The Mapper I/O network protocol (LLTDIO) driver must be disabled.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-15696	WN12-CC-000001	SV-53072r1_rule		Medium

Description
The Mapper I/O network protocol (LLTDIO) driver allows the discovery of the connected network and allows various options to be enabled. Disabling this helps protect the system from potentially discovering and connecting to unauthorized devices.

STIG	Date
Windows Server 2012/2012 R2 Domain Controller Security Technical Implementation Guide	2020-06-16

Details

Check Text ( C-47378r2_chk )
If the following registry values do not exist or are not configured as specified, this is a finding: Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \Software\Policies\Microsoft\Windows\LLTD\ Value Name: AllowLLTDIOOndomain Value Name: AllowLLTDIOOnPublicNet Value Name: EnableLLTDIO Value Name: ProhibitLLTDIOOnPrivateNet Type: REG_DWORD Value: 0

Fix Text (F-45998r1_fix)
Configure the policy value for Computer Configuration -> Administrative Templates -> Network -> Link-Layer Topology Discovery -> "Turn on Mapper I/O (LLTDIO) driver" to "Disabled".