INSA-Lyon

Lyon France alex.huang-feng@insa-lyon.fr

INSA-Lyon

Lyon France pierre.francois@insa-lyon.fr

Watsen Networks

kent+ietf@watsen.net

OPS netconf This document presents two YANG 1.1 modules with reusable groupings for managing UDP clients and UDP servers.

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 .

Copyright Notice Copyright (c) 2026 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 () 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

• .  Introduction
  • .  Requirements Language
  • .  Adherence to the NMDA
  • .  Conventions
• .  The "ietf-udp-client" Module
  • .  Data Model Overview
  • .  Example Usage
  • .  YANG Module
• .  The "ietf-udp-server" Module
  • .  Data Model Overview
  • .  Example Usage
  • .  YANG Module
• .  Security Considerations
• .  IANA Considerations
  • .  The "IETF XML Registry"
  • .  The "YANG Module Names" Registry
• .  References
  • .  Normative References
  • .  Informative References
• Acknowledgements
• Authors' Addresses

Introduction This document presents two YANG 1.1 modules with reusable groupings for managing UDP clients and UDP servers . These modules may be used directly (e.g., define a specific UDP client or UDP server) or in conjunction with the configuration defined for higher-level protocols that depend on UDP.

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 when, and only when, they appear in all capitals, as shown here.

Adherence to the NMDA This document is compliant with the Network Management Datastore Architecture (NMDA) . It does not define any protocol-accessible nodes that are "config false".

Conventions Various examples in this document use the XML encoding. Other encodings, such as JSON , could alternatively be used.

The "ietf-udp-client" Module This section defines a YANG 1.1 module called "ietf-udp-client". This YANG module defines the "udp-client" grouping for providing UDP clients with remote server information. provides the overview of the YANG module. An example of usage is illustrated in . defines the YANG module itself.

Data Model Overview This section provides an overview of the features and the grouping defined in the "ietf-udp-client" YANG module.

Features The "ietf-udp-client" module defines the following "feature" statement: Features: +-- local-binding The diagram above uses syntax that is similar to the syntax used in ; but the syntax from the diagram is not defined in . This feature indicates that the client supports configuring local bindings (i.e., the local address and local port number) for UDP clients.

The "udp-client" Grouping The following tree diagram illustrates the tree structure of the "udp-client" grouping: module: ietf-udp-client grouping udp-client: +-- remote-address inet:host +-- remote-port? inet:port-number +-- local-address? inet:ip-address {local-binding}? +-- local-port? inet:port-number {local-binding}? The description of these parameters is provided below:

• The "remote-address", which is mandatory, may be configured as an IPv4 address, an IPv6 address, or a hostname. The resolved address should be compatible with the local address family, if also provided.
• The "remote-port" is defined with neither a "default" nor a "mandatory" statement. YANG modules using this grouping SHOULD refine the grouping with a "default" statement when the port number is well-known (e.g., a port number allocated by IANA) or with a "mandatory" statement if a port number needs to always be configured. This MAY be ignored when the port number is neither well-known nor mandatory to configure, such as might be the case when this grouping is used by another grouping.
• The "local-address", which is enabled by the "local-binding" feature, may be configured as an IPv4 address, an IPv6 address, or a wildcard value. In normal operation, the local and configured remote addresses SHOULD be from the same address family. Differences between address families may occur in abnormal or error conditions; therefore, they are allowed to be reported.
• The "local-port", which depends on the "local-binding" feature, is not mandatory. Its default value is "0", indicating that the operating system can select an arbitrary port number.

Example Usage This section presents an example of usage of the "udp-client" grouping. <!-- The outermost element below doesn't exist in the data model. --> <!-- It simulates if the "grouping" were a "container" instead. --> <udp-client xmlns="urn:ietf:params:xml:ns:yang:ietf-udp-client"> <remote-address>www.example.com</remote-address> <remote-port>10000</remote-port> <local-address>192.0.2.2</local-address> <local-port>12345</local-port> </udp-client>

YANG Module This module imports types defined in . module ietf-udp-client { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-udp-client"; prefix udpc; import ietf-inet-types { prefix inet; reference "RFC 9911: Common YANG Data Types"; } organization "IETF NETCONF (Network Configuration) Working Group"; contact "WG Web: <https://datatracker.ietf.org/group/netconf/> WG List: <mailto:netconf@ietf.org> Authors: Alex Huang Feng <mailto:alex.huang-feng@insa-lyon.fr> Pierre Francois <mailto:pierre.francois@insa-lyon.fr>"; description "Defines a generic grouping for UDP-based client applications. 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. Copyright (c) 2026 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). All revisions of IETF and IANA published modules can be found at the YANG Parameters registry group (https://www.iana.org/assignments/yang-parameters). This version of this YANG module is part of RFC 9984; see the RFC itself for full legal notices."; revision 2026-06-15 { description "Initial revision"; reference "RFC 9984: YANG Groupings for UDP Clients and UDP Servers"; } feature local-binding { description "Indicates that the UDP client supports configuring local bindings (i.e., the local address and local port number) for UDP clients."; } grouping udp-client { description "A reusable grouping for UDP clients. Note that this grouping uses fairly typical descendant node names such that a stack of 'uses' statements will have name conflicts. It is intended that the consuming data model will resolve the issue (e.g., by wrapping the 'uses' statement in a container called 'udp-client-parameters'). This module purposely does not do this itself so as to provide maximum flexibility to consuming models."; leaf remote-address { type inet:host; mandatory true; description "The IP address or hostname of the remote UDP server."; } leaf remote-port { type inet:port-number; description "The port number of the remote UDP server."; } leaf local-address { if-feature "local-binding"; type inet:ip-address; description "The local IP address to bind to when sending UDP datagrams to the remote server. INADDR_ANY ('0.0.0.0') or INADDR6_ANY ('0:0:0:0:0:0:0:0' a.k.a. '::') may be used so that the client can bind to any IPv4 or IPv6 address. In normal operation, the local and configured remote addresses SHOULD be from the same address family. Differences between address families may occur in abnormal or error conditions; therefore, they are allowed to be reported."; } leaf local-port { if-feature "local-binding"; type inet:port-number; default "0"; description "The local port number to bind to when sending UDP datagrams to the remote server. The port number '0', which is the default value, indicates that any available local port number may be used."; } } }

The "ietf-udp-server" Module This section defines a YANG 1.1 module called "ietf-udp-server". This YANG module defines the "udp-server" grouping for managing UDP servers. provides an overview of the "ietf-udp-server" YANG module. An example of usage is illustrated in . defines the YANG module itself.

Data Model Overview This section provides an overview of the grouping defined in the "ietf-udp-server" module.

The "udp-server" Grouping The following tree diagram illustrates the tree structure of "udp-server" grouping: module: ietf-udp-server grouping udp-server: +-- local-bind* [local-address] +-- local-address inet:ip-address +-- local-port? inet:port-number The description of these parameters is provided below:

• The "local-address", which is mandatory, may be configured as an IPv4 address, an IPv6 address, or a wildcard value.
• The "local-port" is defined with neither a "default" nor a "mandatory" statement. YANG modules using this grouping SHOULD refine the grouping with a "default" statement when the port number is well-known (e.g., a port number allocated by IANA) or with a "mandatory" statement if a port number needs to always be configured. This MAY be ignored when the port number is neither well-known nor mandatory to configure, such as might be the case when this grouping is used by another grouping.

Example Usage This section presents two examples of usage of the "udp-server" grouping. The following shows an example of a server configured for listening to an IPv4 address: <!-- The outermost element below doesn't exist in the data model. --> <!-- It simulates if the "grouping" were a "container" instead. --> <udp-server xmlns="urn:ietf:params:xml:ns:yang:ietf-udp-server"> <local-bind> <local-address>192.0.2.2</local-address> <local-port>49152</local-port> </local-bind> </udp-server> The following shows an example of a server configured for listening to an IPv4 and IPv6 together: <!-- The outermost element below doesn't exist in the data model. --> <!-- It simulates if the "grouping" were a "container" instead. --> <udp-server xmlns="urn:ietf:params:xml:ns:yang:ietf-udp-server"> <local-bind> <local-address>192.0.2.2</local-address> <local-port>49152</local-port> </local-bind> <local-bind> <local-address>2001:db8::0</local-address> <local-port>49153</local-port> </local-bind> </udp-server>

YANG Module This module imports types defined in . module ietf-udp-server { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-udp-server"; prefix udps; import ietf-inet-types { prefix inet; reference "RFC 9911: Common YANG Data Types"; } organization "IETF NETCONF (Network Configuration) Working Group"; contact "WG Web: <https://datatracker.ietf.org/group/netconf/> WG List: <mailto:netconf@ietf.org> Authors: Alex Huang Feng <mailto:alex.huang-feng@insa-lyon.fr> Pierre Francois <mailto:pierre.francois@insa-lyon.fr>"; description "Defines a generic grouping for UDP-based server applications. Copyright (c) 2026 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). All revisions of IETF and IANA published modules can be found at the YANG Parameters registry group (https://www.iana.org/assignments/yang-parameters). This version of this YANG module is part of RFC 9984; see the RFC itself for full legal notices."; revision 2026-06-15 { description "Initial revision"; reference "RFC 9984: YANG Groupings for UDP Clients and UDP Servers"; } grouping udp-server { description "A reusable grouping for managing UDP servers. Note that this grouping uses fairly typical descendant node names such that a stack of 'uses' statements will have name conflicts. It is intended that the consuming data model will resolve the issue (e.g., by wrapping the 'uses' statement in a container called 'udp-server-parameters'). This module purposely does not do this itself so as to provide maximum flexibility to consuming models."; list local-bind { key "local-address"; min-elements 1; description "A list of bind (listen) points for this server instance. A server instance may have multiple bind points to support, e.g., the same port number in different address families or different port numbers in the same address family."; leaf local-address { type inet:ip-address; mandatory true; description "The local IP address to listen on for incoming UDP datagrams. INADDR_ANY ('0.0.0.0') or INADDR6_ANY ('0:0:0:0:0:0:0:0' a.k.a. '::') may be used so that the server can listen to any IPv4 or IPv6 address."; } leaf local-port { type inet:port-number; description "The local port number to listen on for incoming UDP datagrams."; } } } }

Security Considerations This section uses the template described in . The "ietf-udp-client" and "ietf-udp-server" YANG modules define a data model that is designed to be accessed via YANG-based management protocols, such as the Network Configuration Protocol (NETCONF) and RESTCONF . These YANG-based management protocols (1) have to use a secure transport layer (e.g., Secure Shell (SSH) , TLS , and QUIC ) and (2) have to use mutual authentication. The Network Configuration Access Control Model (NACM) 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. These YANG modules define a set of identities, types, and groupings. These nodes are intended to be reused by other YANG modules. The modules by themselves do not expose any data nodes that are writable, data nodes that contain read-only state, or RPCs. As such, there are no additional security issues related to the YANG modules that need to be considered. Modules that use the groupings that are defined in this document should identify the corresponding security considerations. For example, reusing some of these groupings will expose privacy-related information (e.g., 'remote-address', 'remote-port', 'local-address', or 'local-port').

IANA Considerations This document describes the URIs from the "IETF XML Registry" and the registration of two new YANG module names.

The "IETF XML Registry" IANA has assigned two new URIs from the "IETF XML Registry":

URI:

urn:ietf:params:xml:ns:yang:ietf-udp-client

Registrant Contact:

The IESG.

XML:

N/A; the requested URI is an XML namespace.

URI:

urn:ietf:params:xml:ns:yang:ietf-udp-server

Registrant Contact:

The IESG.

XML:

N/A; the requested URI is an XML namespace.

The "YANG Module Names" Registry IANA has registered the following YANG modules in the "YANG Module Names" registry within the "YANG Parameters" registry group:

Name:

ietf-udp-client

Maintained by IANA?

N

Namespace:

urn:ietf:params:xml:ns:yang:ietf-udp-client

Prefix:

udpc

Reference:

RFC 9984

Name:

ietf-udp-server

Maintained by IANA?

N

Namespace:

urn:ietf:params:xml:ns:yang:ietf-udp-server

Prefix:

udps

Reference:

RFC 9984

References Normative References 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. 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] 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). 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. The standardization of network configuration interfaces for use with the Network Configuration Protocol (NETCONF) or the RESTCONF protocol 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 or RESTCONF protocol access for particular users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content. This document defines such an access control model. This document obsoletes RFC 6536. This document defines a collection of common data types to be used with the YANG data modeling language. It includes several new type definitions and obsoletes RFC 6991. Informative References The Secure Shell Protocol (SSH) is a protocol for secure remote login and other secure network services over an insecure network. This document describes the SSH authentication protocol framework and public key, password, and host-based client authentication methods. Additional authentication methods are described in separate documents. The SSH authentication protocol runs on top of the SSH transport layer protocol and provides a single authenticated tunnel for the SSH connection protocol. [STANDARDS-TRACK] 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). JavaScript Object Notation (JSON) is a lightweight, text-based, language-independent data interchange format. It was derived from the ECMAScript Programming Language Standard. JSON defines a small set of formatting rules for the portable representation of structured data. This document removes inconsistencies with other specifications of JSON, repairs specification errors, and offers experience-based interoperability guidance. 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. 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. This document specifies version 1.3 of the Transport Layer Security (TLS) protocol. TLS allows client/server applications to communicate over the Internet in a way that is designed to prevent eavesdropping, tampering, and message forgery. This document updates RFCs 5705 and 6066, and obsoletes RFCs 5077, 5246, and 6961. This document also specifies new requirements for TLS 1.2 implementations. This document defines the core of the QUIC transport protocol. QUIC provides applications with flow-controlled streams for structured communication, low-latency connection establishment, and network path migration. QUIC includes security measures that ensure confidentiality, integrity, and availability in a range of deployment circumstances. Accompanying documents describe the integration of TLS for key negotiation, loss detection, and an exemplary congestion control algorithm. This document provides guidelines for authors and reviewers of specifications containing YANG data models, including IANA-maintained YANG modules. Recommendations and procedures are defined, which are intended to increase interoperability and usability of Network Configuration Protocol (NETCONF) and RESTCONF protocol implementations that utilize YANG modules. This document obsoletes RFC 8407; it also updates RFC 8126 by providing additional guidelines for writing the IANA considerations for RFCs that specify IANA-maintained YANG modules. W3C Recommendation Latest version available at .

Acknowledgements The authors would like to thank , , , , , , , , , and for their reviews and valuable comments.

Authors' Addresses INSA-Lyon

Lyon France alex.huang-feng@insa-lyon.fr

INSA-Lyon

Lyon France pierre.francois@insa-lyon.fr

Watsen Networks

kent+ietf@watsen.net