DNS delegation of cn.yahoo.com updated: May 25, 2013 5:20:01 PM
Delegation
step
query
auth
servers
1
cn.yahoo.com.
.
(b,j,f,m,g,a,h,c,k,d,e,i,l).root-servers.net.
2
cn.yahoo.com.
com.
(h,g,j,d,f,c,b,k,l,m,e,i,a).gtld-servers.net.
3
cn.yahoo.com.
yahoo.com.
(ns2,ns4,ns1,ns3,ns5).yahoo.com.
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 (202.165.102.205), which also has a corresponding reverse pointer.
There are six host names that point to the IP number 202.165.102.205.
All of those point only to that ip number (example: yahoo.com.cn ).
Four of them use the name server ns9.yahoo.com. Worth noting is that four of the domains that use the name server ns9.yahoo.com point to the IP number 202.165.102.205.
Four of them use the name server ns8.yahoo.com. Worth noting is that four of the domains that use the name server ns8.yahoo.com point to the IP number 202.165.102.205.
The IP number 202.165.102.205 only
Four of the six host names that point only to the IP number 202.165.102.205 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 202.165.102.205.
The name server ns9.yahoo.com
Four of the seven domains that use the name server ns9.yahoo.com point to the IP number 202.165.102.205. Worth noting is that four of the host names that point to the IP number 202.165.102.205 use the name server ns9.yahoo.com.
The mail server. Only
There are several thousand of domains that only use the mail server ..