A YANG Data Model for IS-IS Application-Specific Link Attributes and Flexible Algorithm
draft-ietf-lsr-isis-flex-algo-yang-19
| Document | Type | Active Internet-Draft (lsr WG) | |
|---|---|---|---|
| Authors | Yingzhen Qu , Acee Lindem , Madhavi Joshi | ||
| Last updated | 2026-07-02 | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Intended RFC status | Proposed Standard | ||
| Formats | |||
| Yang Validation | 0 errors, 0 warnings | ||
| Reviews |
YANGDOCTORS Early review
(of
-00)
by Michal Vaško
Ready w/issues
SECDIR IETF Last Call Review due 2026-03-30
Incomplete
|
||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | Submitted to IESG for Publication | |
| Document shepherd | Christian Hopps | ||
| Shepherd write-up | Show Last changed 2026-02-03 | ||
| IESG | IESG state | IESG Evaluation::AD Followup | |
| Action Holder | |||
| Consensus boilerplate | Yes | ||
| Telechat date |
(None)
Has a DISCUSS. Has enough positions to pass once DISCUSS positions are resolved. |
||
| Responsible AD | Gunter Van de Velde | ||
| Send notices to | chopps@chopps.org | ||
| IANA | IANA review state | Version Changed - Review Needed | |
| IANA expert review state | Expert Reviews OK |
draft-ietf-lsr-isis-flex-algo-yang-19
Internet Y. Qu
Internet-Draft Futurewei Technologies
Intended status: Standards Track A. Lindem
Expires: 3 January 2027 M. Joshi
Arrcus, Inc.
2 July 2026
A YANG Data Model for IS-IS Application-Specific Link Attributes and
Flexible Algorithm
draft-ietf-lsr-isis-flex-algo-yang-19
Abstract
This document defines a YANG data model to support IS-IS Application-
Specific Link Attributes and Flexible Algorithm.
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 3 January 2027.
Copyright Notice
Copyright (c) 2026 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
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.
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Table of Contents
1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
2. YANG Module for IS-IS Application-Specific Link Attributes . 3
3. YANG Module for IS-IS Flexible Algorithm . . . . . . . . . . 16
4. Security Considerations . . . . . . . . . . . . . . . . . . . 27
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 28
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 29
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 29
7.1. Normative References . . . . . . . . . . . . . . . . . . 29
7.2. Informative References . . . . . . . . . . . . . . . . . 31
Appendix A. Example IS-IS Flex-Algo Configuration . . . . . . . 32
Appendix B. Example IS-IS Flex-Algo Configuration (JSON) . . . . 33
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 34
1. Overview
This document defines a YANG [RFC7950] data model, which is composed
of two YANG modules. The first module provides support for
configuration and operational state for IS-IS Application-Specific
Link Attributes as defined in [RFC9479], and the second module
supports IS-IS Flexible Algorithm as defined in [RFC9350]. Both
modules augment the IETF IS-IS YANG data model [RFC9130].
The first YANG module, ietf-isis-link-attr, augments the IS-IS YANG
data model [RFC9130] to support configuration and operational state
for IS-IS Application-Specific Link Attributes (ASLA) as specified in
[RFC9479]. This module is related to the IS-IS TE extensions defined
in [RFC5305] and reuses identity definitions from the IANA-maintained
IGP link-attribute application registry.
The second YANG module, ietf-isis-flex-algo, augments the IS-IS YANG
data model [RFC9130] to support IS-IS Flexible Algorithm as specified
in [RFC9350]. It uses identity definitions from the IANA-maintained
IGP Algorithm Types and IGP Metric Type registries, and references
the TE YANG data types [RFC8776] for admin-group and SRLG feature
support.
The meanings of the symbols in the YANG tree diagrams are defined in
[RFC8340].
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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.
2. YANG Module for IS-IS Application-Specific Link Attributes
This document defines a YANG module for IS-IS Application-Specific
Link Attributes as defined in [RFC9479]. This YANG module references
[RFC9479], [RFC9911], [RFC8349], [RFC9130], [RFC5305], [RFC8294],
[RFC5307], and [IANA-Link-Attr-Apps].
module: ietf-isis-link-attr
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/isis:isis:
+--rw isis-link-attr
+--rw (link-attr-op-mode)?
+--:(legacy)
| +--rw legacy? empty
+--:(transition)
| +--rw transition? empty
+--:(app-specific)
+--rw app-specific? empty
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/isis:isis/isis:interfaces
/isis:interface:
+--rw isis-asla
+--rw interface-asla* [link-attr-app]
+--rw link-attr-app
| iana-link-attr-apps:igp-link-attr-app
+--rw te-metric? te-types:te-metric
+--rw admin-group? te-types:admin-group
+--rw srlgs
+--rw srlg* te-types:srlg
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 asla-sub-tlvs
+--ro asla-sub-tlv* []
+--ro l-flag? boolean
+--ro sabm
| +--ro sabm-bit* iana-link-attr-apps:igp-link-attr-app
+--ro udabm
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+--ro te-metric?
| te-types:te-metric
+--ro admin-group?
| te-types:admin-group
+--ro max-bandwidth?
| rt-types:bandwidth-ieee-float32
+--ro max-reservable-bandwidth?
| rt-types:bandwidth-ieee-float32
+--ro unreserved-bandwidths
| +--ro unreserved-bandwidth* []
| +--ro priority? uint8
| +--ro unreserved-bandwidth?
| rt-types:bandwidth-ieee-float32
+--ro unidirectional-link-delay
| +--ro flags
| | +--ro unidirectional-link-delay-subtlv-flags*
| | identityref
| +--ro value? uint32
+--ro min-max-unidirectional-link-delay
| +--ro flags
| | +--ro min-max-unidirectional-link-delay-subtlv-flags*
| | identityref
| +--ro min-value? uint32
| +--ro max-value? uint32
+--ro unidirectional-link-delay-variation
| +--ro value? uint32
+--ro unidirectional-link-loss
| +--ro flags
| | +--ro unidirectional-link-loss-subtlv-flags*
| | identityref
| +--ro value? uint32
+--ro unidirectional-link-residual-bandwidth
| +--ro value? rt-types:bandwidth-ieee-float32
+--ro unidirectional-link-available-bandwidth
| +--ro value? rt-types:bandwidth-ieee-float32
+--ro unidirectional-link-utilized-bandwidth
| +--ro value? rt-types:bandwidth-ieee-float32
+--ro unknown-tlvs
+--ro unknown-tlv* []
+--ro type? uint16
+--ro length? uint16
+--ro value? yang:hex-string
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 asla-sub-tlvs
+--ro asla-sub-tlv* []
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+--ro l-flag? boolean
+--ro sabm
| +--ro sabm-bit* iana-link-attr-apps:igp-link-attr-app
+--ro udabm
+--ro te-metric?
| te-types:te-metric
+--ro admin-group?
| te-types:admin-group
+--ro max-bandwidth?
| rt-types:bandwidth-ieee-float32
+--ro max-reservable-bandwidth?
| rt-types:bandwidth-ieee-float32
+--ro unreserved-bandwidths
| +--ro unreserved-bandwidth* []
| +--ro priority? uint8
| +--ro unreserved-bandwidth?
| rt-types:bandwidth-ieee-float32
+--ro unidirectional-link-delay
| +--ro flags
| | +--ro unidirectional-link-delay-subtlv-flags*
| | identityref
| +--ro value? uint32
+--ro min-max-unidirectional-link-delay
| +--ro flags
| | +--ro min-max-unidirectional-link-delay-subtlv-flags*
| | identityref
| +--ro min-value? uint32
| +--ro max-value? uint32
+--ro unidirectional-link-delay-variation
| +--ro value? uint32
+--ro unidirectional-link-loss
| +--ro flags
| | +--ro unidirectional-link-loss-subtlv-flags*
| | identityref
| +--ro value? uint32
+--ro unidirectional-link-residual-bandwidth
| +--ro value? rt-types:bandwidth-ieee-float32
+--ro unidirectional-link-available-bandwidth
| +--ro value? rt-types:bandwidth-ieee-float32
+--ro unidirectional-link-utilized-bandwidth
| +--ro value? rt-types:bandwidth-ieee-float32
+--ro unknown-tlvs
+--ro unknown-tlv* []
+--ro type? uint16
+--ro length? uint16
+--ro value? yang:hex-string
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/isis:isis/isis:database
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/isis:levels/isis:lsp:
+--ro application-specific-srlg-tlv
+--ro as-srlg-tlv* []
+--ro neighbor-system-id? isis:system-id
+--ro pseudo-node-id? uint8
+--ro l-flag? boolean
+--ro sabm
| +--ro sabm-bit* iana-link-attr-apps:igp-link-attr-app
+--ro udabm
+--ro link-id-sub-tlvs
| +--ro link-local-remote-ids
| | +--ro link-local-id? uint32
| | +--ro link-remote-id? uint32
| +--ro ipv4-interface-addr
| | +--ro ipv4-int-addr? inet:ipv4-address
| +--ro ipv4-neighbor-addr
| | +--ro ipv4-neighbor-addr? inet:ipv4-address
| +--ro ipv6-interface-addr
| | +--ro ipv6-int-addr? inet:ipv6-address
| +--ro ipv6-neighbor-addr
| +--ro ipv6-neighbor-addr? inet:ipv6-address
+--ro srlgs
+--ro srlg* te-types:srlg
<CODE BEGINS> file "ietf-isis-link-attr@2026-07-02.yang"
module ietf-isis-link-attr {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-isis-link-attr";
prefix isis-link-attr;
import ietf-inet-types {
prefix inet;
reference
"RFC 9911: Common YANG Data Types";
}
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-routing-types {
prefix rt-types;
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reference
"RFC 8294: Common YANG Data Types for the
Routing Area";
}
import ietf-te-types {
prefix te-types;
reference
"RFC 8776: Common YANG Data Types for Traffic Engineering";
}
import iana-igp-link-attr-apps {
prefix iana-link-attr-apps;
reference
"IANA IGP Link-Attribute Application Identifiers registry,
<https://www.iana.org/assignments/igp-parameters>.";
}
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: Madhavi Joshi
<mailto:madhavi@arrcus.com>
";
description
"This YANG module defines the configuration and operational
state for IS-IS application specific link attributes feature as
defined in RFC 9479.
Copyright (c) 2026 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).
All revisions of IETF and IANA published modules can be found
at the YANG Parameters registry group
(https://www.iana.org/assignments/yang-parameters).
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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.";
revision 2026-07-02 {
description
"Initial version";
reference
"RFC XXXX: A YANG Data Model for IS-IS Application-Specific
Link Attributes and Flexible Algorithm";
}
grouping isis-te-link-attrs {
description
"IS-IS Application-Specific Link Attributes (ASLA)
inherited from the base IS-IS TE attributes";
leaf te-metric {
type te-types:te-metric;
description
"TE default metric.";
reference
"RFC 5305: IS-IS Extensions for Traffic Engineering,
Section 3.7";
}
leaf admin-group {
type te-types:admin-group;
description
"Administrative Group / Resource Class/Color.";
reference
"RFC 5305: IS-IS Extensions for Traffic Engineering,
Section 3.1";
}
leaf max-bandwidth {
type rt-types:bandwidth-ieee-float32;
units "bytes per second";
description
"Maximum bandwidth.";
reference
"RFC 5305: IS-IS Extensions for Traffic Engineering,
Section 3.4";
}
leaf max-reservable-bandwidth {
type rt-types:bandwidth-ieee-float32;
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units "bytes per second";
description
"Maximum reservable bandwidth.";
reference
"RFC 5305: IS-IS Extensions for Traffic Engineering,
Section 3.5";
}
container unreserved-bandwidths {
description
"All unreserved bandwidths.";
list unreserved-bandwidth {
leaf priority {
type uint8 {
range "0..7";
}
description
"Priority from 0 to 7. There should only be a single
unreserved-bandwidth per priority.";
}
leaf unreserved-bandwidth {
type rt-types:bandwidth-ieee-float32;
units "bytes per second";
description
"Unreserved bandwidth.";
}
description
"List of unreserved bandwidths for different
priorities.";
}
reference
"RFC 5305: IS-IS Extensions for Traffic Engineering,
Section 3.6";
}
reference
"RFC 5305: IS-IS Extensions for Traffic Engineering";
}
grouping application-identifier-bit-mask {
description
"Identification of the set of applications associated with
link attribute advertisements";
leaf l-flag {
type boolean;
description
"Legacy Flag. When the SABM Length or UDABM Length is
non-zero and the L-flag is not set, all applications
specified in the bit mask use the link
attribute advertisements in the sub-TLV.";
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reference
"RFC 9479: IS-IS Application-Specific Link Attributes,
Section 3";
}
container sabm {
leaf-list sabm-bit {
type iana-link-attr-apps:igp-link-attr-app;
description
"Standard Application Identifier Bit Mask bits. This
leaf-list contains identities for the bits which are
set to 1 in the SABM field.";
}
description
"Standard Application Identifier Bit Mask.";
}
container udabm {
description
"User Defined Application Identifier Bit Mask (UDABM).
This container is intended to be augmented by documents
defining user-defined application identifiers. Each
such augmentation SHOULD add a leaf-list of identityref
type whose base identity represents the user-defined
application, following the same pattern as the
'sabm-bit' leaf-list. Refer to RFC 9479, Section 3
for the on-wire encoding of the UDABM field.";
reference
"RFC 9479: IS-IS Application-Specific Link Attributes,
Section 3";
}
}
grouping application-specific-link-attributes-sub-tlv {
description
"Grouping for specification of the applications and
application-specific attribute values.";
container asla-sub-tlvs {
list asla-sub-tlv {
uses application-identifier-bit-mask;
uses isis-te-link-attrs;
uses isis:neighbor-extended-te-extensions;
uses isis:unknown-tlvs;
description
"List of application specific link attributes sub-tlvs.";
}
description
"Application specific link attributes sub-tlv.";
}
}
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grouping application-specific-srlg-tlv {
description
"Grouping of a TLV to advertise application-specific
SRLGs for a given link.";
container application-specific-srlg-tlv {
list as-srlg-tlv {
leaf neighbor-system-id {
type isis:system-id;
description
"Neighbor System-ID.";
}
leaf pseudo-node-id {
type uint8;
description
"Pseudo-node ID.";
}
uses application-identifier-bit-mask;
container link-id-sub-tlvs {
description
"Link Identifier sub-TLVs.";
container link-local-remote-ids {
description
"Link local/remote identifiers sub-tlv.";
leaf link-local-id {
type uint32;
description
"Local identifier of the link.";
}
leaf link-remote-id {
type uint32;
description
"Remote identifier of the link. If the Link
Remote Identifier is unknown, it is set to 0.";
}
}
container ipv4-interface-addr {
leaf ipv4-int-addr {
type inet:ipv4-address;
description
"IPv4 address for the interface.";
}
description
"IPv4 interface address sub-tlv.";
}
container ipv4-neighbor-addr {
leaf ipv4-neighbor-addr {
type inet:ipv4-address;
description
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"IPv4 address for a neighboring router
on this link.";
}
description
"IPv4 neighbor address sub-tlv.";
}
container ipv6-interface-addr {
leaf ipv6-int-addr {
type inet:ipv6-address;
description
"IPv6 address for the interface.";
}
description
"IPv6 interface address sub-tlv.";
}
container ipv6-neighbor-addr {
leaf ipv6-neighbor-addr {
type inet:ipv6-address;
description
"IPv6 address for a neighboring router
on this link.";
}
description
"IPv6 neighbor address sub-tlv.";
}
reference
"RFC 5307 - IS-IS Extensions in Support of Generalized
Multi-Protocol Label Switching (GMPLS)";
}
container srlgs {
description
"List of SRLGs.";
leaf-list srlg {
type te-types:srlg;
description
"SRLG value of the link.";
}
}
description
"List of application specific SRLG tlvs.";
}
description
"Application specific SRLG tlv.";
}
}
/* Management */
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augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol"
+ "/isis:isis" {
when "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type = 'isis:isis'" {
description
"This augments the IS-IS routing protocol when used";
}
description
"This augments the IS-IS protocol management
with application specific link attributes.";
container isis-link-attr {
choice link-attr-op-mode {
default "app-specific";
leaf legacy {
type empty;
description
"Only send legacy advertisements, and no ASLA
advertisement.";
}
leaf transition {
type empty;
description
"Send both application-specific and legacy
advertisements,and they should have identical
information.";
}
leaf app-specific {
type empty;
description
"Only send application-specific advertisements.";
}
description
"Link attributes mode. Default to app-specific consistent
with implementations. This is the enablement knob
for ASLA advertisement at the protocol level. Please
refer to Section 6.3 of RFC9479 for details.";
}
description
"Application specific link attributes.";
reference
"RFC 9479 - IS-IS Application-Specific Link Attributes";
}
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol"
+ "/isis:isis/isis:interfaces/isis:interface" {
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when "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/"
+ "rt:type = 'isis:isis'" {
description
"This augments the IS-IS routing protocol when used.";
}
description
"This augments the IS-IS interface management
with application specific link attributes.";
container isis-asla {
list interface-asla {
key "link-attr-app";
leaf link-attr-app {
type iana-link-attr-apps:igp-link-attr-app;
description
"Application-specific attributes. Note that
when encoded, applications with identical
attributes may be included in the same sub-TLV.";
}
leaf te-metric {
type te-types:te-metric;
description
"TE metric.";
reference
"RFC 5305: IS-IS Extensions for Traffic Engineering";
}
leaf admin-group {
type te-types:admin-group;
description
"Administrative Group / Resource Class/Color.";
reference
"RFC 5305: IS-IS Extensions for Traffic Engineering";
}
container srlgs {
description
"List of SRLGs.";
leaf-list srlg {
type te-types:srlg;
description
"SRLG value of the link.";
}
}
description
"ASLA interface configuration.";
}
description
"Application specific link attributes configuration.";
}
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}
/* 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 augments the IS-IS routing protocol when used";
}
description
"This augments the IS-IS protocol LSDB TLV22.";
uses application-specific-link-attributes-sub-tlv;
}
/* TLV 223 */
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 augments the IS-IS routing protocol when used";
}
description
"This augments the IS-IS protocol LSDB TLV223.";
uses application-specific-link-attributes-sub-tlv;
}
/* Application-specific SRLG TLV 238 */
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol"
+ "/isis:isis/isis:database/isis:levels/isis:lsp" {
when "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type = 'isis:isis'" {
description
"This augments the IS-IS routing protocol when used";
}
description
"This augments the IS-IS protocol LSDB.";
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uses application-specific-srlg-tlv;
}
}
<CODE ENDS>
3. YANG Module for IS-IS Flexible Algorithm
This section defines the YANG module for IS-IS Flexible Algorithm.
The module uses the identities defined in the IANA-maintained YANG
modules for IGP Algorithm Types [IANA-IGP-Algo-Types] and IGP Metric
Type [IANA-IGP-Metric-Types] in [I-D.ietf-lsr-ospf-flex-algo-yang].
This YANG module references [RFC7308], [RFC8349], [RFC8776],
[RFC9130], [IANA-IGP-Algo-Types], and [IANA-IGP-Metric-Types].
module: ietf-isis-flex-algo
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/isis:isis:
+--rw isis-flex-algo
+--rw flex-algo* [algo-number]
+--rw algo-number uint8
+--rw advertise-definition? boolean
+--rw admin-groups {te-types:extended-admin-groups}?
| +--rw exclude-admin-group?
| | te-types:extended-admin-group
| +--rw include-any-admin-group?
| | te-types:extended-admin-group
| +--rw include-all-admin-group?
| te-types:extended-admin-group
+--rw exclude-srlg* te-types:srlg
+--rw metric-type? iana-metric-types:metric-type
+--rw calc-type? iana-algo-types:algo-type
+--rw prefix-metric!
+--rw priority? uint8
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 fad-tlvs
+--ro fad-tlv* []
+--ro algo-number? uint8
+--ro metric-type? iana-metric-types:metric-type
+--ro calc-type? iana-algo-types:algo-type
+--ro priority? uint8
+--ro fa-ex-ag-sub-tlv
| +--ro extended-admin-group?
| te-types:extended-admin-group
+--ro fa-in-any-ag-sub-tlv
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| +--ro extended-admin-group?
| te-types:extended-admin-group
+--ro fa-in-all-ag-sub-tlv
| +--ro extended-admin-group?
| te-types:extended-admin-group
+--ro fad-flags-sub-tlv
| +--ro fad-flag* identityref
+--ro fa-ex-srlg-sub-tlv
| +--ro srlg* te-types:srlg
+--ro unknown-tlvs
+--ro unknown-tlv* []
+--ro type? uint16
+--ro length? uint16
+--ro value? yang:hex-string
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 fapm-sub-tlvs
+--ro fapm-sub-tlv* []
+--ro algo-number? uint8
+--ro metric? 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 fapm-sub-tlvs
+--ro fapm-sub-tlv* []
+--ro algo-number? uint8
+--ro metric? 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 fapm-sub-tlvs
+--ro fapm-sub-tlv* []
+--ro algo-number? uint8
+--ro metric? 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 fapm-sub-tlvs
+--ro fapm-sub-tlv* []
+--ro algo-number? uint8
+--ro metric? uint32
notifications:
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+---n flex-algo-not-supported
+--ro routing-protocol-name? leafref
+--ro isis-level? level
+--ro algo-number? uint8
<CODE BEGINS> file "ietf-isis-flex-algo@2026-07-01.yang"
module ietf-isis-flex-algo {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-isis-flex-algo";
prefix isis-flex-algo;
import ietf-routing {
prefix rt;
reference
"RFC 8349: A YANG Data Model for Routing
Management (NMDA Version)";
}
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 iana-igp-algo-types {
prefix iana-algo-types;
reference
"IANA IGP Algorithm Types registry,
<https://www.iana.org/assignments/igp-parameters>.";
}
import iana-igp-metric-types {
prefix iana-metric-types;
reference
"IANA IGP Metric-Type registry,
<https://www.iana.org/assignments/igp-parameters>.";
}
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
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<mailto:yingzhen.ietf@gmail.com>
Author: Acee Lindem
<mailto:acee.ietf@gmail.com>
Author: Madhavi Joshi
<mailto:madhavi@arrcus.com>
";
description
"The YANG module defines the configuration and operational
state for IS-IS Flexible Algorithm as defined in RFC 9350.
Copyright (c) 2026 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).
All revisions of IETF and IANA published modules can be found
at the YANG Parameters registry group
(https://www.iana.org/assignments/yang-parameters).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
revision 2026-07-02 {
description
"Initial Version";
reference
"RFC XXXX: A YANG Data Model for IS-IS Application-Specific
Link Attributes and Flexible Algorithm";
}
/* Identities */
identity fad-flags {
description
"Base identity for IS-IS FAD flags.";
}
identity m-flag {
base fad-flags;
description
"M-flag in the Flex-Algorithm Definition (FAD) flags sub-TLV.
When this flag is present in the fad-flags leaf-list, the
Flex-Algorithm-specific prefix metric is used for inter-area
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and external prefix calculation. Note that this flag is not
applicable to prefixes advertised as SRv6 locators.";
reference
"RFC 9350: IGP Flexible Algorithm, Section 6.4";
}
/* Groupings */
grouping fa-ex-ag-sub-tlv {
container fa-ex-ag-sub-tlv {
leaf extended-admin-group {
type te-types:extended-admin-group;
description
"Extended administrative group value.";
reference
"RFC 7308: Extended Administrative Groups in MPLS-TE";
}
description
"The flex-algo exclude admin group sub-tlv. Note that the
presence of more than one Exclude Extended Admin Group
sub-TLV will result in an invalid FAD TLV.";
}
description
"The flex-algo exclude admin group sub-tlv.";
}
grouping fa-in-any-ag-sub-tlv {
container fa-in-any-ag-sub-tlv {
leaf extended-admin-group {
type te-types:extended-admin-group;
description
"Extended administrative group value.";
reference
"RFC 7308: Extended Administrative Groups in MPLS-TE";
}
description
"The flex-algo include-any admin group sub-tlv. Note that
the presence of more than one Include-Any Extended Admin
Group sub-TLV will result in an invalid FAD TLV.";
}
description
"The flex-algo include-any admin group sub-tlv.";
}
grouping fa-in-all-ag-sub-tlv {
container fa-in-all-ag-sub-tlv {
leaf extended-admin-group {
type te-types:extended-admin-group;
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description
"Extended administrative group value.";
reference
"RFC 7308: Extended Administrative Groups in MPLS-TE";
}
description
"The flex-algo include-all admin group sub-tlv. Note that
the presence of more than one Include-All Extended Admin
Group sub-TLV will result in an invalid FAD TLV.";
}
description
"The flex-algo include-all admin group sub-tlv.";
}
grouping fad-flags-sub-tlv {
container fad-flags-sub-tlv {
leaf-list fad-flag {
type identityref {
base fad-flags;
}
description
"Flex-algo definition flags list.";
}
description
"IS-IS flex-algo definition flags.";
}
description
"The flex-algo definition flags sub-tlv.";
}
grouping fa-ex-srlg-sub-tlv {
container fa-ex-srlg-sub-tlv {
leaf-list srlg {
type te-types:srlg;
description
"SRLG value as defined in RFC 4203.";
}
description
"The flex-algo exclude SRLG sub-tlv.";
}
description
"The flex-algo exclude SRLG sub-tlv.";
}
grouping fad-tlvs {
container fad-tlvs {
list fad-tlv {
leaf algo-number {
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type uint8;
description
"Flex-algo number - A value not in the inclusive range
of 128-255 is an invalid FAD TLV specification. Valid
Flex-Algorithm numbers are in the inclusive range
128-255 as specified in RFC 9350. There should only be
a single FAD TLV per algorithm number.";
reference
"RFC 9350: IGP Flexible Algorithm, Section 5";
}
leaf metric-type {
type iana-metric-types:metric-type;
description
"Type of metric to be used during the calculation.";
}
leaf calc-type {
type iana-algo-types:algo-type;
description
"IGP algorithm types, value from 0 to 127 as
defined under 'Interior Gateway Protocol (IGP)
Parameter' by IANA.";
}
leaf priority {
type uint8;
description
"Priority of the advertisement.";
}
uses fa-ex-ag-sub-tlv;
uses fa-in-any-ag-sub-tlv;
uses fa-in-all-ag-sub-tlv;
uses fad-flags-sub-tlv;
uses fa-ex-srlg-sub-tlv;
uses isis:unknown-tlvs;
description
"List of flex-algo definition TLVs.";
}
description
"IS-IS Flexible Algorithm Definition TLV.";
}
description
"IS-IS Flexible Algorithm Definition (FAD) TLV.";
}
grouping fapm-sub-tlvs {
container fapm-sub-tlvs {
list fapm-sub-tlv {
leaf algo-number {
type uint8;
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description
"Flex-algo number - A value not in the inclusive range
of 128-255 is an invalid FAPM sub-TLV specification.";
}
leaf metric {
type uint32;
description
"Prefix metric.";
}
description
"List of flex-algo prefix sub-tlvs.";
}
description
"Flex-algo prefix metric sub-tlvs.";
}
description
"Flexible Algorithm Prefix Metric (FAPM) sub TLVs.";
}
/* Management */
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol"
+ "/isis:isis" {
when "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type = 'isis:isis'" {
description
"This augments the IS-IS routing protocol when used";
}
description
"This augments the IS-IS protocol management
with flexible algorithm.";
container isis-flex-algo {
list flex-algo {
key "algo-number";
leaf algo-number {
type uint8 {
range "128..255";
}
description
"Flex-algo number - must be in the inclusive range
of 128-255.";
}
leaf advertise-definition {
type boolean;
default "true";
description
"When set to true, enables advertisement of the
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Flexible Algorithm Definition (FAD) TLV for this
flex-algo instance.";
}
container admin-groups {
if-feature "te-types:extended-admin-groups";
leaf exclude-admin-group {
type te-types:extended-admin-group;
description
"Exclude rule used during the flex-algo
path computation.";
}
leaf include-any-admin-group {
type te-types:extended-admin-group;
description
"Include-any rule used during the flex-algo
path computation.";
}
leaf include-all-admin-group {
type te-types:extended-admin-group;
description
"Include-all rule used during the flex-algo
path computation.";
}
description
"Specify adminstrative groups for the flex-algo
path computation.";
}
leaf-list exclude-srlg {
type te-types:srlg;
description
"Shared Risk Link Groups (SRLGs) to be excluded during
the flex-algo path computation.";
}
leaf metric-type {
type iana-metric-types:metric-type;
description
"Type of metric to be used during the calculation.";
}
leaf calc-type {
type iana-algo-types:algo-type;
description
"Calculation-type. Value from 0-127 inclusive from the
IANA 'IGP Algorithm Types' registry defined under the
'Interior Gateway Protocol (IGP) Parameters' registry.";
}
container prefix-metric {
presence "Use flex-algo specific prefix metric.";
description
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"Use flex-algo prefix metric.";
}
leaf priority {
type uint8;
description
"Priority of the advertisement.";
}
description
"List of flex-algo configurations.";
}
description
"Flexible Algorithm configuration.";
}
}
/* Database */
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 "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/"
+ "rt:type = 'isis:isis'" {
description
"This augments the IS-IS routing protocol when used";
}
description
"This augments the IS-IS protocol LSDB router capability.";
uses fad-tlvs;
}
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 "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/"
+ "rt:type = 'isis:isis'" {
description
"This augments the IS-IS routing protocol when used";
}
description
"This augments the IS-IS protocol LSDB prefix.";
uses fapm-sub-tlvs;
}
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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-extended-ipv4-reachability/isis:prefixes" {
when "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/"
+ "rt:type = 'isis:isis'" {
description
"This augments the IS-IS routing protocol when used";
}
description
"This augments the IS-IS protocol LSDB prefix.";
uses fapm-sub-tlvs;
}
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 "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/"
+ "rt:type = 'isis:isis'" {
description
"This augments the IS-IS routing protocol when used";
}
description
"This augments the IS-IS protocol LSDB prefix.";
uses fapm-sub-tlvs;
}
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 "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/"
+ "rt:type = 'isis:isis'" {
description
"This augments the IS-IS routing protocol when used";
}
description
"This augments the IS-IS protocol LSDB prefix.";
uses fapm-sub-tlvs;
}
/* Notification */
notification flex-algo-not-supported {
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uses isis:notification-instance-hdr;
leaf algo-number {
type uint8;
description
"Flex-algo identifier which is not supported by the IS-IS
instance. Valid Flex-Algorithm numbers are in the
inclusive range 128-255 as specified in RFC 9350.
A value outside this range in a received FAD TLV
is invalid.";
reference
"RFC 9350: IGP Flexible Algorithm, Section 5";
}
description
"This notification is sent when an IS-IS instance does not
support this flex-algo.";
}
}
<CODE ENDS>
4. Security Considerations
This section is modeled after the template described in Section 3.7.1
of [RFC9907].
The YANG modules defined in this document are designed to be accessed
via YANG-based management protocols, such as NETCONF [RFC6241] and
RESTCONF [RFC8040]. These protocols have to use a secure transport
layer (e.g., SSH [RFC4252], TLS [I-D.ietf-tls-rfc8446bis], and QUIC
[RFC9000]) and have to use mutual authentication.
The Network Configuration Access Control Model (NACM) [RFC8341]
provides the means to restrict access for particular NETCONF or
RESTCONF users to a preconfigured subset of all available NETCONF or
RESTCONF protocol operations and content.
There are a number of data nodes defined in this YANG module that are
writable/creatable/deletable (i.e., "config true", which is the
default). 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/isis-link-attr/link-attr-op-mode - Modification to the
protocol operation mode may result in traffic disruption.
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/isis:isis/isis:interfaces:isis:interface/isis-asla/interface-asla
- Modification to the configured ASLA interface attributes may
result in the disruption or rerouting of traffic.
/isis:isis/isis-flex-algo/flex-algo - Modification to flex-algo
configuration could be used to mount a DoS attack. For example,
changing of calc-type may result in routing loops.
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 exposure may facilitate other attacks.
Additionally, network operators may consider their topologies to be
sensitive confidential data.
The flex-algo-not-supported notification defined in this document may
reveal information about the local IS-IS instance's algorithm
capabilities. Access to this notification SHOULD be restricted using
NACM [RFC8341] to authorized management stations.
The YANG modules defined in this document do not include any RPC or
action operations. Hence, there are no security considerations
associated with these YANG constructs.
5. IANA Considerations
This document registers two URIs in the IETF XML registry [RFC3688].
Following the format in [RFC3688], the following registrations are
requested:
URI: urn:ietf:params:xml:ns:yang:ietf-isis-link-attr
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
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 [RFC7950].
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name: ietf-isis-link-attr
Maintained by IANA? N
namespace: urn:ietf:params:xml:ns:yang:ietf-isis-link-attr
prefix: isis-link-attr
reference: RFC XXXX
name: ietf-isis-flex-algo
Maintained by IANA? N
namespace: urn:ietf:params:xml:ns:yang:ietf-isis-flex-algo
prefix: isis-flex-algo
reference: RFC XXXX
6. Acknowledgements
Thanks to Michal Vasko for his YANG doctors review.
Thanks to Adrian Farrel for his OPS directorate review.
Thanks to Renato Westphal for review and comments.
Thanks to Eric Vyncke, Mike Bishop, and Ketan Talauikar for comments.
Thanks to Med Boucadair and Mahesh Jethanandani for extensive review
and comments.
7. References
7.1. Normative References
[I-D.ietf-lsr-ospf-flex-algo-yang]
Qu, Y. and A. Lindem, "YANG Data Model for OSPF
Application-Specific Link Attributes and Flexible
Algorithm", Work in Progress, Internet-Draft, draft-ietf-
lsr-ospf-flex-algo-yang-08, 3 May 2026,
<https://datatracker.ietf.org/doc/html/draft-ietf-lsr-
ospf-flex-algo-yang-08>.
[IANA-IGP-Algo-Types]
IANA, "IGP Algorithm Types",
<https://www.iana.org/assignments/igp-parameters>.
[IANA-IGP-Metric-Types]
IANA, "IGP Metric-Type",
<https://www.iana.org/assignments/igp-parameters>.
[IANA-Link-Attr-Apps]
IANA, "Link Attribute Application Identifiers",
<https://www.iana.org/assignments/igp-parameters>.
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[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>.
[RFC5305] Li, T. and H. Smit, "IS-IS Extensions for Traffic
Engineering", RFC 5305, DOI 10.17487/RFC5305, October
2008, <https://www.rfc-editor.org/info/rfc5305>.
[RFC5307] Kompella, K., Ed. and Y. Rekhter, Ed., "IS-IS Extensions
in Support of Generalized Multi-Protocol Label Switching
(GMPLS)", RFC 5307, DOI 10.17487/RFC5307, October 2008,
<https://www.rfc-editor.org/info/rfc5307>.
[RFC7308] Osborne, E., "Extended Administrative Groups in MPLS
Traffic Engineering (MPLS-TE)", RFC 7308,
DOI 10.17487/RFC7308, July 2014,
<https://www.rfc-editor.org/info/rfc7308>.
[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>.
[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>.
[RFC8294] Liu, X., Qu, Y., Lindem, A., Hopps, C., and L. Berger,
"Common YANG Data Types for the Routing Area", RFC 8294,
DOI 10.17487/RFC8294, December 2017,
<https://www.rfc-editor.org/info/rfc8294>.
[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>.
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[RFC8776] Saad, T., Gandhi, R., Liu, X., Beeram, V., and I. Bryskin,
"Common YANG Data Types for Traffic Engineering",
RFC 8776, DOI 10.17487/RFC8776, June 2020,
<https://www.rfc-editor.org/info/rfc8776>.
[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>.
[RFC9350] Psenak, P., Ed., Hegde, S., Filsfils, C., Talaulikar, K.,
and A. Gulko, "IGP Flexible Algorithm", RFC 9350,
DOI 10.17487/RFC9350, February 2023,
<https://www.rfc-editor.org/info/rfc9350>.
[RFC9479] Ginsberg, L., Psenak, P., Previdi, S., Henderickx, W., and
J. Drake, "IS-IS Application-Specific Link Attributes",
RFC 9479, DOI 10.17487/RFC9479, October 2023,
<https://www.rfc-editor.org/info/rfc9479>.
[RFC9911] Schönwälder, J., Ed., "Common YANG Data Types", RFC 9911,
DOI 10.17487/RFC9911, December 2025,
<https://www.rfc-editor.org/info/rfc9911>.
7.2. Informative References
[I-D.ietf-tls-rfc8446bis]
Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", Work in Progress, Internet-Draft, draft-
ietf-tls-rfc8446bis-14, 13 September 2025,
<https://datatracker.ietf.org/doc/html/draft-ietf-tls-
rfc8446bis-14>.
[RFC4252] Ylonen, T. and C. Lonvick, Ed., "The Secure Shell (SSH)
Authentication Protocol", RFC 4252, DOI 10.17487/RFC4252,
January 2006, <https://www.rfc-editor.org/info/rfc4252>.
[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>.
[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>.
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[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>.
[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,
<https://www.rfc-editor.org/info/rfc8792>.
[RFC9000] Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based
Multiplexed and Secure Transport", RFC 9000,
DOI 10.17487/RFC9000, May 2021,
<https://www.rfc-editor.org/info/rfc9000>.
[RFC9907] Bierman, A., Boucadair, M., Ed., and Q. Wu, "Guidelines
for Authors and Reviewers of Documents Containing YANG
Data Models", BCP 216, RFC 9907, DOI 10.17487/RFC9907,
March 2026, <https://www.rfc-editor.org/info/rfc9907>.
Appendix A. Example IS-IS Flex-Algo Configuration
The following is an example configuration for IS-IS Flexible
Algorithm using the YANG model defined in this document.
Note: '\' line wrapping per [RFC8792].
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<?xml version='1.0' encoding='UTF-8'?>
<routing xmlns="urn:ietf:params:xml:ns:yang:ietf-routing">
<router-id>1.1.1.1</router-id>
<control-plane-protocols>
<control-plane-protocol>
<type xmlns:isis="urn:ietf:params:xml:ns:yang:ietf-isis">\
isis:isis</type>
<name>isis</name>
<isis xmlns="urn:ietf:params:xml:ns:yang:ietf-isis">
<system-id>1111.2222.3333</system-id>
<area-address>49.0001.0000.0000.0001</area-address>
<isis-flex-algo xmlns="urn:ietf:params:xml:ns:yang:\
ietf-isis-flex-algo">
<flex-algo>
<algo-number>200</algo-number>
<admin-groups>
<exclude-admin-group>aa</exclude-admin-group>
</admin-groups>
<metric-type xmlns:iana-metric-types="urn:ietf:params:\
xml:ns:yang:iana-igp-metric-types">igp-metric\
</metric-type>
<calc-type xmlns:iana-algo-types="urn:ietf:params:\
xml:ns:yang:iana-igp-algo-types">algo-spf</calc-type>
<prefix-metric/>
<priority>100</priority>
</flex-algo>
</isis-flex-algo>
</isis>
</control-plane-protocol>
</control-plane-protocols>
</routing>
Appendix B. Example IS-IS Flex-Algo Configuration (JSON)
The following is an example configuration for IS-IS Flexible
Algorithm in JSON format using the YANG module defined in this
document.
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{
"ietf-routing:routing": {
"router-id": "1.1.1.1",
"control-plane-protocols": {
"control-plane-protocol": [
{
"type": "ietf-isis:isis",
"name": "isis",
"ietf-isis:isis": {
"system-id": "1111.2222.3333",
"area-address": [
"49.0001.0000.0000.0001"
],
"ietf-isis-flex-algo:isis-flex-algo": {
"flex-algo": [
{
"algo-number": 200,
"admin-groups": {
"exclude-admin-group": "aa"
},
"metric-type": "igp-metric",
"calc-type": "algo-spf",
"prefix-metric": {},
"priority": 100
}
]
}
}
}
]
}
}
}
Authors' Addresses
Yingzhen Qu
Futurewei Technologies
United States of America
Email: yingzhen.ietf@gmail.com
Acee Lindem
Arrcus, Inc.
United States of America
Email: acee.ietf@gmail.com
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Madhavi Joshi
Arrcus, Inc.
United States of America
Email: madhavi@arrcus.com
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