Reverse DNS
Resolves an IP address (or a domain's IPs) back to a hostname via PTR records. Important for mail server identity (matching forward and reverse DNS) and general server hygiene.
Frequently asked questions
- What is reverse DNS for?
- It maps an IP back to a hostname (PTR record). Mail servers especially care — a sending IP without matching forward and reverse DNS is often rejected as spam.
- Why does my IP have no PTR record?
- Most ISPs set generic PTRs for residential IPs (e.g. dynamic-1-2-3-4.isp.com). For servers, ask your hosting provider to set it, or configure it yourself if you control the rDNS zone.
- Can I change my PTR record?
- Only the owner of the IP block can. For leased servers, open a ticket with your provider. For your own BGP-announced subnet, configure reverse DNS via your RIR (RIPE, ARIN, etc.).