Internet Y. Qu Internet-Draft Futurewei Technologies Intended status: Standards Track A. Lindem Expires: 27 July 2024 LabN Consulting, L.L.C. S. Litkowski Cisco Systems J. Tantsura Nvidia 24 January 2024 A YANG Model for MPLS MSD draft-ietf-mpls-msd-yang-05 Abstract This document defines a YANG data model augmenting the IETF MPLS YANG model to provide support for MPLS Maximum SID Depths (MSDs) as defined in RFC 8476 and RFC 8491. 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." This Internet-Draft will expire on 27 July 2024. Copyright Notice Copyright (c) 2024 IETF Trust and the persons identified as the document authors. All rights reserved. Qu, et al. Expires 27 July 2024 [Page 1] Internet-Draft MPLS MSD YANG January 2024 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. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 2. Design of the Model . . . . . . . . . . . . . . . . . . . . . 3 2.1. IANA MSD Types Module . . . . . . . . . . . . . . . . . . 3 2.2. IETF MPLS MSD Types Module . . . . . . . . . . . . . . . 3 3. Tree for IETF MPLS MSD Types YANG Module . . . . . . . . . . 3 4. YANG Modules . . . . . . . . . . . . . . . . . . . . . . . . 4 5. Security Considerations . . . . . . . . . . . . . . . . . . . 9 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 8.1. Normative References . . . . . . . . . . . . . . . . . . 11 8.2. Informative References . . . . . . . . . . . . . . . . . 12 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12 1. Overview YANG [RFC7950] is a data definition language used to define the contents of a conceptual data store that allows networked devices to be managed using NETCONF [RFC6241] or RESTCONF [RFC8040]. There are two YANG modules defined in this document. Module iana- msd-types defines the identities for Maximum SID Depth (MSD) Types as the IANA the IGP MSD-Types registry. This document also defines module ietf-mpls-msd augmenting the IETF MPLS YANG model [RFC8960], which itself augments [RFC8349], to provide operational state for various MSDs[RFC8662]. The module augments the base MPLS model with a list of various types of node MSDs, as well as various types of MSDs on links. The augmentation defined in this document requires support for the MPLS base model[RFC8960] which defines basic MPLS configuration and state. The YANG modules in this document conform to the Network Management Datastore Architecture (NMDA) [RFC8342]. Qu, et al. Expires 27 July 2024 [Page 2] Internet-Draft MPLS MSD YANG January 2024 1.1. 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 BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. 2. Design of the Model 2.1. IANA MSD Types Module Module iana-msd-types is an IANA maintained module, which defines the identities in the IANA IGP MSD-Types registry. On top of the base identity "msd-base", identity "msd-base-mpls" is defined to serve as the base for MSD types for MPLS data plane, and identity "msd-base-srh" is defined to serve as the base for MSD types for Segment Routing Header (SRH) in IPv6 data plane. This module will be maintained by IANA if more MSD types are added to the registry. 2.2. IETF MPLS MSD Types Module Module ietf-mpls-msd augments the base MPLS model [RFC8960], and it is to provide support of different types of MSDs in MPLS data plane. As defined in [RFC8491], MSD is the number of SIDs supported by a node or a link on a node. The module defines lists of MSDs with different MSD Types for a node and links. Please note that these are read-only data decided by the node's hardware capability. 3. Tree for IETF MPLS MSD Types YANG Module This document uses the graphical representation of data models per [RFC8340]. Qu, et al. Expires 27 July 2024 [Page 3] Internet-Draft MPLS MSD YANG January 2024 module: ietf-mpls-msd augment /rt:routing/mpls:mpls: +--ro node-msd +--ro node-msds* [msd-type] +--ro msd-type? identityref +--ro msd-value? uint8 augment /rt:routing/mpls:mpls/mpls:interfaces/mpls:interface: +--ro link-msd +--ro link-msds* [msd-type] +--ro msd-type? identityref +--ro msd-value? uint8 4. YANG Modules This document defines an IANA YANG module for MSD Types defined in the IANA IGP MSD-Types registry. file "iana-msd-types@2024-01-24.yang" module iana-msd-types { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:iana-msd-types"; prefix iana-msd-types; organization "IANA"; contact "Internet Assigned Numbers Authority Postal: ICANN 12025 Waterfront Drive, Suite 300 Los Angeles, CA 90094-2536 United States of America Tel: +1 310 301 5800 "; description "The YANG module defines the identities for Maximum SID Depth (MSD) Types. Copyright (c) 2024 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Revised BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info). Qu, et al. Expires 27 July 2024 [Page 4] Internet-Draft MPLS MSD YANG January 2024 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 2024-01-24 { description "Initial Version"; reference "RFC XXXX: A YANG Data Model for MPLS MSD.."; } identity msd-base { description "Base identity for Maximum SID Depth (MSD) Type. The MSD type definition is defined in IANA IGP MSD-Types registry."; } identity msd-base-mpls { base msd-base; description "Identity for MSD types applicable to MPLS data plane."; } identity msd-mpls { base msd-base-mpls; description "Base MPLS Imposition MSD."; reference "RFC 8491: Signaling Maximum SID Depth (MSD) using IS-IS RFC 8476: Signaling Maximum SID Depth (MSD) using OSPF RFC 8664: Path Computation Element Communication Protocol (PCEP) Extensions for Segment Routing RFC 8814: Signaling Maximum SID Depth (MSD) Using the Border Gateway Protocol - Link State"; } identity msd-erld { base msd-base-mpls; description "msd-erld is defined to advertise the Entropy Readable Label Depth (ERLD)."; reference "RFC 8662: Entropy Label for Source Packet Routing in Networking (SPRING) Tunnels"; } identity msd-base-srh { base msd-base; Qu, et al. Expires 27 July 2024 [Page 5] Internet-Draft MPLS MSD YANG January 2024 description "Identity for MSD types for Segment Routing Header (SRH)."; } identity msd-srh-max-sl { base msd-base-srh; description "The Maximum Segment Left MSD type."; reference "RFC 9352: IS-IS Extensions to Support Segment Routing over the IPv6 Data Plane"; } identity msd-srh-max-end-pop { base msd-base-srh; description "The Maximum End Pop MSD Type."; reference "RFC 9352: IS-IS Extensions to Support Segment Routing over the IPv6 Data Plane"; } identity msd-srh-max-hen-cap { base msd-base-srh; description "The Maximum H.Encaps MSD Type."; reference "RFC 9352: IS-IS Extensions to Support Segment Routing over the IPv6 Data Plane"; } identity msd-srh-max-end-d { base msd-base-srh; description "The Maximum End D MSD Type."; reference "RFC 9352: IS-IS Extensions to Support Segment Routing over the IPv6 Data Plane"; } } This document also defines a YANG module for MSD extensions [RFC8476][RFC8491] to MPLS base model as defined in [RFC8960]. Qu, et al. Expires 27 July 2024 [Page 6] Internet-Draft MPLS MSD YANG January 2024 file "ietf-mpls-msd@2024-01-24.yang" module ietf-mpls-msd { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-mpls-msd"; prefix mpls-msd; import ietf-routing { prefix rt; reference "RFC 8349: A YANG Data Model for Routing Management (NMDA Version)"; } import ietf-mpls { prefix mpls; reference "RFC 8960: A YANG Data Model for MPLS Base"; } import iana-msd-types { prefix iana-msd-types; } organization "IETF Multiprotocol Label Switching (MPLS) Working Group"; contact "WG Web: WG List: Author: Yingzhen Qu Author: Acee Lindem Author: Stephane Litkowski Author: Jeff Tantsura "; description "The YANG module augments the base MPLS model, and it is to provide support for different types of Maximum SID Depth (MSD). This YANG model conforms to the Network Management Datastore Architecture (NMDA) as described in RFC 8342. Copyright (c) 2024 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or Qu, et al. Expires 27 July 2024 [Page 7] Internet-Draft MPLS MSD YANG January 2024 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; see the RFC itself for full legal notices. The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'NOT RECOMMENDED', 'MAY', and 'OPTIONAL' in this document are to be interpreted as described in BCP 14 (RFC 2119) (RFC 8174) when, and only when, they appear in all capitals, as shown here."; reference "RFC XXXX: A YANG Data Model for MPLS MSD."; revision 2024-01-24 { description "Initial Version"; reference "RFC XXXX: A YANG Data Model for MPLS MSD."; } grouping msd-type-value { description "Grouping for MSD type and value."; leaf msd-type { type identityref { base iana-msd-types:msd-base-mpls; } mandatory true; description "MSD types. The MSD type is defined in IANA IGP MSD-Types registry."; } leaf msd-value { type uint8; mandatory true; description "MSD value, in the range of 0-255."; } } augment "/rt:routing/mpls:mpls" { description "This module augments MPLS data model (RFC 8960) with node MSD."; container node-msd { Qu, et al. Expires 27 July 2024 [Page 8] Internet-Draft MPLS MSD YANG January 2024 config false; description "Maximum SID Depth (MSD) of a node."; list node-msds { key "msd-type"; uses msd-type-value; description "List of different types of MSDs of the node. A type of Node MSD is the smallest same type link MSD supported by the node."; } } } augment "/rt:routing/mpls:mpls/mpls:interfaces/mpls:interface" { description "This module augments MPLS data model (RFC 8960) with link MSD."; container link-msd { config false; description "Maximum SID Depth (MSD) of an interface."; list link-msds { key "msd-type"; uses msd-type-value; description "List of different types of MSDs on the link."; } } } } 5. Security Considerations The YANG modules specified in this document define 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 [RFC8446]. The NETCONF Access Control Model (NACM) [RFC8341] provides the means to restrict access for particular NETCONF or RESTCONF users to a pre- configured subset of all available NETCONF or RESTCONF protocol operations and content. Qu, et al. Expires 27 July 2024 [Page 9] Internet-Draft MPLS MSD YANG January 2024 Some of the readable data nodes in the modules may be considered sensitive or vulnerable in some network environments. It is thus important to control read access (e.g., via get, get-config, or notification) to these data nodes. These are the subtrees and data nodes and their sensitivity/vulnerability: /rt:routing/mpls:mpls/msd/node-msds /rt:routing/mpls:mpls/msd/link-msds Exposure of the node's maximum SID depth may be useful in mounting a Denial-of-Service (DoS) attack by sending packets to the node that the router can't process. 6. IANA Considerations This document registers URIs in the IETF XML registry [RFC3688]. Following the format in [RFC3688], the following registrations is requested to be made: URI: urn:ietf:params:xml:ns:yang:iana-msd-types Registrant Contact: IANA. XML: N/A, the requested URI is an XML namespace. URI: urn:ietf:params:xml:ns:yang:ietf-mpls-msd Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace. This document registers the YANG modules in the YANG Module Names registry [RFC6020]. name: iana-msd-types namespace: urn:ietf:params:xml:ns:yang:iana-msd-types prefix: iana-msd-types reference: RFC XXXX name: ietf-mpls-msd namespace: urn:ietf:params:xml:ns:yang:ietf-mpls-msd prefix: mpls-msd reference: RFC XXXX Qu, et al. Expires 27 July 2024 [Page 10] Internet-Draft MPLS MSD YANG January 2024 7. Acknowledgements This document was produced using Marshall Rose's xml2rfc tool. The YANG model was developed using the suite of YANG tools written and maintained by numerous authors. We would like to thank Jan Lindblad, Tom Petch, and Susan Hares for their reviews and comments. 8. References 8.1. 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, . [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, . [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, . Qu, et al. Expires 27 July 2024 [Page 11] Internet-Draft MPLS MSD YANG January 2024 [RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, 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, . [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, . [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, . [RFC8476] Tantsura, J., Chunduri, U., Aldrin, S., and P. Psenak, "Signaling Maximum SID Depth (MSD) Using OSPF", RFC 8476, DOI 10.17487/RFC8476, December 2018, . [RFC8491] Tantsura, J., Chunduri, U., Aldrin, S., and L. Ginsberg, "Signaling Maximum SID Depth (MSD) Using IS-IS", RFC 8491, DOI 10.17487/RFC8491, November 2018, . [RFC8960] Saad, T., Raza, K., Gandhi, R., Liu, X., and V. Beeram, "A YANG Data Model for MPLS Base", RFC 8960, DOI 10.17487/RFC8960, December 2020, . 8.2. Informative References [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, . [RFC8662] Kini, S., Kompella, K., Sivabalan, S., Litkowski, S., Shakir, R., and J. Tantsura, "Entropy Label for Source Packet Routing in Networking (SPRING) Tunnels", RFC 8662, DOI 10.17487/RFC8662, December 2019, . Authors' Addresses Qu, et al. Expires 27 July 2024 [Page 12] Internet-Draft MPLS MSD YANG January 2024 Yingzhen Qu Futurewei Technologies Email: yingzhen.ietf@gmail.com Acee Lindem LabN Consulting, L.L.C. Email: acee.ietf@gmail.com Stephane Litkowski Cisco Systems Email: slitkows.ietf@gmail.com Jeff Tantsura Nvidia Email: jefftant.ietf@gmail.com Qu, et al. Expires 27 July 2024 [Page 13]