Forward Google DNS to Unlocator
Some devices like the Chromecast Gen 3 and Ultra have Google DNS hardcoded on the device. While Gen 1 and 2 will work if you block Google DNS on your router this is not the case with Gen 3 and Ultra. They will simply stop working.
So instead you need to forward DNS requests meant for Google DNS to be forwarded to Unlocator DNS.
This requires a bit of an advanced setup and not all routers have support for this. Open Source router software like Asuswrt, DD-WRT, Tomato, OpenWrt and Pfense have the ability to make such configurations. As do commercial routers like Unifi.
This is advanced configurations. We are not able to provide support for such configurations. The guide is provided as is. Please make sure you are comfortable making such changes to your router before proceeding.
In the below example my Chromecast has the IP 192.168.1.222. Please exchange this IP with the IP of the device you are forcing to forward to Unlocator. Make sure your device has a static IP to make it stick.
sudo iptables -t nat -A PREROUTING -s 192.168.1.222 -d 8.8.8.8 -j DNAT --to-destination 185.37.37.37 sudo iptables -t nat -A PREROUTING -s 192.168.1.222 -d 8.8.4.4 -j DNAT --to-destination 185.37.37.37