I want to use memberof overlay but I do not have a clue on how to even look at it.

[Eliezer Croitoru <eliezer@ngtech.co.il>]

I want to use memberof overlay but I do not have a clue on how to even 
look at it.
I have tried to use this:
http://www.schenkels.nl/2013/03/how-to-setup-openldap-with-memberof-overlay-ubuntu-12-04/

which kind of worked and it has added something to my database.
Now I have tried to run some search but either I am doing something 
wrong or the memberof is not loaded.

So first, how do check that it is loaded?
I was thinking about :
ldapsearch -x -H ldap:/// -b cn=module

but again I am unsure since it won't give results.
I am trying to use memberof for squid to match a group membership.
Any hints? directions to understand?

I understand the basics of LDAP but this is something above basic LDAP.

Thanks,
Eliezer