Originally Posted by
gfunkdave
I recently discovered that my Samsung TV ignores the DNS server specified by my DHCP server and just uses 8.8.8.8. No wonder I still see ads on it. I had to set a NAT rule to override outbound port 53 and redirect it back to NextDNS.
You'll probably find that if you simply block it from getting to 8.8.8.8 and 8.8.4.4, or just block all outgoing port 53 except to where you want DNS to go, then it'll start working as you want. I've seen devices do this before - they try 8.8.8.8 or similar, but if they can't get to there then they'll use what DHCP has told them to use.