Network Working Group                                              Z. Li
Internet-Draft                                                 S. Zhuang
Intended status: Standards Track                                   H. Ni
Expires: January 13, 2014                            Huawei Technologies
                                                           July 12, 2013


  Connecting IPv6 Multicast Islands over IPv4 MPLS Using IPv6 Provider
                           Edge Routers (6PE)
                       draft-li-idr-mcast-6pe-00

Abstract

   This document defines a new Network Layer Reachability Information
   (NLRI), called as the MCAST-6PE NLRI.  The MCAST-6PE NLRI is used to
   interconnect IPv6 C-Multicast islands over a Multiprotocol Label
   Switching (MPLS)-enabled IPv4 cloud.  This approach relies on IPv6
   Provider Edge routers (6PE), which can exchange the IPv6 C-Multicast
   reachability information transparently over the core using the
   Multiprotocol Border Gateway Protocol (MP-BGP) over IPv4.  This
   document describes the BGP encodings and procedures for exchanging
   the information elements required by IPv6 Multicast in 6PE.  MPLS-
   based Service Providers may use the 6PE Multicast mechanism to
   provide IPv6 Multicast service for customers.

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 RFC 2119 [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 January 13, 2014.




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Copyright Notice

   Copyright (c) 2013 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  MCAST-6PE NLRI  . . . . . . . . . . . . . . . . . . . . . . .   4
     3.1.  Intra-AS 6PE I-PMSI A-D Route . . . . . . . . . . . . . .   5
     3.2.  Inter-AS 6PE I-PMSI A-D route . . . . . . . . . . . . . .   6
     3.3.  6PE S-PMSI A-D Route  . . . . . . . . . . . . . . . . . .   6
     3.4.  6PE Leaf A-D Route  . . . . . . . . . . . . . . . . . . .   7
     3.5.  6PE Source Active A-D Route . . . . . . . . . . . . . . .   7
     3.6.  6PE C-Multicast Route . . . . . . . . . . . . . . . . . .   8
   4.  PMSI Tunnel Attribute . . . . . . . . . . . . . . . . . . . .   9
   5.  Source AS Extended Community  . . . . . . . . . . . . . . . .   9
   6.  Route Import Extended Community . . . . . . . . . . . . . . .   9
   7.  PE Distinguisher Labels Attribute . . . . . . . . . . . . . .  10
   8.  Operations  . . . . . . . . . . . . . . . . . . . . . . . . .  10
     8.1.  BGP-Based MCAST-6PE Membership Auto-Discovery . . . . . .  10
       8.1.1.  Intra-AS Operations . . . . . . . . . . . . . . . . .  10
       8.1.2.  Inter-AS Operations . . . . . . . . . . . . . . . . .  11
     8.2.  PE-PE Transmission of IPv6 C-Multicast Routing  . . . . .  11
       8.2.1.  Selecting the Upstream Multicast Hop (UMH)  . . . . .  11
       8.2.2.  Signaling P-tunnel  . . . . . . . . . . . . . . . . .  12
       8.2.3.  Use of BGP for Carrying IPv6 C-Multicast Routing  . .  12
       8.2.4.  Propagating IPv6 C-Multicast Routes by an ASBR  . . .  14
     8.3.  Using 6PE S-PMSI A-D Routes to Bind C-Trees to P-Tunnels   14
   9.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  14
   10. Security Considerations . . . . . . . . . . . . . . . . . . .  14
   11. References  . . . . . . . . . . . . . . . . . . . . . . . . .  14
     11.1.  Normative References . . . . . . . . . . . . . . . . . .  14
     11.2.  Informative References . . . . . . . . . . . . . . . . .  15
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  15





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1.  Introduction

   6PE[RFC4798] defines a mechanism to interconnect IPv6 islands over an
   MPLS-enabled IPv4 cloud using the IPv6 Provider Edge routers (6PE)
   approach.  In this document an 'IPv6 island' is a network running
   native IPv6 as per [RFC2460].  A typical example of an IPv6 island
   would be a customer's IPv6 site connected via its IPv6 Customer Edge
   (CE) router to one (or more) Dual Stack Provider Edge router(s) of a
   Service Provider.  These IPv6 Provider Edge routers (6PE) are
   connected to an IPv4 MPLS core network.  This document defines a new
   Network Layer Reachability Information (NLRI), called as the MCAST-
   6PE NLRI.  The MCAST-6PE NLRI is used to interconnect IPv6
   C-Multicast islands over a Multiprotocol Label Switching
   (MPLS)-enabled IPv4 cloud.  This approach relies on IPv6 Provider
   Edge routers (6PE), which can exchange the IPv6 C-Multicast
   reachability information transparently over the core using the
   Multiprotocol Border Gateway Protocol (MP-BGP) over IPv4.  This
   document describes the BGP encodings and procedures for exchanging
   the information elements required by IPv6 Multicast in 6PE.  MPLS-
   based Service Providers may use the 6PE Multicast mechanism to
   provide IPv6 Multicast service for customers.

2.  Terminology

   This document uses terminology from [RFC4798], [RFC6513], [RFC6514].

   Term Definition

   ----------- --------------------------------------------------

   6PE: IPv6 Provider Edge routers

   A-D: auto-discovery

   BGP: Border Gateway Protocol

   CE: customer edge

   C-G: customer multicast group address

   C-join: customer join message

   C-multicast: customer multicast

   C-PIM: customer PIM

   C-RP: customer rendezvous point




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   C-RPT: customer RP Tree

   C-S: customer multicast source address

   I-PMSI: inclusive PMSI

   LSP: label switched path

   MCAST: multicast

   mLDP: multipoint Label Distribution Protocol

   MP2MP: multipoint to multipoint

   MVPN: multicast VPN

   NG MVPN: next-generation multicast VPN

   NLRI: Network Layer Reachability Information

   OIL: outgoing interface list

   P2MP: point to multipoint PE: provider edge

   PIM: Protocol Independent Multicast

   PMSI: Provider Multicast Service Interface

   P-group: Provider multicast group

   P-join: Provider join message

   P-PIM: Provider PIM

   P-RP: Provider Rendezvous Point

   SAFI: Subsequent Address Family Identifier

   S-PMSI: Selective PMSI

   UMH: Upstream Multicast Hop

3.  MCAST-6PE NLRI

   This document defines a new BGP NLRI, called as the MCAST-6PE NLRI.
   Following is the format of the MCAST-6PE NLRI:





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                   +-----------------------------------+
                   |    Route Type (1 octet)           |
                   +-----------------------------------+
                   |     Length (1 octet)              |
                   +-----------------------------------+
                   | Route Type specific (variable)    |
                   +-----------------------------------+


   The Route Type field defines the encoding of the rest of MCAST-6PE
   NLRI (Route Type specific MCAST-6PE NLRI).  The Length field
   indicates the length in octets of the Route Type specific field of
   the MCAST-6PE NLRI.  This document defines the following Route Types
   for A-D routes:

   + 1 - Intra-AS 6PE I-PMSI A-D route;

   + 2 - Inter-AS 6PE I-PMSI A-D route;

   + 3 - 6PE S-PMSI A-D route;

   + 4 - 6PE Leaf A-D route;

   + 5 - 6PE Source Active A-D route.

   This document defines the following Route Types for IPv6 C-multicast
   routes:

   + 6 - 6PE Shared Tree Join route;

   + 7 - 6PE Source Tree Join route;

   The MCAST-6PE NLRI is carried in BGP using BGP Multiprotocol
   Extensions [RFC4760] with an AFI of 2 (IPv6 AFI), and a SAFI of
   MCAST-6PE [To be assigned by IANA].  The NLRI field in the
   MP_REACH_NLRI / MP_UNREACH_NLRI attribute contains the MCAST-6PE NLRI
   (encoded as specified above).  The following sections describe the
   format of the Route Type specific MCAST-6PE NLRI for various Route
   Types defined in this document.

3.1.  Intra-AS 6PE I-PMSI A-D Route

   An Intra-AS 6PE I-PMSI A-D Route Type specific MCAST-6PE NLRI
   consists of the following:







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                   +-----------------------------------+
                   |   Originating Router's IP Addr    |
                   +-----------------------------------+


   Originating Router's IP Addr filed set to the IP address of the MCAST
   6PE router originating this route, which is typically the primary
   loopback address of the MCAST 6PE router.

   All MCAST 6PE routers create and advertise a Type 1 intra-AS 6PE
   I-PMSI A-D route for IPv6 MCAST service to which they are connected.

3.2.  Inter-AS 6PE I-PMSI A-D route

   An Inter-AS 6PE I-PMSI A-D Route Type specific MCAST-6PE NLRI
   consists of the following:

                   +-----------------------------------+
                   |      Source AS (4 octets)         |
                   +-----------------------------------+


   The Source AS contains an Autonomous System Number (ASN), 4 octets.

   Two-octet ASNs are encoded in the two low-order octets of the Source
   AS field, with the two high-order octets set to zero.

   Type 2 routes are used for MCAST 6PE membership discovery between
   MCAST-6PE routers that belong to different ASes.

3.3.  6PE S-PMSI A-D Route

   A 6PE S-PMSI A-D Route Type specific MCAST-6PE NLRI consists of the
   following:

                   +-----------------------------------+
                   | Multicast Source Length (1 octet) |
                   +-----------------------------------+
                   | Multicast Source (variable)       |
                   +-----------------------------------+
                   | Multicast Group Length (1 octet)  |
                   +-----------------------------------+
                   | Multicast Group (variable)        |
                   +-----------------------------------+
                   | Originating Router's IP Addr      |
                   +-----------------------------------+





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   For MCAST-6PE, the Multicast Source field contains the C-S address
   i.e. the address of the multicast source, which is an IPv6 address,
   then the value of the Multicast Source Length field is 128 bits.

   For MCAST-6PE, the Multicast Group field contains the C-G address
   i.e. the address of the multicast group, which is an IPv6 address,
   then the value of the Multicast Group Length field is 128 bits.

   The Originating Router's IP Addr filed set to the IP address of the
   MCAST-6PE router originating this route, which is typically the
   primary loopback address of the MCAST-6PE router.

   A sender MCAST-6PE that initiates a selective P-tunnel is required to
   originate a Type 3 6PE S-PMSI A-D route with the appropriate PMSI
   attribute.

3.4.  6PE Leaf A-D Route

   A 6PE Leaf A-D Route Type specific MCAST-6PE NLRI consists of the
   following:

                   +-----------------------------------+
                   |      Route Key (variable)         |
                   +-----------------------------------+
                   |   Originating Router's IP Addr    |
                   +-----------------------------------+


   The Route Key field contains the original Type 3 route received.  The
   Originating Router's IP Addr filed set to the IP address of the
   MCAST-6PE originating the 6PE leaf A-D route, typically the primary
   loopback address.

   A 6PE Leaf A-D routes may be originated as a result of processing a
   received Inter-AS 6PE I-PMSI A-D route [Type 2] or 6PE S-PMSI A-D
   route [Type 3].  A 6PE Leaf A-D route is originated in these
   situations only if the received route has a PMSI Tunnel attribute
   whose "Leaf Information Required" bit is set to 1.

   Typically a receiver MCAST-PE router responds to a Type 3 route by
   originating a Type 4 6PE leaf A-D route if it has local receivers
   interested in the traffic transmitted on the selective P-tunnel.  The
   Type 4 route informs the sender MCAST-6PE of the leaf MCAST-6PE
   routers.

3.5.  6PE Source Active A-D Route





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   A 6PE Source Active A-D Route Type specific MCAST-6PE NLRI consists
   of the following:

                   +-----------------------------------+
                   | Multicast Source Length (1 octet) |
                   +-----------------------------------+
                   | Multicast Source (variable)       |
                   +-----------------------------------+
                   | Multicast Group Length (1 octet)  |
                   +-----------------------------------+
                   | Multicast Group (variable)        |
                   +-----------------------------------+


   For MCAST-6PE, the Multicast Source field contains the C-S address
   i.e. the address of the multicast source, which is an IPv6 address,
   then the value of the Multicast Source Length field is 128 bits.

   For MCAST-6PE, the Multicast Group field contains the C-G address
   i.e. the address of the multicast group, which is an IPv6 address,
   then the value of the Multicast Source Length field is 128 bits.

   Type 5 6PE Source Active A-D routes carry information about active
   IPv6 Multicast sources and the groups to which they are transmitting
   data.  These routes can be generated by any MCAST-6PE router that
   becomes aware of an active source.

3.6.  6PE C-Multicast Route

   A 6PE Shared Tree Join Route and a 6PE Source Tree Join Route Type
   specific MCAST-6PE NLRI consists of the following:

                   +-----------------------------------+
                   |    Source AS (4 octets)           |
                   +-----------------------------------+
                   | Multicast Source Length (1 octet) |
                   +-----------------------------------+
                   | Multicast Source (variable)       |
                   +-----------------------------------+
                   | Multicast Group Length (1 octet)  |
                   +-----------------------------------+
                   | Multicast Group (variable)        |
                   +-----------------------------------+


   The Source AS contains an ASN, 4 octets.  Two-octet ASNs are encoded
   in the low-order two octets of the Source AS field.




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   For MCAST-6PE, the Multicast Source field contains an IPv6 address,
   then the value of the Multicast Source Length field is 128 bits.  For
   a 6PE Shared Tree Join Route, the Multicast Source field contains the
   C-RP address; for a 6PE Source Tree Join Route, the Multicast Source
   field contains the C-S address.

   For MCAST-6PE, the Multicast Group field contains an IPv6 address,
   then the value of the Multicast Group Length field is 128 bits.  The
   Multicast Group field contains the C-G address.

   The 6PE C-Multicast Routes exchange between MCAST-6PE routers refers
   to the propagation of C-joins from receiver MCAST-6PEs to the sender
   MCAST-6PEs.

   In a 6PE MCAST Network, IPv6 C-joins received by MCAST-6PE Router
   from the CEs are encoded as BGP 6PE C-Multicast Routes and advertised
   via 6PE C-Multicast Routes towards the sender MCAST-6PEs.  Two types
   of 6PE C-Multicast Routes are specified.  The Type 6 6PE C-Multicast
   Routes are used in representing information contained in a shared
   tree (C-*, C-G) join.  The Type 7 6PE C-Multicast Routes are used in
   representing information contained in a source tree (C-S, C-G) join.

4.  PMSI Tunnel Attribute

   The usage of PMSI Tunnel Attribute is described in [RFC6514].

5.  Source AS Extended Community

   The Source AS is an AS-specific Extended Community, of an extended
   type, and is transitive across AS boundaries [RFC4360].  The Global
   Administrator field of this Community MUST be set to the ASN of the
   MCAST-6PE router.  The Local Administrator field of this Community
   MUST be set to 0.

   The usage of a received Source AS Extended Community in MCAST 6PE is
   the same as described in [RFC6514].

6.  Route Import Extended Community

   This document defines a new BGP Extended Community called "Route
   Import", type value is to be assigned by IANA.The Route Import
   Extended Community is an IP-address-specific extended community that
   is used for importing IPv6 C-Multicast routes in the active sender
   MCAST-6PE router's MCAST-6PE routing table to which the source is
   attached.  For MCAST-6PE Network case, for constructing IPv6
   C-Multicast Import RT, the Local Administrator is set to 0 and the
   Global Administrator field MUST be set to an IP address of the MCAST-
   6PE router.



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7.  PE Distinguisher Labels Attribute

   The usage of PE Distinguisher Labels Attribute is described in
   [RFC6513].

8.  Operations

8.1.  BGP-Based MCAST-6PE Membership Auto-Discovery

   This section specifies procedures for the auto-discovery of MCAST-6PE
   memberships and the distribution of information used to instantiate
   I-PMSIs.

   There are two MCAST-6PE auto-discovery mechanisms, dubbed "intra- AS"
   and "inter-AS" respectively.  The intra-AS mechanisms provide auto-
   discovery within a single AS.  The inter-AS mechanisms provide auto-
   discovery across multiple ASes when segmented inter-AS tunnels are
   being used.

   BGP-Based MCAST-6PE Membership Auto-Discovery is done by means of a
   new address family, the MCAST-6PE address family.  Any PE that
   attaches to a MCAST-6PE service MUST issue a BGP Update message
   containing a NLRI in this address family, along with a specific set
   of attributes.

8.1.1.  Intra-AS Operations

   This section describes exchanges of Type 1 Intra-AS 6PE I-PMSI A-D
   routes originated/received by PEs within the same AS.

   To participate in the MCAST-6PE auto-discovery, a PE router that
   provides MCAST 6PE service MUST originate an Intra-AS 6PE I-PMSI A-D
   route and advertises this route in IBGP.  The route is constructed as
   follows.

   The route carries a single MCAST-6PE NLRI with the Originating
   Router's IP Addr field set to the IP address of the MCAST 6PE router
   originating this route.  Note that the <Originating Router's IP Addr>
   uniquely identifies a given MCAST-6PE router.

   The route carries the PMSI Tunnel attribute if and only if an I-PMSI
   is used for the MCAST-6PE (the conditions under which an I-PMSI is
   used can be found in [RFC6513]).  Depending on the technology used
   for the P-tunnel for the MCAST-6PE on the PE, the PMSI Tunnel
   attribute of the Intra-AS 6PE I-PMSI A-D route is the same as
   described in [RFC6514].





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   The Next Hop field of the MP_REACH_NLRI attribute of the route MUST
   be set to the same IP address as the one carried in the Originating
   Router's IP Addr field.

   When PE-PE Type 1 intra-AS 6PE I-PMSI A-D routes are exchanged among
   all provider routers, every PE can know the MCAST-6PE neighbors to
   itself.

8.1.2.  Inter-AS Operations

   This section applies only to the case where segmented inter-AS
   tunnels are used.

   Type 2 routes are used for MCAST 6PE membership discovery between
   MCAST-6PE routers that belong to different ASs.

   If an ASBR is configured to support MCAST 6PE service, the ASBR MUST
   participate in the intra-AS MCAST 6PE auto-discovery procedures, for
   that MCAST 6PE within the ASBR's own AS, as specified in Section&#160
   ;"Intra-AS Operations".

   A Type 2 Inter-AS 6PE I-PMSI A-D route for MCAST 6PE originated by an
   ASBR within a given AS is propagated via BGP to other ASes.

   The route carries a single MCAST-6PE NLRI with the Source AS field
   set to the ASBR's own AS.

   When re-advertising an Inter-AS 6PE I-PMSI A-D route, the ASBR MUST
   set the Next Hop field of the MP_REACH_NLRI attribute to a routable
   IP address of the ASBR.

8.2.  PE-PE Transmission of IPv6 C-Multicast Routing

   IPv6 C-Multicast Routing Information is exchanged among PEs by using
   6PE C-multicast routes that are carried using an MCAST-6PE NLRI.
   These routes are originated and propagated as follows.

8.2.1.  Selecting the Upstream Multicast Hop (UMH)

   Section 5.1 of [RFC6513] describes the method of Selecting the
   Upstream Multicast Hop (UMH).  Constructing the C-Multicast Import RT
   as specified in Section 7 of [RFC6514].

   For a PE as the MCAST-6PE sender, issues the UMH route through a 6PE
   UCAST route carrying Route Import Extended Community and Source AS
   Extended Community.





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   The Route Import Extended Community is an IP-address-specific
   extended community that is used for importing IPv6 C-Multicast routes
   in the active sender MCAST-6PE's MCAST-6PE routing table to which the
   source is attached.  For MCAST-6PE Network case, for constructing
   IPv6 C-Multicast Import RT, the Local Administrator is set to 0 and
   the Global Administrator field MUST be set to an IP address of the
   MCAST-6PE router.

8.2.2.  Signaling P-tunnel

   The PMSI tunnel attribute carries information about the P-tunnel.  In
   a MCAST-6PE Network, the sender PE router sets up the P-tunnel, and
   therefore is responsible for originating the PMSI tunnel attribute.
   The PMSI tunnel attribute can be attached to Type 1, Type 2, and Type
   3 routes.

   The MCAST-6PE sender router, attaches a PMSI tunnel attribute to Type
   1 Intra-AS 6PE I-PMSI A-D Route, begins to signal P-tunnel for MCAST-
   6PE Network.

   MCAST-6PE sender sends Type 1 route to other PEs, when other PEs
   receive the Type 1 route with PMSI tunnel attribute from MCAST-6PE
   sender, then join the P-tunnel.

8.2.3.  Use of BGP for Carrying IPv6 C-Multicast Routing

   Part of the procedures for constructing MCAST-6PE NLRI depends on the
   multicast routing protocol between CE and PE (C-multicast protocol).

8.2.3.1.  PIM as the C-Multicast Protocol

   Whenever (a) a C-PIM instance on a particular PE creates a new
   (C-S,C-G) state, and (b) the selected upstream PE for C-S (see
   [RFC6513]) is not the local PE, then the local PE MUST originate a
   C-multicast route of type Source Tree Join.  The Multicast Source
   field in the MCAST-6PE NLRI of the route is set to C-S; the Multicast
   Group field is set of C-G.

   This C-multicast route is said to "correspond" to the C-PIM (C-S,C-G)
   state.

   The semantics of the route are such that the PE has one or more
   receivers for (C-S,C-G) in the sites connected to the PE (the route
   has the (C-S,C-G) Join semantics).

   Whenever a C-PIM instance on a particular PE deletes a (C-S,C-G)
   state, the corresponding C-multicast route MUST be withdrawn.  (The
   withdrawal of the route has the (C-S,C-G) Prune semantics).  The



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   MCAST-6PE NLRI of the withdrawn route is carried in the
   MP_UNREACH_NLRI attribute.

8.2.3.1.1.  Source Tree Join (C-S, C-G)

   When receiver PE receives a source tree join (C-S, C-G) from CE, it
   does a route look up for C-S. If there is more than one route, the
   receiver PE chooses a single forwarder PE.  The procedures used for
   choosing a single forwarder are outlined in [RFC6514].  When the C-S
   route has been selected, the receiver PE will originate a Type 7
   route, carrying Route Import attribute extracting from the C-S route,
   and sends this Type 7 route to other PEs.

   When sender PE receives a Type 7 route, if RT-Import of this route
   belongs to itself, it translates this Type 7 route back into a C-join
   message and sends it to its CE.

8.2.3.1.2.  Shared Tree Join (C-*, C-G)

   When receiver PE receives a shared tree join (C-*, C-G) from CE, it
   does a route look up for C-RP.  If there is more than one route, the
   receiver PE chooses a single forwarder PE.  The procedures used for
   choosing a single forwarder are outlined in [RFC6514].

   When the C-RP route has been selected, the receiver PE will create a
   Type 6 route.  If this PE has not received a Type 5 route, it will
   not advertise it.

   When source connected to CE is active, register message is sent to
   the sender PE.  The sender PE originates a Type 5 route, and sends to
   other MCAST-6PE routers.

   When receiver PE receives the Type 5 route from the remote PE, it
   will originate a Type 7 route based on Type 5 and Type 6, then it
   sends the Type 7 route carrying Route Import attribute extracting
   from the C-RP route, and sends this Type 7 route to other PEs.

   When sender PE receives the Type 7 routes, compares local RT-Import
   to RT received with Type 7 routes.  If match, it imports the Type 7
   routes, then translates the Type 7 route back into a C-join message
   and passes the C-join messages to CE.

8.2.3.2.  mLDP as the C-Multicast Protocol

   The construction of the MCAST-6PE NLRI of C-multicast routes for the
   case where the C-multicast protocol is mLDP [mLDP] is described in
   [RFC6514].




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8.2.4.  Propagating IPv6 C-Multicast Routes by an ASBR

   The mechanisms for IPv6 C-Multicast Routes by an ASBR are the same as
   the MVPN case described in section 11.2 of [RFC6514].

8.3.  Using 6PE S-PMSI A-D Routes to Bind C-Trees to P-Tunnels

   BGP-based procedures for using 6PE S-PMSIs A-D routes to bind
   (C-S,C-G) trees to P-tunnels are the same as the MVPN case described
   in section 12 of [RFC6514].

9.  IANA Considerations

   This document defines a new BGP Extended Community called "Route
   Import" (Type value is to be assigned by IANA).  This Community is IP
   address specific, of an extended type, and is transitive.

   This document defines a new NLRI, called as MCAST-6PE NLRI, to be
   carried in BGP using multiprotocol extensions.  It requires
   assignment of a new SAFI.  This is to be assigned by IANA.

10.  Security Considerations

   This document raises no new security issues.  Security considerations
   for the base protocol are covered in [RFC6513] and [RFC6514].

11.  References

11.1.  Normative References

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

   [RFC4271]  Rekhter, Y., Li, T., and S. Hares, "A Border Gateway
              Protocol 4 (BGP-4)", RFC 4271, January 2006.

   [RFC4360]  Sangli, S., Tappan, D., and Y. Rekhter, "BGP Extended
              Communities Attribute", RFC 4360, February 2006.

   [RFC4364]  Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
              Networks (VPNs)", RFC 4364, February 2006.

   [RFC4760]  Bates, T., Chandra, R., Katz, D., and Y. Rekhter,
              "Multiprotocol Extensions for BGP-4", RFC 4760, January
              2007.






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   [RFC4798]  De Clercq, J., Ooms, D., Prevost, S., and F. Le Faucheur,
              "Connecting IPv6 Islands over IPv4 MPLS Using IPv6
              Provider Edge Routers (6PE)", RFC 4798, February 2007.

   [RFC6513]  Rosen, E. and R. Aggarwal, "Multicast in MPLS/BGP IP
              VPNs", RFC 6513, February 2012.

   [RFC6514]  Aggarwal, R., Rosen, E., Morin, T., and Y. Rekhter, "BGP
              Encodings and Procedures for Multicast in MPLS/BGP IP
              VPNs", RFC 6514, February 2012.

11.2.  Informative References

   [RFC3031]  Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol
              Label Switching Architecture", RFC 3031, January 2001.

   [RFC4272]  Murphy, S., "BGP Security Vulnerabilities Analysis", RFC
              4272, January 2006.

   [RFC4610]  Farinacci, D. and Y. Cai, "Anycast-RP Using Protocol
              Independent Multicast (PIM)", RFC 4610, August 2006.

   [RFC5331]  Aggarwal, R., Rekhter, Y., and E. Rosen, "MPLS Upstream
              Label Assignment and Context-Specific Label Space", RFC
              5331, August 2008.

   [RFC6388]  Wijnands, IJ., Minei, I., Kompella, K., and B. Thomas,
              "Label Distribution Protocol Extensions for Point-to-
              Multipoint and Multipoint-to-Multipoint Label Switched
              Paths", RFC 6388, November 2011.

Authors' Addresses

   Zhenbin Li
   Huawei Technologies
   Huawei Bld., No.156 Beiqing Rd.
   Beijing  100095
   China

   Email: lizhenbin@huawei.com











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   Shunwan Zhuang
   Huawei Technologies
   Huawei Bld., No.156 Beiqing Rd.
   Beijing  100095
   China

   Email: zhuangshunwan@huawei.com


   Hui Ni
   Huawei Technologies
   Huawei Bld., No.156 Beiqing Rd.
   Beijing  100095
   China

   Email: nihui@huawei.com



































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