]> A YANG Data Model for IS-IS Segment Routing over the MPLS Data Plane Cisco Systems
slitkows.ietf@gmail.com
Futurewei Technologies
yingzhen.ietf@gmail.com
LabN Consulting, L.L.C.
acee.ietf@gmail.com
The MITRE Corporation
ingwherchen@mitre.org
Nvidia
jefftant.ietf@gmail.com
LSR Working Group This document defines a YANG data model that can be used to manage IS-IS Extensions for Segment Routing over the MPLS data plane.
Overview This document defines a device YANG data model that can be used to manage IS-IS Extensions for Segment Routing over the MPLS data plane. It is an augmentation to the IS-IS YANG data model . The YANG data model in this document conforms to the Network Management Datastore Architecture (NMDA) .
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 when, and only when, they appear in all capitals, as shown here.
Tree Diagrams This document uses the graphical representation of data model defined in .
Design of the IS-IS MPLS Segment Routing Module This document defines a YANG data model for IS-IS Extensions for Segment Routing over the MPLS data plane. It is an augmentation of the IS-IS base model. The IS-IS SR MPLS YANG module requires support for the base segment routing module , which defines the global segment routing management independent of any specific routing protocol configuration, and support of IS-IS base model which defines basic IS-IS configuration and state. The ietf-isis-sr-mpls data module defines both the data nodes to configure IS-IS segment routing MPLS extensions and the additions to the IS-IS Link State Protocol Data Units (LSPs) necessary to support MPLS segment routing.
Segment Routing Activation Activation of IS-IS SR MPLS is done by setting the "enable" leaf to true. This triggers advertisement of SR MPLS extensions based on the configuration parameters that have been set up using the base segment routing module.
Advertising Mapping Server Policy The base segment routing module defines mapping server policies. By default, IS-IS will not advertise or process any mapping server entry. The IS-IS SR MPLS module allows the advertisement of one or multiple mapping server policies through the "bindings/advertise/policies" leaf-list. The "bindings/receive" leaf controls the reception and process of mapping server entries.
IP Fast Reroute IS-IS SR MPLS 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.
IS-IS MPLS Segment Routing over MPLS YANG Module , , , , , , , and are referenced in the YANG module.
file "ietf-isis-sr-mpls@2025-04-22.yang" module ietf-isis-sr-mpls { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-isis-sr-mpls"; prefix isis-sr-mpls; import ietf-routing { 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"; } import ietf-routing-types { prefix rt-types; reference "RFC 8294: Common YANG Data Types for the Routing Area"; } organization "IETF LSR - Link State Routing Working Group"; contact "WG Web: WG List: Author: Stephane Litkowski Author: Yingzhen Qu Author: Acee Lindem Author: Ing-Wher Chen Author: Jeff Tantsura "; description "The YANG module defines the generic configuration and operational state for Segment Routing ISIS extensions for the MPLS data plane. This YANG model conforms to the Network Management Datastore Architecture (NMDA) as described in RFC 8342. Copyright (c) 2025 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."; // RFC Ed.: Replace XXXX with actual RFC number and remove // this note revision 2025-04-22 { description "Initial revision."; reference "RFC XXXX: A YANG Data Model for IS-IS Segment Routing over the MPLS Data Plane"; } // RFC Ed.: Replace XXXX with actual RFC number. // Also, replace '2025-04-22' with the module publication date // in the format (YYYY-MM-DD) and remove this note. /* Features */ feature remote-lfa-sr { description "Enhance rLFA to use SR path."; reference "RFC 8102: Remote-LFA Node Protection and Manageability"; } feature ti-lfa { description "Topology-Independent Loop-Free Alternate (TI-LFA) computation using segment routing."; reference "draft-ietf-rtgwg-segment-routing-ti-lfa - Topology-Independent Fast Reroute using Segment Routing"; } /* Identities */ identity sr-capability { description "Base identity for ISIS SR-Capabilities sub-TLV flags"; reference "RFC 8667: IS-IS Extensions for Segment Routing"; } 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-flag { description "Base identity for prefix SID sub-TLV flags."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.1"; } identity r-flag { base prefix-sid-flag; description "Re-advertisement Flag."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.1"; } identity n-flag { base prefix-sid-flag; description "Node-SID Flag."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.1"; } identity p-flag { base prefix-sid-flag; description "No-PHP (No Penultimate Hop-Popping) Flag."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.1"; } identity e-flag { base prefix-sid-flag; description "Explicit NULL Flag."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.1"; } identity v-flag { base prefix-sid-flag; description "Value Flag."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.1"; } identity l-flag { base prefix-sid-flag; description "Local Flag."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.1"; } identity adj-sid-flag { description "Base identity for Adj-SID sub-TLV flags."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.2"; } identity f-flag { base adj-sid-flag; description "Address-Family flag."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.2"; } identity b-flag { base adj-sid-flag; description "Backup flag."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.2"; } identity vi-flag { base adj-sid-flag; description "Value/Index flag - corresponds to V-Flag in reference."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.2"; } identity lg-flag { base adj-sid-flag; description "Local/Global flag - corresponds to L-Flag in reference."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.2"; } identity s-flag { base adj-sid-flag; description "Set flag - corresponds to S-Flag in reference.."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.2"; } identity pe-flag { base adj-sid-flag; description "Persistent flag - corresponds to P-Flag in reference."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.2"; } identity sid-binding-flag { description "Base identity for sid binding tlv flags."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.4"; } identity af-flag { base sid-binding-flag; description "Address-Family flag - corresponds to F-Flag in reference."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.4"; } identity m-flag { base sid-binding-flag; description "Mirror Context flag."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.4"; } identity sf-flag { base sid-binding-flag; description "S flag. If set, the binding label TLV should be flooded across the entire routing domain - corresponds to S-Flag in reference."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.4"; } identity d-flag { base sid-binding-flag; description "Leaking flag."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.4"; } identity a-flag { base sid-binding-flag; description "Attached flag."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.4"; } /* Groupings */ grouping sid-tlv-encoding { description "SID TLV Encoding - 20-bit label or 32-bit SID index whose interpretation is dependent on the TLV length (3 for an MPLS label or 4 for a 32-bit value) or the TLV V-Flag and L-Flag settings: If the V-Flag is set to 0 and L-Flag is set to 0: The SID/Index/Label field is a 4-octet index defining the offset in the SID/Label space advertised by this router. If V-Flag is set to 1 and L-Flag is set to 1: The ID/Index/Label field is a 3-octet local label where the 20 rightmost bits are used for encoding the label value."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.1.1.1"; choice sid { case sid-label { leaf label-value { type uint32 { range "0 .. 1048575"; } description "A 20-bit MPLS Label"; } } case sid-index { leaf index-value { type uint32; description "Index into a label space advertised by this router."; } } description "Choice of either a 20-bit MPLS label or 32-bit index into an advertised label space."; } } grouping sid-sub-tlv { description "SID/Label sub-TLV grouping."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.4"; container sid-sub-tlv { description "Used to advertise the SID/Label associated with a prefix or adjacency."; leaf length { type uint8; description "Length of the SID value. YANG model specification is necessary since it dictates the semantics of the SID."; } uses sid-tlv-encoding; } } grouping sr-capability { description "SR capability grouping."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 3.1"; container sr-capability { description "SR Capability Flags."; leaf-list sr-capability-flag { type identityref { base sr-capability; } description "SR Capability sub-TLV flags."; } container global-blocks { description "Segment Routing Global Blocks."; list global-block { description "Segment Routing Global Block."; leaf range-size { type rt-types:uint24; description "The SID range."; } uses sid-sub-tlv; } } } } grouping sr-algorithm { description "SR algorithm grouping."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 3.2"; container sr-algorithms { description "All SR algorithms."; leaf-list sr-algorithm { type identityref { base sr-cmn:prefix-sid-algorithm; } description "The Segment Routing (SR) algorithms that the router is currently using."; } } } grouping srlb { description "SR Local Block grouping."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 3.3"; container local-blocks { description "List of SRLBs."; list local-block { description "Segment Routing Local Block."; leaf range-size { type rt-types:uint24; 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 as an SR Mapping Server."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 3.4"; container srms-preference { description "SRMS Preference TLV."; leaf preference { type uint8; description "SRMS preference TLV, value from 0 to 255 with 255 being the most preferred."; } } } grouping adjacency-state { description "This grouping extends adjacency state."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.2"; list adjacency-sid { config false; description "List of adjacency Segment IDs."; leaf value { type uint32; description "Value of the Adj-SID."; } leaf address-family { 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."; } } } grouping prefix-sid-sub-tlv { description "This grouping defines segment routing prefix segment identifier (prefix-sid) sub-tlv."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.1"; container prefix-sid-sub-tlvs { description "PrefixSID sub-tlvs."; list prefix-sid-sub-tlv { description "List of prefix-sid sub-tlvs."; container prefix-sid-flags { description "Describes flags associated with the segment ID."; leaf-list flag { type identityref { base prefix-sid-flag; } description "Prefix SID sub-TLV flags."; } } leaf algorithm { type identityref { base sr-cmn:prefix-sid-algorithm; } description "Algorithm to be used for path computation."; } uses sid-tlv-encoding; } } } grouping adjacency-segment-id { description "This grouping defines segment routing extensions for adjacencies."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.2"; container adj-sid-sub-tlvs { description "Adj-SID optional sub-TLVs."; list adj-sid-sub-tlv { description "List of segments."; container adj-sid-flags { description "Adj-SID sub-TLV flags."; leaf-list flag { type identityref { base adj-sid-flag; } description "Adj-SID sub-TLV flags list."; } } 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."; } uses sid-tlv-encoding; } } } grouping sid-binding-tlv { description "SID/Label binding TLV, type 149."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.4"; 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 "Provides the ability to specify a range of addresses and their associated prefix-sids."; } container sid-binding-flags { description "Binding TLV flags."; leaf-list flag { type identityref { base sid-binding-flag; } description "SID Binding TLV flags."; } } list prefix-sid-sub-tlvs { description "List of prefix-sid sub-tlvs."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.4.4"; uses prefix-sid-sub-tlv; } list sid-sub-tlv { description "List of prefix-sid sub-tlvs."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.4.5"; uses sid-sub-tlv; } uses isis:unknown-tlvs; } /* Configuration */ augment "/rt:routing/" + "rt:control-plane-protocols/rt:control-plane-protocol" + "/isis:isis" { when "derived-from-or-self(../rt:type, 'isis:isis')" { description "This augments ISIS routing protocol when used"; } description "This augments ISIS protocol configuration with segment routing for the MPLS data plane."; uses sr-mpls:sr-control-plane; container protocol-srgb { if-feature "sr-mpls:protocol-srgb"; description "Per-protocol Segment Routing Global Block (SRGB)."; reference "RFC 8402: Segment Routing Architecture, Section 2"; uses sr-cmn: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 augments ISIS routing protocol when used"; } description "This augments ISIS protocol configuration with segment routing."; uses sr-mpls:igp-interface { augment "segment-routing/adjacency-sid/adj-sids" { when "../../../isis:interface-type = 'broadcast'" { description "This augments broadcast interface."; } description "This augments LAN interface adj-sid with system-id."; leaf neighbor-system-id { type isis:system-id; mandatory true; description "Neighbor system ID."; } } } } augment "/rt:routing/" + "rt:control-plane-protocols/rt:control-plane-protocol" + "/isis:isis/isis:interfaces/isis:interface" + "/isis:fast-reroute/isis:lfa" { when "derived-from-or-self(../../../../../rt:type," + "'isis:isis')" { description "This augments ISIS routing protocol when used"; } description "This augments ISIS interface IP FRR with TILFA."; container ti-lfa { if-feature "ti-lfa"; description "Topology Independent Loop Free Alternate (TI-LFA) support."; leaf enabled { type boolean; default "false"; description "Enables TI-LFA computation."; } container selection-tie-breakers { description "Configure path selection tie-breakers and their respective priorities for the TI-LFA computation."; container node-protection { presence "Presence of container enables the node protection tie-breaker"; description "Enable node protection as a TI-LFA path selection tie-breaker. A path providing node protection will be selected over one that doesn't provide node protection."; leaf priority { type uint8; default "128"; description "Priority for node protection tie-breaker with a lower priority being more preferred."; } } container srlg-disjoint { presence "Presence of container enables the SRLG disjoint tie-breaker"; description "Enable SRLG (Shared Resource Link Group) disjoint as a TI-LFA path selection tie-breaker. A path providing node a disjoint path for SRLG links from the primary path will be selected over one that doesn't provide an SRLG disjoint path."; leaf priority { type uint8; default "128"; description "Priority for SRLG disjoint tie-breaker with a lower priority being more preferred."; } } } } } augment "/rt:routing/" + "rt:control-plane-protocols/rt:control-plane-protocol" + "/isis:isis/isis:interfaces/isis:interface" + "/isis:fast-reroute/isis:lfa/isis:level-1" { when "derived-from-or-self(../../../../../../rt:type," + "'isis:isis')" { description "This augments ISIS routing protocol when used"; } description "This augments ISIS interface level-1 IP FRR with TILFA."; container ti-lfa { if-feature "ti-lfa"; description "TI-LFA configuration."; leaf enabled { type boolean; default "false"; description "Enables TI-LFA computation."; } } } augment "/rt:routing/" + "rt:control-plane-protocols/rt:control-plane-protocol" + "/isis:isis/isis:interfaces/isis:interface" + "/isis:fast-reroute/isis:lfa/isis:level-2" { when "derived-from-or-self(../../../../../../rt:type," + "'isis:isis')" { description "This augments ISIS routing protocol when used"; } description "This augments ISIS IP interface level-2 FRR with TILFA."; container ti-lfa { if-feature "ti-lfa"; description "TI-LFA configuration."; leaf enabled { type boolean; default "false"; description "Enables TI-LFA computation."; } } } 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 augments 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 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 augments 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/isis:router-capability" { when "derived-from-or-self(../../../../../../rt:type," + "'isis:isis')" { description "This augments 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/isis:instances" + "/isis:instance" { when "derived-from-or-self(../../../../../../../../rt:type," + "'isis:isis')" { description "This augments 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:mt-is-neighbor/isis:neighbor/isis:instances" + "/isis:instance" { when "derived-from-or-self(../../../../../../../../rt:type," + "'isis:isis')" { description "This augments 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 augments ISIS routing protocol when used"; } description "This augments ISIS protocol LSDB prefix."; uses prefix-sid-sub-tlv; } 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 augments ISIS routing protocol when used"; } description "This augments ISIS protocol LSDB prefix."; uses prefix-sid-sub-tlv; } augment "/rt:routing/" + "rt:control-plane-protocols/rt:control-plane-protocol" + "/isis:isis/isis:database/isis:levels/isis:lsp" + "/isis:ipv6-reachability/isis:prefixes" { when "derived-from-or-self(../../../../../../rt:type," + "'isis:isis')" { description "This augments ISIS routing protocol when used"; } description "This augments ISIS protocol LSDB prefix."; uses prefix-sid-sub-tlv; } 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 augments ISIS routing protocol when used"; } description "This augments ISIS protocol LSDB prefix."; uses prefix-sid-sub-tlv; } 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 augments ISIS routing protocol when used"; } description "This augments ISIS protocol LSDB."; container sid-binding-tlvs { description "List of sid/label binding TLVs."; list sid-binding-tlv { key "prefix"; description "Sid/label binding TLV, type 149."; uses sid-binding-tlv; } } container mt-sid-binding-tlvs { description "List of multi-topology sid/label binding TLVs."; list mt-sid-binding-tlv { key "prefix mt-id"; description "Multi-Topology SID/Label binding TLV, type 150."; reference "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.5"; uses sid-binding-tlv; leaf mt-id { type uint16; description "A 12-bit field containing the non-zero ID of the topology."; } } } } } ]]>
Security Considerations The ietf-isis-sr-mpls YANG module defines a data model that is designed to be accessed via YANG-based management protocols, such as NETCONF and RESTCONF . These YANG-based management protocols (1) have to use a secure transport layer (e.g., SSH , TLS , and QUIC ) and (2) have to use mutual authentication. The Network Configuration Access Control Model (NACM) 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). All writable data nodes are likely to be reasonably sensitive or vulnerable in some network environments. Write operations (e.g., edit-config) and delete operations to these data nodes without proper protection or authentication can have a negative effect on network operations. The following subtrees and data nodes have particular sensitivities/vulnerabilities:
  • /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
The ability to disable or enable IS-IS Segment Routing support and/or change Segment Routing configurations can result in a Denial-of-Service (DoS) attack, as this may cause traffic to be dropped or misrouted. Please refer to Section 5 of for more information on Segment Routing extensions. 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
  • And the augmentations to the ISIS link state database.
Unauthorized access to any data node of these subtrees can disclose the operational state information of IS-IS protocol on a device.
Acknowledgements The authors would like to thank Pushpasis Sarkar, Derek Yeung,Yi Yang for their major contributions to the draft. Also thank Reshad Rahman, Tom Petch, and Renato Westphal for their thorough reviews and helpful comments. The authors wish to thank Mohamed Boucadair and Ketan Talaulikar for extensive AD reviews for the IESG Telechat. Thanks to Eric Vyncke and Mahesh Jethanandani for review comments. Author affiliation with The MITRE Corporation is provided for identification purposes only, and is not intended to convey or imply MITRE's concurrence with, or support for, the positions, opinions or viewpoints expressed. MITRE has agreed to this document for Public Release, Distribution Unlimited, with Public Release Case Number 19-3033. This approval allows the MITRE employee to release contributions externally and does not assert authority to publish.
IANA Considerations The IANA is requested to assign one new URI from the IETF XML registry (): This document also requests one new YANG module name in the YANG Module Names registry ():
References Normative References Informative References
A Configuration Example The following is an XML example using the ISIS SR MPLS YANG module defined in this document. Note: '\' line wrapping per . eth0 up up 1 2024-10-27T14:30:00Z 1.1.1.1 \ isis:isis isis 1111.2222.3333 49.0001.0000.0000.0001 eth0 38888 4444.5555.6666 true 4000 5000 ]]> The following is the same example using JSON format.
IS-IS MPLS Segment Routing Module Tree The figure below describes the overall structure of the ietf-isis-sr-mpls YANG module: /rt:routing/sr:segment-routing | | /sr-mpls:sr-mpls/bindings | | /mapping-server/policy/name | +--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 | +--rw protected? boolean | +--rw weight? uint8 | +--rw neighbor-system-id isis:system-id +--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/isis:lfa: +--rw ti-lfa {ti-lfa}? +--rw enabled? boolean +--rw selection-tie-breakers +--rw node-protection! | +--rw priority? uint8 +--rw srlg-disjoint! +--rw priority? uint8 augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol/isis:isis/isis:interfaces /isis:interface/isis:fast-reroute/isis:lfa/isis:level-1: +--rw ti-lfa {ti-lfa}? +--rw enabled? boolean augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol/isis:isis/isis:interfaces /isis:interface/isis:fast-reroute/isis:lfa/isis:level-2: +--rw ti-lfa {ti-lfa}? +--rw enabled? 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* [] +--ro value? uint32 +--ro address-family? 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 /isis:router-capability: +--ro sr-capability | +--ro sr-capability-flag* identityref | +--ro global-blocks | +--ro global-block* [] | +--ro range-size? rt-types:uint24 | +--ro sid-sub-tlv | +--ro length? uint8 | +--ro (sid)? | +--:(sid-label) | | +--ro label-value? uint32 | +--:(sid-index) | +--ro index-value? uint32 +--ro sr-algorithms | +--ro sr-algorithm* identityref +--ro local-blocks | +--ro local-block* [] | +--ro range-size? rt-types:uint24 | +--ro sid-sub-tlv | +--ro length? uint8 | +--ro (sid)? | +--:(sid-label) | | +--ro label-value? uint32 | +--:(sid-index) | +--ro index-value? 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/isis:instances/isis:instance: +--ro adj-sid-sub-tlvs +--ro adj-sid-sub-tlv* [] +--ro adj-sid-flags | +--ro flag* identityref +--ro weight? uint8 +--ro neighbor-id? isis:system-id +--ro (sid)? +--:(sid-label) | +--ro label-value? uint32 +--:(sid-index) +--ro index-value? uint32 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 /isis:instances/isis:instance: +--ro adj-sid-sub-tlvs +--ro adj-sid-sub-tlv* [] +--ro adj-sid-flags | +--ro flag* identityref +--ro weight? uint8 +--ro neighbor-id? isis:system-id +--ro (sid)? +--:(sid-label) | +--ro label-value? uint32 +--:(sid-index) +--ro index-value? uint32 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 prefix-sid-sub-tlvs +--ro prefix-sid-sub-tlv* [] +--ro prefix-sid-flags | +--ro flag* identityref +--ro algorithm? identityref +--ro (sid)? +--:(sid-label) | +--ro label-value? uint32 +--:(sid-index) +--ro index-value? uint32 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 prefix-sid-sub-tlvs +--ro prefix-sid-sub-tlv* [] +--ro prefix-sid-flags | +--ro flag* identityref +--ro algorithm? identityref +--ro (sid)? +--:(sid-label) | +--ro label-value? uint32 +--:(sid-index) +--ro index-value? uint32 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 prefix-sid-sub-tlvs +--ro prefix-sid-sub-tlv* [] +--ro prefix-sid-flags | +--ro flag* identityref +--ro algorithm? identityref +--ro (sid)? +--:(sid-label) | +--ro label-value? uint32 +--:(sid-index) +--ro index-value? uint32 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 prefix-sid-sub-tlvs +--ro prefix-sid-sub-tlv* [] +--ro prefix-sid-flags | +--ro flag* identityref +--ro algorithm? identityref +--ro (sid)? +--:(sid-label) | +--ro label-value? uint32 +--:(sid-index) +--ro index-value? uint32 augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol/isis:isis/isis:database /isis:levels/isis:lsp: +--ro sid-binding-tlvs | +--ro sid-binding-tlv* [prefix] | +--ro prefix inet:ip-prefix | +--ro range? uint16 | +--ro sid-binding-flags | | +--ro flag* identityref | +--ro prefix-sid-sub-tlvs* [] | | +--ro prefix-sid-sub-tlvs | | +--ro prefix-sid-sub-tlv* [] | | +--ro prefix-sid-flags | | | +--ro flag* identityref | | +--ro algorithm? identityref | | +--ro (sid)? | | +--:(sid-label) | | | +--ro label-value? uint32 | | +--:(sid-index) | | +--ro index-value? uint32 | +--ro sid-sub-tlv* [] | | +--ro sid-sub-tlv | | +--ro length? uint8 | | +--ro (sid)? | | +--:(sid-label) | | | +--ro label-value? uint32 | | +--:(sid-index) | | +--ro index-value? uint32 | +--ro unknown-tlvs | +--ro unknown-tlv* [] | +--ro type? uint16 | +--ro length? uint16 | +--ro value? yang:hex-string +--ro mt-sid-binding-tlvs +--ro mt-sid-binding-tlv* [prefix mt-id] +--ro prefix inet:ip-prefix +--ro range? uint16 +--ro sid-binding-flags | +--ro flag* identityref +--ro prefix-sid-sub-tlvs* [] | +--ro prefix-sid-sub-tlvs | +--ro prefix-sid-sub-tlv* [] | +--ro prefix-sid-flags | | +--ro flag* identityref | +--ro algorithm? identityref | +--ro (sid)? | +--:(sid-label) | | +--ro label-value? uint32 | +--:(sid-index) | +--ro index-value? uint32 +--ro sid-sub-tlv* [] | +--ro sid-sub-tlv | +--ro length? uint8 | +--ro (sid)? | +--:(sid-label) | | +--ro label-value? uint32 | +--:(sid-index) | +--ro index-value? uint32 +--ro unknown-tlvs | +--ro unknown-tlv* [] | +--ro type? uint16 | +--ro length? uint16 | +--ro value? yang:hex-string +--ro mt-id uint16 ]]>