Can be called when an interface is put in service.
        FIXME: not currently used; more needs to be done to
        correctly put a new intf into service.

def intf_up(self, interface):
        '''
        Can be called when an interface is put in service.
        FIXME: not currently used; more needs to be done to
        correctly put a new intf into service.
        '''
        if interface.name not in self._devinfo:
            self._devinfo[interface.name] = interface
            if self._devupdown_callback:
                self._devupdown_callback(interface, 'up')
        else:
            raise ValueError("Interface already registered")