mx.i.bitbit.net has no NS records.
NS records for this zone are defined at i.bitbit.net.
NS records for this zone are defined at i.bitbit.net.
Question and response
Question
dig mx.i.bitbit.net. NS
Answer
The response has no answer records.
Authority
i.bitbit.net. 3600 SOA ns-foo.i.bitbit.net. hostmaster.redpill-linpro.com. 2019045448 10800 3600 2419200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0