Python 2.5.2 (r252:60911, Jul 31 2008, 17:28:52) 
[GCC 4.2.3 (Ubuntu 4.2.3-2ubuntu7)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import ldap
>>> ldap.set_option(ldap.OPT_X_TLS_CACERTFILE, '/etc/ssl/certs')
>>> conn = ldap.initialize('<hostname>:3268')
>>> conn.start_tls_s()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.5/site-packages/ldap/ldapobject.py", line 528, in start_tls_s
    return self._ldap_call(self._l.start_tls_s)
  File "/usr/lib/python2.5/site-packages/ldap/ldapobject.py", line 97, in _ldap_call
    result = func(*args,**kwargs)
ldap.CONNECT_ERROR: {'desc': 'Connect error'}