Noticing when something changes.
WHY
An unexpected nameserver or record change is a serious signal: a compromised registrar account, or an unauthorised transfer.
It may also be a colleague or a service making a change nobody told you about.
WHAT TO MONITOR
Nameservers The main A record MX records Whether the domain still resolves at all
WHAT SERVICES EXIST
Several monitoring services check DNS records and alert on changes.
Some uptime monitors include this.
THE SIMPLE VERSION
Check annually as part of a health review, and after any incident.
For a business whose domain matters, an alerting service is a small cost.
WHAT AN UNEXPECTED CHANGE MEANS
Investigate immediately. Do not assume it was legitimate.
Check who has access to the registrar and the DNS provider.
WHAT TO DO IF IT WAS NOT YOU
Change credentials immediately Contact the registrar Restore the correct records Review access
DOMAIN EXPIRY
Monitor that too. It is the most common cause of a domain suddenly failing, and it is entirely preventable.
