Connect to the device.

def connect(self, ctrl):
        """Connect to the device."""
        if self.prompt:
            self.prompt_re = self.driver.make_dynamic_prompt(self.prompt)
        else:
            self.prompt_re = self.driver.prompt_re

        self.ctrl = ctrl
        if self.protocol.connect(self.driver):
            if self.protocol.authenticate(self.driver):
                self.ctrl.try_read_prompt(1)
                if not self.prompt:
                    self.prompt = self.ctrl.detect_prompt()

                if self.is_target:
                    self.update_config_mode()
                    if self.mode is not None and self.mode != 'global':
                        self.last_error_msg = "Device is not in global mode. Disconnected."
                        self.chain.disconnect()
                        return False

                self.prompt_re = self.driver.make_dynamic_prompt(self.prompt)
                self.connected = True

                if self.is_target is False:
                    if self.os_version is None:
                        self.update_os_version()

                    self.update_hostname()
                else:
                    self._connected_to_target()
                return True

        else:
            self.connected = False
            return False