ns2.srv.in.th has no NS records.
NS records for this zone are defined at srv.in.th.
NS records for this zone are defined at srv.in.th.
Question and response
Question
dig ns2.srv.in.th. NS
Answer
The response has no answer records.
Authority
srv.in.th. 1800 SOA jill.ns.cloudflare.com. dns.cloudflare.com. 2394611272 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0