First of all you need some always on device in your network to run this server on as DNS resolving will stop working if this server is down.

Both PiHole and Adguard Home have great Docker images you can use. I suggest using Docker to install your DNS blocker to make the process as simple as possible. How to install Adguard Home or PiHole with Docker As you have this local instance now cached requests can be even faster than before now and you avoid all the unnecessary traffic for ads. Everything else is passed on to a (configurable set of) external DNS server. To the client it looks like the server is just not reachable. If such content is found no address is returned. You basically run your own local DNS server that checks all requests for known spam/ads/unwanted content. This is where DNS based ad blocking steps in. Usually all devices in your network ask your router for a DNS server which will point them at the one chosen by your internet service provider. A DNS server is used to resolve this name to the actual address. If you open a website you are usually using a DNS name (like ) to avoid having to remember the actual IP address. To circumvent that problem you can utilize something else you (should) still own: your network infrastructure, or more precisely your router. On your (unrooted) smartphone this becomes a much harder problem, on other devices like smart speakers you have no control at all. On your desktop PC you can use some great browser plugins (like ublock Origin for Chrome in my case) to get rid of ads. They also waste a lot of bandwidth and can even be a potential security risk. While ads on the Internet can be a good thing when well used (they finance quite a lot of great and otherwise free services) they can also be very annoying and make the web nearly unusable in some cases. Is it worth the trouble? Why do you need ad blockers?

Adguarddns