Apex domains cannot have CNAME records.
Question and response
Question
dig noffer.de. NS
Answer
noffer.de. 5 NS shades11.rzone.de.
noffer.de. 5 NS docks17.rzone.de.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0