mail.lasvegas.net has no NS records.
NS records for this zone are defined at lasvegas.net.
NS records for this zone are defined at lasvegas.net.
Question and response
Question
dig mail.lasvegas.net. NS
Answer
The response has no answer records.
Authority
lasvegas.net. 3600 SOA gate.lasvegas.net. postmaster.lasvegas.net. 2002020684 7200 3600 1209600 7200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0