“You can’t force your TV to actually use that DNS” – turns out you actually can

Hey, this is a reaction to this video: https://www.youtube.com/watch?v=oeqUHEp4sYM
Where Linus said, you can only tell TVs to use your DNS servers, and some TVs might ignore the DHCP setting. There's a quite easy way to enforce the use of your DNS with proper router configuration:

1. Grab all traffic on port 53 – this port is reserved for DNS traffic
2. Check if the source IP is not your DNS server (because you still need a working upstream)
3. Forward all traffic that matched these rules to your DNS servers
4. On your DNS, block domains for DNS over HTTPS and DNS over TLS

This work, because the DNS protocol doesn't mind if the reply came from a different IP than it was sent to. I'm including a screenshot from my MikroTik router with this NAT rule. You have to set two rules, one for UDP and one for TCP.

https://preview.redd.it/dhsitfmlkylh1.png?width=1322&format=png&auto=webp&s=7366addca1c7872a87ea695b283ccfcbb34a5d5d