主机地址

• The packet filter normally does not look within the contents of a tcp or udp packet , unless specifically directed to do so . the application requires that the protocol contain the appropriate address information for the host or it will fail to work
  这些应用可能会将网络或主机地址信息嵌入到tcp或udp包里，但包过滤器一般不深入探究这些包中的内容。