Apex domains cannot have CNAME records.
Question and response
Question
dig ippnet.fi. NS
Answer
ippnet.fi. 5 NS ns4.netorek.fi.
ippnet.fi. 5 NS ns3.netorek.fi.
Authority
The response has no authority records.
Additional
ns3.netorek.fi. 5 A 62.106.63.5
ns4.netorek.fi. 5 A 62.106.63.6
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0