b.westconcomstor.com has no CNAME records.
Question and response
Question
dig b.westconcomstor.com. NS
Answer
The response has no answer records.
Authority
westconcomstor.com. 1800 SOA ns3.westcon.com. dnsadmin.westcon.com. 2026012901 43200 600 2419200 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0