info.cyf-kr.edu.pl has no CNAME records.
Question and response
Question
dig info.cyf-kr.edu.pl. NS
Answer
The response has no answer records.
Authority
cyf-kr.edu.pl. 2221 SOA nms.cyf-kr.edu.pl. hostmaster.cyf-kr.edu.pl. 2026021700 86400 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0