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 domain you want to resolve.
- Pick the record type: A, AAAA, CNAME, MX, TXT, or NS.
- Add your assertions on resolution time and record values.
- Optionally set a degraded threshold in milliseconds, so resolution that succeeds but is slow is reported as degraded rather than fully up.
- Pick your locations, alert channels, and frequency, then save.
Assertions on DNS Records
Assertions validate both speed and content. You can assert on the resolution time, and on the record values returned: for example, an A record must equal your expected IPs, or a TXT record must contain a given value. If an answer does not match, the check fails, so an unauthorized or accidental DNS change never goes unnoticed.
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.