mail.dnepro.net has no NS records.
NS records for this zone are defined at dnepro.net.
NS records for this zone are defined at dnepro.net.
Question and response
Question
dig mail.dnepro.net. NS
Answer
The response has no answer records.
Authority
dnepro.net. 1800 SOA ns.dnepro.net. root.dnepro.net. 2016062735 36000 300 60480 8640
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0