Firewall Swap & Windows Telemetry Data

I recently switched over from Sophos UTM to Untangle NG for my personal use firewall at home. During the process I basically had to rebuild all of my firewall rules and general network policy configurations. This allowed to me “start fresh” as my previous configuration had gotten quite bloated and complicated over time.

It’s clear that Microsoft has no intentions of telling us what exactly is sent in this telemetry data, how long it’s stored, and why when it’s disabled it continues to send data. Not to mention which obvious third parties have access to the data. For this reason, part of the new network policies I wanted to include was blocking telemetry data from getting sent back to the Microsoft mother-ship.

This is accomplished with Web Filtering and works for both HTTP and HTTPS. I also use a second layer of protection by using OpenDNS domain blocking. That means that if for some reason a request makes it past the web filtering, it will be blocked at the DNS level.

One thing I quickly noticed after blocking these domains was how much they were being used. From the web filtering and OpenDNS filtering combined it adds up to literally tens of thousands of blocked requests and is in the top 10 of my overall DNS requests.

000374_2016-09-12-11_31 000373_2016-09-12-11_16

I don’t get it. What and why, especially when I have telemetry set to the lowest collection setting? I cannot imagine the amount and type of data that is sent when it’s set to full! After seeing how much data is collected and how often it attempts to send on low, it gives me reassurance that yes – these domains need to be blocked. 

The full list of blocked domains is:

Karl has been involved in the virtualization, server, web development and web hosting industry for over 15 years. In his current role at a managed service provider, he is focused on cloud-based solutions for enterprise clients. His diverse background of sales, management, and architectural/technical expertise bring a unique perspective to the virtualization practice.


  1. sml156

    Have you considered that since you are blocking these domains that instead of Windows trying to connect once a day to say hello I’m here, it will then try to connect every 1 second

    • Do you have a source for this information? A quick capture on Wireshark shows this is false.

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