Linux® Routing

IP Masquerading

In many cases, you’ll want to use a router to perform IP Masquerading. Typically IP Masquerading is used to connect a private network with “illegal” IP addresses to the outside world. This is particularly true when your location only has one public IP address through a dial-up line, DSL, cable modem, or whatever.

All of the traffic from one or more computers routed through a machine with a direct interface to the Net appears to come solely through that machine. The practical upshot of this, of course, is that a number of computers can share one connection to the Internet. This is cheaper and causes less of a security risk. Assume you have a computer behind your router/firewall with all of your credit card numbers and Aunt Grizzelda’s ...