EVPN

Ethernet Virtual Private Network (EVPN) provides a unified BGP control plane for both intra- and inter-subnet forwarding within tenant networks. When a tenant network spans multiple domains, including any combination of EVPN and IPVPN domains, it becomes necessary to define the interworking mechanisms among these BGP domains (EVPN and IPVPN) to ensure seamless end-to-end tenant connectivity. This document defines these interworking procedures.

In addition, this document defines a new BGP Path Attribute, referred to as Domain Path (D-PATH), which provides loop prevention for gateway nodes by protecting against control plane loops. The introduction of D-PATH modifies the BGP best-path selection process for Multiprotocol BGP inter-subnet forwarding (ISF) routes of Subsequent Address Family Identifiers (SAFIs) 128 (IPVPN) and 70 (EVPN).

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.

Ethernet VPN (EVPN) and Provider Backbone Bridge EVPN (PBB-EVPN) introduce a comprehensive suite of solutions for delivering Ethernet services over MPLS/IP networks. These solutions offer advanced multihoming capabilities. Specifically, they support Single-Active and All-Active redundancy modes for an Ethernet Segment (ES), which is defined as a collection of physical links connecting a multihomed device or network to a set of Provider Edge (PE) devices. This document extends the concept of an ES by allowing an ES to be associated with a set of Ethernet Virtual Circuits (EVCs), such as VLANs, or other entities, including MPLS Label Switched Paths (LSPs) or pseudowires (PWs). This extended concept is referred to as virtual Ethernet Segments (vESes). This document lists the requirements and specifies the necessary extensions to support vES in both EVPN and PBB-EVPN.

The Designated Forwarder (DF) in Ethernet Virtual Private Networks (EVPNs) is defined as the Provider Edge (PE) router responsible for sending Broadcast, Unknown Unicast, and Multicast (BUM) traffic to a multihomed device/network in the case of an All-Active multihoming Ethernet Segment (ES) or BUM and unicast in the case of Single-Active multihoming. The Designated Forwarder is selected out of a candidate list of PEs that advertise the same Ethernet Segment Identifier (ESI) to the EVPN network, according to the default DF election algorithm. While the default algorithm provides an efficient and automated way of selecting the Designated Forwarder across different Ethernet Tags in the Ethernet Segment, there are some use cases where a more "deterministic" and user-controlled method is required. At the same time, Network Operators require an easy way to force an on-demand Designated Forwarder switchover in order to carry out some maintenance tasks on the existing Designated Forwarder or control whether a new active PE can preempt the existing Designated Forwarder PE.

This document proposes use of a DF election algorithm that meets the requirements of determinism and operation control. This document updates RFC 8584 by modifying the definition of the DF Election Extended Community.

The Multi-Chassis Link Aggregation (MC-LAG) group technology enables establishing a logical link-aggregation connection with a redundant group of independent nodes. The objective of MC-LAG is to enhance both network availability and bandwidth utilization through various modes of traffic load balancing. RFC 7432 defines an EVPN-based MC-LAG with Single-Active and All-Active multihoming redundancy modes. This document builds on the existing redundancy mechanisms supported by EVPN and introduces a new active/standby redundancy mode, called 'Port-Active'.

The Ethernet Virtual Private Network (EVPN) solution in RFC 7432 provides Designated Forwarder (DF) election procedures for multihomed Ethernet Segments. These procedures have been enhanced further by applying the Highest Random Weight (HRW) algorithm for DF election to avoid unnecessary DF status changes upon a failure. This document improves these procedures by providing a fast DF election upon recovery of the failed link or node associated with the multihomed Ethernet Segment. This document updates RFC 8584 by optionally introducing delays between some of the events therein.

The solution is independent of the number of EVPN Instances (EVIs) associated with that Ethernet Segment, and it is performed via a simple signaling in BGP between the recovered node and each of the other nodes in the multihoming group.

This document specifies extensions to the Ethernet VPN Integrated Routing and Bridging (EVPN-IRB) procedures specified in RFCs 7432 and 9135 to enhance the mobility mechanisms for networks based on EVPN-IRB. The proposed extensions improve the handling of host mobility and duplicate address detection in EVPN-IRB networks to cover a broader set of scenarios where a host's unicast IP address to Media Access Control (MAC) address bindings may change across moves. These enhancements address limitations in the existing EVPN-IRB mobility procedures by providing more efficient and scalable solutions. The extensions are backward compatible with existing EVPN-IRB implementations and aim to optimize network performance in scenarios involving frequent IP address mobility.

This document describes a new EVPN Virtual Private Wire Service (VPWS) service type specifically for multiplexing multiple attachment circuits across different Ethernet Segments (ESs) and physical interfaces into a single EVPN-VPWS service tunnel and still providing Single-Active and All-Active multi-homing. This new service is referred to as the EVPN-VPWS Flexible Cross-Connect (FXC) service. This document specifies a solution based on extensions to EVPN-VPWS (RFC 8214), which in turn is based on extensions to EVPN (RFC 7432). Therefore, a thorough understanding of RFCs 7432 and 8214 are prerequisites for this document.

An Ethernet Virtual Private Network (EVPN) is commonly used with Network Virtualization Overlay (NVO) tunnels as well as with MPLS and Segment Routing (SR) tunnels. The multihoming procedures in EVPN may vary based on the type of tunnel used within the EVPN Broadcast Domain. Specifically, there are two multihoming split-horizon procedures designed to prevent looped frames on multihomed Customer Edge (CE) devices: the Ethernet Segment Identifier (ESI) Label-based procedure and the local-bias procedure. The ESI Label-based split-horizon procedure is applied to MPLS-based tunnels such as MPLS over UDP (MPLSoUDP), while the local-bias procedure is used for other tunnels such as Virtual eXtensible Local Area Network (VXLAN) tunnels.

Current specifications do not allow operators to choose which split-horizon procedure to use for tunnel encapsulations that support both methods. Examples of tunnels that may support both procedures include MPLSoUDP, MPLS over GRE (MPLSoGRE), Generic Network Virtualization Encapsulation (Geneve), and Segment Routing over IPv6 (SRv6) tunnels. This document updates the EVPN multihoming procedures described in RFCs 7432 and 8365, enabling operators to select the split-horizon procedure that meets their specific requirements.

This document specifies protocols and procedures for forwarding Broadcast, Unknown Unicast, or Multicast (BUM) traffic of Ethernet VPNs (EVPNs) using Bit Index Explicit Replication (BIER).

Ethernet VPN (EVPN) provides a service that allows a single Local Area Network (LAN), comprising a single IP subnet, to be divided into multiple segments. Each segment may be located at a different site, and the segments are interconnected by an IP or MPLS backbone. Intra-subnet traffic (either unicast or multicast) always appears to the end users to be bridged, even when it is actually carried over the IP or MPLS backbone. When a single tenant owns multiple such LANs, EVPN also allows IP unicast traffic to be routed between those LANs. This document specifies new procedures that allow inter-subnet IP multicast traffic to be routed among the LANs of a given tenant while still making intra-subnet IP multicast traffic appear to be bridged. These procedures can provide optimal routing of the inter-subnet multicast traffic and do not require any such traffic to egress a given router and then ingress that same router. These procedures also accommodate IP multicast traffic that originates or is destined to be external to the EVPN domain.

This document specifies updated procedures for handling Broadcast, Unknown Unicast, or Multicast (BUM) traffic in Ethernet VPNs (EVPNs), including selective multicast and segmentation of provider tunnels. This document updates RFC 7432.

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.

Network Virtualization Overlay (NVO) networks using Ethernet VPNs (EVPNs) as their control plane may use trees based on ingress replication or Protocol Independent Multicast (PIM) to convey the overlay Broadcast, Unknown Unicast, or Multicast (BUM) traffic. PIM provides an efficient solution that prevents sending multiple copies of the same packet over the same physical link; however, it may not always be deployed in the NVO network core. Ingress replication avoids the dependency on PIM in the NVO network core. While ingress replication provides a simple multicast transport, some NVO networks with demanding multicast applications require a more efficient solution without PIM in the core. This document describes a solution to optimize the efficiency of ingress replication trees.

Provider Backbone Bridging (PBB) can be combined with Ethernet Virtual Private Networks (EVPNs) to deploy Ethernet Local Area Network (E-LAN) services in large Multiprotocol Label Switching (MPLS) networks. That combination is what we refer to as "PBB-EVPN." Single-Active multihoming and per Service Instance Identifier (I-SID) load-balancing can be provided to access devices and aggregation networks. In order to speed up the network convergence in case of failures on Single-Active multihomed Ethernet Segments (ESs), PBB-EVPN defines a flush mechanism for Customer MACs (C-MACs) called "C-MAC flush" that works for different Ethernet Segment Backbone MAC (B-MAC) address allocation models. This document complements those C-MAC flush procedures for cases in which no PBB-EVPN ESs are defined (i.e., the attachment circuit is associated with a zero Ethernet Segment Identifier (ESI)) and the C-MAC flush requires I-SID-level granularity.

Label Switched Path (LSP) Ping is a widely deployed Operations, Administration, and Maintenance (OAM) mechanism in MPLS networks. This document describes mechanisms for detecting data plane failures using LSP Ping in MPLS-based Ethernet VPN (EVPN) and Provider Backbone Bridging EVPN (PBB-EVPN) networks.

An Ethernet Virtual Private Network (EVPN) provides a unified control plane that solves the issues of Network Virtualization Edge (NVE) auto-discovery, tenant Media Access Control (MAC) / IP dissemination, and advanced features in a scablable way as required by Network Virtualization over Layer 3 (NVO3) networks. EVPN is a scalable solution for NVO3 networks and keeps the independence of the underlay IP Fabric, i.e., there is no need to enable Protocol Independent Multicast (PIM) in the underlay network and maintain multicast states for tenant Broadcast Domains. This document describes the use of EVPN for NVO3 networks and discusses its applicability to basic Layer 2 and Layer 3 connectivity requirements and to advanced features such as MAC Mobility, MAC Protection and Loop Protection, multihoming, Data Center Interconnect (DCI), and much more. No new EVPN procedures are introduced.

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).

Ethernet VPN (EVPN) provides an extensible and flexible multihoming VPN solution over an MPLS/IP network for intra-subnet connectivity among Tenant Systems and end devices that can be physical or virtual. However, there are scenarios for which there is a need for a dynamic and efficient inter-subnet connectivity among these Tenant Systems and end devices while maintaining the multihoming capabilities of EVPN. This document describes an Integrated Routing and Bridging (IRB) solution based on EVPN to address such requirements.

The BGP MPLS-based Ethernet VPN (EVPN) (RFC 7432) mechanism provides a flexible control plane that allows intra-subnet connectivity in an MPLS and/or Network Virtualization Overlay (NVO) (RFC 7365) network. In some networks, there is also a need for dynamic and efficient inter-subnet connectivity across Tenant Systems and end devices that can be physical or virtual and do not necessarily participate in dynamic routing protocols. This document defines a new EVPN route type for the advertisement of IP prefixes and explains some use-case examples where this new route type is used.

This document specifies the requirements and reference framework for Ethernet VPN (EVPN) Operations, Administration, and Maintenance (OAM). The requirements cover the OAM aspects of EVPN and Provider Backbone Bridge EVPN (PBB-EVPN). The framework defines the layered OAM model encompassing the EVPN service layer, network layer, underlying Packet Switched Network (PSN) transport layer, and link layer but focuses on the service and network layers.

This document defines an Extended Community that is advertised along with an Ethernet Virtual Private Network (EVPN) Media Access Control (MAC) / IP Advertisement route and carries information relevant to the Address Resolution Protocol (ARP) / Neighbor Discovery (ND) resolution so that an EVPN Provider Edge (PE) implementing a proxy-ARP/ND function in broadcast domains (BDs) or an ARP/ND function on Integrated Routing and Bridging (IRB) interfaces can reply to ARP Requests or Neighbor Solicitation (NS) messages with the correct information.

This document describes how Network Virtualization Overlays (NVOs) can be connected to a Wide Area Network (WAN) in order to extend the Layer 2 connectivity required for some tenants. The solution analyzes the interaction between NVO networks running Ethernet Virtual Private Networks (EVPNs) and other Layer 2 VPN (L2VPN) technologies used in the WAN, such as Virtual Private LAN Services (VPLSs), VPLS extensions for Provider Backbone Bridging (PBB-VPLS), EVPN, or PBB-EVPN. It also describes how the existing technical specifications apply to the interconnection and extends the EVPN procedures needed in some cases. In particular, this document describes how EVPN routes are processed on Gateways (GWs) that interconnect EVPN-Overlay and EVPN-MPLS networks, as well as the Interconnect Ethernet Segment (I-ES), to provide multihoming. This document also describes the use of the Unknown MAC Route (UMR) to avoid issues of a Media Access Control (MAC) scale on Data Center Network Virtualization Edge (NVE) devices.

This document specifies mechanisms for backward compatibility of Ethernet VPN (EVPN) and Provider Backbone Bridge Ethernet VPN (PBB-EVPN) solutions with Virtual Private LAN Service (VPLS) and Provider Backbone Bridge VPLS (PBB-VPLS) solutions. It also provides mechanisms for the seamless integration of these two technologies in the same MPLS/IP network on a per-VPN-instance basis. Implementation of this document enables service providers to introduce EVPN/PBB-EVPN Provider Edges (PEs) in their brownfield deployments of VPLS/PBB-VPLS networks. This document specifies the control-plane and forwarding behavior needed for the auto-discovery of the following: 1) a VPN instance, 2) multicast and unicast operation, and 3) a Media Access Control (MAC) mobility operation. This enables seamless integration between EVPN and VPLS PEs as well as between PBB-VPLS and PBB-EVPN PEs.

An alternative to the default Designated Forwarder (DF) selection algorithm in Ethernet VPNs (EVPNs) is defined. The DF is the Provider Edge (PE) router responsible for sending Broadcast, Unknown Unicast, and Multicast (BUM) traffic to a multihomed Customer Edge (CE) device on a given VLAN on a particular Ethernet Segment (ES). In addition, the ability to influence the DF election result for a VLAN based on the state of the associated Attachment Circuit (AC) is specified. This document clarifies the DF election Finite State Machine in EVPN services. Therefore, it updates the EVPN specification (RFC 7432).

This document discusses the usage and applicability of BGP MPLS-based Ethernet VPN (EVPN) in a simple and fairly common deployment scenario. The different EVPN procedures are explained in the example scenario along with the benefits and trade-offs of each option. This document is intended to provide a simplified guide for the deployment of EVPN networks.

This document specifies how Ethernet VPN (EVPN) can be used as a Network Virtualization Overlay (NVO) solution and explores the various tunnel encapsulation options over IP and their impact on the EVPN control plane and procedures. In particular, the following encapsulation options are analyzed: Virtual Extensible LAN (VXLAN), Network Virtualization using Generic Routing Encapsulation (NVGRE), and MPLS over GRE. This specification is also applicable to Generic Network Virtualization Encapsulation (GENEVE); however, some incremental work is required, which will be covered in a separate document. This document also specifies new multihoming procedures for split-horizon filtering and mass withdrawal. It also specifies EVPN route constructions for VXLAN/NVGRE encapsulations and Autonomous System Border Router (ASBR) procedures for multihoming of Network Virtualization Edge (NVE) devices.

The MEF Forum (MEF) has defined a rooted-multipoint Ethernet service known as Ethernet-Tree (E-Tree). A solution framework for supporting this service in MPLS networks is described in RFC 7387, "A Framework for Ethernet-Tree (E-Tree) Service over a Multiprotocol Label Switching (MPLS) Network". This document discusses how those functional requirements can be met with a solution based on RFC 7432, "BGP MPLS Based Ethernet VPN (EVPN)", with some extensions and a description of how such a solution can offer a more efficient implementation of these functions than that of RFC 7796, "Ethernet-Tree (E-Tree) Support in Virtual Private LAN Service (VPLS)". This document makes use of the most significant bit of the Tunnel Type field (in the P-Multicast Service Interface (PMSI) Tunnel attribute) governed by the IANA registry created by RFC 7385; hence, it updates RFC 7385 accordingly.

This document describes how Ethernet VPN (EVPN) can be used to support the Virtual Private Wire Service (VPWS) in MPLS/IP networks. EVPN accomplishes the following for VPWS: provides Single-Active as well as All-Active multihoming with flow-based load-balancing, eliminates the need for Pseudowire (PW) signaling, and provides fast protection convergence upon node or link failure.

This document describes how Ethernet Shortest Path Bridging MAC mode (SPBM) can be combined with Ethernet VPN (EVPN) to interwork with Provider Backbone Bridging Provider Edges (PBB PEs) as described in the PBB-EVPN solution (RFC 7623). This is achieved via operational isolation of each Ethernet network attached to an EVPN core while supporting full interworking between the different variations of Ethernet networks.

This document discusses how Ethernet Provider Backbone Bridging (PBB) can be combined with Ethernet VPN (EVPN) in order to reduce the number of BGP MAC Advertisement routes by aggregating Customer/Client MAC (C-MAC) addresses via Provider Backbone MAC (B-MAC) address, provide client MAC address mobility using C-MAC aggregation, confine the scope of C-MAC learning to only active flows, offer per-site policies, and avoid C-MAC address flushing on topology changes. The combined solution is referred to as PBB-EVPN.

This document describes procedures for BGP MPLS-based Ethernet VPNs (EVPN). The procedures described here meet the requirements specified in RFC 7209 -- "Requirements for Ethernet VPN (EVPN)".

The widespread adoption of Ethernet L2VPN services and the advent of new applications for the technology (e.g., data center interconnect) have culminated in a new set of requirements that are not readily addressable by the current Virtual Private LAN Service (VPLS) solution. In particular, multihoming with all-active forwarding is not supported, and there's no existing solution to leverage Multipoint-to-Multipoint (MP2MP) Label Switched Paths (LSPs) for optimizing the delivery of multi-destination frames. Furthermore, the provisioning of VPLS, even in the context of BGP-based auto-discovery, requires network operators to specify various network parameters on top of the access configuration. This document specifies the requirements for an Ethernet VPN (EVPN) solution, which addresses the above issues.