mail2.firstvds.ru has no NS records.
NS records for this zone are defined at firstvds.ru.
NS records for this zone are defined at firstvds.ru.
Question and response
Question
dig mail2.firstvds.ru. NS
Answer
The response has no answer records.
Authority
firstvds.ru. 3600 SOA ns1.ddos-guard.net. support.ddos-guard.net. 1764741782 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0