Apex domains cannot have CNAME records.
Question and response
Question
dig int.4net.tv. NS
Answer
int.4net.tv. 5 NS ns1.int.4net.tv.
int.4net.tv. 5 NS ns0.int.4net.tv.
Authority
The response has no authority records.
Additional
ns0.int.4net.tv. 5 A 91.222.55.43
ns1.int.4net.tv. 5 A 91.222.55.9
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0