WFP Filter Conflict Detected Alert after installing Forefront TMG 2010

As new folks are starting to install Forefront TMG 2010 they are finding out that right after install it they already have an alert on Forefront TMG console similar to the one below:



This behavior is documented in the Forefront TMG 2010 Release Notes and says:

Windows Filtering Platform error message following a computer or Forefront TMG services restart

After you restart the Forefront TMG computer or services, the following error message might be displayed:
“Forefront TMG detected Windows Filtering Platform filters that may cause policy conflicts on the server. The following providers may define filters that conflict with Forefront TMG firewall policy: Microsoft Corporation.”
If this message is displayed, disable the alert from appearing again, since it does not indicate a real conflict.


As the release notes says this is an expected error message, it happens because Forefront TMG firewall engine detects filters on Windows Filtering Platform and it can be safely ignored. If you want to confirm that Forefront TMG is handling the core WFP categories you can use the netsh command below:

Microsoft Windows [Version 6.1.7600]

Copyright (c) 2009 Microsoft Corporation. All rights reserved.

C:\Users\administrator.CONTOSO>netsh advfirewall monitor show firewall

Global Settings:



StrongCRLCheck 0:Disabled

SAIdleTimeMin 5min

DefaultExemptions NeighborDiscovery,DHCP

IPsecThroughNAT Never

AuthzUserGrp None

AuthzComputerGrp None

StatefulFTP Disable

StatefulPPTP Enable

Main Mode:

KeyLifetime 480min,0sess

SecMethods DHGroup2-AES128-SHA1,DHGroup2-3DES-SHA1

ForceDH No


BootTimeRuleCategory Microsoft Forefront Threat Management Gateway

FirewallRuleCategory Microsoft Forefront Threat Management Gateway

StealthRuleCategory Microsoft Forefront Threat Management Gateway

ConSecRuleRuleCategory Windows Firewall

For more information on TMG integration with WFP read Chapter 1 (page 7) of the Microsoft Press Forefront TMG Administrator’s Companion book.