Apex domains cannot have CNAME records.
Question and response
Question
dig dagent.com. NS
Answer
dagent.com. 1 NS ns2.exsbs.net.
dagent.com. 1 NS vns1.dagent.com.
dagent.com. 1 NS ns1.exsbs.net.
Authority
The response has no authority records.
Additional
ns1.exsbs.net. 1 A 63.73.11.2
ns2.exsbs.net. 1 A 63.73.11.3
vns1.dagent.com. 1 A 63.73.11.5
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0