ArcObjects Library Reference (NetworkAnalyst)  

IGPNALayerType Interface

Provides access to properties/methods of the geoprocessing network analyst layer type.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server. Requires Network Analyst Extension.

CoClasses that implement IGPNALayerType

CoClasses and Classes Description
GPNALayerType Geoprocessing network analyst layer data type.