Guide - Public availability of reverse DNS zones

Introduction
Access to reverse DNS data
Access to reverse DNS data by whois query
Bulk access to whois data
Access to reverse DNS data by FTP
Access to reverse DNS by zone query

Introduction

The Domain Name System (DNS) is a globally-distributed Internet service. It provides name-to-number (forward) and number-to-name (reverse) translations, using defined client-server and server-server protocols. The DNS is a public service - any Internet user is freely able to query the DNS system for forward or reverse translations.

For all IP address blocks IANA allocates to APNIC, IANA also delegates corresponding reverse DNS zones within the centrally-administered 'in-addr.arpa' and 'ip6.arpa' zones. The lists of reverse DNS zones currently maintained by APNIC are available at:

IANA reports

APNIC also publishes 'zone fragments'. Zone fragments are the parts of zones managed by other parties, namely:

the other Regional Internet Registries (RIRs), who share zone management of early registration networks; and
the National Internet Registries (NIRs) who manage IP address space allocated to them for further distribution to their members.