dnsst2.samsung.com has no NS records.
NS records for this zone are defined at samsung.com.
NS records for this zone are defined at samsung.com.
Question and response
Question
dig dnsst2.samsung.com. NS
Answer
The response has no answer records.
Authority
samsung.com. 300 SOA auth01.nhn.ic. ssdomain.samsung.com. 2020085332 10800 3600 2419200 300
Additional
. 0 OPT ; payload 1220, xrcode 0, version 0, flags 0