This error indicates a DNS resolution failure preventing access to the requested domain.
- A web request was sent to a Cloudflare IP address ↗︎ for a non-existent Cloudflare domain.
- An external domain that is not on using Cloudflare has a CNAME record to a domain active on Cloudflare
- The target of the DNS CNAME record does not resolve.
- A CNAME record in your Cloudflare DNS app requires resolution via a DNS provider that is currently offline.
A non-Cloudflare domain cannot CNAME to a Cloudflare domain, unless the non-Cloudflare domain is added to a Cloudflare account.
Attempting to directly access DNS records used for Cloudflare CNAME setups also causes error 1001. For example, www.example.com.cdn.cloudflare.net.