Aug 20, 2013

Port Forwarding

What is Port Forwarding

In General Sense:

I'll first explain port forwarding in a general sense. Imagine your computer is a human and imagine one port as the mouth, and the data is the food. You can close or open your mouth (port) to eat that food (data) and transfer that food into another location in your body. Same goes for your ear (another port) where it recieves sound, and so on.
The use of port forwarding is to be able to transmit data from an outside world to your computer. This allows an external user to communicate with your computer via a specified port number. Normally you do not want to do this because it can leave your computer vulnerable to attacks but in special cases that you do need this, it will prove very useful.

In Technical sense:

Port forwarding or Port Mapping commonly refers to the change of destination address and/or port on the packet with subsequent regular routing in a network address translator gateway
 to reach a host within a masqueraded, typically private, network based on the port number on which it was received from the originating host. It may also refer to replaying the packet or stream through a secondary socket (e.g. like rinetd) to reach its intended destination.
The technique is used to permit communications by external hosts with services provided within a private local area network (LAN).


Port forwarding allows remote computers (e.g., public machines on the Internet) to connect to a specific computer within a private LAN.
Port forwarding can also be used within a single machine.
Port forwarding is necessary for a standalone computer if any of the following conditions are true:

*   The computer is using a shared IP address.
*   Internet Connection Sharing is enabled.
*   A router is being used with network address translation (NAT) enabled.
How is Port Forwarding Configured
Simple Port Forwarding
Simple Port Forwarding is a tool that makes it easier to manage the port forwarding settings in your router. You can add new port configurations manually or select from a range of pre-configured ports for many popular applications and apply the settings directly to your router configuration. The program interfaces with the web interface of your router and basically automates the process of navigating to the correct page and entering the values. It is compatible with a wide range of routers, including most Netgear, D-Link and Linksys models as well as some other manufacturers. Simple Port Forwarding also includes additional features that allows you to set a static IP address, test your port forwarding settings, manage Windows Firewall port exceptions and access to online help and guides.