When DNS is wrong, everything is down while every server is fine. Monitoring DNS is cheap insurance.
What to monitor
- A and AAAA records of your main hosts against the expected IPs
- MX records, so email keeps arriving
- NS records, to detect a hijacked or expired domain
- TXT records with SPF and DKIM
- Resolver latency
Alert on change, not only on failure
A DNS monitor with an expected value alerts when the answer changes, which is exactly what a hijack or a botched migration looks like.
Check now
Use the free DNS lookup tool to see your current records from an EU resolver.