Richard Hicks' Forefront TMG Blog

As I recently mentioned, Microsoft has discontinued and will be terminating their Microsoft Reputation Services (MRS) cloud URL categorization service on or shortly after December 31, 2015. Today, Microsoft released additional information vital to TMG administrators everywhere who are still relying on this service for URL filtering. Specifically, what happens with TMG once Microsoft officially turns off MRS and it is no longer available?

Bad things.

First, any firewall rules that rely on URL categorization to allow traffic will fail closed. That is, they will block all traffic. Second, any rules using URL categorization to deny traffic will fail open and allow that traffic instead. Finally, there is potential performance degradation that may occur with TMG after the service is disabled by Microsoft.

What to do?

First, update any TMG firewall rules that use URL Categories or URL Category Sets. You can replace them with Domain Name Sets or URL Sets, if desired. Next, disable the use of URL filtering in TMG by opening the TMG management console, right-clicking Web Access Policy and choosing Configure and then URL Filtering. Uncheck the box next to Enable URL Filtering and then click Ok.

Finally, consider a replacement solution for TMG’s URL filtering. There are a number of solutions available, both on-premises and cloud-based, that are capable replacements. The Zscaler solution is highly effective, and if you’re looking for a low-buck alternative, consider something like OpenDNS. There are many more, I’m sure.

Good luck!