mx2.superdata.vn has no NS records.
NS records for this zone are defined at superdata.vn.
NS records for this zone are defined at superdata.vn.
Question and response
Question
dig mx2.superdata.vn. NS
Answer
The response has no answer records.
Authority
superdata.vn. 3600 SOA nsbak.dotvndns.com. hostmaster.superdata.vn. 2026021255 14400 3600 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0