How to use this tool
Reverse DNS Consistency Check: interpretation and next steps
Reverse DNS Consistency Check verifies whether reverse-DNS delegations cover the routed and registered space of a prefix or ASN. It is a practical post-allocation check for IPv4 and IPv6 operators.
What this check answers
A complete delegation result means RIPEstat found reverse-DNS delegation coverage for the returned prefix space. It does not validate the individual PTR records your hosts return.
Workflow
- Enter a CIDR prefix, or an ASN for broader coverage.
- Check whether each returned block reports Complete or Incomplete delegation coverage.
- Use the domain list to inspect missing or unexpected reverse zones.
Example and limits
For an IPv4 /21, complete coverage normally means each constituent /24 reverse zone is delegated or represented as expected.
- Delegation coverage is not the same as having a PTR for every host.
- Large ASN queries can return many prefixes; start with the affected CIDR.
Frequently asked questions
Does Complete mean every server has PTR?
No. It checks delegation consistency, not per-host PTR content.
Why check reverse DNS after getting IPv6?
Mail, operations, and service identification commonly rely on correctly managed reverse DNS.
Can this change delegation?
No. It is read-only.