Apex domains cannot have CNAME records.
Question and response
Question
dig thenetworkfactory.nl. NS
Answer
thenetworkfactory.nl. 5 NS ns1.es.vodafone.nl.
thenetworkfactory.nl. 5 NS ns2.es.vodafone.nl.
Authority
The response has no authority records.
Additional
ns1.es.vodafone.nl. 5 A 83.137.137.44
ns2.es.vodafone.nl. 5 A 212.78.209.5
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0