mail.esc-rushydro.ru has no NS records.
NS records for this zone are defined at esc-rushydro.ru.
NS records for this zone are defined at esc-rushydro.ru.
Question and response
Question
dig mail.esc-rushydro.ru. NS
Answer
The response has no answer records.
Authority
esc-rushydro.ru. 600 SOA ns3-l2.nic.ru. baueraa.gidroogk.ru. 65012900 14400 3600 2592000 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0