Apex domains cannot have CNAME records.
Question and response
Question
dig exsbs.net. NS
Answer
exsbs.net. 2 NS ns1.exsbs.net.
exsbs.net. 2 NS VNS1.DAGENT.COM.
exsbs.net. 2 NS ns2.exsbs.net.
Authority
The response has no authority records.
Additional
ns1.exsbs.net. 2 A 63.73.11.2
ns2.exsbs.net. 2 A 63.73.11.3
vns1.dagent.com. 2 A 63.73.11.5
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0