router: A router that is capable of receiving an IP
      multicast packet, then replicates it and sends to one or more
      other routers in the same multicast distribution tree.

2.  An Overview of IGP

   There are currently two heavily deployed IGPs, IS-IS
   [RFC1195]/[RFC5308] and OSPF [RFC2328]/[RFC2740].  IS-IS and OSPF are
   different in many aspects, but they both use a link-state algorithm
   and the network information they disseminate for the same IP network
   is the same, including routers' IP addresses, routers'
   interconnections, reachable IP addresses, the network topology, etc.

   An IGP operation can have a hierarchy of two levels.  An IGP runs
   within an area, where each participating router originates and
   advertises its own information (router's identity, interface IP
   addresses, identity of directly connected neighbors, etc.), and this
   information is flooded to all participating routers the entire area
   but not beyond.  As a result, within an IGP area, each participating
   router maintains the information of all routers and their
   interconnections.  This collection of network information is the Link
   State Database, which is currently used as a base to calculate IP
   routing table for unicast packets within an IGP area.  Sometimes we
   refer to the topology within an IGP area as a topology graph.
   Separate IGP areas may be interconnected and, between areas, only
   reachability information is advertised across area boundaries by
   Level-2 routers in IS-IS or Area Border Routers (ABR) in OSPF.

   [RFC1195] specifies an IGP for routing IPv4 unicast packets using IS-
   IS protocol (ISO), whereas [RFC5308] specifies the extensions to
   support routing IPv6 unicast packets.

   OSPFv2 [RFC2328] is an IGP for routing IPv4 unicast packets whereas
   OSPFv3 [RFC2740] is an IGP for routing IPv6 unicast packets.

   The link state based routing algorithm in OSPF and IS-IS calculates
   the shortest path from the source to the destination.  A routing
   table for routing unicast packets is generated on every participating
   IGP router.

   For some applications, path restrictions (e.g., link bandwidth) need
   to be considered.  As a result, extensions have been added to both
   IS-IS and OSPF to support traffic engineering based unicast routing
   as follows:




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   o  [RFC3630] - Traffic Engineering (TE) Extensions to OSPF Version 2

   o  [RFC3784] - Intermediate System to Intermediate System (IS-IS)
      Extensions for Traffic Engineering (TE)

   o  [RFC5329] - Traffic Engineering Extensions to OSPF Version 3

   A TE-capable IGP router, in addition to constructing a Link State
   Database, also constructs and maintains a TE Database that stores the
   traffic parameters (e.g., bandwidth) associated with links and nodes.
   This information is used for constraint based consideration during
   normal shortest path calculation.

3.  Scope

   To support IP multicast routing, either IS-IS or OSPF can be used
   and, in the architectural perspective of this document, there is no
   difference between them.  It requires no change in IS-IS or OSPF
   other than extensions to advertise and store distribution tree root
   node address and multicast group receiver information (refer to
   Section 4.2).

   Using IGP to route IP multicast packets is within IGP's architecture
   and routing paradigm.  IP multicast routing within an IGP area is
   called intra-area multicast routing, and IP multicast routing across
   IGP area is called inter-area multicast routing.  The concept, rules
   and behavior regarding intra-area unicast routing and inter-area
   unicast routing are all similarly applicable to intra-area and inter-
   area multicast routing, respectively.

   In an IPv4 network, IPv4 multicast packets can be routed using IS-IS
   (based on [RFC1195]) or OSPFv2 as introduced by this document.
   Similarly in an IPv6 network, IPv6 multicast packets can be routed
   using IS-IS (based on [RFC5308]) or OSPFv3 [RFC2740].  As the
   networking industry is currently under transition from IPv4 to IPv6,
   co-existence of the two is sometimes required.  Using the
   architecture described in this document, IPv4 multicast packets can
   be transported over an IPv6 network and IPv6 multicast packets can be
   transported over an IPv4 network.

4.  Routing IP Multicast Packets

   As illustrated in Figure 1, a single IGP can support both IP unicast
   and multicast routing.

   This section describes routing IP multicast packets using the
   existing network information that IGP collects, the related functions




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   and characteristics, along with the required extensions to existing
   IGPs.

                  +-------------+ +-------------+
                  |  IP Unicast | | IP Multicast|
                  |   Routing   | |  Routing    |
                  +------^------+ +------^------+
                         |               |
                  +------o------+ +------o------+
                  |   Unicast   | |  Multicast  |
                  |Routing Table| |Routing Table|
                  +------^------+ +------^------+
                         |               |
                  +------o------+ +------o------+
                  |  Shortest   | | Distribution|
                  |  Path Tree  | |  Path Tree  |
                  +------^------+ +------^------+
                         |               |
                  +------o---------------o------+
                  |     Link State Database     |
                  +--------------^--------------+
                                 |
                  +--------------o--------------+
                  |             IGP             |
                  |   +---------+  +---------+  |
                  |   |   OSPF  |  |  IS-IS  |  |
                  |   +---------+  +---------+  |
                  +-----------------------------+


   Figure 1: Using an IGP to Route both IP Unicast and Multicast Packets

4.1.  Multicast Distribution Tree

   To route IP multicast packets, a distribution tree is used.  A
   distribution tree consists of a tree root, one or more tree leaves,
   and some branch nodes.  The tree root is identified by the IP address
   (or Router ID) of an arbitrary router.  The tree root can be
   configured for a specific IP multicast address group, or
   automatically elected via an algorithm.  A tree leaf is an edge
   router and is a multicast destination.  A tree leaf is identified by
   an edge router's IP address and it is directly attached to one or
   more hosts that advertise the IP multicast group addresses (see
   Section 4.2 for details).  A router that is not a tree root but
   transmits a received IP multicast packet to one or more other router
   is called a Transit Router, which is a branch node in the
   distribution tree.




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   In the most general case, there is a single multicast distribution
   tree for each IP multicast address group.  Once a distribution tree
   is formed, an IP packet with the multicast destination address is
   forwarded according to the multicast distribution tree, that is, from
   the source to all tree leaves.

   Via configuration, additional distribution trees can be constructed
   for the same IP multicast address group, however with different tree
   roots and tree branches (paths).  This option provides a redundancy
   for routing path protection, and it can also be used to support load
   balance.

   When a leaf node of a multicast distribution tree is in the same IGP
   area as the tree root, the packet flow in the tree is within a single
   IGP area.  This behavior is called IGP intra-area multicast routing.

   When a leaf node of a multicast distribution tree is in a different
   IGP area from the tree root, the packet flow in the tree must cross
   IGP area boundary.  This behavior is called IGP inter-area multicast
   routing.

   Unicast routing in an IGP domain requires minimum configuration.
   This characteristic is inherited by multicast routing, that is, it
   requires minimal configuration and a multicast distribution tree can
   generally be constructed quickly in the same manner as a unicast
   routing table.

4.1.1.  Bidirectional Distribution Tree

   A multicast distribution tree is bi-directional.  In such a tree, IP
   multicast packets destined to a given multicast address could
   traverse any tree branch in either direction; that means any leaf
   node on the tree can be a multicast receiver and sender.  When a leaf
   node is a multicast source, it transmits the packet on the tree by
   which it is distributed to all other leaves of that tree.  The bi-
   directionality of distribution tree is useful for applications such
   as video conference.

   By configuration, a multicast distribution tree can be uni-
   directional, i.e., all leaf nodes can only receive multicast packets
   destined to a given multicast address.  In this scenario, the tree
   root may be the traffic source and if not, the source must unicast
   packets to the tree root, which then distributes the packets
   according to the distribution tree.  The uni-directionality of
   distribution tree is useful for applications such as video
   broadcasting.





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   For optimization purpose, i.e., to build an efficient pruned
   multicast distribution tree in both cases, care must be taken in
   choosing the location of tree root in a given network; e.g., to
   consider the average path length from the root to leaf nodes, the
   total links (branches) used for the distribution, etc.

4.2.  Advertising Multicast Group Membership

   In order to support multicast routing, an IGP must be extended to
   store and advertise IP multicast addresses in the similar manner
   currently for IP unicast addresses.

   Pairs of { multicast-group, host } can be configured on an edge
   router, or learned from the interaction with IGMP/MLD(see
   Section 4.3).  In either case, the router must advertise the IP
   multicast group membership throughout the IGP area.  The advertising,
   refresh, aging, and removal of IP multicast addresses are handled in
   the same manner as the existing database element, i.e., LSP in IS-IS
   and LSA in OSPF.

   IP multicast addresses can also be advertised across an IGP area
   boundary using mechanisms similar to those used for IP unicast
   addresses.  IP multicast addresses may be summarized in a way similar
   to IP unicast addresses for scaling purpose.

   The details of storing and advertising IP multicast address using IS-
   IS and OSPF will be specified in a separate documents.

4.3.  Requirements of Edge Routers

   To support routing IP multicast packets, edge routers, i.e., routers
   that have interfaces directly connected to IP hosts, are required to
   run IGMP (IGMPv2/[RFC2236] or IGMPv3/[RFC3376]) for IPv4 based hosts
   and MLD (MLD/[RFC2710] or MLDv2/[RFC3810]) for IPv6 based hosts.

   As the result of interaction with hosts, an edge router would build a
   Local Group Database where each entry is a { multicast-group, host }
   pair, which indicates that the attached host belonging to the IP
   multicast group.  This process is on-going in order to keep track of
   the IP group membership addresses of attached hosts according to
   protocol specification of IGMP/MLD.

   Use of the Local Group Database is two fold.  First, when an edge
   router receives an inbound IP multicast packet, it checks in the
   database to see if any entry has an IP multicast-group address
   matching the destination address in the received packet.  If so, the
   packet is forwarded to the local host(s); otherwise the packet is




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   dropped.  Note this behavior already exists on edge routers that
   support IP multicast forwarding.

   Second, an edge router is required to advertise/flood the IP
   multicast addresses learnt/withdrawn from IGMP/MLD to/from other
   routers in the same IGP area, in the similar manner as advertising/
   flooding its own interface IP addresses.  With this information, an
   IP multicast distribution tree can be built for each IP multicast
   address group.  The details for advertising multicast addresses by
   IS-IS and OSPF will be documented separately.

   In some deployment, a host as a multicast destination or source may
   connect to more than one edge routers for the purpose of reliability
   or/and load balance, which is normally termed multi-homing.  In this
   scenario, care must be taken in order to prevent forwarding loops or
   packets duplication.

4.4.  Intra-Area Multicast Routing

   An IP multicast distribution tree within an IGP area is a sub-graph
   of the IGP's area topology graph (see Section 2).  All routers that
   receive advertisement of IP multicast addresses in the IGP area must
   build the multicast distribution tree for each IP multicast address
   group.  The construction of the distribution is based on the IGP's
   Link State Database, which is currently used for routing IP unicast
   packets.  All routers in an IGP area must calculate and construct the
   intra-area distribution tree using IGP's Link State Database with the
   same algorithm, so that a pruned tree can be constructed for the
   distribution tree.  Care must be taken to avoid forwarding loops and
   routing optimization is highly desirable.

   The algorithm for constructing an IP multicast distribution tree, and
   other related functions, do not require changes to existing IGP
   function other than the addition of extensions.

   The specific algorithm and related details for intra-area multicast
   routing will be in a separate document.

4.5.  Inter-Area Multicast Routing

   In inter-area unicast routing, an IP packet from one IGP area
   forwarded to another area is sent to an area border node (ABR for
   OSPF) or L2 router (for IS-IS) first, which then forwards the packet
   to/in the neighboring area.  This is also the scenario for inter-area
   multicast routing, and as such, an ABR/L2-Router functions as a
   Transit Router, or a branch node in the multicast distribution tree.





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   Note that IGP's Link State Database is per area, so the multicast
   distribution tree constructed on routers in the transmitting area in
   generally terminated at the ABR/L2-Router due to lack of routing
   information.  The ABR/L2-Router in question would require extending
   the distribution in the receiving area based on the separate Link
   State Database.

   The specific procedure and related details for inter-area multicast
   routing will be in a separate document.

4.5.1.  Behavior of IS-IS Level 2 Router

   For IS-IS, the area boundary is in the border router, which extends
   the distribution tree for that area.

   To support inter-area multicast routing, an IS-IS Level 2 Router is
   required to propagate IP multicast addresses received in one area to
   all Level 2 Routers in other areas it is connected.  This behavior is
   similar to the advertisement of IS-IS Reachability Information PDU.

4.5.2.  Behavior of OSPF ABR

   For OSPF, the area boundary is on the ABR.  When an ABR attached to
   both transmitting area and receiving area, it extends the
   distribution tree in the receiving area.

   To support inter-area multicast routing, an OSPF ABR is required to
   propagate IP multicast addresses received in one area to all other
   areas to which it is attached.  This behavior is similar to the
   advertisement of OSPF Summary LSAs.

4.6.  Heterogeneous Environment

   To deploy IP multicast routing using IGP as described in this
   document, all routers in the IGP area are required to do the
   following:

   o  Implement the extensions to IS-IS (documented separately) or to
      OSPF (documented separately), depending on the IGP in use, for
      advertising multicast addresses.

   o  Support the new functions as described in Section 4.

   A heterogeneous network environment is one where not all routers in
   an IGP area implement the above extensions.  A multicast distribution
   tree within such an area cannot be segregated, but tunneling
   mechanism can be used to support multicast routing there.  When there
   are routers that would be on a multicast distribution tree but do not



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   supporting the required extensions, a tunnel is constructed
   connecting two routers capable of routing multicast across one or
   more intervening non-capable routers, such that the tunnel becomes a
   single branch on the distribution tree.  An IP multicast packet sent
   from a tunnel end to the other is encapsulated in an IP packet with
   the sending router's IP address as the source address and the
   receiving router's IP address as the destination address.

4.7.  TE (Traffic Engineering) Support

   The existing IP multicast routing practice (e.g., PIM) does not
   consider route constraints (e.g., link bandwidth).  Both OSPF and IS-
   IS support traffic engineering based unicast routing by constructing
   and maintaining a TE Database.  Like the Link State Database, the TE
   Database can also be used to support IP multicast routing when one or
   more path constraints are considered.

   To perform TE based multicast routing using IGP, routers must support
   TE extensions, and otherwise, there requires no other change in the
   IGP.

4.8.  Applications to Overlay Model

   Using a single IGP as a uniform routing engine for both IP unicast
   and multicast routing enables a simple but efficient IP networking
   fabric that can serve various applications above it using a overlay
   model.  These applications are viewed as at the service level,
   completely decoupled from the underneath IP networking fabric;
   however, they enjoy both IP unicast and multicast transportation
   infrastructure.  In the multicast perspective, the applications can
   be IP based, but can also be layer-2 based such as Ethernet.

4.9.  IPv6 and IPv4

   The architecture as outlined in this document supports IPv4 multicast
   routing in IPv4 networks, and also IPv6 multicast routing in IPv6
   networks.

   With mechanisms such as tunneling or address translation, the same
   architecture can also support IPv4 multicast routing in IPv6
   networks, and IPv6 multicast routing in IPv4 networks.  The details
   are specified in other documents.

5.  IANA Considerations

   This document requires no IANA actions.





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6.  Acknowledgement

7.  References

7.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

7.2.  Informative References

   [RFC1195]  Callon, R., "Use of OSI IS-IS for routing in TCP/IP and
              dual environments", RFC 1195, December 1990.

   [RFC2236]  Fenner, W., "Internet Group Management Protocol, Version
              2", RFC 2236, November 1997.

   [RFC2328]  Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998.

   [RFC2710]  Deering, S., Fenner, W., and B. Haberman, "Multicast
              Listener Discovery (MLD) for IPv6", RFC 2710, October
              1999.

   [RFC2740]  Coltun, R., Ferguson, D., and J. Moy, "OSPF for IPv6", RFC
              2740, December 1999.

   [RFC3376]  Cain, B., Deering, S., Kouvelas, I., Fenner, B., and A.
              Thyagarajan, "Internet Group Management Protocol, Version
              3", RFC 3376, October 2002.

   [RFC3630]  Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering
              (TE) Extensions to OSPF Version 2", RFC 3630, September
              2003.

   [RFC3784]  Smit, H. and T. Li, "Intermediate System to Intermediate
              System (IS-IS) Extensions for Traffic Engineering (TE)",
              RFC 3784, June 2004.

   [RFC3810]  Vida, R. and L. Costa, "Multicast Listener Discovery
              Version 2 (MLDv2) for IPv6", RFC 3810, June 2004.

   [RFC4601]  Fenner, B., Handley, M., Holbrook, H., and I. Kouvelas,
              "Protocol Independent Multicast - Sparse Mode (PIM-SM):
              Protocol Specification (Revised)", RFC 4601, August 2006.

   [RFC5308]  Hopps, C., "Routing IPv6 with IS-IS", RFC 5308, October
              2008.




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   [RFC5329]  Ishiguro, K., Manral, V., Davey, A., and A. Lindem,
              "Traffic Engineering Extensions to OSPF Version 3", RFC
              5329, September 2008.

   [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, August 2014.

Authors' Addresses

   Lucy Yong
   Huawei Technologies Ltd.
   Austin, TX
   USA

   Email: lucy.yong@huawei.com


   Dean Cheng
   Huawei Technologies Ltd.
   2330 Central Expressway
   Santa Clara, CA  95135
   USA

   Email: dean.cheng@huawei.com


   Weiguo Hao
   Huawei Technologies Ltd.
   101 Software Avenue
   Nanjing  210012
   China

   Email: haoweiguo@huawei.com


   Donald Eastlake
   Huawei Technologies Ltd.
   155 Beaver Street
   Milford, MA  01757
   USA

   Email: d3e3e3@gmail.com






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Internet-Draft         IGP Multicast Architecture             March 2015


   Andrew Qu
   MediaTek
   San Jose, CA  95134
   USA

   Email: laodulaodu@gmail.com


   Jon Hudson
   Brocade
   130 Holger Way
   San Jose, California  95134
   USA

   Email: jon.hudson@gmail.com


   Uma Chunduri
   Ericsson Inc.
   300 Holger Way
   San Jose, California  95134
   USA

   Email: uma.chunduri@ericsson.com



























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