ttk-proxy.dc1.ru.itoolabs.net has no CNAME records.
Question and response
Question
dig ttk-proxy.dc1.ru.itoolabs.net. NS
Answer
The response has no answer records.
Authority
dc1.ru.itoolabs.net. 1207 SOA dns1.itoolabs.net. noc.itoolabs.net. 2026012001 28800 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0