Apex domains cannot have CNAME records.
Question and response
Question
dig asp4all.nl. NS
Answer
asp4all.nl. 4 NS a10-67.akam.net.
asp4all.nl. 4 NS a12-65.akam.net.
asp4all.nl. 4 NS a26-64.akam.net.
asp4all.nl. 4 NS a3-64.akam.net.
asp4all.nl. 4 NS a1-167.akam.net.
asp4all.nl. 4 NS a5-67.akam.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0