mx1.cvent-planner.com has no NS records.
NS records for this zone are defined at cvent-planner.com.
NS records for this zone are defined at cvent-planner.com.
Question and response
Question
dig pr50-mxa-nlb-c7367eb145d43597.elb.us-east-1.amazonaws.com. NS
Answer
The response has no answer records.
Authority
elb.us-east-1.amazonaws.com. 60 SOA ns-1826.awsdns-36.co.uk. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 60
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0