然后它用它自己注册的IP地址替换发送来的数据包的IP地址，并将端口号替换为该数据包的源计算机信息条目在表中的相应位置号。

It then replaces the IP address with its own registered IP address and the port number corresponding to the location of the entry for that packet's source computer in the table.

youdao

因为每个通信都包含源ip地址和源端口，所以主机能够区分这三个不同的连接。

Because every communication contains the source IP address and source port, the mainframe can distinguish between those three different connections.

youdao

缺省源匹配与所有 IP 地址匹配。

The default source match matches all IP addresses.

youdao