Apex domains cannot have CNAME records.
Question and response
Question
dig route25.eu. NS
Answer
route25.eu. 5 NS ns023.auroradns.info.
route25.eu. 5 NS ns022.auroradns.nl.
route25.eu. 5 NS ns021.auroradns.eu.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0