DNS delegation of cn.yahoo.com updated: May 25, 2013 5:20:01 PM
We pick b.root-servers.net, one of the 13 root servers (1), and ask it about cn.yahoo.com and learn that com is delegated to 13 name servers (2), so we ask h.gtld-servers.net where we learn that yahoo.com is delegated to five name servers, including ns2.yahoo.com (3), so we ask that one and get the following answer:
Cn.yahoo.com is a domain controlled by two domain name servers at yahoo.com. Both are on different IP networks. Incoming mail for cn.yahoo.com is handled by one mail server at .. We are missing the IP:s of one server: .. Cn.yahoo.com has one IP number (188.8.131.52), which also has a corresponding reverse pointer.
Four of the six host names that point only to the IP number 184.108.40.206 use the two name servers ns8 and ns9.yahoo.com together, hereafter referred to as "name server group 1". Worth noting is that all of the domains that use name server group 1 point only to the IP number 220.127.116.11.