Remove the CNAME that leads to a dead target

Why it matters

A CNAME in your zone points at a name that does not resolve any more, either because it no longer exists or because the servers behind it are gone, so the subdomain is broken. Nobody else can claim the target, so this is housekeeping rather than a takeover risk, but a stale record is clutter that breaks visitors and mail.

The fix

1. Find the CNAME in the zone, using the name from the finding, and decide whether the subdomain is still wanted.
2. If not, delete the record. If it is, point it at the correct current target (ask the provider that used to host it).
3. Check for references to the subdomain in your site, email links and monitoring, and update them.

# replace sub with the subdomain named in the finding
dig CNAME sub.example.com +short
dig sub.example.com

The examples use example.com. Replace it with your own domain.

Read the documentation ↗(opens in a new tab)

Related

• Reported by the Dangling CNAMEs check
• Delete the CNAME that points at an unregistered domain
• Remove or reclaim the CNAME to a deprovisioned service
• Move the CNAME to an internal name out of public DNS
• Delete the CNAME that points at a name that does not exist
• Fix the wildcard CNAME that points at a missing name