>>> conn.bind()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.5/site-packages/ldap3/core/connection.py", line 413, in bind
    self.open(read_server_info=False)
  File "/usr/lib/python3.5/site-packages/ldap3/strategy/sync.py", line 54, in open
    BaseStrategy.open(self, reset_usage, read_server_info)
  File "/usr/lib/python3.5/site-packages/ldap3/strategy/base.py", line 140, in open
    raise LDAPSocketOpenError('invalid server address')
ldap3.core.exceptions.LDAPSocketOpenError: invalid server address