ns4.iqvia.com has no CNAME records.
Question and response
Question
dig ns4.iqvia.com. NS
Answer
The response has no answer records.
Authority
iqvia.com. 3600 SOA ns1.iqvia.com. hostmaster.iqvia.com. 2026030802 28800 1800 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0