Policy For Reverse Address Delegation of IPv4 And IPv6 Address Space in the RIPE NCC Service Region
This document describes the policy for reverse delegation of IPv4 and IPv6 address space in the RIPE NCC service region.
The RIPE NCC provides, as part of its services, the necessary support to enable the reverse resolution of IPv4 and IPv6 address space into domain names. This service is implemented under the in-addr.arpa and ip6.arpa sub-domains described in  and .
Reverse delegations for IPv4 and IPv6 addresses allocated by the RIPE NCC are made to Local Internet Registries (LIRs) and further delegated by the LIRs to Internet Service Providers or End Users.
The RIPE NCC provides reverse delegation for address space that has been allocated or assigned by the RIPE NCC. It also provides systems to control reverse delegations relating to early registrations that have been transferred to the RIPE Database. Registrants of address space allocations or assignments may delegate authority for requesting reverse delegation from the RIPE NCC.
The RIPE NCC accepts requests for reverse delegation for address space that has been allocated by the RIPE NCC to an LIR or, in the case of PI address space, an assignment that has been made to an End User.
The procedures for requesting and modifying reverse delegation and information about the requirements the RIPE NCC enforces to maintain the quality of the reverse delegations are published at:
 "Management Guidelines & Operational Requirements for the Address and Routing Parameter Area Domain ("arpa")"
 "DNS Extensions to Support IPv6 Address Aggregation and Renumbering" [RFC 2874]