SPRING Working Group K. Raza Internet-Draft J. Rajamanickam Intended status: Standards Track Cisco Systems Expires: 8 January 2026 S. Matsushima SoftBank P. Yu Huawei Technologies X. Liu Individual 7 July 2025 YANG Data Model for SRv6 Base and Static draft-ietf-spring-srv6-yang-05 Abstract This document describes a YANG data model for Segment Routing IPv6 (SRv6) base. The model serves as a base framework for configuring and managing an SRv6 subsystem and expected to be augmented by other SRv6 technology models accordingly. Additionally, this document also specifies the model for the SRv6 Static application. The YANG modules in this document conform to the Network Management Datastore Architecture (NMDA). 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 8 January 2026. Copyright Notice Copyright (c) 2025 IETF Trust and the persons identified as the document authors. All rights reserved. Raza, et al. Expires 8 January 2026 [Page 1] Internet-Draft YANG Data Model for SRv6 July 2025 This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/ license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Specification of Requirements . . . . . . . . . . . . . . . . 3 3. SRv6 SID Building Blocks . . . . . . . . . . . . . . . . . . 3 3.1. SID Structure . . . . . . . . . . . . . . . . . . . . . . 4 3.2. SID Compression . . . . . . . . . . . . . . . . . . . . . 4 3.3. SID Format . . . . . . . . . . . . . . . . . . . . . . . 4 3.4. SID Allocation . . . . . . . . . . . . . . . . . . . . . 4 3.4.1. Uncompressed . . . . . . . . . . . . . . . . . . . . 5 3.4.2. Compressed (CSID) . . . . . . . . . . . . . . . . . . 5 4. YANG Model . . . . . . . . . . . . . . . . . . . . . . . . . 7 4.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 7 4.2. SRv6 Types . . . . . . . . . . . . . . . . . . . . . . . 8 4.3. SRv6 Base . . . . . . . . . . . . . . . . . . . . . . . . 9 4.3.1. Configuration . . . . . . . . . . . . . . . . . . . . 9 4.3.2. State . . . . . . . . . . . . . . . . . . . . . . . . 12 4.3.3. Notification . . . . . . . . . . . . . . . . . . . . 14 4.4. SRv6 Static . . . . . . . . . . . . . . . . . . . . . . . 15 4.4.1. Configuration . . . . . . . . . . . . . . . . . . . . 15 4.4.2. State . . . . . . . . . . . . . . . . . . . . . . . . 21 4.4.3. Notification . . . . . . . . . . . . . . . . . . . . 21 5. Pending Items . . . . . . . . . . . . . . . . . . . . . . . . 21 6. YANG Specification . . . . . . . . . . . . . . . . . . . . . 21 6.1. SRv6 Types . . . . . . . . . . . . . . . . . . . . . . . 21 6.2. SRv6 Base . . . . . . . . . . . . . . . . . . . . . . . . 53 6.3. SRv6 Static . . . . . . . . . . . . . . . . . . . . . . . 75 7. Security Considerations . . . . . . . . . . . . . . . . . . . 98 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 99 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 100 9.1. Normative References . . . . . . . . . . . . . . . . . . 100 9.2. Informative References . . . . . . . . . . . . . . . . . 102 Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . 103 Appendix B. Contributors . . . . . . . . . . . . . . . . . . . . 103 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 104 Raza, et al. Expires 8 January 2026 [Page 2] Internet-Draft YANG Data Model for SRv6 July 2025 1. Introduction The Network Configuration Protocol (NETCONF) [RFC6241] is one of the network management protocols that defines mechanisms to manage network devices. YANG [RFC6020] is a modular language that represents data structures in an XML tree format, and is used as a data modeling language for the NETCONF. Segment Routing (SR), as defined in [RFC8402], leverages the source routing paradigm where a node steers a packet through an ordered list of instructions, called segments. SR, thus, allows enforcing a flow through any topological path and/or service chain while maintaining per-flow state only at the ingress nodes to the SR domain. When applied to ipv6 data-plane (i.e. SRv6), SR requires a type of routing header (SRH) in an IPv6 packet that is used to encode an ordered list of IPv6 addresses (SIDs). The active segment is indicated by the Destination Address of the packet, and the next segment is indicated by a pointer in the SRH [RFC8754]. The various functions and behaviors corresponding to network programming using SRv6 are specified in [RFC8986]. This document introduces a YANG data model for base SRv6 that would serve as a base framework for configuring and managing an SRv6 subsystem. As needed, other SRv6 technology models (e.g. ISIS, OSPFv3, BGP, EVPN, Service Chaining) may augment this model. Furthermore, to illustrate basic behaviors as captured in [RFC8986], this document also specifies a YANG model for the SRv6-Static application. The model currently defines the following constructs that are used for managing SRv6: * Configuration * Operational State * Notifications 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. SRv6 SID Building Blocks Raza, et al. Expires 8 January 2026 [Page 3] Internet-Draft YANG Data Model for SRv6 July 2025 3.1. SID Structure SRv6 network programming [RFC8986] defines SRv6 SID as consisting of LOC:FUNCT:ARG (Locator:Function:Argument), where a LOC may futher be represented as B:N (SID-block:Node-Identifier). Thus, structure of an SRv6 SID is specified in terms of LBL (Locator Block Length), LNL (Locator Node Length), FL (Function Length), and AL (Argument Length). 3.2. SID Compression With respect to encoding SRv6 segment(s) in an IPv6 address (aka SID container), SRv6 SIDs can be categorized into following two main types: * Uncompressed SID * Compressed SID (CSID) In SRv6 [uncompressed] SID type, as defined in SRv6 network programming [RFC8986], a SID container (IPv6 address) contains only a single segment. Whereas, in a compressed SID (CSID) type, a SID container may contain one or more segments. The CSID types help reduce the size of SRv6 encapsulation, e.g. in the presence of long segment lists, and are defined in [RFC9800] with NEXT-CSID and REPLACE-CSID flavours. 3.3. SID Format Within each of the above mentioned SID compression types, different variant of SID structures further categorize in the sub-types - e.g. NEXT-CSID with 32 bit block and 16 bit segment (LBL=32, LNL=16, FL=16), REPLACE-CSID with 32 bit block and 32 bit segment (LBL=32, LNL=32, FL=32). In essence, a SID strucutre defines a specific format and hence we term it as a "SID Format". For ease of use, a SID format can be assigned an identity (e.g. name) and referenced using it - e.g. NEXT-CSID with LBL=32 LNL=16 FL=16 can be simply termed srv6-sid-fmt-cnext-3216. 3.4. SID Allocation The following sections highlight some important manageability items with respect to SID allocation with SID format. Raza, et al. Expires 8 January 2026 [Page 4] Internet-Draft YANG Data Model for SRv6 July 2025 3.4.1. Uncompressed The scope of the allocation space is Per-locator for an uncompressed SID type. This means that an allocated FUNCT value (e.g. 0xF000) in a locator1 would be bound to an endpoint behavior different than the same FUNCT value allocated in a locator2. In other words, a unique allocated SID is represented as LOC:FUNCT (i.e. B:N:FUNCT). The SID ID (allocation) space can be partitioned into Dynamic and Explicit allocation blocks. Though the default order and the size of these blocks is an implementation choice, the YANG model should provide ability to change these parameters. 3.4.2. Compressed (CSID) The scope of the allocation space is Per-SIDBlock (instead of Per -Locator) for a compressed SID. Assuming locator1 under SID block1 and locator2 under SID block2, an allocated FUNCT value (e.g. 0xF000) in a locator1 (SID block1) would be bound to an endpoint behavior different than the same FUNCT value allocated under locator2 (SID block2). However, if both locator1 and locator2 share the same SID block, then the allocated FUNCT value (and endpoint behavior bound to it) is also shared across locators. In other words, a unique allocated SID is represented as B:FUNCT where B is the SID Block. The compressed SID architecure paritions the SID allocation space into two: * Global ID Block (GIB): The GIB space is shared among all SR segment endpoint nodes and is used for allocations of global segments (such as SIDs that identify a node). * Local ID Block (LIB): The LIB space is unique per node and is used for allocations of local segments (such as SIDs that identify adjacency, services, etc. at the node). Since this is not a shared space, a node can fully utilize the entire LIB space without consideration of assignments at other nodes. In SID allocation space, the LIB space follows the GIB space. The following figure shows CSID allocation space and IDs: Raza, et al. Expires 8 January 2026 [Page 5] Internet-Draft YANG Data Model for SRv6 July 2025 +------------------------------+ id 0 | | Gs . . . | | . . . | GIB | . . . | | . . . | | Ge +------------------------------+ . . . | | Ls . . . | LIB | . . . | | id N | | Le +------------------------------+ Figure 1: CSID GIB/LIB Space In the above figure, the Gs and Ge refer to "GIB start" and "GIB end" indexes, whereas the Ls and Le refer to "LIB start" and "LIB end" indexes. For 16 bit CSID, Id range is 0x0000-0xffff, where Gs and Le are fixed at Id 0x0000 and 0xffff respectively. The implementations may decide default sizes for their GIB and LIB partitions. However, the YANG model should provide ability to change the partition size of the LIB in order to shrink or expand it, thus conversely expanding or shrinking GIB paritition. It is advisable to reserve a block of Ids at the bottom of CSID LIB space for advanced use cases for future use. We can term it as RLIB (Reserved LIB) partition. The implementations may decide default size for RLIB partition. The YANG mode should provide ability to change the partition size of the RLIB in order to shrink or expand it. The remaining (non-reserved) LIB space should also be partitioned into Dynamic and Explicit CSID allocation blocks. The order of the blocks is left upto the implementations - i.e. Dynamic block followed by Explicit block, or vice versa. The implementations may also decide default sizes for their Dynamic LIB and Explicit LIB blocks. However, the YANG model should provide ability to change the block size of the explicit LIB (in order to shrink or expand it), and as well as the start of the explicit LIB block. The following figure further expands the Figure 1 to illustrate LIB space partitions. Raza, et al. Expires 8 January 2026 [Page 6] Internet-Draft YANG Data Model for SRv6 July 2025 . . | . . . . . . GIB . . . . . . | | | +------------------------------+ ^ Ls | | LDs | | | | | Dynamic LIB | | | | | | | | | | | | | LDe | +------------------------------+ | | LEs LIB | | | Explicit LIB | | | | | | | LEe | +------------------------------+ | | | LRs | | Reserved LIB | | Le | | LRe v +------------------------------+ Figure 2: CSID LIB Space parititions In the above figure, the LDs and LDe refer to "Dynamic LIB start" and "Dynamic LIB end" indexes, the LEs and LEe refer to "Explicit LIB start" and "Explicit LIB end" indexes, and the LRs and LRe refer to "Reserved LIB start" and "Reserved LIB end" indexes. It goes without saying that LDs is same as Ls and LRe is same as Le. In the above Figure, Explicit partition follows Dynamic partition. A similar illustration and explanation can be laid out where Dynamic partition follows Explicit partition. 4. YANG Model 4.1. Overview This document defines following three new YANG modules: * ietf-srv6-types: defines common and basic types related to SRv6 * ietf-srv6-base: specifies management model for SRv6 base constructs (locator, SIDs, etc.) Raza, et al. Expires 8 January 2026 [Page 7] Internet-Draft YANG Data Model for SRv6 July 2025 * ietf-srv6-static: specifies management model for SRv6-static application The modeling in this document complies with the Network Management Datastore Architecture (NMDA) defined in [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. In this document, when a simplified graphical representation of YANG model is presented in a tree diagram, the meaning of the symbols in these tree diagrams is defined in [RFC8340]. 4.2. SRv6 Types SRv6 common types and definitions are defined in the new module "ietf-srv6-types". The main types defined in this module include: * Locator: - srv6-locator-name-type: SRv6 locator name - srv6-locator-len: SRv6 locator prefix length - srv6-locator-block-len: Block length in a SRv6 locator prefix - srv6-locator-node-len: Node-id field length in an SRv6 locator prefix * SID: - srv6-sid: SRv6 SID - srv6-sid-func-len: FUNCT field length of an SRv6 SID - srv6-sid-arg-len: ARG field length of an SRv6 SID - srv6-sid-func-value: Typedef for FUNCT value of an SRv6 SID - srv6-sid-func-value-reserved-type: Enum (list) of "reserved" FUNCT opcode - srv6-endpoint-type: SRv6 Endpoint behaviors [RFC8986] identity type Raza, et al. Expires 8 January 2026 [Page 8] Internet-Draft YANG Data Model for SRv6 July 2025 - srv6-sid-structure: Grouping that defines structure of an SRv6 SID in terms of LBL (Locator Block Length), LNL (Locator Node Length), FL (Function Length), and AL (Argument Length). Please refer Section 3.1. - srv6-sid-compression-type: Enum that lists compression types for an SRv6 SID as uncompressed, compressed-next, and compressed-replace. Please refer Section 3.2. - srv6-sid-format-types: Identifies well known SID formats from each compression type. Please refer Section 3.3 * Other: - srv6-headend-type: SRv6 Headend behaviors [RFC8986] identity type - srv6-security-type: SRv6 Security rules identity type - srv6-counter-type: SRv6 Counters [RFC8986] identity type The corresponding YANG specification for this module is captured in Section 6.1. 4.3. SRv6 Base The base SRv6 model is specified in ietf-srv6-base module. This module augments "/rt:routing:/sr:segment-routing" [RFC9020] and specifies the configuration, operational state, and notification events that are required to manage the base SRv6. The corresponding YANG specification for this module is captured in Section 6.2. 4.3.1. Configuration The module defines some fundamental items required to configure an SRv6 network: * SRv6 Enablement: Enable Segment-Routing SRv6 feature * Encapsulation Parameters: Provide encapsulation related parameters (such as source-address, hop-limit, and traffic-class) to be used when performing H.Encaps* operation. Raza, et al. Expires 8 January 2026 [Page 9] Internet-Draft YANG Data Model for SRv6 July 2025 * SID Formats: Configures SID format specific parameters - e.g. provide configuration option to change GIB/LIB split for NEXT-CSID formats. The Section 3.4 describes SID format's specific parameters in more details. * Locator(s) Specification: SRv6 locator is a fundamental construct for an SRv6 network. This is the base manageability construct for SID allocation (see Section 3.4) on the local box, and also advertised as IPV6 prefix for node reachability. The key attributes of a locator are: - Name: This is an identifier for a locator. - SID format: The SID format associated with the locator that dictates both the locator prefix and the SIDs allocated from the locator. - Prefix: Specifies locator's IPv6 prefix for node reachability and SID allocation, either off the locator (for uncompressed SIDs) or off the locator block (for CSIDs). - Algorithm: A locator can be associated to an IGP algorithm for FlexAlgo use. By default, locator's algorithm is default algorithm (0). - Anycast: Specifies locator as an anycast locator, allowing anycast operations in IGP - Auto-allocation of Node SID: As locator becomes operational, a Node SID can be automatically allocated with default variant (e.g. End_PSP_USD). This configuration allows either to disable the auto-allocation, or to change the default variant. * SIDs: SRv6 SIDs related configuration parameters: - sid-holdtime: The holdtime before releasing a previously allocated SID to free pool Following is a simplified graphical tree representation of the data model for SRv6 base configuration Raza, et al. Expires 8 January 2026 [Page 10] Internet-Draft YANG Data Model for SRv6 July 2025 module: ietf-srv6-base augment /rt:routing/sr:segment-routing: +--rw srv6 +--rw enable? boolean +--rw encapsulation | +--rw source-address? inet:ipv6-address | +--rw hop-limit | | +--rw value? uint8 | | +--rw propagate? boolean | +--rw traffic-class | +--rw value? uint8 | +--rw propagate? boolean +--rw sid-formats | +--rw format* [type] | +--rw type identityref | +--rw uncompressed-16 | | +--rw id-block | | +--rw explicit | | +--rw start? uint16 | | +--rw size? uint16 | +--rw csid-next-16 | | +--rw local-id-block | | +--rw start? uint16 | | +--rw explicit | | +--rw start? uint16 | | +--rw size? uint16 | +--rw csid-replace +--rw locators | +--rw locator* [name] | | +--rw name srv6-types:srv6-locator-name-type | | +--rw enable? boolean | | +--rw format identityref | | +--rw prefix | | | +--rw address inet:ipv6-address | | | +--rw length srv6-types:srv6-locator-len | | +--rw algorithm? uint8 | | +--rw anycast? boolean | | +--rw node-sid-auto-allocation | | +--rw behavior? identityref | | +--rw disable? boolean +--rw sids +--rw sid-holdtime? uint8 Figure 3: SRv6 Base - Config Tree Raza, et al. Expires 8 January 2026 [Page 11] Internet-Draft YANG Data Model for SRv6 July 2025 4.3.2. State As per NMDA model, the state related to configuration items specified in above section Section 4.3.1 can be retrieved from the same tree. This section defines other operational state items related to SRv6 base. The operational state corresponding to the SRv6 base includes: * Node capabilities: provides information on the node (hardware) capabilities and support regarding various SRv6 aspects and features including endpoint behaviors, headend behaviors, security rules, counter/stats support, and other SRv6 parameters that need to be signaled in an SRv6 network by the protocols. * SID Formats: provides information related to supported SID formats. The information includes format's description, compression type, and SID structure. * Locators: provides information related to local and remote locators. The local locators information includes locator operational state, and state of address conflict with any ipv6 address configured on local interfaces etc. The remote locators information includes traffic accounting for a remote locator prefix. * sid: provides information related to locally allocated and instantiated SIDs on the node. This includes two types of information: 1. aggregate across all SIDs such as aggregate counts and summary 2. per SID information such as SID value, behavior, associated locator, allocation type (dynamic or explicit), SID owner protocol(s)/client(s), forwarding [paths] information, and stats/counters. Following is a simplified graphical tree representation of the data model for the SRv6 operational state (for read-only items): module: ietf-srv6-base augment /rt:routing/sr:segment-routing: +--rw srv6 +--ro node-capabilities | +--ro end-behavior* [type] | | +--ro type identityref | | +--ro supported boolean Raza, et al. Expires 8 January 2026 [Page 12] Internet-Draft YANG Data Model for SRv6 July 2025 | +--ro headend-behavior* [type] | | +--ro type identityref | | +--ro supported boolean | +--ro msd | | +--ro max-sl? uint8 | | +--ro max-end-pop? uint8 | | +--ro max-h_encap? uint8 | | +--ro max-end_d? uint8 | +--ro security-rule* [type] | | +--ro type identityref | | +--ro supported boolean | +--ro counters* [type] | +--ro type identityref | +--ro supported boolean +--rw sid-formats | +--rw format* [type] | +--rw type identityref | +--ro compression-type? srv6-types:srv6-sid-compression-type | +--ro description? string | +--ro sid-structure | +--ro locator-block-length? srv6-types:srv6-locator-block-len | +--ro locator-node-length? srv6-types:srv6-locator-node-len | +--ro function-length? srv6-types:srv6-sid-func-len | +--ro argument-length? srv6-types:srv6-sid-arg-len +--rw locators | +--rw locator* [name] | | +--rw name srv6-types:srv6-locator-name-type | | +--ro operational-status? srv6-types:srv6-status-type | | +--ro is-in-address-conflict? boolean | +--ro remote* [prefix] | +--ro prefix inet:ipv6-prefix | +--ro traffic-accounting | +--ro inbound | | +--ro in-pkts? yang:counter64 | | +--ro in-octets? yang:counter64 | +--ro outbound | +--ro paths* [interface next-hop] | +--ro interface if:interface-ref | +--ro next-hop inet:ipv6-address | +--ro out-pkts? yang:counter64 | +--ro out-octets? yang:counter64 +--rw sids +--ro counts | +--ro allocated? uint32 | +--ro stale? uint32 +--ro sid* [sid] +--ro sid srv6-types:srv6-sid +--ro behavior? identityref Raza, et al. Expires 8 January 2026 [Page 13] Internet-Draft YANG Data Model for SRv6 July 2025 +--ro locator? -> /rt:routing/sr:segment-routing/srv6:srv6/locators/locator/name +--ro allocation | +--ro alloc-type? srv6-types:sid-alloc-type | +--ro owner* [type instance] | | +--ro type identityref | | +--ro instance string | | +--ro is-winner? boolean | +--ro allocated-from-reserved? boolean +--ro forwarding | +--ro is-installed? boolean | +--ro next-hop-type? srv6-types:srv6-nexthop-type | +--ro paths | +--ro path* [path-index] | +--ro path-index uint8 | +--ro l2 | | +--ro interface? if:interface-ref | | +--ro lookup-table-id? uint32 | +--ro l3 | | +--ro interface? if:interface-ref | | +--ro next-hop? inet:ip-address | | +--ro weight? uint32 | | +--ro role? enumeration | | +--ro backup-path-index? uint8 | | +--ro lookup-table-id? uint32 | +--ro (encap-type)? | +--:(srv6) | | +--ro out-sid* [sid] | | +--ro sid srv6-types:srv6-sid | +--:(mpls) | +--ro out-label* [label] | +--ro label rt-types:mpls-label +--ro counters +--ro success +--ro in-pkts? yang:counter64 +--ro in-octets? yang:counter64 Figure 4: SRv6 Base - State Tree 4.3.3. Notification This model defines a list of notifications to inform an operator of important events detected during the SRv6 operation. These events include events related to: * locator operational state changes * SID (allocation) collision event Raza, et al. Expires 8 January 2026 [Page 14] Internet-Draft YANG Data Model for SRv6 July 2025 Following is a simplified graphical tree representation of the data model for SRv6 notifications: module: ietf-srv6-base notifications: +---n srv6-locator-status-event | +--ro operational-status? srv6-types:srv6-status-type | +--ro locator? -> /rt:routing/sr:segment-routing/srv6:srv6/locators/locator/name +---n srv6-sid-collision-event +--ro sid? srv6-types:srv6-sid +--ro existing | +--ro end-behavior-type? identityref | +--ro owner* [type instance] | +--ro type identityref | +--ro instance string +--ro requested +--ro end-behavior-type? identityref +--ro requester +--ro type? identityref +--ro instance? string Figure 5: SRv6 Base - Notification Tree 4.4. SRv6 Static SRv6-Static application allows a user to specify SRv6 local SIDs and program them in the forwarding plane. The SRv6-Static model is captured in the ietf-srv6-static module. The associated YANG specification for this module is captured in Section 6.3. 4.4.1. Configuration The SRv6-Static configuration augments the SRv6-base locator tree "/rt:routing/sr:segment-routing/srv6:srv6/srv6:locators/srv6:locator" Following are salient features of the SRv6-Static config model: * Allows static (explicit) configuration for local-SIDs under a given locator. * Given that entry is scoped under a locator, the key for each entry is "function" value. Raza, et al. Expires 8 January 2026 [Page 15] Internet-Draft YANG Data Model for SRv6 July 2025 * A user must also specify end-behavior type (End*) associated with the entry. * A user must also specify behavior-specific data with each entry. For example, for any end behavior requiring a table lookup, a lookup-table need be provided. Similarly, for any end behavior with forwarding next-hops need to specify next-hop information. The example of former include End, End.T, End.DT4, End.DT6, and End.DT46, whereas example of later include End.X, End.DX4, End.DX6, End.B6, End.BM etc. * Each local-SID entry has zero or more forwarding paths specified. * A forwarding path has next-hop type that depends on the end behavior, and could be either ipv6, or ipv4, or mpls, or l2 type. For example, End.X, End.DX4, End.DX6, End.B6, End.BM, and End.DX2 will have ipv6, ipv4, ipv6, ipv6, mpls, and l2 next-hop types respectively * For each forwarding next-hop type, the appropriate path attributes are to be specified as well. For L2 type, the only other information required is the L2 interface name. Whereas for L3 (ipv6, ipv4, mpls) types, the information includes L3 interface name, next-hop IP address, weight, and protection information. * Depending on the end behavior type, a forwarding path may have either MPLS or SRv6 encapsulation -- i.e., Stack of out-labels or Stack of SRv6 out-SIDs. The example of former is End.BM and example of later include the rest (End.X, End.DX4, End.DX6, End.B6 etc.). Following is a simplified graphical tree representation of the data model for SRv6 Static configuration module: ietf-srv6-static augment /rt:routing/sr:segment-routing/srv6:srv6/srv6:locators/srv6:locator: +--rw static +--rw sids +--rw sid* [function] +--rw function srv6-types:srv6-sid-func-value +--rw end-behavior-type identityref +--rw end +--rw end_psp +--rw end_usp +--rw end_psp_usp +--rw end_usd +--rw end_psp_usd +--rw end_usp_usd Raza, et al. Expires 8 January 2026 [Page 16] Internet-Draft YANG Data Model for SRv6 July 2025 +--rw end_psp_usp_usd +--rw end-t | +--rw lookup-table-ipv6 srv6-types:table-id +--rw end-t_psp | +--rw lookup-table-ipv6 srv6-types:table-id +--rw end-t_usp | +--rw lookup-table-ipv6 srv6-types:table-id +--rw end-t_psp_usp | +--rw lookup-table-ipv6 srv6-types:table-id +--rw end-t_usd | +--rw lookup-table-ipv6 srv6-types:table-id +--rw end-t_psp_usd | +--rw lookup-table-ipv6 srv6-types:table-id +--rw end-t_usp_usd | +--rw lookup-table-ipv6 srv6-types:table-id +--rw end-t_psp_usp_usd | +--rw lookup-table-ipv6 srv6-types:table-id +--rw end-x | +--rw protected? boolean | +--rw paths | +--rw path* [path-index] | +--rw path-index uint8 | +--rw interface? if:interface-ref | +--rw next-hop? inet:ipv6-address | +--rw table? srv6-types:table-id | +--rw weight? uint32 | +--rw role? enumeration | +--rw backup-path-index? uint8 | +--rw sid-list | +--rw out-sid* [sid] | +--rw sid srv6-types:srv6-sid +--rw end-x_psp | +--rw protected? boolean | +--rw paths | +--rw path* [path-index] | +--rw path-index uint8 | +--rw interface? if:interface-ref | +--rw next-hop? inet:ipv6-address | +--rw table? srv6-types:table-id | +--rw weight? uint32 | +--rw role? enumeration | +--rw backup-path-index? uint8 | +--rw sid-list | +--rw out-sid* [sid] | +--rw sid srv6-types:srv6-sid +--rw end-x_usp | +--rw protected? boolean | +--rw paths Raza, et al. Expires 8 January 2026 [Page 17] Internet-Draft YANG Data Model for SRv6 July 2025 | +--rw path* [path-index] | +--rw path-index uint8 | +--rw interface? if:interface-ref | +--rw next-hop? inet:ipv6-address | +--rw table? srv6-types:table-id | +--rw weight? uint32 | +--rw role? enumeration | +--rw backup-path-index? uint8 | +--rw sid-list | +--rw out-sid* [sid] | +--rw sid srv6-types:srv6-sid +--rw end-x_psp_usp | +--rw protected? boolean | +--rw paths | +--rw path* [path-index] | +--rw path-index uint8 | +--rw interface? if:interface-ref | +--rw next-hop? inet:ipv6-address | +--rw table? srv6-types:table-id | +--rw weight? uint32 | +--rw role? enumeration | +--rw backup-path-index? uint8 | +--rw sid-list | +--rw out-sid* [sid] | +--rw sid srv6-types:srv6-sid +--rw end-x_usd | +--rw protected? boolean | +--rw paths | +--rw path* [path-index] | +--rw path-index uint8 | +--rw interface? if:interface-ref | +--rw next-hop? inet:ipv6-address | +--rw table? srv6-types:table-id | +--rw weight? uint32 | +--rw role? enumeration | +--rw backup-path-index? uint8 | +--rw sid-list | +--rw out-sid* [sid] | +--rw sid srv6-types:srv6-sid +--rw end-x_psp_usd | +--rw protected? boolean | +--rw paths | +--rw path* [path-index] | +--rw path-index uint8 | +--rw interface? if:interface-ref | +--rw next-hop? inet:ipv6-address | +--rw table? srv6-types:table-id | +--rw weight? uint32 Raza, et al. Expires 8 January 2026 [Page 18] Internet-Draft YANG Data Model for SRv6 July 2025 | +--rw role? enumeration | +--rw backup-path-index? uint8 | +--rw sid-list | +--rw out-sid* [sid] | +--rw sid srv6-types:srv6-sid +--rw end-x_usp_usd | +--rw protected? boolean | +--rw paths | +--rw path* [path-index] | +--rw path-index uint8 | +--rw interface? if:interface-ref | +--rw next-hop? inet:ipv6-address | +--rw table? srv6-types:table-id | +--rw weight? uint32 | +--rw role? enumeration | +--rw backup-path-index? uint8 | +--rw sid-list | +--rw out-sid* [sid] | +--rw sid srv6-types:srv6-sid +--rw end-x_psp_usp_usd | +--rw protected? boolean | +--rw paths | +--rw path* [path-index] | +--rw path-index uint8 | +--rw interface? if:interface-ref | +--rw next-hop? inet:ipv6-address | +--rw table? srv6-types:table-id | +--rw weight? uint32 | +--rw role? enumeration | +--rw backup-path-index? uint8 | +--rw sid-list | +--rw out-sid* [sid] | +--rw sid srv6-types:srv6-sid +--rw end-b6-encaps | +--rw policy-name string | +--rw source-address inet:ipv6-address | +--rw paths | +--rw path* [path-index] | +--rw path-index uint8 | +--rw interface? if:interface-ref | +--rw next-hop? inet:ipv6-address | +--rw table? srv6-types:table-id | +--rw weight? uint32 | +--rw role? enumeration | +--rw backup-path-index? uint8 | +--rw sid-list | +--rw out-sid* [sid] | +--rw sid srv6-types:srv6-sid Raza, et al. Expires 8 January 2026 [Page 19] Internet-Draft YANG Data Model for SRv6 July 2025 +--rw end-bm | +--rw policy-name string | +--rw paths | +--rw path* [path-index] | +--rw path-index uint8 | +--rw interface? if:interface-ref | +--rw next-hop? inet:ip-address | +--rw weight? uint32 | +--rw role? enumeration | +--rw backup-path-index? uint8 | +--rw sid-list | +--rw out-sid* [sid] | +--rw sid srv6-types:srv6-sid +--rw end-dx6 | +--rw paths | +--rw path* [path-index] | +--rw path-index uint8 | +--rw interface? if:interface-ref | +--rw next-hop? inet:ipv6-address | +--rw table? srv6-types:table-id | +--rw weight? uint32 | +--rw role? enumeration | +--rw backup-path-index? uint8 | +--rw sid-list | +--rw out-sid* [sid] | +--rw sid srv6-types:srv6-sid +--rw end-dx4 | +--rw paths | +--rw path* [path-index] | +--rw path-index uint8 | +--rw interface? if:interface-ref | +--rw next-hop? inet:ipv4-address | +--rw table? srv6-types:table-id | +--rw weight? uint32 | +--rw role? enumeration | +--rw backup-path-index? uint8 | +--rw sid-list | +--rw out-sid* [sid] | +--rw sid srv6-types:srv6-sid +--rw end-dt6 | +--rw lookup-table-ipv6 srv6-types:table-id +--rw end-dt4 | +--rw lookup-table-ipv4 srv6-types:table-id +--rw end-dt46 | +--rw lookup-table-ipv4 srv6-types:table-id | +--rw lookup-table-ipv6 srv6-types:table-id +--rw end-dx2 | +--rw path Raza, et al. Expires 8 January 2026 [Page 20] Internet-Draft YANG Data Model for SRv6 July 2025 | +--rw l2-interface if:interface-ref +--rw end-dx2v | +--rw lookup-table-vlan srv6-types:table-id +--rw end-dt2u | +--rw lookup-table-mac srv6-types:table-id +--rw end-dt2m +--rw flooding-table srv6-types:table-id +--rw paths +--rw path* [path-index] +--rw path-index uint8 +--rw l2-interface? if:interface-ref Figure 6: SRv6 Static - Config Tree 4.4.2. State As per NMDA model, the state related to configuration items specified in above section Section 4.4.1 can be retrieved from the same tree. The state regarding the local-SIDs created by SRv6-static model can be obtained using the state model of SRv6-base. Hence, there is no additional state identified at this time for SRv6-static. 4.4.3. Notification None. 5. Pending Items Following are the items that will be addressed in next revisions: * Extend local-SID collision event/notification in SRv6-base model. * Add RPC support in the SRv6-base model. * Add ARGS support in the SRv6-Static model. * QoS support 6. YANG Specification Following are actual YANG definition for SRv6 modules defined earlier in the document. 6.1. SRv6 Types This YANG module imports types defined in [RFC6991]. Raza, et al. Expires 8 January 2026 [Page 21] Internet-Draft YANG Data Model for SRv6 July 2025 Moreover, the module models behaviors defined in [RFC8986], [I-D.ietf-spring-sr-service-programming], and [RFC9433]. file "ietf-srv6-types@2025-07-07.yang" // RFC Editor: replace the above date with the date of // publication and remove this note. module ietf-srv6-types { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-srv6-types"; prefix srv6-types; import ietf-inet-types { prefix inet; reference "RFC 6991: Common YANG Data Types"; } organization "IETF SPRING Working Group"; contact "WG Web: WG List: Editor: Kamran Raza Editor: Jaganbabu Rajamanickam Editor: Xufeng Liu Editor: Zhibo Hu Editor: Iftekhar Hussain Editor: Himanshu Shah Editor: Daniel Voyer Editor: Hani Elmalky Raza, et al. Expires 8 January 2026 [Page 22] Internet-Draft YANG Data Model for SRv6 July 2025 Editor: Satoru Matsushima Editor: Katsuhiro Horiba Editor: Ahmed AbdelSalam Editor: Pingping Yu "; description "This YANG module defines the essential types for the management of Segment-Routing with IPv6 dataplane (SRv6). Copyright (c) 2018 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 Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (http://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 2025-07-07 { description "Adding compressed SID and few other missing def"; reference "RFC XXXX: YANG Data Model for SRv6"; // RFC Editor: replace XXXX with actual RFC number and remove // this note } revision 2024-11-21 { description "Added SID structure definition and "; reference "RFC XXXX: YANG Data Model for SRv6"; Raza, et al. Expires 8 January 2026 [Page 23] Internet-Draft YANG Data Model for SRv6 July 2025 // RFC Editor: replace XXXX with actual RFC number and remove // this note } revision 2024-03-04 { description "Renamed some of End identities"; reference "RFC XXXX: YANG Data Model for SRv6"; // RFC Editor: replace XXXX with actual RFC number and remove // this note } revision 2022-01-14 { description "Alignment with SRv6 net-pgm rev16"; reference "RFC XXXX: YANG Data Model for SRv6"; // RFC Editor: replace XXXX with actual RFC number and remove // this note } revision 2019-10-30 { description "Renaming of some types"; reference "RFC XXXX: YANG Data Model for SRv6"; // RFC Editor: replace XXXX with actual RFC number and remove // this note } revision 2019-07-08 { description "Alignment with latest SRv6 network programming"; reference "RFC XXXX: YANG Data Model for SRv6"; // RFC Editor: replace XXXX with actual RFC number and remove // this note } revision 2018-10-22 { description "Initial revision."; reference "RFC XXXX: YANG Data Model for SRv6"; // RFC Editor: replace XXXX with actual RFC number and remove // this note } Raza, et al. Expires 8 January 2026 [Page 24] Internet-Draft YANG Data Model for SRv6 July 2025 identity srv6-endpoint-type { description "Base identity from which specific SRv6 Endpoint types are derived."; } /* Endpoints defined under draft-ietf-spring- * srv6-network-programming */ identity End { base srv6-endpoint-type; description "End function (variant: no PSP, no USP)."; reference "RFC 8986"; } identity End_PSP { base srv6-endpoint-type; description "End function (variant: PSP only)."; reference "RFC 8986"; } identity End_USP { base srv6-endpoint-type; description "End function (variant: USP only)."; reference "RFC 8986"; } identity End_PSP_USP { base srv6-endpoint-type; description "End function (variant: PSP and USP)."; reference "RFC 8986"; } identity End.X { base srv6-endpoint-type; description "Endpoint with cross-connect to an array of layer-3 adjacencies (variant: no PSP, no USP)."; reference "RFC 8986"; } Raza, et al. Expires 8 January 2026 [Page 25] Internet-Draft YANG Data Model for SRv6 July 2025 identity End.X_PSP { base srv6-endpoint-type; description "Endpoint with cross-connect to an array of layer-3 adjacencies (variant: PSP only)."; reference "RFC 8986"; } identity End.X_USP { base srv6-endpoint-type; description "Endpoint with cross-connect to an array of layer-3 adjacencies (variant: USP only)."; reference "RFC 8986"; } identity End.X_PSP_USP { base srv6-endpoint-type; description "Endpoint with cross-connect to an array of layer-3 adjacencies (variant: PSP and USP)."; reference "RFC 8986"; } identity End.T { base srv6-endpoint-type; description "Endpoint with specific IPv6 table lookup (variant: no PSP, no USP)."; reference "RFC 8986"; } identity End.T_PSP { base srv6-endpoint-type; description "Endpoint with specific IPv6 table lookup (variant: PSP only)."; reference "RFC 8986"; } identity End.T_USP { base srv6-endpoint-type; description Raza, et al. Expires 8 January 2026 [Page 26] Internet-Draft YANG Data Model for SRv6 July 2025 "Endpoint with specific IPv6 table lookup (variant: USP only)."; reference "RFC 8986"; } identity End.T_PSP_USP { base srv6-endpoint-type; description "Endpoint with specific IPv6 table lookup (variant: PSP and USP)."; reference "RFC 8986"; } // TODO: End.B6.Insert identity End.B6.Encaps { base srv6-endpoint-type; description "Endpoint bound to an SRv6 Policy where the SRv6 Policy also includes an IPv6 Source Address A."; reference "RFC 8986"; } identity End.BM { base srv6-endpoint-type; description "Endpoint bound to an SR-MPLS Policy"; reference "RFC 8986"; } identity End.DX6 { base srv6-endpoint-type; description "Endpoint with decapsulation and cross-connect to an array of IPv6 adjacencies"; reference "RFC 8986"; } identity End.DX4 { base srv6-endpoint-type; description "Endpoint with decapsulation and cross-connect to an array of IPv4 adjacencies"; Raza, et al. Expires 8 January 2026 [Page 27] Internet-Draft YANG Data Model for SRv6 July 2025 reference "RFC 8986"; } identity End.DT6 { base srv6-endpoint-type; description "Endpoint with decapsulation and specific IPv6 table lookup"; reference "RFC 8986"; } identity End.DT4 { base srv6-endpoint-type; description "Endpoint with decapsulation and specific IPv4 table lookup"; reference "RFC 8986"; } identity End.DT46 { base srv6-endpoint-type; description "Endpoint with decapsulation and specific IP (IPv4 or IPv6) table lookup"; reference "RFC 8986"; } identity End.DX2 { base srv6-endpoint-type; description "Endpoint with decapsulation and Layer-2 cross-connect to an L2 interface"; reference "RFC 8986"; } identity End.DX2V { base srv6-endpoint-type; description "Endpoint with decapsulation and specific VLAN L2 table lookup"; reference "RFC 8986"; } Raza, et al. Expires 8 January 2026 [Page 28] Internet-Draft YANG Data Model for SRv6 July 2025 identity End.DT2U { base srv6-endpoint-type; description "Endpoint with decapsulation and specific unicast MAC L2 table lookup"; reference "RFC 8986"; } identity End.DT2M { base srv6-endpoint-type; description "Endpoint with decapsulation and specific L2 table flooding"; reference "RFC 8986"; } // TODO: End.B6.Insert.Red identity End.B6.Encaps.Red { base srv6-endpoint-type; description "This is a reduced encap variation of the End.B6.Encap behavior."; reference "RFC 8986"; } identity End_USD { base srv6-endpoint-type; description "End function (variant: USD)."; reference "RFC 8986"; } identity End_PSP_USD { base srv6-endpoint-type; description "End function (variant: PSP and USD)."; reference "RFC 8986"; } identity End_USP_USD { base srv6-endpoint-type; description "End function (variant: USP and USD)."; Raza, et al. Expires 8 January 2026 [Page 29] Internet-Draft YANG Data Model for SRv6 July 2025 reference "RFC 8986"; } identity End_PSP_USP_USD { base srv6-endpoint-type; description "End function (variant: PSP and USP and USD)."; reference "RFC 8986"; } identity End.X_USD { base srv6-endpoint-type; description "Endpoint with cross-connect to an array of layer-3 adjacencies (variant: USD)."; reference "RFC 8986"; } identity End.X_PSP_USD { base srv6-endpoint-type; description "Endpoint with cross-connect to an array of layer-3 adjacencies (variant: PSP and USD)."; reference "RFC 8986"; } identity End.X_USP_USD { base srv6-endpoint-type; description "Endpoint with cross-connect to an array of layer-3 adjacencies (variant: USP and USD)."; reference "RFC 8986"; } identity End.X_PSP_USP_USD { base srv6-endpoint-type; description "Endpoint with cross-connect to an array of layer-3 adjacencies (variant: PSP and USP and USD)."; reference "RFC 8986"; } Raza, et al. Expires 8 January 2026 [Page 30] Internet-Draft YANG Data Model for SRv6 July 2025 identity End.T_USD { base srv6-endpoint-type; description "Endpoint with decapsulation and Layer-2 cross-connect to an L2 interface"; reference "RFC 8986"; } identity End.T_PSP_USD { base srv6-endpoint-type; description "Endpoint with specific IPv6 table lookup (variant: PSP and USD)."; reference "RFC 8986"; } identity End.T_USP_USD { base srv6-endpoint-type; description "Endpoint with specific IPv6 table lookup (variant: USP and USD)."; reference "RFC 8986"; } identity End.T_PSP_USP_USD { base srv6-endpoint-type; description "Endpoint with specific IPv6 table lookup (variant: PSP and USP and USD)."; reference "RFC 8986"; } identity End.MAP { base srv6-endpoint-type; description "DMM End.MAP"; reference "RFC9433"; } identity End.Limit { base srv6-endpoint-type; description "DMM End.Limit"; reference Raza, et al. Expires 8 January 2026 [Page 31] Internet-Draft YANG Data Model for SRv6 July 2025 "RFC9433"; } /* Endpoints defined under RFC9800 */ identity END.NEXT-ONLY-CSID { base srv6-endpoint-type; description "End SID with the NEXT-ONLY-CSID flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.NEXT-CSID { base srv6-endpoint-type; description "End SID with the NEXT-CSID flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.NEXT-CSID_PSP { base srv6-endpoint-type; description "End SID with the NEXT-CSID PSP flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.NEXT-CSID_USP { base srv6-endpoint-type; description "End SID with the NEXT-CSID USP flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.NEXT-CSID_PSP_USP { base srv6-endpoint-type; description Raza, et al. Expires 8 January 2026 [Page 32] Internet-Draft YANG Data Model for SRv6 July 2025 "End SID with the NEXT-CSID PSP/USP flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.NEXT-CSID_USD { base srv6-endpoint-type; description "End SID with the NEXT-CSID USD flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.NEXT-CSID_PSP_USD { base srv6-endpoint-type; description "End SID with the NEXT-CSID PSP/USD flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.NEXT-CSID_USP_USD { base srv6-endpoint-type; description "End SID with the NEXT-CSID USP/USD flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.NEXT-CSID_PSP_USP_USD { base srv6-endpoint-type; description "End SID with the NEXT-CSID PSP/USP/USD flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.NEXT-CSID_ONLY { Raza, et al. Expires 8 January 2026 [Page 33] Internet-Draft YANG Data Model for SRv6 July 2025 base srv6-endpoint-type; description "End.X SID with the NEXT-ONLY-CSID flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.X.NEXT-CSID { base srv6-endpoint-type; description "End.X SID with the NEXT-CSID flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.X.NEXT-CSID_PSP { base srv6-endpoint-type; description "End.X SID with the NEXT-CSID PSP flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.X.NEXT-CSID_USP { base srv6-endpoint-type; description "End.X SID with the NEXT-CSID USP flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.X.NEXT-CSID_PSP_USP { base srv6-endpoint-type; description "End.X SID with the NEXT-CSID PSP/USP flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } Raza, et al. Expires 8 January 2026 [Page 34] Internet-Draft YANG Data Model for SRv6 July 2025 identity END.X.NEXT-CSID_USD { base srv6-endpoint-type; description "End.X SID with the NEXT-CSID USD flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.X.NEXT-CSID_PSP_USD { base srv6-endpoint-type; description "End.X SID with the NEXT-CSID PSP/USD flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.X.NEXT-CSID_USP_USD { base srv6-endpoint-type; description "End.X SID with the NEXT-CSID USP/USD flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.X.NEXT-CSID_PSP_USP_USD { base srv6-endpoint-type; description "End.X SID with the NEXT-CSID PSP/USP/USD flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity End.DX6.NEXT-CSID { base srv6-endpoint-type; description "NEXT-CSID Endpoint with decapsulation and cross-connect to an array of IPv6 adjacencies"; reference "RFC 9800"; } Raza, et al. Expires 8 January 2026 [Page 35] Internet-Draft YANG Data Model for SRv6 July 2025 identity End.DX4.NEXT-CSID { base srv6-endpoint-type; description "NEXT-CSID Endpoint with decapsulation and cross-connect to an array of IPv4 adjacencies"; reference "RFC 9800"; } identity End.DT6.NEXT-CSID { base srv6-endpoint-type; description "NEXT-CSID Endpoint with decapsulation and specific IPv6 table lookup"; reference "RFC 9800"; } identity End.DT4.NEXT-CSID { base srv6-endpoint-type; description "NEXT-CSID Endpoint with decapsulation and specific IPv4 table lookup"; reference "RFC 9800"; } identity End.DT46.NEXT-CSID { base srv6-endpoint-type; description "NEXT-CSID Endpoint with decapsulation and specific IP (IPv4 or IPv6) table lookup"; reference "RFC 9800"; } identity End.DX2.NEXT-CSID { base srv6-endpoint-type; description "NEXT-CSID Endpoint with decapsulation and Layer-2 cross-connect to an L2 interface"; reference "RFC 9800"; } identity End.DX2V.NEXT-CSID { base srv6-endpoint-type; description Raza, et al. Expires 8 January 2026 [Page 36] Internet-Draft YANG Data Model for SRv6 July 2025 "NEXT-CSID Endpoint with decapsulation and specific VLAN L2 table lookup"; reference "RFC 9800"; } identity End.DT2U.NEXT-CSID { base srv6-endpoint-type; description "NEXT-CSID Endpoint with decapsulation and specific unicast MAC L2 table lookup"; reference "RFC 9800"; } identity End.DT2M.NEXT-CSID { base srv6-endpoint-type; description "NEXT-CSID Endpoint with decapsulation and specific L2 table flooding"; reference "RFC 9800"; } /* DMM - RFC9433 */ identity End.M.GTP6.D { base srv6-endpoint-type; description "DMM End.M.GTP6.D"; reference "RFC 9433"; } identity End.M.GTP6.Di { base srv6-endpoint-type; description "DMM End.M.GTP6.Di"; reference "RFC 9433"; } identity End.M.GTP6.E { base srv6-endpoint-type; description "DMM End.M.GTP6.E"; reference "RFC 9433"; Raza, et al. Expires 8 January 2026 [Page 37] Internet-Draft YANG Data Model for SRv6 July 2025 } identity End.M.GTP4.E { base srv6-endpoint-type; description "DMM End.M.GTP4.E"; reference "RFC 9433"; } /* DMM end */ // TODO: END.DTM // TODO: End.M // TODO: End.Replicate // TODO: End.DTMC4 // TODO: End.DTMC6 // TODO: End.DTMC46 // TODO: End.T NEXT-CSID ... identity END.B6.Encaps.NEXT-CSID { base srv6-endpoint-type; description "End.B6.Encaps SID with the NEXT-CSID flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.B6.Encaps.Red.NEXT-CSID { base srv6-endpoint-type; description "End.B6.Encaps.Red SID with the NEXT-CSID flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.BM.NEXT-CSID { base srv6-endpoint-type; description "End.BM SID with the NEXT-CSID flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note Raza, et al. Expires 8 January 2026 [Page 38] Internet-Draft YANG Data Model for SRv6 July 2025 } identity END.REPLACE-SID { base srv6-endpoint-type; description "End SID with the REPLACE-CSID flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.REPLACE-SID_PSP { base srv6-endpoint-type; description "End SID with the REPLACE-CSID PSP flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.REPLACE-SID_USP { base srv6-endpoint-type; description "End SID with the REPLACE-CSID USP flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.REPLACE-SID_PSP_USP { base srv6-endpoint-type; description "End SID with the REPLACE-CSID PSP/USP flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.X.REPLACE-CSID { base srv6-endpoint-type; description "End.X SID with the REPLACE-CSID flavor"; reference "RFC 9800"; Raza, et al. Expires 8 January 2026 [Page 39] Internet-Draft YANG Data Model for SRv6 July 2025 // RFC Editor: replace with actual RFC number and remove this // note } identity END.X.REPLACE-CSID_PSP { base srv6-endpoint-type; description "End.X SID with the REPLACE-CSID PSP flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.X.REPLACE-CSID_USP { base srv6-endpoint-type; description "End.X SID with the REPLACE-CSID USP flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.X.REPLACE-CSID_PSP_USP { base srv6-endpoint-type; description "End SID with the REPLACE-CSID PSP/USP flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } // TODO: End.T REPLACE-CSID identity END.B6.Encaps.REPLACE-CSID { base srv6-endpoint-type; description "End.B6.Encaps SID with the REPLACE-CSID flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.BM.REPLACE-CSID { base srv6-endpoint-type; Raza, et al. Expires 8 January 2026 [Page 40] Internet-Draft YANG Data Model for SRv6 July 2025 description "End.BM.Red SID with the REPLACE-CSID flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.DX6.REPLACE-CSID { base srv6-endpoint-type; description "End.DX6 SID with the REPLACE-CSID flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.DX4.REPLACE-CSID { base srv6-endpoint-type; description "End.DX4 SID with the REPLACE-CSID flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.DT6.REPLACE-CSID { base srv6-endpoint-type; description "End.DT6 SID with the REPLACE-CSID flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.DT4.REPLACE-CSID { base srv6-endpoint-type; description "End.DT4 SID with the REPLACE-CSID flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } Raza, et al. Expires 8 January 2026 [Page 41] Internet-Draft YANG Data Model for SRv6 July 2025 identity END.DT46.REPLACE-CSID { base srv6-endpoint-type; description "End.DT46 SID with the REPLACE-CSID flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.DX2.REPLACE-CSID { base srv6-endpoint-type; description "End.DX2 SID with the REPLACE-CSID flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.DX2V.REPLACE-CSID { base srv6-endpoint-type; description "End.DX2V SID with the REPLACE-CSID flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.DT2U.REPLACE-CSID { base srv6-endpoint-type; description "End.DT2U SID with the REPLACE-CSID flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.DT2M.REPLACE-CSID { base srv6-endpoint-type; description "End.DT2M SID with the REPLACE-CSID flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note Raza, et al. Expires 8 January 2026 [Page 42] Internet-Draft YANG Data Model for SRv6 July 2025 } identity END.B6.Encaps.Red.REPLACE-CSID { base srv6-endpoint-type; description "End.B6.Encaps.Red SID with the REPLACE-CSID flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.REPLACE-SID_USD { base srv6-endpoint-type; description "End SID with the REPLACE-CSID USD flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.REPLACE-SID_PSP_USD { base srv6-endpoint-type; description "End SID with the REPLACE-CSID PSP/USD flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.REPLACE-SID_USP_USD { base srv6-endpoint-type; description "End SID with the REPLACE-CSID USP/USD flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.REPLACE-SID_PSP_USP_USD { base srv6-endpoint-type; description "End SID with the REPLACE-CSID PSP/USP/USD flavor"; reference "RFC 9800"; Raza, et al. Expires 8 January 2026 [Page 43] Internet-Draft YANG Data Model for SRv6 July 2025 // RFC Editor: replace with actual RFC number and remove this // note } identity END.X.REPLACE-CSID_USD { base srv6-endpoint-type; description "End.X SID with the REPLACE-CSID USD flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.X.REPLACE-CSID_PSP_USD { base srv6-endpoint-type; description "End.X SID with the REPLACE-CSID PSP/USD flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.X.REPLACE-CSID_USP_USD { base srv6-endpoint-type; description "End.X SID with the REPLACE-CSID USP/USD flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } identity END.X.REPLACE-CSID_PSP_USP_USD { base srv6-endpoint-type; description "End.X SID with the REPLACE-CSID PSP/USP/USD flavor"; reference "RFC 9800"; // RFC Editor: replace with actual RFC number and remove this // note } // TODO: End.T w/ REPLACE-CSID *USD // TODO: End.DX1* Raza, et al. Expires 8 January 2026 [Page 44] Internet-Draft YANG Data Model for SRv6 July 2025 /* Endpoints defined under * draft-ietf-spring-sr-service-programming */ identity End.AN { base srv6-endpoint-type; description "Service-Chaining SR Aware function (native)"; reference "draft-ietf-spring-sr-service-programming-05"; // RFC Editor: replace with actual RFC number and remove this // note } identity End.AS { base srv6-endpoint-type; description "Service-Chaining Static proxy"; reference "draft-ietf-spring-sr-service-programming-05"; // RFC Editor: replace with actual RFC number and remove this // note } identity End.AD { base srv6-endpoint-type; description "Service-Chaining Dynamic proxy"; reference "draft-ietf-spring-sr-service-programming-05"; // RFC Editor: replace with actual RFC number and remove this // note } identity End.AM { base srv6-endpoint-type; description "Service-Chaining Masquerading SR proxy"; reference "draft-ietf-spring-sr-service-programming-05"; // RFC Editor: replace with actual RFC number and remove this // note } identity End.AM_NAT { base srv6-endpoint-type; description "Service-Chaining Masquerading SR proxy with NAT"; reference Raza, et al. Expires 8 January 2026 [Page 45] Internet-Draft YANG Data Model for SRv6 July 2025 "draft-ietf-spring-sr-service-programming-05"; // RFC Editor: replace with actual RFC number and remove this // note } identity End.AM_CACHE { base srv6-endpoint-type; description "Service-Chaining Masquerading SR proxy with Caching"; reference "draft-ietf-spring-sr-service-programming-05"; // RFC Editor: replace with actual RFC number and remove this // note } identity End.AM_NAT_CACHE { base srv6-endpoint-type; description "Service-Chaining Masquerading SR proxy with NAT and Caching"; reference "draft-ietf-spring-sr-service-programming-05"; // RFC Editor: replace with actual RFC number and remove this // note } identity srv6-headend-type { description "Base identity from which SRv6 headend rule types are derived."; } identity H.Encaps { base srv6-headend-type; description "Headend rule H.Encaps with encapsulated of an SRv6 policy"; reference "draft-ietf-spring-srv6-network-programming-16"; // RFC Editor: replace with actual RFC number and remove this // note } identity H.Encaps.Red { base srv6-headend-type; description "Headend rule H.Encaps.Red with reduced encap of an SRv6 policy"; reference Raza, et al. Expires 8 January 2026 [Page 46] Internet-Draft YANG Data Model for SRv6 July 2025 "draft-ietf-spring-srv6-network-programming-16"; // RFC Editor: replace with actual RFC number and remove this // note } identity H.Encaps.L2 { base srv6-headend-type; description "Headend rule H.Encaps.l2 on the received L2 frame"; reference "draft-ietf-spring-srv6-network-programming-16"; // RFC Editor: replace with actual RFC number and remove this // note } identity H.Encaps.L2.Red { base srv6-headend-type; description "Headend rule H.Encaps.L2.Red on the received L2 frame"; reference "draft-ietf-spring-srv6-network-programming-16"; // RFC Editor: replace with actual RFC number and remove this // note } identity srv6-security-type { description "Base identity from which SRv6 Security rule types are derived."; } identity EXTIF-ACL-DROP-DA-SIDSPACE { base srv6-security-type; description "Support an ACL on the external interface that drops any traffic with DA within the internal SID space."; reference "RFC 8754 section 5.1"; } identity INTIF-ACL-DROP-DA-SIDSPACE-SA-EXT { base srv6-security-type; description "Support an ACL that drops any traffic on mySID as DA from a source SA that does not belong to internal address or SID space.)"; reference "RFC 8754 section 5.1"; Raza, et al. Expires 8 January 2026 [Page 47] Internet-Draft YANG Data Model for SRv6 July 2025 } identity srv6-counter-type { description "Base identity from which SRv6 counter types are derived."; } identity CNT-MySID-Success { base srv6-counter-type; description "Count packets and bytes traffic that matched mySID and was processed successfully"; reference "RFC 8986 section 6"; } typedef srv6-sid { type inet:ipv6-prefix; description "This type defines a SID value in SRv6"; } typedef srv6-sid-compression-type { type enumeration { enum uncompressed { value 1; description "Uncompressed"; } enum csid-next { description "Compressed NEXT-CSID (aka uSID)"; } enum csid-replace { description "Compressed REPLACE-CSID"; } } description "SID [compression] type"; } typedef srv6-sid-func-value { type uint32; description "This is a typedef for SID's FUNC value"; } typedef srv6-sid-func-value-reserved-type { type enumeration { enum invalid { value 0; description "Invalid function value"; } } description "SRv6 SID's FUNC Reserved values"; } Raza, et al. Expires 8 January 2026 [Page 48] Internet-Draft YANG Data Model for SRv6 July 2025 typedef srv6-locator-name-type { type string { length "1..59"; } description "SRv6 locator name"; } typedef srv6-locator-len { type uint8 { range "16 .. 96"; } description "This type defines an SRv6 locator len with range constraints"; } typedef srv6-locator-block-len { type uint8; description "This type defines an SRv6 locator block length in bits"; } typedef srv6-locator-node-len { type uint8; description "This type defines an SRv6 locator node length in bits"; } typedef srv6-sid-func-len { type uint8; description "This type defines an SRv6 SID function length in bits"; } typedef srv6-sid-arg-len { type uint8; description "This type defines an SRv6 SID argument length in bits"; } typedef srv6-sid-pfxlen { type uint8 { range "16 .. 128"; } default 128; description "This type defines a SID prefixlen with range constraints"; } Raza, et al. Expires 8 January 2026 [Page 49] Internet-Draft YANG Data Model for SRv6 July 2025 typedef sid-alloc-type { type enumeration { enum Dynamic { description "SID allocated dynamically."; } enum Explicit { description "SID allocated with explicit (static) value"; } } description "Types of sid allocation used."; } identity srv6-sid-owner-type { description "Base identity from which SID owner types are derived."; } identity isis { base srv6-sid-owner-type; description "ISIS"; } identity ospfv3 { base srv6-sid-owner-type; description "OSPFv3"; } identity bgp { base srv6-sid-owner-type; description "BGP"; } identity evpn { base srv6-sid-owner-type; description "EVPN"; } identity sr-policy { base srv6-sid-owner-type; description "SR Policy"; } identity service-function { base srv6-sid-owner-type; description "SF"; Raza, et al. Expires 8 January 2026 [Page 50] Internet-Draft YANG Data Model for SRv6 July 2025 } identity static { base srv6-sid-owner-type; description "Static"; } typedef table-id { type uint32; description "Routing/switching/bridging/VLAN Table Id"; } typedef srv6-status-type { type enumeration { enum up { value 1; description "State is Up"; } enum down { description "State is Down"; } } description "Status type"; } typedef srv6-nexthop-type { type enumeration { enum ipv4 { value 1; description "IPv4 next-hop"; } enum ipv6 { description "IPv6 next-hop"; } enum mpls { description "MPLS next-hop"; } enum l3_lookup { description "L3 Lookup in a table"; } enum l2 { description "L2 next-hop"; } enum l2_lookup { description "L2 Lookup in a table"; } } description "Forwarding Next-hop type"; } grouping srv6-sid-structure-grouping { description "SRv6 SID structure grouping"; leaf locator-block-length { type srv6-types:srv6-locator-block-len; description "SRv6 SID locator block length in bits"; } leaf locator-node-length { type srv6-types:srv6-locator-node-len; description "SRv6 SID locator node length in bits"; } leaf function-length { type srv6-types:srv6-sid-func-len; Raza, et al. Expires 8 January 2026 [Page 51] Internet-Draft YANG Data Model for SRv6 July 2025 description "SRv6 SID function length in bits"; } leaf argument-length { type srv6-types:srv6-sid-arg-len; description "SRv6 SID argument length in bits"; } } grouping srv6-sid-structure-info-grouping { description "SRv6 SID structure info grouping"; container sid-structure { config false; description "SID structure container"; uses srv6-sid-structure-grouping; } } // Base identity for SID formats identity srv6-sid-format-type { description "Base identity from which SID format types are derived."; } identity srv6-sid-fmt-uc-1 { base srv6-sid-format-type; description "Uncompressed SID format with LBL=40, LNL=24, FL=16, and AL=16 or more. The locator length for this format is 64 bits."; } identity srv6-sid-fmt-uc-128 { base srv6-sid-format-type; description "Uncompressed SID format that allows flexible values for LBL/LNL/FL/AL."; } identity srv6-sid-fmt-cnext-1616 { base srv6-sid-format-type; description "Compressed NEXT-CSID format using LBL=16, LNL=16, FL=16 (or 32 for wide function), and AL=16 or more. The locator length for this format is 32 bits."; } identity srv6-sid-fmt-cnext-3216 { base srv6-sid-format-type; description "Compressed NEXT-CSID format using LBL=32, LNL=16, Raza, et al. Expires 8 January 2026 [Page 52] Internet-Draft YANG Data Model for SRv6 July 2025 FL=16 (or 32 for wide function), and AL=16 or more. The locator length for this format is 48 bits."; } identity srv6-sid-fmt-cnext-4816 { base srv6-sid-format-type; description "Compressed NEXT-CSID format using LBL=48, LNL=16, FL=16 (or 32 for wide function), and AL=16 or more. The locator length for this format is 64 bits."; } identity srv6-sid-fmt-cnext-6416 { base srv6-sid-format-type; description "Compressed NEXT-CSID format using LBL=64, LNL=16, FL=16 (or 32 for wide function), and AL=16 or more. The locator length for this format is 80 bits."; } // TODO: srv6-sid-fmt-crepl-XYZ } // module Figure 7: ietf-srv6-types.yang 6.2. SRv6 Base This YANG module imports types defined in [RFC6991], [RFC8294], [RFC8343], and [RFC8349]. file "ietf-srv6-base@2025-07-07.yang" // RFC Editor: replace the above date with the date of // publication and remove this note. module ietf-srv6-base { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-srv6-base"; prefix srv6; import ietf-interfaces { prefix "if"; reference "RFC 8343: A YANG Data Model for Interface Management"; } import ietf-inet-types { prefix inet; reference "RFC 6991: Common YANG Data Types"; } Raza, et al. Expires 8 January 2026 [Page 53] Internet-Draft YANG Data Model for SRv6 July 2025 import ietf-yang-types { prefix "yang"; reference "RFC 6991: Common YANG Data Types"; } import ietf-routing-types { prefix "rt-types"; reference "RFC 8294: Common YANG Data Types for the Routing Area"; } import ietf-routing { prefix "rt"; reference "RFC 8349: A YANG Data Model for Routing Management (NMDA version)"; } import ietf-segment-routing { prefix sr; reference "draft-ietf-spring-sr-yang"; } import ietf-srv6-types { prefix srv6-types; reference "RFC XXXX: YANG Data Model for SRv6"; // RFC Editor: replace XXXX with actual RFC number and remove // this note } organization "IETF SPRING Working Group"; contact "WG Web: WG List: Editor: Kamran Raza Editor: Jaganbabu Rajamanickam Editor: Xufeng Liu Editor: Zhibo Hu Editor: Iftekhar Hussain Raza, et al. Expires 8 January 2026 [Page 54] Internet-Draft YANG Data Model for SRv6 July 2025 Editor: Himanshu Shah Editor: Daniel Voyer Editor: Hani Elmalky Editor: Satoru Matsushima Editor: Katsuhiro Horiba Editor: Ahmed AbdelSalam Editor: Pingping Yu "; description "This YANG module defines the essential elements for the management of Segment-Routing with IPv6 dataplane (SRv6). Copyright (c) 2017 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 Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (http://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 2025-07-07 { description "Adding compressed SID and few other missing def"; reference "RFC XXXX: YANG Data Model for SRv6"; Raza, et al. Expires 8 January 2026 [Page 55] Internet-Draft YANG Data Model for SRv6 July 2025 // RFC Editor: replace XXXX with actual RFC number and remove // this note } revision 2022-01-14 { description "Alignment with SRv6 network programming rev16"; reference "RFC XXXX: YANG Data Model for SRv6"; // RFC Editor: replace XXXX with actual RFC number and remove // this note } revision 2019-10-30 { description "Alignment with SRv6 network programming"; reference "RFC XXXX: YANG Data Model for SRv6"; // RFC Editor: replace XXXX with actual RFC number and remove // this note } revision 2019-07-08 { description "Alignment with SRv6 network programming"; reference "RFC XXXX: YANG Data Model for SRv6"; // RFC Editor: replace XXXX with actual RFC number and remove // this note } revision 2018-10-22 { description "Initial revision."; reference "RFC XXXX: YANG Data Model for SRv6"; // RFC Editor: replace XXXX with actual RFC number and remove // this note } /* * Common */ grouping path-attrs-cmn { description "Path properties -common for v4/v6"; Raza, et al. Expires 8 January 2026 [Page 56] Internet-Draft YANG Data Model for SRv6 July 2025 leaf weight { type uint32; description "This value is used to compute a loadshare to perform un-equal load balancing when multiple outgoing path(s) are specified. A share is computed as a ratio of this number to the total under all configured path(s)."; } leaf role { type enumeration { enum PRIMARY { description "Path as primary traffic carrying"; } enum BACKUP { description "Path acts as a backup"; } enum PRIMARY_AND_BACKUP { description "Path acts as primary and backup simultaneously"; } } description "The path role"; } leaf backup-path-index { type uint8; description "Index of the protecting (backup) path"; } } grouping path-out-sids { description "Grouping for path's SID stack"; list out-sid { key "sid"; description "Out SID"; leaf sid { type srv6-types:srv6-sid; description "SID value"; } } } grouping path-out-labels { description "Grouping for path's label stack"; list out-label { key "label"; description "Out label"; leaf label { type rt-types:mpls-label; Raza, et al. Expires 8 January 2026 [Page 57] Internet-Draft YANG Data Model for SRv6 July 2025 description "Label value"; } } } /* * Config and State */ grouping srv6-encap { description "Grouping for encap param config."; container encapsulation { description "Configure encapsulation related parameters"; leaf source-address { type inet:ipv6-address; description "Specify a source address (for T.Encap). The address must locally exists and be routable"; } container hop-limit { description "Configure IPv6 header's Hop-limit options"; leaf value { when "../propagate = 'false'"; type uint8; default 64; description "Set encapsulating outer IPv6 header's Hoplimit field to specified value when doing encapsulation"; } leaf propagate { type boolean; default false; description "IP TTL/Hop-limit propagation from encapsulated packet to encapsulating outer IPv6 header's Hoplimit field. When configured on decapsulation side, this refers to propagating Hop-limit from outer IPv6 header to inner header after decap"; } } container traffic-class { description "Configure IPv6 header's Traffic-class options"; leaf value { when "../propagate = 'false'"; type uint8; default 0; Raza, et al. Expires 8 January 2026 [Page 58] Internet-Draft YANG Data Model for SRv6 July 2025 description "Set encapsulating outer IPv6 header's Traffic-class field to specified value when doing encapsulation"; } leaf propagate { type boolean; default false; description "Propagate (or map) Traffic-class/CoS/PCP from the incoming packet or L2 Ethernet frame being encapsulated to the encapsulating IPv6 header's Traffic-class field."; } } } } grouping srv6-ucsid16-cfg-grouping { description "Uncompressed 16 bit FUNCT SID format config grouping"; container id-block { description "Container for Id allocation corresponding to FUNCT"; reference "RFC XXXX: YANG Data Model for SRv6 - Section 3.4.1"; container explicit { description "Configure Explicit FUNCT parameters"; leaf start { type uint16; description "Start of explicit block"; } leaf size { type uint16; description "Size of explicit block"; } } } } grouping srv6-csid-next16-cfg-grouping { description "NEXT-CSID (16b uSID) common grouping"; // CFG container local-id-block { description "Configure LIB parameters"; reference "RFC XXXX: YANG Data Model for SRv6 - Section 3.4.2"; Raza, et al. Expires 8 January 2026 [Page 59] Internet-Draft YANG Data Model for SRv6 July 2025 leaf start { type uint16; // TODO: range description "LIB space follows GIB space. An implementation may chose the default index for the start of LIB - e.g. LIB starting from 0xE000. This configuration item allows to change the start of LIB space as a user wishes to resize (expand or shrink) it"; } container explicit { description "Configure Explicit LIB parameters"; leaf start { type uint16; description "Start of explicit LIB within LIB space"; } leaf size { type uint16; description "Size (to shrink or expand) of explicit LIB"; } } } } /* TODO grouping srv6-csid-replace-cfg-grouping { description "REPLACE-CSID common grouping"; // TODO CFG } */ grouping srv6-sid-formats { description "SRv6 SID formats grouping"; container sid-formats { description "Container for SRv6 SID formats"; list format { key "type"; description "SRv6 SID format"; leaf type { type identityref { base srv6-types:srv6-sid-format-type; } description "Format type"; } // STATE leaf compression-type { Raza, et al. Expires 8 January 2026 [Page 60] Internet-Draft YANG Data Model for SRv6 July 2025 type srv6-types:srv6-sid-compression-type; config false; description "Compression type"; } leaf description { type string; config false; description "Format description"; } uses srv6-types:srv6-sid-structure-info-grouping; // CFG container uncompressed-16 { when "derived-from-or-self(../type, 'srv6-sid-fmt-uc-1')" { description "This container is valid only when the SID format is one of the uncompressed types"; } description "Configuration specific to uncompressed SID formats with 16b FUNCT"; uses srv6-ucsid16-cfg-grouping; } container csid-next-16 { when "derived-from-or-self(../type, 'srv6-sid-fmt-cnext-1616') or derived-from-or-self(../type, 'srv6-sid-fmt-cnext-3216') or derived-from-or-self(../type, 'srv6-sid-fmt-cnext-6416')" { description "This container is valid only when the SID format is one of the 16bits NEXT-CSID"; } description "Configuration specific to NEXT-CSID with 16b CSIDs"; uses srv6-csid-next16-cfg-grouping; } container csid-replace { // TODO: when clause if/as needed description "REPLACE-CSID specific items"; // TODO: uses srv6-csid-replace-cfg-grouping; } } } } grouping srv6-locator-state { description "SRv6 grouping Locator state"; leaf operational-status { Raza, et al. Expires 8 January 2026 [Page 61] Internet-Draft YANG Data Model for SRv6 July 2025 type srv6-types:srv6-status-type; config false; description "Indicates whether locator state is UP"; } leaf is-in-address-conflict { type boolean; config false; description "Indicates whether locator address conflicts with some other IPv6 address on the box"; } } grouping srv6-remote-locator-stats-grouping { description "SRv6 Locator prefix accounting grouping"; container traffic-accounting { description "SRv6 remote locator traffic accounting"; container inbound { description "Per-Locator prefix inbound accounting"; uses srv6-stats-in; } container outbound { description "Per-Locator prefix per-nexthop counters (aka LOC.INT.E)"; list paths { key "interface next-hop"; description "Forwarding path information"; leaf interface { type if:interface-ref; description "The outgoing interface"; } leaf next-hop { type inet:ipv6-address; description "The IPv6 address of the next-hop"; } uses srv6-stats-out; } } } } Raza, et al. Expires 8 January 2026 [Page 62] Internet-Draft YANG Data Model for SRv6 July 2025 grouping srv6-remote-locators-state { description "SRv6 Remote Locator state grouping"; list remote { key "prefix"; config false; description "SRv6 remote locators' prefixes"; leaf prefix { type inet:ipv6-prefix; description "Locator IPv6 prefix"; } uses srv6-remote-locator-stats-grouping; } } grouping srv6-locators { description "SRv6 locator grouping"; container locators { description "SRv6 locators"; list locator { key "name"; description "Configure a SRv6 locator"; leaf name { type srv6-types:srv6-locator-name-type; description "Locator name"; } leaf enable { type boolean; default false; description "Enable a SRv6 locator"; } leaf format { type identityref { base srv6-types:srv6-sid-format-type; } mandatory true; description "SRv6 SID format"; } container prefix { description "Specify locator prefix value"; leaf address { Raza, et al. Expires 8 January 2026 [Page 63] Internet-Draft YANG Data Model for SRv6 July 2025 type inet:ipv6-address; mandatory true; description "IPv6 address"; } leaf length { type srv6-types:srv6-locator-len; mandatory true; description "Locator (prefix) length"; } } leaf algorithm { type uint8 { range "128..255"; } description "Algorithm Id (for Flex-Algo)"; } leaf anycast { type boolean; default false; description "Set to true if locator is an Anycast locator"; } container node-sid-auto-allocation { description "Container for SID auto allocation"; leaf behavior { type identityref { base srv6-types:srv6-endpoint-type; } description "As locator becomes operational, Node SIDs can be auto allocated - e.g. in Uncompressed format locator, a reserved FUNC value can be used and assigned for END SID; In NEXT-CSID, the locator prefix address is used as NEXT-CSID's END. These node SID are auto allocated with a default variant (e.g. PSP-USD). This item allows a user to specify a different variant."; } leaf disable { type boolean; default false; description "Set to true to disable auto allocation of SIDs"; } } uses srv6-locator-state; } Raza, et al. Expires 8 January 2026 [Page 64] Internet-Draft YANG Data Model for SRv6 July 2025 uses srv6-remote-locators-state; } } grouping srv6-stats-in { description "Grouping for inbound stats"; leaf in-pkts { type yang:counter64; description "A cumulative counter of the total number of packets received"; } leaf in-octets { type yang:counter64; description "A cumulative counter of the total bytes received."; } } grouping srv6-stats-out { description "Grouping for inbound stats"; leaf out-pkts { type yang:counter64; description "A cumulative counter of the total number of packets transmitted"; } leaf out-octets { type yang:counter64; description "A cumulative counter of the total bytes transmitted."; } } grouping path-out-sids-choice { description "Grouping for Out-SID choices"; choice encap-type { description "Out-SID encap-based choice"; case srv6 { uses path-out-sids; } case mpls { uses path-out-labels; } Raza, et al. Expires 8 January 2026 [Page 65] Internet-Draft YANG Data Model for SRv6 July 2025 } } grouping local-sid-fwd-state { description "SRv6 local-SID forwarding state grouping"; container forwarding { description "SRv6 local-SID forwarding state"; leaf is-installed { type boolean; description "Indicates whether SID is installed in forwarding"; } leaf next-hop-type { type srv6-types:srv6-nexthop-type; description "Forwarding next-hop types"; } container paths { when "../is-installed = 'true'" { description "This container is valid only when the local-SID is installed in forwarding"; } list path { key path-index; description "The list of paths associated with the SID"; leaf path-index { type uint8; description "Index of the path"; } container l2 { leaf interface { when "../../../../next-hop-type = 'l2'" { description "This leaf is valid only when the nexthop type is l2"; } type if:interface-ref; description "The outgoing Layer2 interface"; } leaf lookup-table-id { when "../../../../next-hop-type = 'l2_lookup'" { Raza, et al. Expires 8 January 2026 [Page 66] Internet-Draft YANG Data Model for SRv6 July 2025 description "This leaf is valid only when the nexthop type is L2 lookup (in a table)"; } type uint32; description "Lookup Table ID; Applicable to L2 VLAN, L2 Ucast/Mcast table"; } description "L2 information"; } container l3 { when "../../../next-hop-type = 'ipv4' or ../../../next-hop-type = 'ipv6'" { description "This container is valid only for L3 type of NHs"; } leaf interface { type if:interface-ref; description "The outgoing Layer3 interface"; } leaf next-hop { type inet:ip-address; description "The IP address of the next-hop"; } uses path-attrs-cmn; leaf lookup-table-id { when "../../../../next-hop-type = 'l3_lookup'" { description "This leaf is valid only when the nexthop type is L3 lookup (in a table)"; } type uint32; description "L3 Lookup Table ID; Applicable to L3 unicast table"; } //leaf vrf-name { // type string; // description " vrf name"; //} description "L3 information"; } uses path-out-sids-choice; Raza, et al. Expires 8 January 2026 [Page 67] Internet-Draft YANG Data Model for SRv6 July 2025 } description "Forwarding paths"; } } } grouping srv6-sid-alloc-grouping { description "SRv6 SID allocation grouping"; container allocation { description "SRv6 SID allocation container."; leaf alloc-type { type srv6-types:sid-alloc-type; description "Type of sid allocation."; } list owner { key "type instance"; description "SID Owner clients"; leaf type { type identityref { base srv6-types:srv6-sid-owner-type; } description "SID owner/client type"; } leaf instance { type string; description "Client instance"; } leaf is-winner { type boolean; description "Is this client/owner the winning in terms of forwarding"; } } leaf allocated-from-reserved { type boolean; description "Set to true if SID comes from reserved pool"; } } } grouping srv6-state-sid { description "SRv6 SID state grouping"; Raza, et al. Expires 8 January 2026 [Page 68] Internet-Draft YANG Data Model for SRv6 July 2025 container sids { description "My SID state"; leaf sid-holdtime { type uint8 { range "0..60"; //The range of minutes is from 0 (disabled) to 60 minutes } units minutes; default 30; description "The holdtime for a stale or freed SID. The value 0 is used for an immediate release of an allocated SID."; } container counts { config false; description "Summary/aggregate counts for my SIDs"; leaf allocated { type uint32; description "Total number of currently allocated SID"; } leaf stale { type uint32; description "A stale SID is the a previously allocated SID which is freed by the owner but not fully released due to holdtime"; } } list sid { key "sid"; config false; description "Per-SID"; leaf sid { type srv6-types:srv6-sid; description "My SID value"; } leaf behavior { type identityref { base srv6-types:srv6-endpoint-type; } description "Type of SRv6 endpoint behavior."; } Raza, et al. Expires 8 January 2026 [Page 69] Internet-Draft YANG Data Model for SRv6 July 2025 uses srv6-locator; uses srv6-sid-alloc-grouping; uses local-sid-fwd-state; container counters { description "SRv6 per SID counters"; container success { description "Counts SRv6 traffic received on local-SID prefix and processed successfully - see srv6-counter-types:CNT-MySID-Success (RFC 8986 section 6)"; uses srv6-stats-in; } } } } } grouping srv6-support-ends { description "SRv6 End behavior support grouping"; list end-behavior { key "type"; description "End behavior support"; leaf type { type identityref { base srv6-types:srv6-endpoint-type; } description "End behavior (End*) type"; } leaf supported { type boolean; mandatory true; description "True if supported"; } } } grouping srv6-support-headends { description "SRv6 Headend behavior support grouping"; list headend-behavior { key "type"; description "Headend behavior support"; leaf type { type identityref { base srv6-types:srv6-headend-type; } description "Headend behavior (H*) type"; } Raza, et al. Expires 8 January 2026 [Page 70] Internet-Draft YANG Data Model for SRv6 July 2025 leaf supported { type boolean; mandatory true; description "True if supported"; } } } grouping srv6-msd-signaled { description "SRv6 MSD signaled parameter support grouping"; container msd { description "SRv6 signaled MSD parameter support"; leaf max-sl { type uint8; description "Maximum value of the SL field in the SRH of a received packet before applying the Endpoint behavior associated with a SID"; } leaf max-end-pop { type uint8; description "Maximum number of SIDs in the top SRH in an SRH stack to which the router can apply PSP or USP flavors"; } leaf max-h_encap { type uint8; description "Maximum number of SIDs that can be pushed as part of the H.Encaps* behavior"; } leaf max-end_d { type uint8; description "Maximum number of SIDs in an SRH when applying End.D* behaviors (e.g. End.X6 and End.DT6)"; } } } grouping srv6-support-security-rules { description "SRv6 Security rules grouping"; list security-rule { key "type"; description "Security rule support"; leaf type { type identityref { base srv6-types:srv6-security-type; } Raza, et al. Expires 8 January 2026 [Page 71] Internet-Draft YANG Data Model for SRv6 July 2025 description "Security rule type"; } leaf supported { type boolean; mandatory true; description "True if supported"; } } } grouping srv6-support-counters { description "SRv6 Counters grouping"; list counters { key "type"; description "SRv6 counter support"; leaf type { type identityref { base srv6-types:srv6-counter-type; } description "Counter type"; } leaf supported { type boolean; mandatory true; description "True if supported"; } } } grouping srv6-state-capabilities { description "SRv6 node capabilities grouping"; container node-capabilities { config false; description "Node's SRv6 capabilities"; uses srv6-support-ends; uses srv6-support-headends; uses srv6-msd-signaled; uses srv6-support-security-rules; uses srv6-support-counters; } } augment "/rt:routing/sr:segment-routing" { description "This augments Segment Routing (SR) with SRv6."; container srv6 { description "Segment Routing with IPv6 dataplane"; Raza, et al. Expires 8 January 2026 [Page 72] Internet-Draft YANG Data Model for SRv6 July 2025 /* config */ leaf enable { type boolean; default false; description "Enable SRv6"; } uses srv6-state-capabilities; uses srv6-encap; uses srv6-sid-formats; uses srv6-locators; uses srv6-state-sid; } } /* Notifications */ grouping srv6-locator { description "An absolute reference to an SRv6 locator"; leaf locator { type leafref { path "/rt:routing/sr:segment-routing/srv6:srv6/srv6:locators/srv6:locator/srv6:name"; } description "Reference to a SRv6 locator."; } } notification srv6-locator-status-event { description "Notification event for a change of SRv6 locator operational status."; leaf operational-status { type srv6-types:srv6-status-type; description "Operational status"; } uses srv6-locator; } notification srv6-sid-collision-event { description "Notification event for an SRv6 SID collision - i.e., attempt to bind an already bound SID to a new context"; leaf sid { type srv6-types:srv6-sid; description "SRv6 SID"; } container existing { Raza, et al. Expires 8 January 2026 [Page 73] Internet-Draft YANG Data Model for SRv6 July 2025 description "Current assignment / bind"; leaf end-behavior-type { type identityref { base srv6-types:srv6-endpoint-type; } description "End type"; } list owner { key "type instance"; description "SID Owner clients"; leaf type { type identityref { base srv6-types:srv6-sid-owner-type; } description "SID owner/client type"; } leaf instance { type string; description "Client instance"; } } } container requested { description "Requested assignment / bind"; leaf end-behavior-type { type identityref { base srv6-types:srv6-endpoint-type; } description "End type"; } container requester { description "SID client"; leaf type { type identityref { base srv6-types:srv6-sid-owner-type; } description "SID owner/client type"; } leaf instance { type string; description "Client instance"; } } } } } // module Raza, et al. Expires 8 January 2026 [Page 74] Internet-Draft YANG Data Model for SRv6 July 2025 Figure 8: ietf-srv6-base.yang 6.3. SRv6 Static This YANG module imports types defined in [RFC6991], [RFC8343], and [RFC8349]. file "ietf-srv6-static@2025-07-07.yang" // RFC Editor: replace the above date with the date of // publication and remove this note. module ietf-srv6-static { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-srv6-static"; prefix srv6-static; import ietf-interfaces { prefix "if"; reference "RFC 8343: A YANG Data Model for Interface Management"; } import ietf-inet-types { prefix inet; reference "RFC 6991: Common YANG Data Types"; } import ietf-routing { prefix "rt"; reference "RFC 8349: A YANG Data Model for Routing Management (NMDA version)"; } import ietf-segment-routing { prefix sr; reference "draft-ietf-spring-sr-yang"; } import ietf-srv6-types { prefix srv6-types; reference "RFC XXXX: YANG Data Model for SRv6"; // RFC Editor: replace XXXX with actual RFC number and remove // this note } import ietf-srv6-base { prefix srv6; Raza, et al. Expires 8 January 2026 [Page 75] Internet-Draft YANG Data Model for SRv6 July 2025 reference "RFC XXXX: YANG Data Model for SRv6"; // RFC Editor: replace XXXX with actual RFC number and remove // this note } organization "IETF SPRING Working Group"; contact "WG Web: WG List: Editor: Kamran Raza Editor: Jaganbabu Rajamanickam Editor: Xufeng Liu Editor: Zhibo Hu Editor: Iftekhar Hussain Editor: Himanshu Shah Editor: Daniel Voyer Editor: Hani Elmalky Editor: Satoru Matsushima Editor: Katsuhiro Horiba Editor: Ahmed AbdelSalam Editor: Pingping Yu "; Raza, et al. Expires 8 January 2026 [Page 76] Internet-Draft YANG Data Model for SRv6 July 2025 description "This YANG module defines the essential elements for the management of Static application for Segment-Routing with IPv6 dataplane (SRv6). Copyright (c) 2018 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 Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (http://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 2025-07-07 { description "Renamed local-sid to sid"; reference "RFC XXXX: YANG Data Model for SRv6 Static"; // RFC Editor: replace XXXX with actual RFC number and remove // this note } revision 2024-03-04 { description "Fixed static yang warnings"; reference "RFC XXXX: YANG Data Model for SRv6"; // RFC Editor: replace XXXX with actual RFC number and remove // this note } revision 2022-01-14 { description "Alignment with SRv6 network programming rev16"; reference "RFC XXXX: YANG Data Model for SRv6"; // RFC Editor: replace XXXX with actual RFC number and remove // this note } Raza, et al. Expires 8 January 2026 [Page 77] Internet-Draft YANG Data Model for SRv6 July 2025 revision 2019-10-30 { description "Extended model for EVPN behaviors"; reference "RFC XXXX: YANG Data Model for SRv6"; // RFC Editor: replace XXXX with actual RFC number and remove // this note } revision 2019-07-08 { description "Alignment with SRv6 network programming"; reference "RFC XXXX: YANG Data Model for SRv6"; // RFC Editor: replace XXXX with actual RFC number and remove // this note } revision 2018-10-22 { description "Initial revision."; reference "RFC XXXX: YANG Data Model for SRv6"; // RFC Editor: replace XXXX with actual RFC number and remove // this note } /* * Config and State */ grouping path-attrs-v6 { description "IPv6 Path properties"; leaf interface { type if:interface-ref; description "The outgoing interface"; } leaf next-hop { type inet:ipv6-address; description "The IP address of the next-hop"; } leaf table { type srv6-types:table-id; Raza, et al. Expires 8 January 2026 [Page 78] Internet-Draft YANG Data Model for SRv6 July 2025 description "The routing table associated with the next-hop"; } uses srv6:path-attrs-cmn; } grouping path-attrs-v4 { description "IPv4 Path properties"; leaf interface { type if:interface-ref; description "The outgoing interface"; } leaf next-hop { type inet:ipv4-address; description "The IP address of the next-hop"; } leaf table { type srv6-types:table-id; description "The routing table associated with the next-hop"; } uses srv6:path-attrs-cmn; } grouping path-attrs-mpls { description "MPLS Path properties"; leaf interface { type if:interface-ref; description "The outgoing interface"; } leaf next-hop { type inet:ip-address; description "The IP address of the next-hop"; } uses srv6:path-attrs-cmn; } grouping multi-paths-v6 { description "Multipath grouping"; Raza, et al. Expires 8 January 2026 [Page 79] Internet-Draft YANG Data Model for SRv6 July 2025 container paths { description "List of outgoing paths"; list path { key path-index; description "The list of paths associated with the SID"; leaf path-index { type uint8; description "Index of the path"; } uses path-attrs-v6; container sid-list { description "SID-list associated with the path"; uses srv6:path-out-sids; } } } } grouping multi-paths-v4 { description "Multipath grouping"; container paths { description "List of outgoing paths"; list path { key path-index; description "The list of paths associated with the SID"; leaf path-index { type uint8; description "Index of the path"; } uses path-attrs-v4; container sid-list { description "SID-list associated with the path"; uses srv6:path-out-sids; } } } } grouping multi-paths-mpls { description "Multipath grouping"; container paths { description "List of outgoing paths"; Raza, et al. Expires 8 January 2026 [Page 80] Internet-Draft YANG Data Model for SRv6 July 2025 list path { key path-index; description "The list of paths associated with the SID"; leaf path-index { type uint8; description "Index of the path"; } uses path-attrs-mpls; container sid-list { description "SID-list associated with the path"; uses srv6:path-out-sids; } } } } grouping multi-paths-v6-BUM { description "Multipath grouping for EVPN bridging BUM use case"; container paths { description "List of outgoing paths for flooding"; list path { key path-index; description "The list of paths associated with the SID"; leaf path-index { type uint8; description "Index of the path"; } leaf l2-interface { type if:interface-ref; description "The outgoing L2 interface for flooding"; } } } } grouping srv6-sid-config { description "Configuration parameters relating to SRv6 sid."; leaf function { type srv6-types:srv6-sid-func-value; Raza, et al. Expires 8 January 2026 [Page 81] Internet-Draft YANG Data Model for SRv6 July 2025 description "SRv6 function value."; } leaf end-behavior-type { type identityref { base srv6-types:srv6-endpoint-type; } mandatory true; description "Type of SRv6 end behavior."; } container end { when "../end-behavior-type = 'srv6-types:End'" { description "This container is valid only when the user chooses End behavior (variant: no PSP, no USP)."; } description "The Endpoint function is the most basic function. FIB lookup on updated DA and forward accordingly to the matched entry. This is the SRv6 instantiation of a Prefix SID (variant: no PSP, no USP)"; } container end_psp { when "../end-behavior-type = 'srv6-types:End_PSP'" { description "This container is valid only when the user chooses End behavior (variant: PSP only)."; } description "The Endpoint function is the most basic function. FIB lookup on updated DA and forward accordingly to the matched entry. This is the SRv6 instantiation of a Prefix SID (variant: PSP only)"; } container end_usp { when "../end-behavior-type = 'srv6-types:End_USP'" { description "This container is valid only when the user chooses End behavior (variant: USP only)."; } Raza, et al. Expires 8 January 2026 [Page 82] Internet-Draft YANG Data Model for SRv6 July 2025 description "The Endpoint function is the most basic function. FIB lookup on updated DA and forward accordingly to the matched entry. This is the SRv6 instantiation of a Prefix SID (variant: USP only)"; } container end_psp_usp { when "../end-behavior-type = 'srv6-types:End_PSP_USP'" { description "This container is valid only when the user chooses End behavior (variant: PSP/USP)."; } description "The Endpoint function is the most basic function. FIB lookup on updated DA and forward accordingly to the matched entry. This is the SRv6 instantiation of a Prefix SID (variant: PSP/USP)"; } container end_usd { when "../end-behavior-type = 'srv6-types:End_USD'" { description "This container is valid only when the user chooses End behavior (variant: USD only)."; } description "The Endpoint function is the most basic function. FIB lookup on updated DA and forward accordingly to the matched entry. This is the SRv6 instantiation of a Prefix SID (variant: USD)"; } container end_psp_usd { when "../end-behavior-type = 'srv6-types:End_PSP_USD'" { description "This container is valid only when the user chooses End behavior (variant: PSP/USD)."; } description "The Endpoint function is the most basic function. FIB lookup on updated DA and forward accordingly to the matched entry. Raza, et al. Expires 8 January 2026 [Page 83] Internet-Draft YANG Data Model for SRv6 July 2025 This is the SRv6 instantiation of a Prefix SID (variant: PSP/USD)"; } container end_usp_usd { when "../end-behavior-type = 'srv6-types:End_USP_USD'" { description "This container is valid only when the user chooses End behavior (variant: USP/USD)."; } description "The Endpoint function is the most basic function. FIB lookup on updated DA and forward accordingly to the matched entry. This is the SRv6 instantiation of a Prefix SID (variant: USP/USD)"; } container end_psp_usp_usd { when "../end-behavior-type = 'srv6-types:End_PSP_USP_USD'" { description "This container is valid only when the user chooses End behavior (variant: PSP/USP/USD)."; } description "The Endpoint function is the most basic function. FIB lookup on updated DA and forward accordingly to the matched entry. This is the SRv6 instantiation of a Prefix SID (variant: PSP/USP/USD)"; } container end-t { when "../end-behavior-type = 'srv6-types:End.T'" { description "This container is valid only when the user chooses End.T behavior (variant: no PSP, no USP)."; } description "Endpoint with specific IPv6 table lookup (variant: no PSP, no USP). Lookup the next segment in IPv6 table T associated with the SID and forward via the matched table entry. The End.T is used for multi-table operation Raza, et al. Expires 8 January 2026 [Page 84] Internet-Draft YANG Data Model for SRv6 July 2025 in the core."; // TODO presence "Mandatory child only if container is present"; leaf lookup-table-ipv6 { type srv6-types:table-id; mandatory true; description "Table Id for lookup on updated DA (next segment)"; } } container end-t_psp { when "../end-behavior-type = 'srv6-types:End.T_PSP'" { description "This container is valid only when the user chooses End.T behavior (variant: PSP only)."; } description "Endpoint with specific IPv6 table lookup (variant: PSP only). Lookup the next segment in IPv6 table T associated with the SID and forward via the matched table entry. The End.T is used for multi-table operation in the core."; // TODO presence "Mandatory child only if container is present"; leaf lookup-table-ipv6 { type srv6-types:table-id; mandatory true; description "Table Id for lookup on updated DA (next segment)"; } } container end-t_usp { when "../end-behavior-type = 'srv6-types:End.T_USP'" { description "This container is valid only when the user chooses End.T behavior (variant: USP only)."; } description "Endpoint with specific IPv6 table lookup (variant: USP only). Lookup the next segment in IPv6 table T associated with the SID and forward via the matched table entry. The End.T is used for multi-table operation Raza, et al. Expires 8 January 2026 [Page 85] Internet-Draft YANG Data Model for SRv6 July 2025 in the core."; // TODO presence "Mandatory child only if container is present"; leaf lookup-table-ipv6 { type srv6-types:table-id; mandatory true; description "Table Id for lookup on updated DA (next segment)"; } } container end-t_psp_usp { when "../end-behavior-type = 'srv6-types:End.T_PSP_USP'" { description "This container is valid only when the user chooses End.T behavior (variant: USP/PSP)."; } description "Endpoint with specific IPv6 table lookup (variant: USP/PSP). Lookup the next segment in IPv6 table T associated with the SID and forward via the matched table entry. The End.T is used for multi-table operation in the core."; // TODO presence "Mandatory child only if container is present"; leaf lookup-table-ipv6 { type srv6-types:table-id; mandatory true; description "Table Id for lookup on updated DA (next segment)"; } } container end-t_usd { when "../end-behavior-type = 'srv6-types:End.T_USD'" { description "This container is valid only when the user chooses End.T behavior (variant: USD only)."; } description "Endpoint with specific IPv6 table lookup (variant: USD only). Lookup the next segment in IPv6 table T associated with the SID and forward via the matched table entry. The End.T is used for multi-table operation Raza, et al. Expires 8 January 2026 [Page 86] Internet-Draft YANG Data Model for SRv6 July 2025 in the core."; // TODO presence "Mandatory child only if container is present"; leaf lookup-table-ipv6 { type srv6-types:table-id; mandatory true; description "Table Id for lookup on updated DA (next segment)"; } } container end-t_psp_usd { when "../end-behavior-type = 'srv6-types:End.T_PSP_USD'" { description "This container is valid only when the user chooses End.T behavior (variant: PSP/USD only)."; } description "Endpoint with specific IPv6 table lookup (variant: PSP/USD only). Lookup the next segment in IPv6 table T associated with the SID and forward via the matched table entry. The End.T is used for multi-table operation in the core."; // TODO presence "Mandatory child only if container is present"; leaf lookup-table-ipv6 { type srv6-types:table-id; mandatory true; description "Table Id for lookup on updated DA (next segment)"; } } container end-t_usp_usd { when "../end-behavior-type = 'srv6-types:End.T_USP_USD'" { description "This container is valid only when the user chooses End.T behavior (variant: USP/USD only)."; } description "Endpoint with specific IPv6 table lookup (variant: USP/USD only). Lookup the next segment in IPv6 table T associated with the SID and forward via Raza, et al. Expires 8 January 2026 [Page 87] Internet-Draft YANG Data Model for SRv6 July 2025 the matched table entry. The End.T is used for multi-table operation in the core."; // TODO presence "Mandatory child only if container is present"; leaf lookup-table-ipv6 { type srv6-types:table-id; mandatory true; description "Table Id for lookup on updated DA (next segment)"; } } container end-t_psp_usp_usd { when "../end-behavior-type = 'srv6-types:End.T_PSP_USP_USD'" { description "This container is valid only when the user chooses End.T behavior (variant: USP only)."; } description "Endpoint with specific IPv6 table lookup (variant: PSP/USP/USD only). Lookup the next segment in IPv6 table T associated with the SID and forward via the matched table entry. The End.T is used for multi-table operation in the core."; // TODO presence "Mandatory child only if container is present"; leaf lookup-table-ipv6 { type srv6-types:table-id; mandatory true; description "Table Id for lookup on updated DA (next segment)"; } } container end-x { when "../end-behavior-type = 'srv6-types:End.X'" { description "This container is valid only when the user chooses End.X behavior (variant: no USP/PSP)"; } description "Endpoint with cross-connect to an array of layer-3 adjacencies (variant: no USP/PSP). Raza, et al. Expires 8 January 2026 [Page 88] Internet-Draft YANG Data Model for SRv6 July 2025 Forward to layer-3 adjacency bound to the SID S. The End.X function is required to express any traffic-engineering policy."; leaf protected { type boolean; default false; description "Is Adj-SID protected?"; } uses multi-paths-v6; } container end-x_psp { when "../end-behavior-type = 'srv6-types:End.X_PSP'" { description "This container is valid only when the user chooses End.X behavior (variant: PSP only)"; } description "Endpoint with cross-connect to an array of layer-3 adjacencies (variant: PSP only). Forward to layer-3 adjacency bound to the SID S. The End.X function is required to express any traffic-engineering policy."; leaf protected { type boolean; default false; description "Is Adj-SID protected?"; } uses multi-paths-v6; } container end-x_usp { when "../end-behavior-type = 'srv6-types:End.X_USP'" { description "This container is valid only when the user chooses End.X behavior (variant: USP only)"; } description "Endpoint with cross-connect to an array of layer-3 adjacencies (variant: USP only). Forward to layer-3 adjacency bound to the SID S. The End.X function is required to express any traffic-engineering policy."; Raza, et al. Expires 8 January 2026 [Page 89] Internet-Draft YANG Data Model for SRv6 July 2025 leaf protected { type boolean; default false; description "Is Adj-SID protected?"; } uses multi-paths-v6; } container end-x_psp_usp { when "../end-behavior-type = 'srv6-types:End.X_PSP_USP'" { description "This container is valid only when the user chooses End.X behavior (variant: PSP/USP)"; } description "Endpoint with cross-connect to an array of layer-3 adjacencies (variant: PSP/USP). Forward to layer-3 adjacency bound to the SID S. The End.X function is required to express any traffic-engineering policy."; leaf protected { type boolean; default false; description "Is Adj-SID protected?"; } uses multi-paths-v6; } container end-x_usd { when "../end-behavior-type = 'srv6-types:End.X_USD'" { description "This container is valid only when the user chooses End.X behavior (variant: USD only)"; } description "Endpoint with cross-connect to an array of layer-3 adjacencies (variant: PSP/USP). Forward to layer-3 adjacency bound to the SID S. The End.X function is required to express any traffic-engineering policy."; leaf protected { type boolean; default false; Raza, et al. Expires 8 January 2026 [Page 90] Internet-Draft YANG Data Model for SRv6 July 2025 description "Is Adj-SID protected?"; } uses multi-paths-v6; } container end-x_psp_usd { when "../end-behavior-type = 'srv6-types:End.X_PSP_USD'" { description "This container is valid only when the user chooses End.X behavior (variant: PSP/USD only)"; } description "Endpoint with cross-connect to an array of layer-3 adjacencies (variant: PSP/USP). Forward to layer-3 adjacency bound to the SID S. The End.X function is required to express any traffic-engineering policy."; leaf protected { type boolean; default false; description "Is Adj-SID protected?"; } uses multi-paths-v6; } container end-x_usp_usd { when "../end-behavior-type = 'srv6-types:End.X_USP_USD'" { description "This container is valid only when the user chooses End.X behavior (variant: USP/USD only)"; } description "Endpoint with cross-connect to an array of layer-3 adjacencies (variant: PSP/USP). Forward to layer-3 adjacency bound to the SID S. The End.X function is required to express any traffic-engineering policy."; leaf protected { type boolean; default false; description "Is Adj-SID protected?"; } uses multi-paths-v6; Raza, et al. Expires 8 January 2026 [Page 91] Internet-Draft YANG Data Model for SRv6 July 2025 } container end-x_psp_usp_usd { when "../end-behavior-type = 'srv6-types:End.X_PSP_USP_USD'" { description "This container is valid only when the user chooses End.X behavior (variant: PSP/USP/USD only)"; } description "Endpoint with cross-connect to an array of layer-3 adjacencies (variant: PSP/USP). Forward to layer-3 adjacency bound to the SID S. The End.X function is required to express any traffic-engineering policy."; leaf protected { type boolean; default false; description "Is Adj-SID protected?"; } uses multi-paths-v6; } container end-b6-encaps { when "../end-behavior-type = 'srv6-types:End.B6.Encaps' or ../end-behavior-type = 'srv6-types:End.B6.Encaps.Red'" { description "This container is valid only when the user chooses End.B6.Encaps or End.B6.Encaps.Red behavior."; } description "Endpoint bound to an SRv6 Policy. Insert SRH based on the policy and forward the packet toward the first hop configured in the policy. This is the SRv6 instantiation of a Binding SID. This behavior also adds an outer IPv6 header"; // TODO presence "Mandatory child only if container is present"; leaf policy-name { type string; mandatory true; description "SRv6 policy name."; } leaf source-address { type inet:ipv6-address; mandatory true; Raza, et al. Expires 8 January 2026 [Page 92] Internet-Draft YANG Data Model for SRv6 July 2025 description "IPv6 source address for Encap."; } uses multi-paths-v6; } container end-bm { when "../end-behavior-type = 'srv6-types:End.BM'" { description "This container is valid only when the user chooses End.BM behavior."; } description "Endpoint bound to an SR-MPLS Policy. push an MPLS label stack on the received packet and forward the according to Lable L1. This is an SRv6 instantiation of an SR-MPLS Binding SID."; // TODO presence "Mandatory child only if container is present"; leaf policy-name { type string; mandatory true; description "SRv6 policy name"; } uses multi-paths-mpls; } container end-dx6 { when "../end-behavior-type = 'srv6-types:End.DX6'" { description "This container is valid only when the user chooses End.DX6 behavior."; } description "Endpoint with decapsulation and cross-connect to an array of IPv6 adjacencies. Pop the (outer) IPv6 header and its extension headers and forward to layer-3 adjacency bound to the SID S. The End.DX6 used in the L3VPN use-case."; uses multi-paths-v6; // TODO: Backup path of type "Lookup in table" } Raza, et al. Expires 8 January 2026 [Page 93] Internet-Draft YANG Data Model for SRv6 July 2025 container end-dx4 { when "../end-behavior-type = 'srv6-types:End.DX4'" { description "This container is valid only when the user chooses End.DX4 behavior."; } description "Endpoint with decapsulation and cross-connect to an array of IPv4 adjacencies. Pop the (outer) IPv6 header and its extension header and forward to layer-3 adjacency bound to the SID S. This would be equivalent to the per-CE VPN label in MPLS."; uses multi-paths-v4; // TODO: Backup path of type "Lookup in table" } container end-dt6 { when "../end-behavior-type = 'srv6-types:End.DT6'" { description "This container is valid only when the user chooses End.DT6 behavior."; } description "Endpoint with decapsulation and specific IPv6 table lookup. Pop the (outer) IPv6 header and its extension headers. Lookup the exposed inner IPv6 DA in IPv6 table T and forward via the matched table entry. End.DT6 function is used in L3VPN use-case."; // TODO presence "Mandatory child only if container is present"; leaf lookup-table-ipv6 { type srv6-types:table-id; mandatory true; description "IPv6 table"; } } container end-dt4 { when "../end-behavior-type = 'srv6-types:End.DT4'" { description "This container is valid only when the user chooses End.DT4 behavior."; } description Raza, et al. Expires 8 January 2026 [Page 94] Internet-Draft YANG Data Model for SRv6 July 2025 "Endpoint with decapsulation and specific IPv4 table lookup. Pop the (outer) IPv6 header and its extension headers. Lookup the exposed inner IPv4 DA in IPv4 table T and forward via the matched table entry. This would be equivalent to the per-VRF VPN label in MPLS."; // TODO presence "Mandatory child only if container is present"; leaf lookup-table-ipv4 { type srv6-types:table-id; mandatory true; description "IPv4 table"; } } container end-dt46 { when "../end-behavior-type = 'srv6-types:End.DT46'" { description "This container is valid only when the user chooses End.DT46 behavior."; } description "Endpoint with decapsulation and specific IP table lookup. Depending on the protocol type (IPv4 or IPv6) of the inner ip packet and the specific VRF name forward the packet. This would be equivalent to the per-VRF VPN label in MPLS."; // TODO presence "Mandatory child only if container is present"; leaf lookup-table-ipv4 { type srv6-types:table-id; mandatory true; description "IPv4 table"; } leaf lookup-table-ipv6 { type srv6-types:table-id; mandatory true; description "IPv6 table"; } } /* EVPN END behavior types */ container end-dx2 { Raza, et al. Expires 8 January 2026 [Page 95] Internet-Draft YANG Data Model for SRv6 July 2025 when "../end-behavior-type = 'srv6-types:End.DX2'" { description "This container is valid only when the user chooses End.DX2 behavior."; } description "This is an Endpoint with decapsulation and Layer-2 cross-connect to OIF. Pop the (outer) IPv6 header and its extension headers. Forward the resulting frame via OIF associated to the SID. The End.DX2 function is the L2VPN/EVPN VPWS use-case."; container path { description "Outgoing path"; leaf l2-interface { type if:interface-ref; mandatory true; description "Outgoing L2 interface"; } } } container end-dx2v { when "../end-behavior-type = 'srv6-types:End.DX2V'" { description "This container is valid only when the user chooses End.DX2V behavior."; } description "Endpoint with decapsulation and specific VLAN L2 table lookup. Pop the (outer) IPv6 header and its extension headers. Lookup the exposed inner VLANs in L2 table T. Forward via the matched table entry. The End.DX2V is used for EVPN Flexible cross-connect use-cases"; leaf lookup-table-vlan { type srv6-types:table-id; mandatory true; description "VLAN lookup table. There could be multiple vlan demux tables on the node, where a DX2V SID points to one vlan table"; } } container end-dt2u { Raza, et al. Expires 8 January 2026 [Page 96] Internet-Draft YANG Data Model for SRv6 July 2025 when "../end-behavior-type = 'srv6-types:End.DT2U'" { description "This container is valid only when the user chooses End.DT2U behavior."; } description "Endpoint with decapsulation and specific unicast L2 MAC table lookup. Pop the (outer) IPv6 header and its extension headers. Learn the exposed inner MAC SA in L2 MAC table T. Lookup the exposed inner MAC DA in L2 MAC table T. Forward via the matched T entry else to all L2OIF in T. The End.DT2U is used for EVPN Bridging unicast use cases"; leaf lookup-table-mac { type srv6-types:table-id; mandatory true; description "MAC L2 lookup table"; } } container end-dt2m { when "../end-behavior-type = 'srv6-types:End.DT2M'" { description "This container is valid only when the user chooses End.DT2M behavior."; } description "Endpoint with decapsulation and specific flooding table. Pop the (outer) IPv6 header and its extension headers. Learn the exposed inner MAC SA in L2 MAC table T. Forward on all L2OIF (in the flooding table) excluding the one identfied by Arg.FE2. The End.DT2M is used for EVPN Bridging BUM use case with ESI (Split Horizon) filtering capability."; leaf flooding-table { type srv6-types:table-id; mandatory true; description "L2 Flooding table (list of OIFs)"; } uses multi-paths-v6-BUM; /* TODO - Support for argument Arg.FE2. It is an argument specific to EVPN ESI filtering and EVPN-ETREE used to exclude specific OIF (or set of OIFs) from flooding table. */ } Raza, et al. Expires 8 January 2026 [Page 97] Internet-Draft YANG Data Model for SRv6 July 2025 /* End of EVPN END behavior types */ } grouping srv6-static-sid-cfg { description "Grouping configuration and operation for SRv6 sid."; list sid { key "function"; description "List of locally instantiated SIDs"; uses srv6-sid-config; } } augment "/rt:routing/sr:segment-routing/srv6:srv6/srv6:locators/srv6:locator" { description "This augments locator leaf within SRv6."; container static { description "Static SRv6"; /* Local/My SIDs */ container sids { description "Locally instantiated explicit SRv6 SIDs"; uses srv6-static-sid-cfg; /* no state for now; SID state accessible through base model */ } } } } // module Figure 9: ietf-srv6-static.yang 7. Security Considerations The YANG module specified in this document defines a schema for data that is designed to be accessed via network management protocols such as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer is the secure transport layer, and the mandatory-to-implement secure transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer is HTTPS, and the mandatory-to-implement secure transport is TLS [RFC8446]. Raza, et al. Expires 8 January 2026 [Page 98] Internet-Draft YANG Data Model for SRv6 July 2025 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 all available NETCONF or RESTCONF protocol operations and content. There are a number of data nodes defined in this YANG module that are writable/creatable/ deletable (i.e., config true, which is the default). These data nodes may be considered sensitive or vulnerable in some network environments. Write operations (e.g., edit-config) to these data nodes without proper protection can have a negative effect on network operations. Some of the readable data nodes in this YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control read access (e.g., via get, get-config, or notification) to these data nodes. It goes without saying that this specification also inherits the security considerations captured in the SRv6 specification document [RFC8986]. 8. IANA Considerations This document requests the registration of the following URIs in the IETF "XML registry" [RFC3688]: +==============================================+============+=====+ | URI | Registrant | XML | +==============================================+============+=====+ | urn:ietf:params:xml:ns:yang:ietf-srv6-types | The IESG | N/A | +----------------------------------------------+------------+-----+ +----------------------------------------------+------------+-----+ | urn:ietf:params:xml:ns:yang:ietf-srv6-base | The IESG | N/A | +----------------------------------------------+------------+-----+ | urn:ietf:params:xml:ns:yang:ietf-srv6-static | The IESG | N/A | +----------------------------------------------+------------+-----+ Table 1 This document requests the registration of the following YANG modules in the "YANG Module Names" registry [RFC6020]: Raza, et al. Expires 8 January 2026 [Page 99] Internet-Draft YANG Data Model for SRv6 July 2025 +===========+=================================+===========+=========+ |Name |Namespace |Prefix |Reference| +===========+=================================+===========+=========+ |ietf- |urn:ietf:params:xml:ns:yang:ietf-|srv6-types |This | |srv6-types |srv6-types | |document | +-----------+---------------------------------+-----------+---------+ +-----------+---------------------------------+-----------+---------+ |ietf- |urn:ietf:params:xml:ns:yang:ietf-|srv6 |This | |srv6-base |srv6-base | |document | +-----------+---------------------------------+-----------+---------+ +-----------+---------------------------------+-----------+---------+ |ietf- |urn:ietf:params:xml:ns:yang:ietf-|srv6-static|This | |srv6-static|srv6-static | |document | +-----------+---------------------------------+-----------+---------+ Table 2 -- RFC Editor: Replace "This document" with the document RFC number at time of publication, and remove this note. 9. References 9.1. 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, . [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [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, . [RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011, . Raza, et al. Expires 8 January 2026 [Page 100] Internet-Draft YANG Data Model for SRv6 July 2025 [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013, . [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, . [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, . [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, . Raza, et al. Expires 8 January 2026 [Page 101] Internet-Draft YANG Data Model for SRv6 July 2025 [RFC8407] Bierman, A., "Guidelines for Authors and Reviewers of Documents Containing YANG Data Models", BCP 216, RFC 8407, DOI 10.17487/RFC8407, October 2018, . [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, . [RFC8986] Filsfils, C., Ed., Camarillo, P., Ed., Leddy, J., Voyer, D., Matsushima, S., and Z. Li, "Segment Routing over IPv6 (SRv6) Network Programming", RFC 8986, DOI 10.17487/RFC8986, February 2021, . [RFC9020] Litkowski, S., Qu, Y., Lindem, A., Sarkar, P., and J. Tantsura, "YANG Data Model for Segment Routing", RFC 9020, DOI 10.17487/RFC9020, May 2021, . [RFC9800] Cheng, W., Ed., Filsfils, C., Li, Z., Decraene, B., and F. Clad, Ed., "Compressed SRv6 Segment List Encoding", RFC 9800, DOI 10.17487/RFC9800, June 2025, . 9.2. Informative References [I-D.ietf-spring-sr-service-programming] Clad, F., Xu, X., Filsfils, C., Bernier, D., Li, C., Decraene, B., Ma, S., Yadlapalli, C., Henderickx, W., and S. Salsano, "Service Programming with Segment Routing", Work in Progress, Internet-Draft, draft-ietf-spring-sr- service-programming-11, 23 February 2025, . [RFC8754] Filsfils, C., Ed., Dukes, D., Ed., Previdi, S., Leddy, J., Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header (SRH)", RFC 8754, DOI 10.17487/RFC8754, March 2020, . [RFC9433] Matsushima, S., Ed., Filsfils, C., Kohno, M., Camarillo, P., Ed., and D. Voyer, "Segment Routing over IPv6 for the Mobile User Plane", RFC 9433, DOI 10.17487/RFC9433, July 2023, . Raza, et al. Expires 8 January 2026 [Page 102] Internet-Draft YANG Data Model for SRv6 July 2025 Appendix A. Acknowledgments The authors would like to acknowledge Darren Dukes, Les Ginsberg, Ahmed Bashandy, Rajesh Venkateswaran, and Mike Mallin for their review of some of the contents in this draft. Appendix B. Contributors Zhibo Hu Huawei Technologies Email: huzhibo@huawei.com Sonal Agarwal Individual Katsuhiro Horiba Individual Email: katsuhiro.horiba@gmail.com> Himanshu Shah Ciena Corporation Email: hshah@ciena.com Iftekhar Hussain Individual Email: iftekhar_hussain@yahoo.com Ahmed AbdelSalam Cisco Systems Email: ahabdels@cisco.com Daniel Voyer Individual Email: danvoyerwork@gmail.com Raza, et al. Expires 8 January 2026 [Page 103] Internet-Draft YANG Data Model for SRv6 July 2025 Hani Elmalky Individual Email: helmalky@google.com Authors' Addresses Kamran Raza Cisco Systems Email: skraza@cisco.com Jaganbabu Rajamanickam Cisco Systems Email: jrajaman@cisco.com Satoru Matsushima SoftBank Email: satoru.matsushima@g.softbank.co.jp Pingping Yu Huawei Technologies Email: susana.yu@huawei.com Xufeng Liu Individual Email: xufeng.liu.ietf@gmail.com Raza, et al. Expires 8 January 2026 [Page 104]