Apex domains cannot have CNAME records.
Question and response
Question
dig lsmod.de. NS
Answer
lsmod.de. 5 NS ns11.prosite.de.
lsmod.de. 5 NS ns12.prosite.de.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0