ns2.constant.com has no NS records.
NS records for this zone are defined at constant.com.
NS records for this zone are defined at constant.com.
Question and response
Question
dig ns2.constant.com. NS
Answer
The response has no answer records.
Authority
constant.com. 3600 SOA ns1.choopadns.com. abuse.choopa.com. 0 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0