msk.frontend.epserv.ru has no NS records.
NS records for this zone are defined at epserv.ru.
NS records for this zone are defined at epserv.ru.
Question and response
Question
dig msk.frontend.epserv.ru. NS
Answer
The response has no answer records.
Authority
epserv.ru. 1800 SOA alla.ns.cloudflare.com. dns.cloudflare.com. 2397538176 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0