ns2.rapidns.com has no CNAME records.
Question and response
Question
dig ns2.rapidns.com. NS
Answer
The response has no answer records.
Authority
rapidns.com. 9598 SOA ns1.rapidns.com. hostmaster.rapidns.com. 2026021000 28800 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0