iptable介绍：Iptables默认有三张表（队列），分别是mangle、nat、Filter，mangle表主要用来mangle（中文解释：轧）包，你可以使用mangle匹配来改变包的TOS等特性，mangle表中仅有TOS、TTL、MARK几种操作，nat表用来转换包的源或目标地址，包括DNAT、SNAT和MASQUERADE等类型，filter 表用来过滤数据包，过滤工作主要是在这儿完成的。-iptable Introduction: Iptables has three default table (queue), respectively, mangle, nat, Filter, mangle table is mainly used to mangle (Chinese explanation: rolling) package, you can use the mangle matches the TOS to change the package and other features, mangle table Only TOS, TTL, MARK several operations, nat table is used to convert the packet' s source or destination address, including DNAT, SNAT and MASQUERADE other types, filter table is used to filter packets, filtering work is mainly accomplished here.