sin.as30781.net has no CNAME records.
Question and response
Question
dig sin.as30781.net. NS
Answer
The response has no answer records.
Authority
as30781.net. 1800 SOA ns1.as30781.net. hostmaster.as30781.net. 2026022601 21600 3600 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0