cluster2.convio.net has no NS records.
NS records for this zone are defined at convio.net.
NS records for this zone are defined at convio.net.
Question and response
Question
dig cluster2.convio.net. NS
Answer
The response has no answer records.
Authority
convio.net. 3600 SOA dns1.convio.net. netadmin.convio.com. 2026021901 1800 300 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0