mta01.testgt.net has no NS records.
NS records for this zone are defined at testgt.net.
NS records for this zone are defined at testgt.net.
Question and response
Question
dig mta01.testgt.net. NS
Answer
The response has no answer records.
Authority
testgt.net. 300 SOA ns-cloud-a1.googledomains.com. courrieraffaire.telus.com. 2 21600 3600 259200 300
Additional
. 0 OPT ; payload 512, xrcode 0, version 0, flags 0