Apex domains cannot have CNAME records.
Question and response
Question
dig seclan.fi. NS
Answer
seclan.fi. 5 NS ns2-fin.seclan.fi.
seclan.fi. 5 NS ns3-fin.seclan.fi.
seclan.fi. 5 NS ns1-fin.seclan.fi.
Authority
The response has no authority records.
Additional
ns1-fin.seclan.fi. 5 A 109.70.160.110
ns2-fin.seclan.fi. 5 A 109.70.160.111
ns3-fin.seclan.fi. 5 A 81.19.115.162
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0