Help: Block unicast responses to a computer's outgoing multicast traffic

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

To block unicast responses to a computer's outgoing multicast traffic

Type the following at the command prompt, and press ENTER:

netsh firewall set multicastbroadcastresponse disable

Notes

Windows Firewall is not included in the original release of the Windows Server 2003 operating systems.
You can also use Group Policy settings to perform this procedure and configure other Windows Firewall settings.
You can configure Windows Firewall settings in the standard profile or the domain profile. The domain profile is used when a computer is connected to a network in which the computer's domain account resides. The standard profile is used when a computer is connected to a network in which the computer's domain account does not reside, such as a public network or the Internet. Make sure Windows Firewall is using the correct profile when you perform this procedure.
You cannot use Windows Firewall in Control Panel to perform this procedure.
If you perform this procedure, and this computer sends multicast or broadcast messages to other computers, Windows Firewall blocks the unicast responses sent by those other computers.
By default, when this computer sends a multicast or broadcast message to other computers, Windows Firewall waits as long as three seconds for unicast responses from the other computers and then blocks all later responses.