RFC 9070
YANG Data Model for MPLS LDP
RFC 9070: YANG Data Model for MPLS LDP 💖
- Who wrote it: K. Raza (Ed.) from Cisco Systems, R. Asati from Cisco Systems, X. Liu from IBM Corporation, S. Easale from Juniper Networks, X. Chen from Huawei Technologies, and H. Shah from Ciena Corporation. 👑
- Category: Standards Track, ISSN 2070-1721 🎀
- Date: March 2022 🦋
- Obsoletes/Updates: the header doesn't list any 🌸
- Stream: IETF, the Internet Engineering Task Force 🌈
Abstract ✨
This document describes a YANG data model for the Multiprotocol Label Switching (MPLS) Label Distribution Protocol (LDP). The model also serves as the base model to define the Multipoint LDP (mLDP) model. 💅
The YANG modules in this document conform to the Network Management Datastore Architecture (NMDA). 🔥
Status of This Memo 🧚
This is an Internet Standards Track document. 💜
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 7841. 🫶
Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at https://www.rfc-editor.org/info/rfc9070. 🍓
Copyright Notice 🌸
Copyright (c) 2022 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. 🙈
Table of Contents 🦋
1. Introduction
1.1. Base and Extended
2. Specification of Requirements
3. Overview
4. The Complete Tree
5. Configuration
5.1. Configuration Hierarchy
5.1.1. Global Parameters
5.1.2. Capabilities Parameters
5.1.3. Per-Address-Family Parameters
5.1.4. Hello Discovery Parameters
5.1.5. Peer Parameters
5.1.6. Forwarding Parameters
6. Operational State
6.1. Adjacency State
6.2. Peer State
6.3. Bindings State
6.4. Capabilities State
7. Notifications
8. Action
9. YANG Specification
9.1. Base
9.2. Extended
10. Security Considerations
10.1. YANG Data Model
10.1.1. Writable Nodes
10.1.2. Readable Nodes
10.1.3. RPC Operations
10.1.4. Notifications
11. IANA Considerations
12. Normative References
13. Informative References
Appendix A. Data Tree Example
Acknowledgments
Contributors
Authors' Addresses1. Introduction 🌷
The Network Configuration Protocol (NETCONF) [RFC6241] is one of the network management protocols that defines mechanisms to manage network devices. YANG [RFC6020] [RFC7950] is a modular language that represents data structures in an XML tree format and is used as a data modeling language for NETCONF. 🧠
This document introduces a YANG data model for the MPLS Label Distribution Protocol (LDP) [RFC5036]. This model also covers LDP IPv6 [RFC7552] and LDP capability [RFC5561] specifications. 💅
The data model is defined for the following constructs that are used for managing the protocol:
- Configuration ⚙️
- Operational State 👀
- Executables (Actions) 🎬
- Notifications 🔔
This document is organized to define the data model for each of the above constructs in the sequence as listed above. 📋
1.1. Base and Extended 🍰
The configuration and state items are divided into the following two broad categories:
- Base
- Extended
The "base" category contains the basic and fundamental features that are covered in LDP base specification [RFC5036] and constitute the minimum requirements for a typical base LDP deployment, whereas the "extended" category contains other non-base features. All the items in a base category are mandatory and, hence, no "if-feature" is allowed under the "base" category. The base and extended categories are defined in their own modules as described later. 🌈
The examples of a base feature include the configuration of LDP lsr-id, enabling LDP interfaces, setting passwords for LDP sessions, etc., whereas the examples of an extended feature include inbound/outbound label policies, IGP Sync [RFC5443], downstream on demand, etc. It is worth highlighting that LDP IPv6 [RFC7552] is also categorized as an extended feature. ✨
While "base" model support will suffice for small deployments, it is expected that large deployments will require both "base" and "extended" model support from the vendors. 🫶
2. Specification of Requirements 📜
In this document, the word "IP" is used to refer to both IPv4 and IPv6 unless otherwise explicitly stated. For example, "IP address family" should be read as "IPv4 and/or IPv6 address family". 🦋
3. Overview 🔭
This document defines two new modules for LDP YANG support:
- "ietf-mpls-ldp": A module that specifies the base LDP features and augments
/rt:routing/rt:control-plane-protocols/rt:control-plane-protocoldefined in [RFC8349]. We define the new identity'mpls-ldp'for LDP; the model allows only a single instance of'mpls-ldp'. 💜 - "ietf-mpls-ldp-extended": A module that specifies the extended LDP features and augments the base LDP module. 🍓
It is to be noted that the mLDP YANG data model [MPLS-MLDP-YANG] augments LDP base and extended modules to specify the mLDP-specific base and extended features. 🌸
There are four types of containers in our module(s):
- Read-write parameters for configuration (Section 5) 🛠️
- Read-only parameters for operational state (Section 6) 👁️
- Notifications for events (Section 7) 📣
- RPCs for executing commands to perform some action (Section 8) 🎯
The modules in this document conform to the Network Management Datastore Architecture (NMDA) defined in [RFC8342]. The operational state data is combined with the associated configuration data in the same hierarchy [RFC8407]. When protocol states are retrieved from the NMDA operational state datastore, the returned states cover all "config true" (rw) and "config false" (ro) nodes defined in the schema. 💖
The following diagram depicts high-level LDP YANG tree organization and hierarchy: 🗺️
+-- rw routing
+-- rw control-plane-protocols
+-- rw control-plane-protocol
+-- rw mpls-ldp
+-- rw ...
+-- rw ... // base
| +-- rw ...
| +-- ro ...
| +--
+-- ro ...
| +-- ro ...
| +-- ro ...
| +--
+-- rw ldp-ext: .... // extended
| +-- rw ...
| +-- ro ...
| +--
+-- ro ...
+-- ro ...
+-- ro ...
rpcs:
+-- x mpls-ldp-some_action
+-- x . . . . .
notifications:
+--- n mpls-ldp-some_event
+--- n ...
Figure 1: LDP YANG Tree OrganizationBefore going into data model details, it is important to take note of the following points: 👀
- This model aims to address only the core LDP parameters as per RFC specification, as well as well-known and widely deployed manageability controls (such as label filtering policies to apply filtering rules on the assignment, advertisement, and acceptance for label bindings). Any vendor-specific feature should be defined in a vendor-specific augmentation of this model. 🎀
- Multi-topology LDP [RFC7307] is beyond the scope of this document. 🙅
- This model does not cover any applications running on top of LDP, nor does it cover any Operations, Administration, and Maintenance (OAM) procedures for LDP. 🚫
- This model is a VRF-centric model. It is important to note that [RFC4364] defines VPN Routing and Forwarding (VRF) tables and default forwarding tables as different; however, from a YANG modeling perspective, this introduces unnecessary complications; hence, we are treating the default forwarding table as just another VRF. 🌐
- A "network-instance", as defined in [RFC8529], refers to a VRF instance (both default and non-default) within the scope of this model. 🏠
- This model supports two address families, namely, "ipv4" and "ipv6". 🌍
- This model assumes platform-wide label space (i.e., label space Id of zero). However, when upstream label assignment [RFC6389] is in use, an upstream assigned label is looked up in a Context-Specific Label Space as defined in [RFC5331]. 🏷️
- The label and peer policies (including filters) are defined using prefix-set and neighbor-set, respectively, as defined in the routing-policy model [RFC9067]. 📍
- This model uses the terms LDP "neighbor/adjacency", "session", and "peer" with the following semantics:
- Neighbor/Adjacency: An LDP-enabled Label Switching Router (LSR) that is discovered through LDP discovery mechanisms. 🔍
- Session: An LDP neighbor with whom a TCP connection has been established. 🤝
- Peer: An LDP session that has successfully progressed beyond its initialization phase and is either already exchanging the bindings or is ready to do so. 💫
- It is to be noted that LDP Graceful Restart (GR) mechanisms defined in [RFC3478] allow keeping the exchanged bindings for some time after a session goes down with a peer. We refer to such a state as belonging to a "stale" peer, i.e., keeping peer bindings from a peer with whom currently there is either no connection established or connection is established but the GR session is in recovery state. When used in this document, the above terms will refer strictly to the semantics and definitions defined for them. 🔁
A simplified graphical tree representation of base and extended LDP YANG data models is presented in Figure 2. The meaning of the symbols in these tree diagrams is defined in [RFC8340]. 🌳
The actual YANG specification for base and extended modules is captured in Section 9. 📚
While presenting the YANG tree view and actual specification, this document assumes readers are familiar with the concepts of YANG modeling, its presentation, and its compilation. 🤓
4. The Complete Tree 🌳
The following is a complete tree representation of configuration, state, notification, and RPC items under LDP base and extended modules. 🍒
okay so the tree keeps going, and it is WILD 🌸 the ldp-ext: prefix is just the LDP extensions module hanging out next to the base stuff 💅
module: ietf-mpls-ldp
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol:
+--rw mpls-ldp
+--rw global
| +--rw capability
| | +--rw ldp-ext:end-of-lib {capability-end-of-lib}?
| | | +--rw ldp-ext:enabled? boolean
| | +--rw ldp-ext:typed-wildcard-fec
| | | {capability-typed-wildcard-fec}?
| | | +--rw ldp-ext:enabled? boolean
| | +--rw ldp-ext:upstream-label-assignment
| | {capability-upstream-label-assignment}?
| | +--rw ldp-ext:enabled? boolean
| +--rw graceful-restart
| | +--rw enabled? boolean
| | +--rw reconnect-time? uint16
| | +--rw recovery-time? uint16
| | +--rw forwarding-holdtime? uint16
| | +--rw ldp-ext:helper-enabled? boolean
| | {graceful-restart-helper-mode}?
| +--rw lsr-id?
| | rt-types:router-id
| +--rw address-families
| | +--rw ipv4!
| | | +--rw enabled? boolean
| | | +--ro label-distribution-control-mode? enumeration
| | | +--ro bindings
| | | | +--ro address* [address]
| | | | | +--ro address inet:ipv4-address
| | | | | +--ro advertisement-type? advertised-received
| | | | | +--ro peer
| | | | | +--ro lsr-id? leafref
| | | | | +--ro label-space-id? leafref
| | | | +--ro fec-label* [fec]
| | | | +--ro fec inet:ipv4-prefix
| | | | +--ro peer*
| | | | [lsr-id label-space-id advertisement-type]
| | | | +--ro lsr-id leafref
| | | | +--ro label-space-id leafref
| | | | +--ro advertisement-type
| | | | | advertised-received
| | | | +--ro label?
| | | | | rt-types:mpls-label
| | | | +--ro used-in-forwarding? boolean
| | | +--rw ldp-ext:label-policy
| | | | +--rw ldp-ext:advertise
| | | | | +--rw ldp-ext:egress-explicit-null
| | | | | | +--rw ldp-ext:enabled? boolean
| | | | | +--rw ldp-ext:prefix-list?
| | | | | prefix-list-ref
| | | | +--rw ldp-ext:accept
| | | | | +--rw ldp-ext:prefix-list? prefix-list-ref
| | | | +--rw ldp-ext:assign
| | | | {policy-label-assignment-config}?
| | | | +--rw ldp-ext:independent-mode
| | | | | +--rw ldp-ext:prefix-list? prefix-list-ref
| | | | +--rw ldp-ext:ordered-mode
| | | | {policy-ordered-label-config}?
| | | | +--rw ldp-ext:egress-prefix-list?
| | | | prefix-list-ref
| | | +--rw ldp-ext:transport-address?
| | | inet:ipv4-address
| | +--rw ldp-ext:ipv6!
| | +--rw ldp-ext:enabled?
| | | boolean
| | +--rw ldp-ext:label-policy
| | | +--rw ldp-ext:advertise
| | | | +--rw ldp-ext:egress-explicit-null
| | | | | +--rw ldp-ext:enabled? boolean
| | | | +--rw ldp-ext:prefix-list?
| | | | prefix-list-ref
| | | +--rw ldp-ext:accept
| | | | +--rw ldp-ext:prefix-list? prefix-list-ref
| | | +--rw ldp-ext:assign
| | | {policy-label-assignment-config}?
| | | +--rw ldp-ext:independent-mode
| | | | +--rw ldp-ext:prefix-list? prefix-list-ref
| | | +--rw ldp-ext:ordered-mode
| | | {policy-ordered-label-config}?
| | | +--rw ldp-ext:egress-prefix-list?
| | | prefix-list-ref
| | +--rw ldp-ext:transport-address
| | | inet:ipv6-address
| | +--ro ldp-ext:label-distribution-control-mode?
| | | enumeration
| | +--ro ldp-ext:bindings
| | +--ro ldp-ext:address* [address]
| | | +--ro ldp-ext:address
| | | | inet:ipv6-address
| | | +--ro ldp-ext:advertisement-type?
| | | | advertised-received
| | | +--ro ldp-ext:peer
| | | +--ro ldp-ext:lsr-id? leafref
| | | +--ro ldp-ext:label-space-id? leafref
| | +--ro ldp-ext:fec-label* [fec]
| | +--ro ldp-ext:fec inet:ipv6-prefix
| | +--ro ldp-ext:peer*
| | [lsr-id label-space-id advertisement-type]
| | +--ro ldp-ext:lsr-id leafref
| | +--ro ldp-ext:label-space-id leafref
| | +--ro ldp-ext:advertisement-type
| | | advertised-received
| | +--ro ldp-ext:label?
| | | rt-types:mpls-label
| | +--ro ldp-ext:used-in-forwarding? boolean
| +--rw ldp-ext:forwarding-nexthop
| | {forwarding-nexthop-config}?
| | +--rw ldp-ext:interfaces
| | +--rw ldp-ext:interface* [name]
| | +--rw ldp-ext:name if:interface-ref
| | +--rw ldp-ext:address-family* [afi]
| | +--rw ldp-ext:afi identityref
| | +--rw ldp-ext:ldp-disable? boolean
| +--rw ldp-ext:igp-synchronization-delay? uint16
+--rw discovery
| +--rw interfaces
| | +--rw hello-holdtime? uint16
| | +--rw hello-interval? uint16
| | +--rw interface* [name]
| | +--rw name
| | | if:interface-ref
| | +--ro next-hello? uint16
| | +--rw address-families
| | | +--rw ipv4!
| | | | +--rw enabled? boolean
| | | | +--ro hello-adjacencies
| | | | | +--ro hello-adjacency* [adjacent-address]
| | | | | +--ro adjacent-address
| | | | | | inet:ipv4-address
| | | | | +--ro flag* identityref
| | | | | +--ro hello-holdtime
| | | | | | +--ro adjacent? uint16
| | | | | | +--ro negotiated? uint16
| | | | | | +--ro remaining? uint16
| | | | | +--ro next-hello? uint16
| | | | | +--ro statistics
| | | | | | +--ro discontinuity-time
| | | | | | | yang:date-and-time
| | | | | | +--ro hello-received?
| | | | | | | yang:counter64
| | | | | | +--ro hello-dropped?
| | | | | | yang:counter64
| | | | | +--ro peer
| | | | | +--ro lsr-id? leafref
| | | | | +--ro label-space-id? leafref
| | | | +--rw ldp-ext:transport-address? union
| | | +--rw ldp-ext:ipv6!
| | | +--rw ldp-ext:enabled? boolean
| | | +--ro ldp-ext:hello-adjacencies
| | | | +--ro ldp-ext:hello-adjacency*
| | | | [adjacent-address]
| | | | +--ro ldp-ext:adjacent-address
| | | | | inet:ipv6-address
| | | | +--ro ldp-ext:flag*
| | | | | identityref
| | | | +--ro ldp-ext:hello-holdtime
| | | | | +--ro ldp-ext:adjacent? uint16
| | | | | +--ro ldp-ext:negotiated? uint16
| | | | | +--ro ldp-ext:remaining? uint16
| | | | +--ro ldp-ext:next-hello? uint16
| | | | +--ro ldp-ext:statistics
| | | | | +--ro ldp-ext:discontinuity-time
| | | | | | yang:date-and-time
| | | | | +--ro ldp-ext:hello-received?
| | | | | | yang:counter64
| | | | | +--ro ldp-ext:hello-dropped?
| | | | | yang:counter64
| | | | +--ro ldp-ext:peer
| | | | +--ro ldp-ext:lsr-id? leafref
| | | | +--ro ldp-ext:label-space-id? leafref
| | | +--rw ldp-ext:transport-address? union
| | +--rw ldp-ext:hello-holdtime? uint16
| | | {per-interface-timer-config}?
| | +--rw ldp-ext:hello-interval? uint16
| | | {per-interface-timer-config}?
| | +--rw ldp-ext:igp-synchronization-delay? uint16
| | {per-interface-timer-config}?
| +--rw targeted
| +--rw hello-holdtime? uint16
| +--rw hello-interval? uint16
| +--rw hello-accept
| | +--rw enabled? boolean
| | +--rw ldp-ext:neighbor-list? neighbor-list-ref
| | {policy-targeted-discovery-config}?
| +--rw address-families
| +--rw ipv4!
| | +--ro hello-adjacencies
| | | +--ro hello-adjacency*
| | | [local-address adjacent-address]
| | | +--ro local-address inet:ipv4-address
| | | +--ro adjacent-address inet:ipv4-address
| | | +--ro flag* identityref
| | | +--ro hello-holdtime
| | | | +--ro adjacent? uint16
| | | | +--ro negotiated? uint16
| | | | +--ro remaining? uint16
| | | +--ro next-hello? uint16
| | | +--ro statistics
| | | | +--ro discontinuity-time
| | | | | yang:date-and-time
| | | | +--ro hello-received?
| | | | | yang:counter64
| | | | +--ro hello-dropped?
| | | | yang:counter64
| | | +--ro peer
| | | +--ro lsr-id? leafref
| | | +--ro label-space-id? leafref
| | +--rw target* [adjacent-address]
| | +--rw adjacent-address inet:ipv4-address
| | +--rw enabled? boolean
| | +--rw local-address? inet:ipv4-address
| +--rw ldp-ext:ipv6!
| +--ro ldp-ext:hello-adjacencies
| | +--ro ldp-ext:hello-adjacency*
| | [local-address adjacent-address]
| | +--ro ldp-ext:local-address
| | | inet:ipv6-address
| | +--ro ldp-ext:adjacent-addressthe ipv6 targeted section is still coming in the next part, bestie, so stay tuned 🦋✨
| inet:ipv6-address | |||
|---|---|---|---|
| +--ro ldp-ext:flag* | |||
| identityref | |||
| +--ro ldp-ext:hello-holdtime | |||
| +--ro ldp-ext:adjacent? uint16 | |||
| +--ro ldp-ext:negotiated? uint16 | |||
| +--ro ldp-ext:remaining? uint16 | |||
| +--ro ldp-ext:next-hello? uint16 | |||
| +--ro ldp-ext:statistics | |||
| +--ro ldp-ext:discontinuity-time | |||
| yang:date-and-time | |||
| +--ro ldp-ext:hello-received? | |||
| yang:counter64 | |||
| +--ro ldp-ext:hello-dropped? | |||
| yang:counter64 | |||
| +--ro ldp-ext:peer | |||
| +--ro ldp-ext:lsr-id? leafref | |||
| +--ro ldp-ext:label-space-id? leafref | |||
| +--rw ldp-ext:target* [adjacent-address] | |||
| +--rw ldp-ext:adjacent-address | |||
| inet:ipv6-address | |||
| +--rw ldp-ext:enabled? boolean | |||
| +--rw ldp-ext:local-address? | |||
| inet:ipv6-address |
+--rw peers +--rw authentication
| +--rw (authentication-type)? | |
|---|---|
| +--:(password) | |
| +--rw key? string | |
| +--rw crypto-algorithm? identityref | |
| +--:(ldp-ext:key-chain) {key-chain}? | |
| +--rw ldp-ext:key-chain? key-chain:key-chain-ref |
+--rw session-ka-holdtime? uint16 +--rw session-ka-interval? uint16 +--rw peer* [lsr-id label-space-id]
| +--rw lsr-id rt-types:router-id | |||||
|---|---|---|---|---|---|
| +--rw label-space-id uint16 | |||||
| +--rw authentication | |||||
| +--rw (authentication-type)? | |||||
| +--:(password) | |||||
| +--rw key? string | |||||
| +--rw crypto-algorithm? identityref | |||||
| +--:(ldp-ext:key-chain) {key-chain}? | |||||
| +--rw ldp-ext:key-chain? | |||||
| key-chain:key-chain-ref | |||||
| +--rw address-families | |||||
| +--rw ipv4! | |||||
| +--ro hello-adjacencies | |||||
| +--ro hello-adjacency* | |||||
| [local-address adjacent-address] | |||||
| +--ro local-address inet:ipv4-address | |||||
| +--ro adjacent-address inet:ipv4-address | |||||
| +--ro flag* identityref | |||||
| +--ro hello-holdtime | |||||
| +--ro adjacent? uint16 | |||||
| +--ro negotiated? uint16 | |||||
| +--ro remaining? uint16 | |||||
| +--ro next-hello? uint16 | |||||
| +--ro statistics | |||||
| +--ro discontinuity-time | |||||
| yang:date-and-time | |||||
| +--ro hello-received? | |||||
| yang:counter64 | |||||
| +--ro hello-dropped? | |||||
| yang:counter64 | |||||
| +--ro interface? if:interface-ref | |||||
| +--rw ldp-ext:label-policy | |||||
| +--rw ldp-ext:advertise | |||||
| +--rw ldp-ext:prefix-list? prefix-list-ref | |||||
| +--rw ldp-ext:accept | |||||
| +--rw ldp-ext:prefix-list? prefix-list-ref | |||||
| +--rw ldp-ext:ipv6! | |||||
| +--ro ldp-ext:hello-adjacencies | |||||
| +--ro ldp-ext:hello-adjacency* | |||||
| [local-address adjacent-address] | |||||
| +--ro ldp-ext:local-address | |||||
| inet:ipv6-address | |||||
| +--ro ldp-ext:adjacent-address | |||||
| inet:ipv6-address | |||||
| +--ro ldp-ext:flag* | |||||
| identityref | |||||
| +--ro ldp-ext:hello-holdtime | |||||
| +--ro ldp-ext:adjacent? uint16 | |||||
| +--ro ldp-ext:negotiated? uint16 | |||||
| +--ro ldp-ext:remaining? uint16 | |||||
| +--ro ldp-ext:next-hello? uint16 | |||||
| +--ro ldp-ext:statistics | |||||
| +--ro ldp-ext:discontinuity-time | |||||
| yang:date-and-time | |||||
| +--ro ldp-ext:hello-received? | |||||
| yang:counter64 | |||||
| +--ro ldp-ext:hello-dropped? | |||||
| yang:counter64 | |||||
| +--ro ldp-ext:interface? | |||||
| if:interface-ref | |||||
| +--rw ldp-ext:label-policy | |||||
| +--rw ldp-ext:advertise | |||||
| +--rw ldp-ext:prefix-list? prefix-list-ref | |||||
| +--rw ldp-ext:accept | |||||
| +--rw ldp-ext:prefix-list? prefix-list-ref | |||||
| +--ro label-advertisement-mode | |||||
| +--ro local? label-adv-mode | |||||
| +--ro peer? label-adv-mode | |||||
| +--ro negotiated? label-adv-mode | |||||
| +--ro next-keep-alive? uint16 | |||||
| +--ro received-peer-state | |||||
| +--ro graceful-restart | |||||
| +--ro enabled? boolean | |||||
| +--ro reconnect-time? uint16 | |||||
| +--ro recovery-time? uint16 | |||||
| +--ro capability | |||||
| +--ro end-of-lib | |||||
| +--ro enabled? boolean | |||||
| +--ro typed-wildcard-fec | |||||
| +--ro enabled? boolean | |||||
| +--ro upstream-label-assignment | |||||
| +--ro enabled? boolean | |||||
| +--ro session-holdtime | |||||
| +--ro peer? uint16 | |||||
| +--ro negotiated? uint16 | |||||
| +--ro remaining? uint16 | |||||
| +--ro session-state? enumeration | |||||
| +--ro tcp-connection | |||||
| +--ro local-address? inet:ip-address | |||||
| +--ro local-port? inet:port-number | |||||
| +--ro remote-address? inet:ip-address | |||||
| +--ro remote-port? inet:port-number | |||||
| +--ro up-time? | |||||
| rt-types:timeticks64 | |||||
| +--ro statistics | |||||
| +--ro discontinuity-time yang:date-and-time | |||||
| +--ro received | |||||
| +--ro total-octets? yang:counter64 | |||||
| +--ro total-messages? yang:counter64 | |||||
| +--ro address? yang:counter64 | |||||
| +--ro address-withdraw? yang:counter64 | |||||
| +--ro initialization? yang:counter64 | |||||
| +--ro keepalive? yang:counter64 | |||||
| +--ro label-abort-request? yang:counter64 | |||||
| +--ro label-mapping? yang:counter64 | |||||
| +--ro label-release? yang:counter64 | |||||
| +--ro label-request? yang:counter64 | |||||
| +--ro label-withdraw? yang:counter64 | |||||
| +--ro notification? yang:counter64 | |||||
| +--ro sent | |||||
| +--ro total-octets? yang:counter64 | |||||
| +--ro total-messages? yang:counter64 | |||||
| +--ro address? yang:counter64 | |||||
| +--ro address-withdraw? yang:counter64 | |||||
| +--ro initialization? yang:counter64 | |||||
| +--ro keepalive? yang:counter64 | |||||
| +--ro label-abort-request? yang:counter64 | |||||
| +--ro label-mapping? yang:counter64 | |||||
| +--ro label-release? yang:counter64 | |||||
| +--ro label-request? yang:counter64 | |||||
| +--ro label-withdraw? yang:counter64 | |||||
| +--ro notification? yang:counter64 | |||||
| +--ro total-addresses? uint32 | |||||
| +--ro total-labels? uint32 | |||||
| +--ro total-fec-label-bindings? uint32 | |||||
| +--rw ldp-ext:admin-down? boolean | |||||
| {per-peer-admin-down}? | |||||
| +--rw ldp-ext:graceful-restart | |||||
| {per-peer-graceful-restart-config}? | |||||
| +--rw ldp-ext:enabled? boolean | |||||
| +--rw ldp-ext:reconnect-time? uint16 | |||||
| +--rw ldp-ext:recovery-time? uint16 | |||||
| +--rw ldp-ext:session-ka-holdtime? uint16 | |||||
| {per-peer-session-attributes-config}? | |||||
| +--rw ldp-ext:session-ka-interval? uint16 | |||||
| {per-peer-session-attributes-config}? |
+--rw ldp-ext:session-downstream-on-demand
| {session-downstream-on-demand-config}? |
|---|
| +--rw ldp-ext:enabled? boolean |
| +--rw ldp-ext:peer-list? peer-list-ref |
+--rw ldp-ext:dual-stack-transport-preference {peers-dual-stack-transport-preference}? +--rw ldp-ext:max-wait? uint16 +--rw ldp-ext:prefer-ipv4! +--rw ldp-ext:peer-list? peer-list-ref
rpcs: +---x mpls-ldp-clear-peer
| +---w input |
|---|
| +---w protocol-name? leafref |
| +---w lsr-id? leafref |
| +---w label-space-id? leafref |
+---x mpls-ldp-clear-hello-adjacency
| +---w input | |
|---|---|
| +---w hello-adjacency | |
| +---w protocol-name? leafref | |
| +---w (hello-adjacency-type)? | |
| +--:(targeted) | |
| +---w targeted! | |
| +---w target-address? inet:ip-address | |
| +--:(link) | |
| +---w link! | |
| +---w next-hop-interface? leafref | |
| +---w next-hop-address? inet:ip-address |
+---x mpls-ldp-clear-peer-statistics +---w input +---w protocol-name? leafref +---w lsr-id? leafref +---w label-space-id? leafref
notifications:
+---n mpls-ldp-peer-event
| +--ro event-type? oper-status-event-type
| +--ro peer
| +--ro protocol-name? leafref
| +--ro lsr-id? leafref
| +--ro label-space-id? leafref
+---n mpls-ldp-hello-adjacency-event
| +--ro event-type? oper-status-event-type
| +--ro protocol-name? leafref
| +--ro (hello-adjacency-type)?
| +--:(targeted)
| | +--ro targeted
| | +--ro target-address? inet:ip-address
| +--:(link)
| +--ro link
| +--ro next-hop-interface? if:interface-ref
| +--ro next-hop-address? inet:ip-address
+---n mpls-ldp-fec-event
+--ro event-type? oper-status-event-type
+--ro protocol-name? leafref
+--ro fec? inet:ip-prefix
Figure 2: Complete Tree5. Configuration 🎀
okay so this section is where we get into the config knobs 🔧 this spec defines the configuration parameters for base LDP, which is what [RFC5036] describes, and for LDP IPv6 [RFC7552] too 💖 it also bakes in support for LDP Capabilities [RFC5561] and lowkey goes ahead and defines some of the most important and commonly used capabilities, like Typed Wildcard FEC [RFC5918], End-of-LIB [RFC5919], and LDP Upstream Label Assignment [RFC6389] 🦋
this model augments /rt:routing/rt:control-plane-protocols/rt:control-plane-protocol, which is defined in [RFC8349] and follows NMDA, as we already mentioned 🌸
here's the high-level config organization for the base LDP module, so you can see the whole layout at a glance 👀
augment /rt:routing/rt:control-plane-protocols:
/rt:control-plane-protocol:
+-- mpls-ldp
+-- global
| +-- ...
| +-- ...
| +-- address-families
| | +-- ipv4
| | +-- . . .
| | +-- . . .
| +-- capability
| +-- ...
| +-- ...
+-- discovery
| +-- interfaces
| | +-- ...
| | +-- ...
| | +-- interface* [interface]
| | +-- ...
| | +-- address-families
| | +-- ipv4
| | +-- ...
| | +-- ...
| +-- targeted
| +-- ...
| +-- address-families
| +-- ipv4
| +-- target* [adjacent-address]
| +-- ...
| +-- ...
+-- peers
+-- ...
+-- ...
+-- peer* [lsr-id label-space-id]
+-- ...
+-- ...
Figure 3: Base Configuration Organizationand now the extended LDP module, which is the fancier glow-up 💅✨
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol
+-- mpls-ldp
+-- global
| +-- ...
| +-- ...
| +-- address-families
| | +-- ipv4
| | | +-- . . .
| | | +-- . . .
| | | +-- label-policy
| | | +-- ...
| | | +-- ...
| | +-- ipv6
| | +-- . . .
| | +-- . . .
| | +-- label-policy
| | +-- ...
| | +-- ...
| +-- capability
| | +-- ...
| | +-- ...
| +-- discovery
| +-- interfaces
| | +-- ...
| | +-- ...
| | +-- interface* [interface]
| | +-- ...
| | +-- address-families
| | +-- ipv4
| | | +-- ...
| | | +-- ...
| | +-- ipv6
| | +-- ...
| | +-- ...
| +-- targeted
| +-- ...
| +-- address-families
| +-- ipv6
| +- target* [adjacent-address]
| +- ...
| +- ...
+-- forwarding-nexthop
| +-- ...
| +-- ...
+-- peers
+-- ...
+-- ...
+-- peer*
+-- ...
+-- ...
+-- label-policy
| +-- ..
+-- address-families
+-- ipv4
| +-- ...
+-- ipv6
+-- ...
Figure 4: Extended Configuration Organizationthe cool part is inheritance 🧚 the model lets an item in a child tree pull its value from a similar or related item in one of its parents. for example, Hello holdtime can be set per VRF or per VRF interface, so you get inheritance AND the flexibility to override with a different value at any child level. that's giving main character energy 💜
5.1. Configuration Hierarchy 🌈
the LDP module lives under a network-instance, and the scope of any LDP config under this tree is per network-instance (per-VRF) 🏠 the config then splits into these sub categories:
- Global parameters
- Per-address-family parameters
- LDP Capabilities parameters
- Hello Discovery parameters
- interfaces
- Global
- Per-interface: Global
- Per-interface: Per-address-family
- targeted
- Global
- Per-address-family: Per-target
- interfaces
- Peer parameters
- Global
- Per-peer: Global
- Per-peer: Per-address-family
- Forwarding parameters
the next subsections briefly walk through each of these areas 🦋
5.1.1. Global Parameters 🌸
some config items sit directly under a VRF instance and don't fall under any other subtree. an example is the LDP LSR Id, which is typically configured per VRF 🆔 to keep legacy LDP features and applications working in an LDP IPv4 network with this model, this doc recommends that an operator pick a routable IPv4 unicast address (within a routing domain) as the LSR Id. that's the vibe 💅
5.1.2. Capabilities Parameters 🎀
this container lives under the global tree and holds the LDP capabilities that get enabled for certain features ✨ by default, an LDP capability is disabled unless it's explicitly enabled, so nothing sneaks on without you asking 🙈 these capabilities are typically used to negotiate with LDP peer(s) whether a feature and its parameters are supported or not. a capability enabled under this container applies to all LDP peers in the given VRF instance. there's also a peer-level capability container that lets you override a capability enabled or specified at the VRF level, which is a super useful escape hatch 🔥
5.1.3. Per-Address-Family Parameters 🌈
any LDP config parameter related to an IP address family (AF) whose scope is VRF-wide gets configured under this tree 🌐 examples of per-AF parameters include enabling LDP for an address family, prefix-list-based label policies, and the LDP transport address 💜
5.1.4. Hello Discovery Parameters 👂
this container holds the LDP config for the Hello and discovery process, for both basic (link) and extended (targeted) discovery 🔍
the interfaces container is where you configure parameters related to VRF interfaces 🔌 some parameters apply to all interfaces (like Hello timers), and some can be set per interface, so an interface list is defined under the interfaces container. the model defines parameters for per-interface non-AF-related items as well as per-interface per-AF items. an example of the former is interface Hello timers, and an example of the latter is enabling hellos for a given AF under an interface 🧁
the targeted container under a VRF instance is where you configure LDP targeted discovery parameters 🎯 inside it, the target list lets you configure multiple target addresses for extended discovery to a specific destination target, and also lets you fine-tune the per-target parameters 💖
5.1.5. Peer Parameters 🫶
this container holds the LDP config for LDP sessions and peers under a VRF instance 🤝 it lets you configure parameters that apply to all peers, or to a subset (peer-list) of them, in a given VRF. examples include authentication passwords, session KeepAlive (KA) timers, and so on. the model also allows per-peer parameter tuning by specifying a peer list under the peers container. a peer is uniquely identified by its LSR Id 🪪
just like per-interface parameters, some per-peer parameters are AF agnostic (meaning they're either non-AF related or apply to both IP address families), and some belong to an AF. the first kind is exemplified by a per-peer session password configuration, and the second by prefix-list-based label policies (inbound and outbound) that apply to a given peer 🍓
5.1.6. Forwarding Parameters 🚀
this container holds config used to control LDP forwarding behavior under a VRF instance 📦 one example is when a user wants to enable LDP neighbor discovery on an interface but wants to disable using that same interface for forwarding MPLS packets. that example only makes sense when there is more than one LDP-enabled interface towards a neighbor 🙃
6. Operational State 👑
okay now for the state side of things 📊 the operational state of LDP can be queried and obtained from read-only state containers under the same tree as the config, which is /rt:routing/rt:control-plane-protocols/rt:control-plane-protocol 🔎
the main areas where LDP operational state is defined are:
- Neighbor Adjacencies
- Peer
- Bindings (FEC-Label and address)
- Capabilities
6.1. Adjacency State 🦋
Okay bestie, neighbor adjacencies are per-address-family Hello adjacencies. They form with neighbors after LDP runs basic or extended discovery ✨ The organization goes like this: there's a source of discovery (an interface or a target address) with its own parameters, plus one or more discovered neighbors with their neighbor-discovery parameters.
With basic discovery, one source (interface) can have more than one discovered neighbor. Extended discovery is more exclusive, with at most one discovered neighbor per source (local-address and target-address) 💅 A targeted neighbor adjacency can come from either an active source (locally configured targeted) or a passive source (to allow any incoming extended/targeted hellos) 🎯 Each neighbor/adjacency record also holds session state that shows whether the adjacency has moved up to the session level or all the way to the peer level 🌸
Here's the high-level tree for neighbor adjacency state. It's shown for the ipv4 address-family only, but there's a similar tree for ipv6 too 🧚
+--rw mpls-ldp!
+--rw discovery
+--rw interfaces
| +--rw interface* [interface]
| +--rw address-families
| +--rw ipv4
| +--ro hello-adjacencies
| +--ro hello-adjacencies* [adjacent-address]
| +--ro adjacent-address
. . . .
. . . .
+--rw targeted
+--rw address-families
+--rw ipv4
+--ro hello-adjacencies
+--ro hello-adjacencies*
| [local-address adjacent-address]
+--ro local-address
+--ro adjacent-address
. . . .
. . . .
Figure 5: Adjacency State6.2. Peer State 💜
Peer state lives under a peers tree, and it's one of the core states 👑 It covers the session-related parameters (mode, authentication, KA timeout, etc.), the TCP connection info, the Hello adjacencies for the peer, statistics for messages and bindings, and capabilities exchange info. Main character energy, honestly 💅
Here's the high-level tree for peer state. The peer's Hello adjacencies tree is shown for ipv4 only, and a similar one exists for ipv6 🫶
+--rw mpls-ldp!
+--rw peers
+--rw peer* [lsr-id label-space-id]
+--rw lsr-id
+--rw label-space-id
+--ro label-advertisement-mode
+--ro session-state
+--ro tcp-connection
+--ro session-holdtime?
+--ro up-time
+-- . . . .
+--ro address-families
| +--ro ipv4
| +--ro hello-adjacencies
| +--ro hello-adjacencies*
| [local-address adjacent-address]
| . . . .
| . . . .
+--ro received-peer-state
| +--ro . . . .
| +--ro capability
| +--ro . . . .
+--ro statistics
+-- . . . .
+-- received
| +-- ...
+-- sent
+-- ...
Figure 6: Peer State6.3. Bindings State 🍓
Bindings state tells you about LDP FEC-Label bindings and address bindings, for both inbound (received) and outbound (advertised) directions 🔥 FEC-Label bindings get a FEC-centric view, and address bindings get an address-centric view. Here's an example:
FEC-Label bindings:
FEC 203.0.113.1/32:
advertised: local-label 16000
peer 192.0.2.1:0
peer 192.0.2.2:0
peer 192.0.2.3:0
received:
peer 192.0.2.1:0, label 16002, used-in-forwarding=Yes
peer 192.0.2.2:0, label 17002, used-in-forwarding=No
FEC 203.0.113.2/32:
. . . .
FEC 198.51.100.0/24:
. . . .
FEC 2001:db8:0:2::
. . . .
FEC 2001:db8:0:3::
. . . .
Address bindings:
Addr 192.0.2.10:
advertised
Addr 2001:db8:0:10::
advertised
Addr 192.0.2.1:
received, peer 192.0.2.1:0
Addr 192.0.2.2:
received, peer 192.0.2.2:0
Addr 192.0.2.3:
received, peer 192.0.2.3:0
Addr 2001:db8:0:2::
received, peer 192.0.2.2:0
Addr 2001:db8:0:3::
received, peer 192.0.2.3:0
Figure 7: Example BindingsNote that all local addresses are advertised to all peers 🌈 So there's no need for per-peer info on local address advertisement. Also, it's super easy to derive a peer-centric view from the info already in this model 🧠
The high-level tree for bindings state is next. It's shown for ipv4 only, with a similar tree for ipv6 🦋
+--rw mpls-ldp!
+--rw global
+--rw address-families
+--rw ipv4
+--ro bindings
+--ro address* [address]
| +--ro address (ipv4-address or ipv6-address)
| +--ro advertisement-type? advertised-received
| +--ro peer? leafref
+--ro fec-label* [fec]
+--ro fec (ipv4-prefix or ipv6-prefix)
+--ro peer* [peer advertisement-type]
+--ro peer leafref
+--ro advertisement-type? advertised-received
+--ro label? mpls:mpls-label
+--ro used-in-forwarding? boolean
Figure 8: Bindings State6.4. Capabilities State ✨
LDP capabilities state has two kinds of info: global info (like timers, etc.) and per-peer info 🎀
Here's the high-level tree for LDP capabilities state 🫶
+--rw mpls-ldp!
+--rw peers
+--rw peer* [lsr-id label-space-id]
+--rw lsr-id yang:dotted-quad
+--rw label-space-id
+--ro received-peer-state
+--ro capability
+--ro . . . .
+--ro . . . .
Figure 9: Capabilities State7. Notifications 🔔
This model defines a list of notifications that tell the client about important events during protocol operation 🚨 These events cover changes in the operational state of an LDP peer, a Hello adjacency, a FEC, and so on. Heads up: an LDP FEC counts as operational (up) as long as it has at least one Next Hop Label Forwarding Entry (NHLFE) with an outgoing label 💖
A simplified graphical representation of the data model for LDP notifications is shown in Figure 2.
8. Action 💅
This model defines a list of rpcs that let you perform an action or run a command on the protocol 🍓 For example, you can clear (reset) LDP peers, hello-adjacencies, and statistics. The model gives you different levels of control, so you can clear everything, clear everything of a given type, or clear one specific entity 🎯
A simplified graphical representation of the data model for LDP actions is shown in Figure 2.
9. YANG Specification 🧚
The following sections specify the actual YANG (module) specification for the LDP constructs defined earlier in the document 🌸
9.1. Base 💜
This YANG module imports types defined in [RFC6991], [RFC8177], [RFC8294], [RFC8343], [RFC8344], [RFC8349], and [RFC9067] 🦋
<CODE BEGINS> file "ietf-mpls-ldp@2022-03-14.yang"
module ietf-mpls-ldp {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-mpls-ldp";
prefix ldp;
import ietf-inet-types {
prefix inet;
reference
"RFC 6991: Common YANG Data Types";
}
import ietf-yang-types {
prefix yang;
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-routing-types {
prefix rt-types;
reference
"RFC 8294: Common YANG Data Types for the Routing Area";
}
import ietf-interfaces {
prefix if;
reference
"RFC 8343: A YANG Data Model for Interface Management";
}
import ietf-ip {
prefix ip;
reference
"RFC 8344: A YANG Data Model for IP Management";
}
import ietf-key-chain {
prefix key-chain;
reference
"RFC 8177: YANG Data Model for Key Chains";
}
organization
"IETF MPLS Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/mpls/>
WG List: <mailto:mpls@ietf.org>
Editor: Kamran Raza
<mailto:skraza@cisco.com>
Author: Rajiv Asati
<mailto:rajiva@cisco.com>
Author: Xufeng Liu
<mailto:xufeng.liu.ietf@gmail.com>
Author: Santosh Easale
<mailto:santosh_easale@berkeley.edu>
Author: Xia Chen
<mailto:jescia.chenxia@huawei.com>
Author: Himanshu Shah
<mailto:hshah@ciena.com>";
description
"This YANG module defines the essential components for the
management of Multiprotocol Label Switching (MPLS) Label
Distribution Protocol (LDP). It is also the base model to
be augmented for Multipoint LDP (mLDP).
Copyright (c) 2022 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 9070; see the
RFC itself for full legal notices.";
revision 2022-03-14 {
description
"Initial revision.";
reference
"RFC 9070: YANG Data Model for MPLS LDP";
}
/*
* Typedefs
*/
typedef advertised-received {
type enumeration {
enum advertised {
description
"Advertised information.";
}
enum received {
description
"Received information.";
}
}
description
"Received or advertised.";
}
typedef downstream-upstream {
type enumeration {
enum downstream {
description
"Downstream information.";
}
enum upstream {
description
"Upstream information.";
}
}
description
"Downstream or upstream.";
}typedef label-adv-mode { type enumeration { enum downstream-unsolicited { description "Downstream Unsolicited."; } enum downstream-on-demand { description "Downstream on Demand."; } } description "Label Advertisement Mode."; }
typedef oper-status-event-type { type enumeration { enum up { value 1; description "Operational status changed to up."; } enum down { value 2; description "Operational status changed to down."; } } description "Operational status event type for notifications."; }
/*
- Identities */
identity mpls-ldp { base rt:control-plane-protocol; description "LDP protocol."; reference "RFC 5036: LDP Specification"; }
identity adjacency-flag-base { description "Base type for adjacency flags."; }
identity adjacency-flag-active { base adjacency-flag-base; description "This adjacency is configured and actively created."; }
identity adjacency-flag-passive { base adjacency-flag-base; description "This adjacency is not configured and passively accepted."; }
/*
- Groupings */
grouping adjacency-state-attributes { description "The operational state attributes of an LDP Hello adjacency, which can used for basic and extended discoveries, in IPv4 and IPv6 address families."; leaf-list flag { type identityref { base adjacency-flag-base; } description "One or more flags to indicate whether the adjacency is actively created, passively accepted, or both."; } container hello-holdtime { description "Containing Hello holdtime state information."; leaf adjacent { type uint16; units "seconds"; description "The holdtime value learned from the adjacent LSR."; } leaf negotiated { type uint16; units "seconds"; description "The holdtime negotiated between this LSR and the adjacent LSR."; } leaf remaining { type uint16; units "seconds"; description "The time remaining until the holdtime timer expires."; } } leaf next-hello { type uint16; units "seconds"; description "The time when the next Hello message will be sent."; } container statistics { description "Statistics objects."; leaf discontinuity-time { type yang:date-and-time; mandatory true; description "The time on the most recent occasion at which any one or more of this interface's counters suffered a discontinuity. If no such discontinuities have occurred since the last re-initialization of the local management subsystem, then this node contains the time the local management subsystem re-initialized itself."; } leaf hello-received { type yang:counter64; description "The number of Hello messages received."; } leaf hello-dropped { type yang:counter64; description "The number of Hello messages dropped."; } } // statistics } // adjacency-state-attributes
grouping basic-discovery-timers { description "The timer attributes for basic discovery, used in the per-interface setting and in the all-interface setting."; leaf hello-holdtime { type uint16 { range "15..3600"; } units "seconds"; description "The time interval for which an LDP link Hello adjacency is maintained in the absence of link Hello messages from the LDP neighbor. This leaf may be configured at the per-interface level or the global level, with precedence given to the value at the per-interface level. If the leaf is not configured at either level, the default value at the global level is used."; } leaf hello-interval { type uint16 { range "5..1200"; } units "seconds"; description "The interval between consecutive LDP link Hello messages used in basic LDP discovery. This leaf may be configured at the per-interface level or the global level, with precedence given to the value at the per-interface level. If the leaf is not configured at either level, the default value at the global level is used."; } } // basic-discovery-timers
grouping binding-address-state-attributes { description "Operational state attributes of an address binding, used in IPv4 and IPv6 address families."; leaf advertisement-type { type advertised-received; description "Received or advertised."; } container peer { when "../advertisement-type = 'received'" { description "Applicable for received address."; } description "LDP peer from which this address is received."; uses ldp-peer-ref-from-binding; } } // binding-address-state-attributes
grouping binding-label-state-attributes { description "Operational state attributes for a FEC-Label binding, used in IPv4 and IPv6 address families."; list peer { key "lsr-id label-space-id advertisement-type"; description "List of advertised and received peers."; uses ldp-peer-ref-from-binding { description "The LDP peer from which this binding is received, or to which this binding is advertised. The peer is identified by its LDP ID, which consists of the LSR Id and the label space Id."; } leaf advertisement-type { type advertised-received; description "Received or advertised."; } leaf label { type rt-types:mpls-label; description "Advertised (outbound) or received (inbound) label."; } leaf used-in-forwarding { type boolean; description "'true' if the label is used in forwarding."; } } // peer } // binding-label-state-attributes
grouping graceful-restart-attributes-per-peer { description "Per-peer graceful restart attributes. On the local side, these attributes are configuration and operational state data. On the peer side, these attributes are operational state data received from the peer."; container graceful-restart { description "Attributes for graceful restart."; leaf enabled { type boolean; description "Enable or disable graceful restart. This leaf may be configured at the per-peer level or the global level, with precedence given to the value at the per-peer level. If the leaf is not configured at either level, the default value at the global level is used."; } leaf reconnect-time { type uint16 { range "10..1800"; } units "seconds"; description "Specifies the time interval that the remote LDP peer must wait for the local LDP peer to reconnect after the remote peer detects the LDP communication failure. This leaf may be configured at the per-peer level or the global level, with precedence given to the value at the per-peer level. If the leaf is not configured at either level, the default value at the global level is used."; } leaf recovery-time { type uint16 { range "30..3600"; } units "seconds"; description "Specifies the time interval, in seconds, that the remote LDP peer preserves its MPLS forwarding state after receiving the Initialization message from the restarted local LDP peer. This leaf may be configured at the per-peer level or the global level, with precedence given to the value at the per-peer level. If the leaf is not configured at either level, the default value at the global level is used."; } } // graceful-restart } // graceful-restart-attributes-per-peer
grouping ldp-interface-ref { description "Defining a reference to an LDP interface."; leaf name { type if:interface-ref; must '(/if:interfaces/if:interface[if:name=current()]/ip:ipv4)'
- ' or '
- '(/if:interfaces/if:interface[if:name=current()]/ip:ipv6)' { description "Interface is IPv4 or IPv6."; } description "The name of an LDP interface."; } }
grouping ldp-peer-ref-absolute { description "An absolute reference to an LDP peer, by the LDP ID, which consists of the LSR Id and the label space Id."; leaf protocol-name { type leafref { path "/rt:routing/rt:control-plane-protocols/"
- "rt:control-plane-protocol/rt:name"; } description "The name of the LDP protocol instance."; } leaf lsr-id { type leafref { path "/rt:routing/rt:control-plane-protocols/"
- "rt:control-plane-protocol"
- "[rt:name=current()/../protocol-name]/"
- "ldp:mpls-ldp/ldp:peers/ldp:peer/ldp:lsr-id"; } description "The LSR Id of the peer, as a portion of the peer LDP ID."; } leaf label-space-id { type leafref { path "/rt:routing/rt:control-plane-protocols/"
- "rt:control-plane-protocol"
- "[rt:name=current()/../protocol-name]/"
- "ldp:mpls-ldp/ldp:peers/"
- "ldp:peer[ldp:lsr-id=current()/../lsr-id]/"
- "ldp:label-space-id"; } description "The label space Id of the peer, as a portion of the peer LDP ID."; } } // ldp-peer-ref-absolute
grouping ldp-peer-ref-from-binding { description "A relative reference to an LDP peer, by the LDP ID, which consists of the LSR Id and the label space Id."; leaf lsr-id { type leafref { path "../../../../../../../ldp:peers/ldp:peer/ldp:lsr-id"; } description "The LSR Id of the peer, as a portion of the peer LDP ID."; } leaf label-space-id { type leafref { path "../../../../../../../ldp:peers/"
- "ldp:peer[ldp:lsr-id=current()/../lsr-id]/"
- "ldp:label-space-id"; } description "The label space Id of the peer, as a portion of the peer LDP ID."; } } // ldp-peer-ref-from-binding
okay bestie, we're still inside the YANG module 💖 Let's keep going with the peer references, the attributes, and the state groupings 🎀
grouping ldp-peer-ref-from-interface {
description
"A relative reference to an LDP peer, by the LDP ID, which
consists of the LSR Id and the label space Id.";
container peer {
description
"Reference to an LDP peer, by the LDP ID, which consists of
the LSR Id and the label space Id.";
leaf lsr-id {
type leafref {
path "../../../../../../../../../ldp:peers/ldp:peer/"
+ "ldp:lsr-id";
}
description
"The LSR Id of the peer, as a portion of the peer LDP ID.";
}
leaf label-space-id {
type leafref {
path "../../../../../../../../../ldp:peers/"
+ "ldp:peer[ldp:lsr-id=current()/../lsr-id]/"
+ "ldp:label-space-id";
}
description
"The label space Id of the peer, as a portion of the peer
LDP ID.";
}
} // peer
} // ldp-peer-ref-from-interface
grouping ldp-peer-ref-from-target {
description
"A relative reference to an LDP peer, by the LDP ID, which
consists of the LSR Id and the label space Id.";
container peer {
description
"Reference to an LDP peer, by the LDP ID, which consists of
the LSR Id and the label space Id.";
leaf lsr-id {
type leafref {
path "../../../../../../../../ldp:peers/ldp:peer/"
+ "ldp:lsr-id";
}
description
"The LSR Id of the peer, as a portion of the peer LDP ID.";
}
leaf label-space-id {
type leafref {
path "../../../../../../../../ldp:peers/"
+ "ldp:peer[ldp:lsr-id=current()/../lsr-id]/"
+ "ldp:label-space-id";
}
description
"The label space Id of the peer, as a portion of the peer
LDP ID.";
}
} // peer
} // ldp-peer-ref-from-target
grouping peer-attributes {
description
"Peer configuration attributes, used in the per-peer setting
can in the all-peer setting.";
leaf session-ka-holdtime {
type uint16 {
range "45..3600";
}
units "seconds";
description
"The time interval after which an inactive LDP session
terminates and the corresponding TCP session closes.
Inactivity is defined as not receiving LDP packets from the
peer.
This leaf may be configured at the per-peer level or the
global level, with precedence given to the value at the
per-peer level. If the leaf is not configured at either
level, the default value at the global level is used.";
}
leaf session-ka-interval {
type uint16 {
range "15..1200";
}
units "seconds";
description
"The interval between successive transmissions of KeepAlive
packets. Keepalive packets are only sent in the absence of
other LDP packets transmitted over the LDP session.
This leaf may be configured at the per-peer level or the
global level, with precedence given to the value at the
per-peer level. If the leaf is not configured at either
level, the default value at the global level is used.";
}
} // peer-attributes
grouping peer-authentication {
description
"Peer authentication container, used in the per-peer setting
can in the all-peer setting.";
container authentication {
description
"Containing authentication information.";
choice authentication-type {
description
"Choice of authentication.";
case password {
leaf key {
type string;
description
"This leaf specifies the authentication key. The
length of the key may be dependent on the
cryptographic algorithm.";
}
leaf crypto-algorithm {
type identityref {
base key-chain:crypto-algorithm;
}
description
"Cryptographic algorithm associated with key.";
}
}
}
}
} // peer-authentication
grouping peer-state-derived {
description
"The peer state information derived from the LDP protocol
operations.";
container label-advertisement-mode {
config false;
description
"Label advertisement mode state.";
leaf local {
type label-adv-mode;
description
"Local Label Advertisement Mode.";
}
leaf peer {
type label-adv-mode;
description
"Peer Label Advertisement Mode.";
}
leaf negotiated {
type label-adv-mode;
description
"Negotiated Label Advertisement Mode.";
}
}
leaf next-keep-alive {
type uint16;
units "seconds";
config false;
description
"Time duration from now until sending the next KeepAlive
message.";
}
container received-peer-state {
config false;
description
"Operational state information learned from the peer.";
uses graceful-restart-attributes-per-peer;
container capability {
description
"Peer capability information.";
container end-of-lib {
description
"Peer's end-of-lib capability.";
leaf enabled {
type boolean;
description
"'true' if peer's end-of-lib capability is enabled.";
}
}
container typed-wildcard-fec {
description
"Peer's typed-wildcard-fec capability.";
leaf enabled {
type boolean;
description
"'true' if peer's typed-wildcard-fec capability is
enabled.";
}
}
container upstream-label-assignment {
description
"Peer's upstream label assignment capability.";
leaf enabled {
type boolean;
description
"'true' if peer's upstream label assignment is
enabled.";
}
}
} // capability
} // received-peer-state
container session-holdtime {
config false;
description
"Session holdtime state.";
leaf peer {
type uint16;
units "seconds";
description
"Peer holdtime.";
}
leaf negotiated {
type uint16;
units "seconds";
description
"Negotiated holdtime.";
}
leaf remaining {
type uint16;
units "seconds";
description
"Remaining holdtime.";
}
} // session-holdtime
leaf session-state {
type enumeration {
enum non-existent {
description
"NON EXISTENT state. Transport disconnected.";
}
enum initialized {
description
"INITIALIZED state.";
}
enum openrec {
description
"OPENREC state.";
}
enum opensent {
description
"OPENSENT state.";
}
enum operational {
description
"OPERATIONAL state.";
}
}
config false;
description
"Representing the operational status of the LDP session.";
reference
"RFC 5036: LDP Specification, Sec. 2.5.4.";
}
container tcp-connection {
config false;
description
"TCP connection state.";
leaf local-address {
type inet:ip-address;
description
"Local address.";
}
leaf local-port {
type inet:port-number;
description
"Local port number.";
}
leaf remote-address {
type inet:ip-address;
description
"Remote address.";
}
leaf remote-port {
type inet:port-number;
description
"Remote port number.";
}
} // tcp-connection
leaf up-time {
type rt-types:timeticks64;
config false;
description
"The number of time ticks (hundredths of a second) since the
state of the session with the peer changed to
OPERATIONAL.";
}
container statistics {
config false;
description
"Statistics objects.";
leaf discontinuity-time {
type yang:date-and-time;
mandatory true;
description
"The time on the most recent occasion at which any one or
more of this interface's counters suffered a
discontinuity. If no such discontinuities have occurred
since the last re-initialization of the local management
subsystem, then this node contains the time the local
management subsystem re-initialized itself.";
}
container received {
description
"Inbound statistics.";
uses statistics-peer-received-sent;
}
container sent {
description
"Outbound statistics.";
uses statistics-peer-received-sent;
}
leaf total-addresses {
type uint32;
description
"The number of learned addresses.";
}
leaf total-labels {
type uint32;
description
"The number of learned labels.";
}
leaf total-fec-label-bindings {
type uint32;
description
"The number of learned label-address bindings.";
}
} // statistics
} // peer-state-derivedthe peer-attributes grouping is where the keepalive timers live, and they're giving precedence drama: per-peer always beats global 👑
peer-authentication is the password case, with the key and the crypto-algorithm both lowkey tucked inside the choice 🔐
peer-state-derived is the whole vibe check on the live session: label advertisement modes, holdtimes, TCP details, uptime and stats 🦋✨
okay so this part is all about the stats counters for peer messages, and they're giving detailed 💅 every single one tracks sent or received messages by type, plus a total for octets and messages. let's gooo 🦋
grouping statistics-peer-received-sent {
description
"Inbound and outbound statistic counters.";
leaf total-octets {
type yang:counter64;
description
"The total number of octets sent or received.";
}
leaf total-messages {
type yang:counter64;
description
"The number of messages sent or received.";
}
leaf address {
type yang:counter64;
description
"The number of Address messages sent or received.";
}
leaf address-withdraw {
type yang:counter64;
description
"The number of address-withdraw messages sent or received.";
}
leaf initialization {
type yang:counter64;
description
"The number of Initialization messages sent or received.";
}
leaf keepalive {
type yang:counter64;
description
"The number of KeepAlive messages sent or received.";
}
leaf label-abort-request {
type yang:counter64;
description
"The number of label-abort-request messages sent or
received.";
}
leaf label-mapping {
type yang:counter64;
description
"The number of label-mapping messages sent or received.";
}
leaf label-release {
type yang:counter64;
description
"The number of label-release messages sent or received.";
}
leaf label-request {
type yang:counter64;
description
"The number of label-request messages sent or received.";
}
leaf label-withdraw {
type yang:counter64;
description
"The number of label-withdraw messages sent or received.";
}
leaf notification {
type yang:counter64;
description
"The number of notification messages sent or received.";
}
} // statistics-peer-received-sent
/*
* Configuration data and operational state data nodes
*/okay bestie, this is where the LDP augmentation gets spicy 🌶️ It plugs LDP config and state into the routing control-plane protocol list, but only for instances whose type is mpls-ldp, and only one of those is allowed per router 💅✨
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol" {
when "derived-from-or-self(rt:type, 'ldp:mpls-ldp')" {
description
"This augmentation is only valid for a control plane
protocol instance of LDP (type 'mpls-ldp').";
}
description
"LDP augmentation to routing control plane protocol
configuration and state.";
container mpls-ldp {
must "not (../../rt:control-plane-protocol"
+ "[derived-from-or-self(rt:type, 'ldp:mpls-ldp')]"
+ "[rt:name!=current()/../rt:name])" {
description
"Only one LDP instance is allowed.";
}
description
"Containing configuration and operational data for the LDP
protocol.";
container global {
description
"Global attributes for LDP.";
container capability {
description
"Containing the LDP capability data. The container is
used for augmentations.";
reference
"RFC 5036: LDP Specification, Sec. 1.5.";
}
container graceful-restart {
description
"Attributes for graceful restart.";
leaf enabled {
type boolean;
default "false";
description
"Enable or disable graceful restart.";
}
leaf reconnect-time {
type uint16 {
range "10..1800";
}
units "seconds";
default "120";
description
"Specifies the time interval that the remote LDP peer
must wait for the local LDP peer to reconnect after
the remote peer detects the LDP communication
failure.";
}
leaf recovery-time {
type uint16 {
range "30..3600";
}
units "seconds";
default "120";
description
"Specifies the time interval, in seconds, that the
remote LDP peer preserves its MPLS forwarding state
after receiving the Initialization message from the
restarted local LDP peer.";
}
leaf forwarding-holdtime {
type uint16 {
range "30..3600";
}
units "seconds";
default "180";
description
"Specifies the time interval, in seconds, before the
termination of the recovery phase.";
}
} // graceful-restart
leaf lsr-id {
type rt-types:router-id;
description
"Specifies the value to act as the LDP LSR Id.
If this attribute is not specified, LDP uses the router
ID as determined by the system.";
}
container address-families {
description
"Per-address-family configuration and operational state.
The address family can be either IPv4 or IPv6.";
container ipv4 {
presence "Present if IPv4 is enabled, unless the
'enabled' leaf is set to 'false'.";
description
"Containing data related to the IPv4 address family.";
leaf enabled {
type boolean;
default "true";
description
"'false' to disable the address family.";
}
leaf label-distribution-control-mode {
type enumeration {
enum independent {
description
"Independent label distribution control.";
}
enum ordered {
description
"Ordered label distribution control.";
}
}
config false;
description
"Label distribution control mode.";
reference
"RFC 5036: LDP Specification, Sec. 2.6.";
}
// ipv4 bindings
container bindings {
config false;
description
"LDP address and label binding information.";
list address {
key "address";
description
"List of address bindings learned by LDP.";
leaf address {
type inet:ipv4-address;
description
"The IPv4 address learned from an Address
message received from or advertised to a peer.";
}
uses binding-address-state-attributes;
}
list fec-label {
key "fec";
description
"List of FEC-label bindings learned by LDP.";
leaf fec {
type inet:ipv4-prefix;
description
"The prefix FEC value in the FEC-Label binding,
learned in a Label Mapping message received from
or advertised to a peer.";
}
uses binding-label-state-attributes;
}
} // bindings
} // ipv4
} // address-families
} // global
container discovery {
description
"Neighbor-discovery configuration and operational state.";
container interfaces {
description
"A list of interfaces for LDP Basic Discovery.";
reference
"RFC 5036: LDP Specification, Sec. 2.4.1.";
uses basic-discovery-timers {
refine "hello-holdtime" {
default "15";
}
refine "hello-interval" {
default "5";
}
}
list interface {
key "name";
description
"List of LDP interfaces used for LDP Basic Discovery.";
uses ldp-interface-ref;
leaf next-hello {
type uint16;
units "seconds";
config false;
description
"Time to send the next Hello message.";
}
container address-families {
description
"Container for address families.";
container ipv4 {
presence "Present if IPv4 is enabled, unless the
'enabled' leaf is set to 'false'.";
description
"IPv4 address family.";
leaf enabled {
type boolean;
default "true";
description
"Set to false to disable the address family on
the interface.";
}
container hello-adjacencies {
config false;
description
"Containing a list of Hello adjacencies.";
list hello-adjacency {
key "adjacent-address";
config false;
description
"List of Hello adjacencies.";
leaf adjacent-address {
type inet:ipv4-address;
description
"Neighbor address of the Hello adjacency.";
}
uses adjacency-state-attributes;
uses ldp-peer-ref-from-interface;
}
}
} // ipv4
} // address-families
} // interface
} // interfaces
container targeted {
description
"A list of targeted neighbors for extended discovery.";
leaf hello-holdtime {
type uint16 {
range "15..3600";
}
units "seconds";
default "45";
description
"The time interval for which an LDP targeted Hello
adjacency is maintained in the absence of targeted
Hello messages from an LDP neighbor.";
}
leaf hello-interval {
type uint16 {
range "5..3600";
}
units "seconds";
default "15";
description
"The interval between consecutive LDP targeted Hello
messages used in extended LDP discovery.";
}
container hello-accept {
description
"LDP policy to control the acceptance of extended
neighbor-discovery Hello messages.";
leaf enabled {
type boolean;
default "false";
description
"'true' to accept; 'false' to deny.";
}
}
container address-families {
description
"Container for address families.";
container ipv4 {
presence "Present if IPv4 is enabled.";
description
"IPv4 address family.";
container hello-adjacencies {
config false;
description
"Containing a list of Hello adjacencies.";
list hello-adjacency {
key "local-address adjacent-address";
description
"List of Hello adjacencies.";
leaf local-address {
type inet:ipv4-address;
description
"Local address of the Hello adjacency.";
}
leaf adjacent-address {
type inet:ipv4-address;
description
"Neighbor address of the Hello adjacency.";
}
uses adjacency-state-attributes;
uses ldp-peer-ref-from-target;
}
}
list target {
key "adjacent-address";
description
"Targeted discovery params.";
leaf adjacent-address {
type inet:ipv4-address;
description
"Configures a remote LDP neighbor for the
extended LDP discovery.";
}
leaf enabled {
type boolean;
default "true";
description
"'true' to enable the target.";
}
leaf local-address {
type inet:ipv4-address;
description
"The local address used as the source address to
send targeted Hello messages.
If the value is not specified, the
transport address is used as the source
address.";
}
} // target
} // ipv4
} // address-families
} // targeted
} // discoverycontainer peers { description "Peers configuration attributes."; uses peer-authentication; uses peer-attributes { refine "session-ka-holdtime" { default "180"; } refine "session-ka-interval" { default "60"; } } list peer { key "lsr-id label-space-id"; description "List of peers."; leaf lsr-id { type rt-types:router-id; description "The LSR Id of the peer, used to identify the globally unique LSR. This is the first four octets of the LDP ID. This leaf is used together with the leaf 'label-space-id' to form the LDP ID."; reference "RFC 5036: LDP Specification, Sec. 2.2.2."; } leaf label-space-id { type uint16; description "The label space Id of the peer, used to identify a specific label space within the LSR. This is the last two octets of the LDP ID. This leaf is used together with the leaf 'lsr-id' to form the LDP ID."; reference "RFC 5036: LDP Specification, Sec. 2.2.2."; } uses peer-authentication; container address-families { description "Per-vrf per-af params."; container ipv4 { presence "Present if IPv4 is enabled."; description "IPv4 address family."; container hello-adjacencies { config false; description "Containing a list of Hello adjacencies."; list hello-adjacency { key "local-address adjacent-address"; description "List of Hello adjacencies."; leaf local-address { type inet:ipv4-address; description "Local address of the Hello adjacency."; } leaf adjacent-address { type inet:ipv4-address; description "Neighbor address of the Hello adjacency."; } uses adjacency-state-attributes; leaf interface { type if:interface-ref; description "Interface for this adjacency."; } } } } // ipv4 } // address-families uses peer-state-derived; } // list peer } // peers } // container mpls-ldp }
/*
- RPCs */
rpc mpls-ldp-clear-peer { description "Clears the session to the peer."; input { uses ldp-peer-ref-absolute { description "The LDP peer to be cleared. If this is not provided, then all peers are cleared. The peer is identified by its LDP ID, which consists of the LSR Id and the label space Id."; } } }
rpc mpls-ldp-clear-hello-adjacency { description "Clears the Hello adjacency."; input { container hello-adjacency { description "Link adjacency or targeted adjacency. If this is not provided, then all Hello adjacencies are cleared."; leaf protocol-name { type leafref { path "/rt:routing/rt:control-plane-protocols/"
- "rt:control-plane-protocol/rt:name"; } description "The name of the LDP protocol instance."; } choice hello-adjacency-type { description "Adjacency type."; case targeted { container targeted { presence "Present to clear targeted adjacencies."; description "Clear targeted adjacencies."; leaf target-address { type inet:ip-address; description "The target address. If this is not provided, then all targeted adjacencies are cleared."; } } } case link { container link { presence "Present to clear link adjacencies."; description "Clear link adjacencies."; leaf next-hop-interface { type leafref { path "/rt:routing/rt:control-plane-protocols/"
- "rt:control-plane-protocol/mpls-ldp/"
- "discovery/interfaces/interface/name"; } description "Interface connecting to a next hop. If this is not provided, then all link adjacencies are cleared."; } leaf next-hop-address { type inet:ip-address; must '../next-hop-interface' { description "Applicable when an interface is specified."; } description "IP address of a next hop. If this is not provided, then adjacencies to all next hops on the given interface are cleared."; } } } } // hello-adjacency-type } // hello-adjacency } // input } // mpls-ldp-clear-hello-adjacency
rpc mpls-ldp-clear-peer-statistics { description "Clears protocol statistics (e.g., sent and received counters)."; input { uses ldp-peer-ref-absolute { description "The LDP peer whose statistics are to be cleared. If this is not provided, then all peers' statistics are cleared. The peer is identified by its LDP ID, which consists of the LSR Id and the label space Id."; } } }
/*
- Notifications */
notification mpls-ldp-peer-event { description "Notification event for a change of LDP peer operational status."; leaf event-type { type oper-status-event-type; description "Event type."; } container peer { description "Reference to an LDP peer, by the LDP ID, which consists of the LSR Id and the label space Id."; uses ldp-peer-ref-absolute; } }
notification mpls-ldp-hello-adjacency-event { description "Notification event for a change of LDP adjacency operational status."; leaf event-type { type oper-status-event-type; description "Event type."; } leaf protocol-name { type leafref { path "/rt:routing/rt:control-plane-protocols/"
- "rt:control-plane-protocol/rt:name"; } description "The name of the LDP protocol instance."; } choice hello-adjacency-type { description "Interface or targeted adjacency."; case targeted { container targeted { description "Targeted adjacency through LDP extended discovery."; leaf target-address { type inet:ip-address; description "The target adjacent-address learned."; } } } case link { container link { description "Link adjacency through LDP basic discovery."; leaf next-hop-interface { type if:interface-ref; description "The interface connecting to the adjacent next hop."; } leaf next-hop-address { type inet:ip-address; must '../next-hop-interface' { description "Applicable when an interface is specified."; } description "IP address of the next hop. This can be IPv4 or IPv6 address."; } } } } // hello-adjacency-type } // mpls-ldp-hello-adjacency-event
notification mpls-ldp-fec-event { description "Notification event for a change of FEC status."; leaf event-type { type oper-status-event-type; description "Event type."; } leaf protocol-name { type leafref { path "/rt:routing/rt:control-plane-protocols/"
- "rt:control-plane-protocol/rt:name"; } description "The name of the LDP protocol instance."; } leaf fec { type inet:ip-prefix; description "The address prefix element of the FEC whose status has changed."; } } } <CODE ENDS>
Figure 10: LDP Base Module
9.2. Extended ✨
okay bestie, this one's a whole mood 🎀 This YANG module imports types defined in [RFC5036], [RFC6991], [RFC8349], [RFC8177], [RFC8343], and [RFC9067] 💅
<CODE BEGINS> file "ietf-mpls-ldp-extended@2022-03-14.yang"
module ietf-mpls-ldp-extended {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-mpls-ldp-extended";
prefix ldp-ext;
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-key-chain {
prefix key-chain;
reference
"RFC 8177: YANG Data Model for Key Chains";
}
import ietf-mpls-ldp {
prefix ldp;
reference
"RFC 9070: YANG Data Model for MPLS LDP";
}
import ietf-interfaces {
prefix if;
reference
"RFC 8343: A YANG Data Model for Interface Management";
}
import ietf-routing-policy {
prefix rt-pol;
reference
"RFC 9067: A YANG Data Model for Routing Policy";
}
organization
"IETF MPLS Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/mpls/>
WG List: <mailto:mpls@ietf.org>
Editor: Kamran Raza
<mailto:skraza@cisco.com>
Author: Rajiv Asati
<mailto:rajiva@cisco.com>
Author: Xufeng Liu
<mailto:xufeng.liu.ietf@gmail.com>
Author: Santosh Easale
<mailto:santosh_easale@berkeley.edu>
Author: Xia Chen
<mailto:jescia.chenxia@huawei.com>
Author: Himanshu Shah
<mailto:hshah@ciena.com>";
description
"This YANG module defines the extended components for the
management of Multiprotocol Label Switching (MPLS) Label
Distribution Protocol (LDP). It is also the model to
be augmented for extended Multipoint LDP (mLDP).
Copyright (c) 2022 IETF Trust and the persons identified as
authors of the code. All rights reserved.Okay bestie, the YANG features list is literally giving menu 💅✨ Here's the rest of the module, exactly as the spec has it 🎀
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 9070; see the
RFC itself for full legal notices.";
revision 2022-03-14 {
description
"Initial revision.";
reference
"RFC 9070: YANG Data Model for MPLS LDP";
}
/*
* Features
*/
feature capability-end-of-lib {
description
"This feature indicates that the system allows for the
configuration of LDP end-of-lib capability.";
}
feature capability-typed-wildcard-fec {
description
"This feature indicates that the system allows for the
configuration of LDP typed-wildcard-fec capability.";
}
feature capability-upstream-label-assignment {
description
"This feature indicates that the system allows for the
configuration of LDP upstream label assignment capability.";
}
feature forwarding-nexthop-config {
description
"This feature indicates that the system allows for controlling
MPLS forwarding on an LDP interface.";
}
feature graceful-restart-helper-mode {
description
"This feature indicates that the system supports graceful
restart helper mode. We call an LSR to be operating in GR
helper mode when it advertises 0 as its FT Reconnect Timeout
in the FT Session TLV.
Please refer to Section 2 of RFC 3478 for details.";
}
feature key-chain {
description
"This feature indicates that the system supports key-chain for
authentication.";
}
feature peers-dual-stack-transport-preference {
description
"This feature indicates that the system allows for the
configuration of the transport connection preference in a
dual-stack setup for peers.";
}
feature per-interface-timer-config {
description
"This feature indicates that the system allows for the
configuration of interface Hello timers at the per-interface
level.";
}
feature per-peer-admin-down {
description
"This feature indicates that the system allows for the
administrative disabling of a peer.";
}
feature per-peer-graceful-restart-config {
description
"This feature indicates that the system allows for the
configuration of graceful restart at the per-peer level.";
}
feature per-peer-session-attributes-config {
description
"This feature indicates that the system allows for the
configuration of session attributes at the per-peer level.";
}
feature policy-label-assignment-config {
description
"This feature indicates that the system allows for the
configuration of policies to assign labels according to
certain prefixes.";
}
feature policy-ordered-label-config {
description
"This feature indicates that the system allows for the
configuration of ordered label policies.";
}
feature policy-targeted-discovery-config {
description
"This feature indicates that the system allows for the
configuration of policies to control the acceptance of
targeted neighbor-discovery Hello messages.";
}
feature session-downstream-on-demand-config {
description
"This feature indicates that the system allows for the
configuration of session downstream on demand.";
}
/*
* Typedefs
*/
typedef neighbor-list-ref {
type leafref {
path "/rt-pol:routing-policy/rt-pol:defined-sets/"
+ "rt-pol:neighbor-sets/rt-pol:neighbor-set/rt-pol:name";
}
description
"A type for a reference to a neighbor address list.
The string value is the name identifier for uniquely
identifying the referenced address list, which contains a list
of addresses that a routing policy can applied.";
reference
"RFC 9067: A YANG Data Model for Routing Policy";
}
typedef prefix-list-ref {
type leafref {
path "/rt-pol:routing-policy/rt-pol:defined-sets/"
+ "rt-pol:prefix-sets/rt-pol:prefix-set/rt-pol:name";
}
description
"A type for a reference to a prefix list.
The string value is the name identifier for uniquely
identifying the referenced prefix set, which contains a list
of prefixes that a routing policy can applied.";
reference
"RFC 9067: A YANG Data Model for Routing Policy";
}
typedef peer-list-ref {
type leafref {
path "/rt-pol:routing-policy/rt-pol:defined-sets/"
+ "rt-pol:neighbor-sets/rt-pol:neighbor-set/rt-pol:name";
}
description
"A type for a reference to a peer address list.
The string value is the name identifier for uniquely
identifying the referenced address list, which contains a list
of addresses that a routing policy can applied.";
reference
"RFC 9067: A YANG Data Model for Routing Policy";
}
/*
* Identities
*/
/*
* Groupings
*/
grouping address-family-ipv4-augment {
description
"Augmentation to address family IPv4.";
uses policy-container;
leaf transport-address {
type inet:ipv4-address;
description
"The transport address advertised in LDP Hello messages.
If this value is not specified, the LDP LSR Id is used as
the transport address.";
reference
"RFC 5036: LDP Specification, Sec. 3.5.2.";
}
}
grouping authentication-keychain-augment {
description
"Augmentation to authentication to add key-chain.";
leaf key-chain {
type key-chain:key-chain-ref;
description
"key-chain name.
If not specified, no key chain is used.";
}
}
grouping capability-augment {
description
"Augmentation to capability.";
container end-of-lib {
if-feature "capability-end-of-lib";
description
"Configure end-of-lib capability.";
leaf enabled {
type boolean;
default "false";
description
"'true' to enable end-of-lib capability.";
}
}
container typed-wildcard-fec {
if-feature "capability-typed-wildcard-fec";
description
"Configure typed-wildcard-fec capability.";
leaf enabled {
type boolean;
default "false";
description
"'true' to enable typed-wildcard-fec capability.";
}
}
container upstream-label-assignment {
if-feature "capability-upstream-label-assignment";
description
"Configure upstream label assignment capability.";
leaf enabled {
type boolean;
default "false";
description
"'true' to enable upstream label assignment.";
}
}
} // capability-augment
grouping global-augment {
description
"Augmentation to global attributes.";
leaf igp-synchronization-delay {
type uint16 {
range "0 | 3..300";
}
units "seconds";
default "0";
description
"Sets the interval that the LDP waits before notifying the
Interior Gateway Protocol (IGP) that label exchange is
completed so that IGP can start advertising the normal
metric for the link.
If the value is not specified, there is no delay.";
}
}
grouping global-forwarding-nexthop-augment {
description
"Augmentation at the global level for controlling MPLS
forwarding on LDP interfaces.";
container forwarding-nexthop {
if-feature "forwarding-nexthop-config";
description
"Configuration for controlling MPLS forwarding on LDP
interfaces.";
container interfaces {
description
"Containing a list of interfaces on which forwarding can be
disabled.";
list interface {
key "name";
description
"List of LDP interfaces on which forwarding can be
disabled.";
uses ldp:ldp-interface-ref;
list address-family {
key "afi";
description
"Per-vrf per-af params.";
leaf afi {
type identityref {
base rt:address-family;
}
description
"Address family type value.";
}
leaf ldp-disable {
type boolean;
default "false";
description
"'true' to disable LDP forwarding on the interface.";
}
}
} // interface
} // interfaces
} // forwarding-nexthop
} // global-forwarding-nexthop-augment
grouping graceful-restart-augment {
description
"Augmentation to graceful restart.";
leaf helper-enabled {
if-feature "graceful-restart-helper-mode";
type boolean;
default "false";
description
"Enable or disable graceful restart helper mode.";
}
}
grouping interface-address-family-ipv4-augment {
description
"Augmentation to interface address family IPv4.";
leaf transport-address {
type union {
type enumeration {
enum use-global-transport-address {
description
"Use the transport address set at the global level
common for all interfaces for this address family.";
}
enum use-interface-address {
description
"Use interface address as the transport address.";
}
}
type inet:ipv4-address;
}
default "use-global-transport-address";
description
"IP address to be advertised as the LDP transport address.";
}
}
grouping interface-address-family-ipv6-augment {
description
"Augmentation to interface address family IPv6.";
leaf transport-address {
type union {
type enumeration {
enum use-global-transport-address {
description
"Use the transport address set at the global level
common for all interfaces for this address family.";
}
enum use-interface-address {
description
"Use interface address as the transport address.";
}
}
type inet:ipv6-address;
}
default "use-global-transport-address";
description
"IP address to be advertised as the LDP transport address.";
}
}Okay bestie, the YANG keeps going and it's giving very organized vibes 🎀✨
grouping interface-augment {
description
"Augmentation to interface.";
uses ldp:basic-discovery-timers {
if-feature "per-interface-timer-config";
}
leaf igp-synchronization-delay {
if-feature "per-interface-timer-config";
type uint16 {
range "0 | 3..300";
}
units "seconds";
description
"Sets the interval that the LDP waits before notifying the
Interior Gateway Protocol (IGP) that label exchange is
completed so that IGP can start advertising the normal
metric for the link.
This leaf may be configured at the per-interface level or
the global level, with precedence given to the value at the
per-interface level. If the leaf is not configured at
either level, the default value at the global level is
used.";
}
}
grouping peer-af-policy-container {
description
"LDP policy attribute container under peer address family.";
container label-policy {
description
"Label policy attributes.";
container advertise {
description
"Label advertising policies.";
leaf prefix-list {
type prefix-list-ref;
description
"Applies the prefix list to filter outgoing label
advertisements.
If the value is not specified, no prefix filter
is applied.";
}
}
container accept {
description
"Label advertisement acceptance policies.";
leaf prefix-list {
type prefix-list-ref;
description
"Applies the prefix list to filer incoming label
advertisements.
If the value is not specified, no prefix filter
is applied.";
}
}
}
} // peer-af-policy-container
grouping peer-augment {
description
"Augmentation to each peer list entry.";
leaf admin-down {
if-feature "per-peer-admin-down";
type boolean;
default "false";
description
"'true' to disable the peer.";
}
uses ldp:graceful-restart-attributes-per-peer {
if-feature "per-peer-graceful-restart-config";
}
uses ldp:peer-attributes {
if-feature "per-peer-session-attributes-config";
}
}
grouping peers-augment {
description
"Augmentation to peers container.";
container session-downstream-on-demand {
if-feature "session-downstream-on-demand-config";
description
"Session downstream-on-demand attributes.";
leaf enabled {
type boolean;
default "false";
description
"'true' if session downstream on demand is enabled.";
}
leaf peer-list {
type peer-list-ref;
description
"The name of a peer ACL, to be applied to the
downstream-on-demand sessions.
If this value is not specified, no filter is applied to
any downstream-on-demand sessions.";
}
}
container dual-stack-transport-preference {
if-feature "peers-dual-stack-transport-preference";
description
"The settings of peers to establish TCP connection in a
dual-stack setup.";
leaf max-wait {
type uint16 {
range "0..60";
}
default "30";
description
"The maximum wait time in seconds for preferred transport
connection establishment. 0 indicates no preference.";
}
container prefer-ipv4 {
presence "Present if IPv4 is preferred for transport
connection establishment, subject to the
'peer-list' in this container.";
description
"Uses IPv4 as the preferred address family for transport
connection establishment, subject to the 'peer-list' in
this container.
If this container is not present, as a default, IPv6 is
the preferred address family for transport connection
establishment.";
leaf peer-list {
type peer-list-ref;
description
"The name of a peer ACL, to be applied to the IPv4
transport connections.
If this value is not specified, no filter is applied,
and the IPv4 is preferred for all peers.";
}
}
}
} // peers-augment
grouping policy-container {
description
"LDP policy attributes.";
container label-policy {
description
"Label policy attributes.";
container advertise {
description
"Label advertising policies.";
container egress-explicit-null {
description
"Enables an egress router to advertise an
explicit null label (value 0) in place of an
implicit null label (value 3) to the
penultimate hop router.";
leaf enabled {
type boolean;
default "false";
description
"'true' to enable explicit null.";
}
}
leaf prefix-list {
type prefix-list-ref;
description
"Applies the prefix list to filter outgoing label
advertisements.
If the value is not specified, no prefix filter
is applied.";
}
}
container accept {
description
"Label advertisement acceptance policies.";
leaf prefix-list {
type prefix-list-ref;
description
"Applies the prefix list to filter incoming label
advertisements.
If the value is not specified, no prefix filter
is applied.";
}
}
container assign {
if-feature "policy-label-assignment-config";
description
"Label assignment policies.";
container independent-mode {
description
"Independent label policy attributes.";
leaf prefix-list {
type prefix-list-ref;
description
"Assign labels according to certain prefixes.
If the value is not specified, no prefix filter
is applied (labels are assigned to all learned
routes).";
}
}
container ordered-mode {
if-feature "policy-ordered-label-config";
description
"Ordered label policy attributes.";
leaf egress-prefix-list {
type prefix-list-ref;
description
"Assign labels according to certain prefixes for
egress LSR.";
}
}
} // assign
} // label-policy
} // policy-container
/*
* Configuration and state data nodes
*/
// Forwarding nexthop augmentation to the global tree
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ldp:mpls-ldp/ldp:global" {
description
"Forwarding nexthop augmentation.";
uses global-forwarding-nexthop-augment;
}
// global/address-families/ipv6
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ldp:mpls-ldp/ldp:global/"
+ "ldp:address-families" {
description
"Global IPv6 augmentation.";
container ipv6 {
presence "Present if IPv6 is enabled, unless the 'enabled'
leaf is set to 'false'.";
description
"Containing data related to the IPv6 address family.";
leaf enabled {
type boolean;
default "true";
description
"'false' to disable the address family.";
}
uses policy-container;
leaf transport-address {
type inet:ipv6-address;
mandatory true;
description
"The transport address advertised in LDP Hello messages.";
}
leaf label-distribution-control-mode {
type enumeration {
enum independent {
description
"Independent label distribution control.";
}
enum ordered {
description
"Ordered label distribution control.";
}
}
config false;
description
"Label distribution control mode.";
reference
"RFC 5036: LDP Specification, Sec. 2.6.";
}
// ipv6 bindings
container bindings {
config false;
description
"LDP address and label binding information.";
list address {
key "address";
description
"List of address bindings learned by LDP.";
leaf address {
type inet:ipv6-address;
description
"The IPv6 address learned from an Address
message received from or advertised to a peer.";
}
uses ldp:binding-address-state-attributes;
}
list fec-label {
key "fec";
description
"List of FEC-label bindings learned by LDP.";
leaf fec {
type inet:ipv6-prefix;
description
"The prefix FEC value in the FEC-Label binding,
learned in a Label Mapping message received from
or advertised to a peer.";
}
uses ldp:binding-label-state-attributes;
}
} // bindings
} // ipv6
}
// discovery/interfaces/interface/address-families/ipv6
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ldp:mpls-ldp/ldp:discovery/"
+ "ldp:interfaces/ldp:interface/"
+ "ldp:address-families" {
description
"Interface IPv6 augmentation.";
container ipv6 {
presence "Present if IPv6 is enabled, unless the 'enabled'
leaf is set to 'false'.";
description
"IPv6 address family.";
leaf enabled {
type boolean;
default "true";
description
"'false' to disable the address family on the interface.";
}
container hello-adjacencies {
config false;
description
"Containing a list of Hello adjacencies.";
list hello-adjacency {
key "adjacent-address";
config false;
description
"List of Hello adjacencies.";
leaf adjacent-address {
type inet:ipv6-address;
description
"Neighbor address of the Hello adjacency.";
}
uses ldp:adjacency-state-attributes;
uses ldp:ldp-peer-ref-from-interface;
}
}
} // ipv6
}
// discovery/targeted/address-families/ipv6 augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ldp:mpls-ldp/ldp:discovery/"
+ "ldp:targeted/ldp:address-families" {
description
"Targeted discovery IPv6 augmentation.";
container ipv6 {
presence "Present if IPv6 is enabled.";
description
"IPv6 address family.";
container hello-adjacencies {
config false;
description
"Containing a list of Hello adjacencies.";
list hello-adjacency {
key "local-address adjacent-address";
config false;
description
"List of Hello adjacencies.";
leaf local-address {
type inet:ipv6-address;
description
"Local address of the Hello adjacency.";
}
leaf adjacent-address {
type inet:ipv6-address;
description
"Neighbor address of the Hello adjacency.";
}
uses ldp:adjacency-state-attributes;
uses ldp:ldp-peer-ref-from-target;
}
}
list target {
key "adjacent-address";
description
"Targeted discovery params.";
leaf adjacent-address {
type inet:ipv6-address;
description
"Configures a remote LDP neighbor for the
extended LDP discovery.";
}
leaf enabled {
type boolean;
default "true";
description
"'true' to enable the target.";
}
leaf local-address {
type inet:ipv6-address;
description
"The local address used as the source address to send
targeted Hello messages.
If the value is not specified, the transport address
is used as the source address.";
}
} // target
} // ipv6
}
// /peers/peer/state/address-families/ipv6
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ldp:mpls-ldp/ldp:peers/"
+ "ldp:peer/ldp:address-families" {
description
"Peer state IPv6 augmentation.";
container ipv6 {
presence "Present if IPv6 is enabled.";
description
"IPv6 address family.";
container hello-adjacencies {
config false;
description
"Containing a list of Hello adjacencies.";
list hello-adjacency {
key "local-address adjacent-address";
description
"List of Hello adjacencies.";
leaf local-address {
type inet:ipv6-address;
description
"Local address of the Hello adjacency.";
}
leaf adjacent-address {
type inet:ipv6-address;
description
"Neighbor address of the Hello adjacency.";
}
uses ldp:adjacency-state-attributes;
leaf interface {
type if:interface-ref;
description
"Interface for this adjacency.";
}
}
}
} // ipv6
}
/*
* Configuration data and operational state data nodes
*/
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ldp:mpls-ldp/ldp:global" {
description
"Graceful restart augmentation.";
uses global-augment;
}
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ldp:mpls-ldp/ldp:global/"
+ "ldp:capability" {
description
"Capability augmentation.";
uses capability-augment;
}
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ldp:mpls-ldp/ldp:global/"
+ "ldp:graceful-restart" {
description
"Graceful restart augmentation.";
uses graceful-restart-augment;
}
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ldp:mpls-ldp/ldp:global/"
+ "ldp:address-families/ldp:ipv4" {
description
"Address family IPv4 augmentation.";
uses address-family-ipv4-augment;
}
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ldp:mpls-ldp/ldp:discovery/"
+ "ldp:interfaces/ldp:interface" {
description
"Interface augmentation.";
uses interface-augment;
}
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ldp:mpls-ldp/ldp:discovery/"
+ "ldp:interfaces/ldp:interface/ldp:address-families/"
+ "ldp:ipv4" {
description
"Interface address family IPv4 augmentation.";
uses interface-address-family-ipv4-augment;
}
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ldp:mpls-ldp/ldp:discovery/"
+ "ldp:interfaces/ldp:interface/ldp:address-families/"
+ "ldp-ext:ipv6" {
description
"Interface address family IPv6 augmentation.";
uses interface-address-family-ipv6-augment;
}
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ldp:mpls-ldp/ldp:discovery/"
+ "ldp:targeted/ldp:hello-accept" {
description
"Targeted discovery augmentation.";
leaf neighbor-list {
if-feature "policy-targeted-discovery-config";
type neighbor-list-ref;
description
"The name of a neighbor ACL, used to accept Hello messages
from LDP peers as permitted by the neighbor-list policy.
If this value is not specified, targeted Hello messages
from any source are accepted.";
}
}
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ldp:mpls-ldp/ldp:peers" {
description
"Peers augmentation.";
uses peers-augment;
}
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ldp:mpls-ldp/ldp:peers/"
+ "ldp:authentication/ldp:authentication-type" {
if-feature "key-chain";
description
"Peers authentication augmentation.";
case key-chain {
uses authentication-keychain-augment;
}
}
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ldp:mpls-ldp/ldp:peers/"
+ "ldp:peer" {
description
"Peer list entry augmentation.";
uses peer-augment;
}
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ldp:mpls-ldp/ldp:peers/"
+ "ldp:peer/ldp:authentication/ldp:authentication-type" {
if-feature "key-chain";
description
"Peer list entry authentication augmentation.";
case key-chain {
uses authentication-keychain-augment;
}
}
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ldp:mpls-ldp/ldp:peers/"
+ "ldp:peer/ldp:address-families/ldp:ipv4" {
description
"Peer list entry IPv4 augmentation.";
uses peer-af-policy-container;
}
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ldp:mpls-ldp/ldp:peers/"
+ "ldp:peer/ldp:address-families/ldp-ext:ipv6" {
description
"Peer list entry IPv6 augmentation.";
uses peer-af-policy-container;
}
}
<CODE ENDS>
Figure 11: LDP Extended Module10. Security Considerations 🔐✨
Okay bestie, security time, and this part is SERIOUS (no cap) 😭. This specification inherits the security considerations captured in [RFC5920] and the LDP protocol specification documents, namely base LDP [RFC5036], LDP IPv6 [RFC7552], LDP Capabilities [RFC5561], Typed Wildcard FEC [RFC5918], LDP End-of-LIB [RFC5919], and LDP Upstream Label Assignment [RFC6389]. So if you're reading this, those are the homework too 📚💅.
10.1. YANG Data Model
The YANG modules in this document define a schema for data that's meant to be reached through network management protocols like NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer is the secure transport layer, and the mandatory-to-implement secure transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer is HTTPS, and the mandatory-to-implement secure transport is TLS [RFC8446].
The Network Configuration Access Control Model (NACM) [RFC8341] gives you the means to restrict access for particular NETCONF or RESTCONF users to a preconfigured subset of all the available protocol operations and content. Bouncer energy 🚪🫶
10.1.1. Writable Nodes
There are a bunch of data nodes in these YANG modules that are writable/creatable/deletable (aka config true, which is the default). These data nodes may be considered sensitive or vulnerable in some network environments, and write operations (e.g., edit-config) to them without proper protection can have a negative effect on network operations. 😬
For LDP, the ability to modify MPLS LDP configuration may allow the entire MPLS LDP domain to be compromised, including forming LDP adjacencies and/or peer sessions with unauthorized routers to mount a massive Denial-of-Service (DoS) attack. 💀 These are the subtrees and data nodes that are sensitive and vulnerable:
/mpls-ldp/discovery/interfaces/interface: adding LDP on any unprotected interface could allow an LDP Hello adjacency to be formed with an unauthorized and malicious neighbor. Once a Hello adjacency is formed, a peer session could progress with this neighbor./mpls-ldp/discovery/targeted/hello-accept: allowing acceptance of targeted-hellos could open LDP to DoS attacks related to incoming targeted hellos from malicious sources./mpls-ldp/peers/authentication: allowing a peer session establishment is typically controlled via LDP authentication, where a proper and secure authentication password/key management is warranted./mpls-ldp/peers/peer/authentication: same as above.
Main character warning 🚨: a misconfigured hello-accept or peer authentication node is basically an open door for a malicious router to walk right into your MPLS LDP domain. Lock these down, periodt 🔥.
10.1.2. Readable Nodes 👀
Okay so some of the readable data nodes in these YANG modules may be considered sensitive or vulnerable in some network environments 😬 It is super important to control read access (think get, get-config, or notification) to these data nodes 🔒 Here's the list of subtrees and data nodes and why they're sensitive or vulnerable 💅
Spilling LDP databases (like Hello adjacencies, peers, address bindings, and FEC-Label bindings) outside the LDP admin domain may be undesirable 🙈 The relevant subtrees and data nodes are:
/mpls-ldp/global/address-families/ipv4/bindings/address/mpls-ldp/global/address-families/ipv6/bindings/address/mpls-ldp/global/address-families/ipv4/bindings/fec-label/mpls-ldp/global/address-families/ipv6/bindings/fec-label/mpls-ldp/discovery/interfaces/interface/address-families/ipv4/hello-adjacencies/mpls-ldp/discovery/interfaces/interface/address-families/ipv6/hello-adjacencies/mpls-ldp/discovery/targeted/address-families/ipv4/hello-adjacencies/mpls-ldp/discovery/targeted/address-families/ipv6/hello-adjacencies/mpls-ldp/peers
LDP peer authentication is supported via the key-chain specification [RFC8177] or via direct specification of a key tied to a crypto algorithm (like MD5) 🔑 The relevant subtrees and data nodes are:
/mpls-ldp/peers/authentication/mpls-ldp/peers/peer/authentication
The actual key data (whether it's set locally or lives in a key-chain) is sensitive and has to stay secret from unauthorized folks 🤫 For key-chain-based authentication, this model inherits the security considerations of [RFC8040] (which covers how authentication keys get stored and handled locally). A similar procedure for storing and accessing direct keys is warranted.
10.1.3. RPC Operations 🚨
Some RPC operations in these YANG modules may be considered sensitive or vulnerable in some network environments 😳 So it's important to control access to them, otherwise control plane flaps, network outages, and DoS attacks are possible. The RPC operations are:
mpls-ldp-clear-peermpls-ldp-clear-hello-adjacency
10.1.4. Notifications 🔔
The model describes several notifications. Implementations must rate-limit how these get generated, so they don't create a heavy notification load or possible side effects on system stability 🫶
11. IANA Considerations ✨
Per this document, the following URIs have been registered in the IETF "XML Registry" [RFC3688]:
URI: urn:ietf:params:xml:ns:yang:ietf-mpls-ldp
Registrant: The IESG
XML: N/A
URI: urn:ietf:params:xml:ns:yang:ietf-mpls-ldp-extended
Registrant: The IESG
XML: N/APer this document, the following YANG modules have been registered in the "YANG Module Names" registry [RFC6020]:
Name: ietf-mpls-ldp
Namespace: urn:ietf:params:xml:ns:yang:ietf-mpls-ldp
Prefix: ldp
Reference: RFC 9070
Name: ietf-mpls-ldp-extended
Namespace: urn:ietf:params:xml:ns:yang:ietf-mpls-ldp-extended
Prefix: ldp-ext
Reference: RFC 907012. Normative References 📚
- [RFC3478] Leelanivas, M., Rekhter, Y., and R. Aggarwal, "Graceful Restart Mechanism for Label Distribution Protocol", RFC 3478, DOI 10.17487/RFC3478, February 2003,
https://www.rfc-editor.org/info/rfc3478 - [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004,
https://www.rfc-editor.org/info/rfc3688 - [RFC5036] Andersson, L., Ed., Minei, I., Ed., and B. Thomas, Ed., "LDP Specification", RFC 5036, DOI 10.17487/RFC5036, October 2007,
https://www.rfc-editor.org/info/rfc5036 - [RFC5331] Aggarwal, R., Rekhter, Y., and E. Rosen, "MPLS Upstream Label Assignment and Context-Specific Label Space", RFC 5331, DOI 10.17487/RFC5331, August 2008,
https://www.rfc-editor.org/info/rfc5331 - [RFC5443] Jork, M., Atlas, A., and L. Fang, "LDP IGP Synchronization", RFC 5443, DOI 10.17487/RFC5443, March 2009,
https://www.rfc-editor.org/info/rfc5443 - [RFC5561] Thomas, B., Raza, K., Aggarwal, S., Aggarwal, R., and JL. Le Roux, "LDP Capabilities", RFC 5561, DOI 10.17487/RFC5561, July 2009,
https://www.rfc-editor.org/info/rfc5561 - [RFC5918] Asati, R., Minei, I., and B. Thomas, "Label Distribution Protocol (LDP) 'Typed Wildcard' Forward Equivalence Class (FEC)", RFC 5918, DOI 10.17487/RFC5918, August 2010,
https://www.rfc-editor.org/info/rfc5918 - [RFC5919] Asati, R., Mohapatra, P., Chen, E., and B. Thomas, "Signaling LDP Label Advertisement Completion", RFC 5919, DOI 10.17487/RFC5919, August 2010,
https://www.rfc-editor.org/info/rfc5919 - [RFC5920] Fang, L., Ed., "Security Framework for MPLS and GMPLS Networks", RFC 5920, DOI 10.17487/RFC5920, July 2010,
https://www.rfc-editor.org/info/rfc5920 - [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 - [RFC6389] Aggarwal, R. and JL. Le Roux, "MPLS Upstream Label Assignment for LDP", RFC 6389, DOI 10.17487/RFC6389, November 2011,
https://www.rfc-editor.org/info/rfc6389 - [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013,
https://www.rfc-editor.org/info/rfc6991 - [RFC7552] Asati, R., Pignataro, C., Raza, K., Manral, V., and R. Papneja, "Updates to LDP for IPv6", RFC 7552, DOI 10.17487/RFC7552, June 2015,
https://www.rfc-editor.org/info/rfc7552 - [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 - [RFC8177] Lindem, A., Ed., Qu, Y., Yeung, D., Chen, I., and J. Zhang, "YANG Data Model for Key Chains", RFC 8177, DOI 10.17487/RFC8177, June 2017,
https://www.rfc-editor.org/info/rfc8177 - [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 - [RFC8343] Bjorklund, M., "A YANG Data Model for Interface Management", RFC 8343, DOI 10.17487/RFC8343, March 2018,
https://www.rfc-editor.org/info/rfc8343 - [RFC8344] Bjorklund, M., "A YANG Data Model for IP Management", RFC 8344, DOI 10.17487/RFC8344, March 2018,
https://www.rfc-editor.org/info/rfc8344 - [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 - [RFC8407] Bierman, A., "Guidelines for Authors and Reviewers of Documents Containing YANG Data Models", BCP 216, RFC 8407, DOI 10.17487/RFC8407, October 2018,
https://www.rfc-editor.org/info/rfc8407 - [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 - [RFC8529] Berger, L., Hopps, C., Lindem, A., Bogdanovic, D., and X. Liu, "YANG Data Model for Network Instances", RFC 8529, DOI 10.17487/RFC8529, March 2019,
https://www.rfc-editor.org/info/rfc8529 - [RFC9067] Qu, Y., Tantsura, J., Lindem, A., and X. Liu, "A YANG Data Model for Routing Policy", RFC 9067, DOI 10.17487/RFC9067, October 2021,
https://www.rfc-editor.org/info/rfc9067
13. Informative References 🌸
- [MPLS-MLDP-YANG] Raza, K., Ed., Liu, X., Esale, S., Andersson, L., Tantsura, J., and S. Krishnaswamy, "YANG Data Model for MPLS mLDP", Work in Progress, Internet-Draft, draft-ietf-mpls-mldp-yang-10, 11 November 2021,
https://datatracker.ietf.org/doc/html/draft-ietf-mpls-mldp-yang-10 - [RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February 2006,
https://www.rfc-editor.org/info/rfc4364 - [RFC7307] Zhao, Q., Raza, K., Zhou, C., Fang, L., Li, L., and D. King, "LDP Extensions for Multi-Topology", RFC 7307, DOI 10.17487/RFC7307, July 2014,
https://www.rfc-editor.org/info/rfc7307 - [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
Appendix A. Data Tree Example ✨
okay so bestie, this section is a full worked example 🦋 of an instance data tree in the JSON encoding [RFC7951], and it has both configuration AND state data in it. it's literally the best way to see how everything fits together 💖
Here's the topology we're working with. Router 203.0.113.1 sits on eth1 with 2001:db8:0:1::1/64, and another router on the same link uses 2001:db8:0:1::2/64. That other router also has 2001:db8:0:2::/64 behind it. ASCII art is so cute 🎀
+---------------------+
| |
| Router 203.0.113.1 |
| |
+----------+----------+
|eth1
|2001:db8:0:1::1/64
|
|
|2001:db8:0:1::2/64
+----------+----------+
| | |
| Another Router +---------| 2001:db8:0:2::/64
| | |
+---------------------+Figure 12: Example Topology
okay so the configuration instance data tree for Router 203.0.113.1 in Figure 12 could look like this 💅
{
"ietf-interfaces:interfaces": {
"interface": [
{
"name": "eth1",
"description": "An interface with LDP enabled.",
"type": "iana-if-type:ethernetCsmacd",
"ietf-ip:ipv6": {
"address": [
{
"ip": "2001:db8:0:1::1",
"prefix-length": 64
}
],
"forwarding": true
}
}
]
},
"ietf-routing:routing": {
"router-id": "203.0.113.1",
"control-plane-protocols": {
"control-plane-protocol": [
{
"type": "ietf-mpls-ldp:mpls-ldp",
"name": "ldp-1",
"ietf-mpls-ldp:mpls-ldp": {
"global": {
"address-families": {
"ietf-mpls-ldp-extended:ipv6": {
"enabled": true,
"transport-address": "2001:db8:0:1::1"
}
}
},
"discovery": {
"interfaces": {
"interface": [
{
"name": "eth1",
"address-families": {
"ietf-mpls-ldp-extended:ipv6": {
"enabled": true
}
}
}
]
}
}
}
}
]
}
}
}Figure 13: Example Configuration Data in JSON
And the matching operational state data for Router 203.0.113.1 could look like this 🌸 It's the same config PLUS all the live stuff: MAC addresses, oper-status, neighbors, hello adjacencies, peers, and timers. Main character energy 👑
{
"ietf-interfaces:interfaces": {
"interface": [
{
"name": "eth1",
"description": "An interface with LDP enabled.",
"type": "iana-if-type:ethernetCsmacd",
"phys-address": "00:00:5e:00:53:01",
"oper-status": "up",
"statistics": {
"discontinuity-time": "2018-09-10T15:16:27-05:00"
},
"ietf-ip:ipv6": {
"forwarding": true,
"mtu": 1500,
"address": [
{
"ip": "2001:db8:0:1::1",
"prefix-length": 64,
"origin": "static",
"status": "preferred"
},
{
"ip": "fe80::200:5eff:fe00:5301",
"prefix-length": 64,
"origin": "link-layer",
"status": "preferred"
}
],
"neighbor": [
{
"ip": "2001:db8:0:1::2",
"link-layer-address": "00:00:5e:00:53:02",
"origin": "dynamic",
"is-router": [null],
"state": "reachable"
},
{
"ip": "fe80::200:5eff:fe00:5302",
"link-layer-address": "00:00:5e:00:53:02",
"origin": "dynamic",
"is-router": [null],
"state": "reachable"
}
]
}
}
]
},
"ietf-routing:routing": {
"router-id": "203.0.113.1",
"interfaces": {
"interface": [
"eth1"
]
},
"control-plane-protocols": {
"control-plane-protocol": [
{
"type": "ietf-mpls-ldp:mpls-ldp",
"name": "ldp-1",
"ietf-mpls-ldp:mpls-ldp": {
"global": {
"address-families": {
"ietf-mpls-ldp-extended:ipv6": {
"enabled": true,
"transport-address": "2001:db8:0:1::1"
}
}
},
"discovery": {
"interfaces": {
"interface": [
{
"name": "eth1",
"address-families": {
"ietf-mpls-ldp-extended:ipv6": {
"enabled": true,
"hello-adjacencies": {
"hello-adjacency": [
{
"adjacent-address":
"fe80::200:5eff:fe00:5302",
"flag": ["adjacency-flag-active"],
"hello-holdtime": {
"adjacent": 15,
"negotiated": 15,
"remaining": 9
},
"next-hello": 3,
"statistics": {
"discontinuity-time":
"2018-09-10T15:16:27-05:00"
},
"peer": {
"lsr-id": "203.0.113.2",
"label-space-id": 0
}
}
]
}
}
}
}
]
}
},
"peers": {
"peer": [
{
"lsr-id": "203.0.113.2",
"label-space-id": 0,
"label-advertisement-mode": {
"local": "downstream-unsolicited",
"peer": "downstream-unsolicited",
"negotiated": "downstream-unsolicited"
},
"next-keep-alive": 5,
"session-holdtime": {
"peer": 180,
"negotiated": 180,
"remaining": 78
},
"session-state": "operational",
"tcp-connection": {
"local-address": "fe80::200:5eff:fe00:5301",
"local-port": 646,
"remote-address": "fe80::200:5eff:fe00:5302",
"remote-port": 646
},
"up-time": 3438100,
"statistics": {
"discontinuity-time": "2018-09-10T15:16:27-05:00"
}
}
]
}
}
}
]
}
}
}Figure 14: Example Operational Data in JSON
Acknowledgments 🫶
the authors wanna give a huge shoutout to Eddie Chami, Nagendra Kumar, Mannan Venkatesan, and Pavan Beeram for their contribution to this document 💜
we also send love to Ladislav Lhotka, Jan Lindblad, Tom Petch, Yingzhen Qu, and Benjamin Kaduk for their detailed review of the model during WG and IESG processes 🌈 they really went through it with a fine-tooth comb, iconic behavior ✨
Contributors 💅
Danial Johari Cisco Systems Email: dajohari@cisco.com
Loa Andersson Huawei Technologies Email: loa@pi.nu
Jeff Tantsura Apstra Email: jefftant.ietf@gmail.com
Matthew Bocci Nokia Email: matthew.bocci@nokia.com
Reshad Rahman Email: reshad@yahoo.com
Stephane Litkowski Cisco Systems Email: slitkows@cisco.com
Authors' Addresses 🦋
Kamran Raza (editor) Cisco Systems Canada Email: skraza@cisco.com
Rajiv Asati Cisco Systems United States of America Email: rajiva@cisco.com
Xufeng Liu IBM Corporation United States of America Email: xufeng.liu.ietf@gmail.com
Santosh Easale Juniper Networks United States of America Email: santosh_easale@berkeley.edu
Xia Chen Huawei Technologies China Email: jescia.chenxia@huawei.com
Himanshu Shah Ciena Corporation United States of America Email: hshah@ciena.com
📦 where this page comes from
- ietf: rfc9070 2022-03
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