Everything else is fine until the name stops resolving
A DNS monitor asks the resolver for your hostname on a schedule and alerts you when nothing comes back. Expired domains, zone migrations gone wrong, a deleted record: the outage nobody sees on the server.
Free for one monitor. No card needed.
Why DNS deserves its own monitor
When DNS breaks, your servers keep running and every dashboard stays green. Customers, meanwhile, get a browser error that looks like your site was deleted. The usual causes are dull: a domain renewal that bounced, a record removed during a migration, a registrar change that did not copy the zone. All of them are invisible from inside your infrastructure.
A DNS monitor looks from the outside. Every interval it resolves the name, records the answers and the time it took, and treats a name with no A, AAAA or CNAME records as down. Because the check is separate from your HTTPS monitor, you can tell at a glance whether the site is unreachable or simply unnamed.
Every name customers type
The apex, www, the API host, the shop subdomain, and the underscore names your certificate renewal depends on. Each monitor resolves its name against a resolver with a 10 second timeout and two tries, so one dropped packet is not a failure.
- A, AAAA and CNAME answers all count, so IPv6-only and aliased names work
- NXDOMAIN, no records, and resolver errors are reported as different failures
- Resolution time is kept per check, so a slow resolver shows before a dead one
The 2 am zone migration
Link the monitor to a status page component and give it a rule. When a name stops resolving for as many checks in a row as you set, the component changes, an incident opens, and subscribers hear about it while you are still finding the runbook.
- Alerts to your team on the channel they actually read
- Incidents use your template, so the wording is right even when the timing is not
- Recovery moves the incident to Monitoring; you write the last word
Setting one up
Enter a hostname
Not an IP address; there is nothing to resolve. Underscore names such as _dmarc are fine.
Choose an interval
Every minute is plenty. DNS changes propagate in minutes, not seconds.
Link a component
Point the monitor at the component that name serves, and choose what a failure should do.
The other checks
DNS monitoring questions
Find out before the domain does.
One monitor and a status page, free. No card needed.