Fedora and fallback DNS servers

I remember using 4.2.2.2 in similar situations back in 2007.

Since then I switched to doing recursive DNS resolution on my laptop with a local unbound daemon, but that just introduced more issues. Networks where recursive resolving is too slow to work, ISPs that block outgoing DNS queries except to their own resolver, ISPs that strip DNSSEC results and so on.

Perhaps the right thing to do is to move the fallback DNS servers into the network configuration settings. Then when you have issues on a particular network you just reconfigure the corresponding network connection to choose one of the available public DNS servers. You could probably do better though; if systemd-resolved detects DNS server issues (an ISP known to sell your data, a country without privacy regulation, DNS servers that don't support DoT/DoH, broken resolution, stripping DNSSEC, etc) it can prompt the user in the GUI and give them the option to switch the configuration for the current network to one of the several different public resolvers, with information about their country of origin, countries of deployment, privacy policies etc.