RFC 9587
YANG Data Model for OSPFv3 Extended Link State Advertisements (LSAs)
Internet Engineering Task Force (IETF) 🌸
YANG Data Model for OSPFv3 Extended Link State Advertisements (LSAs) ✨
okay bestie, here's the whole vibe at a glance 💖
- RFC number: RFC 9587
- Authors: A. Lindem (LabN Consulting, L.L.C.), S. Palani (Microsoft), and Y. Qu (Futurewei Technologies)
- Category: Standards Track
- ISSN: 2070-1721
- Date: June 2024
- Obsoletes / Updates: the header has no Obsoletes or Updates line, so this doc doesn't list any 🙈
Abstract
okay so this doc defines a YANG data model that augments the IETF OSPF YANG data model (RFC 9129) 🧚 its whole job is adding support for OSPFv3 Link State Advertisement (LSA) Extensibility, which is defined in RFC 8362. the big idea is that OSPFv3 Extended LSAs give you extensible, TLV-based LSAs for the base LSA types from RFC 5340. it's giving modular and I'm obsessed 😭✨
Status of This Memo
this is an Internet Standards Track document 🎀
it's a product of the Internet Engineering Task Force (IETF), and it represents the consensus of the IETF community. it got public review and was approved for publication by the Internet Engineering Steering Group (IESG). if you want more on Internet Standards, check out Section 2 of RFC 7841 💅
for the current status, any errata, and how to send feedback, head to https://www.rfc-editor.org/info/rfc9587 🦋
Copyright Notice
Copyright (c) 2024 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) as they're in effect on the date of publication. please actually read these, bestie, because they spell out your rights and restrictions for this document 📜
if you pull Code Components out of this document, they must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions. they come without warranty, as described in the Revised BSD License ⚠️
Table of Contents 🧚
1. Overview
2. Tree Diagrams
3. OSPFv3 Extended LSAs
4. OSPFv3 Extended LSA YANG Module
5. Security Considerations
6. IANA Considerations
7. References
7.1. Normative References
7.2. Informative References
Appendix A. Configuration Example
Acknowledgements
Authors' Addresses1. Overview 💖
okay so YANG [RFC7950] is a data definition language. it defines the contents of a conceptual datastore, which lets networked devices be managed using NETCONF [RFC6241] 🫶 YANG is way beyond its original lane now, because bindings for other interfaces (like RESTCONF [RFC8040]) and encodings other than XML (like JSON) are getting defined. YANG data models can also be the foundation for other interfaces, like Command-Line Interfaces (CLIs) and programmatic APIs. it's literally everywhere 🔥
this document defines a YANG data model that augments the IETF OSPF YANG data model [RFC9129]. that one augments [RFC8349] itself. the goal is to support configuration and operational state for OSPFv3 Extended Link State Advertisements (LSAs) as defined in [RFC8362] ✨
the YANG module in this document conforms to the Network Management Datastore Architecture (NMDA) [RFC8342] 👑
2. Tree Diagrams 🌸
this document uses the graphical representation of data models defined in [RFC8340]. it's giving diagrams, and I'm here for it 🦋
3. OSPFv3 Extended LSAs ✨
okay so this section is where OSPFv3 Extended LSAs get real 💅 This doc defines a YANG data model for the OSPFv3 Extended LSA feature. It's an augmentation of the OSPF base model [RFC9129] that adds support for OSPFv3 LSA Extensibility [RFC8362]. Extended LSAs give you extensible, TLV-based LSAs for the base LSA types defined in [RFC5340] 🦋
the OSPFv3 Extended LSA YANG module needs support for the OSPF base model, which handles basic OSPF configuration and state 🌸 The OSPF YANG model augments the "ietf-routing" module from [RFC8349]. The augmentations in the "ietf-ospfv3-extended-lsa" module bring in global config, area config, and the Extended LSAs added to the Link State Database (LSDB) operational state. it's giving organized 🧚
here's the tree, bestie 🌈
module: ietf-ospfv3-extended-lsa
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf:
+--rw extended-lsa-support? boolean
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:areas
/ospf:area:
+--rw extended-lsa-support? boolean
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:
+--ro e-link
+--ro rtr-priority? uint8
+--ro lsa-options
| +--ro lsa-options* identityref
+--ro e-link-tlvs* []
+--ro unknown-tlv
| +--ro type? uint16
| +--ro length? uint16
| +--ro value? yang:hex-string
+--ro intra-prefix-tlv
| +--ro metric? ospf:ospf-metric
| +--ro prefix? inet:ip-prefix
| +--ro prefix-options
| | +--ro prefix-options* identityref
| +--ro sub-tlvs* []
| +--ro unknown-sub-tlv
| +--ro type? uint16
| +--ro length? uint16
| +--ro value? yang:hex-string
+--ro ipv6-link-local-addr-tlv
| +--ro link-local-address? inet:ipv6-address
| +--ro sub-tlvs* []
| +--ro unknown-sub-tlv
| +--ro type? uint16
| +--ro length? uint16
| +--ro value? yang:hex-string
+--ro ipv4-link-local-addr-tlv
+--ro link-local-address? inet:ipv4-address
+--ro sub-tlvs* []
+--ro unknown-sub-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:
+--ro e-router
| +--ro router-bits
| | +--ro rtr-lsa-bits* identityref
| +--ro lsa-options
| | +--ro lsa-options* identityref
| +--ro e-router-tlvs* []
| +--ro unknown-tlv
| | +--ro type? uint16
| | +--ro length? uint16
| | +--ro value? yang:hex-string
| +--ro link-tlv
| +--ro interface-id? uint32
| +--ro neighbor-interface-id? uint32
| +--ro neighbor-router-id? rt-types:router-id
| +--ro type? ospf:router-link-type
| +--ro metric? ospf:ospf-link-metric
| +--ro sub-tlvs* []
| +--ro unknown-sub-tlv
| +--ro type? uint16
| +--ro length? uint16
| +--ro value? yang:hex-string
+--ro e-network
| +--ro lsa-options
| | +--ro lsa-options* identityref
| +--ro e-network-tlvs* []
| +--ro unknown-tlv
| | +--ro type? uint16
| | +--ro length? uint16
| | +--ro value? yang:hex-string
| +--ro attached-router-tlv
| +--ro adjacent-neighbor-router-id* rt-types:router-id
+--ro e-nssa
| +--ro e-external-tlvs* []
| +--ro unknown-tlv
| | +--ro type? uint16
| | +--ro length? uint16
| | +--ro value? yang:hex-string
| +--ro external-prefix-tlv
| +--ro flags
| | +--ro ospfv3-e-external-prefix-bits* identityref
| +--ro metric? ospf:ospf-metric
| +--ro prefix? inet:ip-prefix
| +--ro prefix-options
| | +--ro prefix-options* identityref
| +--ro sub-tlvs* []
| +--ro ipv6-fwd-addr-sub-tlv
| | +--ro forwarding-address? inet:ipv6-address
| +--ro ipv4-fwd-addr-sub-tlv
| | +--ro forwarding-address? inet:ipv4-address
| +--ro route-tag-sub-tlv
| | +--ro route-tag? uint32
| +--ro unknown-sub-tlv
| +--ro type? uint16
| +--ro length? uint16
| +--ro value? yang:hex-string
+--ro e-inter-area-prefix
| +--ro e-inter-prefix-tlvs* []
| +--ro unknown-tlv
| | +--ro type? uint16
| | +--ro length? uint16
| | +--ro value? yang:hex-string
| +--ro inter-prefix-tlv
| +--ro metric? ospf:ospf-metric
| +--ro prefix? inet:ip-prefix
| +--ro prefix-options
| | +--ro prefix-options* identityref
| +--ro sub-tlvs* []
| +--ro unknown-sub-tlv
| +--ro type? uint16
| +--ro length? uint16
| +--ro value? yang:hex-string
+--ro e-inter-area-router
| +--ro e-inter-router-tlvs* []
| +--ro unknown-tlv
| | +--ro type? uint16
| | +--ro length? uint16
| | +--ro value? yang:hex-string
| +--ro inter-router-tlv
| +--ro lsa-options
| | +--ro lsa-options* identityref
| +--ro metric? ospf:ospf-metric
| +--ro destination-router-id? rt-types:router-id
| +--ro sub-tlvs* []
| +--ro unknown-sub-tlv
| +--ro type? uint16
| +--ro length? uint16
| +--ro value? yang:hex-string
+--ro e-intra-area-prefix
+--ro referenced-ls-type? uint16
+--ro referenced-link-state-id? uint32
+--ro referenced-adv-router? rt-types:router-id
+--ro e-intra-prefix-tlvs* []
+--ro unknown-tlv
| +--ro type? uint16
| +--ro length? uint16
| +--ro value? yang:hex-string
+--ro intra-prefix-tlv
+--ro metric? ospf:ospf-metric
+--ro prefix? inet:ip-prefix
+--ro prefix-options
| +--ro prefix-options* identityref
+--ro sub-tlvs* []
+--ro unknown-sub-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:
+--ro e-as-external
+--ro e-external-tlvs* []
+--ro unknown-tlv
| +--ro type? uint16
| +--ro length? uint16
| +--ro value? yang:hex-string
+--ro external-prefix-tlv
+--ro flags
| +--ro ospfv3-e-external-prefix-bits* identityref
+--ro metric? ospf:ospf-metric
+--ro prefix? inet:ip-prefix
+--ro prefix-options
| +--ro prefix-options* identityref
+--ro sub-tlvs* []
+--ro ipv6-fwd-addr-sub-tlv
| +--ro forwarding-address? inet:ipv6-address
+--ro ipv4-fwd-addr-sub-tlv
| +--ro forwarding-address? inet:ipv4-address
+--ro route-tag-sub-tlv
| +--ro route-tag? uint32
+--ro unknown-sub-tlv
+--ro type? uint16
+--ro length? uint16
+--ro value? yang:hex-string4. OSPFv3 Extended LSA YANG Module 💖
time for the actual YANG module 🎀 quick heads up first: a couple of RFCs aren't mentioned in the text itself but do show up in the "ietf-ospfv3-extended-lsa.yang" module, and those are [RFC6991] and [RFC8294] 🫶
<CODE BEGINS> file "ietf-ospfv3-extended-lsa@2024-06-07.yang"
module ietf-ospfv3-extended-lsa {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-ospfv3-extended-lsa";
prefix ospfv3-e-lsa;
import ietf-routing-types {
prefix rt-types;
reference
"RFC 8294: Common YANG Data Types for the Routing Area";
}
import ietf-inet-types {
prefix inet;
reference
"RFC 6991: Common YANG Data Types";
}
import ietf-routing {
prefix rt;
reference
"RFC 8349: A YANG Data Model for Routing
Management (NMDA Version)";
}
import ietf-ospf {
prefix ospf;
reference
"RFC 9129: YANG Data Model for the OSPF Protocol";
}
organization
"IETF LSR - Link State Routing Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/lsr/>
WG List: <mailto:lsr@ietf.org>
Author: Acee Lindem
<mailto:acee.ietf@gmail.com>
Author: Sharmila Palani
<mailto:sharmila.palani@microsoft.com>
Author: Yingzhen Qu
<mailto:yingzhen.ietf@gmail.com>";
description
"This YANG module defines the configuration and operational
state for OSPFv3 Extended LSAs, which is common across all
vendor implementations. The semantics and encodings for
OSPFv3 Extended LSAs are described in RFC 8362. OSPFv3
Extended LSAs provide extensible TLV-based LSAs for the base
LSA types defined in RFC 5340.
This YANG data model conforms to the Network Management
Datastore Architecture (NMDA) as described in RFC 8342.
Copyright (c) 2024 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject to
the license terms contained in, the Revised BSD License set
forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC 9587; see the
RFC itself for full legal notices.";
reference
"RFC 9587: YANG Data Model for OSPFv3 Extended Link State
Advertisements (LSAs)";okay bestie, the identities are literally the main character of this section 💖 here's the rest of the YANG module 🦋
revision 2024-06-07 {
description
"Initial revision.";
reference
"RFC 9587: YANG Data Model for OSPFv3 Extended Link State
Advertisements (LSAs)";
}
/*
* OSPFv3 Extended LSA Type Identities
*/
identity ospfv3-e-router-lsa {
base ospf:ospfv3-lsa-type;
description
"OSPFv3 E-Router-LSA - Type 0xA021.";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 4.1";
}
identity ospfv3-e-network-lsa {
base ospf:ospfv3-lsa-type;
description
"OSPFv3 E-Network-LSA - Type 0xA022.";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 4.2";
}
identity ospfv3-e-summary-lsa-type {
base ospf:ospfv3-lsa-type;
description
"OSPFv3 Extended Summary LSA types:
E-Inter-Area-Prefix-LSA and E-Inter-Area-Router-LSA.";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Sections 4.3 and 4.4";
}
identity ospfv3-e-inter-area-prefix-lsa {
base ospfv3-e-summary-lsa-type;
description
"OSPFv3 E-Inter-Area-Prefix-LSA - Type 0xA023.";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 4.3";
}
identity ospfv3-e-inter-area-router-lsa {
base ospfv3-e-summary-lsa-type;
description
"OSPFv3 E-Inter-Area-Router-LSA - Type 0xA024.";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 4.4";
}
identity ospfv3-e-external-lsa-type {
base ospf:ospfv3-lsa-type;
description
"OSPFv3 Extended External LSA types:
E-AS-External-LSA and E-NSSA-LSA (where
NSSA expands to Not-So-Stubby-Area).";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Sections 4.5 and 4.6";
}
identity ospfv3-e-as-external-lsa {
base ospfv3-e-external-lsa-type;
description
"OSPFv3 E-AS-External-LSA - Type 0xC025.";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 4.5";
}
identity ospfv3-e-nssa-lsa {
base ospfv3-e-external-lsa-type;
description
"OSPFv3 E-NSSA-LSA - Type 0xA027.";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 4.6";
}
identity ospfv3-e-link-lsa {
base ospf:ospfv3-lsa-type;
description
"OSPFv3 E-Link-LSA - Type 0x8028.";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 4.7";
}
identity ospfv3-e-intra-area-prefix-lsa {
base ospf:ospfv3-lsa-type;
description
"OSPFv3 E-Intra-Area-Prefix-LSA - Type 0xA029.";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 4.8";
}
identity ospfv3-e-prefix-option {
description
"Base identity for OSPFv3 prefix options.";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 3.1";
}
identity nu-bit {
base ospfv3-e-prefix-option;
description
"When set, the prefix should be excluded
from IPv6 unicast calculations.";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 3.1
RFC 5340: OSPF for IPv6, Appendix A.4.1.1";
}
identity la-bit {
base ospfv3-e-prefix-option;
description
"When set, the prefix is actually an IPv6 interface
address of the advertising router.";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 3.1
RFC 5340: OSPF for IPv6, Appendix A.4.1.1";
}
identity p-bit {
base ospfv3-e-prefix-option;
description
"When set, the NSSA prefix should be translated to an
E-AS-External-LSA and advertised by the translating
NSSA Border Router.";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 3.1
RFC 5340: OSPF for IPv6, Appendix A.4.1.1";
}
identity dn-bit {
base ospfv3-e-prefix-option;
description
"When set, the E-Inter-Area-Prefix-LSA or
E-AS-External-LSA prefix has been advertised as an
L3VPN prefix.";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 3.1
RFC 5340: OSPF for IPv6, Appendix A.4.1.1";
}
identity n-bit {
base ospfv3-e-prefix-option;
description
"When set, the prefix is a host address that identifies
the advertising router.";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 3.1
RFC 5340: OSPF for IPv6, Appendix A.4.1.1";
}
identity ospfv3-e-external-prefix-option {
description
"Base identity for OSPFv3 external prefix options.";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 3.6";
}
identity e-bit {
base ospfv3-e-external-prefix-option;
description
"When the E-bit is set, the metric specified is a Type 2
external metric. This means the metric is considered larger
than any intra-AS path. When the E-bit is clear, the
specified metric is a Type 1 external metric. This means
that it is expressed in the same units as other LSAs (i.e.,
the same units as the interface costs in Router-LSAs).";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 3.6";
}
grouping unknown-sub-tlv {
description
"Unknown TLV grouping.";
container unknown-sub-tlv {
uses ospf:tlv;
description
"Unknown External TLV sub-TLV.";
}
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 6.3";
}
grouping ospfv3-lsa-prefix {
description
"OSPFv3 LSA prefix.";
leaf prefix {
type inet:ip-prefix;
description
"LSA prefix.";
}
container prefix-options {
leaf-list prefix-options {
type identityref {
base ospfv3-e-prefix-option;
}
description
"OSPFv3 prefix options flag list. This list will
contain the identities for the OSPFv3 options
that are set for the OSPFv3 prefix.";
}
description
"Prefix options.";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 3.1";
}
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 3";
}
grouping external-prefix-tlv {
container external-prefix-tlv {
description
"External-Prefix TLV.";
container flags {
leaf-list ospfv3-e-external-prefix-bits {
type identityref {
base ospfv3-e-external-prefix-option;
}
description
"OSPFv3 External-Prefix TLV bits list.";
}
description
"External prefix flags.";
}
leaf metric {
type ospf:ospf-metric;
description
"External prefix metric.";
}
uses ospfv3-lsa-prefix;
list sub-tlvs {
description
"External-Prefix TLV sub-TLVs.";
container ipv6-fwd-addr-sub-tlv {
description
"IPv6-Forwarding-Address sub-TLV for
E-AS-External-LSAs and E-NSSA-LSAs for the IPv6
address family.";
leaf forwarding-address {
type inet:ipv6-address;
description
"IPv6 forwarding address.";
}
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 3.10";
}
container ipv4-fwd-addr-sub-tlv {
description
"IPv4-Forwarding-Address sub-TLV for
E-AS-External-LSAs and E-NSSA-LSAs for the IPv4
address family.";
leaf forwarding-address {
type inet:ipv4-address;
description
"IPv4 forwarding address.";
}
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 3.11";
}
container route-tag-sub-tlv {
description
"Route-Tag sub-TLV.";
leaf route-tag {
type uint32;
description
"Route tag.";
}
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 3.12";
}
uses unknown-sub-tlv;
}
}
description
"External-Prefix TLV grouping.";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 3.6";
}
grouping intra-area-prefix-tlv {
container intra-prefix-tlv {
description
"Intra-Area-Prefix-LSA TLV.";
leaf metric {
type ospf:ospf-metric;
description
"Intra-Area Prefix metric.";
}
uses ospfv3-lsa-prefix;
list sub-tlvs {
description
"Intra-Area-Prefix TLV sub-TLVs.";
uses unknown-sub-tlv;
}
}
description
"Intra-Area-Prefix TLV grouping.";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 3.7";
}
grouping ipv6-link-local-addr-tlv {
container ipv6-link-local-addr-tlv {
description
"IPv6 Link-Local Address TLV.";
leaf link-local-address {
type inet:ipv6-address;
description
"IPv6 Link-Local address.";
}
list sub-tlvs {
description
"IPv6 Link-Local Address TLV sub-TLVs.";
uses unknown-sub-tlv;
}
}
description
"IPv6 Link-Local Address TLV grouping.";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 3.8";
}
grouping ipv4-link-local-addr-tlv {
container ipv4-link-local-addr-tlv {
description
"IPv4 Link-Local Address TLV.";
leaf link-local-address {
type inet:ipv4-address;
description
"IPv4 Link-Local address.";
}
list sub-tlvs {
description
"IPv4 Link-Local Address TLV sub-TLVs.";
uses unknown-sub-tlv;
}
}
description
"IPv4 Link-Local Address TLV grouping.";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 3.9";
}
/* Configuration */Okay bestie, this part is all YANG code, so every single character stays exactly as written 💅 The prose inside the descriptions is code too, so I'm keeping it verbatim. Let's go 🦋
augment "/rt:routing/rt:control-plane-protocols"
+ "/rt:control-plane-protocol/ospf:ospf" {
when "../rt:type = 'ospf:ospfv3'" {
description
"This augments the OSPFv3 routing protocol when used.";
}
description
"This augments the OSPFv3 protocol instance-level
configuration with Extended LSA support. When enabled,
OSPFv3 Extended LSAs will be advertised and OSPFv3 Legacy
LSAs will not be advertised. When disabled, OSPFv3 Legacy
LSAs will be advertised. However, OSPFv3 Extended LSAs
could still be advertised in Extended LSA Sparse Mode to
support incrementally deployed features as described in
Section 6.2 of RFC 8362.";
leaf extended-lsa-support {
type boolean;
default "false";
description
"Enable OSPFv3 Extended LSA support for the OSPFv3
domain.";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Appendix A - Global Configuration Support";
}
}
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ospf:ospf/ospf:"
+ "areas/ospf:area" {
when "../../../rt:type = 'ospf:ospfv3'" {
description
"This augments the OSPFv3 protocol area-level
configuration when used.";
}
description
"This augments the OSPFv3 protocol area-level
configuration with Extended LSA support.";
leaf extended-lsa-support {
type boolean;
must "derived-from(../ospf:area-type,'stub-nssa-area') or "
+ "(current() = 'true') or "
+ "(../../../extended-lsa-support = 'false')" {
description
"For regular areas, i.e., areas where AS-scoped LSAs
are flooded, disabling AreaExtendedLSASupport at the
area level is prohibited when ExtendedLSASupport is
enabled at the instance level. E-AS-External-LSAs
are flooded into all OSPFv3 regular areas (i.e., not
a stub or an NSSA), and disabling support at the
area level is not possible.";
}
description
"This augments the OSPFv3 protocol area-level
configuration with Extended LSA support. When enabled,
OSPFv3 Extended LSAs will be advertised and OSPFv3 Legacy
LSAs will not be advertised. When disabled, OSPFv3
Legacy LSAs will be advertised. However, OSPFv3 Extended
LSAs could still be advertised in Extended LSA Sparse
Mode to support incrementally deployed features as
described in Section 6.2 of RFC 8362. If not specified,
Extended LSA support status is inherited from the
instance-level configuration.";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Appendix B - Area Configuration Support";
}
}
/*
* Link State Database (LSDB) Augmentations
*/
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" {
when "../../../../../../../../../../../"
+ "rt:type = 'ospf:ospfv3'" {
description
"This augmentation is only valid for OSPFv3.";
}
description
"This augmentation adds OSPFv3 Link-scoped Extended LSAs
to the operational state for an interface Link State
Database (LSDB).";
container e-link {
when "../../ospf:header/ospf:type = "
+ "'ospfv3-e-lsa:ospfv3-e-link-lsa'" {
description
"Only applies to E-Link-LSAs.";
}
description
"E-Link-LSA contents.";
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 4.7";
leaf rtr-priority {
type uint8;
description
"Router priority for the interface.";
}
uses ospf:ospfv3-lsa-options;
list e-link-tlvs {
description
"E-Link-LSA TLVs.";
container unknown-tlv {
uses ospf:tlv;
description
"Unknown E-Link TLV.";
}
uses intra-area-prefix-tlv;
uses ipv6-link-local-addr-tlv;
uses ipv4-link-local-addr-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" {
when "../../../../../../../"
+ "rt:type = 'ospf:ospfv3'" {
description
"This augmentation is only valid for OSPFv3.";
}
description
"This augmentation adds OSPFv3 AS-scoped Extended LSAs to
the operational state for an AS instance-level LSDB.";
container e-as-external {
when "../../ospf:header/ospf:type = "
+ "'ospfv3-e-lsa:ospfv3-e-as-external-lsa'" {
description
"Only applies to E-AS-External-LSAs.";
}
description
"E-AS-External-LSA contents.";
list e-external-tlvs {
description
"E-AS-External-LSA TLVs.";
container unknown-tlv {
uses ospf:tlv;
description
"Unknown E-External TLV.";
}
uses external-prefix-tlv;
}
reference
"RFC 8362: OSPFv3 Link State Advertisement (LSA)
Extensibility, Section 4.5";
}
}
}
<CODE ENDS>5. Security Considerations 🔐
okay bestie, let's talk security 🫶 this YANG module is designed to be accessed through network management protocols like NETCONF [RFC6241] or RESTCONF [RFC8040]. For NETCONF, the lowest layer is the secure transport layer, and the mandatory-to-implement secure transport is Secure Shell (SSH) [RFC6242]. For RESTCONF, the lowest layer is HTTPS, and the mandatory-to-implement secure transport is TLS [RFC8446]. ✨
The Network Configuration Access Control Model (NACM) [RFC8341] is what lets you restrict access for particular NETCONF or RESTCONF users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content. it's giving access control realness 💅
⚠️ Heads up: a bunch of the data nodes inietf-ospfv3-extended-lsa.yangare writable, creatable, and deletable (that'sconfig true, which is the default 🙈). These nodes may be sensitive or vulnerable in some network environments. Write operations (likeedit-config) to them without proper protection can have a negative effect on network operations. 💀
The sensitive subtrees and data nodes are:
/ospf:ospf/extended-lsa-support
/ospf:ospf/ospf:areas/ospf:area/extended-lsa-supportOkay, the scary part 😭 being able to disable or enable OSPFv3 Extended LSA support can result in a Denial-of-Service (DoS) attack. The reason is that OSPFv3 routers will use solely OSPFv3 Extended LSAs or OSPFv3 Legacy LSAs for the OSPFv3 SPF computation. If routers are using different types of LSAs, you get incomplete reachability and possible partitioning of the OSPFv3 routing domain. Literally a routing mess 🌪️. For more on OSPFv3 Extended LSA compatibility, check Section 6 of [RFC8362] 📖.
Some of the readable data nodes in the ietf-ospfv3-extended-lsa.yang module may also be considered sensitive or vulnerable in some network environments. So it's important to control read access (for example via get, get-config, or notification) to these data nodes. 👀
Last but not least, exposing the Link State Database (LSDB) exposes the detailed topology of the network 🗺️. That includes topological information from other routers too. This may be undesirable because exposure may facilitate other attacks. Network operators may also consider their topologies to be sensitive confidential data, and honestly, same 🙈🔒
6. IANA Considerations 🎀
okay so IANA did some paperwork for us 📋💅 Per this document, they registered a URI in the "IETF XML Registry" [RFC3688]. The URI is an XML namespace, so there's no XML to attach to it. 🌸
URI: urn:ietf:params:xml:ns:yang:ietf-ospfv3-extended-lsa
Registrant Contact: The IESG.
XML: N/A; the requested URI is an XML namespace.They also registered a YANG module in the "YANG Module Names" registry [RFC6020], and this is giving very organized energy ✨
Name: ietf-ospfv3-extended-lsa
Maintained by IANA: N
Namespace: urn:ietf:params:xml:ns:yang:ietf-ospfv3-extended-lsa
Prefix: ospfv3-e-lsa
Reference: RFC 95877. References 📚
7.1. Normative References
bestie, these are the sources the spec totally depends on, so they're the must-reads 🫶 Here they are, exactly as written:
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
[RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF
for IPv6", RFC 5340, DOI 10.17487/RFC5340, July 2008,
<https://www.rfc-editor.org/info/rfc5340>.
[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
the Network Configuration Protocol (NETCONF)", RFC 6020,
DOI 10.17487/RFC6020, October 2010,
<https://www.rfc-editor.org/info/rfc6020>.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<https://www.rfc-editor.org/info/rfc6241>.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure
Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
<https://www.rfc-editor.org/info/rfc6242>.
[RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types",
RFC 6991, DOI 10.17487/RFC6991, July 2013,
<https://www.rfc-editor.org/info/rfc6991>.
[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>.
[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>.
[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>.
[RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
and R. Wilton, "Network Management Datastore Architecture
(NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
<https://www.rfc-editor.org/info/rfc8342>.
[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>.
[RFC8362] Lindem, A., Roy, A., Goethals, D., Reddy Vallem, V., and
F. Baker, "OSPFv3 Link State Advertisement (LSA)
Extensibility", RFC 8362, DOI 10.17487/RFC8362, April
2018, <https://www.rfc-editor.org/info/rfc8362>.
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>.
[RFC9129] Yeung, D., Qu, Y., Zhang, Z., Chen, I., and A. Lindem,
"YANG Data Model for the OSPF Protocol", RFC 9129,
DOI 10.17487/RFC9129, October 2022,
<https://www.rfc-editor.org/info/rfc9129>.
[W3C.REC-xml-20081126]
Bray, T., Paoli, J., Sperberg-McQueen, C. M., Maler, E.,
and F. Yergeau, "Extensible Markup Language (XML) 1.0
(Fifth Edition)", W3C Recommendation REC-xml-20081126,
November 2008, <https://www.w3.org/TR/xml/>.7.2. Informative References
these ones are extra reading, good for context but not required 🌈
[RFC7951] Lhotka, L., "JSON Encoding of Data Modeled with YANG",
RFC 7951, DOI 10.17487/RFC7951, August 2016,
<https://www.rfc-editor.org/info/rfc7951>.
[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>.Appendix A. Configuration Example 🧚
okay the grand finale!! 🎉 This is an XML example, following [W3C.REC-xml-20081126], that uses the YANG data model for OSPFv3 Extended LSAs. The line breaks are there per [RFC8792] and are just for display, so don't stress about them 💖
Note: '' line wrapping per RFC 8792.
<?xml version='1.0' encoding='UTF-8'?>
<routing xmlns="urn:ietf:params:xml:ns:yang:ietf-routing">
<router-id>192.0.2.1</router-id>
<control-plane-protocols>
<control-plane-protocol>
<type xmlns:ospf="urn:ietf:params:xml:ns:yang:ietf-ospf">\
ospf:ospfv3</type>
<name>"OSPFv3"</name>
<ospf xmlns="urn:ietf:params:xml:ns:yang:ietf-ospf">
<extended-lsa-support xmlns="urn:ietf:params:xml:ns:yang:\
ietf-ospfv3-extended-lsa">true</extended-lsa-support>
</ospf>
</control-plane-protocol>
</control-plane-protocols>
</routing>And here's the exact same config in JSON format [RFC7951], because we love a choice 🍓
{
"routing": {
"router-id": "192.0.2.1",
"control-plane-protocols": {
"control-plane-protocol": {
"type": "ospf:ospfv3",
"name": "\"OSPFv3\"",
"ospf": {
"extended-lsa-support": true
}
}
}
}
}Acknowledgements 🫶
the YANG data model in this document was built with a whole suite of YANG tools that tons of authors wrote and maintain, so shoutout to all of them 🔥
Huge thanks to Tom Petch, Mahesh Jethanandani, Renato Westphal, Victoria Pritchard, Reshad Rahman, and Chris Hopps for reviewing and commenting. You're all iconic 👑
Authors' Addresses 💜
here's where you can find the authors, who literally did all of this ✨
Acee Lindem
LabN Consulting, L.L.C.
301 Midenhall Way
Cary, NC 27513
United States of America
Email: acee.ietf@gmail.com
Sharmila Palani
Microsoft
1 Microsoft Way
Redmond, WA 98052
United States of America
Email: sharmila.palani@microsoft.com
Yingzhen Qu
Futurewei Technologies
2330 Central Expressway
Santa Clara, CA 95050
United States of America
Email: yingzhen.ietf@gmail.com📦 where this page comes from
- ietf: rfc9587 2024-06
- 💖 girlified by claude-haiku-5-5 on : a language model's rewrite of the original, under its terms