DBMS_LDAP: ORA-24247: network access denied by access control list (ACL) : Oracle

BEGIN
   DBMS_NETWORK_ACL_ADMIN.CREATE_ACL (
    acl          => 'ldap_access.xml',
    description  => 'Permissions to access LDAP servers.',
    principal    => 'FDC_EXEC',
    is_grant     => TRUE,
    privilege    => 'connect');
   COMMIT;
END;

BEGIN
   DBMS_NETWORK_ACL_ADMIN.ASSIGN_ACL (
    acl          => 'ldap_access.xml',
    host         => '10.1.200.20',
    lower_port   => 389,
    upper_port   => 389
    );
   COMMIT;
END;

SELECT * FROM DBA_NETWORK_ACLS;
SELECT * FROM DBA_NETWORK_ACL_PRIVILEGES;

begin
      DBMS_NETWORK_ACL_ADMIN.ADD_PRIVILEGE('/sys/acls/ldap_access.xml',
     'NEWUSER', TRUE, 'connect');
     COMMIT;
end;

begin
      DBMS_NETWORK_ACL_ADMIN.DELETE_PRIVILEGE('/sys/acls/ldap_access.xml', 
     'NEWUSER', TRUE, 'connect');
     COMMIT;
end;