xen.datof.com has no CNAME records.
Question and response
Question
dig xen.datof.com. NS
Answer
The response has no answer records.
Authority
datof.com. 3229 SOA ns1.datof.com. kazsaa.i.kazsaa.hu. 2026013101 3600 1800 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0