ftp.ciberserver.net has no CNAME records.
Question and response
Question
dig ftp.ciberserver.net. NS
Answer
The response has no answer records.
Authority
ciberserver.net. 6206 SOA ns1.ciberserver.com. status.ciberconceito.com. 2025103108 3600 1800 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0