Perform a reverse DNS (PTR) lookup for all IPv4 addresses inside a /24 IPv4 CIDR block. A PTR record (Pointer Record) maps an IPv4 address to a hostname using the in-addr.arpa domain. This lookup reveals the domain names associated with all 256 IPv4 addresses in the block and is commonly used for diagnostics, network mapping, verification, logging, and security analysis.

Use !ptr24 to see the names (Pointer Records) of all the IP addresses in a /24 address block. Internet DNS Pointer Records, also known as IP-names or IP-reverses, are usually set by or in coordination with the organization that manages the IP addresses. Because of this, reverse DNS often reflects operational or organizational details about the entity controlling the IPv4 block.

Reverse DNS is also valuable in Internet forensics. PTR hostnames often reveal hosting providers, mail server infrastructure, CDN edges, load balancer clusters, and operational fingerprints. Analysts use block-level PTR lookups to understand service attribution, detect misconfigurations, and correlate IPv4 addresses with organizational or geographic hints.

Usually, !ptr is used for single IPv4 and IPv6 addresses, while !ptr24 is used for full /24 IPv4 blocks.

Usage:
!ptr24
Usage Examples:
!ptr24 8.8.8
!ptr24 8.8.8.8
!ptr24 1.1.1.0/24
!ptr24 66.22.32
!ptr24 66.22.32.10
!ptr24 188.165.34.35
!ptr24 188.165.31.0/24
!ptr24 4.2.2.0/24
!ptr24 216.108.235.216
!ptr24 134.68.34
!ptr24 9.9.9.0
!ptr24 1.1.1.0/24
!ptr24 3.2.1
!ptr24 192.55.83
!ptr24 188.165.33
!ptr24 193.29.59.104
!ptr24 204.74.99


See also:
!help !ptr