Apex domains cannot have CNAME records.
Question and response
Question
dig ip.elisa.ee. NS
Answer
ip.elisa.ee. 5 NS ns1.elisa.ee.
ip.elisa.ee. 5 NS ns2.elisa.ee.
Authority
The response has no authority records.
Additional
ns1.elisa.ee. 5 A 194.204.0.1
ns2.elisa.ee. 5 A 85.253.0.1
ns1.elisa.ee. 5 AAAA 2001:1530:a:0:0:0:0:1
ns2.elisa.ee. 5 AAAA 2001:1bf0:a:0:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0