Openldap Replication don't run after configuring I'm practicing OpenLDAP replication with 2 Centos 6.9 64bit virtual machines. 

The setting-up process was fine, but after I insert data into the master server, nothing happens in the slave.

MASTER SETTING

slapd.conf

overlay syncprov
syncprov-checkpoint 100 10
syncprov-sessionlog 100
updatedn "cn=Manager,dc=example,dc=com"
updateref ldap://192.168.1.11:389 


SLAVE SETTING

slapd.conf

   syncrepl     rid=2
                provider=ldap://192.168.1.10
                type=refreshOnly
                interval=00:00:00:01
                searchbase="dc=example,dc=com"
                filter="(objectClass=*)"
                attrs="*"
                scope=sub
                schemachecking=off
                updatedn="cn=manager,dc=example,dc=com"
                bindmethod=simple
                binddn="cn=manager,dc=example,dc=com"
                credentials=secret
updateref       ldap://192.168.1.10


I'm using OpenLDAP 2.4.21,  BerkeleyDB-4.8.
The directives updatedn and updateref do not make sense at the provider (master).

You probably also want type=refreshAndPersist for continous replication. Setting interval= to one second would not work well with many entries in the DB.

Make sure that attributes entryUUID and entryCSN are indexed at the provider.

Also note that OpenLDAP 2.4.21 is really ancient release. During the last 9 years many things were fixed in OpenLDAP, especially related to replication.

I'd recommend to use the RPMs built by LDAP Toolbox project. They provide YUM repos also for RHEL/CentOS 6.

See also: OpenLDAP Admin Guide -- Replication