Apex domains cannot have CNAME records.
Question and response
Question
dig haip.transip.net. NS
Answer
haip.transip.net. 4 NS ptr0.transip.nl.
haip.transip.net. 4 NS ptr2.transip.nl.
haip.transip.net. 4 NS ptr1.transip.nl.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0