Networking >> Internet >>  Where to lookup owner of IP addresses

delegated-registrar by 1st class-A network:- - http://www.iana.org/assignments/ipv4-address-space specific ip address, visit the respective IP registrar APNIC (Asia Pacific):- - http://www.apnic.net, use their whois tool ARIN (Americas and Africa) - http://www.arin.net, use their whois tool RIPE (Europe and surrounding) - http://www.ripe.net