Apex domains cannot have CNAME records.
Question and response
Question
dig siidc.com. NS
Answer
siidc.com. 4 NS ns2.siidc.net.
siidc.com. 4 NS ns1.siidc.net.
Authority
The response has no authority records.
Additional
ns1.siidc.net. 4 A 61.78.63.231
ns2.siidc.net. 4 A 210.112.124.126
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0