db2.dotarai.com has no CNAME records.
Question and response
Question
dig db2.dotarai.com. NS
Answer
The response has no answer records.
Authority
dotarai.com. 2552 SOA ns.mail.in.th. hostmaster\.mail.in.th. 2026011331 86400 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0