aggr931a-12.dfw1.rackspace.net has no NS records.
NS records for this zone are defined at dfw1.rackspace.net.
NS records for this zone are defined at dfw1.rackspace.net.
Question and response
Question
dig aggr931a-12.dfw1.rackspace.net. NS
Answer
The response has no answer records.
Authority
dfw1.rackspace.net. 300 SOA ns.rackspace.com. hostmaster.rackspace.com. 1770734274 3600 300 1814400 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0