The Link-Layer Topology Discovery Mapper (lltdsvc) service creates a network map, which includes computer and device connectivity information and metadata that describes each computer and device. If this service is disabled, the network map does not function properly.

This service is installed by default and its startup type is Manual. When the Link-Layer Topology Discovery Mapper service is started in its default configuration, it logs on by using the Local Service account.

The Link-Layer Topology Discovery Mapper service is dependent upon the following system components:

• Link-Layer Topology Discovery Mapper I/O Driver
• Remote Procedure Call (RPC)
• DCOM Server Process Launcher
• RPC Endpoint Mapper