dbrwirnap01.dnb.com has no CNAME records.
Question and response
Question
dig dbrwirnap01.dnb.com. NS
Answer
The response has no answer records.
Authority
dnb.com. 1304 SOA primaryns.dnb.com. dnsadmin.dnb.com. 2021085014 1200 600 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0