mx1.hctc.net has no NS records.
NS records for this zone are defined at hctc.net.
NS records for this zone are defined at hctc.net.
Question and response
Question
dig mx1.hctc.net. NS
Answer
The response has no answer records.
Authority
hctc.net. 86400 SOA infobloxcmft-gmc.hctc.coop. hostmaster.hctc.net. 2015030812 10800 3600 604800 86400
Additional
. 0 OPT ; payload 1220, xrcode 0, version 0, flags 0