The ldap server that ships with the Gluu Server is the user and config store for the IDP, so it needs to be protected. We don't want it used for anything except the Gluu Server database. It is not listening on any interface other then localhost.
You can use ssh tunnel to connect to the Gluu ldap server from another host.
From your ubuntu box, try something like
$ ssh -L 1636:127.0.0.1:1636 root@myhost
And then run your client and connect LDAPS to localhost:1636
BTW, if you want a plain vanilla OpenDJ, we are collaborating in this project: