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.If you enable this policy setting additional options are available to fine-tune your selection. You may choose the "Allow operation while in domain" option to allow LLTDIO to operate on a network interface that's connected to a managed network. On the other hand if a network interface is connected to an unmanaged network you may choose the "Allow operation while in public network" and "Prohibit operation while in private network" options instead.If you disable or do not configure this policy setting the default behavior of LLTDIO will apply.
Network\Link-Layer Topology Discovery
At least Windows Vista
HKLM\Software\Policies\Microsoft\Windows\LLTD!EnableLLTDIO; HKLM\Software\Policies\Microsoft\Windows\LLTD!AllowLLTDIOOnDomain HKLM\Software\Policies\Microsoft\Windows\LLTD!AllowLLTDIOOnPublicNet HKLM\Software\Policies\Microsoft\Windows\LLTD!ProhibitLLTDIOOnPrivateNet