IS-IS YANG Model Augmentations for Additional Features - Release 1
draft-ietf-lsr-isis-yang-augmentation-v1-11
| Document | Type | Active Internet-Draft (lsr WG) | |
|---|---|---|---|
| Authors | Acee Lindem , Yingzhen Qu , Stephane Litkowski | ||
| Last updated | 2025-10-06 | ||
| Replaces | draft-acee-lsr-isis-yang-augmentation-v1 | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Intended RFC status | Proposed Standard | ||
| Formats | |||
| Yang Validation | 0 errors, 0 warnings | ||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | WG Document | |
| Document shepherd | Christian Hopps | ||
| IESG | IESG state | I-D Exists | |
| Consensus boilerplate | Yes | ||
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | chopps@chopps.org |
draft-ietf-lsr-isis-yang-augmentation-v1-11
Internet A. Lindem
Internet-Draft Arrcus, Inc.
Intended status: Standards Track Y. Qu
Expires: 9 April 2026 Futurewei Technologies
S. Litkowski
Cisco Systems
6 October 2025
IS-IS YANG Model Augmentations for Additional Features - Release 1
draft-ietf-lsr-isis-yang-augmentation-v1-11
Abstract
This document defines YANG data modules augmenting the IETF IS-IS
YANG model to provide support for IS-IS Minimum Remaining Lifetime as
defined in RFC 7987, and Signaling Maximum SID Depth Using IS-IS as
defined in RFC 8491.
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 9 April 2026.
Copyright Notice
Copyright (c) 2025 IETF Trust and the persons identified as the
document authors. All rights reserved.
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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 diagram . . . . . . . . . . . . . . . . . . . . . . 3
2. YANG Module for IS-IS Minimum Remaining Lifetime . . . . . . 3
3. YANG Module for IS-IS Flexible Algorithms: Bandwidth, Delay,
Metrics and Constraints . . . . . . . . . . . . . . . . . 5
4. YANG Module for IS-IS Maximum SID Depth . . . . . . . . . . . 18
5. Security Considerations . . . . . . . . . . . . . . . . . . . 22
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 23
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 24
8. Normative References . . . . . . . . . . . . . . . . . . . . 24
9. Informative References . . . . . . . . . . . . . . . . . . . 26
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 26
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 YANG data modules augmenting the IETF IS-IS
YANG model [RFC9130], which itself augments [RFC8349], to provide
support for configuration and operational state for the following IS-
IS features:
RFC7987: IS-IS Minimum Remaining Lifetime[RFC7987].
RFC8491: Signaling Maximum SID Depth (MSD) Using IS-IS [RFC8491].
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The augmentations defined in this document require support for the
IS-IS base model[RFC9130], which specifies the basic IS-IS
configuration and state. The IS-IS YANG model augments the ietf-
routing YANG model defined in [RFC8349].
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 diagram
Tree diagrams used in this document follow the notation defined in
[RFC8340].
2. YANG Module for IS-IS Minimum Remaining Lifetime
This document defines a YANG module for IS-IS Minimum Remaining
Lifetime as defined in [RFC7987]. It is an augmentation of the IS-IS
base model.
module: ietf-isis-remaining-lifetime
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/isis:isis/isis:database
/isis:levels/isis:lsp:
+--ro received-remaining-lifetime? uint16
notifications:
+---n corrupt-remaining-lifetime
+--ro routing-protocol-name? leafref
+--ro isis-level? level
+--ro lsp-id? isis:lsp-id
<CODE BEGINS> file "ietf-isis-remaining-lifetime@2025-10-06.yang"
module ietf-isis-remaining-lifetime {
yang-version 1.1;
namespace
"urn:ietf:params:xml:ns:yang:ietf-isis-remaining-lifetime";
prefix isis-remaining-lifetime;
import ietf-isis {
prefix "isis";
reference
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"RFC 9130: YANG Data Model for the IS-IS Protocol";
}
import ietf-routing {
prefix "rt";
reference "RFC 8349: A YANG Data Model for Routing
Management (NMDA Version)";
}
organization
"IETF LSR - Link State Routing Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/lsr>
WG List: <mailto:lsr@ietf.org>
Author: Yingzhen Qu
<mailto:yingzhen.ietf@gmail.com>
Author: Acee Lindem
<mailto:acee.ietf@gmail.com>
Author: Stephane Litkowski
<mailto:slitkows.ietf@gmail.com>";
description
"This YANG module defines a notification which is sent when the
IS-IS system detects corrupted lifetime of an LSP. This is for
IS-IS Minimum Remaining Lifetime feature as defined in RFC 7987.
Copyright (c) 2024 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject to
the license terms contained in, the Revised BSD License set
forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(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.";
reference "RFC XXXX";
revision 2025-10-06 {
description
"Initial version";
reference
"RFC XXXX: A YANG Data Model for IS-IS Minimum Remaining
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Lifetime.";
}
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/isis:isis/isis:database/"
+ "isis:levels/isis:lsp" {
leaf received-remaining-lifetime {
type uint16;
units "seconds";
description
"Remaining lifetime of this LSP at the time
it was received.";
}
description
"Preserve the remaining lifetime of this LSP when
it was received.";
}
notification corrupt-remaining-lifetime {
uses isis:notification-instance-hdr;
leaf lsp-id {
type isis:lsp-id;
description "LSP ID";
}
description
"This notification is sent when the system
detects corrupted lifetime of an LSP.";
reference "RFC 7987: IS-IS Minimum Remaining Lifetime";
}
}
<CODE ENDS>
3. YANG Module for IS-IS Flexible Algorithms: Bandwidth, Delay, Metrics
and Constraints
This document defines a YANG module for IS-IS Flexible Algorithms:
Bandwidth, Delay, Metrics and Constraints
[I-D.ietf-lsr-flex-algo-bw-con]. It is an augmentation of the IS-IS
base model and the Flexible Algorithm YANG module .
module: ietf-isis-flex-algo-bw-con
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/isis:isis/isis:interfaces
/isis:interface:
+--rw generic-metrics
+--rw generic-metric* [metric-type]
+--rw metric-type identityref
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+--rw metric-value? uint32
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/isis:isis
/isis-flex-algo:isis-flex-algo:
+--rw bandwidth-constraints
| +--rw constraint* [constraint-type]
| +--rw constraint-type identityref
| +--rw bandwidth-value? te-types:te-bandwidth
| +--rw threshold? uint8
+--rw (metric-derivation-method)?
| +--:(reference-bandwidth)
| | +--rw reference-bandwidth
| | +--rw reference-bandwidth?
| | | rt-types:bandwidth-ieee-float32
| | +--rw granularity-bandwidth?
| | rt-types:bandwidth-ieee-float32
| +--:(bandwidth-thresholds)
| +--rw bandwidth-thresholds
| +--rw bandwidth-threshold* [bandwidth-threshold]
| +--rw bandwidth-threshold
| | rt-types:bandwidth-ieee-float32
| +--rw threshold-metric? rt-types:uint24
+--rw exclude-min-bw?
| rt-types:bandwidth-ieee-float32
+--rw exclude-max-delay? rt-types:uint24
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 generic-metric-sub-tlvs
+--ro generic-metric-sub-tlv* []
+--ro metric-type? identityref
+--ro value? isis:wide-metric
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
/isis-link-attr:asla-sub-tlvs
/isis-link-attr:asla-sub-tlv:
+--ro generic-metric-sub-tlvs
+--ro generic-metric-sub-tlv* []
+--ro metric-type? identityref
+--ro value? isis:wide-metric
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 generic-metric-sub-tlvs
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+--ro generic-metric-sub-tlv* []
+--ro metric-type? identityref
+--ro value? isis:wide-metric
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
/isis-link-attr:asla-sub-tlvs
/isis-link-attr:asla-sub-tlv:
+--ro generic-metric-sub-tlvs
+--ro generic-metric-sub-tlv* []
+--ro metric-type? identityref
+--ro value? isis:wide-metric
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/isis:isis/isis:database
/isis:levels/isis:lsp/isis:router-capabilities
/isis-flex-algo:fad-tlvs/isis-flex-algo:fad-tlv:
+--ro faemb-sub-tlv
| +--ro min-bandwidth? rt-types:bandwidth-ieee-float32
+--ro faemd-sub-tlv
| +--ro max-link-delay? rt-types:uint24
+--ro fadrb-sub-tlv
| +--ro fadrb-flags* identityref
| +--ro reference-bandwidth?
| | rt-types:bandwidth-ieee-float32
| +--ro granularity-bandwidth?
| rt-types:bandwidth-ieee-float32
+--ro fadbt-sub-tlv
+--ro fadbt-flags* identityref
+--ro bandwidth-threshold* []
+--ro bandwidth-threshold?
| rt-types:bandwidth-ieee-float32
+--ro threshold-metric? rt-types:uint24
<CODE BEGINS> file "ietf-isis-flex-algo-bw-con@2025-10-06.yang"
module ietf-isis-flex-algo-bw-con {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:"
+ "ietf-isis-flex-algo-bw-con";
prefix isis-flex-algo-bw;
import ietf-routing {
prefix rt;
reference "RFC 8349: A YANG Data Model for Routing
Management (NMDA Version)";
}
import ietf-routing-types {
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prefix "rt-types";
reference "RFC 8294: Common YANG Data Types for the
Routing Area";
}
import ietf-te-types {
prefix te-types;
reference
"RFC8776: Common YANG Data Types for Traffic Engineering.";
}
import ietf-isis {
prefix isis;
reference
"RFC 9130: YANG Data Model for the IS-IS Protocol";
}
import ietf-isis-flex-algo {
prefix isis-flex-algo;
}
import ietf-isis-link-attr {
prefix isis-link-attr;
}
import iana-igp-metric-types {
prefix iana-metric-types;
}
organization
"IETF LSR - Link State Routing Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/lsr/>
WG List: <mailto:lsr@ietf.org>
Author: Yingzhen Qu
<mailto:yingzhen.ietf@gmail.com>
Author: Acee Lindem
<mailto:acee.ietf@gmail.com>
";
description
"The YANG module defines the configuration and operational
state for IS-IS protocol as defined in
draft-ietf-lsr-flex-algo-bw-con, IGP Flexible Algorithms:
Bandwidth, Delay, Metrics and Constraints
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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;
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.";
reference "RFC XXXX.";
revision 2025-10-06 {
description
"Initial Version";
reference
"RFC XXXX";
}
/* Identities */
identity bandwidth-constraint-type {
description
"Base identity for bandwidth constraint types.";
}
identity min-bw {
base bandwidth-constraint-type;
description
"Minimum bandwidth constraint.";
}
identity max-bw {
base bandwidth-constraint-type;
description
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"Maximum bandwidth constraint.";
}
identity fadrb-flags {
description
"Base identity for OSPF Flexible Algorithm Definition
Reference Bandwidth sub-tlv flags.";
}
identity g-bit {
base fadrb-flags;
description
"G bit, when set, interface group mode MUST be used to
derive total link bandwidth.";
}
identity fadbt-flags {
description
"Base identity for OSPF Flexible Algorithm Definition
Reference Bandwidth sub-tlv flags.";
}
identity gp-bit {
base fadbt-flags;
description
"G bit, when set, interface group mode MUST be used to
derive total link bandwidth.";
}
/* Groupings */
grouping bandwidth-constraint {
description
"Grouping for bandwidth constraints in Flex-Algo.";
container bandwidth-constraints {
list constraint {
key "constraint-type";
description
"List of bandwidth constraints for the Flex-Algo.";
leaf constraint-type {
type identityref {
base bandwidth-constraint-type;
}
description
"Type of bandwidth constraint (e.g., min-bw, max-bw).";
}
leaf bandwidth-value {
type te-types:te-bandwidth;
description
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"Bandwidth value for the constraint.";
}
leaf threshold {
type uint8 {
range "1..100";
}
units "percent";
description
"Threshold percentage for triggering re-optimization.";
}
}
description
"Bandwidth constraints configuration for flex-algo.";
}
}
grouping generic-metric-sub-tlv {
container generic-metric-sub-tlvs {
list generic-metric-sub-tlv {
leaf metric-type {
type identityref {
base iana-metric-types:metric-type;
}
description
"Type of metric to be used during the calculation.";
}
leaf value {
type isis:wide-metric;
description
"A 24-bit unsigned integer representing the metric
value. The valid range is from 0 to 16,777,215
(0xFFFFFF).";
}
description
"The list of generic metric sub-tlvs.";
}
description
"The generic metric sub-tlv.";
}
description
"The grouping for generic metric sub-tlv.";
}
grouping faemb-sub-tlv {
container faemb-sub-tlv {
leaf min-bandwidth {
type rt-types:bandwidth-ieee-float32;
description
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"A 32-bit field specifying the link bandwidth in IEEE
floating point format (IEEE754). The units are
bytes-per-second.";
}
description
"Flex-algo Exclude Minimum Bandwidth sub-tlv (FAEMB).";
}
description
"Grouping for FAEMB sub-tlv.";
}
grouping faemd-sub-tlv {
container faemd-sub-tlv {
leaf max-link-delay {
type rt-types:uint24;
description
"A 24-bit field specifying the maximum link delay in
microseconds.";
}
description
"The Flex-algo Exclude Maximum Delay sub-tlv (FAEMD).";
}
description
"Grouping for FAEMD sub-tlv.";
}
grouping fadrb-sub-tlv {
container fadrb-sub-tlv {
leaf-list fadrb-flags {
type identityref {
base fadrb-flags;
}
description
"Flex-algo definition reference bandwidth sub-tlv
flags list.";
}
leaf reference-bandwidth {
type rt-types:bandwidth-ieee-float32;
description
"A 32-bit field specifying the link bandwidth in IEEE
floating point format (IEEE754). The units are
bytes-per-second.";
}
leaf granularity-bandwidth {
type rt-types:bandwidth-ieee-float32;
description
"A 32-bit field specifying the link bandwidth in IEEE
floating point format (IEEE754). The units are
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bytes-per-second.";
}
description
"The Flex-algo Reference Bandwidth sub-tlv (FAEMD).";
}
description
"Grouping for FADRB sub-tlv.";
}
grouping fadbt-sub-tlv {
container fadbt-sub-tlv {
leaf-list fadbt-flags {
type identityref {
base fadbt-flags;
}
description
"Flex-algo definition bandwidth thresholds sub-tlv
flags list.";
}
list bandwidth-threshold {
leaf bandwidth-threshold {
type rt-types:bandwidth-ieee-float32;
description
"Maximum link bandwidth. A 32-bit field specifying
the link bandwidth in IEEE floating point format
(IEEE754). The units are bytes-per-second.";
}
leaf threshold-metric {
type rt-types:uint24;
description
"Metric value range 1 - 16,777,215 (0xFFFFFF).";
}
description
"List of bandwidth thresholds and metrics.";
}
description
"The Flex-algo Bandwidth Thresholds sub-tlv (FADBT).";
}
description
"Grouping for FADBT sub-tlv.";
}
/* Configurations */
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/isis:isis/"
+ "isis:interfaces/isis:interface" {
when "/rt:routing/rt:control-plane-protocols/"
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+ "rt:control-plane-protocol/rt:type = 'isis:isis'" {
description
"This augment ISIS routing protocol when used.";
}
description
"This augments the ISIS protocol interface
configuration with generic metric configuration.";
container generic-metrics {
list generic-metric {
key "metric-type";
leaf metric-type {
type identityref {
base iana-metric-types:metric-type;
}
description
"Type of metric to be used during the calculation.";
}
leaf metric-value {
type uint32;
description
"Metric value, range is from 0 to 0xFFFFFFFF.";
}
description
"Interface generic metric configuration per metric-type.";
}
description
"Interface generic metric configuration.";
}
}
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/isis:isis/"
+ "isis-flex-algo:isis-flex-algo" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'isis:isis')" {
description
"This augments the ISIS routing protocol when used.";
}
description
"This augments ISIS protocol Flexible Algorithm with
bandwidth constraints.";
uses bandwidth-constraint;
choice metric-derivation-method {
description
"Choice of automatic metric derivation methods.";
container reference-bandwidth {
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description
"Metric is inversely proportional to the link
bandwidth.";
leaf reference-bandwidth {
type rt-types:bandwidth-ieee-float32;
description
"A 32-bit field specifying the link bandwidth in IEEE
floating point format (IEEE754). The units are
bytes-per-second.";
}
leaf granularity-bandwidth {
type rt-types:bandwidth-ieee-float32;
description
"A 32-bit field specifying the link bandwidth in IEEE
floating point format (IEEE754). The units are
bytes-per-second.";
}
}
container bandwidth-thresholds {
description
"Pre-define non-proportional metric values from the
varying ranges of link bandwidth.";
list bandwidth-threshold {
key bandwidth-threshold;
leaf bandwidth-threshold {
type rt-types:bandwidth-ieee-float32;
description
"Maximum link bandwidth. A 32-bit field specifying
the link bandwidth in IEEE floating point format
(IEEE754). The units are bytes-per-second.";
}
leaf threshold-metric {
type rt-types:uint24;
description
"Metric value range 1 - 16,777,215 (0xFFFFFF).";
}
description
"List of bandwidth thresholds and metrics.";
}
}
}
leaf exclude-min-bw {
type rt-types:bandwidth-ieee-float32;
description
"A 32-bit field specifying the link bandwidth in IEEE
floating point format (IEEE754). The units are
bytes-per-second.";
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}
leaf exclude-max-delay {
type rt-types:uint24;
description
"A 24-bit field specifying the maximum link delay in
microseconds.";
}
}
/* Database */
/* TLV 22 */
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 "/rt:routing/rt:control-plane-protocols/"+
"rt:control-plane-protocol/rt:type = 'isis:isis'" {
description
"This augment ISIS routing protocol when used";
}
description
"This augments ISIS protocol LSDB TLV22.";
uses generic-metric-sub-tlv;
}
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"+
"/isis-link-attr:asla-sub-tlvs"+
"/isis-link-attr:asla-sub-tlv" {
when "/rt:routing/rt:control-plane-protocols/"+
"rt:control-plane-protocol/rt:type = 'isis:isis'" {
description
"This augment ISIS routing protocol when used";
}
description
"This augments ISIS protocol LSDB TLV22 asla-sub-tlv.";
uses generic-metric-sub-tlv;
}
/* TLV 223 */
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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 "/rt:routing/rt:control-plane-protocols/"+
"rt:control-plane-protocol/rt:type = 'isis:isis'" {
description
"This augment ISIS routing protocol when used";
}
description
"This augments ISIS protocol LSDB TLV223.";
uses generic-metric-sub-tlv;
}
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"+
"/isis-link-attr:asla-sub-tlvs"+
"/isis-link-attr:asla-sub-tlv" {
when "/rt:routing/rt:control-plane-protocols/"+
"rt:control-plane-protocol/rt:type = 'isis:isis'" {
description
"This augment ISIS routing protocol when used";
}
description
"This augments ISIS protocol LSDB TLV223 asla-sub-tlv.";
uses generic-metric-sub-tlv;
}
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/"
+ "isis:isis/isis:database/isis:levels/isis:lsp/"
+ "isis:router-capabilities/isis-flex-algo:fad-tlvs/"
+ "isis-flex-algo:fad-tlv" {
when "/rt:routing/rt:control-plane-protocols/"+
"rt:control-plane-protocol/"+
"rt:type = 'isis:isis'" {
description
"This augment ISIS routing protocol when used";
}
description
"This augments ISIS protocol LSDB router capability.";
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uses faemb-sub-tlv;
uses faemd-sub-tlv;
uses fadrb-sub-tlv;
uses fadbt-sub-tlv;
}
}
4. YANG Module for IS-IS Maximum SID Depth
This document defines a module for Signaling Maximum SID Depth (MSD)
using IS-IS [RFC8491]. It is an augmentation of the IS-IS base
model.
The figure below describes the overall structure of the isis-msd YANG
module:
module: ietf-isis-msd
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 node-msd-tlv
+--ro node-msds* [msd-type]
+--ro msd-type identityref
+--ro msd-value? 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 link-msd-sub-tlv
+--ro link-msds* [msd-type]
+--ro msd-type identityref
+--ro msd-value? uint8
+--ro msd-raw-value? uint8
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 link-msd-sub-tlv
+--ro link-msds* [msd-type]
+--ro msd-type identityref
+--ro msd-value? uint8
+--ro msd-raw-value? uint8
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<CODE BEGINS> file "ietf-isis-msd@2025-10-06.yang"
module ietf-isis-msd {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-isis-msd";
prefix isis-msd;
import ietf-routing {
prefix rt;
reference
"RFC 8349: A YANG Data Model for Routing
Management (NMDA Version)";
}
import ietf-isis {
prefix isis;
reference
"RFC 9130: YANG Data Model for the IS-IS Protocol";
}
import ietf-mpls-msd {
prefix mpls-msd;
}
organization
"IETF LSR - LSR Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/lsr>
WG List: <mailto:lsr@ietf.org>
Author: Yingzhen Qu
<mailto:yingzhen.ietf@gmail.com>
Author: Acee Lindem
<mailto:acee.ietf@gmail.com>
Author: Stephane Litkowski
<mailto:slitkows.ietf@gmail.com>
Author: Jeff Tantsura
<mailto:jefftant.ietf@gmail.com>
";
description
"The YANG module augments the base ISIS model to
manage different types of MSDs.
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.
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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.";
reference
"RFC XXXX: YANG Data Model for ISIS MSD";
revision 2025-10-06 {
description
"Initial Version";
reference
"RFC XXXX: YANG Data Model for ISIS MSD.";
}
grouping link-msd-sub-tlv {
description
"Link Maximum SID Depth (MSD) grouping for an interface.";
container link-msd-sub-tlv {
list link-msds {
key "msd-type";
uses mpls-msd:msd-type-value;
leaf msd-raw-value {
type uint8;
description
"MSD integer value.";
}
description
"List of link MSDs";
}
description
"Link MSD sub-tlvs.";
}
}
/* Node MSD TLV */
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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 augment ISIS routing protocol when used";
}
description
"This augments ISIS protocol LSDB router capability.";
container node-msd-tlv {
list node-msds {
key "msd-type";
uses mpls-msd:msd-type-value;
description
"Node MSD is the smallest link MSD supported by
the node.";
}
description
"Node MSD is the number of SIDs supported by a node.";
reference
"RFC 8491: Signaling Maximum SID Depth (MSD) Using IS-IS";
}
}
/* link MSD sub-tlv */
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 augment ISIS routing protocol when used";
}
description
"This augments ISIS protocol LSDB neighbor with
Link MSD sub-TLV.";
uses link-msd-sub-tlv;
}
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"
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+ "/isis:instances/isis:instance" {
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 link-msd-sub-tlv;
}
}
<CODE ENDS>
5. Security Considerations
The YANG modules specified in this document define 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 [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 the modules 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 correspond to the following
schema nodes:
/isis:isis/isis:interfaces/isis:interface/isis-link-attr -
Modification of link attributes operation mode could result in
traffic being redirected or DoS attack.
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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. The exposure of the Link State
Database (LSDB) will expose the detailed topology of the network.
This may be undesirable since both due to the fact that exposure may
facilitate other attacks. Additionally, network operators may
consider their topologies to be sensitive confidential data.These
correspond to the following schema nodes:
/isis:isis/isis:database/isis:levels/isis:lsp/isis:mt-is-
neighbor/isis:neighbor/isis:instances/isis:instance/application-
specific-link-attributes-sub-tlvs
/isis:isis/isis:database/isis:levels/isis:lsp/application-
specific-srlg-tlv
/isis:router-capabilities/node-msd-tlv
/isis:isis/isis:database/isis:levels/isis:lsp//isis:extended-is-
neighbor/isis:neighbor/link-msd-sub-tlv
/isis:isis/isis:database/isis:levels/isis:lsp//isis:mt-is-
neighbor/isis:neighbor/link-msd-sub-tlv
6. IANA Considerations
This document registers URIs in the IETF XML registry [RFC3688].
Following the format in [RFC3688], the following registrations is
requested to be made:
URI: urn:ietf:params:xml:ns:yang:ietf-isis-remaining-lifetime
Registrant Contact: The IESG.
XML: N/A, the requested URI is an XML namespace.
URI: urn:ietf:params:xml:ns:yang:ietf-isis-flex-algo-bw-con
Registrant Contact: The IESG.
XML: N/A, the requested URI is an XML namespace.
URI: urn:ietf:params:xml:ns:yang:ietf-isis-msd
Registrant Contact: The IESG.
XML: N/A, the requested URI is an XML namespace
This document registers the YANG modules in the YANG Module Names
registry [RFC6020].
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name: ietf-isis-remaining-lifetime
namespace: urn:ietf:params:xml:ns:yang:ietf-isis-remaining-lifetime
prefix: isis-remaining-lifetime
reference: RFC XXXX
name: ietf-isis-flex-algo-bw-con
namespace: urn:ietf:params:xml:ns:yang:ietf-isis-flex-algo-bw-con
prefix: isis-flex-algo-bw-con
reference: RFC XXXX
name: ietf-isis-msd
namespace: urn:ietf:params:xml:ns:yang:ietf-isis-msd
prefix: isis-msd
reference: RFC XXXX
7. Acknowledgements
The YANG model was developed using the suite of YANG tools written
and maintained by numerous authors.
Thanks to Renato Westphal for review, comments, and implementation.
8. Normative References
[I-D.ietf-lsr-flex-algo-bw-con]
Hegde, S., Britto, W., Shetty, R., Decraene, B., Psenak,
P., and T. Li, "IGP Flexible Algorithms: Bandwidth, Delay,
Metrics and Constraints", Work in Progress, Internet-
Draft, draft-ietf-lsr-flex-algo-bw-con-22, 13 February
2025, <https://datatracker.ietf.org/doc/html/draft-ietf-
lsr-flex-algo-bw-con-22>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
the Network Configuration Protocol (NETCONF)", RFC 6020,
DOI 10.17487/RFC6020, October 2010,
<https://www.rfc-editor.org/info/rfc6020>.
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[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,
<https://www.rfc-editor.org/info/rfc6241>.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure
Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
<https://www.rfc-editor.org/info/rfc6242>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/info/rfc7950>.
[RFC7987] Ginsberg, L., Wells, P., Decraene, B., Przygienda, T., and
H. Gredler, "IS-IS Minimum Remaining Lifetime", RFC 7987,
DOI 10.17487/RFC7987, October 2016,
<https://www.rfc-editor.org/info/rfc7987>.
[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
<https://www.rfc-editor.org/info/rfc8040>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration
Access Control Model", STD 91, RFC 8341,
DOI 10.17487/RFC8341, March 2018,
<https://www.rfc-editor.org/info/rfc8341>.
[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,
<https://www.rfc-editor.org/info/rfc8349>.
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>.
[RFC8491] Tantsura, J., Chunduri, U., Aldrin, S., and L. Ginsberg,
"Signaling Maximum SID Depth (MSD) Using IS-IS", RFC 8491,
DOI 10.17487/RFC8491, November 2018,
<https://www.rfc-editor.org/info/rfc8491>.
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[RFC9130] Litkowski, S., Ed., Yeung, D., Lindem, A., Zhang, J., and
L. Lhotka, "YANG Data Model for the IS-IS Protocol",
RFC 9130, DOI 10.17487/RFC9130, October 2022,
<https://www.rfc-editor.org/info/rfc9130>.
9. Informative References
[RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
<https://www.rfc-editor.org/info/rfc8340>.
Authors' Addresses
Acee Lindem
Arrcus, Inc.
301 Midenhall Way
Cary, NC 27513
Email: acee.ietf@gmail.com
Yingzhen Qu
Futurewei Technologies
United States of America
Email: yingzhen.ietf@gmail.com
Stephane Litkowski
Cisco Systems
Email: slitkows.ietf@gmail.com
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