DNS checks
Create a DNS check for the record name you want to observe, such as
example.com or _dmarc.example.com. Use an ASCII DNS name without a scheme
or path. Names are lowercased and a final dot is removed.
| Option | Meaning and constraints |
|---|---|
| Record type | A, AAAA, CNAME, MX, TXT, NS or CAA |
| Match mode | Resolves, exact or includes |
| Expected records | One per line in the UI; required for exact/includes; at most 100 records of at most 4096 bytes each |
| Interval | Plan-constrained positive seconds |
| Resolvers required for healthy | Blank means all three; otherwise 1-3 |
| Resolvers required to avoid failing | 1-3; default two; must not exceed the healthy requirement |
| Notification groups | Existing account groups |
The three resolvers are Cloudflare (1.1.1.1), Google (8.8.8.8) and
Quad9 (9.9.9.9). They are created automatically; this is not a configurable
list of private DNS servers.
Matching
Section titled “Matching”Resolves requires a nonempty answer, without comparing expected values. Exact requires the complete normalized answer set to equal the expected set. Includes allows additional records but requires every expected record.
For newly created records without an explicit mode, A/AAAA/TXT use includes; other record types use exact. Review the selection shown by the form rather than assuming one mode applies to every type.
Use the form’s current-answer preview to populate expectations, then review them before saving. A preview captures existing answers, not the desired future state. Addresses are normalized; DNS-name values are case-insensitive and trailing dots are removed. MX values include priority; TXT values preserve their content. Do not use includes to match a substring inside a TXT record.
| Type | Example expected record | Normalization / constraint |
|---|---|---|
| A | 203.0.113.10 |
IPv4 address, no CIDR suffix |
| AAAA | 2001:db8::10 |
IPv6 address, no CIDR suffix |
| CNAME / NS | target.example.com |
ASCII name; lowercased, final dot removed |
| MX | 10 mail.example.com |
Priority 0-65535 plus hostname; null MX 0 . is supported |
| TXT | v=spf1 -all |
Nonempty literal text; content is preserved |
| CAA | 0 issue "ca.example" |
Flags 0-255, alphanumeric tag and value; tag lowercased |
Duplicate normalized values are removed and ordering is normalized. The addresses above are documentation examples, not live resolver answers.
Changes and propagation
Section titled “Changes and propagation”When you edit only expected records, prior expected answers can temporarily count as lagging while caches expire. The lag window uses observed TTLs, bounded between five minutes and 48 hours. Lagging resolvers count as healthy. Changing hostname, type or match mode resets the target instead of reusing old-answer tolerance.
Inspect answers, TTL and errors by resolver. A failed answer may be a lookup error, a genuine mismatch or an infrastructure-suspect result; these are not interchangeable. See DNS troubleshooting.