def __init__(self, name, host='127.0.0.1', port=27017):
        self.name = name
        self.host = host
        self.port = port
def modify(self, pmtu):
        self.pmtu = pmtu
        self._test.vapi.ip_path_mtu_update(pmtu={'nh': self.nh,
                                                 'table_id': self.table_id,
                                                 'path_mtu': self.pmtu})
        return self