Reverse DNS lookup
Reverse DNS starts with an IP address and asks for its PTR record. Address-space owners normally control the reverse zone.
Enter a public IPv4 or IPv6 address.
How reverse DNS is used
PTR records provide a hostname for an address. They are useful for diagnostics, logs, network inventory, and mail-server identity, but they do not prove who operates a service.
For mail systems, administrators often configure forward-confirmed reverse DNS: the PTR hostname resolves forward to the original address. Many receivers use that consistency as one reputation signal.
If the PTR record is missing
- Ask the hosting or network provider that controls the IP allocation.
- Choose a stable hostname that resolves back to the address.
- Keep the SMTP banner and mail-server identity consistent where appropriate.
- Do not expect changing the domain’s normal DNS zone to change reverse DNS.
Quick answers
Frequently asked questions
Can I create a PTR record at my domain registrar?
Usually not. PTR records are managed by the organization controlling the IP address or its delegated reverse zone.
Can one address have multiple PTR records?
DNS permits it, but many applications expect one clear canonical hostname and multiple PTR answers can be counterproductive.