BGP Enabled ServiceS (bess) Internet Drafts


      
 BGP based Multi-homing in Virtual Private LAN Service
 
 draft-ietf-bess-vpls-multihoming-06.txt
 Date: 16/06/2025
 Authors: Kireeti Kompella, Bhupesh Kothari, Wim Henderickx, Florin Balus, Jim Uttaro
 Working Group: BGP Enabled ServiceS (bess)
Virtual Private LAN Service (VPLS) is a Layer 2 Virtual Private Network (VPN) that gives its customers the appearance that their sites are connected via a Local Area Network (LAN). It is often required for the Service Provider (SP) to give the customer redundant connectivity to some sites, often called "multi-homing". This memo shows how BGP-based multi-homing can be offered in the context of LDP and BGP VPLS solutions. This document updates RFC 4761 by defining new flags in the Control Flags field of the Layer2 Info Extended Community.
 Per multicast flow Designated Forwarder Election for EVPN
 
 draft-ietf-bess-evpn-per-mcast-flow-df-election-12.txt
 Date: 07/07/2025
 Authors: Ali Sajassi, Mankamana Mishra, Samir Thoria, Jorge Rabadan, John Drake
 Working Group: BGP Enabled ServiceS (bess)
This document defines an enhancement to the Designated Forwarder (DF) election process in Ethernet Virtual Private Network (EVPN) environments. While traditional DF election operates at a per Virtual Local Area Network (VLAN) or per group of VLANs (in case of VLAN bundle or VLAN-aware bundle service) level, such granularity may not be sufficient for applications requiring optimized or isolated multicast forwarding. This specification introduces a refined DF election mechanism that extends existing hash-based methods to operate at a more granular level specifically at the tuple of Ethernet Segment Identifier (ESI), VLAN, and multicast flow. This approach enables improved traffic distribution, enhanced load balancing, and greater deployment flexibility for multicast delivery in EVPN based networks. The proposed method is designed to remain compatible with existing DF election procedures while offering targeted improvements for multicast scenarios.
 Weighted Multi-Path Procedures for EVPN Multi-Homing
 
 draft-ietf-bess-evpn-unequal-lb-26.txt
 Date: 05/07/2025
 Authors: Neeraj Malhotra, Ali Sajassi, Jorge Rabadan, John Drake, Avinash Lingala, Samir Thoria
 Working Group: BGP Enabled ServiceS (bess)
EVPN enables all-active multi-homing for a CE (Customer Equipment) device connected to two or more PE (Provider Equipment) devices via a LAG (Link Aggregation), such that bridged and routed traffic from remote PEs to hosts attached to the Ethernet Segment can be equally load balanced (it uses Equal Cost Multi Path) across the multi-homing PEs. EVPN also enables multi-homing for IP subnets advertised in IP Prefix routes, so that routed traffic from remote PEs to those IP subnets can be load balanced. This document defines extensions to EVPN procedures to optimally handle unequal access bandwidth distribution across a set of multi-homing PEs in order to: * provide greater flexibility, with respect to adding or removing individual multi-homed PE-CE links. * handle multi-homed PE-CE link failures that can result in unequal PE-CE access bandwidth across a set of multi-homing PEs. In order to achieve the above, it specifies signaling extensions and procedures to: * Loadbalance bridged and routed traffic across egress PEs in proportion to PE-CE link bandwidth or a generalized weight distribution. * Achieve BUM (Broadcast, UnknownUnicast, Multicast) DF (Designated Forwarder) election distribution for a given ES (Ethernet Segment) across the multi-homing PE set in proportion to PE-CE link bandwidth. Section 6 of this document further updates RFC 8584, draft-ietf-bess-evpn-per-mcast-flow-df-election and draft-ietf- bess-evpn-pref-df in order for the DF election extension defined in this document to work across different DF election algorithms.
 EVPN Interworking with IPVPN
 
 draft-ietf-bess-evpn-ipvpn-interworking-14.txt
 Date: 18/06/2025
 Authors: Jorge Rabadan, Ali Sajassi, Eric Rosen, John Drake, Wen Lin, Jim Uttaro, Adam Simpson
 Working Group: BGP Enabled ServiceS (bess)
Ethernet Virtual Private Network (EVPN) is used as a unified control plane for tenant network intra and inter-subnet forwarding. When a tenant network spans not only EVPN domains but also domains where BGP VPN-IP or IP families provide inter-subnet forwarding, there is a need to specify the interworking aspects between BGP domains of type EVPN, VPN-IP and IP, so that the end-to-end tenant connectivity can be accomplished. This document specifies how EVPN interworks with VPN-IPv4/VPN-IPv6 and IPv4/IPv6 BGP families for inter-subnet forwarding. The document also addresses the interconnect of EVPN domains for Inter-Subnet Forwarding routes. In addition, this specification defines a new BGP Path Attribute called D-PATH (Domain PATH) that protects gateways against control plane loops. D-PATH modifies the BGP best path selection for multiprotocol BGP routes of SAFI 128 and EVPN IP Prefix routes, and therefore this document updates the BGP best path selection specification, but only for IPVPN and EVPN families.
 Seamless Multicast Interoperability between EVPN and MVPN PEs
 
 draft-ietf-bess-evpn-mvpn-seamless-interop-08.txt
 Date: 02/03/2025
 Authors: Ali Sajassi, Kesavan Thiruvenkatasamy, Samir Thoria, Ashutosh Gupta, Luay Jalil
 Working Group: BGP Enabled ServiceS (bess)
Ethernet Virtual Private Network (EVPN) solution is becoming pervasive for Network Virtualization Overlay (NVO) services in data center (DC), Enterprise networks as well as in service provider (SP) networks. As service providers transform their networks in their Central Offices (COs) towards the next generation data center with Software Defined Networking (SDN) based fabric and Network Function Virtualization (NFV), they want to be able to maintain their offered services including Multicast VPN (MVPN) service between their existing network and their new Service Provider Data Center (SPDC) network seamlessly without the use of gateway devices. They want to have such seamless interoperability between their new SPDCs and their existing networks for a) reducing cost, b) having optimum forwarding, and c) reducing provisioning. This document describes a unified solution based on RFCs 6513 & 6514 for seamless interoperability of Multicast VPN between EVPN and MVPN PEs. Furthermore, it describes how the proposed solution can be used as a routed multicast solution in data centers with only EVPN PEs.
 Controller-based BGP Multicast Signaling
 
 draft-ietf-bess-bgp-multicast-controller-16.txt
 Date: 28/02/2025
 Authors: Zhaohui Zhang, RASZUK Robert, Dante Pacella, Arkadiy Gulko
 Working Group: BGP Enabled ServiceS (bess)
This document specifies a way that one or more centralized controllers can use BGP to set up multicast distribution trees (identified by either IP source/destination address pair, or mLDP FEC) in a network. Since the controllers calculate the trees, they can use sophisticated algorithms and constraints to achieve traffic engineering. The controllers directly signal dynamic replication state to tree nodes, leading to very simple multicast control plane on the tree nodes, as if they were using static routes. This can be used for both underlay and overlay multicast trees, including replacing BGP-MVPN signaling.
 BGP Based Multicast
 
 draft-ietf-bess-bgp-multicast-09.txt
 Date: 24/07/2025
 Authors: Zhaohui Zhang, Lenny Giuliano, Keyur Patel, IJsbrand Wijnands, Mankamana Mishra, Arkadiy Gulko
 Working Group: BGP Enabled ServiceS (bess)
This document specifies a BGP address family and related procedures that allow BGP to be used for setting up multicast distribution trees. This document also specifies procedures that enable BGP to be used for multicast source discovery, and for showing interest in receiving particular multicast flows. Taken together, these procedures allow BGP to be used as a replacement for other multicast routing protocols, such as PIM or mLDP. The BGP procedures specified here are based on the BGP multicast procedures that were originally designed for use by providers of Multicast Virtual Private Network service. This document also describes how various signaling mechanisms can be used to set up end-to-end inter-region multicast trees.
 EVPN Network Layer Fault Management
 
 draft-ietf-bess-evpn-bfd-10.txt
 Date: 22/04/2025
 Authors: Vengada Govindan, Mallik Mudigonda, Ali Sajassi, Greg Mirsky, Donald Eastlake
 Working Group: BGP Enabled ServiceS (bess)
This document specifies proactive, in-band network layer OAM (RFC 9062) mechanisms to detect loss of continuity faults that affect unicast and multi-destination paths (used by Broadcast, Unknown Unicast, and Multicast traffic) in an Ethernet VPN (EVPN, RFC 7432bis) network. The mechanisms specified in this document use the widely adopted Bidirectional Forwarding Detection (RFC 5880) protocol.
 BGP Usage for SD-WAN Overlay Networks
 
 draft-ietf-bess-bgp-sdwan-usage-26.txt
 Date: 28/07/2025
 Authors: Linda Dunbar, Ali Sajassi, John Drake, Basil Najem, Sue Hares
 Working Group: BGP Enabled ServiceS (bess)
This document explores the complexities involved in managing large scale Software Defined WAN (SD-WAN) overlay networks, along with various SD-WAN scenarios. Its objective is to illustrate how a BGP-based control plane can effectively manage these overlay networks by distributing edge service reachability information, WAN port attributes, and underlay path details, thereby minimizing manual provisioning.
 Multicast and Ethernet VPN with Segment Routing P2MP and Ingress Replication
 
 draft-ietf-bess-mvpn-evpn-sr-p2mp-14.txt
 Date: 07/07/2025
 Authors: Rishabh Parekh, Dan Voyer, Clarence Filsfils, Mankamana Mishra, Hooman Bidgoli, Zhaohui Zhang
 Working Group: BGP Enabled ServiceS (bess)
A Point-to-Multipoint (P2MP) Tree in a Segment Routing domain carries traffic from a Root to a set of Leaves. This document describes extensions to BGP encodings and procedures for P2MP trees and Ingress Replication used in BGP/MPLS IP VPNs and Ethernet VPNs in a Segment Routing domain.
 BGP MPLS-Based Ethernet VPN
 
 draft-ietf-bess-rfc7432bis-13.txt
 Date: 24/06/2025
 Authors: Ali Sajassi, Luc Burdet, John Drake, Jorge Rabadan
 Working Group: BGP Enabled ServiceS (bess)
This document describes procedures for Ethernet VPN (EVPN), a BGP MPLS-based solution which addresses the requirements specified in the corresponding RFC - "Requirements for Ethernet VPN (EVPN)". This document obsoletes RFC7432 (BGP MPLS-Based Ethernet VPN) and updates RFC8214 (Virtual Private Wire Service Support in Ethernet VPN).
 Multicast Source Redundancy in EVPN Networks
 
 draft-ietf-bess-evpn-redundant-mcast-source-15.txt
 Date: 14/02/2025
 Authors: Jorge Rabadan, Jayant Kotalwar, Senthil Sathappan, Zhaohui Zhang, Wen Lin
 Working Group: BGP Enabled ServiceS (bess)
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 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.
 EVPN Multi-Homing Mechanism for Layer-2 Gateway Protocols
 
 draft-ietf-bess-evpn-l2gw-proto-05.txt
 Date: 03/03/2025
 Authors: Luc Burdet, Patrice Brissette, Ali Sajassi, Praveen Maheshwari, Ishan Bhatt
 Working Group: BGP Enabled ServiceS (bess)
The existing EVPN multi-homing load-balancing modes do not adequately represent ethernet-segments facing access networks with Layer-2 Gateway protocols such as G.8032, (M)STP, etc. This document defines a new multi-homing mechanism to support these loop-preventing Layer-2 protocols.
 Cumulative DMZ Link Bandwidth and load-balancing
 
 draft-ietf-bess-ebgp-dmz-07.txt
 Date: 20/07/2025
 Authors: MOHANTY Satya, Arie Vayner, Akshay Gattani, Ajay Kini, Jeff Tantsura, Reshma Das
 Working Group: BGP Enabled ServiceS (bess)
The DMZ Link Bandwidth draft provides a way to load-balance traffic to a destination which is reachable via more than one path according to the weight attahced. Typically, the link bandwidth (either configured on the link of the EBGP egress interface or set via a policy) is encoded in an extended community and then sent to the IBGP peer that employs multi-path. The link-bandwidth value is then extracted from the extended community and is used as a weight in the RIB/FIB, which does the load-balancing. This draft extends the usage of the DMZ link bandwidth to another setting where the ingress BGP speaker requires knowledge of the cumulative bandwidth while doing the load-balancing. The draft also proposes neighbor-level knobs to enable the link bandwidth extended community to be regenerated and then advertised to EBGP peers to override the default behavior of not advertising optional non-transitive attributes to EBGP peers.
 AC-Aware Bundling Service Interface in EVPN
 
 draft-ietf-bess-evpn-ac-aware-bundling-05.txt
 Date: 07/07/2025
 Authors: Ali Sajassi, Luc Burdet, Mankamana Mishra, Jorge Rabadan, John Drake
 Working Group: BGP Enabled ServiceS (bess)
An EVPN (Ethernet VPNs) 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. EVPN multihoming with Integrated Routing and Bridging (IRB) is one of the common deployment scenarios. Some deployments requires the capability to have multiple subnets designated with multiple VLAN IDs in the single broadcast domain. EVPN technology defines three different types of service interface which serve different requirements but none of them address the requirement of supporting multiple subnets within a single broadcast domain. In this document, we define a new service interface type to support multiple subnets in the single broadcast domain. Service interface proposed in this document will be applicable to multihoming cases only.
 Weighted HRW and its applications
 
 draft-ietf-bess-weighted-hrw-02.txt
 Date: 07/07/2025
 Authors: MOHANTY Satya, Mankamana Mishra, Acee Lindem, Ali Sajassi, John Drake
 Working Group: BGP Enabled ServiceS (bess)
Rendezvous Hashing also known as Highest Random Weight (HRW) has been used in many load balancing applications where the central problem is how to map an object to as server such that the mapping is uniform and also minimally affected by the change in the server set. Recently, it has found use in DF election algorithms in the EVPN context and load balancing using DMZ. This draft deals with the problem of achieving load balancing with minimal disruption when the servers have different weights. It provides an algorithm to do so and also describes a few use-case scenarios where this algorithmic technique can apply.
 EVPN-VPWS Seamless Integration with L2VPN VPWS
 
 draft-ietf-bess-evpn-vpws-seamless-02.txt
 Date: 09/05/2025
 Authors: Patrice Brissette, Wen Lin, Jorge Rabadan, Jim Uttaro, Bin Wen
 Working Group: BGP Enabled ServiceS (bess)
This document presents a solution for migrating L2VPN Virtual Private Wire Service (VPWS) to Ethernet VPN Virtual Private Wire Service (EVPN-VPWS) services. The solution allows the coexistence of EVPN and L2VPN services under the same point-to-point VPN instance. By using this seamless integration solution, a service provider can introduce EVPN into their existing L2VPN network or migrate from an existing L2VPN based network to EVPN. The migration may be done per pseudowire or per flexible-crossconnect (FXC) service basis. This document specifies control-plane and forwarding behaviors.
 EVPN Support for L3 Fast Convergence and Aliasing/Backup Path
 
 draft-ietf-bess-evpn-ip-aliasing-03.txt
 Date: 07/05/2025
 Authors: Ali Sajassi, Jorge Rabadan, S. Pasupula, Lukas Krattiger, John Drake
 Working Group: BGP Enabled ServiceS (bess)
This document proposes an EVPN extension to allow several of its multi-homing functions, fast convergence, and aliasing/backup path, to be used in conjunction with inter-subnet forwarding. The extension is limited to All-Active and Single-Active redundancy modes.
 Domain Path (D-PATH) for Ethernet VPN (EVPN) Interconnect Networks
 
 draft-ietf-bess-evpn-dpath-02.txt
 Date: 03/03/2025
 Authors: Jorge Rabadan, Senthil Sathappan, Mallika Gautam, Patrice Brissette, Wen Lin
 Working Group: BGP Enabled ServiceS (bess)
The BGP Domain PATH (D-PATH) attribute is defined for Inter-Subnet Forwarding (ISF) BGP Sub-Address Families that advertise IP prefixes. When used along with EVPN IP Prefix routes or IP-VPN routes, it identifies the domain(s) through which the routes have passed and that information can be used by the receiver BGP speakers to detect routing loops or influence the BGP best path selection. This document extends the use of D-PATH so that it can also be used along with other EVPN route types.
 Ethernet VPN Virtual Private Wire Services Gateway Solution
 
 draft-ietf-bess-evpn-vpws-gateway-00.txt
 Date: 19/05/2025
 Authors: Jorge Rabadan, Senthil Sathappan, Vinod Prabhu, Wen Lin, Patrice Brissette
 Working Group: BGP Enabled ServiceS (bess)
Ethernet Virtual Private Network Virtual Private Wire Services (EVPN VPWS) need to be deployed in high scale multi-domain networks, where each domain can use a different transport technology, such as MPLS, VXLAN or Segment Routing with MPLS or IPv6 Segment Identifiers (SIDs). While transport interworking solutions on border routers spare the border routers from having to process service routes, they do not always meet the multi-homing, redundancy, and operational requirements, or provide the isolation that each domain requires. This document analyzes the scenarios in which an interconnect solution for EVPN VPWS using EVPN Domain Gateways is needed, and adds the required extensions to support it.
 EVPN Fast Reroute
 
 draft-ietf-bess-evpn-fast-reroute-00.txt
 Date: 09/06/2025
 Authors: Luc Burdet, Patrice Brissette, Takuya Miyasaka, Jorge Rabadan, Yisong Liu, Changwang Lin
 Working Group: BGP Enabled ServiceS (bess)
This document summarises EVPN convergence mechanisms and specifies procedures for EVPN networks to achieve fast and scale-independent convergence.


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BGP Enabled ServiceS (bess)

WG Name BGP Enabled ServiceS
Acronym bess
Area Routing Area (rtg)
State Active
Charter charter-ietf-bess-02 Approved
Status update Show Changed 2020-03-03
Document dependencies
Additional resources Implementation Requirement Policy
Issue tracker
WiKi
Wiki - Retired. No longer maintained
Zulip Stream
Personnel Chairs Matthew Bocci, Stephane Litkowski, Zhaohui (Jeffrey) Zhang
Area Director Gunter Van de Velde
Secretary Mankamana Prasad Mishra
Mailing list Address bess@ietf.org
To subscribe https://www.ietf.org/mailman/listinfo/bess
Archive https://mailarchive.ietf.org/arch/browse/bess/
Chat Room address https://zulip.ietf.org/#narrow/stream/bess

Charter for Working Group

BGP is established as a protocol for provisioning and operating Layer-3 (routed) Virtual Private Networks (L3VPNs) and Layer-2 Virtual Private Networks (L2VPNs).

The BGP Enabled Services (BESS) working group (WG) is responsible for defining, specifying, and extending VPN services over a packet switched network (PSN) where the VPN signaling uses BGP. The following services are in-scope:

  • BGP-enabled IP VPN solutions (based on RFC4364, RFC4659, RFC6513, RFC6514 and RFC9252) for supporting unicast and multicast provider-provisioned L3VPNs.
  • BGP-enabled L2VPNs (based on RFC4664, RFC7432 and RFC9252). Only types of L2VPN that utilize BGP for discovery, signaling, or for some other purposes related to the VPN are in scope. L2VPN solutions that do not utilize BGP for any of these purposes are out of scope of the BESS WG.
  • BGP-enabled VPN solutions for use in data center networking. This work includes consideration of VPN scaling issues and mechanisms applicable to such environments.
  • Extensions to BGP-enabled VPN solutions to enable interworking between BGP L3VPNs and BGP L2VPNs.

The WG may also suggest new services to be supported by BGP and these may be added to the WG charter subject to rechartering, and they will not be adopted in the WG until such rechartering.

The WG will primarily focus on the development of standards track specifications for BGP-based services in its charter. In addition, the WG may produce Informational documents, limited to operational and deployment considerations related to services for which the WG is also developing protocol specifications.

As part of enhancing and maintaining the services that the WG has specified, the following is a list of specific aspects that the WG is expected to work on:

a) BGP signaling related to the discovery of service endpoints and their capabilities that are related to the service.
b) The exchange of service routes and their provisioning.
c) Scaling and convergence improvements.
d) Interworking between different services.
e) Definition of YANG data models for device provisioning and operations.
f) Redundancy, multi-homing, load-balancing, and similar resiliency mechanisms.
g) OAM mechanisms related to services within the scope of the WG, following coordination with the WGs responsible for the underlying data plane technologies.
h) Informational documents that describe operational practices, deployment considerations, and implementation experiences related to services for which the WG is also developing standard track protocol specifications.
i) BGP signaling related to multicast services. This includes BGP components that are also applicable to the underlay PSN and that are detailed in specifications already adopted at the time of this charter revision (i.e. draft-ietf-bess-bgp-multicast-controller and draft-ietf-bess-bgp-multicast).
j) Specifications for BGP-enabled VPN solutions for SD-WAN environments that are already adopted at the time of this charter revision (i.e. draft-ietf-bess-bgp-sdwan-usage).

The WG will not define new data plane or forwarding encapsulations. Instead, it will rely on existing encapsulation mechanisms. These include, but are not limited to, IP-based encapsulations (such as IP-in-IP, VXLAN, GENEVE, and SRv6) and MPLS.

The WG is expected to coordinate closely with the IDR WG. Any extensions that impact core BGP protocol behavior, including modifications to the BGP finite state machine, message formats, best-path selection procedures, or the definition of new path attributes, must be cross-posted to the IDR WG for review. While technical discussions may occur on the BESS WG mailing list, work affecting the base BGP protocol remains subject to coordination with the IDR WG.

The WG will also liaise with other relevant WGs, including but not limited to MPLS, SPRING, 6MAN, NVO3, MBONED, and BFD, as appropriate. This coordination aims to ensure architectural consistency, alignment of data plane considerations, and interoperability of OAM procedures for BGP-based VPN solutions.

Milestones

Date Milestone Associated documents
Dec 2026 Submit a Yang device data model for E-VPN to IESG as PS draft-ietf-bess-evpn-yang
Dec 2026 Submit a YANG device data model for mVPN to IESG as PS draft-ietf-bess-mvpn-yang
Dec 2026 Submit a YANG device data model for L2VPN to IESG as PS draft-ietf-bess-l2vpn-yang
Dec 2026 Submit a Yang device data model for RFC4364 to IESG as PS draft-ietf-bess-l3vpn-yang
Dec 2026 Submit EVPN Fast Reroute to IESG as PS draft-ietf-bess-evpn-fast-reroute
Mar 2026 Submit EVPN multi-homing for L2 gateway protocols to IESG as PS draft-ietf-bess-evpn-l2gw-proto
Mar 2026 Submit E-VPN OAM to IESG as PS draft-ietf-bess-evpn-bfd
Mar 2026 Submit update to EVPN base spec (RFC7432bis) to IESG as PS draft-ietf-bess-rfc7432bis
Mar 2026 Submit specifications for BGP components that are applicable to both overlay BESS service and underlay PSN as PS draft-ietf-bess-bgp-multicast-controller
draft-ietf-bess-bgp-multicast
Dec 2025 Submit Weighted Multipath for EVPN to IESG as PS draft-ietf-bess-evpn-unequal-lb
Dec 2025 Submit VPLS multihoming to IESG as PS draft-ietf-bess-vpls-multihoming
Dec 2025 Submit BGP Usage for SD-WAN Overlay Networks to IESG as Informational draft-ietf-bess-bgp-sdwan-usage