How To: Port Forwarding for Newbies

Port Forwarding for Newbies

Port Forwarding for Newbies

I have came across a lot of members on the forum that didn't have a clear idea of what port forwarding is and what it does. So...Let's get started...

Your router is blocking outside traffic from coming inside the network for security reasons (Kind of, like, a firewall level), unless a PC on the network wants it.

Why It's There

Imagine a celebrity.His bodyguard won't let you in his house for no reason, but, if the celebrity had ordered pizza though and you were the delivery guy , the bodyguard would be happy to have get you in :). That's what the router's firewall is and that's where port forwarding comes in. Port forward lets you choose a port of the router that's going to be open the whole time (or for a specified amount of time, if the router's settings allow you to) and outside traffic would be always allowed through that port.

How It Works

Now, again, imagine an airport. The outside traffic has reached the terminal from that specific port that you opened, but still needs to go to its target -the flight 192.168.1.6 (A computer in the network)-. The airplane has still a LOT of ports (doors) (65.535 to be specific) and it need to go to a certain port of that plane. Now, you have specified that the traffic from port number X will enter the plane from port Y. The outside traffic that had previously entered the terminal, happened to have entered through that port (Port X), thus it boards the plane from port Y. See?! Easy! :P (In sort terms, you Forward a port from the router to your PC/Phone/Smart Fridge e.t.c.)

Rules of Port Forwarding

1)The Port X cannot be a higher number from Port Y (CORRECT--> PortX=56 & PortY=58 , WRONG---> PortX=345 & PortY=3).

2)The Port X should be a number close to that of the Port Y (PortX=56, PortY=58).

3) Port X can be the same as Port Y

4) Ports n.80,8080,20,21,23,25 are usualy used by the webserver of your router, so try to avoid using those...

5) NO DUPLICATE ROUTER-SIDE PORTS! ex. Rule1(PortX goes to PortY) Rule2(PortX goes to PortE) but the opposite, Rule1(PortX goes to PortY) Rule2(PortB goes to PortY), can happen.

Real World Example

Now let's say you have a web server that runs on your computer on port 80. You can access the Server only from devices from inside the network because the router blocks outside traffic. You port-forward port number 60 on your router to port 80 on you PC. Now you can access your lovely Web Server from (public ip):60!!! :D

Technical part

Now the technical part of port forwarding is quite tricky, because there are millions of routers out there with different configuration page layouts. Thus, sites like PortForward.com exist () that offer guides for almost any router out there! (WARNING!: You do not need to pay in order to see the guides! When that screen pops-up, click the "Close" button on the top-right corner)

P.S. Now remember, each device inside the network has the SAME public IP address but NOT the same local IP address , so, your router doesn't only block outside traffic for your security reasons but it also doesn't know to which device the outside traffic is heading.

Thanks for reading
-DONFN

12 Comments

Nice article.Looking forward for your next post.

Thanks :D

hey,
tell me how to port forward for VmWare workstation 9 ??
please post an Artical .

HEy it is not working my ports are still closed ... what to do now ?

Well, what i can say to you, is, that you need to forward the ports on your router, not on your VMWare. Opening on the router, anything you use on the specifical internal IP gonna be fowarded to the port you wanted to.

That means only to port forward the external router /wingle and connect the vm in bridged mode and thats all???????

First, a great information by DONFN I have couple of questions related to portforward using android phone, I am security enthusiastic from India and I like to do hands on with technical stuff, if you have any idea on bellow mentioned points, it would be a great help.

a. can I use android phone (using wifi or cable) to port forward
b. can I use USB dongle to portfoward

Hey,
Sorry for responding late!

Actually port forwarding can be done through the router's web interface or the "UPNP" protocol... If you are connected to a WiFi network though your android device, fire up "Fing" (can be found on Google Play Store) and find the router. Then, run a service scan on the router and connect to it via http (or https), the password is usually written on the bottom of the device. After that, you can pretty much find more info on how you can port forward on google -since the procedure is different on every brand/model...Now, i don't know how port forwarding can be done though UPNP at a mobile device, I don't know any app that does that...You can google it anyway though...Thanks for asking!!

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