mx2.dynu.com has no NS records.
NS records for this zone are defined at dynu.com.
NS records for this zone are defined at dynu.com.
Question and response
Question
dig mx2.dynu.com. NS
Answer
The response has no answer records.
Authority
dynu.com. 3600 SOA ns1.dynu.com. administrator.dynu.com. 76193390 1800 300 86400 1800
Additional
. 0 OPT ; payload 1280, xrcode 0, version 0, flags 0