ip30.necoss.net has no CNAME records.
Question and response
Question
dig ip30.necoss.net. NS
Answer
The response has no answer records.
Authority
necoss.net. 5402 SOA ns1.starnet.cz. radek.krejca.starnet.cz. 2024062704 28800 14400 3600000 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0