track network changes and reconfigure as validating stub / resolver automatically
There should be a module to track changes in the network and environment to detect when the resolver is in an:
- Environment that blocks DNS queries altogether (and revert to stub mode)
- Environment with DNSSEC-unaware resolver (do validation)
- Open environment (full recursive resolver)
This would make it as painless as possible for the end users with frequent network transitions (hotel wifi, workplace, home, ...)
Fallback to https://github.com/fcambus/rrda if the DNS is filtered/unreachable.