Turn on Mapper I/O (LLTDIO) driver
Verified with Windows 11 25H2 — updated on July 30, 2026
Supported on: At least Windows Vista
Path in the GPO console
Computer Configuration\Administrative Templates\Network\Link-Layer Topology Discovery Description
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.
Registry
HKLM
Software\Policies\Microsoft\Windows\LLTD Value name: EnableLLTDIO
Enabled: EnableLLTDIO = 1
Disabled: EnableLLTDIO = 0
MDM / Intune (CSP)
./Device/Vendor/MSFT/Policy/Config/ADMX_LinkLayerTopologyDiscovery/LLTD_EnableLLTDIO Microsoft Learn documentation Mapping data: Microsoft Learn (CC BY 4.0)
Export Builder
BETAConfigure the state, scope and options, then generate .reg, PowerShell, Intune and SCCM outputs — or add the setting to a multi-setting collection.
These exports write the registry — this is not a managed GPO. ⓘ
.reg file
Windows Registry Editor Version 5.00
; Exported from gporais.com
; Policy: Turn on Mapper I/O (LLTDIO) driver
; State: Enabled
; Supported on: At least Windows Vista
[HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\LLTD]
"EnableLLTDIO"=dword:00000001
"AllowLLTDIOOnDomain"=dword:00000000
"AllowLLTDIOOnPublicNet"=dword:00000000
"ProhibitLLTDIOOnPrivateNet"=dword:00000000More formats (PowerShell, Intune, SCCM)
PowerShell
# Exported from gporais.com
# Policy: Turn on Mapper I/O (LLTDIO) driver
# State: Enabled
# Supported on: At least Windows Vista
$path = 'HKLM:\Software\Policies\Microsoft\Windows\LLTD'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'EnableLLTDIO' -Value 1 -Type DWord
Set-ItemProperty -Path $path -Name 'AllowLLTDIOOnDomain' -Value 0 -Type DWord
Set-ItemProperty -Path $path -Name 'AllowLLTDIOOnPublicNet' -Value 0 -Type DWord
Set-ItemProperty -Path $path -Name 'ProhibitLLTDIOOnPrivateNet' -Value 0 -Type DWordIntune XML
OMA-URI: ./Device/Vendor/MSFT/Policy/Config/ADMX_LinkLayerTopologyDiscovery/LLTD_EnableLLTDIO
Data type: String
Value:
<enabled/>
<data id="LLTD_EnableLLTDIO_AllowOnDomain" value="0"/>
<data id="LLTD_EnableLLTDIO_AllowOnPublicNet" value="0"/>
<data id="LLTD_EnableLLTDIO_ProhibitOnPrivateNet" value="0"/>Intune Remediation
# === Detection script ===
# Exported from gporais.com
# Policy: Turn on Mapper I/O (LLTDIO) driver
# State: Enabled
# Supported on: At least Windows Vista
function Test-RegistryValue {
param(
[Parameter(Mandatory = $true)][string]$Path,
[Parameter(Mandatory = $true)][string]$Name,
[object]$Expected,
[ValidateSet('String', 'DWord', 'MultiString')][string]$Kind = 'String',
[switch]$Absent
)
try {
$item = Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction Stop
} catch {
return $Absent.IsPresent
}
if ($Absent.IsPresent) { return $false }
$actual = $item.$Name
if ($Kind -eq 'DWord') { return ([int64]$actual) -eq ([int64]$Expected) }
if ($Kind -eq 'MultiString') {
$actualValues = @($actual)
$expectedValues = @($Expected)
if ($actualValues.Count -ne $expectedValues.Count) { return $false }
for ($i = 0; $i -lt $expectedValues.Count; $i++) {
if ([string]$actualValues[$i] -ne [string]$expectedValues[$i]) { return $false }
}
return $true
}
return [string]$actual -eq [string]$Expected
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Windows\LLTD' -Name 'EnableLLTDIO' -Expected 1 -Kind DWord)
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Windows\LLTD' -Name 'AllowLLTDIOOnDomain' -Expected 0 -Kind DWord)
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Windows\LLTD' -Name 'AllowLLTDIOOnPublicNet' -Expected 0 -Kind DWord)
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Windows\LLTD' -Name 'ProhibitLLTDIOOnPrivateNet' -Expected 0 -Kind DWord)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Turn on Mapper I/O (LLTDIO) driver
# State: Enabled
# Supported on: At least Windows Vista
$path = 'HKLM:\Software\Policies\Microsoft\Windows\LLTD'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'EnableLLTDIO' -Value 1 -Type DWord
Set-ItemProperty -Path $path -Name 'AllowLLTDIOOnDomain' -Value 0 -Type DWord
Set-ItemProperty -Path $path -Name 'AllowLLTDIOOnPublicNet' -Value 0 -Type DWord
Set-ItemProperty -Path $path -Name 'ProhibitLLTDIOOnPrivateNet' -Value 0 -Type DWordSCCM scripts
# Exported from gporais.com
# Policy: Turn on Mapper I/O (LLTDIO) driver
# State: Enabled
# Supported on: At least Windows Vista
# SCCM Configuration Item guidance:
# Create a Configuration Item of type "Setting: Script".
# Discovery script: use the Detection script below.
# Remediation script: use the Remediation script below.
# Compliance rule: the Discovery script output equals 'Compliant'.
# === Detection script ===
# Exported from gporais.com
# Policy: Turn on Mapper I/O (LLTDIO) driver
# State: Enabled
# Supported on: At least Windows Vista
function Test-RegistryValue {
param(
[Parameter(Mandatory = $true)][string]$Path,
[Parameter(Mandatory = $true)][string]$Name,
[object]$Expected,
[ValidateSet('String', 'DWord', 'MultiString')][string]$Kind = 'String',
[switch]$Absent
)
try {
$item = Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction Stop
} catch {
return $Absent.IsPresent
}
if ($Absent.IsPresent) { return $false }
$actual = $item.$Name
if ($Kind -eq 'DWord') { return ([int64]$actual) -eq ([int64]$Expected) }
if ($Kind -eq 'MultiString') {
$actualValues = @($actual)
$expectedValues = @($Expected)
if ($actualValues.Count -ne $expectedValues.Count) { return $false }
for ($i = 0; $i -lt $expectedValues.Count; $i++) {
if ([string]$actualValues[$i] -ne [string]$expectedValues[$i]) { return $false }
}
return $true
}
return [string]$actual -eq [string]$Expected
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Windows\LLTD' -Name 'EnableLLTDIO' -Expected 1 -Kind DWord)
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Windows\LLTD' -Name 'AllowLLTDIOOnDomain' -Expected 0 -Kind DWord)
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Windows\LLTD' -Name 'AllowLLTDIOOnPublicNet' -Expected 0 -Kind DWord)
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Windows\LLTD' -Name 'ProhibitLLTDIOOnPrivateNet' -Expected 0 -Kind DWord)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Turn on Mapper I/O (LLTDIO) driver
# State: Enabled
# Supported on: At least Windows Vista
$path = 'HKLM:\Software\Policies\Microsoft\Windows\LLTD'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'EnableLLTDIO' -Value 1 -Type DWord
Set-ItemProperty -Path $path -Name 'AllowLLTDIOOnDomain' -Value 0 -Type DWord
Set-ItemProperty -Path $path -Name 'AllowLLTDIOOnPublicNet' -Value 0 -Type DWord
Set-ItemProperty -Path $path -Name 'ProhibitLLTDIOOnPrivateNet' -Value 0 -Type DWordBuilding a multi-setting collection? Add this setting and generate combined .reg / PowerShell / GPO scripts.