DNS delegation of mx.mail.yahoo.com updated: May 23, 2013 12:58:33 PM
Delegation
step
query
auth
servers
1
mx.mail.yahoo.com.
.
(m,g,c,d,a,k,j,i,b,h,f,l,e).root-servers.net.
2
mx.mail.yahoo.com.
com.
(e,l,d,f,b,k,m,a,g,j,c,i,h).gtld-servers.net.
3
mx.mail.yahoo.com.
yahoo.com.
(ns4,ns1,ns5,ns3,ns2).yahoo.com.
4
content.mail.yahoo.com.
yahoo.com.
(ns3,ns5,ns1,ns2,ns4).yahoo.com.
5
content1.mail.am0.yahoodns.net.
.
(e,g,b,d,a,m,h,j,l,k,i,c,f).root-servers.net.
6
content1.mail.am0.yahoodns.net.
net.
(b,h,d,c,a,f,i,k,e,g,l,m,j).gtld-servers.net.
7
content1.mail.am0.yahoodns.net.
yahoodns.net.
(ns1,ns2,ns4,ns3,ns5).yahoo.com.
8
content1.mail.am0.yahoodns.net.
am0.yahoodns.net.
(yf1,yf2).yahoo.com.
We pick m.root-servers.net, one of the 13 root servers (1), and ask it about mx.mail.yahoo.com and learn that com is delegated to 13 name servers (2), so we ask e.gtld-servers.net where we learn that yahoo.com is delegated to five name servers, including ns4.yahoo.com (3), so we ask that one where we see a CNAME from mx.mail.yahoo.com to content.mail.yahoo.com, so we have to start all over again. We already know that ns3.yahoo.com is authoritative for yahoo.com (4) and ask it about content.mail.yahoo.com and see a second CNAME from content.mail.yahoo.com to content1.mail.am0.yahoodns.net. We start over for the third time and we pick e.root-servers.net, one of the 13 root servers (5), and ask it about content1.mail.am0.yahoodns.net and learn that net is delegated to 13 name servers (6), so we ask b.gtld-servers.net where we learn that yahoodns.net is delegated to five name servers, including ns1.yahoo.com (7), so we ask that one and learn that am0.yahoodns.net is delegated to two name servers (8), so we ask yf1.yahoo.com and get the following answer:
