go
ns1.dom.yahoo.co.jp, ns2.dom.yahoo.co.jp, dns1.dom.yahoo.co.jp, ns04.dom.yahoo.co.jp, dns2.dom.yahoo.co.jp and at least eight other hosts are subdomains to this hostname. 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 ten IP numbers. There are four duplicated IP numbers. Some of them are on the same IP network. yahoo.co.jp has two IP numbers. They are on different IP networks.

yahoo.co.jp
a records
 
+ 124.83.139.192 124.83.128.0/17 AS24572  
+ ---  
+ 203.216.227.176 203.216.224.0/19 AS23816  
ns-soa records
yahoo.co.jp
+ 124.83.139.192 124.83.128.0/17 AS24572  
+ ---  
+ 203.216.227.176 203.216.224.0/19 AS23816  
ns records
dnsg01.yahoo.co.jp
+ 211.14.12.10 211.14.12.0/22 AS23816 -
+ --- -
ns04.ops.ogk.yahoo.co.jp
+ 124.83.218.185 124.83.128.0/17 AS24572 -
mx records
mx1.mail.yahoo.co.jp
+ 124.83.171.244 124.83.128.0/17 AS24572 oa5.mobile.vip.ogk.yahoo.co.jp
+ --- oa5.mobile.vip.ogk.yahoo.co.jp
+ 124.83.207.138 124.83.128.0/17 AS24572 mta302.mail.vip.ogk.yahoo.co.jp
+ --- mta302.mail.vip.ogk.yahoo.co.jp
mx2.mail.yahoo.co.jp
+ 124.147.39.208 124.147.32.0/19 AS23816 mta24.mail.vip.kcd.yahoo.co.jp
+ --- mta24.mail.vip.kcd.yahoo.co.jp
+ 124.147.39.209 124.147.32.0/19 AS23816 mta23.mail.vip.kcd.yahoo.co.jp
+ --- mta23.mail.vip.kcd.yahoo.co.jp
+ 203.216.243.170 203.216.224.0/19 AS23816 mta18.mail.vip.tnz.yahoo.co.jp
+ --- mta18.mail.vip.tnz.yahoo.co.jp
+ 203.216.243.171 203.216.224.0/19 AS23816 mta17.mail.vip.tnz.yahoo.co.jp
+ --- mta17.mail.vip.tnz.yahoo.co.jp
mx3.mail.yahoo.co.jp
+ 124.147.39.207 124.147.32.0/19 AS23816 mta25.mail.vip.kcd.yahoo.co.jp
+ --- mta25.mail.vip.kcd.yahoo.co.jp
+ 124.147.39.208 124.147.32.0/19 AS23816 mta24.mail.vip.kcd.yahoo.co.jp
+ --- mta24.mail.vip.kcd.yahoo.co.jp
+ 124.147.39.209 124.147.32.0/19 AS23816 mta23.mail.vip.kcd.yahoo.co.jp
+ --- mta23.mail.vip.kcd.yahoo.co.jp
+ 203.216.243.173 203.216.224.0/19 AS23816 mta15.mail.vip.tnz.yahoo.co.jp
+ --- mta15.mail.vip.tnz.yahoo.co.jp
mx5.mail.yahoo.co.jp
+ 203.216.243.170 203.216.224.0/19 AS23816 mta18.mail.vip.tnz.yahoo.co.jp
+ --- mta18.mail.vip.tnz.yahoo.co.jp
+ 203.216.243.171 203.216.224.0/19 AS23816 mta17.mail.vip.tnz.yahoo.co.jp
+ --- mta17.mail.vip.tnz.yahoo.co.jp
+ 203.216.243.172 203.216.224.0/19 AS23816 mta16.mail.vip.tnz.yahoo.co.jp
+ --- mta16.mail.vip.tnz.yahoo.co.jp
+ 203.216.247.184 203.216.224.0/19 AS23816 mta19.mail.vip.tnz.yahoo.co.jp
+ --- mta19.mail.vip.tnz.yahoo.co.jp
subdomains
cds01.dom.yahoo.co.jp
ciajfk1963.dom.yahoo.co.jp
dns1.dom.yahoo.co.jp
dns2.dom.yahoo.co.jp
dns3.dom.yahoo.co.jp
fcb24.dom.yahoo.co.jp
ns01.dom.yahoo.co.jp
ns02.dom.yahoo.co.jp
ns03.dom.yahoo.co.jp
ns04.dom.yahoo.co.jp
ns1.dom.yahoo.co.jp
ns2.dom.yahoo.co.jp
smtp01.dom.yahoo.co.jp