def close(self):
		'''关闭与数据库的连接'''
		if VERBOSE:
			print 'Database connection CLOSE.'
		self.conn.close()
def remove_vpp_config(self):
        self._test.vapi.ip_path_mtu_update(pmtu={'nh': self.nh,
                                                 'table_id': self.table_id,
                                                 'path_mtu': 0})