ns2.dnsbolt.com has no CNAME records.
Question and response
Question
dig ns2.dnsbolt.com. NS
Answer
The response has no answer records.
Authority
dnsbolt.com. 8946 SOA ns1.dnsbolt.com. Postmaster.dnsbolt.com. 337728744 10800 3600 172800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0