Apex domains cannot have CNAME records.
Question and response
Question
dig es.tdatacenter.com. NS
Answer
es.tdatacenter.com. 5 NS edns02.es.tdatacenter.com.
es.tdatacenter.com. 5 NS edns01.es.tdatacenter.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0