I'm sorry but is it just "nameserver ip" (or) "ebox ip" in the other /etc/resolv.conf.
The same entry as in the resolv.conf on the server.
Domain is already registered and has a DNS entry
If the domain is registered, and the dns entry is made, then your server has a public ip, right?
If not, the name will resolve to the public ip from the router.
If you want to use nslookup, you need to give the whole domainname mydomain.com
If this doesn't work, it's possible DNS isn't propagated yet.