mx.anet.net.tw has no NS records.
NS records for this zone are defined at anet.net.tw.
NS records for this zone are defined at anet.net.tw.
Question and response
Question
dig mx.anet.net.tw. NS
Answer
The response has no answer records.
Authority
anet.net.tw. 600 SOA dns1.tfn.net.tw. dns_admin.tfn.net.tw. 2025062601 10800 3600 86400 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0