We pick f.root-servers.net, one of the 13 root servers (1), and ask it about root-servers.cn and learn that cn is delegated to six name servers (2), so we ask b.dns.cn where we learn that root-servers.cn is delegated to three name servers, including ns2.cdns.cn (3), so we ask that one and get the following answer:
Root-servers.cn is a domain controlled by three domain name servers at cdns.cn having a total of three IP numbers. Two of them are on the same IP network. We are missing the IP:s of two servers: ns2.cdns.cn and ns1.cdns.cn. Incoming mail for root-servers.cn is handled by one mail server at qq.com. We are missing the IP:s of one server: mxdomain.qq.com.
All of them use the primary name server ns1.cdns.cn (example: tjskl.org.cn, ertu.cn and seofans.cn ). Worth noting is that most of the domains that use the primary name server ns1.cdns.cn use name server group 1.
Most of the more than hundred domains that use the primary name server ns1.cdns.cn use name server group 1 (example: xy2s.cn, no114.cn and guarder.cn ). Worth noting is that all of the domains that use name server group 1 use the primary name server ns1.cdns.cn.
The mail server mxdomain.qq.com only
There are several thousand of domains that only use the mail server mxdomain.qq.com.
