193-Windows Firewall: Allow ICMP exceptions

Computer/User Node :

   MACHINE

Policy Path :

   Administrative Templates\Network\Network Connections\Windows Firewall\Domain Profile

Supported on :

   At least Microsoft Windows XP Professional with SP2

Help/Explain Text :

   Defines the set of Internet Control Message Protocol (ICMP) message types that Windows Firewall allows. Utilities can use ICMP messages to determine the status of other computers. For example, Ping uses the echo request message. If you do not enable the Allow inbound echo request message type, Windows Firewall blocks echo request messages sent by Ping running on other computers, but it does not block outbound echo request messages sent by Ping running on this computer. If you enable this policy setting, you must specify which ICMP message types Windows Firewall allows this computer to send or receive. If you disable this policy setting, Windows Firewall blocks all unsolicited incoming ICMP message types and the listed outgoing ICMP message types. As a result, utilities that use the blocked ICMP messages will not be able to send those messages to or from this computer. Administrators cannot use the Windows Firewall component in Control Panel to enable any message types. If you enable this policy setting and allow certain message types, then later disable this policy setting, Windows Firewall deletes the list of message types that you had enabled. If you do not configure this policy setting, Windows Firewall behaves as if you had disabled it, except that administrators can use the Windows Firewall component in Control Panel to enable or disable message types. Note: If any policy setting opens TCP port 445, Windows Firewall allows inbound echo requests, even if the Windows Firewall: Allow ICMP exceptions policy setting would block them. Policy settings that can open TCP port 445 include Windows Firewall: Allow file and printer sharing exception, Windows Firewall: Allow remote administration exception, and Windows Firewall: Define port exceptions. Note: Other Windows Firewall policy settings affect only incoming messages, but several of the options of the Windows Firewall: Allow ICMP exceptions policy setting affect outgoing communication.

Registry Settings :

  HKLM\SOFTWARE\Policies\Microsoft\WindowsFirewall\DomainProfile\IcmpSettings!AllowOutboundDestinationUnreachable, HKLM\SOFTWARE\Policies\Microsoft\WindowsFirewall\DomainProfile\IcmpSettings!AllowOutboundSourceQuench, HKLM\SOFTWARE\Policies\Microsoft\WindowsFirewall\DomainProfile\IcmpSettings!AllowRedirect, HKLM\SOFTWARE\Policies\Microsoft\WindowsFirewall\DomainProfile\IcmpSettings!AllowInboundEchoRequest, HKLM\SOFTWARE\Policies\Microsoft\WindowsFirewall\DomainProfile\IcmpSettings!AllowInboundRouterRequest, HKLM\SOFTWARE\Policies\Microsoft\WindowsFirewall\DomainProfile\IcmpSettings!AllowOutboundTimeExceeded, HKLM\SOFTWARE\Policies\Microsoft\WindowsFirewall\DomainProfile\IcmpSettings!AllowOutboundParameterProblem, HKLM\SOFTWARE\Policies\Microsoft\WindowsFirewall\DomainProfile\IcmpSettings!AllowInboundTimestampRequest, HKLM\SOFTWARE\Policies\Microsoft\WindowsFirewall\DomainProfile\IcmpSettings!AllowInboundMaskRequest, HKLM\SOFTWARE\Policies\Microsoft\WindowsFirewall\DomainProfile\IcmpSettings!AllowOutboundPacketTooBig