ns2.dynu.com has no CNAME records.
Question and response
Question
dig ns2.dynu.com. NS
Answer
The response has no answer records.
Authority
dynu.com. 2732 SOA ns1.dynu.com. administrator.dynu.com. 76206816 1800 300 86400 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0