fe4.msk.ru.itoolabs.net has no CNAME records.
Question and response
Question
dig fe4.msk.ru.itoolabs.net. NS
Answer
The response has no answer records.
Authority
msk.ru.itoolabs.net. 244 SOA dns1.itoolabs.net. noc.itoolabs.net. 2026020501 28800 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0