Privacy and telemetry

Blocking your TV's ads at the router

· 2 min read

Illustration. Decorative: the diagrams in the text carry the detail.

Everything else on this site requires your television to be an Android. This does not. Filtering at the network level works with any connected device, including Samsungs on Tizen and LGs on webOS.

The idea

When the television wants to send telemetry or load an advert, it first asks DNS for that server's address. If DNS answers that it does not exist, the connection is never made.

You are not modifying the television. You are deciding what your own network resolves.

The three options, least to most work

1. A public DNS with filtering. Change the router's DNS and you are done. Free, five minutes.

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Known options: AdGuard DNS, NextDNS, Mullvad DNS. NextDNS also shows you what each device in your house is asking for, which is revealing in itself.

2. Pi-hole or AdGuard Home. Your own DNS server on a Raspberry Pi or any machine you leave running. More work, total control, and detailed per-device statistics.

3. Rules on the router, if yours allows blocking domains directly.

Working out what to block

With Pi-hole or NextDNS, the tool itself shows you the queries. Filter by the television's IP and you will see its real traffic. It is the most instructive exercise you can do: plenty of people discover this way how many queries an hour their television makes while switched off.

An important caution

Blocking too much has side effects:

The practical recommendation: start with a conservative block list, use the television for a few days, and refine.

The best thing about this method

It is completely reversible and touches nothing on the device. If something breaks, you remove the filter and everything is back instantly. That makes it a good first measure before getting into ADB.

Everything here applies to a device you own, and every removal is reversible. The limits of this project: What we do and do not do