This is the second of two parts. Read Part 1:
Monitoring DNS is not simply a matter of checking whether a record resolves. A comprehensive approach follows four key principles:
- Test from multiple networks and regions to avoid blind spots.
- Validate both correctness and speed, since slow answers can harm user flows even when technically valid.
- Measure continuously, not periodically, because many issues manifest as short-lived or regionalized incidents.
- Compare control plane changes to real-world propagation patterns to ensure updates are…
