As homes fill with Internet of Things (IoT) devices—from smart TVs to internet-connected appliances—the amount of localized telemetry data being harvested by advertising networks is staggering. Installing ad-blocker extensions on a web browser protects the PC, but it leaves every other network device exposed. The solution is Pi-hole, a powerful open-source application that acts as a DNS sinkhole for your entire local network.

How DNS Sinkholing Blocks Telemetry

Pi-hole replaces your standard router DNS server (usually provided by your ISP). When any device on your Wi-Fi network—whether it is a smartphone, a smart fridge, or a laptop—attempts to connect to the internet, Pi-hole cross-references the request against massive open-source blocklists containing millions of known malicious and advertising domains.

If a smart TV attempts to ping a known telemetry server to log your viewing habits, Pi-hole drops the DNS request entirely into a "sinkhole." The TV believes the tracking server is offline, saving bandwidth and stopping data harvesting at the network perimeter. However, Pi-hole only protects you while connected to your home router. When your mobile devices disconnect and switch to 5G cellular networks, the Pi-hole protection vanishes.