The HasLowerLayerInterface ReferenceTypeis a concrete ReferenceTypeand can be used directly. It is a subtype of HierarchicalReferences ReferenceType.

The usage of the Referencesis following the YANG modelling approach which is using reference pointers in the YANG-interface nodes to point to other interface nodes in lower or higher layers (“lower-layer-if”, “higher-layer-if”); see also RFC 8343.

Virtual interfaces shall reference their physical interfaces with the HasLowerLayerInterfaceReferenceType. Annex Annex Acontains examples for such hierarchical references.

The SourceNodeof this ReferenceTypeshall be an Objectorganized in the NetworkInterfacesfolder.

The TargetNodeof this ReferenceTypeshall be an Objectorganized in the NetworkInterfacesfolder.

The HasLowerLayerInterface ReferenceTypeis formally defined in Table 54.

Table 54– HasLowerLayerInterfacedefinition

Attributes	Value
BrowseName	HasLowerLayerInterface
InverseName	HasHigherLayerInterface
Symmetric	False
IsAbstract	False
References	NodeClass	BrowseName	Comment
Subtype of the HierarchicalReferences ReferenceType defined in OPC 10000-5
Conformance Units
BNM IETF Interface Base Info