Turn Off Smart Multi-Homed Name Resolution
Disables parallel DNS queries to multiple interfaces. Prevents DNS leakage.
- Policy path
- Computer Configuration > Administrative Templates > Network > DNS Client
- Supported on
- Windows 10, Windows 11, Windows Server 2016 and later
Disables parallel DNS queries to multiple interfaces. Prevents DNS leakage. Security baselines recommend setting it to Enabled.
Description
Turn Off Smart Multi-Homed Name Resolution is a Windows Group Policy setting located under Computer Configuration > Administrative Templates > Network > DNS Client. It applies to the Computer Configuration branch and is classified as a Warning-level policy in the Network category.
Disables parallel DNS queries to multiple interfaces. Prevents DNS leakage.
Microsoft sets the default value to Not configured while industry security baselines (CIS, NIST, DISA STIG) recommend Enabled.
Under the hood, this policy is enforced through the Windows registry at HKLM\Software\Policies\Microsoft\Windows NT\DNSClient using the value name DisableSmartNameResolution. Modifying the value directly through regedit.exe or PowerShell produces the same effect as configuring the GPO, but going through Group Policy is preferred so that the setting is centrally managed and survives reboots, image rebuilds, and policy refresh cycles.
In-depth explanation
This setting has a meaningful impact on the security posture or operational stability of the system. Leaving it at the Microsoft default is acceptable for standalone or low-risk environments, but most security baselines (CIS, NIST, DISA STIG) explicitly call for hardening it before the device is exposed to untrusted users or networks.
The policy is grouped under Network – DNS & Connections, which means it is typically applied through a domain-wide GPO linked at the OU level. In a multi-tenant MSP context, scope it through WMI filters or security group filtering rather than linking at the domain root, so that you can roll out progressively (pilot OU → wider rings → all production).
The setting takes effect after the next Group Policy refresh (gpupdate /force for immediate testing, or by default within ~90 minutes for workstations and ~5 minutes on domain controllers). For computer-side policies a reboot may be required; for user-side policies, a sign-off/sign-on cycle is enough.
Use cases
- Apply organization-wide hardening of network on all domain-joined Windows endpoints.
- Roll out a CIS Benchmark-aligned baseline targeting 'Turn Off Smart Multi-Homed Name Resolution' via a dedicated GPO.
- Reduce attack surface for accounts that handle privileged credentials or sensitive data.
- Standardize the configuration across multiple customer tenants for an MSP-managed fleet.
Security implications
Leaving this policy at default does not directly grant an attacker access, but it widens the blast radius once initial access is obtained – passwords are easier to guess, lockout doesn't fire, audit trails are incomplete, or lateral movement is quieter. Most regulators and cyber-insurance underwriters now expect this control to be in place at least at the recommended level.
How to configure
- Open Group Policy Management Console (
gpmc.msc) on a domain controller or a workstation with RSAT installed. - Create or edit a GPO linked to the OU containing the target computer configurations. We recommend a dedicated baseline GPO (e.g. SEC – Network) instead of editing Default Domain Policy.
- Navigate to
Computer Configuration > Administrative Templates > Network > DNS Client. - Open Turn Off Smart Multi-Homed Name Resolution and set it to
Enabled. - Click OK and close the editor.
- On the target endpoint, run
gpupdate /force(or wait for the next refresh cycle), then verify withrsop.mscorgpresult /h report.html.
Direct registry path: HKLM\Software\Policies\Microsoft\Windows NT\DNSClient\DisableSmartNameResolution. You can apply the same change with PowerShell:
New-Item -Path 'HKLM\Software\Policies\Microsoft\Windows NT\DNSClient' -Force | Out-Null
Set-ItemProperty -Path 'HKLM\Software\Policies\Microsoft\Windows NT\DNSClient' -Name 'DisableSmartNameResolution' -Value <value> -Type DWordRegistry mapping
HKLM\Software\Policies\Microsoft\Windows NT\DNSClientDisableSmartNameResolutionREG_DWORDNot configured
