Apex domains cannot have CNAME records.
Question and response
Question
dig interkonekt.pl. NS
Answer
interkonekt.pl. 5 NS dns.interkonekt.pl.
interkonekt.pl. 5 NS dns2.interkonekt.pl.
Authority
The response has no authority records.
Additional
dns.interkonekt.pl. 5 A 91.233.160.5
dns2.interkonekt.pl. 5 A 195.88.90.4
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0