(L2) Ensure 'Turn on Mapper I/O (LLTDIO) driver' is set to 'Disabled'


This policy setting changes the operational behavior of the Mapper I/O network protocol driver.

LLTDIO allows a computer to discover the topology of a network it's connected to. It also allows a computer to initiate Quality-of-Service requests such as bandwidth estimation and network health analysis.

The recommended state for this setting is: Disabled

To help protect from potentially discovering and connecting to unauthorized devices, this setting should be disabled to prevent responding to network traffic for network topology discovery.


To establish the recommended configuration via GP, set the following UI path to Disabled :

Computer Configuration\Policies\Administrative Templates\Network\Link-Layer Topology Discovery\Turn on Mapper I/O (LLTDIO) driver

Note: This Group Policy path is provided by the Group Policy template LinkLayerTopologyDiscovery.admx/adml that is included with all versions of the Microsoft Windows Administrative Templates.


None - this is the default behavior.

See Also


Item Details


References: 800-53|CM-6, CSCv7|5.1

Plugin: Windows

Control ID: 611a1a6c7b0ccfee477a9cca126654612a4d473f8be8ee5e868b7fb9d3e531d7