ns1.add-online.com has no NS records.
NS records for this zone are defined at add-online.com.
NS records for this zone are defined at add-online.com.
Question and response
Question
dig ns1.add-online.com. NS
Answer
The response has no answer records.
Authority
add-online.com. 300 SOA ns1.add-online.com. hostmaster.addonline.fr. 2012112807 86400 21600 2419200 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0