I was making a quick check, and yes, the DoH situation is a bit more dicey. From how I see it, the best way to make this work is to, at the firewall level, either block as much as possible any requests that look like DoH (and hope whatever was using that falls back to regular DNS calls) or setup a local DoH server to resolve those queries (although I am not sure if it is possible to fully redirect those). In that sense, pihole can’t really do much against DoH on its own
EDIT: decided to look a bit further on the router level, and for pfsense at least this is one way to do this recipe for DNS block and redirect
Hm… I am not familiar with that device myself, and since I use opnsense for a while I forget most people do not use routers outside of the provided one.
But in a theoretical sense, this firewall rule should look something like this:
- origin of traffic is any IP that goes into port 53
- outgoing traffic has to go to pi hole on port 53
Pi hole is an amazing tool and gives a lot of insight on what is being queried and blocked against the block lists. Also, makes completely transparent on the entire network to have nasty things blocked. One thing I will mention to make the setup better: make sure on the firewall level you can have a rule that makes every request for a DNS to go through pi hole. Some devices will use a hard coded DNS instead of respecting the one on the network
I am not sure if by any chance they do the extra mile to check on that. However, as a rule of thumb you should try to keep private stuff away from work stuff, meaning, at work maybe is not the best idea to boast about your reddit profile where you happen to follow some nsfw stuff (or other stuff that can be considered offensive and/or can lead to controversy). I would imagine they try to check things such as accounts attached to an email or phone number (for instance). If a set of aliases were used for this (or different info) from your work email phone etc., you should be able to keep it separate.