Hello On Wed, Jan 2, 2013 at 7:08 PM, Ali Jawad <ali.jawad(a)splendor.net&gt; wrote: Are you using SSSD or NSLCD to configure Centos6 as a LDAP client, If you are using SSSD, You need to have TLS enabled on your LDAP server. Try this. Install nss-pam-ldapd & pam_ldap # yum install nss-pam-ldapd pam_ldap Configure nslcd Using GUI. Authconfig will try to use sssd by default, in order to configure nslcd, enable FORCELEGACY option in authconfig as shown below. Edit /etc/sysconfig/authconfig, change "FORCELEGACY" option to "yes" FORCELEGACY=yes # authconfig --enableldap --enableldapauth --ldapserver="ldap01.example.com" --ldapbasedn="dc=example,dc=com" --enableforcelegacy --update Regards Arpit Tolani