ns4.dns2b.ru has no CNAME records.
Question and response
Question
dig ns4.dns2b.ru. NS
Answer
The response has no answer records.
Authority
dns2b.ru. 961 SOA ns1.dns2b.ru. hostmaster.dns2b.ru. 2026030501 10800 3600 2419200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0