DNS
Check that a name resolves to the expected records.
Pick a record type (A, AAAA, CNAME, MX, NS or TXT) and, optionally,
a resolver (1.1.1.1 or ip:port; the system resolver otherwise).
Expected values must all be in the answers, compared without case or a
trailing dot, e.g. 93.184.215.14 or 10 mail.example.com. Without expected
values, the monitor is up whenever the name resolves.
Answers aren't cached between checks.