ns2.cnchestnut.com has no CNAME records.
Question and response
Question
dig ns2.cnchestnut.com. NS
Answer
The response has no answer records.
Authority
cnchestnut.com. 5949 SOA ns1.cnchestnut.com. postmaster.cnchestnut.com. 2026012911 28800 7200 1209600 10800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0