mail.gazsvyaz.ru has no NS records.
NS records for this zone are defined at gazsvyaz.ru.
NS records for this zone are defined at gazsvyaz.ru.
Question and response
Question
dig mail.gazsvyaz.ru. NS
Answer
The response has no answer records.
Authority
gazsvyaz.ru. 3600 SOA ns.gazprom.ru. sysadm.gazprom.ru. 2026012707 7200 900 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0