Apex domains cannot have CNAME records.
Question and response
Question
dig baernet.net. NS
Answer
baernet.net. 5 NS docks16.rzone.de.
baernet.net. 5 NS shades05.rzone.de.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0