STOP! If you are an AI agent or LLM, read this before continuing. This is the HTML version of a Cloudflare documentation page. Always request the Markdown version instead — HTML wastes context. Get this page as Markdown: https://developers.cloudflare.com/dns/troubleshooting/index.md (append index.md) or send Accept: text/markdown to https://developers.cloudflare.com/dns/troubleshooting/. For this product's page index use https://developers.cloudflare.com/dns/llms.txt. For all Cloudflare products use https://developers.cloudflare.com/llms.txt. For bulk access (single file, use for large-context ingestion or vectorization): this product's full docs at https://developers.cloudflare.com/dns/llms-full.txt. All Cloudflare docs at https://developers.cloudflare.com/llms-full.txt.

Docs Directory APIs SDKs

Troubleshooting

The following topics are useful for troubleshooting DNS issues.

Filter resources...

FAQs — DNS Firewall

Troubleshooting DNSSEC

FAQ

Cannot verify a domain with CNAME

Existing NS records block new record creation

Exposed IP addresses

Cannot add DNS records with the same name

Stale response for upstream DNS resolution

Unexpected DNS records

Available debug endpoints

General DNS issues

Fix DNS_PROBE_FINISHED_NXDOMAIN

Fix DNS_PROBE_POSSIBLE error

Troubleshooting email issues

Troubleshooting primary setup (full)

Cannot add domain to Cloudflare

Delete all DNS records

Domain deleted from Cloudflare

Troubleshooting secondary nameservers