s3.pop.niux88.com has no NS records.
NS records for this zone are defined at niux88.com.
NS records for this zone are defined at niux88.com.
Question and response
Question
dig s3.pop.niux88.com. NS
Answer
The response has no answer records.
Authority
niux88.com. 3601 SOA dns1.registrar-servers.com. hostmaster.registrar-servers.com. 1766588557 43200 3600 604800 3601
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0