dns2.edu.cn has no NS records.
NS records for this zone are defined at edu.cn.
NS records for this zone are defined at edu.cn.
Question and response
Question
dig dns2.edu.cn. NS
Answer
The response has no answer records.
Authority
edu.cn. 21600 SOA dns.edu.cn. hostmaster.net.edu.cn. 2026030481 7200 1800 604800 21600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0