ns3.project4.pl has no CNAME records.
Question and response
Question
dig ns3.project4.pl. NS
Answer
The response has no answer records.
Authority
project4.pl. 600 SOA ns1.project4.pl. dnsmaster.project4.pl. 2025102102 7200 3600 2592000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0