dns2.cnsnext.com has no CNAME records.
Question and response
Question
dig dns2.cnsnext.com. NS
Answer
The response has no answer records.
Authority
cnsnext.com. 3523 SOA dns1.cnsnext.com. noc.cns-internet.com. 2026011301 10800 3600 604800 38400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0