dns.sunplusit.com has no CNAME records.
Question and response
Question
dig dns.sunplusit.com. NS
Answer
The response has no answer records.
Authority
sunplusit.com. 2761 SOA dns.sunplusit.com. admin.sunplusit.com. 2026021011 7200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0