]> Telefonica

oscar.gonzalezdedios@telefonica.com

Telefonica

samier.barguilgiraldo.ext@telefonica.com

Nokia

victor.lopez@nokia.com

Routing lsr This document defines a YANG data model for representing an abstract view of the provider network topology that contains Intermediate System to intermediate System (ISIS) information. This document augments the 'ietf-network' data model by adding ISIS concepts. The YANG data model defined in this document conforms to the Network Management Datastore Architecture (NMDA). Discussion Venues Discussion of this document takes place on the Link State Routing Working Group mailing list (lsr@ietf.org), which is archived at . Source for this draft and an issue tracker can be found at .

Introduction This document defines a YANG data model for representing an abstract view of the provider network topology that contains Intermediate System to intermediate System (ISIS) information. The data model augments ietf-network module by adding ISIS information. Network operators perform regular what-if sceanarios analysis and capacity planning processes. Those what-if analysis and capacity planning processes require, among other information, a topological view (nodes, links, network interconnection) of the deployed network. Thanks to the definition of the ietf-network model in network operators can use an API to dynamically get the topological information from a network controller/ network management system. On top of the work in , and extend the generic network and network topology data models with topology attributes that are specific to Layer 3 and Layer 2. However, there is not any model that exposes the IGP details. This information is required in the IP/MPLS planning process to properly assess the required network resources to meet the traffic demands in normal and failure scenarios. A whatif analysis requires knowledge on the different levels and areas. The main objective of this model is to represent the most relevant ISIS topology attributes.This document defines a YANG data model for representing, managing and controlling the ISIS topology. The data model augments ietf-network module by adding the ISIS information. This document explains the scope and purpose of the ISIS topology model and how the topology and service models fit together. The YANG data model defined in this document conforms to the Network Management Datastore Architecture .

Terminology and Notations This document assumes that the reader is familiar with the contents of . The document uses terms from those documents. The terminology for describing YANG data models is found in , and .

Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in , when, and only when, they appear in all capitals, as shown here.

Tree Diagram Authors include a simplified graphical representation of the data model is used in of this document. The meaning of the symbols in these diagrams is defined in .

Prefix in Data Node Names In this document, names of data nodes and other data model objects are prefixed using the standard prefix associated with the corresponding YANG imported modules, as shown in the following table. Prefixes and corresponding YANG modules

Prefix	Yang Module	Reference
isisnt	ietf-l3-isis-topology	RFCXXX
yang	ietf-yang-types

RFC Editor Note: Please replace XXXX with the RFC number assigned to this document. Please remove this note.

YANG Data Model for ISIS Topology The abstract (base) network data model is defined in the "ietf-network" module of . The ISIS-topology builds on the network data model defined in the "ietf-network" module , augmenting the nodes with ISIS information, which anchor the links and are contained in nodes). There is a set of parameters and augmentations that are included at the node level. Each parameter and description are detailed following:

• Network-types: Its presence identifies the ISIS topology type. Thus, the network type MUST be isis-topology.
• ISIS timer attributes: Identifies the node timer attributes configured in the network element. They are LSP lifetime and the LSP refresh interval.
• ISIS status: contains the ISIS status attributes (level, area-address and neighbours).

There is a second set of parameters and augmentations are included at the termination point level. Each parameter is listed as follows:

• Interface-type
• Level
• Metric
• Passive mode

ISIS Topology Tree Diagram below shows the tree diagram of the YANG data model defined in module ietf-l3-isis-topology.yang ().

ISIS Topology tree diagram

YANG Model for ISIS topology This module imports types from and . Following the YANG model is presented.

ISIS Topology YANG module WG List: Editor: Oscar Gonzalez de Dios Editor: Samier Barguil Editor: Victor Lopez "; description "This module defines a model for Layer 3 ISIS topologies. 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 XXXX (https://www.rfc-editor.org/info/rfcXXXX); see the RFC itself for full legal notices."; revision 2022-09-21 { description "Initial version"; reference "RFC XXXX: A YANG Data Model for Intermediate System to Intermediate System (ISIS) Topology"; } grouping isis-topology-type { description "Identifies the topology type to be ISIS."; container isis-topology { presence "indicates ISIS topology"; description "The presence of the container node indicates ISIS topology"; } } grouping isis-node-attributes { description "isis node scope attributes"; container isis-timer-attributes { description "Contains node timer attributes"; leaf lsp-lifetime { type uint16 { range "1..65535"; } units "seconds"; description "Lifetime of the router's LSPs in seconds."; } leaf lsp-refresh-interval { type uint16 { range "1..65535"; } units "seconds"; description "Refresh interval of the router's LSPs in seconds."; } } container isis-status { description "Contains the ISIS status attributes"; leaf level { type ietf-isis:level; description "Level of an IS-IS node - can be level-1, level-2 or level-all."; } leaf-list area-address { type ietf-isis:area-address; description "List of areas supported by the protocol instance."; } leaf system-id { type ietf-isis:system-id; description "System-id of the node."; } leaf-list neighbors { type inet:ip-address; config false; description "Topology flags"; } } } grouping isis-termination-point-attributes { description "ISIS termination point scope attributes"; container isis-termination-point-attributes { description "Indicates the termination point from the which the ISIS is configured. A termination point can be a physical port, an interface, etc."; leaf interface-type { type ietf-isis:interface-type; description "Type of adjacency to be established for the interface. This dictates the type of hello messages that are used."; } leaf level { type ietf-isis:level; description "Level of an IS-IS node - can be level-1, level-2 or level-all."; } leaf metric { type uint32 { range "0 .. 16777215"; } description "This type defines wide style format of IS-IS metric."; } leaf is-passive{ type boolean; description "Indicates whether the interface is in passive mode (IS-IS not running but network is advertised)."; } } } augment "/nw:networks/nw:network/nw:network-types" { description "Introduces new network type for L3 Unicast topology"; uses isis-topology-type; } augment "/nw:networks/nw:network/nw:node/l3t:l3-node-attributes" { when "/nw:networks/nw:network/nw:network-types/isisnt:isis-topology" { description "Augmentation parameters apply only for networks with isis topology"; } description "isis node-level attributes "; uses isis-node-attributes; } augment "/nw:networks/nw:network/nt:link/l3t:l3-link-attributes" { when "/nw:networks/nw:network/nw:network-types/isisnt:isis-topology" { description "Augmentation parameters apply only for networks with ISIS topology"; } description "Augments topology link configuration"; uses isis-termination-point-attributes; } augment "/nw:networks/nw:network/nw:node/nt:termination-point"+ "/l3t:l3-termination-point-attributes" { when "/nw:networks/nw:network/nw:network-types/isisnt:isis-topology" { description "Augmentation parameters apply only for networks with ISIS topology"; } description "Augments topology termination point configuration"; uses isis-termination-point-attributes; } } ]]>

Security Considerations The YANG module specified in this document defines a schema for data that is designed to be accessed via network management protocols such as NETCONF or RESTCONF . The lowest NETCONF layer is the secure transport layer, and the mandatory-to-implement secure transport is Secure Shell (SSH) . The lowest RESTCONF layer is HTTPS, and the mandatory-to-implement secure transport is TLS . The NETCONF access control model provides the means to restrict access for particular NETCONF or RESTCONF users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content. There are a number of data nodes defined in this YANG module that are writable/creatable/deletable (i.e., config true, which is the default). These data nodes may be considered sensitive or vulnerable in some network environments. Write operations (e.g., edit-config) to these data nodes without proper protection can have a negative effect on network operations.

IANA Considerations This document registers the following namespace URIs in the IETF XML registry : This document registers the following YANG module in the YANG Module Names registry :

Implementation Status This section will be used to track the status of the implementations of the model. It is aimed at being removed if the document becomes RFC.

Normative References This document defines an abstract (generic, or base) YANG data model for network/service topologies and inventories. The data model serves as a base model that is augmented with technology-specific details in other, more specific topology and inventory data models. This document defines a YANG data model for Layer 3 network topologies. This document defines a YANG data model for Layer 2 network topologies. In particular, this data model augments the generic network and network topology data models with topology attributes that are specific to Layer 2. Datastores are a fundamental concept binding the data models written in the YANG data modeling language to network management protocols such as the Network Configuration Protocol (NETCONF) and RESTCONF. This document defines an architectural framework for datastores based on the experience gained with the initial simpler model, addressing requirements that were not well supported in the initial model. This document updates RFC 7950. YANG is a data modeling language used to model configuration data, state data, Remote Procedure Calls, and notifications for network management protocols. This document describes the syntax and semantics of version 1.1 of the YANG language. YANG version 1.1 is a maintenance release of the YANG language, addressing ambiguities and defects in the original specification. There are a small number of backward incompatibilities from YANG version 1. This document also specifies the YANG mappings to the Network Configuration Protocol (NETCONF). This document defines a YANG data model for representing, retrieving, and manipulating Traffic Engineering (TE) Topologies. The model serves as a base model that other technology-specific TE topology models can augment. In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. RFC 2119 specifies common key words that may be used in protocol specifications. This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings. This document captures the current syntax used in YANG module tree diagrams. The purpose of this document is to provide a single location for this definition. This syntax may be updated from time to time based on the evolution of the YANG language. This document introduces a collection of common data types to be used with the YANG data modeling language. This document obsoletes RFC 6021. This document defines a YANG data model for the management of network interfaces. It is expected that interface-type-specific data models augment the generic interfaces data model defined in this document. The data model includes definitions for configuration and system state (status information and counters for the collection of statistics). The YANG data model in this document conforms to the Network Management Datastore Architecture (NMDA) defined in RFC 8342. This document obsoletes RFC 7223. The Network Configuration Protocol (NETCONF) defined in this document provides mechanisms to install, manipulate, and delete the configuration of network devices. It uses an Extensible Markup Language (XML)-based data encoding for the configuration data as well as the protocol messages. The NETCONF protocol operations are realized as remote procedure calls (RPCs). This document obsoletes RFC 4741. [STANDARDS-TRACK] This document describes an HTTP-based protocol that provides a programmatic interface for accessing data defined in YANG, using the datastore concepts defined in the Network Configuration Protocol (NETCONF). This document describes a method for invoking and running the Network Configuration Protocol (NETCONF) within a Secure Shell (SSH) session as an SSH subsystem. This document obsoletes RFC 4742. [STANDARDS-TRACK] This document specifies Version 1.2 of the Transport Layer Security (TLS) protocol. The TLS protocol provides communications security over the Internet. The protocol allows client/server applications to communicate in a way that is designed to prevent eavesdropping, tampering, or message forgery. [STANDARDS-TRACK] The standardization of network configuration interfaces for use with the Network Configuration Protocol (NETCONF) requires a structured and secure operating environment that promotes human usability and multi-vendor interoperability. There is a need for standard mechanisms to restrict NETCONF protocol access for particular users to a pre-configured subset of all available NETCONF protocol operations and content. This document defines such an access control model. [STANDARDS-TRACK] This document describes an IANA maintained registry for IETF standards which use Extensible Markup Language (XML) related items such as Namespaces, Document Type Declarations (DTDs), Schemas, and Resource Description Framework (RDF) Schemas. YANG is a data modeling language used to model configuration and state data manipulated by the Network Configuration Protocol (NETCONF), NETCONF remote procedure calls, and NETCONF notifications. [STANDARDS-TRACK]

Acknowledgments This work is partially supported by the European Commission under Horizon 2020 Secured autonomic traffic management for a Tera of SDN flows (Teraflow) project (grant agreement number 101015857).