LDAP server for Entourage X

I am trying to set up Entourage X in a Windows 2000/Exchange 2000 environment.

Entourage requires the name of an LDAP server, and a search base. I was assuming that the Win2K domain controllers (or Exchange server?) could be used as the LDAP server, but as a connection cannot be made this does not appear to be the case.

Can anyone confirm the requirements for an LDAP Server? (Better still setup for Entourage X)