int.ivcert.net has no CNAME records.
Question and response
Question
dig int.ivcert.net. NS
Answer
The response has no answer records.
Authority
ivcert.net. 747 SOA ns1.ivnosys.net. sistemas.ivnosys.com. 1770886836 7200 1800 1209600 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0