Reverse DNS delegation

What is reverse DNS?

The Domain Name System (DNS) is a globally distributed Internet service. Among other services, 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 and any user is freely able to query the DNS system for forward or reverse translations.

Reverse DNS delegations allow requesters to map to a domain name from an IP address. Reverse delegation is achieved by the use of pseudo-domain names in-addr.arpa (IPv4) and ip6.arpa (IPv6). APNIC only registers reverse delegations, and is not directly involved in other aspects of the domain name registration system.

APNIC reverse DNS services

APNIC provides reverse delegation services to Members and Non-Members that hold a block of IP addresses.

IANA delegates reverse DNS zones within the centrally-administered 'in-addr.arpa' and ip6.arpa zones.

Any organization that has received IP addresses from APNIC should register their reverse domain with APNIC so that their reverse DNS works globally.

Responsibilities

Members

Being familiar with APNIC procedures
Ensuring that addresses are reverse-mapped
Maintaining nameservers for allocations (to minimize pollution of the DNS)

APNIC

Managing reverse delegations of address block distributed by APNIC
Processing members requests for reverse delegations of network allocations

Manage Reverse DNS

User Guides

Why bother?

Service denial
That only allow access when fully reverse delegated eg., anonymous ftp
Diagnostics
Assisting in trace routes etc.
Spam identification
Registration
Responsibility as a member and Local IR

Note: APNIC only registers reverse delegations and is not involved in the domain name registration system.