ns4.register.it has one IP number , which also has a corresponding reverse pointer. zeca.us, swide.us, teuco.us, emmegi.us, oxyde.net and at least 46 other hosts use this as a nameserver. register.it is a domain controlled by two nameservers at register.it themselves. They are on different IP networks. Incoming mail for register.it is handled by one mailserver also at register.it. register.it has one IP number. ns4.register.it is hosted on a server in United States even though the hostname implies Italy.