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A comment on It’s Still Stupidly, Difficult to Buy a ‘Dumb’ TV. Parent comment

Re:It’s Still Stupidly, Difficult to Buy a ‘Dumb’ TV by mschuster91 on Friday April 15, 2022 @08:57AM (#31039663)
> Blocking the MAC address from making connections outright seems like a more sensible way to prevent surveillance.

That won't protect against DNS data exfiltration. Extremely low-bandwidth, but works in a lot of cases - people have even written proxy servers to get slow but working Internet on public hotspots that normally require login.

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Re:It’s Still Stupidly, Difficult to Buy a ‘Dumb’ TV by ezfe on Friday April 15, 2022 @09:50AM (#31040212)
How does that work if you block the internet at the router level?
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Re:It’s Still Stupidly, Difficult to Buy a ‘Dumb’ TV by mschuster91 on Friday April 15, 2022 @10:58AM (#31040974)
Simple: most router firewalls only block traffic that has source:<IP of device> and destination:<anything in the Internet>, but traffic from source:<IP of device> to destination:<IP of router, IP range of home network> will be allowed.

That is enough for the device to emit a DNS query like "pbs.12345.metricservice.example.com" to notfiy some tracking service that the device with serial 12345 just switched to a channel labeled "PBS". The router will resolve that name record at the DNS server for metricservice.example.com, which gets the request and logs it away.

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Re:It’s Still Stupidly, Difficult to Buy a ‘Dumb’ TV by chrisjc on Friday April 15, 2022 @11:56AM (#31041678)
Are you suggesting that devices connected to a network that has blocked their MAC can still make DNS requests?
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Re:It’s Still Stupidly, Difficult to Buy a ‘Dumb’ TV by mschuster91 on Friday April 15, 2022 @09:08PM (#31048043)
How many consumer routers go that length? For most of these, as long as they are on the network, they can communicate over DNS, using the router as "middleman".
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