In this recipe, we will use BackTrack to perform port redirection; also known as port forwarding or port mapping. Port redirection involves the process of accepting a packet destined for one port, say port 80, and redirecting its traffic to a different port such as 8080. The benefits of being able to perform this type of attack are endless because with it you can redirect secure ports to unsecure ports, redirect traffic to a specific port on a specific device, and so on.
Let's begin the port redirection/forwarding process.
Sudo echo 1 >> /proc/sys/net/ipv4/ip_forward