| Internet-Draft | OSPF ASLA and Flex-Algo YANG | July 2026 |
| Qu & Lindem | Expires 4 January 2027 | [Page] |
This document defines a YANG data model to support OSPF Application-Specific Link Attributes and Flexible Algorithm. It also creates the initial version of IANA-maintained YANG modules for IGP Algorithm Types, IGP Metric-Types, and IGP Link Attribute Applications.¶
This document updates RFCs 8665, 9350, and 9843.¶
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 4 January 2027.¶
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.¶
This document defines YANG [RFC7950] data modules augmenting the IETF OSPF YANG model [RFC9129], which itself augments the IETF Routing model [RFC8349], to provide support for both OSPF Flexible Algorithm as defined in [RFC9350] and OSPF Application-Specific Link Attributes as defined in [RFC9492].¶
There are three IANA-maintained YANG modules defined in this document as well. The first is the initial version of the IANA-maintained YANG module for IGP Algorithm Types. The second module is the initial version of the IANA-maintained YANG module for IGP Metric-Type. The third module is the initial version of the IANA-maintained YANG module for IGP Link Attribute Application types.¶
This document updates [RFC8665], [RFC9350], and [RFC9843].¶
The meanings of the symbols in the YANG tree diagrams are defined in [RFC8340].¶
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.¶
This document defined a YANG module for OSPF Application-Specific Link Attributes (ASLA) as defined in [RFC9492].¶
The module augments OSPF router configuration with support for the ASLA operation mode, enabling interoperability during the transition from legacy advertisements to ASLA. In addition, both OSPFv2 and OSPFv3 LSAs are augmented to include the TLVs defined in[RFC9492].¶
As far as whether or not an application-specific link attribute is included, only legacy attributes that are defined in [RFC9129] are included. Additional attributes will be included in these TLVs when the augmentations for the corresponding legacy attributes are added.¶
This YANG module references [RFC8349], [RFC9129], [RFC9350], [RFC9492], and [RFC9587] .¶
module: ietf-ospf-link-attr
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf:
+--rw ospf-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/ospf:ospf/ospf:areas/ospf:area
/ospf:interfaces/ospf:interface:
+--rw ospf-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
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:areas/ospf:area
/ospf:database/ospf:area-scope-lsa-type
/ospf:area-scope-lsas/ospf:area-scope-lsa/ospf:version
/ospf:ospfv2/ospf:ospfv2/ospf:body/ospf:opaque
/ospf:extended-link-opaque/ospf:extended-link-tlv:
+--ro app-specific-link-attr-sub-tlvs
+--ro asla-sub-tlv* []
+--ro sabm
| +--ro sabm-bit* iana-link-attr-apps:igp-link-attr-app
+--ro udabm
+--ro link-attributes-sub-tlvs
+--ro te-metric? te-types:te-metric
+--ro admin-group? te-types:admin-group
+--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/ospf:ospf/ospf:areas/ospf:area
/ospf:database/ospf:area-scope-lsa-type
/ospf:area-scope-lsas/ospf:area-scope-lsa/ospf:version
/ospf:ospfv3/ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-router
/ospfv3-e-lsa:e-router-tlvs/ospfv3-e-lsa:link-tlv:
+--ro app-specific-link-attr-sub-tlvs
+--ro asla-sub-tlv* []
+--ro sabm
| +--ro sabm-bit* iana-link-attr-apps:igp-link-attr-app
+--ro udabm
+--ro link-attributes-sub-tlvs
+--ro te-metric? te-types:te-metric
+--ro admin-group? te-types:admin-group
+--ro unknown-tlvs
+--ro unknown-tlv* []
+--ro type? uint16
+--ro length? uint16
+--ro value? yang:hex-string
¶
<CODE BEGINS> file "ietf-ospf-link-attr@2026-07-04.yang"
module ietf-ospf-flex-algo {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-ospf-flex-algo";
prefix ospf-flex-algo;
import ietf-routing {
prefix rt;
reference
"RFC 8349: A YANG Data Model for Routing
Management (NMDA Version)";
}
import ietf-routing-types {
prefix rt-types;
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 ietf-ospf {
prefix ospf;
reference
"RFC 9129: YANG Data Model for the OSPF
Protocol";
}
import ietf-ospfv3-extended-lsa {
prefix ospfv3-e-lsa;
reference
"RFC 9587: YANG Data Model for OSPFv3 Extended Link
State Advertisements (LSAs)";
}
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
<mailto:yingzhen.ietf@gmail.com>
Author: Acee Lindem
<mailto:acee.ietf@gmail.com>
";
description
"The YANG module defines the configuration and operational
state for OSPF 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.
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 2026-07-04 {
description
"Initial Version";
reference
"RFC XXXX: A YANG Data Model for OSPF Application-Specific
Link Attributes and Flexible Algorithm";
}
/* Identities */
identity fad-flags {
description
"Base identity for OSPF FAD flags.";
reference
"RFC 9350: IGP Flexible Algorithm, Section 7";
}
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
and external prefix calculation. Note that this flag is not
applicable to prefixes advertised as SRv6 locators.";
reference
"RFC 9350: IGP Flexible Algorithm, Section 7.4";
}
identity fapm-flags {
description
"Base identity for OSPF flex-algo prefix metric flags.";
reference
"RFC 9350: IGP Flexible Algorithm";
}
identity e-bit {
base fapm-flags;
description
"External metric, if set, the metric specified is a
type 2 external metric.";
reference
"RFC 9350: IGP Flexible Algorithm";
}
/* Groupings */
grouping fad-tlvs {
container fad-tlvs {
list fad-tlv {
leaf algo-number {
type uint8;
description
"Flex-algo number - A value not in the inclusive range
of 128-255 is an invalid FAD TLV specification. There
should only be a single FAD TLV per algorithm number.";
}
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.";
}
container fa-ex-ag-sub-tlv {
leaf extended-admin-group {
type te-types:extended-admin-group;
description
"Extended administrative group as defined in
RFC 7308.";
}
description
"The flex-algo exclude admin group sub-tlv.";
}
container fa-in-any-ag-sub-tlv {
leaf extended-admin-group {
type te-types:extended-admin-group;
description
"Extended administrative group as defined in
RFC 7308.";
}
description
"The flex-algo include-any admin group sub-tlv.";
}
container fa-in-all-ag-sub-tlv {
leaf extended-admin-group {
type te-types:extended-admin-group;
description
"Extended administrative group as defined in
RFC 7308.";
}
description
"The flex-algo include-all admin group sub-tlv.";
}
container fad-flags-sub-tlv {
leaf-list fad-flag {
type identityref {
base fad-flags;
}
description
"Flex-algo definition flags list.";
}
description
"OSPF flex-algo definition flags.";
}
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.";
}
uses ospf:unknown-tlvs;
description
"List of flex-algo definition TLVs.";
}
description
"OSPF Flexible Algorithm Definition TLV.";
}
description
"OSPF Flexible Algorithm Definition (FAD) TLV.";
reference
"RFC 9350: IGP Flexible Algorithm";
}
grouping fapm-sub-tlvs {
container fapm-sub-tlvs {
list fapm-sub-tlv {
leaf algo-number {
type uint8;
description
"Flex-algo number - A value not in the inclusive range
of 128-255 is an invalid FAD TLV specification.";
}
leaf-list fapm-flag {
type identityref {
base fapm-flags;
}
description
"Flex-algo prefix metric flags list.";
}
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.";
reference
"RFC 9350: IGP Flexible Algorithm";
}
grouping faam-sub-tlvs {
container faam-sub-tlvs {
list faam-sub-tlv {
leaf algo-number {
type uint8;
description
"Flex-algo number - A value not in the inclusive range
of 128-255 is an invalid FAAM Sub-TLV specification.";
}
leaf metric {
type uint32;
description
"Prefix metric.";
}
description
"List of faam sub-tlvs.";
}
description
"Flexible Algorithm ASBR Metric (FAAM) Sub-TLVs.";
}
description
"Flexible Algorithm ASBR Metric (FAAM) Sub-TLVs.";
reference
"RFC 9350: IGP Flexible Algorithm";
}
/* Management */
augment "/rt:routing/rt:control-plane-protocols"
+ "/rt:control-plane-protocol/ospf:ospf" {
when "../rt:type = 'ospf:ospfv2' or "
+ "../rt:type = 'ospf:ospfv3'" {
description
"This augments the OSPF routing protocol when used.";
}
description
"This augments OSPF protocol with Flexible
Algorithm.";
container ospf-flex-algo {
list flex-algo {
key "algo-number";
leaf algo-number {
type uint8 {
range "128..255";
}
description
"An identifier associated with the Flexible Algorithm
Definition.";
}
leaf advertise-definition {
type boolean;
default "true";
description
"Enable to advertise the flex-algo definition.";
}
container admin-groups {
if-feature "te-types:named-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
"The flex-algo include-any admin group. Note that the
presence of more than one Include-Any Extended Admin
Group will result in an invalid FAD TLV.";
}
leaf include-all-admin-group {
type te-types:extended-admin-group;
description
"The flex-algo include-all admin group. Note that the
presence of more than one Include-All Extended Admin
Group will result in an invalid FAD TLV.";
}
description
"Specify links 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 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.";
}
leaf metric-type {
type iana-metric-types:metric-type;
description
"Type of metric to be used during the calculation.";
}
container prefix-metric {
presence "Use flex-algo specific prefix metric.";
description
"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/"
+ "ospf:ospf/ospf:areas/ospf:area/"
+ "ospf:interfaces/ospf:interface/ospf:database/"
+ "ospf:link-scope-lsa-type/ospf:link-scope-lsas/"
+ "ospf:link-scope-lsa/ospf:version/ospf:ospfv2/"
+ "ospf:ospfv2/ospf:body/ospf:opaque/ospf:ri-opaque" {
when "../../../../../../../../../../../../../"
+ "rt:type = 'ospf:ospfv2'" {
description
"This augmentation is only valid for OSPFv2.";
}
description
"Flex-algo definition TLVs for OSPFv2 type 9 opaque RI LSA.";
uses fad-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/"
+ "ospf:area/ospf:database/"
+ "ospf:area-scope-lsa-type/ospf:area-scope-lsas/"
+ "ospf:area-scope-lsa/ospf:version/ospf:ospfv2/"
+ "ospf:ospfv2/ospf:body/ospf:opaque/ospf:ri-opaque" {
when "../../../../../../../../../../../"
+ "rt:type = 'ospf:ospfv2'" {
description
"This augmentation is only valid for OSPFv2.";
}
description
"Flex-algo definition TLVs for OSPFv2 type 10 opaque RI LSA.";
uses fad-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:database/"
+ "ospf:as-scope-lsa-type/ospf:as-scope-lsas/"
+ "ospf:as-scope-lsa/ospf:version/ospf:ospfv2/"
+ "ospf:ospfv2/ospf:body/ospf:opaque/ospf:ri-opaque" {
when "../../../../../../../../../"
+ "rt:type = 'ospf:ospfv2'" {
description
"This augmentation is only valid for OSPFv2.";
}
description
"Flex-algo definition TLVs for OSPFv2 type 11 opaque RI LSA.";
uses fad-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/ospf:area/"
+ "ospf:interfaces/ospf:interface/ospf:database/"
+ "ospf:link-scope-lsa-type/ospf:link-scope-lsas/"
+ "ospf:link-scope-lsa/ospf:version/ospf:ospfv3/"
+ "ospf:ospfv3/ospf:body/ospf:router-information" {
when "../../../../../../../../../../../../"
+ "rt:type = 'ospf:ospfv3'" {
description
"This augmentation is only valid for OSPFv3.";
}
description
"Flex-algo definition TLVs for OSPFv3 Router
Information (RI) LSA.";
uses fad-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/"
+ "ospf:area/ospf:database/"
+ "ospf:area-scope-lsa-type/ospf:area-scope-lsas/"
+ "ospf:area-scope-lsa/ospf:version/ospf:ospfv3/"
+ "ospf:ospfv3/ospf:body/ospf:router-information" {
when "../../../../../../../../../../"
+ "rt:type = 'ospf:ospfv3'" {
description
"This augmentation is only valid for OSPFv3.";
}
description
"Flex-algo definition TLVs for OSPFv3 Router
Information (RI) LSA.";
uses fad-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:database/"
+ "ospf:as-scope-lsa-type/ospf:as-scope-lsas/"
+ "ospf:as-scope-lsa/ospf:version/ospf:ospfv3/"
+ "ospf:ospfv3/ospf:body/ospf:router-information" {
when "../../../../../../../../"
+ "rt:type = 'ospf:ospfv3'" {
description
"This augmentation is only valid for OSPFv3.";
}
description
"Flex-algo definition TLVs for OSPFv3 Router Information LSA.";
uses fad-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/ospf:area/"
+ "ospf:interfaces/ospf:interface/ospf:database/"
+ "ospf:link-scope-lsa-type/ospf:link-scope-lsas/"
+ "ospf:link-scope-lsa/ospf:version/ospf:ospfv2/"
+ "ospf:ospfv2/ospf:body/ospf:opaque/"
+ "ospf:extended-prefix-opaque/ospf:extended-prefix-tlv" {
when "../../../../../../../../../../../../../../"
+ "rt:type = 'ospf:ospfv2'" {
description
"This augmentation is only valid for OSPFv2.";
}
description
"Flex-algo prefix metric sub-TLVs for OSPFv2 extended
prefix TLV in type 9 opaque LSA.";
uses fapm-sub-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/"
+ "ospf:area/ospf:database/"
+ "ospf:area-scope-lsa-type/ospf:area-scope-lsas/"
+ "ospf:area-scope-lsa/ospf:version/ospf:ospfv2/"
+ "ospf:ospfv2/ospf:body/ospf:opaque/"
+ "ospf:extended-prefix-opaque/ospf:extended-prefix-tlv" {
when "../../../../../../../../../../../../"
+ "rt:type = 'ospf:ospfv2'" {
description
"This augmentation is only valid for OSPFv2.";
}
description
"Flex-algo prefix metric sub-TLVs for OSPFv2 extended
prefix TLV in type 10 opaque LSA.";
uses fapm-sub-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:database/"
+ "ospf:as-scope-lsa-type/ospf:as-scope-lsas/"
+ "ospf:as-scope-lsa/ospf:version/ospf:ospfv2/"
+ "ospf:ospfv2/ospf:body/ospf:opaque/"
+ "ospf:extended-prefix-opaque/"
+ "ospf:extended-prefix-tlv" {
when "../../../../../../../../../../"
+ "rt:type = 'ospf:ospfv2'" {
description
"This augmentation is only valid for OSPFv2.";
}
description
"Flex-algo prefix metric sub-TLVs for OSPFv2 extended
prefix TLV in type 11 opaque LSA.";
uses fapm-sub-tlvs;
}
/* Flex-algo prefix metric Sub-TLV in OSPFv3 Inter-Area
Prefix TLV */
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/ospf:area/ospf:database/"
+ "ospf:area-scope-lsa-type/ospf:area-scope-lsas/"
+ "ospf:area-scope-lsa/ospf:version/ospf:ospfv3/"
+ "ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-inter-area-prefix/"
+ "ospfv3-e-lsa:e-inter-prefix-tlvs/"
+ "ospfv3-e-lsa:inter-prefix-tlv" {
when "../../../../../../../../../../../../"
+ "rt:type = 'ospf:ospfv3'" {
description
"This augmentation is only valid for OSPFv3
E-Router LSAs";
}
uses fapm-sub-tlvs;
description
"OSPFv3 Area-Scoped Inter-Area Prefix TLV.";
}
/* Flex-algo prefix metric Sub-TLV in OSPFv3 External Prefix TLV */
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:database/"
+ "ospf:as-scope-lsa-type/ospf:as-scope-lsas/"
+ "ospf:as-scope-lsa/ospf:version/ospf:ospfv3/"
+ "ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-as-external/"
+ "ospfv3-e-lsa:e-external-tlvs/"
+ "ospfv3-e-lsa:external-prefix-tlv" {
when "../../../../../../../../../../"
+ "rt:type = 'ospf:ospfv3'" {
description
"This augmentation is only valid for OSPFv3.";
}
uses fapm-sub-tlvs;
description
"OSPFv3 AS-Scoped External Prefix TLV.";
}
/* OSPFv2 Extended Inter-Area ASBR LSA */
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/"
+ "ospf:area/ospf:database/"
+ "ospf:area-scope-lsa-type/ospf:area-scope-lsas/"
+ "ospf:area-scope-lsa/ospf:version/ospf:ospfv2/"
+ "ospf:ospfv2/ospf:body/ospf:opaque" {
when "../../../../../../../../../../"
+ "rt:type = 'ospf:ospfv2'" {
description
"This augmentation is only valid for OSPFv2.";
}
description
"OSPFv2 Extended Inter-Area ASBR LSA in type 10
opaque LSA.";
container eia-asbr-opaque {
container eia-asbr-tlv {
leaf asbr-rtr-id {
type rt-types:router-id;
description
"The OSPF Router ID of the ASBR.";
}
uses faam-sub-tlvs;
uses ospf:unknown-tlvs;
description
"EIA-ASBR TLV, used to advertise additional attributes
associated with the reachability of an ASBR.";
}
uses ospf:unknown-tlvs;
description
"OSPFv2 Extended Inter-Area (EIA-ASBR) opaque LSA.";
}
}
/* FAAM Sub-TLV in OSPFv3 Inter-Area-Router TLV */
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/ospf:area/ospf:database/"
+ "ospf:area-scope-lsa-type/ospf:area-scope-lsas/"
+ "ospf:area-scope-lsa/ospf:version/ospf:ospfv3/"
+ "ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-inter-area-router/"
+ "ospfv3-e-lsa:e-inter-router-tlvs/"
+ "ospfv3-e-lsa:inter-router-tlv" {
when "../../../../../../../../../../../../"
+ "rt:type = 'ospf:ospfv3'" {
description
"This augmentation is only valid for OSPFv3
Inter-Area-Router TLV.";
}
uses faam-sub-tlvs;
description
"OSPFv3 Area-Scoped Inter-Area-Router TLV.";
}
/* Notification */
notification flex-algo-not-supported {
leaf routing-protocol-name {
type leafref {
path "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:name";
}
description
"Name of the OSPF instance.";
}
leaf algo-number {
type uint8;
description
"Flex-algo identifier which is not supported by the OSPF
instance. A value not in the inclusive range of 128-255
is indicative of an invalid FAD algorithm specification.";
}
description
"This notification is sent when an OSPF instance does not
support this flex-algo.";
}
}
<CODE ENDS>¶
This document defines a YANG module for OSPF Flexible Algorithm as defined in [RFC9350]. It is an augmentation of the OSPF base model.¶
The module augments OSPF router configuration with support flexible algorithms. In addition, both the OSPFv2 and OSPFv3 link-state databases are augmented to include the TLVs defined in[RFC9350].¶
This YANG module references [RFC8349], [RFC9129], [RFC9350], [RFC9587], and [I-D.ietf-teas-yang-te].¶
module: ietf-ospf-flex-algo
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf:
+--rw ospf-flex-algo
+--rw flex-algo* [algo-number]
+--rw algo-number uint8
+--rw advertise-definition? boolean
+--rw admin-groups
| {te-types:named-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 calc-type? iana-algo-types:algo-type
+--rw metric-type?
| iana-metric-types:metric-type
+--rw prefix-metric!
+--rw priority? uint8
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:areas
/ospf:area/ospf:interfaces/ospf:interface
/ospf:database/ospf:link-scope-lsa-type
/ospf:link-scope-lsas/ospf:link-scope-lsa/ospf:version
/ospf:ospfv2/ospf:ospfv2/ospf:body/ospf:opaque
/ospf:ri-opaque:
+--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
| +--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/ospf:ospf/ospf:areas
/ospf:area/ospf:database/ospf:area-scope-lsa-type
/ospf:area-scope-lsas/ospf:area-scope-lsa/ospf:version
/ospf:ospfv2/ospf:ospfv2/ospf:body/ospf:opaque
/ospf:ri-opaque:
+--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
| +--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/ospf:ospf/ospf:database
/ospf:as-scope-lsa-type/ospf:as-scope-lsas
/ospf:as-scope-lsa/ospf:version/ospf:ospfv2
/ospf:ospfv2/ospf:body/ospf:opaque/ospf:ri-opaque:
+--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
| +--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/ospf:ospf/ospf:areas
/ospf:area/ospf:interfaces/ospf:interface
/ospf:database/ospf:link-scope-lsa-type
/ospf:link-scope-lsas/ospf:link-scope-lsa/ospf:version
/ospf:ospfv3/ospf:ospfv3/ospf:body
/ospf:router-information:
+--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
| +--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/ospf:ospf/ospf:areas
/ospf:area/ospf:database/ospf:area-scope-lsa-type
/ospf:area-scope-lsas/ospf:area-scope-lsa/ospf:version
/ospf:ospfv3/ospf:ospfv3/ospf:body
/ospf:router-information:
+--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
| +--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/ospf:ospf/ospf:database
/ospf:as-scope-lsa-type/ospf:as-scope-lsas
/ospf:as-scope-lsa/ospf:version/ospf:ospfv3
/ospf:ospfv3/ospf:body/ospf:router-information:
+--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
| +--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/ospf:ospf/ospf:areas
/ospf:area/ospf:interfaces/ospf:interface
/ospf:database/ospf:link-scope-lsa-type
/ospf:link-scope-lsas/ospf:link-scope-lsa/ospf:version
/ospf:ospfv2/ospf:ospfv2/ospf:body/ospf:opaque
/ospf:extended-prefix-opaque/ospf:extended-prefix-tlv:
+--ro fapm-sub-tlvs
+--ro fapm-sub-tlv* []
+--ro algo-number? uint8
+--ro fapm-flag* identityref
+--ro metric? uint32
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:areas
/ospf:area/ospf:database/ospf:area-scope-lsa-type
/ospf:area-scope-lsas/ospf:area-scope-lsa/ospf:version
/ospf:ospfv2/ospf:ospfv2/ospf:body/ospf:opaque
/ospf:extended-prefix-opaque/ospf:extended-prefix-tlv:
+--ro fapm-sub-tlvs
+--ro fapm-sub-tlv* []
+--ro algo-number? uint8
+--ro fapm-flag* identityref
+--ro metric? uint32
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:database
/ospf:as-scope-lsa-type/ospf:as-scope-lsas
/ospf:as-scope-lsa/ospf:version/ospf:ospfv2
/ospf:ospfv2/ospf:body/ospf:opaque
/ospf:extended-prefix-opaque/ospf:extended-prefix-tlv:
+--ro fapm-sub-tlvs
+--ro fapm-sub-tlv* []
+--ro algo-number? uint8
+--ro fapm-flag* identityref
+--ro metric? uint32
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:areas
/ospf:area/ospf:database/ospf:area-scope-lsa-type
/ospf:area-scope-lsas/ospf:area-scope-lsa/ospf:version
/ospf:ospfv3/ospf:ospfv3/ospf:body
/ospfv3-e-lsa:e-inter-area-prefix
/ospfv3-e-lsa:e-inter-prefix-tlvs
/ospfv3-e-lsa:inter-prefix-tlv:
+--ro fapm-sub-tlvs
+--ro fapm-sub-tlv* []
+--ro algo-number? uint8
+--ro fapm-flag* identityref
+--ro metric? uint32
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:database
/ospf:as-scope-lsa-type/ospf:as-scope-lsas
/ospf:as-scope-lsa/ospf:version/ospf:ospfv3
/ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-as-external
/ospfv3-e-lsa:e-external-tlvs
/ospfv3-e-lsa:external-prefix-tlv:
+--ro fapm-sub-tlvs
+--ro fapm-sub-tlv* []
+--ro algo-number? uint8
+--ro fapm-flag* identityref
+--ro metric? uint32
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:areas
/ospf:area/ospf:database/ospf:area-scope-lsa-type
/ospf:area-scope-lsas/ospf:area-scope-lsa/ospf:version
/ospf:ospfv2/ospf:ospfv2/ospf:body/ospf:opaque:
+--ro eia-asbr-opaque
+--ro eia-asbr-tlv
| +--ro asbr-rtr-id? rt-types:router-id
| +--ro faam-sub-tlvs
| | +--ro faam-sub-tlv* []
| | +--ro algo-number? uint8
| | +--ro metric? uint32
| +--ro unknown-tlvs
| +--ro unknown-tlv* []
| +--ro type? uint16
| +--ro length? uint16
| +--ro value? yang:hex-string
+--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/ospf:ospf/ospf:areas
/ospf:area/ospf:database/ospf:area-scope-lsa-type
/ospf:area-scope-lsas/ospf:area-scope-lsa/ospf:version
/ospf:ospfv3/ospf:ospfv3/ospf:body
/ospfv3-e-lsa:e-inter-area-router
/ospfv3-e-lsa:e-inter-router-tlvs
/ospfv3-e-lsa:inter-router-tlv:
+--ro faam-sub-tlvs
+--ro faam-sub-tlv* []
+--ro algo-number? uint8
+--ro metric? uint32
notifications:
+---n flex-algo-not-supported
+--ro routing-protocol-name? leafref
+--ro algo-number? uint8
¶
<CODE BEGINS> file "ietf-ospf-flex-algo@2026-07-02.yang"
module ietf-ospf-flex-algo {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-ospf-flex-algo";
prefix ospf-flex-algo;
import ietf-routing {
prefix rt;
reference
"RFC 8349: A YANG Data Model for Routing
Management (NMDA Version)";
}
import ietf-routing-types {
prefix rt-types;
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 ietf-ospf {
prefix ospf;
reference
"RFC 9129: YANG Data Model for the OSPF
Protocol";
}
import ietf-ospfv3-extended-lsa {
prefix ospfv3-e-lsa;
reference
"RFC 9587: YANG Data Model for OSPFv3 Extended Link
State Advertisements (LSAs)";
}
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-type;
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
<mailto:yingzhen.ietf@gmail.com>
Author: Acee Lindem
<mailto:acee.ietf@gmail.com>
";
description
"The YANG module defines the configuration and operational
state for OSPF 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.
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 OSPF Application-Specific
Link Attributes and Flexible Algorithm";
}
/* Identities */
identity fad-flags {
description
"Base identity for OSPF FAD flags.";
reference
"RFC 9350: IGP Flexible Algorithm, Section 7";
}
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
and external prefix calculation. Note that this flag is not
applicable to prefixes advertised as SRv6 locators.";
reference
"RFC 9350: IGP Flexible Algorithm, Section 7.4";
}
identity fapm-flags {
description
"Base identity for OSPF flex-algo prefix metric flags.";
reference
"RFC 9350: IGP Flexible Algorithm";
}
identity e-bit {
base fapm-flags;
description
"External metric, if set, the metric specified is a
type 2 external metric.";
reference
"RFC 9350: IGP Flexible Algorithm";
}
/* Groupings */
grouping fad-tlvs {
container fad-tlvs {
list fad-tlv {
leaf algo-number {
type uint8;
description
"Flex-algo number - A value not in the inclusive range
of 128-255 is an invalid FAD TLV specification. There
should only be a single FAD TLV per algorithm number.";
}
leaf metric-type {
type iana-metric-type: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.";
}
container fa-ex-ag-sub-tlv {
leaf extended-admin-group {
type te-types:extended-admin-group;
description
"Extended administrative group as defined in
RFC 7308.";
}
description
"The flex-algo exclude admin group sub-tlv.";
}
container fa-in-any-ag-sub-tlv {
leaf extended-admin-group {
type te-types:extended-admin-group;
description
"Extended administrative group as defined in
RFC 7308.";
}
description
"The flex-algo include-any admin group sub-tlv.";
}
container fa-in-all-ag-sub-tlv {
leaf extended-admin-group {
type te-types:extended-admin-group;
description
"Extended administrative group as defined in
RFC 7308.";
}
description
"The flex-algo include-all admin group sub-tlv.";
}
container fad-flags-sub-tlv {
leaf-list fad-flag {
type identityref {
base fad-flags;
}
description
"Flex-algo definition flags list.";
}
description
"OSPF flex-algo definition flags.";
}
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.";
}
uses ospf:unknown-tlvs;
description
"List of flex-algo definition TLVs.";
}
description
"OSPF Flexible Algorithm Definition TLV.";
}
description
"OSPF Flexible Algorithm Definition (FAD) TLV.";
reference
"RFC 9350: IGP Flexible Algorithm";
}
grouping fapm-sub-tlvs {
container fapm-sub-tlvs {
list fapm-sub-tlv {
leaf algo-number {
type uint8;
description
"Flex-algo number - A value not in the inclusive range
of 128-255 is an invalid FAD TLV specification.";
}
leaf-list fapm-flag {
type identityref {
base fapm-flags;
}
description
"Flex-algo prefix metric flags list.";
}
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.";
reference
"RFC 9350: IGP Flexible Algorithm";
}
grouping faam-sub-tlvs {
container faam-sub-tlvs {
list faam-sub-tlv {
leaf algo-number {
type uint8;
description
"Flex-algo number - A value not in the inclusive range
of 128-255 is an invalid FAAM Sub-TLV specification.";
}
leaf metric {
type uint32;
description
"Prefix metric.";
}
description
"List of faam sub-tlvs.";
}
description
"Flexible Algorithm ASBR Metric (FAAM) Sub-TLVs.";
}
description
"Flexible Algorithm ASBR Metric (FAAM) Sub-TLVs.";
reference
"RFC 9350: IGP Flexible Algorithm";
}
/* Management */
augment "/rt:routing/rt:control-plane-protocols"
+ "/rt:control-plane-protocol/ospf:ospf" {
when "../rt:type = 'ospf:ospfv2' or "
+ "../rt:type = 'ospf:ospfv3'" {
description
"This augments the OSPF routing protocol when used.";
}
description
"This augments OSPF protocol with Flexible
Algorithm.";
container ospf-flex-algo {
list flex-algo {
key "algo-number";
leaf algo-number {
type uint8 {
range "128..255";
}
description
"An identifier associated with the Flexible Algorithm
Definition.";
}
leaf advertise-definition {
type boolean;
default "true";
description
"Enable to advertise the flex-algo definition.";
}
container admin-groups {
if-feature "te-types:named-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
"The flex-algo include-any admin group. Note that the
presence of more than one Include-Any Extended Admin
Group will result in an invalid FAD TLV.";
}
leaf include-all-admin-group {
type te-types:extended-admin-group;
description
"The flex-algo include-all admin group. Note that the
presence of more than one Include-All Extended Admin
Group will result in an invalid FAD TLV.";
}
description
"Specify links 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 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.";
}
leaf metric-type {
type iana-metric-type:metric-type;
description
"Type of metric to be used during the calculation.";
}
container prefix-metric {
presence "Use flex-algo specific prefix metric.";
description
"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/"
+ "ospf:ospf/ospf:areas/ospf:area/"
+ "ospf:interfaces/ospf:interface/ospf:database/"
+ "ospf:link-scope-lsa-type/ospf:link-scope-lsas/"
+ "ospf:link-scope-lsa/ospf:version/ospf:ospfv2/"
+ "ospf:ospfv2/ospf:body/ospf:opaque/ospf:ri-opaque" {
when "../../../../../../../../../../../../../"
+ "rt:type = 'ospf:ospfv2'" {
description
"This augmentation is only valid for OSPFv2.";
}
description
"Flex-algo definition TLVs for OSPFv2 type 9 opaque RI LSA.";
uses fad-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/"
+ "ospf:area/ospf:database/"
+ "ospf:area-scope-lsa-type/ospf:area-scope-lsas/"
+ "ospf:area-scope-lsa/ospf:version/ospf:ospfv2/"
+ "ospf:ospfv2/ospf:body/ospf:opaque/ospf:ri-opaque" {
when "../../../../../../../../../../../"
+ "rt:type = 'ospf:ospfv2'" {
description
"This augmentation is only valid for OSPFv2.";
}
description
"Flex-algo definition TLVs for OSPFv2 type 10 opaque RI LSA.";
uses fad-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:database/"
+ "ospf:as-scope-lsa-type/ospf:as-scope-lsas/"
+ "ospf:as-scope-lsa/ospf:version/ospf:ospfv2/"
+ "ospf:ospfv2/ospf:body/ospf:opaque/ospf:ri-opaque" {
when "../../../../../../../../../"
+ "rt:type = 'ospf:ospfv2'" {
description
"This augmentation is only valid for OSPFv2.";
}
description
"Flex-algo definition TLVs for OSPFv2 type 11 opaque RI LSA.";
uses fad-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/ospf:area/"
+ "ospf:interfaces/ospf:interface/ospf:database/"
+ "ospf:link-scope-lsa-type/ospf:link-scope-lsas/"
+ "ospf:link-scope-lsa/ospf:version/ospf:ospfv3/"
+ "ospf:ospfv3/ospf:body/ospf:router-information" {
when "../../../../../../../../../../../../"
+ "rt:type = 'ospf:ospfv3'" {
description
"This augmentation is only valid for OSPFv3.";
}
description
"Flex-algo definition TLVs for OSPFv3 Router
Information (RI) LSA.";
uses fad-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/"
+ "ospf:area/ospf:database/"
+ "ospf:area-scope-lsa-type/ospf:area-scope-lsas/"
+ "ospf:area-scope-lsa/ospf:version/ospf:ospfv3/"
+ "ospf:ospfv3/ospf:body/ospf:router-information" {
when "../../../../../../../../../../"
+ "rt:type = 'ospf:ospfv3'" {
description
"This augmentation is only valid for OSPFv3.";
}
description
"Flex-algo definition TLVs for OSPFv3 Router
Information (RI) LSA.";
uses fad-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:database/"
+ "ospf:as-scope-lsa-type/ospf:as-scope-lsas/"
+ "ospf:as-scope-lsa/ospf:version/ospf:ospfv3/"
+ "ospf:ospfv3/ospf:body/ospf:router-information" {
when "../../../../../../../../"
+ "rt:type = 'ospf:ospfv3'" {
description
"This augmentation is only valid for OSPFv3.";
}
description
"Flex-algo definition TLVs for OSPFv3 Router Information LSA.";
uses fad-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/ospf:area/"
+ "ospf:interfaces/ospf:interface/ospf:database/"
+ "ospf:link-scope-lsa-type/ospf:link-scope-lsas/"
+ "ospf:link-scope-lsa/ospf:version/ospf:ospfv2/"
+ "ospf:ospfv2/ospf:body/ospf:opaque/"
+ "ospf:extended-prefix-opaque/ospf:extended-prefix-tlv" {
when "../../../../../../../../../../../../../../"
+ "rt:type = 'ospf:ospfv2'" {
description
"This augmentation is only valid for OSPFv2.";
}
description
"Flex-algo prefix metric sub-TLVs for OSPFv2 extended
prefix TLV in type 9 opaque LSA.";
uses fapm-sub-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/"
+ "ospf:area/ospf:database/"
+ "ospf:area-scope-lsa-type/ospf:area-scope-lsas/"
+ "ospf:area-scope-lsa/ospf:version/ospf:ospfv2/"
+ "ospf:ospfv2/ospf:body/ospf:opaque/"
+ "ospf:extended-prefix-opaque/ospf:extended-prefix-tlv" {
when "../../../../../../../../../../../../"
+ "rt:type = 'ospf:ospfv2'" {
description
"This augmentation is only valid for OSPFv2.";
}
description
"Flex-algo prefix metric sub-TLVs for OSPFv2 extended
prefix TLV in type 10 opaque LSA.";
uses fapm-sub-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:database/"
+ "ospf:as-scope-lsa-type/ospf:as-scope-lsas/"
+ "ospf:as-scope-lsa/ospf:version/ospf:ospfv2/"
+ "ospf:ospfv2/ospf:body/ospf:opaque/"
+ "ospf:extended-prefix-opaque/"
+ "ospf:extended-prefix-tlv" {
when "../../../../../../../../../../"
+ "rt:type = 'ospf:ospfv2'" {
description
"This augmentation is only valid for OSPFv2.";
}
description
"Flex-algo prefix metric sub-TLVs for OSPFv2 extended
prefix TLV in type 11 opaque LSA.";
uses fapm-sub-tlvs;
}
/* Flex-algo prefix metric Sub-TLV in OSPFv3 Inter-Area
Prefix TLV */
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/ospf:area/ospf:database/"
+ "ospf:area-scope-lsa-type/ospf:area-scope-lsas/"
+ "ospf:area-scope-lsa/ospf:version/ospf:ospfv3/"
+ "ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-inter-area-prefix/"
+ "ospfv3-e-lsa:e-inter-prefix-tlvs/"
+ "ospfv3-e-lsa:inter-prefix-tlv" {
when "../../../../../../../../../../../../"
+ "rt:type = 'ospf:ospfv3'" {
description
"This augmentation is only valid for OSPFv3
E-Router LSAs";
}
uses fapm-sub-tlvs;
description
"OSPFv3 Area-Scoped Inter-Area Prefix TLV.";
}
/* Flex-algo prefix metric Sub-TLV in OSPFv3 External Prefix TLV */
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:database/"
+ "ospf:as-scope-lsa-type/ospf:as-scope-lsas/"
+ "ospf:as-scope-lsa/ospf:version/ospf:ospfv3/"
+ "ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-as-external/"
+ "ospfv3-e-lsa:e-external-tlvs/"
+ "ospfv3-e-lsa:external-prefix-tlv" {
when "../../../../../../../../../../"
+ "rt:type = 'ospf:ospfv3'" {
description
"This augmentation is only valid for OSPFv3.";
}
uses fapm-sub-tlvs;
description
"OSPFv3 AS-Scoped External Prefix TLV.";
}
/* OSPFv2 Extended Inter-Area ASBR LSA */
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/"
+ "ospf:area/ospf:database/"
+ "ospf:area-scope-lsa-type/ospf:area-scope-lsas/"
+ "ospf:area-scope-lsa/ospf:version/ospf:ospfv2/"
+ "ospf:ospfv2/ospf:body/ospf:opaque" {
when "../../../../../../../../../../"
+ "rt:type = 'ospf:ospfv2'" {
description
"This augmentation is only valid for OSPFv2.";
}
description
"OSPFv2 Extended Inter-Area ASBR LSA in type 10
opaque LSA.";
container eia-asbr-opaque {
container eia-asbr-tlv {
leaf asbr-rtr-id {
type rt-types:router-id;
description
"The OSPF Router ID of the ASBR.";
}
uses faam-sub-tlvs;
uses ospf:unknown-tlvs;
description
"EIA-ASBR TLV, used to advertise additional attributes
associated with the reachability of an ASBR.";
}
uses ospf:unknown-tlvs;
description
"OSPFv2 Extended Inter-Area (EIA-ASBR) opaque LSA.";
}
}
/* FAAM Sub-TLV in OSPFv3 Inter-Area-Router TLV */
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/ospf:area/ospf:database/"
+ "ospf:area-scope-lsa-type/ospf:area-scope-lsas/"
+ "ospf:area-scope-lsa/ospf:version/ospf:ospfv3/"
+ "ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-inter-area-router/"
+ "ospfv3-e-lsa:e-inter-router-tlvs/"
+ "ospfv3-e-lsa:inter-router-tlv" {
when "../../../../../../../../../../../../"
+ "rt:type = 'ospf:ospfv3'" {
description
"This augmentation is only valid for OSPFv3
Inter-Area-Router TLV.";
}
uses faam-sub-tlvs;
description
"OSPFv3 Area-Scoped Inter-Area-Router TLV.";
}
/* Notification */
notification flex-algo-not-supported {
leaf routing-protocol-name {
type leafref {
path "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:name";
}
description
"Name of the OSPF instance.";
}
leaf algo-number {
type uint8;
description
"Flex-algo identifier which is not supported by the OSPF
instance. A value not in the inclusive range of 128-255
is indicative of an invalid FAD algorithm specification.";
}
description
"This notification is sent when an OSPF instance does not
support this flex-algo.";
}
}
<CODE ENDS>¶
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:¶
Some of the readable data nodes in this YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control read access (e.g., via get, get-config, or notification) to these data nodes. Specifically, the following subtrees and data nodes have particular sensitivities/ vulnerabilities:¶
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.¶
This document registers URIs in the IETF XML registry [RFC3688]. Following the format in [RFC3688], the following registrations are requested to be made:¶
URI: urn:ietf:params:xml:ns:yang:iana-igp-algo-types Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace.¶
URI: urn:ietf:params:xml:ns:yang:iana-igp-metric-types Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace.¶
URI: urn:ietf:params:xml:ns:yang:iana-igp-link-attr-apps Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace.¶
URI: urn:ietf:params:xml:ns:yang:ietf-ospf-link-attr Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace.¶
URI: urn:ietf:params:xml:ns:yang:ietf-ospf-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 [RFC6020].¶
name: iana-igp-algo-types Maintained by IANA? Y namespace: urn:ietf:params:xml:ns:yang:iana-igp-algo-types prefix: iana-algo-types reference: RFC XXXX¶
name: iana-igp-metric-types Maintained by IANA? Y namespace: urn:ietf:params:xml:ns:yang:iana-igp-metric-types prefix: iana-metric-types reference: RFC XXXX¶
name: iana-igp-link-attr-apps Maintained by IANA? Y namespace: urn:ietf:params:xml:ns:yang:iana-igp-link-attr-apps prefix: iana-link-attr-app reference: RFC XXXX¶
name: ietf-ospf-link-attr Maintained by IANA? N namespace: urn:ietf:params:xml:ns:yang:ietf-ospf-link-attr prefix: ospf-link-attr reference: RFC XXXX¶
name: ietf-ospf-flex-algo Maintained by IANA? N namespace: urn:ietf:params:xml:ns:yang:ietf-ospf-flex-algo prefix: ospf-flex-algo reference: RFC XXXX¶
IANA is requested to add a "Name" column to the "IGP Algorithm Types" registry. The values for the "Name" column for existing Algorithm Types are:¶
| Value | Name | Description | Reference |
|---|---|---|---|
| 0 | SPF | Shortest Path First (SPF) algorithm based on link metric. This is the standard shortest path algorithm as computed by the IGP protocol. Consistent with the deployed practice for link-state protocols, Algorithm 0 permits any node to overwrite the SPF path with a different path based on its local policy. | [RFC8665] |
| 1 | Strict SPF | Strict Shortest Path First (SPF) algorithm based on link metric. The algorithm is identical to Algorithm 0 but Algorithm 1 requires that all nodes along the path will honor the SPF routing decision. Local policy at the node claiming support for Algorithm 1 MUST NOT alter the SPF paths computed by Algorithm 1. | [RFC8665] |
IANA is requested to add a "Name" column to the "IGP Metric-Type" registry. The values for the "Name" column for existing Algorithm Types are:¶
| Type | Name | Description | Reference | Allowed in Generic-Metric |
|---|---|---|---|---|
| 0 | IGP Metric | IGP Metric | [RFC9350], Section 5.1 | No |
| 1 | Min Unidirectional Link Delay | Min Unidirectional Link Delay as defined in [RFC8570], Section 4.2 and [RFC7471], Section 4.2 | [RFC9350], Section 5.1 | No |
| 2 | TE Default Metric | Traffic Engineering Default Metric as defined in [RFC5305], Section 3.7 and Traffic Engineering Metric as defined in [RFC3630], Section 2.5.5 | [RFC9350], Section 5.1 | No |
| 3 | Bandwidth Metric | Bandwidth Metric | [RFC9843], Section 5.1 | Yes |
| 128-255 | Reserved | Reserved for User-Defined Metric | [RFC9843], Section 5.1 | Yes |
This document creates the initial version of the IANA-maintained "iana-igp-algo-types" YANG module. The most recent version of the YANG module is available from the "YANG Parameters" registry [IANA-YANG-Parameters].¶
IANA is requested to add this note to the registry:¶
New values must not be directly added to the "iana-algo-types" YANG module. They must instead be added to the "IGP Algorithm Types" registry in the "Interior Gateway Protocol (IGP) Parameters" registry group.¶
IANA is requested to add this note to [IANA-IGP-ALGO-Types]:¶
When this registry is modified, the YANG module "iana-igp-algo-types" [IANA-YANG-Parameters] must be updated as defined in RFC XXXX.¶
When a value is added to the "IGP Algorithm Types" registry, a new "enum" statement needs to be added to the "iana-igp-algo-types" YANG module. The name of the "enum" is a lowercase version of the name as provided in the registry with spaces replaced with hyphens, i.e., "-"s, and beginning with "algo-". The "enum" statement should have the following sub-statements defined:¶
"value": Contains the decimal value of the IANA-assigned
value.
"description": Replicates the description from the registry.
"reference": Replicates the reference(s) from the registry
with the title of the document(s) added.
¶
This document creates the initial version of the IANA-maintained "iana-igp-metric-types" YANG module. The most recent version of the YANG module is available from the "YANG Parameters" registry [IANA-YANG-Parameters].¶
IANA is requested to add this note to the registry:¶
New values must not be directly added to the "iana-igp-metric-types" YANG module. They must instead be added to the "IGP Metric-Type" registry in the "Interior Gateway Protocol (IGP) Parameters" registry group.¶
IANA is requested to add this note to [IANA-IGP-Metric-Types]:¶
When this registry is modified, the YANG module "iana-metric-types" [IANA-YANG-Parameters] must be updated as defined in RFC XXXX.¶
When a value is added to the "IGP Metric-Type" registry, a new "enum" statement needs to be added to the "iana-igp-metric-types" YANG module. The name of the "enum" is a lowercase version of the name as provided in the registry with the spaces replaced with hyphens, i.e., "-"s. The "enum" statement should have the following sub-statements defined:¶
"value": Contains the decimal value of the IANA-assigned
value.
"description": Replicates the description from the registry.
"reference": Replicates the reference(s) from the registry
with the title of the document(s) added.
¶
This document creates the initial version of the IANA-maintained "iana-igp-link-attr-apps" YANG module. The most recent version of the YANG module is available from the "YANG Parameters" registry [IANA-YANG-Parameters].¶
IANA is requested to add this note to the registry:¶
New values must not be directly added to the "iana-igp-link-attr-apps" YANG module. They must instead be added to the "Link Attribute Application Identifiers" registry in the "Interior Gateway Protocol (IGP) Parameters" registry group.¶
IANA is requested to add this note to [IANA-Link-Attr-Apps]:¶
When this registry is modified, the YANG module "iana-igp-link-attr-apps" [IANA-YANG-Parameters] must be updated as defined in RFC XXXX .¶
When a value is added to the "Link Attribute Application Identifiers" registry, a new "enum" statement needs to be added to the "iana-igp-link-attr-apps" YANG module. The name of the "enum" is a lowercase version of the Name field as provided in the registry with spaces replaced with hyphens, i.e., "-"s. and ending with "-app". In order to form the YANG "enum", the name of the application is taken from the beginning the registry description, not including text in parenthesis. The "enum" statement should have the following sub-statements defined:¶
"value": Contains the decimal value of the IANA-assigned
value.
"description": Replicates the Name text when a new value
is added.
"reference": Replicates the reference(s) from the registry
with the title of the document(s) added.
¶
Thanks to Dhruv Dhody for his detailed YANG doctors review.¶
Thanks to Adrian Farrel for his OPS directorate review.¶
Thanks to Renato Westphal for his review and comments.¶
Thanks to Med Boucadair and Mahesh Jethanandani for extensive review and comments.¶
The following is an example configuration for OSPF Flexible Algorithm using the YANG model defined in this document.¶
Note: '\' line wrapping per [RFC8792].¶
<?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:ospf="urn:ietf:params:xml:ns:yang:ietf-ospf">\
ospf:ospfv2</type>
<name>OSPFv2</name>
<ospf xmlns="urn:ietf:params:xml:ns:yang:ietf-ospf">
<areas>
<area>
<area-id>0.0.0.0</area-id>
</area>
</areas>
<ospf-flex-algo xmlns="urn:ietf:params:xml:ns:yang:\
ietf-ospf-flex-algo">
<flex-algo>
<algo-number>200</algo-number>
<admin-groups>
<exclude-admin-group>AA:BB</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>
</ospf-flex-algo>
</ospf>
</control-plane-protocol>
</control-plane-protocols>
</routing>
¶
The following is the same example configuration for OSPF Flexible Algorithm as in the previous section in JSON format using the YANG model defined in this document.¶
{
"ietf-routing:routing": {
"router-id": "1.1.1.1",
"control-plane-protocols": {
"control-plane-protocol": [
{
"type": "ietf-ospf:ospfv2",
"name": "OSPFv2",
"ietf-ospf:ospf": {
"areas": {
"area": [
{
"area-id": "0.0.0.0"
}
]
},
"ietf-ospf-flex-algo:ospf-flex-algo": {
"flex-algo": [
{
"algo-number": 200,
"admin-groups": {
"exclude-admin-group": "AA:BB"
},
"calc-type": "algo-spf",
"metric-type": "igp-metric",
"prefix-metric": {},
"priority": 100
}
]
}
}
}
]
}
}
}
¶
//RFC Editor: please remove the Appendix C before publication and replace XXXX with the RFC number that is assigned to the document.¶
IANA has created a registry titled "IGP Algorithm Types" under the "Interior Gateway Protocol (IGP) Parameters" registry group to identify Algorithm Types. Module iana-igp-algo-types is an IANA-maintained module, which defines the identities for the Algorithm Types as in the IANA "IGP Algorithm Types" registry.¶
This document defines the initial version of the IANA-maintained YANG module for Algorithm Types that mirrors the IANA "IGP Algorithm Types" registry [IANA-IGP-ALGO-Types].¶
This YANG module references [RFC8665].¶
<CODE BEGINS> file "iana-igp-algo-types@2026-07-02.yang"
module iana-igp-algo-types {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:iana-igp-algo-types";
prefix iana-algo-types;
organization
"Internet Assigned Numbers Authority (IANA)";
contact
"Internet Assigned Numbers Authority
ICANN
12025 Waterfront Drive, Suite 300
Los Angeles, CA 90094-2536
United States of America
Tel: +1 310 301 5800
<mailto:iana@iana.org>";
description
"The YANG module defines the YANG data types for IANA-registered
Interior Gateway Protocol (IGP) Algorithm Types.
This YANG module is maintained by IANA and reflects the 'IGP
Algorithm Types' registry.
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 initial 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.
//RFC Ed.: replace XXXX with actual RFC number and remove
this note
The latest version of this YANG module is available at
https://www.iana.org/assignments/yang-parameters.
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
"Interior Gateway Protocol (IGP) Parameters, IGP Algorithm Types
(https://www.iana.org/assignments/igp-parameters/
igp-parameters.xhtml#igp-algorithm-types)";
revision 2026-07-02 {
description
"Initial Version";
reference
"RFC XXXX: YANG Data Model for OSPF Application-Specific
Link Attributes and Flexible Algorithm";
}
typedef algo-type {
type enumeration {
enum algo-spf {
value 0;
description
"Shortest Path First (SPF) algorithm based on link metric.
This is the standard shortest path algorithm as computed by
the IGP protocol. Consistent with the deployed practice for
link-state protocols, Algorithm 0 permits any node to
overwrite the SPF path with a different path based on its
local policy.";
reference
"RFC 8665: OSPF Extensions for Segment Routing";
}
enum algo-strict-spf {
value 1;
description
"Strict Shortest Path First (SPF) algorithm based on
link metric. The algorithm is identical to Algorithm 0 but
Algorithm 1 requires that all nodes along the path will
honor the SPF routing decision. Local policy at the node
claiming support for Algorithm 1 MUST NOT alter the SPF
paths computed by Algorithm 1.";
reference
"RFC 8665: OSPF Extensions for Segment Routing";
}
}
default "algo-spf";
description
"IGP Algorithm Type. The algorithm types are defined in IANA
IGP Algorithm Types registry";
}
}
<CODE ENDS>¶
//RFC Editor: please remove the Appendix D before publication and replace XXXX with the RFC number that is assigned to the document.¶
IANA has created a registry titled "IGP Metric-Type" under the "Interior Gateway Protocol (IGP) Parameters" registry group to identify Metric Types. Module iana-igp-metric-types is an IANA-maintained module, which defines the identities for the Metric Types as in the IANA "IGP Metric-Type" registry.¶
This document defines the initial version of the IANA-maintained YANG module for IGP metric types that mirrors the IANA "IGP Metric-Type" registry [IANA-IGP-Metric-Types].¶
This YANG module references [RFC3630], [RFC5305], [RFC7471], [RFC8570], [RFC9350], and [RFC9843].¶
<CODE BEGINS> file "iana-igp-metric-types@2026-07-02.yang"
module iana-igp-metric-types {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:iana-igp-metric-types";
prefix iana-metric-types;
organization
"Internet Assigned Numbers Authority (IANA)";
contact
"Internet Assigned Numbers Authority
ICANN
12025 Waterfront Drive, Suite 300
Los Angeles, CA 90094-2536
United States of America
Tel: +1 310 301 5800
<mailto:iana@iana.org>";
description
"The YANG module defines the YANG data types for IANA-registered
Interior Gateway Protocol (IGP) Metric-Types.
This YANG module is maintained by IANA and reflects the 'IGP
Metric-Type' registry.
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 initial 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.
//RFC Ed.: replace XXXX with actual RFC number and remove
this note
The latest version of this YANG module is available at
https://www.iana.org/assignments/yang-parameters.";
reference
"Interior Gateway Protocol (IGP) Parameters, IGP Algorithm Types
(https://www.iana.org/assignments/igp-parameters/
igp-parameters.xhtml#igp-metric-type)";
revision 2026-07-02 {
description
"Initial Version";
reference
"RFC XXXX: A YANG Data Model for OSPF Application-Specific
Link Attributes and Flexible Algorithm";
}
typedef metric-type {
type enumeration {
enum igp-metric {
value 0;
description
"IGP Metric.";
reference
"RFC9350: IGP Flexible Algorithm, Section 5.1";
}
enum min-unidirectional-link-delay {
value 1;
description
"Min Unidirectional Link Delay as defined in RFC 8570
and RFC 7471 Section 4.2.";
reference
"RFC 9350: IGP Flexible Algorithm, Section 5.1";
}
enum te-default-metric {
value 2;
description
"Traffic Engineering Default Metric as defined in RFC 5305
Section 3.7 and Traffic Engineering Metric as defined in
RFC3630, Section 2.5.5.";
reference
"RFC 9350: IGP Flexible Algorithm, Section 5.1";
}
enum bandwidth-metric {
value 3;
description
"Bandwidth metric.";
reference
"RFC 9843: IGP Flexible Algorithms: Bandwidth, Delay,
Metrics, and Constraints";
}
}
default "igp-metric";
description
"IGP Metric-Type. The metric types
are defined in IANA IGP Metric-Type registry.";
}
}
<CODE ENDS>¶
//RFC Editor: please remove the Appendix E before publication and replace XXXX with the RFC number that is assigned to the document.¶
IANA has created a registry titled "Link Attribute Application Identifiers" under the "Interior Gateway Protocol (IGP) Parameters" registry group to identify IGP application types with application-specific link attributes. Module iana-igp-link-attr-apps is an IANA-maintained module, which defines the identities for the link attribute application IDs as in the IANA "Link Attribute Application Identifiers" registry.¶
This document defines the initial version of the IANA-maintained YANG module for IGP application types that mirrors the IANA "Link Attribute Application Identifiers" registry [IANA-Link-Attr-Apps].¶
This YANG module references [RFC9492].¶
<CODE BEGINS> file "iana-igp-link-attr-apps@2026-07-02.yang"
module iana-igp-link-attr-apps {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:iana-igp-link-attr-apps";
prefix iana-link-attr-apps;
organization
"Internet Assigned Numbers Authority (IANA)";
contact
"Internet Assigned Numbers Authority
ICANN
12025 Waterfront Drive, Suite 300
Los Angeles, CA 90094-2536
United States of America
Tel: +1 310 301 5800
<mailto:iana@iana.org>";
description
"The YANG module defines the YANG data types for IANA-registered
Interior Gateway Protocol (IGP) Application IDs used for Link
Attributes.
This YANG module is maintained by IANA and reflects the 'Link
Attribute Application Identifiers' registry.
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 initial 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.
//RFC Ed.: replace XXXX with actual RFC number and remove
this note
The latest version of this YANG module is available at
https://www.iana.org/assignments/yang-parameters.";
reference
"Interior Gateway Protocol (IGP) Parameters, IGP Algorithm Types
(https://www.iana.org/assignments/igp-parameters/
igp-parameters.xhtml#link-attribute-application-identifiers)";
revision 2026-07-02 {
description
"Initial Version";
reference
"RFC XXXX: YANG Data Model for OSPF Application-Specific
Link Attributes and Flexible Algorithm";
}
typedef igp-link-attr-app {
type enumeration {
enum rsvp-te-app {
value 0;
description
"RSVP-TE (R-bit).";
reference
"RFC 9479: IS-IS Application-Specific Link Attributes";
}
enum segment-routing-policy-app {
value 1;
description
"Segment Routing Policy (S-bit).";
reference
"RFC 9479: IS-IS Application-Specific Link Attributes";
}
enum loop-free-alternate-app {
value 2;
description
"Loop-Free Alternate (F-bit).";
reference
"RFC 9479: IS-IS Application-Specific Link Attributes";
}
enum flexible-algorithm-app {
value 3;
description
"Flexible Algorithm (X-bit).";
reference
"RFC 9350: IGP Flexible Algorithm, Section 12.";
}
}
description
"Application IDs used for Link Attributes, which are defined
in the IANA Link Attribute Application Identifiers registry.";
reference
"RFC 9479: IS-IS Application-Specific Link Attributes";
}
}
<CODE ENDS>¶