Answer
GFI WebMonitor Standalone Proxy Version can be chained with Microsoft TMG with the following authentication related limitations:
- If GFI WebMonitor Standalone Proxy Version is chained to Microsoft TMG Server and Integrated authentication is being used to authenticate users to the GFI WebMonitor proxy, the authenticated session will only be visible by GFI WebMonitor
- When the HTTP session is forwarded to Microsoft TMG server, the connection information does not include the authentication information submitted to GFI WebMonitor and will only appear to be originating from the GFI WebMonitor server. In this scenario, all user-based firewall policies created on Microsoft TMG server does not work since all connections only contain the IP address of the GFI WebMonitor server. New policies need to be created using the IP of the GFI WebMonitor to be applied.