IP Whois

Where the data comes from

Every block of addresses is assigned to one of five regional registries: ARIN, RIPE NCC, APNIC, LACNIC or AFRINIC. The tool finds the right one through the IANA lists and queries it directly. If a block has been transferred to another registry or a national one, such as the Brazilian NIC.br, the query follows it, so an early ARIN block will return its actual owner from RIPE.

The response shows the network and its boundaries, the owner, the country, an abuse contact and dates, with the registry's full reply below. The city where the network is registered, the reverse name and spam list checks are shown by IP address information.

Which addresses won't be found

Private networks like 192.168.x and 10.x, the loopback 127.0.0.1, shared carrier addresses from 100.64.0.0/10 and addresses reserved for documentation are not listed in the registries: each network has its own. The tool names such an address right away, without sending a query.

The abuse contact is set by the registry itself. For some Asian addresses it is a general mailbox of the national registry, for example KRNIC in Korea, rather than the provider.