MVPN

A Point-to-Multipoint (P2MP) tree in a Segment Routing (SR) domain carries traffic from a Root to a set of Leaves. This document specifies extensions to BGP encodings and procedures for P2MP trees and Ingress Replication used in BGP/MPLS IP VPNs and Ethernet VPNs (EVPNs) in an SR domain. This document updates RFCs 6514 and 7988.

In Ethernet Virtual Private Networks (EVPNs), IP multicast traffic replication and delivery play a crucial role in enabling efficient and scalable Layer 2 and Layer 3 services. A common deployment scenario involves redundant multicast sources that ensure high availability and resiliency. However, the presence of redundant sources can lead to duplicate IP multicast traffic in the network, causing inefficiencies and increased overhead. This document specifies extensions to the EVPN multicast procedures that allow for the suppression of duplicate IP multicast traffic from redundant sources. The proposed mechanisms enhance the EVPN's capability to deliver multicast traffic efficiently while maintaining high availability. These extensions are applicable to various EVPN deployment scenarios and provide guidelines to ensure consistent and predictable behavior across diverse network topologies.

The Multicast VPN (MVPN) specifications allow a single Point-to-Multipoint (P2MP) tunnel to carry traffic of multiple IP VPNs (referred to as VPNs in this document). The EVPN specifications allow a single P2MP tunnel to carry traffic of multiple Broadcast Domains (BDs). These features require the ingress router of the P2MP tunnel to allocate an upstream-assigned MPLS label for each VPN or for each BD. A packet sent on a P2MP tunnel then carries the label that is mapped to its VPN or BD (in some cases, a distinct upstream-assigned label is needed for each flow.) Since each ingress router allocates labels independently, with no coordination among the ingress routers, the egress routers may need to keep track of a large number of labels. The number of labels may need to be as large as, or larger than, the product of the number of ingress routers times the number of VPNs or BDs. However, the number of labels can be greatly reduced if the association between a label and a VPN or BD is made by provisioning, so that all ingress routers assign the same label to a particular VPN or BD. New procedures are needed in order to take advantage of such provisioned labels. These new procedures also apply to Multipoint-to-Multipoint (MP2MP) tunnels. This document updates RFCs 6514, 7432, and 7582 by specifying the necessary procedures.

This document describes how to support endpoints running the Internet Group Management Protocol (IGMP) or Multicast Listener Discovery (MLD) efficiently for the multicast services over an Ethernet VPN (EVPN) network by incorporating IGMP/MLD Proxy procedures on EVPN Provider Edges (PEs).

This document specifies the procedures for interoperation between Multicast Virtual Private Network (MVPN) Source-Active (SA) routes and customer Multicast Source Discovery Protocol (MSDP) SA routes, which is useful for MVPN provider networks offering services to customers with an existing MSDP infrastructure. Without the procedures described in this document, VPN-specific MSDP sessions are required among the Provider Edge (PE) routers that are customer MSDP peers. This document updates RFC 6514.

This document defines Multicast Virtual Private Network (VPN) extensions and procedures that allow fast failover for upstream failures by allowing downstream Provider Edges (PEs) to consider the status of Provider-Tunnels (P-tunnels) when selecting the Upstream PE for a VPN multicast flow. The fast failover is enabled by using "Bidirectional Forwarding Detection (BFD) for Multipoint Networks" (RFC 8562) and the new BGP Attribute, BFD Discriminator. Also, this document introduces a new BGP Community, Standby PE, extending BGP Multicast VPN (MVPN) routing so that a C-multicast route can be advertised toward a Standby Upstream PE.

Multiprotocol BGP (MP-BGP) specifies that the set of usable next-hop address families is determined by the Address Family Identifier (AFI) and the Subsequent Address Family Identifier (SAFI). The AFI/SAFI definitions for the IPv4 address family only have provisions for advertising a next-hop address that belongs to the IPv4 protocol when advertising IPv4 Network Layer Reachability Information (NLRI) or VPN-IPv4 NLRI.

This document specifies the extensions necessary to allow the advertising of IPv4 NLRI or VPN-IPv4 NLRI with a next-hop address that belongs to the IPv6 protocol. This comprises an extension of the AFI/SAFI definitions to allow the address of the next hop for IPv4 NLRI or VPN-IPv4 NLRI to also belong to the IPv6 protocol, the encoding of the next hop to determine which of the protocols the address actually belongs to, and a BGP Capability allowing MP-BGP peers to dynamically discover whether they can exchange IPv4 NLRI and VPN-IPv4 NLRI with an IPv6 next hop. This document obsoletes RFC 5549.

The Multicast Virtual Private Network (MVPN) specifications require the use of multicast tunnels ("P-tunnels") that traverse a service provider's backbone network. The P-tunnels are used for carrying multicast traffic across the backbone. A variety of P-tunnel types are supported. Bit Index Explicit Replication (BIER) is a new architecture that provides optimal multicast forwarding through a "multicast domain", without requiring intermediate routers to maintain any per-flow state or to engage in an explicit tree-building protocol. This document specifies the protocol and procedures that allow MVPN to use BIER as the method of carrying multicast traffic over a service provider's backbone network.

The base Multicast VPN (MVPN) specifications (RFCs 6513 and 6514) provide procedures to allow a multicast ingress node to invoke "explicit tracking" for a multicast flow or set of flows, thus learning the egress nodes for that flow or set of flows. However, the specifications are not completely clear about how the explicit tracking procedures work in certain scenarios. This document provides the necessary clarifications. It also specifies a new, optimized explicit-tracking procedure. This new procedure allows an ingress node, by sending a single message, to request explicit tracking of each of a set of flows, where the set of flows is specified using a wildcard mechanism. This document updates RFCs 6514, 6625, 7524, 7582, and 7900.

This memo defines a portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. In particular, it describes two MIB modules that will be used by other MIB modules for monitoring and/or configuring Layer 2 and Layer 3 Virtual Private Networks that support multicast.

This memo defines a portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. In particular, it describes managed objects to configure and/or monitor Multicast communication over IP Virtual Private Networks (VPNs) supported by the Multiprotocol Label Switching/Border Gateway Protocol (MPLS/BGP) on a Provider Edge (PE) router.

RFCs 6513, 6514, and other RFCs describe procedures by which a Service Provider may offer Multicast VPN (MVPN) service to its customers. These procedures create point-to-multipoint (P2MP) or multipoint-to-multipoint (MP2MP) trees across the Service Provider's backbone. One type of P2MP tree that may be used is known as an "Ingress Replication (IR) tunnel". In an IR tunnel, a parent node need not be directly connected to its child nodes. When a parent node has to send a multicast data packet to its n child nodes, it does not use Layer 2 multicast, IP multicast, or MPLS multicast to do so. Rather, it makes n individual copies, and then unicasts each copy, through an IP or MPLS unicast tunnel, to exactly one child node. While the prior MVPN specifications allow the use of IR tunnels, those specifications are not always very clear or explicit about how the MVPN protocol elements and procedures are applied to IR tunnels. This document updates RFCs 6513 and 6514 by adding additional details that are specific to the use of IR tunnels.

This document describes procedures to damp Multicast VPN (MVPN) routing state changes and control the effect of the churn due to the multicast dynamicity in customer sites. The procedures described in this document are applicable to BGP-based multicast VPN and help avoid uncontrolled control-plane load increase in the core routing infrastructure. The new procedures proposed were inspired by BGP unicast route damping principles that have been adapted to multicast.

Previous RFCs specify the procedures necessary to allow IP multicast traffic to travel from one site to another within a BGP/MPLS IP VPN (Virtual Private Network). However, it is sometimes desirable to allow multicast traffic whose source is in one VPN to be received by systems that are in another VPN. This is known as a "Multicast VPN (MVPN) extranet". This document updates RFCs 6513, 6514, and 6625 by specifying the procedures that are necessary in order to provide extranet MVPN service.

RFC 6513 ("Multicast in MPLS/BGP IP VPNs") describes a method to support bidirectional customer multicast flows using a partial mesh of Multipoint-to-Multipoint (MP2MP) tunnels. This document specifies how a partial mesh of MP2MP tunnels can be simulated using Ingress Replication. This solution enables a service provider to use Ingress Replication to offer transparent bidirectional multicast service to its VPN customers.

RFCs 6513, 6514, and others describe protocols and procedures that a Service Provider (SP) may deploy in order to offer Multicast Virtual Private Network (Multicast VPN or MVPN) service to its customers. Some of these procedures use BGP to distribute VPN-specific multicast routing information across a backbone network. With a small number of relatively minor modifications, the same BGP procedures can also be used to distribute multicast routing information that is not specific to any VPN. Multicast that is outside the context of a VPN is known as "Global Table Multicast", or sometimes simply as "Internet multicast". In this document, we describe the modifications that are needed to use the BGP-MVPN procedures for Global Table Multicast.

A set of prior RFCs specify procedures for supporting multicast in BGP/MPLS IP VPNs. These procedures allow customer multicast data to travel across a service provider's backbone network through a set of multicast tunnels. The tunnels are advertised in certain BGP multicast auto-discovery routes, by means of a BGP attribute known as the "Provider Multicast Service Interface (PMSI) Tunnel" attribute. Encodings have been defined that allow the PMSI Tunnel attribute to identify bidirectional (multipoint-to-multipoint) multicast distribution trees. However, the prior RFCs do not provide all the necessary procedures for using bidirectional tunnels to support multicast VPNs. This document updates RFCs 6513, 6514, and 6625 by specifying those procedures. In particular, it specifies the procedures for assigning customer multicast flows (unidirectional or bidirectional) to specific bidirectional tunnels in the provider backbone, for advertising such assignments, and for determining which flows have been assigned to which tunnels.

In Multicast Virtual Private Networks (MVPNs), customer multicast flows are carried in "tunnels" through a service provider's network. The base specifications for MVPN define BGP multicast VPN "auto-discovery routes" and specify how to use an auto-discovery route to advertise the fact that an individual customer multicast flow is being carried in a particular tunnel. However, those specifications do not provide a way to specify, in a single such route, that multiple customer flows are being carried in a single tunnel. Those specifications also do not provide a way to advertise that a particular tunnel is to be used by default to carry all customer flows, except in the case where that tunnel is joined by all the provider edge routers of the MVPN. This document eliminates these restrictions by specifying the use of "wildcard" elements in the customer flow identifiers. With wildcard elements, a single auto-discovery route can refer to multiple customer flows or even to all customer flows. [STANDARDS-TRACK]

In order for IP multicast traffic within a BGP/MPLS IP VPN (Virtual Private Network) to travel from one VPN site to another, special protocols and procedures must be implemented by the VPN Service Provider. These protocols and procedures are specified in this document. [STANDARDS-TRACK]

This document describes the BGP encodings and procedures for exchanging the information elements required by Multicast in MPLS/BGP IP VPNs, as specified in RFC 6513. [STANDARDS-TRACK]

To provide Multicast VPN (MVPN) service, Provider Edge routers originate BGP Update messages that carry Multicast-VPN ("MCAST-VPN") BGP routes; they also originate unicast VPN routes that carry MVPN-specific attributes. These routes encode addresses from the customer's address space, as well as addresses from the provider's address space. These two address spaces are independent, and the address family (IPv4 or IPv6) of the two spaces may or may not be the same. These routes always contain an "address family" field that specifies whether the customer addresses are IPv4 addresses or whether they are IPv6 addresses. However, there is no field that explicitly specifies the address family of the provider addresses. To ensure interoperability, this document specifies that provider IPv4 addresses are always encoded in these update messages as 4-octet addresses, and that the distinction between IPv4 and IPv6 is signaled solely by the length of the address field. Specific cases are explained in detail. This document updates RFC 6514. [STANDARDS-TRACK]

The specification for Multicast Virtual Private Networks (MVPNs) contains an option that allows the use of PIM as the control protocol between provider edge routers. It also contains an option that allows UDP-based messages, known as Selective Provider Multicast Service Interface (S-PMSI) Join messages, to be used to bind particular customer multicast flows to particular tunnels through a service provider's network. This document extends the MVPN specification (RFC 6513) so that these options can be used when the customer multicast flows are IPv6 flows. [STANDARDS-TRACK]

More that one set of mechanisms to support multicast in a layer 3 BGP/MPLS VPN has been defined. These are presented in the documents that define them as optional building blocks.

To enable interoperability between implementations, this document defines a subset of features that is considered mandatory for a multicast BGP/MPLS VPN implementation. This will help implementers and deployers understand which L3VPN multicast requirements are best satisfied by each option. This document is not an Internet Standards Track specification; it is published for informational purposes.

This document describes the MVPN (Multicast in BGP/MPLS IP VPNs) solution designed and deployed by Cisco Systems. The procedures specified in this document are largely a subset of the generalized MVPN framework recently standardized by the IETF. However, as the deployment of the procedures specified herein predates the publication of IETF standards (in some cases by over five years), an implementation based on these procedures differs in some respects from a fully standards-compliant implementation. These differences are pointed out in the document. This document defines a Historic Document for the Internet community.

This document provides functional requirements for network solutions that support multicast over Virtual Private LAN Service (VPLS). It specifies requirements both from the end user and service provider standpoints. It is intended that potential solutions will use these requirements as guidelines. This memo provides information for the Internet community.

This document presents a set of functional requirements for network solutions that allow the deployment of IP multicast within Layer 3 (L3) Provider-Provisioned Virtual Private Networks (PPVPNs). It specifies requirements both from the end user and service provider standpoints. It is intended that potential solutions specifying the support of IP multicast within such VPNs will use these requirements as guidelines. This memo provides information for the Internet community.