ns2.coeficiente.net.mx has no CNAME records.
Question and response
Question
dig ns2.coeficiente.net.mx. NS
Answer
The response has no answer records.
Authority
coeficiente.net.mx. 6970 SOA ns1.teknios.com. datacenter.coeficiente.mx. 2026021201 3600 1800 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0