nabil.ns.lb has no CNAME records.
Question and response
Question
dig nabil.ns.lb. NS
Answer
The response has no answer records.
Authority
lb. 81719 SOA b.ns.lb. hostmaster.psg.com. 1772541555 86400 3600 2592000 172800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0