用在LINUX下，计算网络中的流量，包括 TCP 、UDP 、ICMP等等，只要经过了网卡的，全部都计算在内，先需要配置整个网络。-used in Linux, the calculation of the network flow, including TCP, UDP, ICMP, and so on. After as long as the card and are taken into account, first need to configure the entire networ