Policy
Windows Defender Firewall: Prohibit unicast response to multicast or broadcast requests
Microsoft Windows
Policy overview
Key metadata and intent for this policy.
Supported OS tags: Windows10, Windows10RT, Windows11, Windows7, Windows8, Windows81, WindowsRT, WindowsRT81, WindowsServer2008, WindowsServer2012, WindowsServer2012R2, WindowsServer2016, WindowsVista, WindowsXP
Prevents this computer from receiving unicast responses to its outgoing multicast or broadcast messages. If you enable this policy setting, and this computer sends multicast or broadcast messages to other computers, Windows Defender Firewall blocks the unicast responses sent by those other computers. If you disable or do not configure this policy setting, and this computer sends a multicast or broadcast message to other computers, Windows Defender Firewall waits as long as three seconds for unicast responses from the other computers and then blocks all later responses. Note: This policy setting has no effect if the unicast message is a response to a Dynamic Host Configuration Protocol (DHCP) broadcast message sent by this computer. Windows Defender Firewall always permits those DHCP unicast responses. However, this policy setting can interfere with the NetBIOS messages that detect name conflicts.
Registry values
How enabled and disabled states update the registry.
| Scope | Registry location | Type | Enabled value | Disabled value | Copy |
|---|---|---|---|---|---|
| Computer | Path SOFTWARE\Policies\Microsoft\WindowsFirewall\DomainProfile Value name DisableUnicastResponsesToMulticastBroadcast | REG_DWORD | HKLM 1 | HKLM 0 |
Policy elements
Inputs and configuration options exposed by this policy.
This policy has no additional user input fields.