_dmarc.as7600.net has no NS records.
NS records for this zone are defined at as7600.net.
NS records for this zone are defined at as7600.net.
Question and response
Question
dig _dmarc.as7600.net. NS
Answer
The response has no answer records.
Authority
as7600.net. 3600 SOA ns1.as7600.net. hostmaster.as7600.net. 1504178461 10800 3600 604800 38400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0