Reverse PTR Generator

Convert IP addresses and CIDR blocks to PTR record names and zone file examples

Reverse DNS: PTR records map IP addresses back to hostnames using in-addr.arpa (IPv4) and ip6.arpa (IPv6) zones.

PTR Names: Generated by reversing IP octets/nibbles and appending the appropriate arpa domain.

Zone Lines: Ready-to-use DNS zone file entries with proper PTR record format.

Quick Examples

Input Type

Single IP

CIDR Block

IP Address

PTR Records Generated

1 Total PTRs

1 IPv4

1 Zones

PTR Records & Zone Lines

IP Address

PTR Record Name

Zone File Line

Type

192.168.1.100

100.1.168.192.in-addr.arpa

100 IN PTR host-192-168-1-100.example.com.

IPv4

PTR Record Format

PTR records use the special in-addr.arpa (IPv4) and ip6.arpa (IPv6) domains. IP addresses are reversed: 192.168.1.100 becomes 100.1.168.192.in-addr.arpa.

Zone File Usage

The generated zone file lines can be copied directly into your reverse DNS zone files. Remember to adjust the hostname targets to match your actual domain structure.

IPv6 Nibbles

IPv6 PTR records use individual hex digits (nibbles) reversed. Each character becomes a separate label: 2001:db8::1 becomes a very long ip6.arpa name.

Best Practices

Ensure PTR records have corresponding A/AAAA records for proper forward-reverse DNS consistency. Use descriptive hostnames that include IP information for easier network management.