Segment Routing (SR) leverages the source routing paradigm. A node steers a packet through an ordered list of instructions, called “segments”. A segment can represent any instruction, topological or service based. A segment can have a semantic local to an SR node or global within an SR domain. SR provides a mechanism that allows a flow to be restricted to a specific topological path, while maintaining per-flow state only at the ingress node(s) to the SR domain.
SR can be applied to the IPv6 architecture, with a new type of routing header, called Segment Routing Header(SRH). A segment is encoded as an IPv6 address. An ordered list of segments is encoded as an ordered list of IPv6 addresses in the routing header. The active segment is indicated by the Destination Address (DA) of the packet. The next active segment is indicated by a pointer in the new routing header.
1.2020 EANTC White Paper
Publication URL: PDF – 2020 EANTC White Paper
It includes the interoperability test cases to probe the maturity of transport network solutions to support 5G networks, data center networking evolution, and multi-vendor domain orchestration.
2. What is SRv6 network programming?
This article introduces the basic definition and deployment of SRv6.
3. SRv6 Network Programming
Publication URL: https://datatracker.ietf.org/doc/html/rfc8986
This document defines the SRv6 Network Programming concept and specifies the base set of SRv6 behaviors that enables the creation of interoperable overlays with underlay optimization (Service Level Agreements).
4. Segment Routing Header (SRH)
Publication URL: https://tools.ietf.org/html/rfc8754
This document describes the SRH and how it is used by nodes that are Segment Routing (SR) capable.
5. SRv6 NET-PGM extension: Insertion
This document extends SRv6 Network Programming with new SR endpoint and transit behaviors to be performed only within the SR domain in any packet owned by the domain.
6. Deployments With Insertion of IPv6 Segment Routing Headers
This document describes the usage of SRH insertion and deletion within the SR domain and how security and end-to-end integrity is guaranteed.
7. SRv6 Implementation and Deployment Status
This draft provides an overview of IPv6 Segment Routing (SRv6) deployment status. It lists various SRv6 features that have been deployed in the production networks. It also provides an overview of SRv6 implementation and interoperability testing status.
8. SRv6 Deployment Consideration
SRv6 has significant advantages over SR-MPLS and has attracted more and more attention and interest from network operators and verticals. Smooth network migration towards SRv6 is a key focal point and this document provides network migration guidance and recommendations on solutions in various scenarios. Deployment cases with SRv6 are also introduced.
9. SRv6 Compatibility with Legacy Devices
Publication URL: https://tools.ietf.org/html/draft-peng-spring-srv6-compatibility
When deploying SRv6 on legacy devices, there are some compatibility challenges that must be addressed such as the support for SRH processing.
This document identifies some of the major challenges, and provides solutions that can mitigate those challenges and smooth the migration towards SRv6 deployment.
10. Security Considerations for SRv6 Networks
SRv6 inherits potential security vulnerabilities from Source Routing in general, and also from IPv6. This document describes various threats and security concerns related to SRv6 networks and existing approaches to solve these threats.
11. SRv6 and MPLS interworking
Introduction: This document describes SRv6 and MPLS/SR-MPLS interworking and co-existence procedures.
1. ISIS Extensions for SRv6
Publication URL: https://tools.ietf.org/html/draft-ietf-lsr-isis-srv6-extensions
This draft describes the IS-IS extensions required to support Segment Routing over an IPv6 data plane.
2. OSPFv3 Extensions for SRv6
Publication URL: https://tools.ietf.org/html/draft-ietf-lsr-ospfv3-srv6-extensions
This draft describes the OSPFv3 extensions required to support Segment Routing over an IPv6 data plane (SRv6).
3. IGP Flexible Algorithm
Publication URL: https://tools.ietf.org/html/draft-ietf-lsr-flex-algo
This document proposes a solution that allows IGPs themselves to compute constraint based paths over the network. This document also specifies a way of using Segment Routing (SR) Prefix-SIDs and SRv6 locators to steer packets along the constraint-based paths.
1. BGP Link State Extensions for SRv6
Publication URL: https://tools.ietf.org/html/draft-ietf-idr-bgpls-srv6-ext
This draft defines extensions to the BGP-LS to advertise SRv6 Segments along with their behaviors and other attributes via BGP.
2. Segment Routing Policy Architecture
Publication URL: https://tools.ietf.org/html/draft-ietf-spring-segment-routing-policy
This document details the concepts of SR Policy and steering into an SR Policy.
3.Advertising Segment Routing Policies in BGP
Publication URL: https://tools.ietf.org/html/draft-ietf-idr-segment-routing-te-policy
This document specifies the way in which BGP may be used to distribute SR Policy candidate paths. New sub-TLVs for the Tunnel Encapsulation Attribute are defined for signaling information about these candidate paths.
4.BGP Request for Candidate Paths of SR TE Policies
Publication URL: https://tools.ietf.org/html/draft-li-ldr-bgp-request-cp-sr-te-policy
This document defines extensions to BGP for the headend to request BGP speaker (controller) for advertising the candidate paths.
5.PCEP extension to support Segment Routing Policy Candidate Paths
Publication URL: https://tools.ietf.org/html/draft-ietf-pce-segment-routing-policy-cp
This document proposes extension to PCEP to support association among candidate paths of a given SR policy. The mechanism proposed in this document is applicable to both MPLS and IPv6 data planes of SR.
6.PCEP Extensions for Segment Routing leveraging the IPv6 data plane
Publication URL: https://tools.ietf.org/html/draft-ietf-pce-segment-routing-ipv6
This document describes the extensions required for SR support for IPv6 data plane in Path Computation Element communication Protocol (PCEP). The PCEP extension and mechanism to support SR-MPLS is described in RFC 8664. This document extends it to support SRv6 (SR over IPv6).
7.BGP Color-Aware Routing Problem Statement
This document explores the scope, use-cases and requirements for a BGP based routing solution to establish end-to-end intent-aware paths across a multi-domain service provider network environment.
8. BGP Color-Aware Routing (CAR)
Publication URL: https://datatracker.ietf.org/doc/html/draft-dskc-bess-bgp-car
This document describes a BGP based routing solution to establish end-to-end intent-aware paths across a multi-domain service provider transport network. This solution is called BGP Color-Aware Routing (BGP CAR).
9. Seamless SR Problem Statement
This draft documents a set of use cases and requirements for end-to-end intent-based paths spanning multi-domain packet networks. The document explicitly focuses on use cases that require high scale and availability, which will likely benefit from distributed solutions. It is intended that the requirements in this document serve as a basis for future IETF work to develop distributed solutions for inter-domain intent-based transport paths.
10. BGP Classful Transport Planes
This document specifies a mechanism, referred to as “service mapping”, to express association of overlay routes with underlay routes satisfying a certain SLA, using BGP. The document describes a framework for classifying underlay routes into transport classes, and mapping service routes to specific transport class.
1. SRv6 VPN
Publication URL: https://tools.ietf.org/html/draft-ietf-bess-srv6-services/
This draft defines procedures and messages for SRv6-based BGP services including L3VPN, EVPN and Internet services. It builds on RFC4364 “BGP/MPLS IP Virtual Private Networks (VPNs)” and RFC7432 “BGP MPLS-Based Ethernet VPN”.
SRv6 E2E protection
1. SRv6 Path Egress Protection
Publication URL: https://tools.ietf.org/html/draft-ietf-rtgwg-srv6-egress-protection
This document describes protocol extensions for protecting the egress node of a Segment Routing for IPv6 (SRv6) path or tunnel.
2. SR-TE Path Midpoint Protection
This document describes a mechanism that allows traffic to continue to be forwarded on an SR-TE path for an extended period of time after the failure of a node used in the path’s segment list.
3. SRv6 Midpoint Protection
This document defines midpoint protection, which enables the direct neighbor of the failed endpoint to do the function of the endpoint, replace the IPv6 destination address to the other endpoint, and choose the next hop based on the new destination address.
1. YANG Data Model for SRv6 Base and Static
Publication URL: https://tools.ietf.org/html/draft-ietf-spring-srv6-yang
This document describes a YANG data model for Segment Routing IPv6(SRv6) base. The model serves as a base framework for configuring and managing an SRv6 subsystem and expected to be augmented by other SRv6 technology models accordingly. Additionally, this document also specifies the model for the SRv6 Static application.
2. YANG Data Model for IS-IS SRv6
Publication URL: https://tools.ietf.org/html/draft-hu-isis-srv6-yang
This document defines a YANG data model that can be used to configure and manage IS-IS SRv6.
3. YANG Data Model for OSPF SRv6
Publication URL: https://tools.ietf.org/html/draft-hu-lsr-ospf-srv6-yang
This document defines a YANG data model that can be used to configure and manage OSPFv3 SRv6.
4. YANG Data Model for Segment Routing Policy
Publication URL: https://datatracker.ietf.org/doc/draft-ietf-spring-sr-policy-yang
This document defines a YANG data model for Segment Routing (SR) Policy that can be used for configuring, instantiating, and managing SR policies. The model is generic and apply equally to the MPLS and SRv6 instantiations of SR policies. The document has just been WG adopted.
5. Yang Data Model for SRv6 based Services
Publication URL: https://tools.ietf.org/html/draft-raza-bess-srv6-services-yang
This document defines a YANG data model that can be used to configure and manage SRv6 based services in BGP.
6. A YANG Data Model for Segment Routing in IPv6 (SRv6) support in Path Computation Element Communications Protocol (PCEP)
Publication URL: https://tools.ietf.org/html/draft-li-pce-pcep-srv6-yang
This document augments a YANG data model for the management of Path Computation Element communications Protocol (PCEP) for communications between a Path Computation Client (PCC) and a Path Computation Element (PCE), or between two PCEs in support for Segment Routing in IPv6. The data model includes configuration data and state data (status information and counters for the collection of statistics).