Port Forwarding Explained

What is

port

forwarding

? Maybe you've heard of it, but weren't exactly sure what it was or how it worked. Thus, through

port

forwarding

, computers can connect via the Internet to a specific computer or service within a private network. Basically, it makes your computer accessible over the Internet, even if you are behind a router. For example, let's say a friend of yours at home wants to remotely manage their computer at home using a service like Remote Desktop Connection. A Remote Desktop Connection is now a service built into Microsoft Windows that allows you to connect to another computer running Microsoft Windows.

And once you are connected to the remote computer, you will be able to use the computer's programs and files as if you were sitting in front of it. Now your friend is ready to connect to your computer. Therefore, he initiates the connection to the remote desktop and sends the request to its public IP address with a specific port number. Now, a port is not a physical connection, but a logical connection used by programs and services to exchange information. Ports identify these programs and services running on a computer and in this case an external desktop connection is used from port 3389.

So the request with the port number will go over the Internet to your router and, Once it's on your router, your router needs to know where to forward the request for port 3389. Since you haven't set up port forwarding, your friend can't connect to your computer because your router doesn't know what to do with this request. This is where port forwarding comes into play. So we're going to tell our router to forward or forward the requests that come in with port 3389 and send the request here to our computer. To do this, we will log into our router's configuration page by typing the router's internal IP address using a web browser.

So if you're not sure what your router's internal IP address is, simply open a command prompt on a Windows computer, type ipconfig, and press Enter. And the default gateway is the internal IP address of your router. And it's also important to know your computer's IP address, which is here, because we'll enter the IP address on the port forwarding settings page. So, in a web browser, we enter the IP address of the router and now we are on the router configuration page. Depending on the router you are using, the settings page will now be different depending on the router you are using.

I'm using a Cisco Linksys router in this example. Regardless of what router you use, the layout will be a little different. But basically you need to go to port forwarding section to configure port forwarding. So here on a configuration page for port forwarding, we can just enter a name for our application and we can just call it remote desktop, and then we need to port forward for the external connection to the computer. So you type the port number of the remote desktop, which turns out to be 3389, and then you have to point it to the IP address of the computer that your friend wants to access, which is 192.168.1.2 and then we can save our configuration. and now we are done.

So if your friend sends a request with port 3389, the router knows where to forward the request and now the connection is complete. If you are still confused about ports, let's use an illustration to explain what a port is and how it works. Here we then have a telephone with an electronic switchboard that would normally be used in a business. So if someone wants to call this company and say they want to talk to the sales department of this company, they call the company's phone number, along with the sales department's extension. As soon as the call comes in, the phone will answer the call and then verify the extension number and send or forward the call to the corresponding department number.

Let's say someone else calls the company and wants to speak to the support department. Then the call comes in and is received over the phone. Now the phone number has done its job, which is to send the call from outside to the specific company. But once the call with the phone number is received, the phone number is no longer necessary because it has done its job. So all that is needed now is expansion. So the phone will now send the call to the support department due to the matching number. Now it works in a very similar way on a network.

Therefore, in a network, the router is contacted with an IP address and a port number. So the router will now look at the port number and send or forward the request to the internal IP address that the port is configured to. So again, another internet request enters the network and reaches the router. Therefore, the IP address has done its job: carrying the Internet request to the router. Then the IP address is no longer needed because he has already done his job. Therefore, the router will now look at the port number and depending on the port forwarding settings, send the request to the computer with the IP address that the port number is set to.

Therefore, in a network the IP address is similar to a telephone number. And the port number is similar to an extension. The router inserts the phone. And the computers within that network represent different departments. Ports are always associated with an IP address and are identified by a unique number. So regardless of whether you see the port number or not, a port number is always associated with an IP address, because an IP address always has a purpose. And use the port number to determine what the target is. Whether setting up a web page, using an FTP service or using a remote desktop.

It always has a purpose determined by the port number. Because ports are not only associated with an IP address, but they are also always associated with an application or process, such as FTP web pages, email, etc. Port numbers vary from 0 to 65535. But of the 65,000, it is feared to be the most common and the one used daily. For example, like port 80 used for web pages. There are also ports 20 and 21 that are used for File Transfer Protocol or FTP. Or port 443 which is used to configure secure web pages. But these are just a few. In fact, there is a privileged category of ports called known ports, which range from port 0 to port 1023.