ftp3.nska.net has no CNAME records.
Question and response
Question
dig ftp3.nska.net. NS
Answer
The response has no answer records.
Authority
nska.net. 3455 SOA dns1.nska.net. www.nska.net. 2026011211 14400 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0