Yes! This is easy to do on OpenBSD as well, though it's called "redirect" instead of "DNAT":
pass in quick on $int_if inet proto udp to any port 53 rdr-to $dns_server port 53
pass in quick on $int_if inet proto tcp to any port 53 rdr-to $dns_server port 53Overall, it's just easier not to connect "smart" devices to the Internet at all. I prefer to use a Linux HTPC instead of a smart TV for example. It is completely under my control and I am not restricted to apps approved by Apple or Google, asked to log into anything or to accept ever-changing terms and conditions.