What you can learn about an IP address
An IP address on its own is just a number, but there is plenty of public data around it. We gather it from several sources in one place:
- Address type — public, private, CGNAT, loopback, multicast or reserved for documentation.
- PTR record — the hostname the network owner has assigned to the address. Mail servers must have one.
- Registry data — the network range, owning organization and abuse contact from the regional registry (RIPE NCC, ARIN, APNIC and others).
- Autonomous system — the provider announcing this network on the internet.
- Other notations — decimal, hexadecimal and binary forms, handy for programming and firewall configuration.
Use the subnet calculator to work out network boundaries from a mask, and ping to check whether a host is reachable.