We pick l.root-servers.net, one of the 13 root servers (1), and ask it about facebook.cm and learn that cm is delegated to six name servers (2), so we ask cm.cctld.authdns.ripe.net where we learn that facebook.cm is delegated to two name servers, including ns1.dnspanel.com (3), so we ask that one and get the following answer:
Every fifth of them point only to the IP number 85.25.146.60 (example: kc910.com, weetmeme.com and friendster.cm ). Worth noting is that one quarter of the host names that point only to the IP number 85.25.146.60 use name server group 1.
There are several hundred of host names that point only to the IP number 85.25.146.60.
One quarter of those use name server group 1 (example: 4megauploadcom.com, cingularwireless.co and horan.com ). Worth noting is that about one in six of the domains that use name server group 1 point only to the IP number 85.25.146.60.