mx.kornet.net has no NS records.
NS records for this zone are defined at kornet.net.
NS records for this zone are defined at kornet.net.
Question and response
Question
dig mx.kornet.net. NS
Answer
The response has no answer records.
Authority
kornet.net. 43200 SOA ns.kornet.net. domain.ns.kornet.net. 2026010701 43200 3600 604800 43200
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0