Disable DNSSEC
DNS Security Extensions (DNSSEC) adds an extra layer of authentication to DNS, ensuring requests are not routed to a spoofed domain.
For additional background on DNSSEC, visit the Cloudflare Learning Center ↗.
If you are onboarding an existing domain to Cloudflare, make sure DNSSEC is disabled at your registrar (where you purchased your domain name). Otherwise, your domain will experience connectivity errors when you change your nameservers.
Provider-specific instructions
This is not an exhaustive list of how to update DS records in other providers, but the following links may be helpful:
Why you have to disable DNSSEC
When your domain has DNSSEC enabled ↗, your DNS provider digitally signs all your DNS records. This action prevents anyone else from issuing false DNS records on your behalf and redirecting traffic intended for your domain.
However, having a single set of signed records also prevents Cloudflare from issuing new DNS records on your behalf (which is part of using Cloudflare for your authoritative nameservers). So if you change your nameservers without disabling DNSSEC, DNSSEC will prevent Cloudflare's DNS records from resolving properly.