mx.hi-load.biz has no NS records.
NS records for this zone are defined at hi-load.biz.
NS records for this zone are defined at hi-load.biz.
Question and response
Question
dig mx.hi-load.biz. NS
Answer
The response has no answer records.
Authority
hi-load.biz. 600 SOA ns14.strongns.net. root.strongns.net. 1499617864 1800 1200 259200 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0