DNS Monitors
What a DNS Monitor Is
A DNS Monitor resolves your domain on a schedule from LoadFocus cloud regions and checks the answers it gets back. It supports the common record types: A, AAAA, CNAME, MX, TXT, and NS. Each check measures the resolution time and validates the returned records against the assertions you define, so you catch unauthorized or accidental DNS changes as well as slow resolution.
DNS monitors are available on the free plan. They count toward the free monitor allowance and run at a 5-minute frequency on free, or 1-minute on paid plans.
When to Use It
- Detect hijacked or accidentally changed records: an A record that suddenly points somewhere else is caught on the next check.
- Verify propagation after a migration: confirm that new records are being served from every region before you decommission the old setup.
- Watch resolution latency: slow DNS adds delay to every request your users make.
- Confirm MX and TXT records for email and SPF: a lost or altered record can silently break mail delivery.
Create a DNS Monitor
- Open the New API Check page.
- Choose the DNS type.
- Enter the Hostname you want to resolve, for example
example.com. - Pick the Record type: A, AAAA, CNAME, MX, TXT, or NS.
- Optionally enter an Expected value and choose how to Match it: contains, equals, not contains, or not equals.
- Optionally set the Resolution timeout (ms) (1000 to 20000, default 5000) and a Degraded threshold (ms), so resolution that succeeds but is slow is reported as degraded rather than fully up.
- Pick your locations, alert channels, and frequency, then save.
Checking the Returned Records
The Expected value checks the content of the answer: for example, an A record must equal your expected IPs, or a TXT record must contain a given value. If the answer does not match, the check fails, so an unauthorized or accidental DNS change does not go unnoticed. Speed is covered by the Resolution timeout (the check fails if no answer arrives in time) and the Degraded threshold (slow but successful answers are reported as degraded). Checks use LoadFocus's own resolver, not a nameserver you choose.
Multi-Region Checks
Like other LoadFocus checks, a DNS monitor can run from multiple regions. Each region resolves your domain independently, which catches resolver-specific problems and regional propagation issues that a single-location check would miss.
For a broader look at why DNS deserves its own checks, see DNS monitoring. For the shared settings, frequency, locations, alert channels, activate/mute, see How to Create a New API Check. For port-level checks below the application layer, see TCP Port Monitors.
You can find all your checks on the API Monitors page.