I have been setting up a LDAP server using ubuntu 11.04 and the guides around the Internet. This seems to go reasonable well.

I used the documentation found HERE

On the client you need to use three simple comands that are issued from root or a user that has sudo su privileges.

sudo apt-get install libnss-ldap

sudo auth-client-config -t nss -p lac_ldap

 sudo pam-auth-update

After setting up the ldap client I found two issues, the symptoms are:

1. unable to login as a ldap only user on the system
2. unable to change passwd of a ldap only user

The first one is easily solved edit the file /etc/ldap/ldap.conf and uncomment the host statement and make sure it has the ip address of your ldap server.

The second issue was a little harder to track down, when you have logged in as a ldap user and type passwd to change the users password you see something like:

$ passwd

Enter login(LDAP) password:

passwd: Authentication information cannot be recovered

passwd: password unchanged

The way around this is to logon with a user that has root privelidges and type

sudo apt-get install libpam-cracklib

After this logoff and try logging in with your ldap user and now when you try to change the passwd this should all work nicely.

Hope this helps!