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(The document does seem to have the reference to RFC 2119 which the ID-Checklist requires). (Using the creation date from RFC6513, updated by this document, for RFC5378 checks: 2005-06-01) -- The document seems to lack a disclaimer for pre-RFC5378 work, but may have content which was first submitted before 10 November 2008. If you have contacted all the original authors and they are all willing to grant the BCP78 rights to the IETF Trust, then this is fine, and you can ignore this comment. If not, you may need to add the pre-RFC5378 disclaimer. (See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- The document date (August 15, 2016) is 2808 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) No issues found here. Summary: 0 errors (**), 0 flaws (~~), 2 warnings (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 BESS Working Group E. Rosen, Ed. 3 Internet-Draft Juniper Networks, Inc. 4 Updates: 6513,6514 (if approved) K. Subramanian 5 Intended status: Standards Track Sproute Networks 6 Expires: February 16, 2017 Z. Zhang 7 Juniper Networks, Inc. 8 August 15, 2016 10 Ingress Replication Tunnels in Multicast VPN 11 draft-ietf-bess-ir-05 13 Abstract 15 RFCs 6513, 6514, and other RFCs describe procedures by which a 16 Service Provider may offer Multicast VPN service to its customers. 17 These procedures create point-to-multipoint (P2MP) or multipoint-to- 18 multipoint trees across the Service Provider's backbone. One type of 19 P2MP tree that may be used is known as an "Ingress Replication (IR) 20 tunnel". In an IR tunnel, a parent node need not be "directly 21 connected" to its child nodes. When a parent node has to send a 22 multicast data packet to its child nodes, it does not use layer 2 23 multicast, IP multicast, or MPLS multicast to do so. Rather, it 24 makes n individual copies, and then unicasts each copy, through an IP 25 or MPLS unicast tunnel, to exactly one child node. While the prior 26 MVPN specifications allow the use of IR tunnels, those specifications 27 are not always very clear or explicit about how the MVPN protocol 28 elements and procedures are applied to IR tunnels. This document 29 updates RFCs 6513 and 6514 by adding additional details that are 30 specific to the use of IR tunnels. 32 Status of This Memo 34 This Internet-Draft is submitted in full conformance with the 35 provisions of BCP 78 and BCP 79. 37 Internet-Drafts are working documents of the Internet Engineering 38 Task Force (IETF). Note that other groups may also distribute 39 working documents as Internet-Drafts. The list of current Internet- 40 Drafts is at http://datatracker.ietf.org/drafts/current/. 42 Internet-Drafts are draft documents valid for a maximum of six months 43 and may be updated, replaced, or obsoleted by other documents at any 44 time. It is inappropriate to use Internet-Drafts as reference 45 material or to cite them other than as "work in progress." 47 This Internet-Draft will expire on February 16, 2017. 49 Copyright Notice 51 Copyright (c) 2016 IETF Trust and the persons identified as the 52 document authors. All rights reserved. 54 This document is subject to BCP 78 and the IETF Trust's Legal 55 Provisions Relating to IETF Documents 56 (http://trustee.ietf.org/license-info) in effect on the date of 57 publication of this document. Please review these documents 58 carefully, as they describe your rights and restrictions with respect 59 to this document. Code Components extracted from this document must 60 include Simplified BSD License text as described in Section 4.e of 61 the Trust Legal Provisions and are provided without warranty as 62 described in the Simplified BSD License. 64 Table of Contents 66 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 67 2. What is an IR P-tunnel? . . . . . . . . . . . . . . . . . . . 5 68 3. How are IR P-tunnels Identified? . . . . . . . . . . . . . . 7 69 4. How to Join an IR P-tunnel . . . . . . . . . . . . . . . . . 9 70 4.1. Advertised IR P-tunnels . . . . . . . . . . . . . . . . . 9 71 4.1.1. If the 'Leaf Info Required Bit' is Set . . . . . . . 10 72 4.1.2. If the 'Leaf Info Required Bit' is Not Set . . . . . 10 73 4.2. Unadvertised IR P-tunnels . . . . . . . . . . . . . . . . 11 74 5. The PTA's 'Tunnel Identifier' Field . . . . . . . . . . . . . 11 75 6. A Note on IR P-tunnels and 'Discarding Packets from the Wrong 76 PE' . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 77 7. The PTA's 'MPLS Label' Field . . . . . . . . . . . . . . . . 13 78 7.1. Leaf A-D Route Originated by an Egress PE . . . . . . . . 14 79 7.2. Leaf A-D Route Originated by an Intermediate Node . . . . 16 80 7.3. Intra-AS I-PMSI A-D Route . . . . . . . . . . . . . . . . 17 81 8. How A Child Node Prunes Itself from an IR P-tunnel . . . . . 17 82 9. Parent Node Actions Upon Receiving Leaf A-D Route . . . . . . 18 83 10. Use of Timers when Switching UMH . . . . . . . . . . . . . . 19 84 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20 85 12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 20 86 13. Security Considerations . . . . . . . . . . . . . . . . . . . 20 87 14. References . . . . . . . . . . . . . . . . . . . . . . . . . 20 88 14.1. Normative References . . . . . . . . . . . . . . . . . . 20 89 14.2. Informative References . . . . . . . . . . . . . . . . . 21 90 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22 92 1. Introduction 94 RFCs 6513, 6514, and others describe procedures by which a Service 95 Provider (SP) may offer Multicast VPN (MVPN) service to its 96 customers. These procedures create point-to-multipoint (P2MP) or 97 multipoint-to-multipoint (MP2MP) tunnels, called "P-tunnels" 98 (Provider-tunnels), across the SP's backbone network. Customer 99 multicast traffic is carried through the P-tunnels. 101 A number of different P-tunnel technologies are supported. One of 102 the supported P-tunnel technologies is known as "ingress replication" 103 or "unicast replication". We will use the acronym "IR" to refer to 104 this P-tunnel technology. 106 An IR P-tunnel is a P2MP tree, but a given node on the tree is not 107 necessarily "directly attached" to its parent node or to its child 108 nodes. To send a multicast data packet from a parent node to one of 109 its child nodes, the parent node encapsulates the packet and then 110 unicasts it through a tunnel to the child node. The tunnel may be a 111 P2P (point-to-point) or MP2P (multipoint-to-point) MPLS LSP (label 112 switched path) or a unicast IP tunnel. If a node on an IR tree has n 113 child nodes, and has a multicast data packet that must be sent along 114 the tree, the parent node makes n individual copies of the data 115 packet, and then sends each copy, through a unicast tunnel, to 116 exactly one child node. No lower layer multicast technology is used 117 when sending traffic from a parent node to a child node; multiple 118 copies of the packet may therefore be sent out a single interface. 120 With the single exception of IR, the P-tunnel technologies supported 121 by the MVPN specifications are pre-existing IP multicast or MPLS 122 multicast technologies. Each such technology has its own set of 123 specifications, its own setup and maintenance protocols, its own 124 syntax for identifying specific multicast trees, and its own 125 procedures for enabling a router to be added to or removed from a 126 particular multicast tree. For IR P-tunnels, on the other hand, 127 there is no prior specification for setting up and maintaining the 128 P2MP trees; the procedures and protocol elements used for setting up 129 and maintaining the P2MP trees are specified in the MVPN 130 specifications themselves, and all the signaling/setup is done by 131 using the BGP A-D (Auto-Discovery) routes that are defined in 132 [RFC6514]. (The unicast tunnels used to transmit multicast data from 133 one node to another in an IR P-tunnel may of course have their own 134 setup and maintenance protocols, e.g., [RFC5036], [RFC3209].) 136 Since the transmission of a multicast data packet along an IR 137 P-tunnel is done by transmitting the packet through a unicast tunnel, 138 previous RFCs sometimes speak of an IR P-tunnel as "consisting of" a 139 set of unicast tunnels. However, that way of speaking is not quite 140 accurate. For one thing, it obscures the fact that an IR P-tunnel is 141 really a P2MP tree, whose nodes must maintain multicast state in both 142 the control and data planes. For another, it obscures the fact the 143 unicast tunnels used by a particular IR P-tunnel need not be specific 144 to that P-tunnel; a single unicast tunnel can carry the multicast 145 traffic of many different IR P-tunnels (and can also carry unicast 146 traffic as well). 148 In this document, we provide a clearer and more explicit conceptual 149 model for IR P-tunnels, clarifying the relationship between an IR 150 P-tunnel and the unicast tunnels that are used for data transmission 151 along the IR P-tunnel. 153 Section 5 of [RFC6514] defines a BGP Path Attribute known as the 154 "PMSI (Provider Multicast Service Interface) Tunnel attribute" (PTA). 155 This attribute contains a field known as the "Tunnel Identifier" 156 field. For most P-tunnel technologies, the PTA's "Tunnel Identifier" 157 field is used to identify a P-tunnel (i.e., to identify a P2MP or 158 MP2MP tree). However, when IR P-tunnels are used, the PTA "Tunnel 159 Identifier" field does not actually identify an IR P-tunnel. In some 160 cases it identifies one of the P-tunnel's constituent unicast 161 tunnels, and in other cases it is not used to identify a tunnel at 162 all. In this document, we provide an explicit specification for how 163 IR P-tunnels are actually identified. 165 Some of the MVPN specifications use phrases like "join the identified 166 P-tunnel", even though there has up to now not been an explicit 167 specification of how to identify an IR P-tunnel, of how a router 168 joins such a P-tunnel, or of how a router prunes itself from such a 169 P-tunnel. In this document, we make these procedures more explicit. 171 [RFC6514] does provide a method for binding an MPLS label to a 172 P-tunnel, but does not discuss the label allocation policies that are 173 needed for correct operation when the P-tunnel is an IR P-tunnel. 174 Those policies are discussed in this document. 176 This document does not provide any new protocol elements, or any 177 fundamentally new procedures; its purpose is to make explicit just 178 how a router is to use the protocol elements and procedures of 179 [RFC6513] and [RFC6514] to identify an IR P-tunnel, to join an IR 180 P-tunnel, and to prune itself from an IR P-tunnel. 182 This document also discusses the MPLS label allocation policies that 183 need to be supported when binding MPLS labels to IR P-tunnels, and 184 the timer policies that need to be supported when switching a 185 customer multicast flow from one IR P-tunnel to another. These are 186 procedures that are not clearly specified in [RFC6513] or [RFC6514]. 187 As the material in this document must be understood in order to 188 properly implement IR P-tunnels, this document is considered to 189 update [RFC6513] and [RFC6514]. 191 This document also discusses the application of "seamless multicast" 192 [RFC7524] and "extranet" [RFC7900] procedures to IR P-tunnels. 194 This draft does not discuss the use of IR P-tunnels to support a VPN 195 customer's use of Bidirectional Protocol Independent Multicast 196 (BIDIR-PIM). [RFC7740] explains how to adapt the procedures of 197 [RFC6513], [RFC6514], and [RFC7582] so that a customer's use of 198 BIDIR-PIM can be supported by IR P-tunnels. 200 In the event of any conflict between this document and either 201 [RFC6513] or [RFC6514], this document takes precedence. 203 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 204 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 205 "OPTIONAL", when and only when appearing in all capital letters, are 206 to be interpreted as described in [RFC2119]. 208 2. What is an IR P-tunnel? 210 An IR P-tunnel is a P2MP tree. Its nodes are BGP speakers that 211 support the MVPN procedures of [RFC6514] and related RFCs. In 212 general, the nodes of an IR P-tunnel are either Provider Edge (PE) 213 routers, Autonomous System Border Routers (ASBRs), or (if [RFC7524] 214 is supported) Area Border Routers (ABRs). (MVPN procedures are 215 sometimes used to support non-MVPN, or "global table" multicast; one 216 way of doing this is defined in [RFC7524]. Another way is defined in 217 [RFC7716]. In such cases, IR P-tunnels can be used outside the 218 context of MVPN.) 220 MVPN P-tunnels may be either "segmented" or "non-segmented" (as these 221 terms are defined in [RFC6513] and [RFC6514]). 223 A "non-segmented" IR P-tunnel is a two-level P2MP tree, consisting 224 only of a root node and a set of nodes that are children of the root 225 node. When used in an MVPN context, the root is an ingress PE, and 226 the child nodes of the root are the egress PEs. 228 In a segmented P-tunnel, IR may be used for some or all of the 229 segments. If a particular segment of a segmented P-tunnel uses IR, 230 then the root of that segment may have child nodes that are ABRs or 231 ASBRs, rather than egress PEs. 233 As with any type of P2MP tree, each node of an IR P-tunnel holds 234 "multicast state" for the P-tunnel. That is, each node knows the 235 identity of its parent node on the tree, and each node knows the 236 identities of its child nodes on the tree. In the MVPN specs, the 237 "parent" node is also known as the "Upstream Multicast Hop" or "UMH". 238 Note that the "UMH" may be a PE, an ASBR, or (if procedures from 239 [RFC7524] are being used) an ABR. (In [RFC7524], the term "upstream 240 node" is used instead of "UMH".) 242 What distinguishes an IR P-tunnel from any other kind of P2MP tree is 243 the method by which a data packet is transmitted from a parent node 244 to a child node. To transmit a multicast data packet from a parent 245 node to a child node along a particular IR P-tunnel, the parent node 246 does the following: 248 o It labels the packet with a label (call it a "P-tunnel label") 249 that the child node has assigned to that P-tunnel, 251 o It then places the packet in a unicast encapsulation and unicasts 252 the packet to the child node. That is, the parent node sends the 253 packet through a "unicast tunnel" to a particular child node. 254 This unicast tunnel need not be specially created to be part of 255 the IR P-tunnel; it can be any P2P or MP2P unicast tunnel that 256 will get the packets from the parent node to the child node. A 257 single such unicast tunnel may be carrying multicast data packets 258 of several different P2MP trees, and may also be carrying unicast 259 data packets. 261 The parent node repeats this process for each child node, creating 262 one copy for each child node, and sending each copy through a unicast 263 tunnel to corresponding child node. It does not use layer 2 264 multicast, IP multicast, or MPLS multicast to transmit packets to its 265 child nodes. As a result, multiple copies of each packet may be sent 266 out a single interface; this may happen, e.g., if that interface is 267 the next hop interface, according to unicast routing, from the parent 268 node to several of the child nodes. 270 Since data traveling along an IR P-tunnel is always unicast from 271 parent node to child node, it can be convenient to think of an IR 272 P-tunnel as a P2MP tree whose arcs are unicast tunnels. However, it 273 is important to understand that the unicast tunnels need not be 274 specific to any particular IR P-tunnel. If R1 is the parent node of 275 R2 on two different IR P-tunnels, a single unicast tunnel from R1 to 276 R2 may be used to carry data along both IR P-tunnels. All that is 277 required is that when the data packets arrive at R2, R2 will see the 278 "P-tunnel label" at the top of the packets' label stack; R2's further 279 processing of the packets will depend upon that label. Note that the 280 same unicast tunnel between R1 and R2 may also be carrying unicast 281 data packets. 283 Typically the unicast tunnels are the Label Switched Paths (LSPs) 284 that already exist to carry unicast traffic; either MP2P LSPs created 285 by LDP (Label Distribution Protocol, [RFC5036]) or P2P LSPs created 286 by RSVP-TE (Resource Reservation Protocol - Traffic Engineering, 287 [RFC3209]). However, any other kind of unicast tunnel may be used. 288 A unicast tunnel may have an arbitrary number of intermediate 289 routers; those routers do not maintain any multicast state for the IR 290 P-tunnel, and in general are not even aware of its existence. 292 As with all other P-tunnel types, an IR P-tunnel may be used to 293 instantiate either an Inclusive PMSI or a Selective PMSI. See 294 Section 3.2 of [RFC6513] for an explanation of those concepts. 296 3. How are IR P-tunnels Identified? 298 There are four MVPN BGP route types in which P-tunnels can be 299 identified: Intra-AS I-PMSI A-D (Intra Autonomous System Inclusive 300 PMSI A-D) routes, Inter-AS I-PMSI A-D routes, S-PMSI (Selective PMSI) 301 A-D routes, and Leaf A-D routes. (These route types are all defined 302 in [RFC6514]). 304 Whenever it is necessary to identify a P-tunnel in a route of one of 305 these types, a "PMSI Tunnel Attribute" (PTA) is added to the route. 306 As defined in [RFC6514] section 5, the PTA contains four fields: 307 "Tunnel Type", "MPLS Label", "Tunnel Identifier", and "Flags". 308 [RFC6514] defines only one bit in the "Flags" field, the "Leaf 309 Information Required" bit. 311 If a route identifies an IR P-tunnel, the "Tunnel Type" field of its 312 PTA is set to the value 6, meaning "Ingress Replication". 314 Most types of P-tunnel are associated with specific protocols that 315 are used to set up and maintain tunnels of that type. For example, 316 if the "Tunnel Type" field is set to 2, meaning "mLDP P2MP LSP", the 317 associated setup protocol is mLDP [RFC6388]. The associated setup 318 protocol always has a method of identifying the tunnels that it sets 319 up. For example, mLDP uses a "FEC element" (Forwarding Equivalence 320 Class Element) to identify a tree. If the "Tunnel type" field is set 321 to 3, meaning "PIM SSM Tree" (Protocol Independent Multicast Source- 322 Specific Tree), the associated setup protocol is PIM, and "(S,G)" is 323 used to identify the tree. In these cases, the "Tunnel Identifier" 324 field of the PTA carries a tree identifier as defined by the setup 325 protocol used for the particular tunnel type. 327 IR P-tunnels, on the other hand, are entirely setup and maintained by 328 the use of BGP A-D routes, and are not associated with any other 329 setup protocol. (The unicast tunnels used to transmit multicast data 330 along an IR P-tunnel may have their own setup and maintenance 331 protocols, of course.) The means of identifying a P-tunnel is very 332 different for IR P-tunnels than for other types of P-tunnel: 334 When an IR P-tunnel is identified in an S-PMSI A-D route, an 335 Intra-AS I-PMSI A-D route, or an Inter-AS I-PMSI A-D route (we 336 will refer to these three route types as "advertising A-D 337 routes"), its identifier is hereby defined to be the NLRI (Network 338 Layer Reachability Information) of that route. See sections 4.1, 339 4.2, and 4.3 of [RFC6514] for the specification of these NLRIs. 340 Note that the IR P-tunnel identifier includes the "route type" and 341 "length" octets of the NLRI. 343 To reiterate: 345 The identifier of the IR P-tunnel does not appear in the PTA at 346 all; the "Tunnel Identifier" field of the PTA does not contain the 347 identifier of the IR P-tunnel. 349 Rather,the identifier of the IR P-tunnel appears in the "Network 350 Layer Reachability Information" (NLRI) field of the A-D routes 351 that are used to advertise and to setup the IR P-tunnel. 353 Note that an advertising A-D route is considered to identify an IR 354 P-tunnel only if it carries a PTA whose "Tunnel Type" field is set to 355 "IR". 357 When an IR P-tunnel is identified in an S-PMSI A-D route or in an 358 Inter-AS I-PMSI A-D route, the "Leaf Info Required" bit of the Flags 359 field of the PTA MUST be set. 361 In an advertising A-D route: 363 o If the "Leaf Info Required" bit of the Flags field of the PTA is 364 set, then the "Tunnel Identifier" field of the PTA has no 365 significance whatsoever, and MUST be ignored upon reception. 367 Note that, per RFC6514, the length of the "Tunnel Identifier" 368 field of the PTA is variable, and is inferred from the length of 369 the PTA. Even when this field is of no significance, its length 370 MUST be the length of an IP address in the address space of the 371 SP's backbone, as specified in section 4.2 of [RFC6515]. In this 372 case, it is RECOMMENDED that it be set to a routable address of 373 the router that constructed the PTA. (While it might make more 374 sense to allow or even require the field to be omitted entirely, 375 that might raise issues of backwards compatibility with 376 implementations that were designed prior to the publication of 377 this document.) 379 o If the "Leaf Info Required" bit is not set, the "Tunnel 380 Identifier" field of the PTA does have significance, but it does 381 not identify the IR P-tunnel. The use of the PTA's "Tunnel 382 Identifier" field in this case is discussed in Section 5 of this 383 document. 385 Note that according to the above definition, there is no way for two 386 different advertising A-D routes (i.e., two advertising A-D routes 387 with different NLRIs) to advertise the same IR P-tunnel. In the 388 terminology of [RFC6513], an IR P-tunnel can instantiate only a 389 single PMSI. If an ingress PE, for example, wants to bind two 390 customer multicast flows to a single IR P-tunnel, it must advertise 391 that IR P-tunnel either in an I-PMSI A-D route or in an S-PMSI A-D 392 route whose NLRI contains wildcards ([RFC6625]). 394 When an IR P-tunnel is identified in a Leaf A-D route, its identifier 395 is the "route key" field of the route's NLRI. See section 4.4 of 396 [RFC6514]. 398 A Leaf A-D route is considered to identify an IR P-tunnel only if it 399 carries a PTA whose "Tunnel Type" field is set to "IR". In this type 400 of route, the "Tunnel Identifier" field of the PTA does have 401 significance, but it does not identify the IR P-tunnel. The use of 402 the PTA's "Tunnel Identifier" field in this case is discussed in 403 Section 5. 405 4. How to Join an IR P-tunnel 407 The procedures for joining an IR P-tunnel depend upon whether the 408 P-tunnel has been previously advertised, and if so, upon how the 409 P-tunnel was advertised. Note that joining an unadvertised IR 410 P-tunnel is only possible when using the "Global Table Multicast" 411 procedures of [RFC7524]. 413 4.1. Advertised IR P-tunnels 415 The procedures in this section apply when the IR P-tunnel to be 416 joined has been advertised in an S-PMSI A-D route, an Inter-AS I-PMSI 417 A-D route, or an Intra-AS I-PMSI A-D route. 419 The procedures for joining an advertised IR P-tunnel depend upon 420 whether the A-D route that advertises the IR P-tunnel has the "Leaf 421 Info Required" bit set in its PTA. 423 4.1.1. If the 'Leaf Info Required Bit' is Set 425 The procedures in this section apply when the P-tunnel to be joined 426 has been advertised in a route whose PTA has the "Leaf Info Required 427 Bit" set. 429 The router joining a particular IR P-tunnel must determine its UMH 430 for that P-tunnel. If the route that advertised the IR P-tunnel 431 contains a P2MP Segmented Next Hop Extended Community, the UMH is 432 determined from the value of this community (see [RFC7524]). 433 Otherwise the UMH is determined from the route's next hop (see 434 [RFC6514]). 436 Once the UMH is determined, the router joining the IR P-tunnel 437 originates a Leaf A-D route. The NLRI of the Leaf A-D route is 438 formed following the procedures of [RFC6514]. As a result, the NLRI 439 of the Leaf A-D route will contain the IR P-tunnel identifier defined 440 in Section 3 above as its "route key". The UMH MUST be identified by 441 attaching an "IP Address Specific Route Target" (or an "IPv6 Address 442 Specific Route Target") to the Leaf A-D route. The IP address of the 443 UMH appears in the "global administrator" field of the Route Target 444 (RT). Details can be found in [RFC6514] and [RFC7524]. 446 The Leaf A-D route MUST also contain a PTA whose fields are set as 447 follows: 449 o The "Tunnel Type" field is set to "IR". 451 o The "Tunnel Identifier" field is set as described in Section 5 of 452 this document. (Note that this field does not contain the IR 453 P-tunnel Identifier that is defined in Section 3.) 455 o The "MPLS Label" field is set to a non-zero value. This is the 456 "P-tunnel label". The value must be chosen so as to satisfy 457 various constraints, as discussed in Section 7 this document. 459 4.1.2. If the 'Leaf Info Required Bit' is Not Set 461 The procedures in this section apply when the IR P-tunnel to be 462 joined has been advertised in a route whose PTA does not have the 463 "Leaf Info Required Bit" set. This can only be the case if the IR 464 P-tunnel was advertised in an Intra-AS I-PMSI A-D route. 466 If an IR P-tunnel is advertised in the Intra-AS I-PMSI A-D routes 467 originated by the PE routers of a given MVPN, the Intra-AS I-PMSI can 468 be thought of as being instantiated by a set of IR P-tunnels. Each 469 PE is the root of one such IR P-tunnel, and the other PEs are 470 children of the root. A PE simultaneously joins all these P-tunnels 471 by originating (if it hasn't already done so) an Intra-AS I-PMSI A-D 472 route with a PTA whose fields are set as follows: 474 o The "Tunnel Type" field is set to "IR". 476 o The "Tunnel Identifier" field is set as described in Section 5 of 477 this document. (Note that this field does not contain the IR 478 P-tunnel Identifier that defined in Section 3.) 480 o The "MPLS Label" field MUST be set to a non-zero value. This 481 label value will be used by the child node to associate a received 482 packet with the I-PMSI of a particular MVPN. The MPLS label 483 allocation policy must be such as to ensure that the binding from 484 label to I-PMSI is one-to-one. 486 The NLRI and the RTs of the originated I-PMSI A-D route are set as 487 specified in [RFC6514]. 489 4.2. Unadvertised IR P-tunnels 491 In [RFC7524], a procedure is defined for "Global Table Multicast", in 492 which a P-tunnel can be joined even if the P-tunnel has not been 493 previously advertised. See the sections of that document entitled 494 "Leaf A-D Route for Global Table Multicast" and "Constructing the 495 Rest of the Leaf A-D Route". The route key of the Leaf A-D route has 496 the form of the "S-PMSI Route-Type Specific NLRI" in this case, and 497 that should be considered to be the IR P-tunnel identifier. Note 498 that the procedure for finding the UMH is different in this case; the 499 UMH is the next hop of the best UMH-eligible route towards the 500 "ingress PE". See the section of that document entitled "Determining 501 the Upstream ABR/PE/ASBR (Upstream Node)". 503 5. The PTA's 'Tunnel Identifier' Field 505 As discussed in Section 1, when the "Tunnel Type" field of a PTA is 506 set to "IR", the "Tunnel Identifier" field of that PTA does not 507 contain the IR P-tunnel identifier. This section (Section 5) 508 specifies the procedures for setting the "Tunnel Identifier" field of 509 the PTA when the "Tunnel Type" field of the PTA is set to "IR". 511 If the "Tunnel Type" field of a PTA is set to "IR", its "Tunnel 512 Identifier" field is significant only when one of the following two 513 conditions holds: 515 o The PTA is carried by a Leaf A-D route, or 517 o The "Leaf Information Required" bit of the "Flags" field of the 518 PTA is not set. 520 If one of these conditions holds, then the "Tunnel Identifier" field 521 must contain a routable IP address of the originator of the route. 522 (See [RFC6514] sections 9.2.3.2.1 and 9.2.3.4.1 for the detailed 523 specification of the contents of this field.) This address is used 524 by the UMH to determine the unicast tunnel that it will use in order 525 to send data, along the IR P-tunnel identified by the route key, to 526 the originator of the Leaf A-D route. 528 The means by which the unicast tunnel is determined from this IP 529 address is outside the scope of this document. The means by which 530 the unicast tunnel is set up and maintained is also outside the scope 531 of this document. 533 Section 4 of [RFC6515] MUST be applied when a PTA is carried in a 534 Leaf A-D route, and describes how to determine whether the "Tunnel 535 Identifier" field carries an IPv4 or an IPv6 address. 537 If neither of the above conditions hold, then the "Tunnel Identifier" 538 field is of no significance, and MUST be ignored upon reception. 540 6. A Note on IR P-tunnels and 'Discarding Packets from the Wrong PE' 542 Section 9.1.1 of [RFC6513] specifies a procedure known as "Discarding 543 Packets from the Wrong PE". When an egress PE receives a multicast 544 data packet, this procedure requires it to determine the packet's 545 ingress PE. 547 In this document, we assume that when a packet has reached an egress 548 PE via an IR P-tunnel, the egress PE will infer the identity of the 549 packet's ingress PE by examining the packet's P-tunnel label. 551 Section 7 specifies certain constraints on the way in which the 552 P-tunnel label is allocated for a given P-tunnel. In general, if 553 these constraints are followed, an egress PE will be able to infer 554 the identity of a packet's ingress PE from the P-tunnel label, and 555 hence will be able to apply the procedures of Section 9.1.1 of 556 [RFC6513]. This method of identifying a packet's ingress PE works 557 exactly the same when the unicast tunnels are IP tunnels as it does 558 when the unicast tunnels are MPLS LSPs. 560 However, if the egress PE joined a particular IR P-tunnel using the 561 procedures of Section 4.1.2, then when the egress PE receives a 562 packet through that P-tunnel, it will not be able to infer the 563 identity of the packet's ingress PE from the P-tunnel label, and thus 564 will not be able to apply the procedures of Section 9.1.1 of 565 [RFC6513]. 567 One might think that if a particular IR P-tunnel uses IP unicast 568 tunnels rather than MPLS LSPs, an egress PE could identify the 569 ingress PE by inspecting the IP source address field of the 570 encapsulating IP header. However, there are several reasons why this 571 procedure is not desirable: 573 o When segmented P-tunnels are being used, the IP source address 574 field of the encapsulating IP header might not contain the address 575 of the ingress PE. 577 o Even if the IP source address field of the encapsulating IP header 578 does identify the ingress PE, there is no guarantee that the IP 579 source address in that header is the same as the IP address used 580 by the ingress PE for the MVPN signaling procedures. 582 o To apply the procedures of Section 9.1.1 of [RFC6513] when 583 extranet functionality [RFC7900] is supported, it is necessary to 584 infer a packet's ingress VRF (Virtual Routing and Forwarding 585 table), not merely its ingress PE. This can be inferred from the 586 P-tunnel label (assuming that the label is allocated following the 587 procedures of Section 7), but can not be inferred from the IP 588 source address of the encapsulating IP header. 590 We therefore assume in this document that if the procedures of 591 Section 9.1.1 of [RFC6513] are to be applied to packets traveling 592 through IR P-tunnels, those procedures will be based on the P-tunnel 593 label, even if the IR P-tunnel is using IP unicast tunnels. 595 This means that if an egress PE joined a particular IR P-tunnel using 596 the procedures of Section 4.1.2, duplicate prevention on that IR 597 P-tunnel requires the use of either Single Forwarder Selection 598 ([RFC6513] section 9.1.2) or native PIM procedures ([RFC6513] section 599 9.1.3). 601 7. The PTA's 'MPLS Label' Field 603 When the "Tunnel Type" field of a PTA is set to "IR", the "MPLS 604 Label" field is not always significant. It is significant only under 605 the following conditions: 607 1. Either the PTA is being carried in a Leaf A-D route, or 609 2. the "Leaf Information Required" flag of the PTA is NOT set. 611 Note that the "Leaf Information Required" flag of the PTA is always 612 set when a PTA specifying an IR P-tunnel is carried in an S-PMSI A-D 613 route or in an Inter-AS I-PMSI A-D route; thus the "MPLS Label" field 614 of the PTA is never significant when the PTA is carried by one of 615 these route types. The "MPLS Label" field is significant only when 616 the PTA appears either in a Leaf A-D route or in an Intra-AS I-PMSI 617 A-D route that does not have the "Leaf Information Required" bit set. 618 In these cases, the MPLS label is the label that the originator of 619 the route is assigning to the IR P-tunnel(s) identified by the 620 route's NLRI. (That is, the MPLS label assigned in the PTA is what 621 we have called the "P-tunnel label".) 623 In those cases where the "MPLS Label" field is not significant, it 624 SHOULD be set to zero upon transmission and MUST be ignored upon 625 reception. 627 7.1. Leaf A-D Route Originated by an Egress PE 629 As previously stated, when a Leaf A-D route is used to join an IR 630 P-tunnel, the "route key" of the Leaf A-D route is the P-tunnel 631 identifier. 633 We now define the notion of the "root of an IR P-tunnel". 635 o If the identifier of an IR P-tunnel is of the form of an S-PMSI 636 NLRI, the "root" of the IR P-tunnel is the router identified in 637 the "Originating Router's IP Address" field of that NLRI. 639 o If the identifier of an IR P-tunnel is of the form specified in 640 Section "Leaf A-D Route for Global Table Multicast" of [RFC7524], 641 the "root" of the IR P-tunnel is the router identified in the 642 "Ingress PE's IP Address" field of that NLRI. 644 o If the identifier of an IR P-tunnel is of the form of an Intra-AS 645 I-PMSI NLRI, the "root" of the IR P-tunnel is the router 646 identified in the "Originating Router's IP Address" field of that 647 NLRI. 649 o If the identifier of an IR P-tunnel is of the form of an Inter-AS 650 I-PMSI NLRI, the "root" of the IR P-tunnel is same as the 651 identifier of the IR P-tunnel, i.e., the combination of an RD and 652 an AS. 654 Note that if an IR P-tunnel is segmented, the root of the IR 655 P-tunnel, by this definition, is actually the root of the entire 656 P-tunnel, not the root of the local segment. In this case, there may 657 be segments upstream that are not themselves IR P-tunnels. However, 658 the egress PE is aware only of the final segment of the P-tunnel, and 659 hence considers the P-tunnel to be an IR P-tunnel. 661 In order to apply the procedures of RFC 6513 Section 9.1.1 662 ("Discarding Packets from Wrong PE"), the following condition MUST be 663 met by the MPLS label allocation policy: 665 Suppose an egress PE originates two Leaf A-D routes, each with a 666 different route key in its NLRI, and each with a PTA specifying a 667 "Tunnel Type" of "IR". Thus each of the Leaf A-D routes 668 identifies a different IR P-tunnel. Suppose further that each of 669 those IR P-tunnels has a different root. Then the egress PE MUST 670 NOT specify the same MPLS label in both PMSI Tunnel attributes. 672 That is, to apply the "Discarding Packets from the Wrong PE" 673 duplicate prevention procedures ([RFC6513] section 9.1.1), the same 674 MPLS label MUST NOT be assigned to two IR P-tunnels that have 675 different roots. 677 If segmented P-tunnels are in use, the above rule is necessary but 678 not sufficient to prevent a PE from forwarding duplicate data to the 679 CEs. For various reasons, a given egress PE or egress ABR or egress 680 ASBR may decide to change its parent node, on a given segmented 681 P-tunnel, from one router to another. It does this by changing the 682 RT of the Leaf A-D route that it originated in order to join that 683 P-tunnel. Once the RT is changed, there may be a period of time 684 during which the old parent node and the new parent node are both 685 sending data of the same multicast flow. To ensure that the egress 686 node not forward duplicate data, whenever the egress node changes the 687 RT that it attaches to a Leaf A-D route, it MUST also change the 688 "MPLS Label" specified in the Leaf A-D route's PTA. This allows the 689 egress router to distinguish between packets arriving on a given 690 P-tunnel from the old parent and packets arriving on that same 691 P-tunnel from the new parent. At any given time, a router MUST 692 consider itself to have only a single parent node on a given 693 P-tunnel, and MUST discard traffic that arrives on that P-tunnel from 694 a different parent node. 696 If extranet functionality [RFC7900] is not implemented in a 697 particular egress PE, or if an egress PE is provisioned with the 698 knowledge that extranet functionality is not needed, the PE may adopt 699 the policy of assigning a label that is unique for the ordered triple 700 . This will enable the egress PE to 701 apply the duplicate prevention procedures discussed above, and to 702 determine the VRF to which an arriving packet must be directed. 704 However, this policy is not sufficient to support the "Discard 705 Packets from the Wrong P-tunnel" procedures that are specified in 706 [RFC7900]. To support those procedures, the labels specified in the 707 PTA of Leaf A-D routes originated by a given egress PE MUST be unique 708 for the ordered triple , where the "root 709 RD" is taken from the RD field of the IR P-tunnel identifier. (All 710 forms of IR P-tunnel identifier contain an embedded "RD" field.) 711 This policy is also sufficient for supporting non-extranet cases, but 712 in some cases may result in the use of more labels than the policy of 713 the previous paragraph. 715 7.2. Leaf A-D Route Originated by an Intermediate Node 717 When a P-tunnel is segmented, there will be "intermediate nodes", 718 i.e., nodes that have a parent and also have children on the 719 P-tunnel. Each intermediate node is a leaf node of an "upstream 720 segment" and a root node of one or more "downstream segments". The 721 intermediate node needs to set up its forwarding state so that data 722 it receives on the upstream segment gets transmitted on the proper 723 downstream segments. 725 If the upstream segment is instantiated by IR, the intermediate node 726 will need to originate a Leaf A-D route to join that segment, and 727 will need to allocate a downstream-assigned MPLS label to advertise 728 in the MPLS label field of the Leaf A-D route's PTA. Section 7.1 729 specifies constraints on the label allocation policy for egress PEs; 730 this section specifies constraints on the label allocation policy for 731 intermediate nodes. 733 Suppose intermediate node N originates two Leaf A-D routes, one whose 734 route key is K1, and one whose route key is K2, where K1 != K2. The 735 respective PTAs of these Leaf A-D routes MUST specify distinct non- 736 zero MPLS labels, UNLESS the following conditions all hold: 738 1. N's parent node for P-tunnel K1 is the same as N's parent node 739 for P-tunnel K2. 741 2. N's forwarding state is such that any packet it receives from 742 P-tunnel K1 is forwarded to the exact same set of downstream 743 neighbors as any packet it receives from P-tunnel K2. 745 3. For each downstream neighbor D to which N sends the packets it 746 receives from P-tunnels K1 and K2, N's forwarding state is such 747 that it applies the exact same encapsulation to packets it 748 forwards from either tunnel to D. (E.g., if N uses MPLS to 749 forward the packets to D, it pushes the exact same set of labels 750 on packets from P-tunnel K1 as it pushes on packets from P-tunnel 751 K2.) 753 Of course, N MAY always specify distinct non-zero labels in each of 754 the Leaf A-D routes that it originates. 756 Note that the rules of this section apply whenever the upstream 757 P-tunnel segment is an IR P-tunnel. These rules hold whether or not 758 some or all of the downstream segments are other types of P-tunnels. 760 If the P-tunnels from N to a particular downstream neighbor D are IR 761 P-tunnels, then condition 3 above will hold with respect to D only if 762 the following conditions all hold as well: 764 o N has received and installed a Leaf A-D route from D, whose route 765 key is K1, and which carries an IP-address-specific RT identifying 766 N, 768 o N has received and installed a Leaf A-D route from D, whose route 769 key is K2, and which carries an IP-address-specific RT identifying 770 N, 772 o Those two Leaf A-D routes specify the same MPLS label in their 773 respective PTAs. 775 7.3. Intra-AS I-PMSI A-D Route 777 When a router joins a set of IR P-tunnels using the procedures of 778 Section 4.1.2 of this document, the procedures of section 9.1.1 of 779 [RFC6513] cannot be applied, no matter what the label allocation 780 policy is. In this case, the ingress PE is the same as the UMH, but 781 it is not possible to assign a label uniquely to a particular ingress 782 PE or UMH. However, the label in the MPLS label field of the PTA 783 MUST NOT appear in the MPLS label field of the PTA carried by any 784 other route originated by the same router. 786 8. How A Child Node Prunes Itself from an IR P-tunnel 788 If a particular IR P-tunnel was joined via the procedures of 789 Section 4.1.2 of this document, a router can prune itself from the 790 P-tunnel by withdrawing the Intra-AS I-PMSI A-D route it used to join 791 the P-tunnel. This is not usually done unless the router is removing 792 itself entirely from a particular MVPN. 794 The procedures in the remainder of this section apply when a router 795 joined a particular IR P-tunnel by originating a Leaf A-D route (as 796 described in Section 4.1.1 or Section 4.2 of this document). 798 If a router no longer has a need to receive any multicast data from a 799 given IR P-tunnel, it may prune itself from the P-tunnel by 800 withdrawing the Leaf A-D route it used to join the tunnel. This is 801 done, e.g., if the router no longer needs any of the flows traveling 802 over the P-tunnel, or if all the flows the router does need are being 803 received over other P-tunnels. 805 A router that is attached to a particular IR P-tunnel via a 806 particular parent node may determine that it needs to stay joined to 807 that IR P-tunnel, but via a different parent node. This can happen, 808 for example, if there is a change in the Next Hop or the P2MP 809 Segmented Next Hop Extended Community of the S-PMSI A-D route in 810 which that P-tunnel was advertised. In this case, the router changes 811 the Route Target of the Leaf A-D route it used to join the IR 812 P-tunnel, so that the Route Target now identifies the new parent 813 node. 815 A parent node must notice when a child node has been pruned from a 816 particular tree, as this will affect the parent node's multicast data 817 state. Note that the pruning of a child node may appear to the 818 parent node as the explicit withdrawal of a Leaf A-D route, or it may 819 appear as a change in the Route Target of a Leaf A-D route. If the 820 Route Target of a particular Leaf A-D route previously identified a 821 particular parent node, but changes so that it no longer does so, the 822 effect on the multicast state of the parent node is the same as if 823 the Leaf A-D route had been explicitly withdrawn. 825 9. Parent Node Actions Upon Receiving Leaf A-D Route 827 These actions are detailed in [RFC6514] and [RFC7524]. Two points of 828 clarification are made: 830 o If a router R1 receives and installs a Leaf A-D route originated 831 by router R2, R1's multicast state is affected only if the Leaf 832 A-D route carries an "IP Address Specific RT" (or "IPv6 Address 833 Specific RT") whose "global administrator" field identifies R1. 835 (This is as specified in [RFC6514] and [RFC7524].) If a Leaf A-D 836 route's RT does not identify R1, but then changes so that it does 837 identify R1, R1 must take the same actions it would take if the 838 Leaf A-D route were newly received. 840 o It is possible that router R1 will receive and install a Leaf A-D 841 route originated by router R2, where: 843 * the route's RT identifies R1, 845 * the route's NLRI contains a route key whose first octet 846 indicates that it is identifying a P-tunnel advertised in an 847 S-PMSI A-D route, 849 * R1 has neither originated nor installed any such S-PMSI A-D 850 route. 852 If at some later time, R1 installs the corresponding S-PMSI A-D 853 route, and the Leaf A-D route is still installed, and the Leaf A-D 854 route's RT still identifies R1, then R1 MUST follow the same 855 procedures it would have followed if the S-PMSI A-D route had been 856 installed before the Leaf A-D route was installed. Implementers must 857 not assume that events occur in the "usual" or "expected" order. 859 10. Use of Timers when Switching UMH 861 Consider a child node that has joined a particular IR P-tunnel via a 862 particular UMH. To do so, it will have originated a Leaf A-D route 863 with an RT that identifies the UMH. Suppose the child node now 864 determines (for whatever reason) that it needs to change its UMH for 865 that P-tunnel. It does this by: 867 o modifying the RT of the Leaf A-D route, so that the RT now 868 identifies the new parent rather than the old one, and by 870 o modifying the PTA of the Leaf A-D route, changing the MPLS Label 871 field as discussed in Section 7. 873 Note that, in accordance with the procedures of [RFC6514] and of 874 Section 4 of this document, the NLRI of the Leaf A-D route is not 875 modified; only the RT and the PTA are changed. 877 It is desirable for such a "switch of UMH" to be done using a "make 878 before break" technique, so that the old UMH does not stop 879 transmitting packets of the given P-tunnel to the child until the new 880 UMH has a chance to start transmitting packets of the given P-tunnel 881 to the child. However, the control plane operation (i.e., modifying 882 the RT and PTA of the Leaf A-D route) does not permit the child node 883 to first join the IR P-tunnel via the new UMH, and then later prune 884 itself from the old UMH. Rather, a single control plane operation 885 has both effects. 887 Therefore, the old UMH MUST continue transmitting to the child node 888 for a period of time after it sees the child's Leaf A-D route being 889 withdrawn (or its RT changing to identify a different UMH). This 890 timer (the "parent-continues" timer) SHOULD have a default value of 891 60 seconds, and SHOULD be configurable. 893 By the procedures of Section 7, the child node will have advertised a 894 different label for the IR P-tunnel to the new UMH than it had 895 advertised to the old UMH. This allows it to distinguish the packets 896 of that IR P-tunnel transmitted by the new UMH from packets of that 897 IR P-tunnel transmitted by the old UMH. At any given time, the child 898 node will accept packets of that IR P-tunnel from only one parent 899 node, and will discard packets of that IR P-tunnel that are received 900 from the other. To achieve "make before break" functionality, the 901 child node needs to continue to accept packets from the old UMH for a 902 period of time. After this period, it will discard any packets from 903 the given IR P-tunnel that it receives from the old UMH, and will 904 only accept such packets from the new UMH. 906 Once the child node modifies the RT of its Leaf A-D route, it MUST 907 run a timer (the "switch-parents-delay" timer). This timer SHOULD 908 default to 30 seconds, and SHOULD be configurable. The child node 909 MUST continue to accept packets of the given IR P-tunnel from the old 910 UMH until the timer expires. However, once the child node receives a 911 packet of the given IR P-tunnel from the new UMH, it MAY consider the 912 switch-parents-delay timer to have expired. 914 The "parent-continues" timer MUST be longer than the "switch-parents- 915 delay" timer. Note that both timers are specific to a given IR 916 P-tunnel. 918 11. IANA Considerations 920 This document contains no actions for IANA. 922 12. Acknowledgments 924 The authors wish to thank Yakov Rekhter for his contributions to this 925 work. We also wish to thank Huajin Jeng and Samir Saad for their 926 contributions, and to thank Thomas Morin for pointing out (both 927 before and after the document was written) some of the issues that 928 needed further elaboration. We also thank Lucy Yong for her review 929 and comments. 931 Section 7.1 discusses the importance of having an MPLS label 932 allocation policy that, when ingress replication is used, allows an 933 egress PE to infer the identity of a received packet's ingress PE. 934 This issue was first raised in earlier work by Xu Xiaohu. 936 13. Security Considerations 938 No security considerations are raised by this document beyond those 939 already discussed in [RFC6513] and [RFC6514]. 941 14. References 943 14.1. Normative References 945 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 946 Requirement Levels", BCP 14, RFC 2119, 947 DOI 10.17487/RFC2119, March 1997, 948 . 950 [RFC6513] Rosen, E., Ed. and R. Aggarwal, Ed., "Multicast in MPLS/ 951 BGP IP VPNs", RFC 6513, DOI 10.17487/RFC6513, February 952 2012, . 954 [RFC6514] Aggarwal, R., Rosen, E., Morin, T., and Y. Rekhter, "BGP 955 Encodings and Procedures for Multicast in MPLS/BGP IP 956 VPNs", RFC 6514, DOI 10.17487/RFC6514, February 2012, 957 . 959 [RFC6515] Aggarwal, R. and E. Rosen, "IPv4 and IPv6 Infrastructure 960 Addresses in BGP Updates for Multicast VPN", RFC 6515, 961 DOI 10.17487/RFC6515, February 2012, 962 . 964 14.2. Informative References 966 [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., 967 and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP 968 Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001, 969 . 971 [RFC5036] Andersson, L., Ed., Minei, I., Ed., and B. Thomas, Ed., 972 "LDP Specification", RFC 5036, DOI 10.17487/RFC5036, 973 October 2007, . 975 [RFC6388] Wijnands, IJ., Ed., Minei, I., Ed., Kompella, K., and B. 976 Thomas, "Label Distribution Protocol Extensions for Point- 977 to-Multipoint and Multipoint-to-Multipoint Label Switched 978 Paths", RFC 6388, DOI 10.17487/RFC6388, November 2011, 979 . 981 [RFC6625] Rosen, E., Ed., Rekhter, Y., Ed., Hendrickx, W., and R. 982 Qiu, "Wildcards in Multicast VPN Auto-Discovery Routes", 983 RFC 6625, DOI 10.17487/RFC6625, May 2012, 984 . 986 [RFC7524] Rekhter, Y., Rosen, E., Aggarwal, R., Morin, T., 987 Grosclaude, I., Leymann, N., and S. Saad, "Inter-Area 988 Point-to-Multipoint (P2MP) Segmented Label Switched Paths 989 (LSPs)", RFC 7524, DOI 10.17487/RFC7524, May 2015, 990 . 992 [RFC7582] Rosen, E., Wijnands, IJ., Cai, Y., and A. Boers, 993 "Multicast Virtual Private Network (MVPN): Using 994 Bidirectional P-Tunnels", RFC 7582, DOI 10.17487/RFC7582, 995 July 2015, . 997 [RFC7716] Zhang, J., Giuliano, L., Rosen, E., Ed., Subramanian, K., 998 and D. Pacella, "Global Table Multicast with BGP Multicast 999 VPN (BGP-MVPN) Procedures", RFC 7716, 1000 DOI 10.17487/RFC7716, December 2015, 1001 . 1003 [RFC7740] Zhang, Z., Rekhter, Y., and A. Dolganow, "Simulating 1004 Partial Mesh of Multipoint-to-Multipoint (MP2MP) Provider 1005 Tunnels with Ingress Replication", RFC 7740, 1006 DOI 10.17487/RFC7740, January 2016, 1007 . 1009 [RFC7900] Rekhter, Y., Ed., Rosen, E., Ed., Aggarwal, R., Cai, Y., 1010 and T. Morin, "Extranet Multicast in BGP/IP MPLS VPNs", 1011 RFC 7900, DOI 10.17487/RFC7900, June 2016, 1012 . 1014 Authors' Addresses 1016 Eric C. Rosen (editor) 1017 Juniper Networks, Inc. 1018 10 Technology Park Drive 1019 Westford, Massachusetts 01886 1020 United States 1022 Email: erosen@juniper.net 1024 Karthik Subramanian 1025 Sproute Networks 1027 Email: karthik@sproute.com 1029 Zhaohui Zhang 1030 Juniper Networks, Inc. 1031 10 Technology Park Drive 1032 Westford, Massachusetts 01886 1033 United States 1035 Email: zzhang@juniper.net