ns2.ipptr.com has no CNAME records.
Question and response
Question
dig ns2.ipptr.com. NS
Answer
The response has no answer records.
Authority
ipptr.com. 5154 SOA ns1.ipptr.com. san2roy.gmail.com. 1525861377 10800 3600 604800 38400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0