199.static.tfn.net.tw has no NS records.
NS records for this zone are defined at static.tfn.net.tw.
NS records for this zone are defined at static.tfn.net.tw.
Question and response
Question
dig 199.static.tfn.net.tw. NS
Answer
The response has no answer records.
Authority
static.tfn.net.tw. 86400 SOA dns1.tfn.net.tw. dns_admin.tfn.net.tw. 2018052405 86400 3600 1209600 604800
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0