'Open the tunnel.'

def _bindSocket(self):

    log.msg(format='%(protocol)s    starting    on    %(interface)s', protocol=self.protocol.__class__, interface=self.interface)
    try:
        (fileno, interface) = self._openTunnel(self.interface, (self._mode | TunnelFlags.IFF_NO_PI))
    except (IOError, OSError) as e:
        raise error.CannotListenError(None, self.interface, e)
    self.interface = interface
    self._fileno = fileno
    self.connected = 1
