Install ldap

apt-get install libnss-ldap

Configure ldap access

Configure /etc/libnss-ldap.conf | /etc/pam_ldap.conf to reflect to correct values to at least:

base dc=skarta,dc=net
uri ldap://ldap.skarta.net/

Change /etc/nsswitch.conf from:

[ ... ]
passwd:         compat
group:          compat
shadow:         compat

hosts:          files dns
[ ... ]

to

[ ... ]
passwd:         compat ldap
group:          compat ldap
shadow:         compat ldap

hosts:          files dns ldap
[ ... ]

/etc/init.d/nscd restart

getent passwd

Should show all your ldap users.