YANGmallit

YANGmallit are data models written in the YANG language that describe how network devices and services should store and expose configuration and state information. They specify hierarchical data structures along with constraints, enabling automated configuration, validation, and telemetry across vendors and platforms.

YANG was developed by the IETF NETMOD working group to provide a vendor-neutral model language for device management. The language was first published in RFC 6020 and has been updated with YANG 1.1 in RFC 7950 and related documents. YANG models are designed for use with management protocols such as NETCONF and RESTCONF and can be extended through additional modules and augmentations to cover new data types and capabilities.

Core concepts in YANGmallit include modules and submodules, containers, lists, and leaves as the primary data nodes. Leaf-lists, choice and when enhance conditional structures, while typedefs, identities, grouping, and uses promote reuse and clarity. Modules may import or include other modules, allowing a layered, composable model. YANG models can also define operations (RPCs) and notifications to support device management and event reporting.

Usage and impact: YANGmallit are used to standardize how configurations and operational data are represented, enabling interoperability between devices from different vendors and management systems. Prominent examples include IETF-maintained models such as ietf-interfaces and ietf-ip, as well as OpenConfig models that target vendor-neutral interface and telemetry definitions. They underpin configuration, validation, and telemetry workflows in many contemporary networks.

Tools and ecosystem: A range of tooling supports YANGmallit, including pyang for validation and code generation, yanglint for schema checking, and libraries such as libyang and bindings for various programming languages to parse and work with YANG models.