ntpsin3.ntppool.net has no CNAME records.
Question and response
Question
dig ntpsin3.ntppool.net. NS
Answer
The response has no answer records.
Authority
ntppool.net. 229 SOA ns1.us.bitnames.com. dnsoper.bitnames.com. 2026022201 600 900 3628800 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0