ns1.exoscale.net has no NS records.
NS records for this zone are defined at exoscale.net.
NS records for this zone are defined at exoscale.net.
Question and response
Question
dig ns1.exoscale.net. NS
Answer
The response has no answer records.
Authority
exoscale.net. 300 SOA ns2.exoscale.net. hostmaster.exoscale.net. 1397072600 7200 1800 2419200 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0