cyborg.cpu.lublin.pl has no CNAME records.
Question and response
Question
dig cyborg.cpu.lublin.pl. NS
Answer
The response has no answer records.
Authority
cpu.lublin.pl. 10800 SOA ns1.lublin.pl. dns.man.lublin.pl. 9907479 14400 7200 2419200 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0