Ask the routing table.
A demonstration of the public service, answered live from whois.pwhois.org. Pick what you want to ask about, watch the exact query take shape, and read the answer as the server sent it — or prettified. For anything scripted or bulk, query port 43 directly: it is built for volume, this page is not.
From your command line
Everything this page builds is an ordinary whois query — the first line in the preview above works in any whois client pointed at whois.pwhois.org. Our WhoB client adds the second line: -g parses the answer down to one line, and -e tags every address in whatever you pipe through it.
Thousands at once — wrap a list in begin / end and pipe it in with netcat. Only the native and Cymru formats support bulk output.
Query etiquette
This page is a demonstration; do not script against it. The real service is port 43 and is built for
volume: use bulk mode rather than one connection per address, cache answers for at least the
Cache-Date interval, and prefer type=json if you are parsing.
Unregistered sources get a daily allowance sufficient for a few thousand queries. Need more? Tell us who you are and which static IPs you query from and we will very likely raise it — free for education, research and government use.