I’m responsible for a bunch of IoT hardware, and every firmware spec I write includes a note on not using the DNS servers provided via DHCP. While sure there are companies explicitly doing this to avoid filtering, at least in my case it’s because a significant proportion of DHCP servers are configured to send DNS to your ISP, and ISP provided DNS is almost universally terrible. They’ll ignore TTLs, rewrite NXDOMAIN r…
[1]: https://github.com/bambenek/block-doh
[2]: https://github.com/Sekhan/TheGreatWall
Edit: I am mostly curious to see what devices/applications it will break.