LSR Working Group S. Litkowski Internet-Draft Cisco Systems Intended status: Standards Track Y. Qu Expires: 10 January 2024 Futurewei P. Sarkar Individual I. Chen The MITRE Corporation J. Tantsura 9 July 2023 YANG Data Model for IS-IS Segment Routing draft-ietf-isis-sr-yang-16 Abstract This document defines a YANG data module that can be used to configure and manage IS-IS Segment Routing for MPLS data plane. 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 10 January 2024. Copyright Notice Copyright (c) 2023 IETF Trust and the persons identified as the document authors. All rights reserved. Litkowski, et al. Expires 10 January 2024 [Page 1] Internet-Draft isis-sr-yang July 2023 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. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 1.2. Tree Diagrams . . . . . . . . . . . . . . . . . . . . . . 3 2. IS-IS Segment Routing . . . . . . . . . . . . . . . . . . . . 3 2.1. IS-IS Segment Routing configuration . . . . . . . . . . . 6 2.1.1. Segment Routing activation . . . . . . . . . . . . . 6 2.1.2. Advertising mapping server policy . . . . . . . . . . 6 2.1.3. IP Fast reroute . . . . . . . . . . . . . . . . . . . 6 2.2. IS-IS Segment Routing YANG Module . . . . . . . . . . . . 6 3. Security Considerations . . . . . . . . . . . . . . . . . . . 22 4. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 23 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 23 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 23 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 23 7.1. Normative References . . . . . . . . . . . . . . . . . . 23 7.2. Informative References . . . . . . . . . . . . . . . . . 25 Appendix A. A Configuration Example . . . . . . . . . . . . . . 25 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 27 1. Overview YANG [RFC7950] is a data definition language used to define the contents of a conceptual data store that allows networked devices to be managed using NETCONF [RFC6241]. YANG is proving relevant beyond its initial confines, as bindings to other interfaces (e.g., ReST) and encodings other than XML (e.g., JSON) are being defined. Furthermore, YANG data models can be used as the basis for implementation of other interfaces, such as CLI and programmatic APIs. This document defines a YANG data module that can be used to configure and manage IS-IS Segment Routing [RFC8667] for MPLS data plane and it is an augmentation to the IS-IS YANG data model. The YANG modules in this document conform to the Network Management Datastore Architecture (NMDA) [RFC8342]. Litkowski, et al. Expires 10 January 2024 [Page 2] Internet-Draft isis-sr-yang July 2023 1.1. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. 1.2. Tree Diagrams This document uses the graphical representation of data models defined in [RFC8340]. 2. IS-IS Segment Routing This document defines a model for IS-IS Segment Routing feature. It is an augmentation of the IS-IS base model. The IS-IS SR YANG module requires support for the base segment routing module [RFC9020], which defines the global segment routing configuration independent of any specific routing protocol configuration, and support of IS-IS base model [RFC9130] which defines basic IS-IS configuration and state. The figure below describes the overall structure of the isis-sr YANG module: module: ietf-isis-sr augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol/isis:isis: +--rw segment-routing | +--rw enabled? boolean | +--rw bindings | +--rw advertise | | +--rw policies* string | +--rw receive? boolean +--rw protocol-srgb {sr-mpls:protocol-srgb}? +--rw srgb* [lower-bound upper-bound] +--rw lower-bound uint32 +--rw upper-bound uint32 augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol/isis:isis/isis:interfaces /isis:interface: +--rw segment-routing +--rw adjacency-sid +--rw adj-sids* [value] | +--rw value-type? enumeration | +--rw value uint32 Litkowski, et al. Expires 10 January 2024 [Page 3] Internet-Draft isis-sr-yang July 2023 | +--rw protected? boolean +--rw advertise-adj-group-sid* [group-id] | +--rw group-id uint32 +--rw advertise-protection? enumeration augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol/isis:isis/isis:interfaces /isis:interface/isis:fast-reroute: +--rw ti-lfa {ti-lfa}? +--rw enable? boolean augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol/isis:isis/isis:interfaces /isis:interface/isis:fast-reroute/isis:lfa/isis:remote-lfa: +--rw use-segment-routing-path? boolean {remote-lfa-sr}? augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol/isis:isis/isis:interfaces /isis:interface/isis:adjacencies/isis:adjacency: +--ro adjacency-sid* [value] +--ro value uint32 +--ro af? iana-rt-types:address-family +--ro weight? uint8 +--ro protection-requested? boolean augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol/isis:isis/isis:database /isis:levels/isis:lsp/isis:router-capabilities: +--ro sr-capability | +--ro sr-capability | | +--ro sr-capability-bits* identityref | +--ro global-blocks | +--ro global-block* [] | +--ro range-size? uint32 | +--ro sid-sub-tlv | +--ro sid? uint32 +--ro sr-algorithms | +--ro sr-algorithm* uint8 +--ro local-blocks | +--ro local-block* [] | +--ro range-size? uint32 | +--ro sid-sub-tlv | +--ro sid? uint32 +--ro srms-preference +--ro preference? uint8 augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol/isis:isis/isis:database/isis:levels /isis:lsp/isis:extended-is-neighbor/isis:neighbor: +--ro sid-list* [value] +--ro value uint32 +--ro adj-sid-flags | +--ro bits* identityref Litkowski, et al. Expires 10 January 2024 [Page 4] Internet-Draft isis-sr-yang July 2023 +--ro weight? uint8 +--ro neighbor-id? isis:system-id augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol/isis:isis/isis:database /isis:levels/isis:lsp/isis:mt-is-neighbor/isis:neighbor: +--ro sid-list* [value] +--ro value uint32 +--ro adj-sid-flags | +--ro bits* identityref +--ro weight? uint8 +--ro neighbor-id? isis:system-id augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol/isis:isis/isis:database /isis:levels/isis:lsp/isis:extended-ipv4-reachability /isis:prefixes: +--ro sid-list* [value] +--ro value uint32 +--ro perfix-sid-flags | +--ro bits* identityref +--ro algorithm? uint8 augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol/isis:isis/isis:database /isis:levels/isis:lsp/isis:mt-extended-ipv4-reachability /isis:prefixes: +--ro sid-list* [value] +--ro value uint32 +--ro perfix-sid-flags | +--ro bits* identityref +--ro algorithm? uint8 augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol/isis:isis/isis:database /isis:levels/isis:lsp/isis:ipv6-reachability/isis:prefixes: +--ro sid-list* [value] +--ro value uint32 +--ro perfix-sid-flags | +--ro bits* identityref +--ro algorithm? uint8 augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol/isis:isis/isis:database /isis:levels/isis:lsp/isis:mt-ipv6-reachability/isis:prefixes: +--ro sid-list* [value] +--ro value uint32 +--ro perfix-sid-flags | +--ro bits* identityref +--ro algorithm? uint8 augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol/isis:isis/isis:database /isis:levels/isis:lsp: Litkowski, et al. Expires 10 January 2024 [Page 5] Internet-Draft isis-sr-yang July 2023 +--ro segment-routing-bindings* [prefix range] +--ro prefix inet:ip-prefix +--ro range uint16 +--ro sid-binding-flags | +--ro bits* identityref +--ro binding +--ro prefix-sid +--ro sid-list* [value] +--ro value uint32 +--ro perfix-sid-flags | +--ro bits* identityref +--ro algorithm? uint8 2.1. IS-IS Segment Routing configuration 2.1.1. Segment Routing activation Activation of segment-routing IS-IS is done by setting the "enable" leaf to true. This triggers advertisement of segment-routing extensions based on the configuration parameters that have been setup using the base segment routing module. 2.1.2. Advertising mapping server policy The base segment routing module defines mapping server policies. By default, IS-IS will not advertise nor receive any mapping server entry. The IS-IS segment-routing module allows to advertise one or multiple mapping server policies through the "bindings/advertise/ policies" leaf-list. The "bindings/receive" leaf allows to enable the reception of mapping server entries. 2.1.3. IP Fast reroute IS-IS SR model augments the fast-reroute container under interface. It brings the ability to activate TI-LFA (topology independent LFA) and also enhances remote LFA to use segment-routing tunneling instead of LDP. 2.2. IS-IS Segment Routing YANG Module file "ietf-isis-sr@2023-07-09.yang" module ietf-isis-sr { yang-version 1.1; namespace "urn:ietf:params:xml:ns:" + "yang:ietf-isis-sr"; prefix isis-sr; import ietf-routing { Litkowski, et al. Expires 10 January 2024 [Page 6] Internet-Draft isis-sr-yang July 2023 prefix rt; reference "RFC 8349 - A YANG Data Model for Routing Management (NMDA Version)"; } import ietf-inet-types { prefix inet; reference "RFC 6991 - Common YANG Data Types"; } import ietf-segment-routing-common { prefix sr-cmn; reference "RFC 9020 - YANG Data Model for Segment Routing"; } import ietf-segment-routing-mpls { prefix sr-mpls; reference "RFC 9020 - YANG Data Model for Segment Routing"; } import ietf-isis { prefix isis; reference "RFC 9130 - YANG Data Model for IS-IS Protocol"; } import iana-routing-types { prefix iana-rt-types; reference "RFC 8294 - Common YANG Data Types for the Routing Area"; } organization "IETF LSR - LSR Working Group"; contact "WG List: Author: Stephane Litkowski Author: Acee Lindem Author: Yingzhen Qu Author: Pushpasis Sarkar Litkowski, et al. Expires 10 January 2024 [Page 7] Internet-Draft isis-sr-yang July 2023 Author: Ing-Wher Chen Author: Jeff Tantsura "; description "The YANG module defines a generic configuration model for Segment routing ISIS extensions common across all of the vendor implementations. This YANG model conforms to the Network Management Datastore Architecture (NMDA) as described in RFC 8342. Copyright (c) 2023 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Revised BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX (https://www.rfc-editor.org/info/rfcXXXX); see the RFC itself for full legal notices. The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'NOT RECOMMENDED', 'MAY', and 'OPTIONAL' in this document are to be interpreted as described in BCP 14 (RFC 2119) (RFC 8174) when, and only when, they appear in all capitals, as shown here. This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices."; reference "RFC XXXX"; revision 2023-07-09 { description "Initial revision."; reference "RFC XXXX"; } /* Identities */ Litkowski, et al. Expires 10 January 2024 [Page 8] Internet-Draft isis-sr-yang July 2023 identity sr-capability { description "Base identity for ISIS SR-Capabilities sub-TLV flgs"; } identity mpls-ipv4 { base sr-capability; description "If set, then the router is capable of processing SR MPLS encapsulated IPv4 packets on all interfaces."; } identity mpls-ipv6 { base sr-capability; description "If set, then the router is capable of processing SR MPLS encapsulated IPv6 packets on all interfaces."; } identity prefix-sid-bit { description "Base identity for prefix sid sub-tlv bits."; } identity r-bit { base prefix-sid-bit; description "Re-advertisement Flag."; } identity n-bit { base prefix-sid-bit; description "Node-SID Flag."; } identity p-bit { base prefix-sid-bit; description "No-PHP (No Penultimate Hop-Popping) Flag."; } identity e-bit { base prefix-sid-bit; description "Explicit NULL Flag."; Litkowski, et al. Expires 10 January 2024 [Page 9] Internet-Draft isis-sr-yang July 2023 } identity v-bit { base prefix-sid-bit; description "Value Flag."; } identity l-bit { base prefix-sid-bit; description "Local Flag."; } identity adj-sid-bit { description "Base identity for adj sid sub-tlv bits."; } identity f-bit { base adj-sid-bit; description "Address-Family flag."; } identity b-bit { base adj-sid-bit; description "Backup flag."; } identity vi-bit { base adj-sid-bit; description "Value/Index flag."; } identity lo-bit { base adj-sid-bit; description "Local flag."; } identity s-bit { base adj-sid-bit; description "Group flag."; } Litkowski, et al. Expires 10 January 2024 [Page 10] Internet-Draft isis-sr-yang July 2023 identity pe-bit { base adj-sid-bit; description "Persistent flag."; } identity sid-binding-bit { description "Base identity for sid binding tlv bits."; } identity af-bit { base sid-binding-bit; description "Address-Family flag."; } identity m-bit { base sid-binding-bit; description "Mirror Context flag."; } identity sf-bit { base sid-binding-bit; description "S flag. If set, the binding label tlv should be flooded across the entire routing domain."; } identity d-bit { base sid-binding-bit; description "Leaking flag."; } identity a-bit { base sid-binding-bit; description "Attached flag."; } /* Features */ feature remote-lfa-sr { description "Enhance rLFA to use SR path."; } Litkowski, et al. Expires 10 January 2024 [Page 11] Internet-Draft isis-sr-yang July 2023 feature ti-lfa { description "Enhance IPFRR with ti-lfa support"; } /* Groupings */ grouping sid-sub-tlv { description "SID/Label sub-TLV grouping."; container sid-sub-tlv { description "Used to advertise the SID/Label associated with a prefix or adjacency."; leaf sid { type uint32; description "Segment Identifier (SID) - A 20 bit label or 32 bit SID."; } } } grouping sr-capability { description "SR capability grouping."; container sr-capability { description "Segment Routing capability."; container sr-capability { leaf-list sr-capability-bits { type identityref { base sr-capability; } description "SR Capability sub-tlv flags list."; } description "SR Capability Flags."; } container global-blocks { description "Segment Routing Global Blocks."; list global-block { description "Segment Routing Global Block."; leaf range-size { Litkowski, et al. Expires 10 January 2024 [Page 12] Internet-Draft isis-sr-yang July 2023 type uint32; description "The SID range."; } uses sid-sub-tlv; } } } } grouping sr-algorithm { description "SR algorithm grouping."; container sr-algorithms { description "All SR algorithms."; leaf-list sr-algorithm { type uint8; description "The Segment Routing (SR) algorithms that the router is currently using."; } } } grouping srlb { description "SR Local Block grouping."; container local-blocks { description "List of SRLBs."; list local-block { description "Segment Routing Local Block."; leaf range-size { type uint32; description "The SID range."; } uses sid-sub-tlv; } } } grouping srms-preference { description "The SRMS preference TLV is used to advertise a preference associated with the node that acts Litkowski, et al. Expires 10 January 2024 [Page 13] Internet-Draft isis-sr-yang July 2023 as an SR Mapping Server."; container srms-preference { description "SRMS Preference TLV."; leaf preference { type uint8 { range "0 .. 255"; } description "SRMS preference TLV, value from 0 to 255."; } } } grouping adjacency-state { description "This group will extend adjacency state."; list adjacency-sid { key "value"; config false; leaf value { type uint32; description "Value of the Adj-SID."; } leaf af { type iana-rt-types:address-family; description "Address-family associated with the segment ID"; } leaf weight { type uint8; description "Weight associated with the adjacency SID."; } leaf protection-requested { type boolean; description "Describe if the adjacency SID must be protected."; } description "List of adjacency Segment IDs."; } } Litkowski, et al. Expires 10 January 2024 [Page 14] Internet-Draft isis-sr-yang July 2023 grouping prefix-segment-id { description "This group defines segment routing extensions for prefixes."; list sid-list { key "value"; leaf value { type uint32; description "Value of the prefix-SID."; } container perfix-sid-flags { leaf-list bits { type identityref { base prefix-sid-bit; } description "Prefix SID Sub-TLV flag bits list."; } description "Describes flags associated with the segment ID."; } leaf algorithm { type uint8; description "Algorithm to be used for path computation."; } description "List of segments."; } } grouping adjacency-segment-id { description "This group defines segment routing extensions for adjacencies."; list sid-list { key "value"; leaf value { type uint32; description "Value of the Adj-SID."; } container adj-sid-flags { leaf-list bits { type identityref { base adj-sid-bit; Litkowski, et al. Expires 10 January 2024 [Page 15] Internet-Draft isis-sr-yang July 2023 } description "Adj sid sub-tlv flags list."; } description "Adj-sid sub-tlv flags."; } leaf weight { type uint8; description "The value represents the weight of the Adj-SID for the purpose of load balancing."; } leaf neighbor-id { type isis:system-id; description "Describes the system ID of the neighbor associated with the SID value. This is only used on LAN adjacencies."; } description "List of segments."; } } grouping segment-routing-binding-tlv { list segment-routing-bindings { key "prefix range"; leaf prefix { type inet:ip-prefix; description "The prefix represents the Forwarding Equivalence Class at the tail end of the advertised path."; } leaf range { type uint16; description "Describes number of elements to assign a binding to."; } container sid-binding-flags { leaf-list bits { type identityref { base sid-binding-bit; } description "SID Binding TLV flag bits list."; } Litkowski, et al. Expires 10 January 2024 [Page 16] Internet-Draft isis-sr-yang July 2023 description "Binding flags."; } container binding { container prefix-sid { uses prefix-segment-id; description "Binding prefix SID to the range."; } description "Bindings associated with the range."; } description "This container describes list of SID/Label bindings. ISIS reference is TLV 149."; } description "Defines binding TLV for database."; } /* Cfg */ augment "/rt:routing/" + "rt:control-plane-protocols/rt:control-plane-protocol" + "/isis:isis" { when "derived-from-or-self(../rt:type, 'isis:isis')" { description "This augment ISIS routing protocol when used"; } description "This augments ISIS protocol configuration with segment routing."; uses sr-mpls:sr-control-plane; container protocol-srgb { if-feature "sr-mpls:protocol-srgb"; uses sr-cmn:srgb; description "Per-protocol SRGB."; } } augment "/rt:routing/" + "rt:control-plane-protocols/rt:control-plane-protocol" + "/isis:isis/isis:interfaces/isis:interface" { when "derived-from-or-self(../../../rt:type, 'isis:isis')" { description "This augment ISIS routing protocol when used"; } Litkowski, et al. Expires 10 January 2024 [Page 17] Internet-Draft isis-sr-yang July 2023 description "This augments ISIS protocol configuration with segment routing."; uses sr-mpls:igp-interface; } augment "/rt:routing/" + "rt:control-plane-protocols/rt:control-plane-protocol" + "/isis:isis/isis:interfaces/isis:interface" + "/isis:fast-reroute" { when "derived-from-or-self(../../../../rt:type, 'isis:isis')" { description "This augment ISIS routing protocol when used"; } description "This augments ISIS IP FRR with TILFA."; container ti-lfa { if-feature "ti-lfa"; leaf enable { type boolean; default false; description "Enables TI-LFA computation."; } description "TI-LFA configuration."; } } augment "/rt:routing/" + "rt:control-plane-protocols/rt:control-plane-protocol" + "/isis:isis/isis:interfaces/isis:interface" + "/isis:fast-reroute/isis:lfa/isis:remote-lfa" { when "derived-from-or-self(../../../../../../rt:type," + "'isis:isis')" { description "This augment ISIS routing protocol when used"; } description "This augments ISIS remoteLFA config with use of segment-routing path."; leaf use-segment-routing-path { if-feature "remote-lfa-sr"; type boolean; default false; description "Force remote LFA to use segment routing path instead of LDP path. The value of this leaf is in effect only when Litkowski, et al. Expires 10 January 2024 [Page 18] Internet-Draft isis-sr-yang July 2023 remote-lfa is enabled."; } } /* Operational states */ augment "/rt:routing/" + "rt:control-plane-protocols/rt:control-plane-protocol" + "/isis:isis/isis:interfaces/isis:interface" + "/isis:adjacencies/isis:adjacency" { when "derived-from-or-self(../../../../../rt:type, 'isis:isis')" { description "This augment ISIS routing protocol when used"; } description "This augments ISIS protocol configuration with segment routing."; uses adjacency-state; } augment "/rt:routing/" + "rt:control-plane-protocols/rt:control-plane-protocol" + "/isis:isis/isis:database/isis:levels/isis:lsp" + "/isis:router-capabilities" { when "derived-from-or-self(../../../../../rt:type, 'isis:isis')" { description "This augment ISIS routing protocol when used"; } description "This augments ISIS protocol LSDB router capability."; uses sr-capability; uses sr-algorithm; uses srlb; uses srms-preference; } augment "/rt:routing/" + "rt:control-plane-protocols/rt:control-plane-protocol" + "/isis:isis/isis:database/isis:levels/isis:lsp" + "/isis:extended-is-neighbor/isis:neighbor" { when "derived-from-or-self(../../../../../../rt:type," + "'isis:isis')" { description "This augment ISIS routing protocol when used"; } description "This augments ISIS protocol LSDB neighbor."; uses adjacency-segment-id; Litkowski, et al. Expires 10 January 2024 [Page 19] Internet-Draft isis-sr-yang July 2023 } augment "/rt:routing/" + "rt:control-plane-protocols/rt:control-plane-protocol" + "/isis:isis/isis:database/isis:levels/isis:lsp" + "/isis:mt-is-neighbor/isis:neighbor" { when "derived-from-or-self(../../../../../../rt:type," + "'isis:isis')" { description "This augment ISIS routing protocol when used"; } description "This augments ISIS protocol LSDB neighbor."; uses adjacency-segment-id; } augment "/rt:routing/" + "rt:control-plane-protocols/rt:control-plane-protocol" + "/isis:isis/isis:database/isis:levels/isis:lsp" + "/isis:extended-ipv4-reachability/isis:prefixes" { when "derived-from-or-self(../../../../../../rt:type," + "'isis:isis')" { description "This augment ISIS routing protocol when used"; } description "This augments ISIS protocol LSDB prefix."; uses prefix-segment-id; } augment "/rt:routing/" + "rt:control-plane-protocols/rt:control-plane-protocol" + "/isis:isis/isis:database/isis:levels/isis:lsp" + "/isis:mt-extended-ipv4-reachability/isis:prefixes" { when "derived-from-or-self(../../../../../../rt:type," + "'isis:isis')" { description "This augment ISIS routing protocol when used"; } description "This augments ISIS protocol LSDB prefix."; uses prefix-segment-id; } augment "/rt:routing/" + "rt:control-plane-protocols/rt:control-plane-protocol" + "/isis:isis/isis:database/isis:levels/isis:lsp" + "/isis:ipv6-reachability/isis:prefixes" { Litkowski, et al. Expires 10 January 2024 [Page 20] Internet-Draft isis-sr-yang July 2023 when "derived-from-or-self(../../../../../../rt:type," + "'isis:isis')" { description "This augment ISIS routing protocol when used"; } description "This augments ISIS protocol LSDB prefix."; uses prefix-segment-id; } augment "/rt:routing/" + "rt:control-plane-protocols/rt:control-plane-protocol" + "/isis:isis/isis:database/isis:levels/isis:lsp" + "/isis:mt-ipv6-reachability/isis:prefixes" { when "derived-from-or-self(../../../../../../rt:type," + "'isis:isis')" { description "This augment ISIS routing protocol when used"; } description "This augments ISIS protocol LSDB prefix."; uses prefix-segment-id; } augment "/rt:routing/" + "rt:control-plane-protocols/rt:control-plane-protocol" + "/isis:isis/isis:database/isis:levels/isis:lsp" { when "derived-from-or-self(../../../../rt:type," + "'isis:isis')" { description "This augment ISIS routing protocol when used"; } description "This augments ISIS protocol LSDB."; uses segment-routing-binding-tlv; } /* Notifications */ } Litkowski, et al. Expires 10 January 2024 [Page 21] Internet-Draft isis-sr-yang July 2023 3. 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]. The NETCONF Access Control Model (NACM) [RFC8341] provides the means to restrict access for particular NETCONF or RESTCONF users to a pre- configured 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. These are the subtrees and data nodes and their sensitivity/vulnerability: /isis:isis/segment-routing /isis:isis/protocol-srgb /isis:isis/isis:interfaces/isis:interface/segment-routing /isis:isis/isis:interfaces/isis:interface/isis:fast-reroute/ti-lfa Some of the readable data nodes in the modules 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. /isis:router-capabilities/sr-capability /isis:router-capabilities/sr-algorithms /isis:router-capabilities/local-blocks /isis:router-capabilities/srms-preference /isis:router-capabilities/node-msd-tlv And the augmentations to the ISIS link state database. Litkowski, et al. Expires 10 January 2024 [Page 22] Internet-Draft isis-sr-yang July 2023 Unauthorized access to any data node of these subtrees can disclose the operational state information of IS-IS protocol on this device. 4. Contributors Authors would like to thank Derek Yeung, Acee Lindem, Yi Yang for their major contributions to the draft. 5. Acknowledgements MITRE has approved this document for Public Release, Distribution Unlimited, with Public Release Case Number 19-3033. 6. IANA Considerations The IANA is requested to assign one new URI from the IETF XML registry ([RFC3688]). Authors are suggesting the following URI: URI: urn:ietf:params:xml:ns:yang:ietf-isis-sr Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace This document also requests one new YANG module name in the YANG Module Names registry ([RFC6020]) with the following suggestion : name: ietf-isis-sr namespace: urn:ietf:params:xml:ns:yang:ietf-isis-sr prefix: isis-sr reference: RFC XXXX 7. References 7.1. 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, . Litkowski, et al. Expires 10 January 2024 [Page 23] Internet-Draft isis-sr-yang July 2023 [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, . [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . [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, . [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, . [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, . [RFC8667] Previdi, S., Ed., Ginsberg, L., Ed., Filsfils, C., Bashandy, A., Gredler, H., and B. Decraene, "IS-IS Extensions for Segment Routing", RFC 8667, DOI 10.17487/RFC8667, December 2019, . [RFC9020] Litkowski, S., Qu, Y., Sarkar, P., and J. Tantsura, "YANG Data Model for Segment Routing", RFC 9020, May 2021, . Litkowski, et al. Expires 10 January 2024 [Page 24] Internet-Draft isis-sr-yang July 2023 [RFC9130] Litkowski, S., Yeung, D., Lindem, A., Zhang, J., and L. Lhotka, "YANG Data Model for IS-IS Protocol", Work in Progress, Internet-Draft, draft-ietf-isis-yang-isis-cfg- 42, 15 October 2019, . 7.2. Informative References [RFC8792] Watsen, K., Auerswald, E., Farrel, A., and Q. Wu, "Handling Long Lines in Content of Internet-Drafts and RFCs", RFC 8792, DOI 10.17487/RFC8792, June 2020, . Appendix A. A Configuration Example The following is an XML example using the ISIS SR YANG module defined in this document. Note: '\' line wrapping per [RFC8792]. Litkowski, et al. Expires 10 January 2024 [Page 25] Internet-Draft isis-sr-yang July 2023 1.1.1.1 \ isis:isis isis 1111.2222.3333 38888 true 4000 5000 The following is the same example using JSON format. Litkowski, et al. Expires 10 January 2024 [Page 26] Internet-Draft isis-sr-yang July 2023 { "routing": { "router-id": "1.1.1.1", "control-plane-protocols": { "control-plane-protocol": { "type": "isis:isis", "name": "isis", "isis": { "system-id": "1111.2222.3333", "interfaces": { "interface": { "name": "", "segment-routing": { "adjacency-sid": { "adj-sids": { "value": 38888 } } } } }, "segment-routing": { "enabled": true }, "protocol-srgb": { "srgb": { "lower-bound": 4000, "upper-bound": 5000 } } } } } } } Authors' Addresses Stephane Litkowski Cisco Systems Email: slitkows.ietf@gmail.com Yingzhen Qu Futurewei Email: yingzhen.qu@futurewei.com Litkowski, et al. Expires 10 January 2024 [Page 27] Internet-Draft isis-sr-yang July 2023 Pushpasis Sarkar Individual Email: pushpasis.ietf@gmail.com Ing-Wher Chen The MITRE Corporation Email: ingwherchen@mitre.org Jeff Tantsura Email: jefftant.ietf@gmail.com Litkowski, et al. Expires 10 January 2024 [Page 28]