_netblocks.ipnet.kiev.ua has no CNAME records.
Question and response
Question
dig _netblocks.ipnet.kiev.ua. NS
Answer
The response has no answer records.
Authority
ipnet.kiev.ua. 4863 SOA ns.ip.net.ua. hostmaster.ip.net.ua. 2024040100 14400 3600 1209600 172800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0