Windows Defender Firewall: Allow authenticated IPsec bypass
Verified with Windows 11 25H2 — updated on July 12, 2026
Supported on: At least Windows XP Professional with SP2
Path in the GPO console
Computer Configuration\Administrative Templates\Network\Network Connections\Windows Defender Firewall Description
Allows unsolicited incoming messages from specified systems that authenticate using the IPsec transport. If you enable this policy setting, you must type a security descriptor containing a list of computers or groups of computers. If a computer on that list authenticates using IPsec, Windows Defender Firewall does not block its unsolicited messages. This policy setting overrides other policy settings that would block those messages. If you disable or do not configure this policy setting, Windows Defender Firewall makes no exception for messages sent by computers that authenticate using IPsec. If you enable this policy setting and add systems to the list, upon disabling this policy, Windows Defender Firewall deletes the list. Note: You define entries in this list by using Security Descriptor Definition Language (SDDL) strings. For more information about the SDDL format, see the Windows Defender Firewall deployment information at the Microsoft Web site (http://go.microsoft.com/fwlink/?LinkId=25131).
Registry
SOFTWARE\Policies\Microsoft\Windows\IPSec\ICFv4 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: Windows Defender Firewall: Allow authenticated IPsec bypass
; State: Enabled
; Supported on: At least Windows XP Professional with SP2
[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\IPSec\ICFv4]
"BypassFirewall"=""More formats (PowerShell, Intune, SCCM)
PowerShell
# Exported from gporais.com
# Policy: Windows Defender Firewall: Allow authenticated IPsec bypass
# State: Enabled
# Supported on: At least Windows XP Professional with SP2
$path = 'HKLM:\SOFTWARE\Policies\Microsoft\Windows\IPSec\ICFv4'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'BypassFirewall' -Value '' -Type StringIntune XML
No direct Policy CSP / OMA-URI mapping for this policy. Use the Intune Remediation tab, or ingest the ADMX in Intune.Intune Remediation
# === Detection script ===
# Exported from gporais.com
# Policy: Windows Defender Firewall: Allow authenticated IPsec bypass
# State: Enabled
# Supported on: At least Windows XP Professional with SP2
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
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\SOFTWARE\Policies\Microsoft\Windows\IPSec\ICFv4' -Name 'BypassFirewall' -Expected '' -Kind String)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Windows Defender Firewall: Allow authenticated IPsec bypass
# State: Enabled
# Supported on: At least Windows XP Professional with SP2
$path = 'HKLM:\SOFTWARE\Policies\Microsoft\Windows\IPSec\ICFv4'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'BypassFirewall' -Value '' -Type StringSCCM scripts
# Exported from gporais.com
# Policy: Windows Defender Firewall: Allow authenticated IPsec bypass
# State: Enabled
# Supported on: At least Windows XP Professional with SP2
# 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: Windows Defender Firewall: Allow authenticated IPsec bypass
# State: Enabled
# Supported on: At least Windows XP Professional with SP2
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
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\SOFTWARE\Policies\Microsoft\Windows\IPSec\ICFv4' -Name 'BypassFirewall' -Expected '' -Kind String)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Windows Defender Firewall: Allow authenticated IPsec bypass
# State: Enabled
# Supported on: At least Windows XP Professional with SP2
$path = 'HKLM:\SOFTWARE\Policies\Microsoft\Windows\IPSec\ICFv4'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'BypassFirewall' -Value '' -Type StringBuilding a multi-setting collection? Add this setting and generate combined .reg / PowerShell / GPO scripts.