rostov-vr.smartspb.net has no NS records.
NS records for this zone are defined at smartspb.net.
NS records for this zone are defined at smartspb.net.
Question and response
Question
dig rostov-vr.ra.smartspb.net. NS
Answer
The response has no answer records.
Authority
smartspb.net. 600 SOA ns4.smartspb.net. hostmaster.smartspb.net. 931 28800 1800 1209600 28800
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0