bts.gblnet.net has no NS records.
NS records for this zone are defined at gblnet.net.
NS records for this zone are defined at gblnet.net.
Question and response
Question
dig bts.gblnet.net. NS
Answer
The response has no answer records.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0