lsr O. G. D. Dios Internet-Draft S. Barguil Intended status: Standards Track Telefonica Expires: 27 April 2023 V. Lopez Nokia 24 October 2022 A YANG Data Model for Intermediate System to intermediate System (ISIS) Topology draft-ogondio-lsr-isis-topology-00 Abstract 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 This note is to be removed before publishing as an RFC. Discussion of this document takes place on the Link State Routing Working Group mailing list (lsr@ietf.org), which is archived at https://mailarchive.ietf.org/arch/browse/lsr/. Source for this draft and an issue tracker can be found at https://github.com/oscargdd/draft-ogondio-lsr-isis-topology. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." Dios, et al. Expires 27 April 2023 [Page 1] Internet-Draft ISIS Topology YANG October 2022 This Internet-Draft will expire on 27 April 2023. 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 . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Terminology and Notations . . . . . . . . . . . . . . . . 3 1.2. Requirements Language . . . . . . . . . . . . . . . . . . 3 1.3. Tree Diagram . . . . . . . . . . . . . . . . . . . . . . 3 1.4. Prefix in Data Node Names . . . . . . . . . . . . . . . . 3 2. YANG Data Model for ISIS Topology . . . . . . . . . . . . . . 4 3. ISIS Topology Tree Diagram . . . . . . . . . . . . . . . . . 5 4. YANG Model for ISIS topology . . . . . . . . . . . . . . . . 5 5. Security Considerations . . . . . . . . . . . . . . . . . . . 10 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 7. Implementation Status . . . . . . . . . . . . . . . . . . . . 11 8. Normative References . . . . . . . . . . . . . . . . . . . . 11 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 13 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13 1. 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 [RFC8345] 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 [RFC8345] 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 [RFC8345], [RFC8346] and [RFC8944] extend the Dios, et al. Expires 27 April 2023 [Page 2] Internet-Draft ISIS Topology YANG October 2022 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 [RFC8345] 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 [RFC8342]. 1.1. Terminology and Notations This document assumes that the reader is familiar with the contents of [RFC8345]. The document uses terms from those documents. The terminology for describing YANG data models is found in [RFC7950], [RFC8795] and [RFC8346]. 1.2. 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 [RFC2119], [RFC8174] when, and only when, they appear in all capitals, as shown here. 1.3. Tree Diagram Authors include a simplified graphical representation of the data model is used in Section 3 of this document. The meaning of the symbols in these diagrams is defined in [RFC8340]. 1.4. 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. Dios, et al. Expires 27 April 2023 [Page 3] Internet-Draft ISIS Topology YANG October 2022 +========+=======================+===========+ | Prefix | Yang Module | Reference | +========+=======================+===========+ | isisnt | ietf-l3-isis-topology | RFCXXX | +--------+-----------------------+-----------+ | yang | ietf-yang-types | [RFC6991] | +--------+-----------------------+-----------+ Table 1: Prefixes and corresponding YANG modules RFC Editor Note: Please replace XXXX with the RFC number assigned to this document. Please remove this note. 2. YANG Data Model for ISIS Topology The abstract (base) network data model is defined in the "ietf- network" module of [RFC8345]. The ISIS-topology builds on the network data model defined in the "ietf-network" module [RFC8345], 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 Dios, et al. Expires 27 April 2023 [Page 4] Internet-Draft ISIS Topology YANG October 2022 3. ISIS Topology Tree Diagram Figure 1 below shows the tree diagram of the YANG data model defined in module ietf-l3-isis-topology.yang (Section 4). module: ietf-l3-isis-topology augment /nw:networks/nw:network/nw:network-types: +--rw isis-topology! augment /nw:networks/nw:network/nw:node/l3t:l3-node-attributes: +--rw isis-timer-attributes | +--rw lsp-lifetime? string | +--rw lsp-refresh-interval? string +--rw isis-status +--rw level? ietf-isis:level +--rw area-address* ietf-isis:area-address +--ro neighbours* inet:ip-address augment .../nt:termination-point/l3t:l3-termination-point-attributes: +--rw isis-termination-point-attributes +--rw interface-type? identityref +--rw level? ietf-isis:level +--rw metric? uint64 +--rw is-passive? boolean Figure 1: ISIS Topology tree diagram 4. YANG Model for ISIS topology This module imports types from [RFC8343] and [RFC8345]. Following the YANG model is presented. file "ietf-l3-isis-topology@2022-10-24.yang" module ietf-l3-isis-topology { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-l3-isis-topology"; prefix "isisnt"; import ietf-network { prefix "nw"; reference "RFC 8345: A YANG Data Model for Network Topologies"; } import ietf-network-topology { prefix "nt"; reference "RFC 8345: A YANG Data Model for Network Topologies"; } Dios, et al. Expires 27 April 2023 [Page 5] Internet-Draft ISIS Topology YANG October 2022 import ietf-l3-unicast-topology { prefix "l3t"; reference "RFC 8346: A YANG Data Model for Layer 3 Topologies"; } import ietf-isis { prefix "ietf-isis"; reference "RFC 6991: Common YANG Data Types"; } import ietf-inet-types { prefix "inet"; reference "RFC 6991: Common YANG Data Types"; } organization "IETF OPSA (Operations and Management Area) Working Group"; contact "WG Web: 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."; Dios, et al. Expires 27 April 2023 [Page 6] Internet-Draft ISIS Topology YANG October 2022 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."; Dios, et al. Expires 27 April 2023 [Page 7] Internet-Draft ISIS Topology YANG October 2022 } 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"; Dios, et al. Expires 27 April 2023 [Page 8] Internet-Draft ISIS Topology YANG October 2022 } 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"; Dios, et al. Expires 27 April 2023 [Page 9] Internet-Draft ISIS Topology YANG October 2022 } description "Augments topology termination point configuration"; uses isis-termination-point-attributes; } } Figure 2: ISIS Topology YANG module 5. 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 [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 [RFC5246]. The NETCONF access control model [RFC6536] 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. 6. IANA Considerations This document registers the following namespace URIs in the IETF XML registry [RFC3688]: -------------------------------------------------------------------- URI: urn:ietf:params:xml:ns:yang:ietf-l3-isis-topology Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace. -------------------------------------------------------------------- This document registers the following YANG module in the YANG Module Names registry [RFC6020]: Dios, et al. Expires 27 April 2023 [Page 10] Internet-Draft ISIS Topology YANG October 2022 -------------------------------------------------------------------- name: ietf-l3-isis-topology namespace: urn:ietf:params:xml:ns:yang:ietf-l3-isis-topology maintained by IANA: N prefix: ietf-l3-isis-topology reference: RFC XXXX -------------------------------------------------------------------- 7. 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. 8. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, . [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.2", RFC 5246, DOI 10.17487/RFC5246, August 2008, . [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [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, . [RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011, . [RFC6536] Bierman, A. and M. Bjorklund, "Network Configuration Protocol (NETCONF) Access Control Model", RFC 6536, DOI 10.17487/RFC6536, March 2012, . Dios, et al. Expires 27 April 2023 [Page 11] Internet-Draft ISIS Topology YANG October 2022 [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013, . [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, . [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, . [RFC8343] Bjorklund, M., "A YANG Data Model for Interface Management", RFC 8343, DOI 10.17487/RFC8343, March 2018, . [RFC8345] Clemm, A., Medved, J., Varga, R., Bahadur, N., Ananthakrishnan, H., and X. Liu, "A YANG Data Model for Network Topologies", RFC 8345, DOI 10.17487/RFC8345, March 2018, . [RFC8346] Clemm, A., Medved, J., Varga, R., Liu, X., Ananthakrishnan, H., and N. Bahadur, "A YANG Data Model for Layer 3 Topologies", RFC 8346, DOI 10.17487/RFC8346, March 2018, . [RFC8795] Liu, X., Bryskin, I., Beeram, V., Saad, T., Shah, H., and O. Gonzalez de Dios, "YANG Data Model for Traffic Engineering (TE) Topologies", RFC 8795, DOI 10.17487/RFC8795, August 2020, . Dios, et al. Expires 27 April 2023 [Page 12] Internet-Draft ISIS Topology YANG October 2022 [RFC8944] Dong, J., Wei, X., Wu, Q., Boucadair, M., and A. Liu, "A YANG Data Model for Layer 2 Network Topologies", RFC 8944, DOI 10.17487/RFC8944, November 2020, . 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). Authors' Addresses Oscar González de Dios Telefonica Email: oscar.gonzalezdedios@telefonica.com Samier Barguil Telefonica Email: samier.barguilgiraldo.ext@telefonica.com Victor Lopez Nokia Email: victor.lopez@nokia.com Dios, et al. Expires 27 April 2023 [Page 13]