ns2.superdnsserver.net has no NS records.
NS records for this zone are defined at superdnsserver.net.
NS records for this zone are defined at superdnsserver.net.
Question and response
Question
dig ns2.superdnsserver.net. NS
Answer
The response has no answer records.
Authority
superdnsserver.net. 900 SOA ns1.superdnsserver.net. hostmaster.superhosting.bg. 2013076248 3600 600 2419200 900
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0