ns1.slovanet.net has no CNAME records.
Question and response
Question
dig ns1.slovanet.net. NS
Answer
The response has no answer records.
Authority
slovanet.net. 9374 SOA ns.slovanet.net. dns.slovanet.net. 2026020502 7200 3600 604800 10800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0