dns1.nexen.net has no NS records.
NS records for this zone are defined at nexen.net.
NS records for this zone are defined at nexen.net.
Question and response
Question
dig dns1.nexen.net. NS
Answer
The response has no answer records.
Authority
nexen.net. 86400 SOA dns1.nexen.net. postmaster.nexen.net. 2026032701 28800 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0