Reverse DNS

What is reverse DNS?

Reverse DNS is the process of mapping IP addresses to domains. Since DNS maps domains to IP addresses, if you want to determine whether an IP address corresponds to one or more domains, you need to traverse the entire domain name system, which is impossible. Therefore, RFC1035 defines a pointer (PTR) record as a data type in the mailbox system. In contrast to an A record, a PTR record points an IP address to a domain.

Reverse DNS is mostly used in mail servers. After it is enabled, messages from IPs with no domains registered can be rejected. As most spammers use dynamically assigned IPs or IPs with no domains registered to send spam emails while staying anonymous, spam can be prevented by rejecting messages from IP addresses that cannot be resolved back to domains on the server.

As detailed above, reverse DNS cannot be completed by a DNS service provider. Instead, you need to contact your ISP to configure reverse DNS.

Does DNSPod support reverse DNS?

No.