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.


Comments (2)

  1. Glad that it did help. Thanks!

  2. Anonymous says:

    thanks for this, was worried about this error