pjhtech Tools
Address planning

Reverse DNS / PTR Converter

Build IPv4 host reverse names and IPv6 host or nibble-aligned reverse-zone names.

Input

Reset restores the example inputs.

Local calculation · inputs are not sent to a server.

Result

Calculating the example…

Enter one IPv4 or IPv6 host to get its PTR owner name. Enter an IPv6 prefix to get its reverse-zone name. Add the record or delegation through the DNS service responsible for that address space.

Example: 10.42.7.93 becomes 93.7.42.10.in-addr.arpa. For 2001:db8:42::/48, the zone is 2.4.0.0.8.b.d.0.1.0.0.2.ip6.arpa.

This tool creates a DNS name; it does not publish a record or run a lookup. IPv6 zone prefixes must be multiples of four. IPv4 CIDRs are rejected: enter a single host, or plan classless reverse delegation separately.

References