| So first, here are a couple of things that you can do | | | | computer has 65536 ports (numbered 0 to 65535). |
| after you finish this section.- You can configure | | | | When a computer attempts to talk to another |
| BitTorrent to give you excellent speeds- You can | | | | computer, the attempt is always initiated along with a |
| configure your computer to play multiplayer games | | | | port number.Forwarding Ports Lets assume that a |
| over the internet- You can setup your computer as a | | | | computer on the Internet needs to initiate a connection |
| terminal server (for remote desktop connections)- and | | | | to a specific software on your computer. The |
| many many more cool stuff!!This tutorial consists of 2 | | | | software in discussion uses port 12345. For simplicity, |
| sections1. Understanding Port Forwarding2. | | | | we will call the initiating computer as ClientX, and your |
| Implementing Port Forwarding on common | | | | computer as the ServerX. As we discussed earlier, |
| routersWhat is portforwarding?In one sentence, | | | | clientX only sees (and knows) the external IP address |
| portforwarding makes the internet see your computer | | | | i.e. the IP address of your router. It tries to initiate a |
| as if it were directly connected rather than being | | | | connection to that IP address with the port number |
| connected though a router. For the same reason, if | | | | 12345. However, your router recieves this request, and |
| you dont have a router, and your computer IS directly | | | | sees 4 computers in your house connected to the |
| connected to the Internet, then you wont need this | | | | router. The router is not able to figure which computer |
| tutorial.A little explanation: When a computer is | | | | the connection from ClientX was intended for! So it |
| connected to the internet, it is assigned a unique | | | | simply drops the connection.Port forwarding is a setting |
| address called the IP address. This enables other | | | | in the router which you can change to prevent this |
| computers on the internet to communicate with it and | | | | from happening. By doing this, you can tell the router |
| send packets to it and so on... An IP address has the | | | | that any connections for port 12345 has to be |
| format ###.###.###.###. It looks like four sets of | | | | forwarded to ServerX. Now when the router recieves |
| numbers, separated by a dot. Each set can have a | | | | a request for a connection on port 12345, it checks its |
| value between 0 and 255.Usually the internet service | | | | table and sees your entry saying that all connections |
| provider is the guy who assigns you an IP address for | | | | for port12345 have to be forwarded to serverX. |
| your connection. However, he gives you only ONE ip | | | | Hence it routes the connection accordingly!Here we'll |
| address and this gets assigned to the cable/dsl | | | | see how to do portforwarding on most routers. |
| modem at your house. If you directly connect your | | | | Scenario : Lets say you need to forward port 6889 to |
| computer to the cable/dsl modem, you are using this IP | | | | a computer whose Internal IP is 192.168.1.10.Step 1: Find |
| address to communicate with other computers on the | | | | your gateway IP address. To get this, in windows, |
| internet. However, you can connect only one computer | | | | select Start > Run. Type in "CMD" and hit enter. Inside |
| to the cable modem at any given time. So you go to | | | | the command window, type "ipconfig" and hit enter. |
| the nearest store and buy a router.Role of the router | | | | The screen will show you the default gateway. Note |
| A router connects to the cable/dsl modem and splits | | | | this down.Step 2: Open Internet explorer. Enter your |
| the one internet connection into multiple connections so | | | | gateway from Step 1 in the address bar, and hit enter. |
| all the computers in your house can enjoy internet | | | | A popup window will ask you to authenticate into your |
| connectivity simultaneously. Once you get the router, | | | | router with a username and password. Enter the |
| you connect the router to your cable/dsl modem, and | | | | username and password. If you dont remember, try |
| all your computers to the router.Internal and External IP | | | | the default ones below:Linksys router : Default |
| addresses Once you start using a router, the IP | | | | username "" password "admin" |
| address given by your internet service provider gets | | | | NetGear router : Default username "admin" |
| assigned to the router. This IP address is called the | | | | password"password" |
| External IP address, as it is part of the external | | | | Belkin router : Default username "" password"" |
| network between your router and the Internet. The | | | | D-Link router : Default username "admin" password"" |
| router in turn assigns new IP addresses to the | | | | Gateway router : Default username "admin" |
| computers connected to it. These addresses are a | | | | password"admin" |
| part of your Internal Network, and are called Internal IP | | | | If you cant remember the password, post it on the |
| addresses. By set laws, an Internal IP address may | | | | forum at and someone will help you!Step 3:For Belkin |
| start with the numbers 10,128, or 192. All the other | | | | routers, select virtual servers from the left menu. Enter |
| combinations are used for external addressing.For | | | | something for description. Type "6889" or the required |
| example, my external IP address is 68.36.145.156. This | | | | port number in both fields for inbound port. Do the |
| IP address is assigned to my router. I have two | | | | same for the Private port fields too. Select the |
| computers connected to the router, and they have the | | | | connection type from the drop down. If you dont know |
| IP addresses 192.168.0.10 and 192.168.0.11. These are my | | | | what you need, try UDP. If that doesnt work, come |
| internal addresses.The Port conceptEven when you | | | | back and try TCP. In the private IP address field, enter |
| use a router to connect many machines to the internet, | | | | the computer to which you need the connection |
| other computers on the internet see one single | | | | forwarded. In our case, this is 192.168.1.10Linksys |
| machine with the external IP address of the router. | | | | routers, select "Application and Gaming" from the top |
| They dont know that a router is sitting inside your | | | | menu, and the select 'portrange forwarding' from the |
| house and splitting the external address into many | | | | submenu. In another family of linksys routers, you can |
| internal IP addresses. They can only make a | | | | find 'Forwarding' section under 'advanced' tab of main |
| connection to your router, and your router decides | | | | setup page. Rest of the process is the same as that |
| how to route the connection and to which internal | | | | for Belkin routers above.Netgear routers, you'll find 'Port |
| computer to route it to.IP addresses are further divided | | | | Forwarding' under the 'Advanced' table in the main |
| into channels called ports. This permits one IP address | | | | page. The rest of the steps are same as above.Step |
| to be shared by multiple programs at the same time, | | | | 4:Save the setting and restart the router. Your port |
| each using a different port. By standard every | | | | forwarding is complete. |