Apex domains cannot have CNAME records.
Question and response
Question
dig edu.ee. NS
Answer
edu.ee. 5 NS ns.eenet.ee.
edu.ee. 5 NS ns2.eenet.ee.
Authority
The response has no authority records.
Additional
ns.eenet.ee. 5 A 193.40.56.242
ns2.eenet.ee. 5 A 193.40.0.11
ns.eenet.ee. 5 AAAA 2001:bb8:0:0:0:0:0:242
ns2.eenet.ee. 5 AAAA 2001:bb8:2001:0:0:0:0:11
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0