Resolution, propagation and domain expiry — a domain that stops resolving is an invisible outage until someone looks.
A, AAAA, CNAME, MX, TXT — the domain or subdomain to watch.
Resolver and check interval, just like a regular HTTP check.
The moment resolution fails or a record changes unexpectedly.
A, AAAA, CNAME, MX, TXT — watch whichever record type matters for your domain.
Alerted before the deadline — no more outages from a domain that wasn't renewed in time.
A resolution failing from a single region isn't necessarily a real DNS outage.