# DNS Monitor

- Import the `DnsMonitor` construct from `checkly/constructs`.
- Reference [the docs for DNS monitors](https://www.checklyhq.com/docs/constructs/dns-monitor/) before generating any code.
- When adding `assertions`, always use `DnsAssertionBuilder` class.
- **Plan-gated properties:** `retryStrategy`, `runParallel`, and higher frequencies are not available on all plans. Check entitlements matching `UPTIME_CHECKS_*` before using these. Omit any property whose entitlement is disabled. See `npx checkly skills manage` for details.

**Reference:** https://www.checklyhq.com/docs/constructs/dns-monitor/

```typescript
import { AlertEscalationBuilder, DnsAssertionBuilder, DnsMonitor, Frequency, RetryStrategyBuilder } from 'checkly/constructs'

new DnsMonitor('example-dns-monitor', {
  name: 'Example DNS Monitor',
  degradedResponseTime: 500,
  maxResponseTime: 1000,
  activated: true,
  locations: [
    'eu-central-1',
    'eu-north-1',
  ],
  frequency: Frequency.EVERY_10M,
  alertEscalationPolicy: AlertEscalationBuilder.runBasedEscalation(1, {
    amount: 0,
    interval: 5,
  }, {
    enabled: false,
    percentage: 10,
  }),
  retryStrategy: RetryStrategyBuilder.noRetries(),
  request: {
    recordType: 'AAAA',
    query: 'INSERT_HOSTNAME',
    assertions: [
      DnsAssertionBuilder.responseCode().equals('NOERROR'),
    ],
  },
})
```