Apex domains cannot have CNAME records.
Question and response
Question
dig ns.iskyhost.net. NS
Answer
ns.iskyhost.net. 5 NS ns1.iskyhost.net.
ns.iskyhost.net. 5 NS ns3.iskyhost.net.
ns.iskyhost.net. 5 NS ns2.iskyhost.net.
Authority
The response has no authority records.
Additional
ns1.iskyhost.net. 3 A 23.88.5.235
ns2.iskyhost.net. 3 A 188.245.38.161
ns3.iskyhost.net. 3 A 93.170.73.175
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0