iptables HOWTO（中文版）[3]

指定使用的目的端口或端口范围：不指定的话，目标端口不会被修改。只能用于指定了-p tcp 或 -p udp的规则。


诊断
不同的错误信息会打印成标准错误：退出代码0表示正确。类似于不对的或者滥用的命令 行参数错误会返回错误代码2，其他错误返回代码为1。


臭虫
检查还未完成。


COMPATIBILITY WITH IPCHAINS
与ipchains的兼容性

This iptables is very similar to ipchains by Rusty Russell. The main difference
is that the chains INPUT and OUTPUT are only traversed for packets coming into
the local host and originating from the local host respectively. Hence every
pack only passes through one of the three chains; previously a forwarded packet
would pass through all three. The other main difference is that -I refers to
input interface; -o refers to the output interface, and both are available for
packets entering the FORWARD chain. iptables is a pure packet filter when using
the default filter' table, with optional extension modules. This should
simplify much of the previous confusion over the combination of IP masquerading
and packet filtering seen previously. So the following options are handled