ns4.he.net has no NS records.
NS records for this zone are defined at he.net.
NS records for this zone are defined at he.net.
Question and response
Question
dig ns4.he.net. NS
Answer
The response has no answer records.
Authority
he.net. 86400 SOA ns1.he.net. hostmaster.he.net. 202603050 10800 1800 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0