dns2.pwr.edu.pl has no CNAME records.
Question and response
Question
dig dns2.pwr.edu.pl. NS
Answer
The response has no answer records.
Authority
pwr.edu.pl. 7200 SOA dns1.pwr.edu.pl. dns.pwr.edu.pl. 2026030603 3600 300 1209600 7200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0