DNS delegation of ww.facebok.com updated: May 20, 2013 7:08:43 AM
Delegation
step
query
auth
servers
1
ww.facebok.com.
.
(k,i,c,e,h,m,d,g,l,j,a,b,f).root-servers.net.
2
ww.facebok.com.
com.
(m,d,g,f,k,c,l,e,b,i,j,h,a).gtld-servers.net.
3
ww.facebok.com.
facebok.com.
(b,a).ns.facebook.com.
4
www.facebook.com.
com.
(d,l,f,e,i,b,h,k,g,c,m,a,j).gtld-servers.net.
5
www.facebook.com.
facebook.com.
(a,b).ns.facebook.com.
6
star.c10r.facebook.com.
facebook.com.
(b,a).ns.facebook.com.
7
star.c10r.facebook.com.
c10r.facebook.com.
(b,a).ns.c10r.facebook.com.
We pick k.root-servers.net, one of the 13 root servers (1), and ask it about ww.facebok.com and learn that com is delegated to 13 name servers (2), so we ask m.gtld-servers.net where we learn that facebok.com is delegated to two name servers, including b.ns.facebook.com (3), so we ask that one where we see a CNAME from ww.facebok.com to www.facebook.com, so we have to start all over again. We already know that d.gtld-servers.net is authoritative for com (4) and ask it about www.facebook.com and learn that facebook.com is delegated to two name servers (5), so we ask a.ns.facebook.com and see a second CNAME from www.facebook.com to star.c10r.facebook.com. We start over for the third time and we already know that b.ns.facebook.com is authoritative for facebook.com (6) and ask it about star.c10r.facebook.com and learn that c10r.facebook.com is delegated to two name servers (7), so we ask b.ns.c10r.facebook.com and get the following answer: