syncrepl simple bind

[S.A.]

Hello,

For syncrepl to work do we need to enable the sasl? I had the sasl
disabled and configured to replicate using simple bindmethod, with
the following config:
syncrepl        rid=001
                provider=ldap://ldap2.example.com
                type=refreshAndPersist
                retry="5 5 300 +"
                searchbase="o=tld"
                bindmethod=simple
                binddn="uid=admin,ou=users,o=tld"
                credentials=password
                schemachecking=on

but I get the following error:

slap_client_connect: URI=ldap://ldap2.example.com
DN="uid=admin,ou=users,o=tld" ldap_sasl_bind_s failed (-1)

However, I can bind and search entries both in cn=config and o=tld
from command line using the above binddn and credentials. 

Thanks