Define host name-to-Kerberos realm mappings
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\System\Kerberos Description
This policy setting allows you to specify which DNS host names and which DNS suffixes are mapped to a Kerberos realm. If you enable this policy setting, you can view and change the list of DNS host names and DNS suffixes mapped to a Kerberos realm as defined by Group Policy. To view the list of mappings, enable the policy setting and then click the Show button. To add a mapping, enable the policy setting, note the syntax, and then click Show. In the Show Contents dialog box in the Value Name column, type a realm name. In the Value column, type the list of DNS host names and DNS suffixes using the appropriate syntax format. To remove a mapping from the list, click the mapping entry to be removed, and then press the DELETE key. To edit a mapping, remove the current entry from the list and add a new one with different parameters. If you disable this policy setting, the host name-to-Kerberos realm mappings list defined by Group Policy is deleted. If you do not configure this policy setting, the system uses the host name-to-Kerberos realm mappings that are defined in the local registry, if they exist.
Registry
Software\Microsoft\Windows\CurrentVersion\Policies\System\Kerberos Value name: domain_realm_Enabled
MDM / Intune (CSP)
./Device/Vendor/MSFT/Policy/Config/ADMX_Kerberos/HostToRealm 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: Define host name-to-Kerberos realm mappings
; State: Enabled
; Supported on: At least Windows Vista
[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\System\Kerberos]
"domain_realm_Enabled"=dword:00000001
[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\System\Kerberos\domain_realm]
; List values: enter one value per line in the builder UI.More formats (PowerShell, Intune, SCCM)
PowerShell
# Exported from gporais.com
# Policy: Define host name-to-Kerberos realm mappings
# State: Enabled
# Supported on: At least Windows Vista
$path = 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\Kerberos'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'domain_realm_Enabled' -Value 1 -Type DWord
$path = 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\Kerberos\domain_realm'
New-Item -Path $path -Force | Out-Null
# List values: enter one value per line in the builder UI.Intune XML
OMA-URI: ./Device/Vendor/MSFT/Policy/Config/ADMX_Kerberos/HostToRealm
Data type: String
Value:
<enabled/>
<!-- hosttorealm: enter one value per line before copying this XML payload. -->Intune Remediation
# === Detection script ===
# Exported from gporais.com
# Policy: Define host name-to-Kerberos realm mappings
# 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
}
# HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\Kerberos\domain_realm: List values: enter one value per line in the builder UI.
$checks = @(
(Test-RegistryValue -Path 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\Kerberos' -Name 'domain_realm_Enabled' -Expected 1 -Kind DWord)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Define host name-to-Kerberos realm mappings
# State: Enabled
# Supported on: At least Windows Vista
$path = 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\Kerberos'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'domain_realm_Enabled' -Value 1 -Type DWord
$path = 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\Kerberos\domain_realm'
New-Item -Path $path -Force | Out-Null
# List values: enter one value per line in the builder UI.SCCM scripts
# Exported from gporais.com
# Policy: Define host name-to-Kerberos realm mappings
# 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: Define host name-to-Kerberos realm mappings
# 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
}
# HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\Kerberos\domain_realm: List values: enter one value per line in the builder UI.
$checks = @(
(Test-RegistryValue -Path 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\Kerberos' -Name 'domain_realm_Enabled' -Expected 1 -Kind DWord)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Define host name-to-Kerberos realm mappings
# State: Enabled
# Supported on: At least Windows Vista
$path = 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\Kerberos'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'domain_realm_Enabled' -Value 1 -Type DWord
$path = 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\Kerberos\domain_realm'
New-Item -Path $path -Force | Out-Null
# List values: enter one value per line in the builder UI.Building a multi-setting collection? Add this setting and generate combined .reg / PowerShell / GPO scripts.