| Internet-Draft | Multicast YANG Data Model | April 2026 |
| Zhang, et al. | Expires 15 October 2026 | [Page] |
This document provides a generic multicast YANG data model that shows the relevant technologies or protocols used by multicast flows. It provides a management view for network administrators to obtain information about multicast services.¶
This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.¶
Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.¶
Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."¶
This Internet-Draft will expire on 15 October 2026.¶
Copyright (c) 2026 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 (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License.¶
Currently, there are many multicast protocol YANG models, such as PIM (Protocol Independent Multicast), MLD (Multicast Listener Discovery), and BIER (Bit Index Explicit Replication) and so on. But all these models are distributed in different working groups as separate files and focus on the protocol itself. Furthermore, they cannot describe a high-level multicast service required by network operators.¶
This document provides a general and all-round multicast model, which shows the relevant technologies or protocols used by multicast flows. It provides a management view for network administrators to obtain information about multicast services.¶
This document does not define any specific protocol model, instead, it depends on many existing multicast protocol models and relates several multicast information together to fulfill multicast service.¶
This document defines one YANG 1.1 [RFC7950] data model for the management of multicast service. This model can be used along with other multicast YANG models such as PIM [RFC9128], which are not covered in this document.¶
The terminology for describing YANG data models is found in [RFC6020] and [RFC7950], including:¶
The following abbreviations are used in this document and the defined model:¶
BIER: Bit Index Explicit Replication [RFC8279].¶
BIER-TE: Traffic Engineering for Bit Index Explicit Replication [RFC9262].¶
MLD: Multicast Listener Discovery [I-D.ietf-bier-mld].¶
MLDP: Label Distribution Protocol Extensions for Point-to-Multipoint and Multipoint-to-Multipoint Label Switched Paths [RFC6388].¶
MVPN: Multicast in MPLS/BGP IP VPNs [RFC6513].¶
P2MP-TE: Point-to-Multipoint Traffic Engineering [RFC4875].¶
PIM: Protocol Independent Multicast [RFC7761].¶
SR-P2MP: Segment Routing Point-to-Multipoint [I-D.ietf-pim-sr-p2mp-policy].¶
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.¶
Tree diagrams used in this document follow the notation defined in [RFC8340].¶
In this document, names of data nodes, actions, and other data model objects are often used without a prefix, as long as it is clear from the context in which YANG module each name is defined. Otherwise, names are prefixed using the standard prefix associated with the corresponding YANG module, as shown in Table 1.¶
This model can be used to configure and manage the multicast service. The operational state data can be retrieved by this model. The subscription and push mechanism defined in [RFC8639] and [RFC8641] can be implemented by the user to subscribe to notifications on the data nodes in this model.¶
The model contains all the basic configuration parameters to configure the multicast service. Depending on the implementation choices, some systems may not allow some of the advanced parameters to be configurable. The occasionally implemented parameters are modeled as optional features in this model. This model can be extended, and it has been structured in a way that such extensions can be conveniently made.¶
This multicast YANG data model is mainly used by the management tools run by the network operators, in order to manage, monitor and debug the network resources that are used to deliver multicast service. This model is used for gathering data from the network as well.¶
+------------------------+
| Multicast Model |
+------------------------+
| | |
| | |
| +---------+ +----------+
| | EMS/NMS | |Controller|
| +---------+ +----------+
| | |
| | |
+------------------------------------------------+
| Network Element1.....N |
+------------------------------------------------+
Figure 1 illustrates example use cases for this multicast model. Network operators can use this model in a controller which is responsible to implement specific multicast flows with specific protocols and work with the corresponding protocols' model to configure the network elements through NETCONF/RESTCONF/CLI. Or network operators can use this model to the EMS (Element Management System)/ NMS (Network Management System) to manage or configure the network elements directly.¶
On the other hand, when the network elements detect failure or some other changes, the network devices can send the affected multicast flows and the associated signaling/ transport information to the controller. Then the controller/ EMS/NMS can respond immediately due to the failure. Such as the changing of the failure signaling protocol to another one, as well as transport protocol. Network nodes can enable appropriate signaling and transport technologies for multicast flows based on the YANG model configuration obtained from the controller. For example, the network ingress node of a multicast flow can specify its signaling protocol as MVPN and its network transport technology as BIER based on the obtained YANG model configuration. If the network ingress node does not support BIER technology, it will send a notification to the controller so that the controller can respond and adjust accordingly. Different multicast flow can use the same or different signaling and transport protocols. For the same multicast traffic, different signaling and transport technologies can also be used due to different management needs.¶
The Route Distinguisher, source-address and group-address of L3 multicast flow are the multicast flow keys. For example, when the group-address is set, and the source-address is set to * or a specific value, this is (*,G) or (S,G) analogous. In addition to the source-address and group-address, when vpn-rd is also set, this is MVPN use case. For non-VPN multicast, according to the definition in section 2.1 of RFC7716, when all RDs are set to zero, it indicates non-VPN multicast, i.e., Global Table Multicast.¶
When the ingress node of a multicast flow receives the configured YANG model, it can announce the multicast flow using the signaling protocol specified, such as MVPN. Egress nodes with receiving needs will initiate a join signaling message to the ingress node.¶
When a multicast flow's egress node receives a configured YANG model, if a signaling protocol is specified, it can initiate joining using the specified signaling protocol based on its calculated upstream multicast next hop.¶
When a transport protocol type is configured, the specified transport protocol type may be added to the signaling. For protocols that can use virtual topology for forwarding via IGP routing, such as BIER, MLDP, and PIM, when topology and flex algo number are configured, traffic will be forwarded according to the corresponding logical topology.¶
More than one ingress node for a multicast flow can be set in the model. In this situation, two or more ingress nodes are used for a multicast flow forwarding, the ingress routers can be backup for each other. More information can be found in [I-D.ietf-mboned-redundant-ingress-failover].¶
Network ingress or egress nodes can feed back the YANG model to the controller so that network administrators can check the consistency of configuration and effectiveness. When the received information is inconsistent with expectations, for example, a multicast flow should be forwarded through BIER transmission, but the received information shows that the multicast flow is forwarded by PIM, there may be some management inconsistencies.¶
This model imports and augments ietf-routing YANG model defined in [RFC8349]. The container "multicast-service" is the top-level container in this data model. The container is expected to enable multicast service functionality.¶
The YANG data model defined in this document conforms to the Network Management Datastore Architecture (NMDA) [RFC8342]. The operational state data is combined with the associated configuration data in the same hierarchy [RFC9907].¶
Tree diagrams used in this document follow the notation defined in [RFC8340].¶
The model as a whole consists of multicast flow key-value pairs, upstream and downstream information. Upstream information includes the multicast flow's ingress node in the multicast domain and the dynamic signaling protocols it may use; downstream information includes the multicast flow's egress node in the multicast domain, the dynamic signaling protocols it may use, and the transport protocols it may use. Here, the multicast domain refers to a management domain, which includes all edge nodes (ingress and egress nodes) and corresponding intermediate nodes.¶
module: ietf-multicast
+--rw multicast-service
+--rw multicast-flow* [vpn-rd source-address group-address]
+--rw vpn-rd rt-types:route-distinguisher
+--rw source-address ip-multicast-source-address
+--rw group-address rt-types:ip-multicast-group-address
+--rw upstream
| +--rw neighbor* [neighbor-address]
| +--rw neighbor-address inet:ip-address
| +--rw vni-type? identityref
| +--rw signaling? identityref
| +--rw (protocol-type)?
| +--:(evpn)
| +--:(mld)
| +--:(mld-snooping)
| +--:(mvpn)
| +--:(pim)
+--rw downstream* [signaling transport]
+--rw neighbor* [neighbor-address]
| +--rw neighbor-address inet:ip-address
+--rw signaling identityref
+--rw (protocol-type)?
| +--:(evpn)
| +--:(mld)
| +--:(mld-snooping)
| +--:(mvpn)
| +--:(pim)
+--rw transport identityref
+--rw (transport-tech-type)?
+--:(bier) {bier}?
| +--rw bier* [sub-domain]
| +--rw sub-domain uint16
| +--rw tad* [mt-id fa-number data-plane]
| | +--rw mt-id uint16
| | +--rw fa-number uint8
| | +--rw data-plane uint8
| +--rw bitstringlength? uint16
| +--rw bier-encap-type? identityref
+--:(bier-te) {bier-te}?
| +--rw bitstring* [name]
| +--rw name string
| +--rw bier-te-adj* [adj-id]
| +--rw adj-id uint16
+--:(mldp) {mldp}?
| +--rw mt-id? uint16
| +--rw fa-number? uint8
+--:(rsvp-te-p2mp) {p2mp-te}?
| +--rw tunnel-name? string
+--:(pim) {pim}?
| +--rw source-address? ip-multicast-source-address
| +--rw group-address
| | rt-types:ip-multicast-group-address
| +--rw bidir? boolean {bidir}?
| +--rw tad* [mt-id fa-number data-plane]
| +--rw mt-id uint16
| +--rw fa-number uint8
| +--rw data-plane uint8
+--:(ir-tunnel) {ir-tunnel}?
| +--rw ir-tunnel-type? uint8
+--:(sr-p2mp) {sr-p2mp}?
+--:(native)
notifications:
+---n ingress-egress-event
+--ro event-type? identityref
+--ro multicast-flow* [vpn-rd source-address group-address]
+--ro vpn-rd rt-types:route-distinguisher
+--ro source-address ip-multicast-source-address
+--ro group-address rt-types:ip-multicast-group-address
+--ro upstream
| +--ro neighbor-address? inet:ip-address
| +--ro signaling? identityref
+--ro downstream* [signaling transport]
+--ro neighbor-address? inet:ip-address
+--ro signaling identityref
+--ro transport identityref
¶
This model can work with other protocol data models to provide multicast service.¶
Based on the concept of multicast, the model includes upstream and downstream information. The content of this model includes multicast service keys, the multicast service signaling, the transport protocol information. Multicast keys include the features of multicast flow, such as (vpn-rd, multicast source and multicast group) information.¶
Multicast flows can be advertised via dynamic protocol signaling. Both ingress and egress nodes can be configured and obtain the dynamic signaling protocol types they use through the model. In certain scenarios, multicast flows can also perform tunnel encapsulation (GRE, VXLAN, etc.) before transport protocol encapsulation; the tunnel encapsulation type is included in the upstream information. Multicast flows can specify transport protocols and can further specify their associated logical topology based on topology and flex algo number; transport protocol information is included in the downstream information.¶
When a multicast flow does not need to be advertised via a dynamic signaling protocol, the addresses of all ingress and egress nodes can be directly specified in the model. When a multicast flow is advertised between ingress and egress nodes via a dynamic signaling protocol, it is not necessary to include the addresses of all ingress and egress nodes in the model; only the address of the ingress or egress node needs to be included. When a multicast flow needs to be transmitted via a specified protocol, the downstream information in the model needs to include the transmission protocol information.¶
+------------+
| +---------------------------+
+--------------+ Controller | |
| | +-----------+ |
| +------------+ | |
| | |
| +-----------------------------+ | |
| | | | |
| | +------+---+--+ |
| | |Egress router+--+ Receiver|
| | +------+------+ |
+---+-----+----+ | |
Source +-|Ingress router| BIER domain | |
+---------+----+ | |
| +------+------+ |
| |Egress router+--+ Receiver|
| +------+----+-+ |
| | | |
+-----------------------------+ +--------------+
In this example, a multicast flow using MVPN with a group address of 233.252.0.10 will be sent from one ingress node to two egress nodes within this multicast domain via BIER technology.¶
The models sent to both the ingress (upstream) and egress nodes (downstream) will contain key-value information about the flow, such as the RD and group address. The source address can be set to "*". The ingress node address is 198.51.100.10. When the ingress node receives the model, it can identify itself as upstream based on the address and configure its signaling as MVPN. The ingress node with address 198.51.100.10 will then use MVPN signaling to announce the multicast flow information.¶
The model sent to the egress nodes (198.51.100.20, 198.51.100.30) will, in addition to containing the multicast flow key, specify its downstream neighbors address. The egress nodes will recognize themselves as the egress node based on the downstream neighbor address and can then notify the upstream node of its joining information for the multicast group via MVPN signaling, specifying that traffic transmission should be via BIERin6. Furthermore, traffic transmission can be performed using a specific virtual topology, such as a virtual topology built based on the Flex Algo number 200 soft-dataplane.¶
The JSON example in the appendix can be considered a configuration example of this model. In practical applications, it is not necessary to specify both upstream and downstream information simultaneously; specifying only upstream or downstream is sufficient for it to function.¶
When there is no dynamic signaling protocol between the ingress and egress nodes, the configuration YANG model includes all ingress and egress nodes and specifies the use of the BIER transport protocol in the downstream information. Referring to the JSON example in the appendix, the signaling parameter can be removed from the upstream and downstream information.¶
Multicast model states are the same with the configuration. In most cases, network administrators can use this model to obtain multicast flows and related protocol information such as signaling protocols and transport technologies.¶
The defined Notifications include the events of ingress or egress nodes. Like ingress node failure, signaling/ transport module loading/ unloading. And the potential failure about some multicast flows and associated signaling/ transport technologies.¶
This module references [RFC4541], [RFC4875], [RFC4915], [RFC5015], [RFC5120], [RFC6388], [RFC6513], [RFC6514], [RFC7348], [RFC7432], [RFC7637], [RFC7716], [RFC7761], [RFC7988], [RFC8174], [RFC8279], [RFC8294], [RFC8296], [RFC8556], [RFC8926], [RFC9179], [RFC9262], [RFC9350], [RFC9502], [RFC9524], [RFC9572], [RFC9624], [RFC9658], [RFC9911], [I-D.ietf-bier-mld], [I-D.ietf-bier-bierin6], [I-D.ietf-bier-pim-signaling], [I-D.ietf-lsr-flex-soft-dataplane], [I-D.ietf-pim-sr-p2mp-policy], [I-D.ietf-pim-flex-algo].¶
<CODE BEGINS> file "ietf-multicast@2026-04-12.yang"
module ietf-multicast {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-multicast";
prefix ietf-multicast;
import ietf-inet-types {
prefix inet;
reference
"RFC 9911: Common YANG Data Types";
}
import ietf-routing-types {
prefix rt-types;
reference
"RFC 8294: Common YANG Data Types for the Routing Area";
}
organization
" IETF MBONED (MBONE Deployment) Working Group";
contact
"WG Web: https://datatracker.ietf.org/wg/mboned/
WG List: <mailto:mboned@ietf.org>
Editor: Zheng Zhang
<mailto:zhang.zheng@zte.com.cn>
Editor: Cui Wang
<mailto:lindawangjoy@gmail.com>
Editor: Ying Cheng
<mailto:chengying10@chinaunicom.cn>
Editor: Xufeng Liu
<mailto:xufeng.liu.ietf@gmail.com>
Editor: Mahesh Sivakumar
<mailto:sivakumar.mahesh@gmail.com>
";
// RFC Ed.: replace XXXX with actual RFC number and remove
// this note
description
"The module defines the YANG definitions for multicast service
management. This model can be used to send multicast flow
information to or retrieve multicast flow information from
devices, including upstream and downstream node information,
possible signaling protocols, and the multicast transmission
protocol that actually carries the multicast flow.
Copyright (c) 2026 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject to
the license terms contained in, the Revised BSD License set
forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX
(https://www.rfc-editor.org/info/rfcXXXX); see the RFC itself
for full legal notices.
The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL
NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'NOT RECOMMENDED',
'MAY', and 'OPTIONAL' in this document are to be interpreted as
described in BCP 14 (RFC 2119) (RFC 8174) when, and only when,
they appear in all capitals, as shown here.";
revision 2026-04-12 {
description
"Initial revision.";
reference
"RFC XXXX: A YANG Data Model for multicast service management
YANG.";
}
/*
*feature
*/
feature bier {
description
"Cooperation with BIER technology.";
reference
"RFC 8279: Multicast Using Bit Index Explicit Replication
(BIER)";
}
feature bier-te {
description
"Cooperation with BIER-TE technology.";
reference
"RFC 9262: Tree Engineering for Bit Index Explicit Replication
(BIER-TE)";
}
feature sr-p2mp {
description
"Cooperation with multipoint Segment Routing replication
technology.";
reference
"RFC 9524: Segment Routing Replication for Multipoint
Service Delivery";
}
feature ir-tunnel {
description
"Cooperation with Ingress Replication tunnel technology.";
reference
"RFC 7988: Ingress Replication Tunnels in Multicast VPN";
}
feature mldp {
description
"Cooperation with MLDP technology.";
reference
"RFC 6388: Label Distribution Protocol Extensions
for Point-to-Multipoint and Multipoint-to-Multipoint
Label Switched Paths";
}
feature p2mp-te {
description
"Cooperation with RSVP TE P2MP technology.";
reference
"RFC 4875: Extensions to Resource Reservation Protocol -
Traffic Engineering (RSVP-TE) for Point-to-Multipoint TE
Label Switched Paths (LSPs)";
}
feature pim {
description
"Cooperation with PIM technology.";
reference
"RFC 7761: Protocol Independent Multicast - Sparse Mode
(PIM-SM): Protocol Specification (Revised)";
}
feature bidir {
description
"Cooperation with BIDIR-PIM technology.";
reference
"RFC 5015: Bidirectional Protocol Independent Multicast
(BIDIR-PIM)";
}
/*
*typedef
*/
typedef ip-multicast-source-address {
type union {
type enumeration {
enum * {
description
"Any source address.";
}
}
type inet:ipv4-address;
type inet:ipv6-address;
}
description
"Multicast source IP address type.";
}
/*
* Identities
*/
identity dynamic-signaling-type {
description
"Base identity for the dynamic signaling type of multicast
service technology.";
}
identity transport-type {
description
"Identity for the multicast transport technology.";
}
identity tunnel-encap-type {
description
"Base identity for the type of multicast flow tunnel
encapsulation.";
}
identity tunnel-encap-vxlan {
base tunnel-encap-type;
description
"The VXLAN encapsulation is used for flow encapsulation.";
reference
"RFC 7348: Virtual eXtensible Local Area Network (VXLAN):
A Framework for Overlaying Virtualized Layer 2 Networks
over Layer 3 Networks";
}
identity tunnel-encap-nvgre {
base tunnel-encap-type;
description
"The NVGRE encapsulation is used for flow encapsulation.";
reference
"RFC 7637: NVGRE: Network Virtualization Using Generic
Routing Encapsulation";
}
identity tunnel-encap-geneve {
base tunnel-encap-type;
description
"The GENEVE encapsulation is used for flow encapsulation.";
reference
"RFC 8926: Geneve: Generic Network Virtualization
Encapsulation";
}
identity bier-encapsulation{
description
"Base identity for BIER encapsulation.";
}
identity bier-encap-mpls {
base bier-encapsulation;
description
"This identity represents MPLS encapsulation for bier.";
}
identity bier-encap-ipv6 {
base bier-encapsulation;
description
"This identity represents ipv6 encapsulation for bier.";
}
identity bier-encap-ethernet {
base bier-encapsulation;
description
"This identity represents ethernet encapsulation for bier.";
}
identity signaling-pim {
base dynamic-signaling-type;
description
"Using PIM as multicast service signaling technology.
This signaling protocol needs to be used in conjunction
with the transport protocol set to BIER.";
reference
"I-D.ietf-bier-pim-signaling: PIM Signaling Through BIER
Core";
}
identity mld {
base dynamic-signaling-type;
description
"Using MLD as multicast service signaling technology.
This signaling protocol needs to be used in conjunction
with the transport protocol set to BIER.";
reference
"I-D.ietf-bier-mld: BIER Ingress Multicast Flow Overlay
using Multicast Listener Discovery Protocols";
}
identity mld-snooping {
base dynamic-signaling-type;
description
"Using MLD-snooping as multicast service signaling
technology.";
reference
"RFC 4541: Considerations for Internet Group Management
Protocol (IGMP) and Multicast Listener
Discovery (MLD) Snooping Switches";
}
identity evpn {
base dynamic-signaling-type;
description
"Using EVPN as multicast service signaling technology.";
reference
"RFC 7432: BGP MPLS-Based Ethernet VPN
RFC 9572: Updates on EVPN BUM Procedures
RFC 9624: EVPN Broadcast, Unknown Unicast, or Multicast
(BUM) Using Bit Index Explicit Replication (BIER)";
}
identity mvpn {
base dynamic-signaling-type;
description
"Using MVPN as multicast service signaling technology.";
reference
"RFC 6513: Multicast in MPLS/BGP IP VPNs
RFC 7716: Global Table Multicast with BGP Multicast VPN
(BGP-MVPN) Procedures
RFC 8556: Multicast VPN Using Bit Index Explicit
Replication (BIER)";
}
identity bier {
base transport-type;
description
"Using BIER as multicast transport technology.";
reference
"RFC 8279: Multicast Using Bit Index Explicit Replication
(BIER)";
}
identity bier-te {
base transport-type;
description
"Using BIER-TE as multicast transport technology.";
reference
"RFC 9262: Traffic Engineering for Bit Index Explicit
Replication (BIER-TE)";
}
identity mldp {
base transport-type;
description
"Using mLDP as multicast transport technology.";
reference
"RFC 6388: Label Distribution Protocol Extensions
for Point-to-Multipoint and Multipoint-to-Multipoint
Label Switched Paths";
}
identity rsvp-te-p2mp {
base transport-type;
description
"Using P2MP TE as multicast transport technology.";
reference
"RFC 4875: Extensions to Resource Reservation Protocol
- Traffic Engineering (RSVP-TE) for Point-to-Multipoint
TE Label Switched Paths (LSPs)";
}
identity sr-p2mp {
base transport-type;
description
"Using Segment Routing as multicast transport technology.";
reference
"I-D.ietf-pim-sr-p2mp-policy:
Segment Routing Point-to-Multipoint Policy";
}
identity pim {
base transport-type;
description
"Using PIM as multicast transport technology.";
reference
"RFC 7761: Protocol Independent Multicast - Sparse Mode
(PIM-SM): Protocol Specification (Revised)";
}
identity bidir {
base transport-type;
description
"Using BIDIR-PIM as multicast transport technology.";
reference
"RFC 5015: Bidirectional Protocol Independent Multicast
(BIDIR-PIM)";
}
identity event-type {
description
"The events of the multicast service.";
}
identity service-up {
base event-type;
description
"The multicast service works.";
}
identity service-down {
base event-type;
description
"There is something wrong with upstream or downstream node,
and node can't work properlay.";
}
identity protocol-enabled {
base event-type;
description
"The protocol that is used for multicast flows have been
enabled.";
}
identity protocol-disabled {
base event-type;
description
"The protocol that is used by multicast flows have been
disabled.";
}
grouping general-multicast-key {
description
"The general multicast keys. They are used to differentiate
multicast service.";
leaf vpn-rd {
type rt-types:route-distinguisher;
description
"A Route Distinguisher is used to differentiate
routes from different MVPNs.
When the value is set to 0, it indicates that it is
Global Table Multicast as described in RFC7716.";
reference
"RFC 8294: Common YANG Data Types for the Routing Area
RFC 6513: Multicast in MPLS/BGP IP VPNs
RFC 7716: Global Table Multicast with BGP Multicast VPN
(BGP-MVPN) Procedures";
}
leaf source-address {
type ip-multicast-source-address;
description
"The IP source address of the multicast flow. The
value set to * means that the receiver interests
in all source that relevant to one given group.";
}
leaf group-address {
type rt-types:ip-multicast-group-address;
mandatory true;
description
"The IP group address of multicast flow. This
type represents a version-neutral IP multicast group
address. The format of the textual representation
implies the IP version.";
reference
"RFC 8294: Common YANG Data Types for the Routing Area";
}
}
// multicast-key
grouping bier-key {
description
"The key parameters set for BIER/BIER TE forwarding.";
reference
"RFC 8279: Multicast Using Bit Index Explicit Replication
(BIER).";
leaf sub-domain {
type uint16;
description
"The subdomain ID that the multicast flow belongs to.";
}
list tad {
key "mt-id fa-number data-plane";
description
"The associated Multi-Topology ID, Flex Algo number and
data plane type.";
leaf mt-id {
type uint16;
description
"The multi-topology ID that the multicast flow belongs
to.";
reference
"RFC 4915: Multi-Topology (MT) Routing in OSPF
RFC 5120: M-ISIS: Multi Topology (MT) Routing in
Intermediate System to Intermediate Systems (IS-ISs)";
}
leaf fa-number {
type uint8;
description
"Flex-algo number, value between 128 and 255 inclusive.";
reference
"RFC 9350: IGP Flexible Algorithm";
}
leaf data-plane {
type uint8;
description
"Data plane type used for prefix calculation.";
reference
"RFC 9502: IGP Flexible Algorithm in IP Networks
I-D.ietf-lsr-flex-soft-dataplane: IGP Flex Soft
Dataplane";
}
}
leaf bitstringlength {
type uint16;
description
"The bitstringlength used by BIER forwarding.";
}
leaf bier-encap-type {
type identityref {
base bier-encapsulation;
}
description
"The BIER encapsulation that can be used in either MPLS
networks or non-MPLS networks.";
}
}
grouping transport-tech {
description
"The transport technology selected for the multicast service.
For one specific multicast flow.
The same multicast flow may be forwarded using multiple
transport technologies as needed for management purposes.";
leaf transport {
type identityref {
base transport-type;
}
description
"The type of transport technology";
}
choice transport-tech-type {
description
"The type of transport technology";
case bier {
if-feature "bier";
list bier {
key "sub-domain";
description
"Using BIER as the transport technology.
The BIER technology is introduced in RFC8279.";
reference
"RFC 8296: Encapsulation for Bit Index Explicit
Replication (BIER) in MPLS and Non-MPLS Networks";
uses bier-key;
}
}
case bier-te {
if-feature "bier-te";
description
"Using BIER-TE as the transport technology.
The BIER-TE technology is introduced in RFC9262.";
reference
"RFC 9262: Tree Engineering for Bit Index Explicit
Replication (BIER-TE)";
list bitstring {
key "name";
leaf name {
type string;
description
"The name of the bitstring";
}
list bier-te-adj {
key "adj-id";
leaf adj-id {
type uint16;
description
"The link adjacency ID used for BIER TE
forwarding.";
}
description
"The adjacencies ID used for BIER TE bitstring
encapsulation.";
}
description
"The bitstring name and detail used for BIER TE
forwarding encapsulation. One or more bitstring
can be used for backup path.";
}
}
case mldp {
if-feature "mldp";
description
"Using MLDP as the transport technology.";
reference
"RFC 6388: Label Distribution Protocol Extensions
for Point-to-Multipoint and Multipoint-to-Multipoint
Label Switched Paths
RFC 9658:
Multipoint LDP Extensions for Multi-Topology Routing";
leaf mt-id {
type uint16;
description
"The multi-topology ID that the multicast flow
belongs to.";
reference
"RFC 4915: Multi-Topology (MT) Routing in OSPF
RFC 5120: M-ISIS: Multi Topology (MT) Routing in
Intermediate System to Intermediate Systems (IS-ISs)";
}
leaf fa-number {
type uint8;
description
"Flex-algo number, value between 128 and 255
inclusive.";
reference
"RFC 9350: IGP Flexible Algorithm";
}
}
case rsvp-te-p2mp {
if-feature "p2mp-te";
description
"Using RSVP TE P2MP as the transport technology.";
reference
"RFC 4875: Extensions to Resource Reservation Protocol -
Traffic Engineering (RSVP-TE) for Point-to-Multipoint
TE Label Switched Paths (LSPs)";
leaf tunnel-name {
type string;
description
"The P2MP TE tunnel name.";
}
}
case pim {
if-feature "pim";
description
"Using PIM as the transport technology.
By setting the corresponding TAD (Multi-Topology ID,
FA number, and data plane type), constraint-based
multicast path establishment can be achieved.";
reference
"RFC 7761: Protocol Independent Multicast - Sparse Mode
(PIM-SM): Protocol Specification (Revised)
I-D: ietf-pim-flex-algo: Multi-Topology in PIM";
leaf source-address {
type ip-multicast-source-address;
description
"The IP source address of the multicast flow. The
value set to * means that the receiver interests
in all source that relevant to one given group.";
}
leaf group-address {
type rt-types:ip-multicast-group-address;
mandatory true;
description
"The IP group address of multicast flow. This
type represents a version-neutral IP multicast group
address. The format of the textual representation
implies the IP version.";
}
leaf bidir {
if-feature "bidir";
type boolean;
description
"Using BIDIR-PIM as the transport technology.
When using the bidir technique, only the group address
needs to be considered.";
reference
"RFC 5015: Bidirectional Protocol Independent Multicast
(BIDIR-PIM)";
}
list tad {
key "mt-id fa-number data-plane";
description
"The Multi-Topology ID, Flex Algo number and data plane
type are used to construct the logical topology,
which enables constraint-based forwarding.";
leaf mt-id {
type uint16;
description
"The multi-topology ID.";
reference
"RFC 4915: Multi-Topology (MT) Routing in OSPF
RFC 5120: M-ISIS: Multi Topology (MT) Routing in
Intermediate System to Intermediate Systems
(IS-ISs)";
}
leaf fa-number {
type uint8;
description
"Flex-algo number, value between 128 and 255
inclusive.";
reference
"RFC 9350: IGP Flexible Algorithm";
}
leaf data-plane {
type uint8;
description
"Data plane type used for prefix calculation.";
reference
"RFC 9502: IGP Flexible Algorithm in IP Networks
I-D.ietf-lsr-flex-soft-dataplane:
IGP Flex Soft Dataplane";
}
}
}
case ir-tunnel {
if-feature "ir-tunnel";
description
"Using IR (Ingress Replication) P-tunnel for MVPN as the
transport technology.";
reference
"RFC 7988: Ingress Replication Tunnels in Multicast VPN
RFC 6514: BGP Encodings and Procedures for Multicast
in MPLS/BGP IP VPNs";
leaf ir-tunnel-type {
type uint8;
description
"The tunnel type used by MVPN ingress replication.";
}
}
case sr-p2mp {
if-feature "sr-p2mp";
description
"Using SR P2MP as the transport technology.
The ingress replication and the SR P2MP
function should not be used at the same time.";
reference
"RFC 9524: Segment Routing Replication for Multipoint
Service Delivery
I-D.ietf-pim-sr-p2mp-policy: Segment Routing
Point-to-Multipoint Policy";
}
// sr-p2mp
case native {
description
"When this type is set, it indicates that it is a
normal multicast and no additional transport
forwarding is required.";
}
}
}
// transport
/*signaling*/
grouping signaling-tech {
leaf signaling {
type identityref {
base dynamic-signaling-type;
}
description
"The type of signaling technology.";
}
choice protocol-type {
description
"The type of dynamic signaling technology.";
case evpn {
description
"EVPN technology is used for multicast service
signaling.
When BIER is used as a transport technology, there is
specific draft listed below that explain how to
perform signaling.";
reference
"RFC 7432: BGP MPLS-Based Ethernet VPN
RFC 9624: EVPN Broadcast, Unknown Unicast, or
Multicast (BUM) Using Bit Index Explicit Replication
(BIER)";
}
case mld {
description
"MLD/IGMP can be used as multicast service signaling.
When BIER is used as a transport technology, there is
specific draft listed below that explain how to
perform signaling.";
reference
"I-D:ietf-bier-mld: BIER Ingress Multicast Flow Overlay
using Multicast Listener Discovery Protocols";
}
case mld-snooping {
description
"MLD/IGMP snooping can be used as multicast service
signaling.";
reference
"RFC 4541:Considerations for Internet Group Management
Protocol (IGMP) and Multicast Listener Discovery (MLD)
Snooping Switches";
}
case mvpn {
description
"MVPN technology is used for multicast service signaling.
When BIER is used as a transport technology, there is
specific draft listed below that explain how to
perform signaling.";
reference
"RFC 6513: Multicast in MPLS/BGP IP VPNs
RFC 7716: Global Table Multicast with BGP Multicast VPN
(BGP-MVPN) Procedures
RFC 8556: Multicast VPN Using Bit Index Explicit
Replication (BIER)";
}
case pim {
description
"PIM can be used as multicast service signaling.
When BIER is used as a transport technology, there is
specific draft listed below that explain how to
perform signaling.";
reference
"RFC 7761: Protocol Independent Multicast - Sparse Mode
(PIM-SM): Protocol Specification (Revised)
I-D.ietf-bier-pim-signaling: PIM Signaling Through BIER
Core";
}
}
description
"The dynamic signaling protocols.";
}
// signaling-tech
container multicast-service {
description
"Multicast service YANG data model. Includes the flow's
key value, upstream and downstream neighbors,
and related information.";
list multicast-flow {
key "vpn-rd source-address group-address";
description
"Multicast flow information, including keys, upstream and
downstream nodes, possible signaling protocols, and
transport protocols.";
uses general-multicast-key;
container upstream {
description
"Upstream node neighbor information and the signaling
protocol used in the multicast flow.";
list neighbor {
key "neighbor-address";
description
"The IP address of the upstream node for the multicast
flow. It can be the ingress node for MVPN, EVPN, and
BIER.
In MVPN and EVPN, this is the address of the ingress
PE; in BIER, it is the BFR prefix of the BFIR.
To achieve redundant ingress node protection, two or
more ingress nodes can exist.";
leaf neighbor-address {
type inet:ip-address;
description
"The IP address of the neighbor.";
}
leaf vni-type {
type identityref {
base tunnel-encap-type;
}
description
"The encapsulated type for the multicast flow.";
}
uses signaling-tech;
}
}
// upstream
list downstream {
key "signaling transport";
description
"Downstream node neighbor information, the signaling
protocol and transport protocol used by the multicast
flow. For different downstream neighbor, different
signaling and transport technology may be used.";
list neighbor {
key "neighbor-address";
description
"The IP address of the downstream node for the multicast
flow. It can be the egress node for MVPN, EVPN, and
BIER.
In MVPN and EVPN, this is the address of the egress PE;
in BIER, it is the BFR prefix of the BFER.";
leaf neighbor-address {
type inet:ip-address;
description
"The IP address of the neighbor.";
}
}
uses signaling-tech;
uses transport-tech;
}
// downstream
}
// multicast-flow
}
/*Notifications*/
notification ingress-egress-event {
leaf event-type {
type identityref {
base event-type;
}
description
"The event type.";
}
list multicast-flow {
key "vpn-rd source-address group-address";
description
"Multicast flow information, including keys, upstream and
downstream nodes, possible signaling protocols, and
transport protocols.";
uses general-multicast-key;
container upstream {
description
"Upstream node neighbor information and the signaling
protocol used in the multicast flow.";
leaf neighbor-address {
type inet:ip-address;
description
"The IP address of the neighbor.";
}
leaf signaling {
type identityref {
base dynamic-signaling-type;
}
description
"The type of signaling technology";
}
}
// upstream
list downstream {
key "signaling transport";
description
"Downstream node neighbor information, the signaling
protocol and transport protocol used by the multicast
flow. For different downstream neighbor, different
signaling and transport technology may be used.";
leaf neighbor-address {
type inet:ip-address;
description
"The IP address of the neighbor.";
}
leaf signaling {
type identityref {
base dynamic-signaling-type;
}
description
"The type of signaling technology";
}
leaf transport {
type identityref {
base transport-type;
}
description
"The type of transport technology";
}
}
// downstream
}
// multicast-flow
description
"Notification events for the upstream or downstream nodes.
Like node failure, signaling/ transport module
loading/ unloading. And the potential failure about some
multicast flows and associated
signaling/ transport technologies.";
}
}
<CODE ENDS>¶
The "multicast-service" YANG module defines a data model that is designed to be accessed via YANG-based management protocols, such as NETCONF [RFC6241] and RESTCONF [RFC8040]. These YANG-based management protocols (1) have to use a secure transport layer (e.g., SSH [RFC4252], TLS [RFC8446], and QUIC [RFC9000]) and (2) have to use mutual authentication.¶
The Network Configuration Access Control Model (NACM) [RFC8341] provides the means to restrict access for particular Network Configuration Protocl (NETCONF) or RESTCONF users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content.¶
There are a number of data nodes defined in this YANG module that are writable/creatable/deletable (i.e., "config true", which is the default). All writable data nodes are likely to be reasonably sensitive or vulnerable in some network environments. Write operations (e.g., edit-config) and delete operations to these data nodes without proper protection or authentication can have a negative effect on network operations. The following subtrees and data nodes have particular sensitivities/vulnerabilities:¶
'upstream' and 'downstream'¶
These data nodes in this model specifies the configuration for the multicast service at the top level. Modifying the configuration can cause multicast service to be deleted or reconstructed.¶
Some of the readable data nodes in this YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control read access (e.g., via get, get-config, or notification) to these data nodes. Specifically, the following subtrees and data nodes have particular sensitivities/vulnerabilities:¶
'upstream' and 'downstream'¶
Unauthorized access to any data node of the above tree can disclose the operational state information of multicast service on this device.¶
The YANG module defines a set of identities, types, and groupings. These nodes are intended to be reused by other YANG modules. The module by itself does not expose any data nodes that are writable, data nodes that contain read-only state, or RPCs. As such, there are no additional security issues related to the YANG module that need to be considered.¶
Modules that use the groupings that are defined in this document should identify the corresponding security considerations. For example, reusing some of these groupings will expose privacy-related information (e.g., 'transport-tech').¶
RFC Ed.: Please replace all occurrences of 'XXXX' with the actual RFC number (and remove this note).¶
IANA is requested to register the following URI in the "ns" subregistry within the "IETF XML Registry" [RFC3688]:¶
URI: urn:ietf:params:xml:ns:yang:ietf-multicast¶
Registrant Contact: The IESG¶
XML: N/A, the requested URI is an XML namespace.¶
IANA is requested to register the following YANG module in the "YANG Module Names" subregistry [RFC6020] within the "YANG Parameters" registry.¶
name: ietf-multicast¶
Maintained by IANA? N¶
namespace: urn:ietf:params:xml:ns:yang:ietf-multicast¶
prefix: ietf-multicast¶
reference: RFC XXXX¶
The authors would like to thank Stig Venaas, Jake Holland, Min Gu, Gyan Mishra, Jeffrey Zhang for their valuable comments and suggestions.¶
This section contains an example of an instance data tree in JSON encoding [RFC7951], containing configuration data.¶
The configuration example:¶
{
"ietf-multicast:multicast-service":{
"multicast-flow":[
{
"vpn-rd":"0:65532:4294967292",
"source-address":"*",
"group-address":"233.252.0.10",
"upstream":{
"neighbor":[
{
"neighbor-address":"198.51.100.10",
"vni-type":"tunnel-encap-vxlan",
"signaling":"mvpn"
}
]
}
},
{
"vpn-rd":"0:65532:4294967292",
"source-address":"*",
"group-address":"233.252.0.11",
"downstream":[
{
"signaling":"mvpn",
"transport":"bier",
"neighbor":[
{
"neighbor-address":"198.51.100.20"
},
{
"neighbor-address":"198.51.100.30"
}
],
"bier":[
{
"sub-domain":1,
"tad":[
{
"mt-id":0,
"fa-number":200,
"data-plane":3
}
],
"bier-encap-type":"bier-encap-ipv6"
}
]
}
]
}
]
}
}
¶