I’ve been using adguards free DNS to eliminate adds and recently switched to Mullvads add free DNS. Mullvad lets through a few ads adguad catches but stops many other things. Since Netguard has 2 slots for DNS, I put them both. Is that a problem, or do I have the best of both worlds?
This depends on your OS. Many do it this way, but some (I think Windows is included here) periodically check and use the “fastest” one. I run 2 local DNS, and my windows devices tend to represent about 99% of the the queries showing up on the second DNS (which sees much lower traffic overall).
I have no idea what happens when you have 2 different blocklists though - it feels like you could open yourself up to a scenario where you only get content blocked if it’s blocked on BOTH lists, which would be the worst of both worlds in a sense.
Usually your OS will just send dns requests to both servers at once and just accept whichever responds first. UDP isnt very smart.