ip-103.133.97.83.dgtek.net has no CNAME records.
Question and response
Question
dig ip-103.133.97.83.dgtek.net. NS
Answer
The response has no answer records.
Authority
dgtek.net. 92 SOA ns-860.awsdns-43.net. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0