dns.smart has no NS records.
NS records for this zone are defined at smart.
NS records for this zone are defined at smart.
Question and response
Question
dig dns.smart. NS
Answer
The response has no answer records.
Authority
smart. 900 SOA ns0.centralnic.net. hostmaster.centralnic.net. 1773087314 60 1800 6048000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0