DNS Resolver

IP ↔ Hostname

Enter either a public IP address or a domain. OCS Ping automatically chooses forward or reverse DNS lookup.

IP address→ PTR hostnameDomain→ A / AAAA addresses
LEARN

Forward DNS and reverse DNS are different checks

Forward DNS starts with a hostname and finds its published A or AAAA addresses. Reverse DNS starts with an IP address and queries its PTR record to find the hostname assigned to that address, when one exists.

The two directions do not have to match. OCS Ping can also compare a PTR hostname with its forward resolution to help you see whether the reverse name resolves back to the original address.

FAQ

Common questions

Who controls a PTR record?

The organization controlling the IP address block or its delegated reverse DNS zone normally manages PTR records.

Does every public IP have reverse DNS?

No. A public IP can work normally without a PTR record.

Should forward and reverse DNS always match?

Not always, but matching forward and reverse data can be desirable for some infrastructure, especially mail systems.

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Related tools

DNS LookupInspect DNS records for a domain. IP / ASN LookupFind the network announcing an IP address. My IPSee your current public address.