Apex domains cannot have CNAME records.
Question and response
Question
dig datanet.ee. NS
Answer
datanet.ee. 2 NS ns.eunet.ee.
datanet.ee. 2 NS ns.data.ee.
Authority
The response has no authority records.
Additional
ns.data.ee. 2 A 195.222.4.1
ns.eunet.ee. 2 A 195.222.0.1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0