SPRING Working Group T. Saleh, Ed. Internet-Draft K. Raza Intended status: Standards Track Cisco Systems Expires: 7 January 2027 Z. Shunwan Huawei Technologies S. Matsushima SoftBank V. Beeram Juniper Networks 6 July 2026 YANG Data Model for Segment Routing Policy draft-ietf-spring-sr-policy-yang-08 Abstract 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 applies equally to the MPLS and SRv6 instantiations of SR policies. Status of This Memo 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 7 January 2027. Copyright Notice 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 Saleh, et al. Expires 7 January 2027 [Page 1] Internet-Draft YANG Data Model for SR Policy July 2026 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. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Specification of Requirements . . . . . . . . . . . . . . . . 3 3. Building Blocks . . . . . . . . . . . . . . . . . . . . . . . 3 4. YANG Model . . . . . . . . . . . . . . . . . . . . . . . . . 4 4.1. Prefixes in Data Node Names . . . . . . . . . . . . . . . 5 4.2. Types and Definitions . . . . . . . . . . . . . . . . . . 5 4.3. SR Policy . . . . . . . . . . . . . . . . . . . . . . . . 6 4.3.1. Configuration . . . . . . . . . . . . . . . . . . . . 7 4.3.2. State . . . . . . . . . . . . . . . . . . . . . . . . 9 4.3.3. Notification . . . . . . . . . . . . . . . . . . . . 10 5. Pending Items . . . . . . . . . . . . . . . . . . . . . . . . 10 6. YANG Tree . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7. YANG Specification . . . . . . . . . . . . . . . . . . . . . 24 7.1. Types . . . . . . . . . . . . . . . . . . . . . . . . . . 24 7.2. SR Policy . . . . . . . . . . . . . . . . . . . . . . . . 34 8. Security Considerations . . . . . . . . . . . . . . . . . . . 69 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 70 10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 71 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 71 11.1. Normative References . . . . . . . . . . . . . . . . . . 71 11.2. Informative References . . . . . . . . . . . . . . . . . 73 Appendix A. Contributors . . . . . . . . . . . . . . . . . . . . 74 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 74 1. Introduction The Network Configuration Protocol (NETCONF) [RFC6241] defines mechanisms to manage network devices. YANG [RFC7950] is a modular language that represents data structures in an XML tree format, and is used as a data modeling language for NETCONF. Segment Routing (SR), as defined in [RFC8402], allows a headend node to steer a packet flow along any topological path and/or service chain. The headend node is said to steer a flow into a Segment Routing Policy (SR Policy). An SR policy is a framework that enables instantiation of an ordered list of segments on a node for implementing a policy [RFC9256]. Saleh, et al. Expires 7 January 2027 [Page 2] Internet-Draft YANG Data Model for SR Policy July 2026 This document introduces a YANG data model for SR policy framework for instantiating, configuring and managing SR policies along with its attributes. It is also expected that other companion models, such as BGP SR Policy [I-D.ietf-idr-segment-routing-te-policy], will be defined and/or augmented accordingly in their respective areas. This model defines the following constructs for managing an SR policy: * Configuration * Operational State * Notifications This document expects and requires the reader to be well familiar with the concepts and constructs of an SR policy [RFC9256] as well as the YANG modeling language and its presentation [RFC7950]. This document uses the YANG terminology defined in Section 3 of [RFC7950]. The meanings of the symbols in the YANG module tree diagrams are defined in [RFC8340]. 2. Specification of Requirements The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD 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. 3. Building Blocks Before looking into the YANG model for SR policy, it is important to recall and highlight the major building blocks and constructs that constitute and contribute to an SR policy, as described in [RFC9256]. * policy: specifies constructs to allow a headend node to setup SR path(s) as an ordered list of segments for a given color and endpoint. The endpoint and the color are used to automate the steering of service or transport routes on an SR Policy. In this model, an SR policy is keyed globally by (headend, color, endpoint), where endpoint is an IP address that could also be NULL. Saleh, et al. Expires 7 January 2027 [Page 3] Internet-Draft YANG Data Model for SR Policy July 2026 * candidate-path: is the unit for signalling of an SR Policy to a headend via protocols (such as PCEP, BGP, CLI etc.). A candidate path is either dynamic or explicit type, where an explicit candidate path is associated with one or more segment-lists and dynamic candidate path expresses optimization objectives and a set of path constraints. An SR Policy is associated with one or more candidate paths and the preference of the candidate path is used to select the best candidate path for an SR Policy. A candidate path is valid if it is usable (e.g. when its constituents SIDs are reachable). An "active" candidate path is the selected path (for forwarding) that is valid and determined to be the best path of the SR Policy. A candidate path is keyed by (protocol-origin, originator-asn, originator-node-address, discriminator). * segment-list: specifies ordered list of segments to traverse, where a segment can be specified in various forms (refer section 4 of [RFC9256]). The list is sorted by the index of the segment. A segment-list is used and referred by an explicit type of candidate-path. A segment-list is keyed by its name. * binding-sid: An SR policy is associated with a BSID to provide benefits of scaling, network opacity and service independence. 4. YANG Model The modeling in this document complies with the Network Management Datastore Architecture (NMDA) [RFC8342]. The operational state data is combined with the associated configuration data in the same hierarchy [RFC8407]. When protocol states are retrieved from the NMDA operational state datastore, the returned states cover all "config true" (rw) and "config false" (ro) nodes defined in the schema. For SR policy YANG specification, this document defines following new YANG modules: Saleh, et al. Expires 7 January 2027 [Page 4] Internet-Draft YANG Data Model for SR Policy July 2026 +======================+========================================+ | Module Name | Purpose | +======================+========================================+ | ietf-sr-policy-types | defines common and basic types related | | | to an SR policy and related constructs | +----------------------+----------------------------------------+ +----------------------+----------------------------------------+ | ietf-sr-policy | defines the model for SR policy | | | instantiation, configuration, and | | | management | +----------------------+----------------------------------------+ Table 1 4.1. Prefixes in Data Node Names The tree diagrams and data node names in this document use prefixes from the following external modules. +============+====================+================================+ | Prefix | YANG Module | Reference | +============+====================+================================+ | inet | ietf-inet-types | [RFC6991] | +------------+--------------------+--------------------------------+ | if | ietf-interfaces | [RFC8343] | +------------+--------------------+--------------------------------+ | rt | ietf-routing | [RFC8349] | +------------+--------------------+--------------------------------+ | rt-types | ietf-routing-types | [RFC8294] | +------------+--------------------+--------------------------------+ | srv6-types | ietf-srv6-types | [I-D.ietf-spring-srv6-yang] | +------------+--------------------+--------------------------------+ | te-types | ietf-te-types | [I-D.ietf-teas-rfc8776-update] | +------------+--------------------+--------------------------------+ | yang | ietf-yang-types | [RFC6991] | +------------+--------------------+--------------------------------+ Table 2: Prefixes and Corresponding YANG Modules 4.2. Types and Definitions SR policy common types and definitions are defined in the new module "ietf-sr-policy-types". The main types defined in this module include: * dataplane-type: A union to specify MPLS or IPv6 as the dataplane type for SR. Saleh, et al. Expires 7 January 2027 [Page 5] Internet-Draft YANG Data Model for SR Policy July 2026 * sid-value-type: A Union to specify SID value for SR-MPLS or SRv6 type. * binding-sid-alloc-mode: Enum to define explicit or dynamic alloc mode types for a BSID. * protocol-origin-type: The base identity along with its children specify protocol origin (e.g. PCEP) for an SR policy. * explicit-binding-sid-rule-type: Enum to specify BSID alloc enforcement/rule when doing explicit alloc request. * binding-sid-oper-state: An Enum representing various operational states for a BSID. * policy-admin-state: An Enum for admin state of an SR policy. * policy-oper-state: An Enum for operational state of an SR policy. * segment-type: The base identity along with its children define various types for a "segment" of a Segment list. * candidate-path-not-selected-reason: The base identity along with its children to specify reason for not selecting a candidate path as the best/active path. * policy-down-reason: The base identity along with its children to specify reason for a policy becoming (or remaining) operationally down. * binding-sid-unavailable-reason: The base identity along with its children to specify reason for a BSID's unavailability. The associated YANG specification for this module is captured in Section 7.1. 4.3. SR Policy The base SR policy model is captured in ietf-sr-policy module. This base module augments "/rt:routing" and specifies the configuration, operational state, and notification events required to manage SR policies. The associated YANG specification for this module is captured in Section 7.2. Saleh, et al. Expires 7 January 2027 [Page 6] Internet-Draft YANG Data Model for SR Policy July 2026 4.3.1. Configuration In terms of configuration hierarchy, SR policy configuration tree has following three main areas: * optimization-templates: container that defines list of templates per color. The template is used to define a set of optimization objectives and constraints used to instantiate an SR policy on- demand. * attributes: container that defines common constructs that could be used across policies. Examples of such constructs include segment-lists and explicit binding-SID rules. In future revisions of this document, it is expected that this container will have more constructs defined. * policies: container that defines list of policies with their attributes such as BSID, candidate-paths etc. Following diagram depicts high level yang organization and hierarchy for an SR policy specification: Saleh, et al. Expires 7 January 2027 [Page 7] Internet-Draft YANG Data Model for SR Policy July 2026 segment-routing traffic-engineering +--rw optimization-templates | +--rw optimization-template* [color] | +--rw color uint32 | +--rw candidate-paths | +--rw candidate-path* [discriminator] | | .... | + attributes | + segment-lists | | segment-list* [name] | | segments | | segment* [index] | | ... | + explicit-binding-sid-rules | ... | + policies policy* [headend color endpoint] + ... | + binding-sid | ... | + candidate-paths candidate-path* [protocol-origin originator-asn originator-node-address discriminator] + ... | + type + explicit | segment-lists | segment-list* [ref] | ... + dynamic + optimization-objectives | ... + constraints ... Figure 1: SR Policy - Hierarchy The complete YANG tree can be found in Figure 2. Please take note of the following important points regarding the configurations: Saleh, et al. Expires 7 January 2027 [Page 8] Internet-Draft YANG Data Model for SR Policy July 2026 * This model supports both MPLS and SRv6 dataplane for SR -- i.e. items like segments and BSID can be defined as MPLS label or SRv6 SIDs. * Specification of a segment supports all the types defined in SR policy base specification document * The above model supports explicit BSID specification on SR policy level as the main mode of specification. The model also allows explicit BSID per candidate-path as an if-feature capability that is optional for implementations * The above model includes dynamic candidate-path constraints and optimization objectives, including TE-based path metric bounds, SRLG and affinity constraints, disjointness, SR-local MSD constraint encoding through path-metric bounds, and bandwidth typing. The reused TE optimization metric grouping still appears in the schema tree with inherited explicit-route-include-objects and explicit-route-exclude-objects subtrees, but those subtrees are not applicable in SR Policy because minimize-metric disallows the TE route-object optimization identities that activate them. Future revisions of this document may add traffic-steering controls. 4.3.2. State As per NMDA model, the state related to configuration items specified in earlier Section 4.3.1 can be retrieved from the same tree. This section defines the other operational state items related to SR policy. In addition to configured state, the operational state corresponding to the SR policy includes: * policy operational state * policy up/down timestamps * policy BSID info such as alloc mode, actual value in-use, operational state, and forwarding stats * Per candidate-path info such as: - Whether candidate-path is the best candidate-path - In case of non-best, the reason for such non-selection - Type of candidate-path - explicit or dynamic Saleh, et al. Expires 7 January 2027 [Page 9] Internet-Draft YANG Data Model for SR Policy July 2026 - Per segment-list information - such as validity of the segment- list, as well as forwarding state for a valid segment-list. The forwarding state is represented in terms of per forwarding path info that includes nexthop address, outgoing interface, protection information, and encapsulation (label stack or SRv6 SID stack) etc. The complete YANG tree can be found in Figure 2. 4.3.3. Notification This model defines a list of notifications to inform an operator of important events detected regarding an SR policy. These events include events related to: * policy status: policy operational state changes * Candidate-path active status and changes * Explicit Binding SID collision/unavailability events Section 6 captures the YANG tree for the notification. 5. Pending Items Following are the items that will be addressed in future revisions of this document: * Configuration and Specification of: - Traffic steering over SR policy - Spray policy * Executables (RPC actions) 6. YANG Tree Using the building blocks described in Section 3, following is the complete graphical representation of the data model for SR policy: The tree below still shows the inherited explicit-route-include- objects and explicit-route-exclude-objects subtrees under minimize- metric because they are part of the reused TE optimization grouping. Those subtrees are not applicable in SR Policy because minimize- metric disallows the TE route-object optimization identities that activate them. Saleh, et al. Expires 7 January 2027 [Page 10] Internet-Draft YANG Data Model for SR Policy July 2026 module: ietf-sr-policy augment /rt:routing: +--rw segment-routing +--rw traffic-engineering +--rw optimization-templates | +--rw optimization-template* [color] | +--rw color uint32 | +--rw candidate-paths | +--rw candidate-path* [discriminator] | +--rw discriminator uint32 | +--rw optimization-objectives | | +--rw minimize-metric* [metric-type] | | +--rw metric-type | | | identityref | | +--rw weight? | | | uint8 | | +--rw explicit-route-exclude-objects | | | +--rw route-object-exclude-object* | | | [index] | | | +--rw index | | | | uint32 | | | +--rw (type)? | | | +--:(numbered-node-hop) | | | | +--rw numbered-node-hop | | | | +--rw node-id-uri? | | | | | nw:node-id | | | | +--rw node-id? | | | | | te-node-id | | | | +--rw hop-type? | | | | te-hop-type | | | +--:(numbered-link-hop) | | | | +--rw numbered-link-hop | | | | +--rw link-tp-id | | | | | te-tp-id | | | | +--rw hop-type? | | | | | te-hop-type | | | | +--rw direction? | | | | te-link-direction | | | +--:(unnumbered-link-hop) | | | | +--rw unnumbered-link-hop | | | | +--rw link-tp-id-uri? | | | | | nt:tp-id | | | | +--rw link-tp-id? | | | | | te-tp-id | | | | +--rw node-id-uri? | | | | | nw:node-id | | | | +--rw node-id? Saleh, et al. Expires 7 January 2027 [Page 11] Internet-Draft YANG Data Model for SR Policy July 2026 | | | | | te-node-id | | | | +--rw hop-type? | | | | | te-hop-type | | | | +--rw direction? | | | | te-link-direction | | | +--:(as-number) | | | | +--rw as-number-hop | | | | +--rw as-number | | | | | inet:as-number | | | | +--rw hop-type? | | | | te-hop-type | | | +--:(label) | | | | +--rw label-hop | | | | +--rw te-label | | | | +--rw (technology)? | | | | | +--:(generic) | | | | | +--rw generic? | | | | | rt-types: | | | | | generalized-label | | | | +--rw direction? | | | | te-label-direction | | | +--:(srlg) | | | +--rw srlg | | | +--rw srlg? uint32 | | +--rw explicit-route-include-objects | | | +--rw route-object-include-object* | | | [index] | | | +--rw index | | | | uint32 | | | +--rw (type)? | | | +--:(numbered-node-hop) | | | | +--rw numbered-node-hop | | | | +--rw node-id-uri? | | | | | nw:node-id | | | | +--rw node-id? | | | | | te-node-id | | | | +--rw hop-type? | | | | te-hop-type | | | +--:(numbered-link-hop) | | | | +--rw numbered-link-hop | | | | +--rw link-tp-id | | | | | te-tp-id | | | | +--rw hop-type? | | | | | te-hop-type | | | | +--rw direction? | | | | te-link-direction | | | +--:(unnumbered-link-hop) | | | | +--rw unnumbered-link-hop Saleh, et al. Expires 7 January 2027 [Page 12] Internet-Draft YANG Data Model for SR Policy July 2026 | | | | +--rw link-tp-id-uri? | | | | | nt:tp-id | | | | +--rw link-tp-id? | | | | | te-tp-id | | | | +--rw node-id-uri? | | | | | nw:node-id | | | | +--rw node-id? | | | | | te-node-id | | | | +--rw hop-type? | | | | | te-hop-type | | | | +--rw direction? | | | | te-link-direction | | | +--:(as-number) | | | | +--rw as-number-hop | | | | +--rw as-number | | | | | inet:as-number | | | | +--rw hop-type? | | | | te-hop-type | | | +--:(label) | | | +--rw label-hop | | | +--rw te-label | | | +--rw (technology)? | | | | +--:(generic) | | | | +--rw generic? | | | | rt-types: | | | | generalized-label | | | +--rw direction? | | | te-label-direction | | +--rw margin | | +--rw type? | | | sr-policy-types:margin-type | | +--rw value? uint32 | | +--ro computed-value? uint32 | +--rw constraints | +--rw path-constraints | | +--rw path-metric-bounds | | | +--rw path-metric-bound* [metric-type] | | | +--rw metric-type identityref | | | +--rw upper-bound? uint64 | | +--rw path-affinities-values | | | +--rw path-affinities-value* [usage] | | | +--rw usage identityref | | | +--rw value? admin-groups | | +--rw path-affinity-names | | | +--rw path-affinity-name* [usage] | | | +--rw usage identityref | | | +--rw affinity-name* [name] | | | +--rw name string Saleh, et al. Expires 7 January 2027 [Page 13] Internet-Draft YANG Data Model for SR Policy July 2026 | | +--rw path-srlgs-lists | | | +--rw path-srlgs-list* [usage] | | | +--rw usage identityref | | | +--rw values* srlg | | +--rw path-srlgs-names | | +--rw path-srlgs-name* [usage] | | +--rw usage identityref | | +--rw names* string | +--rw ip-address | | +--rw exclude* inet:ip-address | +--rw segment-rules | +--rw sid-protection-eligibility? | sr-policy-types: | sid-protection-eligibility-type +--rw attributes | +--rw segment-lists | | +--rw segment-list* [name] | | +--rw name string | | +--rw segments | | +--rw segment* [index] | | +--rw index uint32 | | +--rw type identityref | | +--rw sr-mpls | | | +--rw Type-A | | | | +--rw value? rt-types:mpls-label | | | +--rw Type-C | | | | +--rw ipv4-address? | | | | | inet:ipv4-address | | | | +--rw algorithm? uint8 | | | +--rw Type-D | | | | +--rw ipv6-address? | | | | | inet:ipv6-address | | | | +--rw algorithm? uint8 | | | +--rw Type-E | | | | +--rw ipv4-address? | | | | | inet:ipv4-address | | | | +--rw interface-identifier? uint32 | | | +--rw Type-F | | | | +--rw local-ipv4-address? | | | | | inet:ipv4-address | | | | +--rw remote-ipv4-address? | | | | inet:ipv4-address | | | +--rw Type-G | | | | +--rw local-ipv6-address? | | | | | inet:ipv6-address | | | | +--rw local-interface-identifier? | | | | | uint32 | | | | +--rw remote-ipv6-address? Saleh, et al. Expires 7 January 2027 [Page 14] Internet-Draft YANG Data Model for SR Policy July 2026 | | | | | inet:ipv6-address | | | | +--rw remote-interface-identifier? | | | | uint32 | | | +--rw Type-H | | | +--rw local-ipv6-address? | | | | inet:ipv6-address | | | +--rw remote-ipv6-address? | | | inet:ipv6-address | | +--rw srv6 | | | +--rw Type-B | | | | +--rw value? | | | | | srv6-types:srv6-sid | | | | +--rw sid-behavior? identityref | | | | +--rw sid-structure | | | | +--rw locator-block-length? | | | | | srv6-types: | | | | | srv6-locator-block-len | | | | +--rw locator-node-length? | | | | | srv6-types: | | | | | srv6-locator-node-len | | | | +--rw function-length? | | | | | srv6-types: | | | | | srv6-sid-func-len | | | | +--rw argument-length? | | | | srv6-types:srv6-sid-arg-len | | | +--rw Type-I | | | | +--rw ipv6-address? | | | | | inet:ipv6-address | | | | +--rw algorithm? uint8 | | | +--rw Type-J | | | | +--rw local-ipv6-address? | | | | | inet:ipv6-address | | | | +--rw local-interface-identifier? | | | | | uint32 | | | | +--rw remote-ipv6-address? | | | | | inet:ipv6-address | | | | +--rw remote-interface-identifier? | | | | uint32 | | | +--rw Type-K | | | +--rw local-ipv6-address? | | | | inet:ipv6-address | | | +--rw remote-ipv6-address? | | | inet:ipv6-address | | +--rw validate? boolean | +--rw explicit-binding-sid-rules* [index] | +--rw index uint32 | +--rw rule | sr-policy-types: Saleh, et al. Expires 7 January 2027 [Page 15] Internet-Draft YANG Data Model for SR Policy July 2026 | explicit-binding-sid-rule-type +--rw policies +--rw policy* [headend color endpoint] +--rw name? sr-policy-types:name-type +--rw headend inet:ip-address +--rw color sr-policy-types:color-type +--rw endpoint inet:ip-address +--rw description? string +--rw admin-state? | sr-policy-types:policy-admin-state +--rw priority? uint8 +--rw profile-id? uint32 +--rw bandwidth | +--rw requested? te-types:te-bandwidth | +--ro reserved? te-types:te-bandwidth +--ro oper-state? | sr-policy-types:policy-oper-state +--ro transition-count? uint32 +--ro up-time? yang:date-and-time +--ro down-time? yang:date-and-time +--rw binding-sid | +--rw mpls-sid | | +--rw value? | | | sr-policy-types:mpls-sid-value-type | | +--ro alloc-mode? | | | sr-policy-types:binding-sid-alloc-mode | | +--ro allocated-sid? | | | sr-policy-types:sid-value-type | | +--ro oper-state? | | sr-policy-types:binding-sid-oper-state | +--rw srv6-sids | +--rw srv6-sid* [index] | +--rw index uint32 | +--rw locator-name? | | srv6-types:srv6-locator-name-type | +--rw value? srv6-types:srv6-sid | +--rw sid-behavior? identityref | +--rw sid-structure | | +--rw locator-block-length? | | | srv6-types:srv6-locator-block-len | | +--rw locator-node-length? | | | srv6-types:srv6-locator-node-len | | +--rw function-length? | | | srv6-types:srv6-sid-func-len | | +--rw argument-length? | | srv6-types:srv6-sid-arg-len | +--ro alloc-mode? | | sr-policy-types: Saleh, et al. Expires 7 January 2027 [Page 16] Internet-Draft YANG Data Model for SR Policy July 2026 | | binding-sid-alloc-mode | +--ro allocated-sid? | | sr-policy-types:sid-value-type | +--ro oper-state? | sr-policy-types: | binding-sid-oper-state +--ro counters | +--ro pkts? yang:counter64 | +--ro octets? yang:counter64 +--rw candidate-paths +--rw candidate-path* [ protocol-origin originator-asn originator-node-address discriminator] +--rw protocol-origin | identityref +--rw originator-asn uint32 +--rw originator-node-address | sr-policy-types:node-address-type +--rw discriminator uint32 +--rw preference uint32 +--rw name? string +--rw description? string +--rw drop-upon-invalid? boolean +--rw admin-state? boolean +--rw binding-sid | {capability-candidate-path-binding-sid}? | +--rw mpls-sid | | +--rw value? | | sr-policy-types: | | mpls-sid-value-type | +--rw srv6-sids | +--rw srv6-sid* [index] | +--rw index uint32 | +--rw locator-name? | | srv6-types: | | srv6-locator-name-type | +--rw value? | | srv6-types:srv6-sid | +--rw sid-behavior? identityref | +--rw sid-structure | +--rw locator-block-length? | | srv6-types: | | srv6-locator-block-len | +--rw locator-node-length? | | srv6-types: Saleh, et al. Expires 7 January 2027 [Page 17] Internet-Draft YANG Data Model for SR Policy July 2026 | | srv6-locator-node-len | +--rw function-length? | | srv6-types: | | srv6-sid-func-len | +--rw argument-length? | srv6-types:srv6-sid-arg-len +--rw (type)? | +--:(explicit) | | +--rw segment-lists | | +--rw segment-list* [name-ref] | | +--rw name-ref leafref | | +--rw weight? uint32 | | +--ro is-valid? boolean | | +--ro counters | | +--ro pkts? yang:counter64 | | +--ro octets? yang:counter64 | +--:(dynamic) | | +--rw segment-list | | | +--rw segment-list-dataplane-type | | | | sr-policy-types:dataplane-type | | | +--ro is-valid? | | | | boolean | | | +--ro counters | | | +--ro pkts? yang:counter64 | | | +--ro octets? yang:counter64 | | +--rw optimization-objectives | | | +--rw minimize-metric* [metric-type] | | | +--rw metric-type | | | | identityref | | | +--rw weight? | | | | uint8 | | | +--rw explicit-route-exclude-objects | | | | +--rw route-object-exclude-object* | | | | [index] | | | | +--rw index | | | | | uint32 | | | | +--rw (type)? | | | | +--:(numbered-node-hop) | | | | | +--rw numbered-node-hop | | | | | +--rw node-id-uri? | | | | | | nw:node-id | | | | | +--rw node-id? | | | | | | te-node-id | | | | | +--rw hop-type? | | | | | te-hop-type | | | | +--:(numbered-link-hop) | | | | | +--rw numbered-link-hop | | | | | +--rw link-tp-id Saleh, et al. Expires 7 January 2027 [Page 18] Internet-Draft YANG Data Model for SR Policy July 2026 | | | | | | te-tp-id | | | | | +--rw hop-type? | | | | | | te-hop-type | | | | | +--rw direction? | | | | | te-link-direction | | | | +--:(unnumbered-link-hop) | | | | | +--rw unnumbered-link-hop | | | | | +--rw link-tp-id-uri? | | | | | | nt:tp-id | | | | | +--rw link-tp-id? | | | | | | te-tp-id | | | | | +--rw node-id-uri? | | | | | | nw:node-id | | | | | +--rw node-id? | | | | | | te-node-id | | | | | +--rw hop-type? | | | | | | te-hop-type | | | | | +--rw direction? | | | | | te-link-direction | | | | +--:(as-number) | | | | | +--rw as-number-hop | | | | | +--rw as-number | | | | | | inet: | | | | | | as-number | | | | | +--rw hop-type? | | | | | te-hop-type | | | | +--:(label) | | | | | +--rw label-hop | | | | | +--rw te-label | | | | | +--rw (technology)? | | | | | | +--:(generic) | | | | | | +--rw generic? | | | | | | rt-types:generalized-label | | | | | +--rw direction? | | | | | te-label-direction | | | | +--:(srlg) | | | | +--rw srlg | | | | +--rw srlg? uint32 | | | +--rw explicit-route-include-objects | | | | +--rw route-object-include-object* | | | | [index] | | | | +--rw index | | | | | uint32 | | | | +--rw (type)? | | | | +--:(numbered-node-hop) | | | | | +--rw numbered-node-hop | | | | | +--rw node-id-uri? | | | | | | nw:node-id Saleh, et al. Expires 7 January 2027 [Page 19] Internet-Draft YANG Data Model for SR Policy July 2026 | | | | | +--rw node-id? | | | | | | te-node-id | | | | | +--rw hop-type? | | | | | te-hop-type | | | | +--:(numbered-link-hop) | | | | | +--rw numbered-link-hop | | | | | +--rw link-tp-id | | | | | | te-tp-id | | | | | +--rw hop-type? | | | | | | te-hop-type | | | | | +--rw direction? | | | | | te-link-direction | | | | +--:(unnumbered-link-hop) | | | | | +--rw unnumbered-link-hop | | | | | +--rw link-tp-id-uri? | | | | | | nt:tp-id | | | | | +--rw link-tp-id? | | | | | | te-tp-id | | | | | +--rw node-id-uri? | | | | | | nw:node-id | | | | | +--rw node-id? | | | | | | te-node-id | | | | | +--rw hop-type? | | | | | | te-hop-type | | | | | +--rw direction? | | | | | te-link-direction | | | | +--:(as-number) | | | | | +--rw as-number-hop | | | | | +--rw as-number | | | | | | inet: | | | | | | as-number | | | | | +--rw hop-type? | | | | | te-hop-type | | | | +--:(label) | | | | +--rw label-hop | | | | +--rw te-label | | | | +--rw (technology)? | | | | | +--:(generic) | | | | | +--rw generic? | | | | | rt-types:generalized-label | | | | +--rw direction? | | | | te-label-direction | | | +--rw margin | | | +--rw type? | | | | sr-policy-types: | | | | margin-type | | | +--rw value? uint32 | | | +--ro computed-value? uint32 Saleh, et al. Expires 7 January 2027 [Page 20] Internet-Draft YANG Data Model for SR Policy July 2026 | | +--rw constraints | | +--rw path-constraints | | | +--rw path-metric-bounds | | | | +--rw path-metric-bound* | | | | [metric-type] | | | | +--rw metric-type | | | | | identityref | | | | +--rw upper-bound? uint64 | | | +--rw path-affinities-values | | | | +--rw path-affinities-value* | | | | [usage] | | | | +--rw usage identityref | | | | +--rw value? admin-groups | | | +--rw path-affinity-names | | | | +--rw path-affinity-name* | | | | [usage] | | | | +--rw usage | | | | | identityref | | | | +--rw affinity-name* [name] | | | | +--rw name string | | | +--rw path-srlgs-lists | | | | +--rw path-srlgs-list* [usage] | | | | +--rw usage identityref | | | | +--rw values* srlg | | | +--rw path-srlgs-names | | | | +--rw path-srlgs-name* [usage] | | | | +--rw usage identityref | | | | +--rw names* string | | | +--rw disjointness? | | | te-path-disjointness | | +--rw ip-address | | | +--rw exclude* | | | | inet:ip-address | | | +--rw include-any* | | | | inet:ip-address | | | +--rw include-all* | | | inet:ip-address | | +--rw segment-rules | | | +--rw sid-algorithm? | | | | sr-policy-types: | | | | sid-algorithm-type | | | +--rw sid-protection-eligibility? | | | sr-policy-types: | | | sid-protection- | | | eligibility-type | | +--rw disjoint-path | | +--rw association-group-id | | | uint16 Saleh, et al. Expires 7 January 2027 [Page 21] Internet-Draft YANG Data Model for SR Policy July 2026 | | +--rw association-source | | | inet:ip-address | | +--rw association-extended-id? | | yang:hex-string | +--:(composite) | +--rw constituent-policies | +--rw constituent-policy* [color] | +--rw color | | sr-policy-types:color-type | +--rw weight? uint32 +--ro is-best-candidate-path? boolean +--ro non-selection-reason? | identityref +--ro is-active? boolean +--ro is-valid? boolean +--ro computed-sid-list | +--ro (dataplane-type)? | +--:(mpls) | | +--ro labels* [index] | | +--ro index uint32 | | +--ro label? rt-types:mpls-label | +--:(srv6) | +--ro sids* [index] | +--ro index uint32 | +--ro sid? srv6-types:srv6-sid +--ro forwarding-paths +--ro forwarding-path* [path-id] +--ro path-id uint8 +--ro next-hop-address? | inet:ip-address +--ro next-hop-table-id? uint32 +--ro interface? | if:interface-ref +--ro is-protected? boolean +--ro backup-path-id? uint8 +--ro is-pure-backup? boolean +--ro weight? uint32 +--ro sid-list | +--ro (dataplane-type)? | +--:(mpls) | | +--ro labels* [index] | | +--ro index uint32 | | +--ro label? | | rt-types:mpls-label | +--:(srv6) | +--ro sids* [index] | +--ro index uint32 | +--ro sid? Saleh, et al. Expires 7 January 2027 [Page 22] Internet-Draft YANG Data Model for SR Policy July 2026 | srv6-types:srv6-sid +--ro counters +--ro pkts? yang:counter64 +--ro octets? yang:counter64 notifications: +---n sr-policy-oper-state-change-event | +--ro policy-name-ref? leafref | +--ro policy-color-ref? leafref | +--ro policy-endpoint-ref? leafref | +--ro policy-new-oper-state? | | sr-policy-types:policy-oper-state | +--ro policy-down-reason? identityref +---n sr-policy-candidate-path-change-event | +--ro policy-name-ref? leafref | +--ro policy-color-ref? leafref | +--ro policy-endpoint-ref? leafref | +--ro existing-preference? uint32 | +--ro new-preference? uint32 +---n sr-policy-binding-sid-unavailable-event | +--ro policy-name-ref? leafref | +--ro policy-color-ref? leafref | +--ro policy-endpoint-ref? leafref | +--ro (dataplane-type)? | | +--:(mpls) | | | +--ro policy-mpls-binding-sid-value-ref? leafref | | | {capability-candidate-path-binding-sid}? | | +--:(srv6) | | +--ro policy-srv6-binding-sid-value-ref? leafref | | {capability-candidate-path-binding-sid}? | +--ro reason? identityref +---n sr-policy-candidate-path-binding-sid-mismatch-event +--ro policy-color-ref? | leafref +--ro policy-endpoint-ref? | leafref +--ro existing-candidate-path-protocol-origin-ref? | leafref +--ro existing-candidate-path-preference-ref? | leafref +--ro (dataplane-type)? | +--:(mpls) | | +--ro existing-candidate-path-mpls-binding-sid-value-ref? | | leafref {capability-candidate-path-binding-sid}? | +--:(srv6) | +--ro existing-candidate-path-srv6-binding-sid-value-ref? | leafref {capability-candidate-path-binding-sid}? +--ro conflicting-candidate-path-protocol-origin? Saleh, et al. Expires 7 January 2027 [Page 23] Internet-Draft YANG Data Model for SR Policy July 2026 | uint8 +--ro conflicting-candidate-path-preference? | uint32 +--ro conflicting-candidate-path-binding-sid-dataplane? | sr-policy-types:dataplane-type +--ro conflicting-candidate-path-binding-sid-value? sr-policy-types:sid-value-type Figure 2: SR Policy - YANG Tree 7. YANG Specification Following are actual YANG definition for the modules defined earlier in the document. 7.1. Types This module references [RFC9256]. file "ietf-sr-policy-types@2026-07-06.yang" module ietf-sr-policy-types { namespace "urn:ietf:params:xml:ns:yang:ietf-sr-policy-types"; prefix "sr-policy-types"; import ietf-inet-types { prefix "inet"; } import ietf-routing-types { prefix "rt-types"; } import ietf-srv6-types { prefix "srv6-types"; } organization "IETF SPRING Working Group"; contact "WG Web: WG List: Editor: Kamran Raza Editor: Tarik Saleh Editor: Zhuang Shunwan Saleh, et al. Expires 7 January 2027 [Page 24] Internet-Draft YANG Data Model for SR Policy July 2026 Editor: Satoru Matsushima Editor: Pavan Vishnu Beeram "; description "This YANG module defines the essential types for the management of SR policy module. Copyright (c) 2024 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; see the RFC itself for full legal notices."; // RFC Editor: replace XXXX with actual RFC number and remove // this note revision "2026-05-23" { description "Remove the metric type definition. The metric type from te-types will be reused instead."; reference "RFC 9256"; } revision "2025-05-22" { // RFC Editor: replace the above date 2025-05-22 with the date of // publication and remove this note. description "Add a type for MPLS SID value"; reference "RFC XXXX: YANG Data Model for Segment-routing Policy Types"; // RFC Editor: replace XXXX with actual RFC number and remove // this note } revision "2024-03-04" { // RFC Editor: replace the above date 2024-03-04 with the date of Saleh, et al. Expires 7 January 2027 [Page 25] Internet-Draft YANG Data Model for SR Policy July 2026 // publication and remove this note. description "Alignment with SR policy architecture RFC9256"; reference "RFC XXXX: YANG Data Model for Segment-routing Policy Types"; // RFC Editor: replace XXXX with actual RFC number and remove // this note } revision "2022-03-28" { description "Alignment with SR policy architecture"; reference "draft-ietf-spring-sr-policy-yang"; } revision "2019-11-04" { description "New editor added"; reference "draft-raza-spring-sr-policy-yang"; } revision "2019-07-08" { description "Dynamic TE candidate-path support"; reference "draft-raza-spring-sr-policy-yang"; } revision "2018-07-01" { description "Initial version"; reference "draft-raza-spring-sr-policy-yang"; } /* Identities */ identity candidate-path-not-selected-reason { description "Base identity for which reasons for not selecting candidate path are derived from"; } identity candidate-path-not-selected-not-best { base candidate-path-not-selected-reason; description "Higher preference path exists"; Saleh, et al. Expires 7 January 2027 [Page 26] Internet-Draft YANG Data Model for SR Policy July 2026 } identity candidate-path-not-selected-no-valid-segment-list { base candidate-path-not-selected-reason; description "Candidate path has no valid segment list(s)"; } identity candidate-path-not-selected-empty-segment-list { base candidate-path-not-selected-reason; description "Candidate path has empty segment list(s)"; } identity candidate-path-not-selected-invalid-binding-sid { base candidate-path-not-selected-reason; description "Candidate path has invalid binding SID"; } identity policy-down-reason { description "Base identity for the reasons why SR policy is operationally down"; } identity policy-down-reason-admin-down { base policy-down-reason; description "Policy is administrately down"; } identity policy-down-reason-no-source-address { base policy-down-reason; description "Policy has no source address"; } identity policy-down-reason-no-endpoint { base policy-down-reason; description "Policy has no end-point"; } identity policy-down-reason-no-candidate-path { base policy-down-reason; description "Policy has no candidate path"; } identity policy-down-reason-no-valid-candidate-path { base policy-down-reason; description "Policy has no valid candidate path"; } identity policy-down-reason-candidate-path-invalid-segment-list { base policy-down-reason; description "Policy's candidate path has invalid segment list"; } identity policy-down-reason-policy-unconfigured { base policy-down-reason; Saleh, et al. Expires 7 January 2027 [Page 27] Internet-Draft YANG Data Model for SR Policy July 2026 description "Policy is unconfigured"; } identity policy-down-reason-policy-color-endpoint-updated { base policy-down-reason; description "Policy's color and end-point are updated"; } identity policy-down-reason-local-label-setup-failed { base policy-down-reason; description "Policy's local label setup (allocation/rewrite) failed"; } identity policy-down-reason-forwarding-rewrite-failed { base policy-down-reason; description "Policy's forwarding rewrite installation failed"; } identity policy-down-reason-internal-error { base policy-down-reason; description "Infra related internal error"; } identity binding-sid-unavailable-reason { description "Base identity for binding sid unavailable reason types"; } identity binding-sid-allocation-error { base binding-sid-unavailable-reason; description "SID allocator returned an error"; } identity binding-sid-already-exists { base binding-sid-unavailable-reason; description "Binding sid already exists/allocated"; } identity binding-sid-internal-error { base binding-sid-unavailable-reason; description "Internal error with binding sid allocation"; } identity binding-sid-color-endpoint-conflict { base binding-sid-unavailable-reason; description "Binding sid already allocated by another sr-policy with different color/endpoint"; } identity binding-sid-rewrite-error { base binding-sid-unavailable-reason; description "Binding sid forwarding rewrite error"; } identity binding-sid-outside-srlb-range { base binding-sid-unavailable-reason; description "Binding sid outside SRLB range"; Saleh, et al. Expires 7 January 2027 [Page 28] Internet-Draft YANG Data Model for SR Policy July 2026 } identity segment-type { description "Base identity for the segment type"; } identity segment-type-A { base segment-type; description "SR-MPLS Label"; } identity segment-type-B { base segment-type; description "SRv6 SID"; } identity segment-type-C { base segment-type; description "IPv4 Prefix with optional SR Algorithm"; } identity segment-type-D { base segment-type; description "IPv6 Global Prefix with optional SR Algorithm for SR-MPLS"; } identity segment-type-E { base segment-type; description "IPv4 Prefix with Local Interface ID"; } identity segment-type-F { base segment-type; description "IPv4 Addresses for link endpoints as Local, Remote pair"; } identity segment-type-G { base segment-type; description "IPv6 Prefix and Interface ID for link endpoints as Local, Remote pair for SR-MPLS"; } identity segment-type-H { base segment-type; description "IPv6 Addresses for link endpoints as Local, Remote pair for SR-MPLS"; } identity segment-type-I { base segment-type; description "IPv6 Global Prefix with optional SR Algorithm for SRv6"; Saleh, et al. Expires 7 January 2027 [Page 29] Internet-Draft YANG Data Model for SR Policy July 2026 } identity segment-type-J { base segment-type; description "IPv6 Prefix and Interface ID for link endpoints as Local, Remote pair for SRv6"; } identity segment-type-K { base segment-type; description "IPv6 Addresses for link endpoints as Local, Remote pair for SRv6"; } identity protocol-origin-type { description "Base identity for originating protocol type"; } identity protocol-origin-type-pcep { base protocol-origin-type; description "PCEP used as signalling mechanism for the candidate path"; } identity protocol-origin-type-bgp { base protocol-origin-type; description "BGP used as signalling mechanism for the candidate path"; } identity protocol-origin-type-local { base protocol-origin-type; description "CLI, Yang model via Netconf, gRPC, etc used for candidate path instantiation"; } /* Typdefs */ typedef mpls-sid-value-type { type rt-types:mpls-label; description "MPLS SID value type"; } typedef sid-value-type { type union { type rt-types:mpls-label; type srv6-types:srv6-sid; } description "The SID value type"; } Saleh, et al. Expires 7 January 2027 [Page 30] Internet-Draft YANG Data Model for SR Policy July 2026 typedef binding-sid-oper-state { type enumeration { enum ALLOC-PENDING { value 1; description "SID allocation pending for Binding SID"; } enum PROGRAMMED { value 3; description "Binding SID is programmed in forwarding"; } enum CONFLICT { value 4; description "Binding SID is in-conflict state with regards to SID allocation. This also means that SID allocation is pending"; } } description "Binding SID operational state type"; } typedef policy-admin-state { type enumeration { enum UP { value 1; description "SR policy is administratively up"; } enum DOWN { value 2; description "SR policy is administratively down"; } } description "SR policy admin state"; } typedef policy-oper-state { type enumeration { enum UP { value 1; description "SR policy is operationally up"; } enum DOWN { value 2; description "SR policy is operationally down"; } } description "SR policy oper state"; } Saleh, et al. Expires 7 January 2027 [Page 31] Internet-Draft YANG Data Model for SR Policy July 2026 typedef margin-type { type enumeration { enum absolute { value 1; description "Absolute value"; } enum relative { value 2; description "Relative value"; } } description "Margin type"; } typedef dataplane-type { type enumeration { enum mpls { value 1; description "Segment-routing MPLS"; } enum srv6 { value 2; description "Segment-routing v6"; } } description "Dataplane type of the segments"; } typedef binding-sid-alloc-mode { type enumeration { enum explicit { value 1; description "Explicitly specified BSID"; } enum dynamic { value 2; description "Dynamically allocated BSID"; } } description "Binding SID allocation mode"; } typedef explicit-binding-sid-rule-type { type enumeration { enum enforce-srlb { value 1; description "Explicit Binding SID is enforced with no fallback if label does not fall in SRLB or if no SRLB is configured"; } enum fallback-dynamic { value 2; description Saleh, et al. Expires 7 January 2027 [Page 32] Internet-Draft YANG Data Model for SR Policy July 2026 "Explicit Binding SID falls back to dynamic in case explicit label is not available."; } } description "Explicit binding sid rule types"; } typedef sid-protection-eligibility-type { type enumeration { enum protected-preferred { value 1; description "Prefer protected SID"; } enum protected-only { value 2; description "Protected SID only"; } enum unprotected-preferred { value 3; description "Prefer unprotected SID"; } enum unprotected-only { value 4; description "Unprotected SID only"; } } description "Types for SID protection eligibility"; } typedef node-address-type { type inet:ipv6-address; description "Originator node address"; } typedef sid-algorithm-type { type uint8 { range "0..255"; } description "SID algorithm type"; } typedef color-type { type uint32 { range "1..4294967295"; } description "Policy color type"; } Saleh, et al. Expires 7 January 2027 [Page 33] Internet-Draft YANG Data Model for SR Policy July 2026 typedef name-type { type string { length "1..59"; } description "Policy name type"; } } Figure 3: ietf-sr-policy-types.yang 7.2. SR Policy This module references [RFC6780] and [RFC9256]. file "ietf-sr-policy@2026-07-06.yang" module ietf-sr-policy { namespace "urn:ietf:params:xml:ns:yang:ietf-sr-policy"; prefix "sr-policy"; import ietf-inet-types { prefix "inet"; } import ietf-interfaces { prefix if; } import ietf-routing { prefix "rt"; } import ietf-routing-types { prefix "rt-types"; } import ietf-yang-types { prefix "yang"; } import ietf-srv6-types { prefix "srv6-types"; } Saleh, et al. Expires 7 January 2027 [Page 34] Internet-Draft YANG Data Model for SR Policy July 2026 import ietf-sr-policy-types { prefix "sr-policy-types"; } import ietf-te-types { prefix "te-types"; } organization "IETF SPRING Working Group"; contact "WG Web: WG List: Editor: Kamran Raza Editor: Tarik Saleh Editor: Zhuang Shunwan Editor: Satoru Matsushima Editor: Vishnu Pavan Beeram "; description "This module contains a collection of YANG definitions for SR policy module. Copyright (c) 2024 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; 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."; // RFC Editor: replace XXXX with actual RFC number and remove // this note Saleh, et al. Expires 7 January 2027 [Page 35] Internet-Draft YANG Data Model for SR Policy July 2026 revision "2026-07-06" { description "Maximize reuse of optimization objectives and path constraints from te-types."; reference "RFC 8776: Common YANG Data Types for Traffic Engineering"; } revision "2026-05-23" { description "Use the path metric type from te-types."; reference "RFC 9256"; } revision "2025-10-20" { description "Add the headend-address to the policy key to ensure global uniqueness across multiple headends, consistent with RFC 9256."; reference "RFC 9256"; } revision "2025-05-22" { description "Update the SR policy YANG model with more alignment with SR policy architecture"; reference "RFC XXXX: YANG Data Model for Segment-routing Policy"; // RFC Editor: replace XXXX with actual RFC number and remove // this note } revision "2024-11-22" { description "Fix SR policy YANG model"; reference "RFC XXXX: YANG Data Model for Segment-routing Policy"; // RFC Editor: replace XXXX with actual RFC number and remove // this note } revision "2024-03-04" { description "Alignment with SR policy architecture RFC9256"; reference "RFC XXXX: YANG Data Model for Segment-routing Policy"; // RFC Editor: replace XXXX with actual RFC number and remove // this note } Saleh, et al. Expires 7 January 2027 [Page 36] Internet-Draft YANG Data Model for SR Policy July 2026 revision "2022-03-28" { description "Alignment with SR policy architecture"; reference "draft-ietf-spring-sr-policy-yang"; } revision "2019-11-04" { description "Changes in keys for policy and its candidate paths"; reference "draft-raza-spring-sr-policy-yang"; } revision "2019-07-08" { description "Dynamic TE candidate-path support"; reference "draft-raza-spring-sr-policy-yang"; } revision "2018-07-01" { description "Initial version"; reference "draft-raza-spring-sr-policy-yang"; } identity route-include-any-srlg { base te-types:route-usage-type; description "Includes a path if at least one configured SRLG value is present."; } identity route-include-all-srlg { base te-types:route-usage-type; description "Includes a path only if all configured SRLG values are present."; } identity msd { base te-types:path-metric-type; description "Maximum SID Depth (MSD) path metric type. When used in SR Policy path metric bounds, the upper-bound Saleh, et al. Expires 7 January 2027 [Page 37] Internet-Draft YANG Data Model for SR Policy July 2026 leaf carries the maximum SID depth limit."; } //TBD: To be moved to srv6-base model when the model is ready grouping srv6-sid-info { description "Define an SRv6 SID"; leaf value { type srv6-types:srv6-sid; description "SRv6 SID value"; } leaf sid-behavior { type identityref { base srv6-types:srv6-endpoint-type; } description "SRv6 BSID behavior"; } container sid-structure { description "SRv6 BSID structure"; uses srv6-types:srv6-sid-structure-grouping; } } grouping srv6-bsid-type-b-config { description "SRv6 BSID Type-B config grouping"; leaf sid-behavior { type identityref { base srv6-types:srv6-endpoint-type; } description "SRv6 BSID behavior"; } container sid-structure { description "SRv6 BSID structure"; uses srv6-types:srv6-sid-structure-grouping; } } grouping segment_config { description "Segment properties grouping"; leaf index { type uint32; description "Segment index"; } leaf type { type identityref { Saleh, et al. Expires 7 January 2027 [Page 38] Internet-Draft YANG Data Model for SR Policy July 2026 base sr-policy-types:segment-type; } mandatory true; description "Segment type"; } container sr-mpls { description "SR-MPLS specific types"; container Type-A { description "Segment declared by MPLS label"; leaf value { type rt-types:mpls-label; description "MPLS label value"; } } container Type-C { description "Segment declared by IPv4 Prefix with optional SR Algorithm for SR-MPLS"; leaf ipv4-address { type inet:ipv4-address; description "Segment IPv4 address"; } leaf algorithm { type uint8; description "Prefix SID algorithm identifier"; } } container Type-D { description "Segment declared by IPv6 Global Prefix with optional SR Algorithm for SR-MPLS"; leaf ipv6-address { type inet:ipv6-address; description "Segment IPv6 address"; } leaf algorithm { type uint8; description "Prefix SID algorithm identifier"; } } container Type-E { description Saleh, et al. Expires 7 January 2027 [Page 39] Internet-Draft YANG Data Model for SR Policy July 2026 "Segment declared by IPv4 Prefix with Local Interface ID - SR-MPLS"; leaf ipv4-address { type inet:ipv4-address; description "Node IPv4 address"; } leaf interface-identifier { type uint32; description "local interface identifier"; } } container Type-F { description "Segment declared by IPv4 Addresses for link endpoints as Local, Remote pair - SR-MPLS"; leaf local-ipv4-address { type inet:ipv4-address; description "Segment local IPv4 adjacency address"; } leaf remote-ipv4-address { type inet:ipv4-address; description "Segment remote IPv4 adjacency address"; } } container Type-G { description "Segment declared by IPv6 Prefix and Interface ID for link endpoints as Local, Remote pair for SR-MPLS"; leaf local-ipv6-address { type inet:ipv6-address; description "Local link IPv6 address"; } leaf local-interface-identifier { type uint32; description "Local interface identifier"; } leaf remote-ipv6-address { type inet:ipv6-address; description "Remote link IPv6 address"; } leaf remote-interface-identifier { type uint32; description "Remote interface identifier"; } } Saleh, et al. Expires 7 January 2027 [Page 40] Internet-Draft YANG Data Model for SR Policy July 2026 container Type-H { description "Segment declared by IPv6 Addresses for link endpoints as Local, Remote pair for SR-MPLS"; leaf local-ipv6-address { type inet:ipv6-address; description "Segment local IPv6 adjacency address"; } leaf remote-ipv6-address { type inet:ipv6-address; description "Segment remote IPv6 adjacency address"; } } } // sr-mpls container srv6 { description "SRv6 specific types"; container Type-B { description "Segment declared by SRv6 SID value"; leaf value { type srv6-types:srv6-sid; description "SRv6 SID value"; } uses srv6-bsid-type-b-config; } container Type-I { description "Segment declared by IPv6 Global Prefix with optional SR Algorithm for SRv6"; leaf ipv6-address { type inet:ipv6-address; description "Segment IPv6 prefix"; } leaf algorithm { type uint8; description "Prefix SID algorithm identifier"; } } container Type-J { description "Segment declared by IPv6 Prefix and Interface ID for link endpoints as Local, Remote pair for SRv6"; leaf local-ipv6-address { type inet:ipv6-address; Saleh, et al. Expires 7 January 2027 [Page 41] Internet-Draft YANG Data Model for SR Policy July 2026 description "Local link IPv6 address"; } leaf local-interface-identifier { type uint32; description "Local interface identifier"; } leaf remote-ipv6-address { type inet:ipv6-address; description "Remote link IPv6 address"; } leaf remote-interface-identifier { type uint32; description "Remote interface identifier"; } } container Type-K { description "Segment declared by IPv6 Addresses for link endpoints as Local, Remote pair for SRv6"; leaf local-ipv6-address { type inet:ipv6-address; description "Segment local IPv6 adjacency address"; } leaf remote-ipv6-address { type inet:ipv6-address; description "Segment remote IPv6 adjacency address"; } } } // srv6 leaf validate { type boolean; default 'false'; description "Indicates whether the segment should be validated. The default applies to all segments other than the first segment. For the first segment, validation is always done."; } } grouping segment-properties { description "SR segment properties grouping"; uses segment_config; } grouping template-path-constraints { description Saleh, et al. Expires 7 January 2027 [Page 42] Internet-Draft YANG Data Model for SR Policy July 2026 "Constraints of optimization template."; uses template-constraints-base; container ip-address { description "IP address constraints on the computed dynamic path"; leaf-list exclude { type inet:ip-address; description "Must exclude the links that has any of these IP addresses."; } } container segment-rules { description "Constraints on the segments to be used in the path"; leaf sid-protection-eligibility { type sr-policy-types:sid-protection-eligibility-type; description "SID protection eligibility"; } } } grouping optimization-templates { description "Path optimization templates properties"; container optimization-templates { description "Path optimization templates"; list optimization-template { key "color"; description "Path optimization template"; leaf color { type uint32; description "Template identifier as a policy color"; } container candidate-paths { description "A list of candidate paths representing the optimization objectives and constraints"; list candidate-path { Saleh, et al. Expires 7 January 2027 [Page 43] Internet-Draft YANG Data Model for SR Policy July 2026 key "discriminator"; description "Candidate paths representing the optimization objectives and constraints"; leaf discriminator { type uint32; description "Candidate path distinguisher"; } uses candidate-path-optimization; container constraints { description "Constraints of a path optimization template"; uses template-path-constraints; } } } } } } grouping attributes { description "Grouping containing attributes applicable to all SR policies"; container attributes { description "Attributes applicable to SR policies"; uses segment-lists; uses explicit-binding-sid-rules; } } grouping forwarding-counters { description "Grouping for counters"; container counters { config false; description "Counters containing stats related to forwarding"; leaf pkts { type yang:counter64; description "Number of packets forwarded"; } leaf octets { type yang:counter64; units "byte"; description "Number of bytes forwarded"; Saleh, et al. Expires 7 January 2027 [Page 44] Internet-Draft YANG Data Model for SR Policy July 2026 } } } grouping segment-lists { description "Segment lists grouping"; container segment-lists { description "Segment-lists properties"; list segment-list { key "name"; description "Segment-list properties"; leaf name { type string; description "Segment-list name"; } container segments { description "Segments for given segment list"; list segment { key "index"; description "Configure Segment/hop at the index"; uses segment-properties; } } } } } grouping binding-sid_config { description "Binding SID configuration properties grouping"; container mpls-sid { description "MPLS binding SIDs"; leaf value { type sr-policy-types:mpls-sid-value-type; description "MPLS binding SID value"; } } container srv6-sids { description "SRv6 binding SIDs"; list srv6-sid { key "index"; description "Configure an SRv6 binding-sid"; leaf index { Saleh, et al. Expires 7 January 2027 [Page 45] Internet-Draft YANG Data Model for SR Policy July 2026 type uint32; description "Binding SID index"; } leaf locator-name { type srv6-types:srv6-locator-name-type; description "Locator name used to allocate SRv6 binding SID"; } uses srv6-sid-info; } } } grouping binding-sid_state { description "Binding SID state properties grouping"; leaf alloc-mode { type sr-policy-types:binding-sid-alloc-mode; config false; description "Binding SID allocation mode"; } leaf allocated-sid { type sr-policy-types:sid-value-type; config false; description "Allocated SID value for the Binding SID"; } leaf oper-state { type sr-policy-types:binding-sid-oper-state; config false; description "Binding SID operational state"; } } grouping binding-sid-properties { description "Binding SID properties grouping"; container binding-sid { description "Binding Segment ID"; uses binding-sid_config; } } grouping path-forwarding_state { description "Policy Forwarding path information"; leaf path-id { type uint8; description "Primary path id"; } Saleh, et al. Expires 7 January 2027 [Page 46] Internet-Draft YANG Data Model for SR Policy July 2026 leaf next-hop-address { type inet:ip-address; description "Nexthop address"; } leaf next-hop-table-id { type uint32; description "Table ID for nexthop address"; } leaf interface { type if:interface-ref; description "Outgoing interface handle"; } leaf is-protected { type boolean; description "Is this path protected ?"; } leaf backup-path-id { type uint8; description "Backup path id"; } leaf is-pure-backup { type boolean; description "Is this path a pure backup ?"; } leaf weight { type uint32; description "Path's weight for W-ECMP balancing"; } container sid-list { description "Outgoing sid stack"; uses sid-list-grouping; } } grouping cpath-cmn-properties { description "Common properties of the candidate path"; leaf is-active { type boolean; config false; description "True if the candidate path is valid and used to forward traffic, False otherwise"; } leaf is-valid { type boolean; Saleh, et al. Expires 7 January 2027 [Page 47] Internet-Draft YANG Data Model for SR Policy July 2026 config false; description "True if at least one segment-list is valid, False otherwise"; } container computed-sid-list { config false; description "Computed SID list which could be different from outgoing SID list"; uses sid-list-grouping; } container forwarding-paths { config false; description "Forwarding state of paths"; list forwarding-path { key "path-id"; description "Forwarding path"; uses path-forwarding_state; uses forwarding-counters; } } } grouping explicit-path-properties { description "Explicit path properties of the candidate path"; container segment-lists { description "Path segment list(s) properties"; list segment-list { key "name-ref"; description "SR policy candidate path segment lists"; leaf name-ref { type leafref { path "/rt:routing/" + "sr-policy:segment-routing/" + "sr-policy:traffic-engineering/" + "sr-policy:attributes/" + "sr-policy:segment-lists/" + "sr-policy:segment-list/" + "sr-policy:name"; } description "Reference to segment-list name"; Saleh, et al. Expires 7 January 2027 [Page 48] Internet-Draft YANG Data Model for SR Policy July 2026 } leaf weight { type uint32; default 1; description "Segment-list weighted loadshare"; } leaf is-valid { type boolean; config false; description "True if the segment-list is valid, False otherwise"; } uses forwarding-counters; } } } grouping affinity-mapping { description "Affinity-map grouping"; container affinity-map { description "Mapping of affinity names to bit position"; list affinity { key "name"; unique "bit-position"; leaf name { type string; description "Name of the affinity"; } leaf bit-position { type uint16; description "The affinity entry in this list is mapped to the this bit-position in the affinity bitmap"; } description "Affinity"; } } } grouping srlg { description "SRLG grouping"; container srlgs { description "SRLG"; Saleh, et al. Expires 7 January 2027 [Page 49] Internet-Draft YANG Data Model for SR Policy July 2026 list srlg { key "name"; leaf name { type string; description "Name of the SRLG"; } leaf description { type string; description "Description of the SRLG"; } leaf value { type uint32; mandatory true; description "The associated value (for advertisements etc.) "; } description "SRLG"; } } } grouping template-constraints-base { description "Path constraints base grouping for optimization templates."; container path-constraints { description "Path constraints."; uses te-types:generic-path-metric-bounds; uses te-types:generic-path-affinities; uses te-types:generic-path-srlgs; } } grouping candidate-constraints-base { description "Path constraints base grouping for candidate paths."; container path-constraints { description "Path constraints."; Saleh, et al. Expires 7 January 2027 [Page 50] Internet-Draft YANG Data Model for SR Policy July 2026 uses te-types:generic-path-metric-bounds; uses te-types:generic-path-affinities; uses te-types:generic-path-srlgs; uses te-types:generic-path-disjointness; } } grouping candidate-path-optimization { description "Candidate-path optimization objective grouping."; container optimization-objectives { description "Optimization objectives for the dynamic path computation."; list minimize-metric { key "metric-type"; description "The metric entries for which the path is optimized. While minimize-metric is defined as a list, implementation may use only one entry. The inherited TE route-object include/exclude subtrees are not applicable in SR Policy because the TE route-object optimization identities that activate them are disallowed."; uses te-types:optimization-metric-entry { refine "metric-type" { must ". != 'te-types:path-metric-optimize-includes' and " + ". != 'te-types:path-metric-optimize-excludes'" { error-message "SR Policy minimize-metric only supports real path " + "metric identities."; description "Disallow TE route-object optimization identities used for include/exclude optimization so minimize-metric stays aligned with SR Policy semantics."; } description "Metric type for the SR Policy minimize-metric objective."; } } container margin { description Saleh, et al. Expires 7 January 2027 [Page 51] Internet-Draft YANG Data Model for SR Policy July 2026 "The margin by which two paths with similar metric-type would be considered equal."; leaf type { type sr-policy-types:margin-type; description "Margin type"; } leaf value { type uint32; description "Margin value"; } leaf computed-value { type uint32; config false; description "Computed metric value"; } } } } } grouping candidate-path-constraints { description "Candidate-path constraints grouping."; container constraints { description "Constraints for the dynamic path computation"; uses candidate-constraints-base; container ip-address { description "IP address constraints on the computed dynamic path"; leaf-list exclude { type inet:ip-address; description "Must exclude the links that has any of these IP addresses."; } leaf-list include-any { type inet:ip-address; description "Must include atleast 1 link (or possibly more) with any of these IP addresses."; } leaf-list include-all { type inet:ip-address; description Saleh, et al. Expires 7 January 2027 [Page 52] Internet-Draft YANG Data Model for SR Policy July 2026 "Must include all the links that have any of these IP addresses."; } } container segment-rules { description "Constraints on the segments to be used in the path"; leaf sid-algorithm { type sr-policy-types:sid-algorithm-type; description "The prefix-sid algorithm to be used in path calculation"; } leaf sid-protection-eligibility { type sr-policy-types:sid-protection-eligibility-type; description "SID protection eligibility"; } } container disjoint-path { when "../path-constraints/disjointness"; description "SR-specific association metadata that qualifies the TE disjointness constraint."; leaf association-group-id { type uint16; mandatory true; description "Association group Id"; } leaf association-source { type inet:ip-address; mandatory true; description "Association source address"; } leaf association-extended-id { type yang:hex-string; description "Association extended identifier."; reference "RFC6780"; } Saleh, et al. Expires 7 January 2027 [Page 53] Internet-Draft YANG Data Model for SR Policy July 2026 } } } grouping dynamic-path-properties { description "Dynamic path properties of the candidate path"; container segment-list { description "Segment-list properties"; leaf segment-list-dataplane-type { type sr-policy-types:dataplane-type; mandatory true; description "The dataplane type for the segment-list"; } leaf is-valid { type boolean; config false; description "True if the segment-list is valid, False otherwise"; } uses forwarding-counters; } uses candidate-path-optimization; uses candidate-path-constraints; } grouping composite-path-properties { description "Composite path properties of the candidate path"; container constituent-policies { description "Constituent SR policies"; list constituent-policy { key "color"; description "List of constituent SR policies"; leaf color { type sr-policy-types:color-type; description "Color associated with the constituent policy (the endpoint is same as the parent policy)"; } leaf weight { type uint32; default 1; Saleh, et al. Expires 7 January 2027 [Page 54] Internet-Draft YANG Data Model for SR Policy July 2026 description "Constituent policy weighted loadshare"; } } } } grouping mpls-label-stack { description "Grouping for MPLS label stack"; list labels { key "index"; description "Stack containing MPLS labels"; leaf index { type uint32; description "A unique ID of an MPLS label in labels list"; } leaf label { type rt-types:mpls-label; description "MPLS label value"; } } } grouping srv6-sid-stack { description "Grouping for SRv6 label stack"; list sids { key "index"; description "Stack containing SRv6 SIDs"; leaf index { type uint32; description "A unique ID of an SRv6 sid in sid list"; } leaf sid { type srv6-types:srv6-sid; description "SRv6 sid value"; } } } Saleh, et al. Expires 7 January 2027 [Page 55] Internet-Draft YANG Data Model for SR Policy July 2026 grouping sid-list-grouping { description "Grouping for SID list"; choice dataplane-type { description "Outgoing sids dataplane choice"; case mpls { uses mpls-label-stack; } case srv6 { uses srv6-sid-stack; } } } grouping candidate-path_state { description "Candidate path state properties grouping"; leaf is-best-candidate-path { type boolean; default 'false'; config false; description "True if the candidate path is the best candidate path, False otherwise"; } leaf non-selection-reason { type identityref { base sr-policy-types:candidate-path-not-selected-reason; } config false; description "Candidate path not selected reason"; } } grouping policy-properties_config { description "SR policy configuration grouping"; leaf name { type sr-policy-types:name-type; description "SR policy name"; } leaf headend { type inet:ip-address; description "The IP address identifying the SR Policy headend node. This addition ensures global uniqueness of the policy key Saleh, et al. Expires 7 January 2027 [Page 56] Internet-Draft YANG Data Model for SR Policy July 2026 across multiple headends"; reference "RFC 9256: Section 2.1 - Identification of an SR Policy."; } leaf color { type sr-policy-types:color-type; description "Color associated with the policy"; } leaf endpoint { type inet:ip-address; description "Policy end point IP address"; } leaf description { type string; description "Description of the policy"; } leaf admin-state { type sr-policy-types:policy-admin-state; default 'UP'; description "SR policy administrative state, true for enabled, false for disabled"; } leaf priority { type uint8; default 128; description "Priority considered when policy is recomputed due to topology changes"; } leaf profile-id { type uint32; description "A profile represents a set of configuration knobs specifying a policy or candidate-path attributes. The profile-ID feature allows usage of vendor/implementation specific functionality per policy without requiring explicit support by controller."; } container bandwidth { description "Bandwidth constraints"; leaf requested { type te-types:te-bandwidth; description "Requested bandwidth expressed in bytes per second"; } Saleh, et al. Expires 7 January 2027 [Page 57] Internet-Draft YANG Data Model for SR Policy July 2026 leaf reserved { type te-types:te-bandwidth; config false; description "Reserved bandwidth expressed in bytes per second"; } } } grouping policy-properties_state { description "SR policy property grouping"; leaf oper-state { type sr-policy-types:policy-oper-state; config false; description "SR policy operational state"; } leaf transition-count { type uint32; config false; description "Indicates number of up/down transitions"; } leaf up-time { type yang:date-and-time; config false; description "Policy up time in seconds"; } leaf down-time { type yang:date-and-time; config false; description "Policy down time in seconds"; } } grouping policy-properties { description "SR policy properties"; uses policy-properties_config; uses policy-properties_state; uses binding-sid-properties; uses forwarding-counters; } grouping candidate-path-type { description "Candidate path type grouping"; choice type { description "Type of candidate paths"; Saleh, et al. Expires 7 January 2027 [Page 58] Internet-Draft YANG Data Model for SR Policy July 2026 case explicit { description "Candidate path with explicitly defined set/s of segment-lists"; uses explicit-path-properties; } case dynamic { description "Candidate path with dynamic computed segment-lists"; uses dynamic-path-properties; } case composite { description "Candidate path that groups SR policies each with explicit and/or dynamic candidate path with potentially different optimization objectives and constraints"; uses composite-path-properties; } } } grouping candidate-paths { description "SR policy candidate path grouping"; container candidate-paths { description "SR policy candidate path(s) "; list candidate-path { key "protocol-origin originator-asn originator-node-address discriminator"; unique "preference"; description "SR policy Candidate path(s) list entry"; leaf protocol-origin { type identityref { base sr-policy-types:protocol-origin-type; } description "Instantiation mechanism used to create the candidate path"; } leaf originator-asn { type uint32; description "The autonomous system number (ASN) of the provisioning node. If 2-byte ASNs are in use, the low-order 16 bits MUST be used, and the high-order bits MUST be set to 0"; Saleh, et al. Expires 7 January 2027 [Page 59] Internet-Draft YANG Data Model for SR Policy July 2026 } leaf originator-node-address { type sr-policy-types:node-address-type; description "represented as a 128-bit value. IPv4 addresses MUST be encoded in the lowest 32 bits, and the high-order bits MUST be set to 0"; } leaf discriminator { type uint32; description "Candidate path distinguisher"; } leaf preference { type uint32 { range "1..65535"; } mandatory true; description "Candidate path preference"; } leaf name { type string; description "Candidate path name"; } leaf description { type string; description "Candidate path description"; } leaf drop-upon-invalid { type boolean; description "Enable traffic dropping when LSP is invalid"; } leaf admin-state { type boolean; description "Shutdown the candidate-path"; } container binding-sid { if-feature capability-candidate-path-binding-sid; description "Binding segment ID"; uses binding-sid_config; } uses candidate-path-type; uses candidate-path_state; uses cpath-cmn-properties; } } } Saleh, et al. Expires 7 January 2027 [Page 60] Internet-Draft YANG Data Model for SR Policy July 2026 grouping policies { description "SR policy grouping"; container policies { description "SR Policy container"; list policy { key "headend color endpoint"; unique "name"; description "List of SR Policies. Each SR Policy is uniquely identified by the tuple globally, as defined in RFC 9256. The headend identifies the ingress node that instantiates or owns this policy."; uses policy-properties; uses candidate-paths; } } } grouping explicit-binding-sid-rules { description "Grouping for explicit binding sid rules"; list explicit-binding-sid-rules { key "index"; description "Explicit binding sid rules applicable for all policies"; leaf index { type uint32; description "Explicit binding SID rules list index"; } leaf rule { type sr-policy-types:explicit-binding-sid-rule-type; mandatory true; description "Explicit binding sid rule"; } } } augment "/rt:routing" { description "This augments routing-instance configuration with segment-routing sr-policy."; container segment-routing { description "Main segment routing container"; container traffic-engineering { description "Traffic-engineering container"; Saleh, et al. Expires 7 January 2027 [Page 61] Internet-Draft YANG Data Model for SR Policy July 2026 uses optimization-templates; uses attributes; uses policies; } } } augment "/rt:routing/" + "sr-policy:segment-routing/" + "sr-policy:traffic-engineering/" + "sr-policy:policies/" + "sr-policy:policy/" + "sr-policy:binding-sid/" + "sr-policy:mpls-sid" { description "Augments binding-sid state with MPLS binding-sid"; uses binding-sid_state; } augment "/rt:routing/" + "sr-policy:segment-routing/" + "sr-policy:traffic-engineering/" + "sr-policy:policies/" + "sr-policy:policy/" + "sr-policy:binding-sid/" + "sr-policy:srv6-sids/" + "sr-policy:srv6-sid" { description "Augments binding-sid state with SRv6 binding-sid"; uses binding-sid_state; } /* Notifications */ notification sr-policy-oper-state-change-event { description "Notification event when the operational state of the SR policy changes"; leaf policy-name-ref { type leafref { path "/rt:routing/" + "sr-policy:segment-routing/" + "sr-policy:traffic-engineering/" + "sr-policy:policies/" + "sr-policy:policy/" + "sr-policy:name"; } Saleh, et al. Expires 7 January 2027 [Page 62] Internet-Draft YANG Data Model for SR Policy July 2026 description "Reference to sr-policy name"; } leaf policy-color-ref { type leafref { path "/rt:routing/" + "sr-policy:segment-routing/" + "sr-policy:traffic-engineering/" + "sr-policy:policies/" + "sr-policy:policy/" + "sr-policy:color"; } description "Reference to sr-policy color"; } leaf policy-endpoint-ref { type leafref { path "/rt:routing/" + "sr-policy:segment-routing/" + "sr-policy:traffic-engineering/" + "sr-policy:policies/" + "sr-policy:policy/" + "sr-policy:endpoint"; } description "Reference to sr-policy endpoint"; } leaf policy-new-oper-state { type sr-policy-types:policy-oper-state; description "New operational state of the SR policy"; } leaf policy-down-reason { type identityref { base sr-policy-types:policy-down-reason; } description "Down reason if the SR policy's new operational state is down"; } } notification sr-policy-candidate-path-change-event { description "Notification event when candidate path changes for SR policy"; leaf policy-name-ref { type leafref { Saleh, et al. Expires 7 January 2027 [Page 63] Internet-Draft YANG Data Model for SR Policy July 2026 path "/rt:routing/" + "sr-policy:segment-routing/" + "sr-policy:traffic-engineering/" + "sr-policy:policies/" + "sr-policy:policy/" + "sr-policy:name"; } description "Reference to sr-policy name"; } leaf policy-color-ref { type leafref { path "/rt:routing/" + "sr-policy:segment-routing/" + "sr-policy:traffic-engineering/" + "sr-policy:policies/" + "sr-policy:policy/" + "sr-policy:color"; } description "Reference to sr-policy color"; } leaf policy-endpoint-ref { type leafref { path "/rt:routing/" + "sr-policy:segment-routing/" + "sr-policy:traffic-engineering/" + "sr-policy:policies/" + "sr-policy:policy/" + "sr-policy:endpoint"; } description "Reference to sr-policy endpoint"; } leaf existing-preference { type uint32; description "Existing candidate path preference"; } leaf new-preference { type uint32; description "New candidate path preference"; } } notification sr-policy-binding-sid-unavailable-event { description "Notification event when the binding sid of sr-policy is Saleh, et al. Expires 7 January 2027 [Page 64] Internet-Draft YANG Data Model for SR Policy July 2026 unavailable"; leaf policy-name-ref { type leafref { path "/rt:routing/" + "sr-policy:segment-routing/" + "sr-policy:traffic-engineering/" + "sr-policy:policies/" + "sr-policy:policy/" + "sr-policy:name"; } description "Reference to sr-policy name"; } leaf policy-color-ref { type leafref { path "/rt:routing/" + "sr-policy:segment-routing/" + "sr-policy:traffic-engineering/" + "sr-policy:policies/" + "sr-policy:policy/" + "sr-policy:color"; } description "Reference to sr-policy color"; } leaf policy-endpoint-ref { type leafref { path "/rt:routing/" + "sr-policy:segment-routing/" + "sr-policy:traffic-engineering/" + "sr-policy:policies/" + "sr-policy:policy/" + "sr-policy:endpoint"; } description "Reference to sr-policy endpoint"; } choice dataplane-type { description "Binding SID dataplane choice"; case mpls { leaf policy-mpls-binding-sid-value-ref { if-feature capability-candidate-path-binding-sid; type leafref { path "/rt:routing/" + "sr-policy:segment-routing/" + "sr-policy:traffic-engineering/" Saleh, et al. Expires 7 January 2027 [Page 65] Internet-Draft YANG Data Model for SR Policy July 2026 + "sr-policy:policies/" + "sr-policy:policy/" + "sr-policy:binding-sid/" + "sr-policy:mpls-sid/" + "sr-policy:value"; } description "Reference to sr-policy MPLS binding SID value"; } } case srv6 { leaf policy-srv6-binding-sid-value-ref { if-feature capability-candidate-path-binding-sid; type leafref { path "/rt:routing/" + "sr-policy:segment-routing/" + "sr-policy:traffic-engineering/" + "sr-policy:policies/" + "sr-policy:policy/" + "sr-policy:binding-sid/" + "sr-policy:srv6-sids/" + "sr-policy:srv6-sid/" + "sr-policy:value"; } description "Reference to sr-policy SRv6 binding SID value"; } } } leaf reason { type identityref { base sr-policy-types:binding-sid-unavailable-reason; } description "Reason why the binding sid is unavailable"; } } notification sr-policy-candidate-path-binding-sid-mismatch-event { description "Notification event when binding sid of requested candidate path is different from the binding sid of the existing candidate path"; leaf policy-color-ref { type leafref { path "/rt:routing/" + "sr-policy:segment-routing/" + "sr-policy:traffic-engineering/" Saleh, et al. Expires 7 January 2027 [Page 66] Internet-Draft YANG Data Model for SR Policy July 2026 + "sr-policy:policies/" + "sr-policy:policy/" + "sr-policy:color"; } description "Reference to sr-policy color"; } leaf policy-endpoint-ref { type leafref { path "/rt:routing/" + "sr-policy:segment-routing/" + "sr-policy:traffic-engineering/" + "sr-policy:policies/" + "sr-policy:policy/" + "sr-policy:endpoint"; } description "Reference to sr-policy endpoint"; } leaf existing-candidate-path-protocol-origin-ref { type leafref { path "/rt:routing/" + "sr-policy:segment-routing/" + "sr-policy:traffic-engineering/" + "sr-policy:policies/" + "sr-policy:policy/" + "sr-policy:candidate-paths/" + "sr-policy:candidate-path/" + "sr-policy:protocol-origin"; } description "Reference to existing candidate path protocol origin"; } leaf existing-candidate-path-preference-ref { type leafref { path "/rt:routing/" + "sr-policy:segment-routing/" + "sr-policy:traffic-engineering/" + "sr-policy:policies/" + "sr-policy:policy/" + "sr-policy:candidate-paths/" + "sr-policy:candidate-path/" + "sr-policy:preference"; } description "Reference to existing candidate path preference"; } Saleh, et al. Expires 7 January 2027 [Page 67] Internet-Draft YANG Data Model for SR Policy July 2026 choice dataplane-type { description "Binding SID dataplane choice"; case mpls { leaf existing-candidate-path-mpls-binding-sid-value-ref { if-feature capability-candidate-path-binding-sid; type leafref { path "/rt:routing/" + "sr-policy:segment-routing/" + "sr-policy:traffic-engineering/" + "sr-policy:policies/" + "sr-policy:policy/" + "sr-policy:candidate-paths/" + "sr-policy:candidate-path/" + "sr-policy:binding-sid/" + "sr-policy:mpls-sid/" + "sr-policy:value"; } description "Reference to existing candidate path MPLS binding SID " + "value"; } } case srv6 { leaf existing-candidate-path-srv6-binding-sid-value-ref { if-feature capability-candidate-path-binding-sid; type leafref { path "/rt:routing/" + "sr-policy:segment-routing/" + "sr-policy:traffic-engineering/" + "sr-policy:policies/" + "sr-policy:policy/" + "sr-policy:candidate-paths/" + "sr-policy:candidate-path/" + "sr-policy:binding-sid/" + "sr-policy:srv6-sids/" + "sr-policy:srv6-sid/" + "sr-policy:value"; } description "Reference to existing candidate path SRv6 binding SID " + "value"; } } } leaf conflicting-candidate-path-protocol-origin { type uint8; Saleh, et al. Expires 7 January 2027 [Page 68] Internet-Draft YANG Data Model for SR Policy July 2026 description "Conflicting candidate path protocol origin"; } leaf conflicting-candidate-path-preference { type uint32; description "Conflicting candidate path preference"; } leaf conflicting-candidate-path-binding-sid-dataplane { type sr-policy-types:dataplane-type; description "Conflicting candidate path binding sid dataplane type"; } leaf conflicting-candidate-path-binding-sid-value { type sr-policy-types:sid-value-type; description "Conflicting candidate path binding sid value"; } } /* Features */ feature capability-candidate-path-binding-sid { description "This feature enables the capability of specifying binding-sid for a candidate path."; } } Figure 4: ietf-sr-policy.yang 8. Security Considerations The YANG modules defined in this document are designed to be accessed via YANG-based management protocols, such as NETCONF [RFC6241] and RESTCONF [RFC8040]. The Network Configuration Access Control Model (NACM) [RFC8341] provides the means to restrict access for particular NETCONF or RESTCONF users to a preconfigured subset of the protocol operations and content. Saleh, et al. Expires 7 January 2027 [Page 69] Internet-Draft YANG Data Model for SR Policy July 2026 The "ietf-sr-policy-types" module defines reusable identities, typedefs, and groupings. By itself, it does not define configuration or state data nodes, RPCs, actions, or notifications. As such, it does not by itself create additional security concerns beyond those that apply to modules that reuse these definitions. The "ietf-sr-policy" module defines writable configuration data under /rt:routing/sr-policy:segment-routing/traffic-engineering. These writable data nodes are likely to be reasonably sensitive or vulnerable in some network environments. Write or delete access to these nodes without proper protection can change the path that traffic follows, redirect traffic, black-hole traffic, or disrupt service. The following writable subtrees have particular sensitivities: * /rt:routing/sr-policy:segment-routing/traffic-engineering/ optimization-templates * /rt:routing/sr-policy:segment-routing/traffic-engineering/ attributes/segment-lists * /rt:routing/sr-policy:segment-routing/traffic-engineering/ attributes/explicit-binding-sid-rules * /rt:routing/sr-policy:segment-routing/traffic-engineering/ policies Some of the readable data nodes and notifications in the "ietf-sr- policy" module may also be considered sensitive or vulnerable in some network environments because they expose policy identifiers, endpoints, candidate-path selection state, segment list contents, binding SID values, and failure reasons. In particular, read access to the operational state under /rt:routing/sr-policy:segment-routing/ traffic-engineering/policies and to the notifications sr-policy-oper- state-change-event, sr-policy-candidate-path-change-event, sr-policy- binding-sid-unavailable-event, and sr-policy-candidate-path-binding- sid-mismatch-event should be controlled. The YANG modules in this document do not define any RPC or action operations. 9. IANA Considerations This document requests the registration of the following URIs in the IETF "XML registry" [RFC3688]: Saleh, et al. Expires 7 January 2027 [Page 70] Internet-Draft YANG Data Model for SR Policy July 2026 +==================================================+==========+===+ | URI |Registrant|XML| +==================================================+==========+===+ | urn:ietf:params:xml:ns:yang:ietf-sr-policy-types |The IESG |N/A| +--------------------------------------------------+----------+---+ +--------------------------------------------------+----------+---+ | urn:ietf:params:xml:ns:yang:ietf-sr-policy |The IESG |N/A| +--------------------------------------------------+----------+---+ Table 3 This document requests the registration of the following YANG modules in the "YANG Module Names" registry [RFC7950]: +========+===================================+=========+===========+ |Name | Namespace | Prefix | Reference | +========+===================================+=========+===========+ |ietf-sr-| urn:ietf:params:xml:ns:yang:ietf- | sr- | This | |policy- | sr-policy-types | policy- | document | |types | | types | | +--------+-----------------------------------+---------+-----------+ +--------+-----------------------------------+---------+-----------+ |ietf-sr-| urn:ietf:params:xml:ns:yang:ietf- | sr- | This | |policy | sr-policy | policy | document | +--------+-----------------------------------+---------+-----------+ Table 4 10. Acknowledgments The authors of this document/YANG model would like to acknowledge the contributions/reviews by Johnson Thomas, Clarence Filsfils, Siva Sivabalan, Tarek Saad, Kris Michielsen, Dhanendra Jain, Ketan Talaulikar, Bhupendra Yadav, and Bruno Decraene. 11. References 11.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, . Saleh, et al. Expires 7 January 2027 [Page 71] Internet-Draft YANG Data Model for SR Policy July 2026 [RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., and A. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, . [RFC6780] Berger, L., Le Faucheur, F., and A. Narayanan, "RSVP ASSOCIATION Object Extensions", RFC 6780, DOI 10.17487/RFC6780, October 2012, . [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013, . [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8294] Liu, X., Qu, Y., Lindem, A., Hopps, C., and L. Berger, "Common YANG Data Types for the Routing Area", RFC 8294, DOI 10.17487/RFC8294, December 2017, . [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, . [RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, March 2018, . [RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K., and R. Wilton, "Network Management Datastore Architecture (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018, . [RFC8343] Bjorklund, M., "A YANG Data Model for Interface Management", RFC 8343, DOI 10.17487/RFC8343, March 2018, . Saleh, et al. Expires 7 January 2027 [Page 72] Internet-Draft YANG Data Model for SR Policy July 2026 [RFC8349] Lhotka, L., Lindem, A., and Y. Qu, "A YANG Data Model for Routing Management (NMDA Version)", RFC 8349, DOI 10.17487/RFC8349, March 2018, . [RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L., Decraene, B., Litkowski, S., and R. Shakir, "Segment Routing Architecture", RFC 8402, DOI 10.17487/RFC8402, July 2018, . [RFC8407] Bierman, A., "Guidelines for Authors and Reviewers of Documents Containing YANG Data Models", RFC 8407, DOI 10.17487/RFC8407, October 2018, . [RFC9256] Filsfils, C., Talaulikar, K., Ed., Voyer, D., Bogdanov, A., and P. Mattes, "Segment Routing Policy Architecture", RFC 9256, DOI 10.17487/RFC9256, July 2022, . 11.2. Informative References [I-D.ietf-idr-segment-routing-te-policy] Previdi, S., Filsfils, C., Talaulikar, K., Mattes, P., and D. Jain, "Advertising Segment Routing Policies in BGP", Work in Progress, Internet-Draft, draft-ietf-idr-segment- routing-te-policy-26, 23 October 2023, . [I-D.ietf-spring-srv6-yang] Raza, S. K., Rajamanickam, J., Matsushima, S., Yu, P., and X. Liu, "YANG Data Model for SRv6 Base and Static", Work in Progress, Internet-Draft, draft-ietf-spring-srv6-yang- 05, 7 July 2025, . [I-D.ietf-teas-rfc8776-update] Busi, I., Guo, A., Liu, X., Saad, T., and I. Bryskin, "Common YANG Data Types for Traffic Engineering", Work in Progress, Internet-Draft, draft-ietf-teas-rfc8776-update- 24, 12 June 2026, . [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, . Saleh, et al. Expires 7 January 2027 [Page 73] Internet-Draft YANG Data Model for SR Policy July 2026 Appendix A. Contributors Robert Sawaya Cisco Systems Email: rsawaya@cisco.com Daniel Voyer Individual Email: danvoyerwork@gmail.com Muhammad Durrani Oracle Corporation Muahmmad.durrani@oracle.com Authors' Addresses Tarik Saleh (editor) Cisco Systems Email: tasaleh@cisco.com Kamran Raza Cisco Systems Email: skraza@cisco.com Zhuang Shunwan Huawei Technologies Email: zhuangshunwan@huawei.com Satoru Matsushima SoftBank Email: satoru.matsushima@g.softbank.co.jp Vishnu Pavan Beeram Juniper Networks Email: vbeeram@juniper.net Saleh, et al. Expires 7 January 2027 [Page 74]