Configure the /etc/ldap.conf file as follows:

ldap_version 3
base dc=example,dc=com
nss_base_passwd dc=example,dc=com?sub
nss_base_group dc=example,dc=com?sub
nss_schema rfc2307bis
nss_map_objectclass shadowAccount posixAccount
nss_map_attribute uniqueMember member
nss_initgroups_ignoreusers root,dirsrv
nss_reconnect_maxsleeptime 8
nss_reconnect_sleeptime 1
bind_timelimit 5
timelimit 15
nss_srv_domain example.com
uri ldap://ipaserver.example.com