BetaLog

作者:zyqin http://www.betalog.cn

In home networking, port forwarding, also called port mapping or punch-through, enables you to create a permanent translation entry that maps a protocol port on your gateway machine to an IP address and protocol port on your private LAN. It's a transparent process, meaning network clients cannot see that port forwarding is being done. This process enables you to run a public Internet service on a machine that is otherwise hidden from the Internet by your gateway. Port forwarding may also be used to aggregate traffic from an application that uses several ports for transactions and consolidate it into one port for reporting the total traffic identified with that application.

在家庭网中，port forwarding又成为端口映射或punch-through，这种技术可以让你创建一个永久的映射关系，使你的内网的一个IP地址的协议端口和网关上的一个协议端口相对应。对于客户端来说，端口映射是透明的。

你的内部网络的一台客户机可以在互联网上提供公共服务，同时你的客户端隐藏在网关的背后，外部用户无法知道你客户端的真是情况。

Port forwarding也可以通过把多个端口映射到同一个端口，以便于流量统计。