dnsg01.yahoo.co.jp has one IP number , which also has a corresponding reverse pointer. yimg.jp, yahoo.jp, flya.com, dosule.com, yahoofs.jp and at least 100 other hosts use this as a nameserver. yahoo.co.jp is a domain controlled by two nameservers on different IP networks. Incoming mail for yahoo.co.jp is handled by four mailservers having a total of 14 IP numbers. Some of them are on the same IP network. yahoo.co.jp has two IP numbers. They are on different IP networks. dnsg01.yahoo.co.jp is hosted on a server in Japan.