Internal ports vs. external – What is the connection between these ports?

Do you have a router that features port forwarding? If yes, you have to know the different ports that you should use toset up port forwarding correctly. Ports are classified into two main categories, mainly internal and external.

What makes internal ports different from external ports? The external port represents the port the outside device tries to connect to while the internal port is the port that is open on the local device.

Introduction to the port forwarding technique

To understand the difference between these ports, you should first learn what port forwarding is all about. This is a straightforward technique that you can apply in your router. The router acts as an intermediary between the internet and your device. It ensures that the data that goes out and comes in gets appropriately directed. This device also keeps on any harmful traffic while at the same time, opening ports to allow useful traffic like games as well as file-sharing programs.

Port forwarding involves a device transmitting the incoming traffic from a particular port to the same port on an internal network node. For this to happen, an external source network has to connect to the internal source node, which connects to an internal private LAN. Some people also call this technique port tunneling or mapping. You can, for instance, allow an external device such as the PlayStation network to an internal device such as PS4. This technique lets you guide your router on where it should forward packets designed for the PS4.

Find out why you should forward ports

Though most of the routers can manage a lot of functions automatically, for some applications, you have to forward a port to them manually. Specific applications make use of NAT to set ports and do the configuration on your behalf. These applications may not need manual configuration.

In a network, data has to be transmitted from a single location to the next after it has been broken down into different packets. The process of breaking down the data facilitates easy transportation. Opening and forwarding ports in your firewall enable you to run a server on your PC or engage in an online game. Forwarding ports can help you access LANs remotely via the internet. The process works through the use of both internal and external ports.

If you like online gaming, then you need to configure port forwarding on your router. Some of the ports have precise applications, while others are not assigned a specific use. You can use such ports for anything. Ports are used through Transmission control protocol (TCP) and User Diagram Protocol (UDP).

Before you try forwarding ports, you should understand that this method is not very secure. By keeping ports open, you expose your network to external threats. You can, however, reduce the risks of port forwarding by updating the connected application. If you run a business and would like to allow incoming connections so that you can operate well, you should consider implementing port forwarding. 

What are the differences between internal and external ports?

Internal ports
External ports
Internal interface
External interface
Handles LAN requests to different resources
It manages all requests from users

Internal ports versus external- How do they compare?

Though these ports work together, they have some differences. Internal ports manage things such as file and web browsing, while external ports manage all requests from users. External ports are mapped to internal ports for port forwarding to take place. Focusing on both ports can help you enhance the connection when you want to do certain things.

Internal ports vs. external- A comparison overview

Internal ports

This is sometimes referred to as an internal interface. It is designed to manage LAN requests to different resources, listen for web browsing, outbound mail requests, authentication, and file browsing. On your home network, your router uses Network address translation. This enables an internal device to share one external IP4 address. The NAT router maps an internal port and internal IP address to the external port and External IP address.

During port forwarding, you should find out how you can configure the internal port settings. Start by selecting device manager in the navigation section. Click on the device tab then double click the section labeled secure access device. Proceed to the configuration tab, then choose system. This will guide you to network settings then internal port tab.

From here, you can modify your settings based on your preferences. You have to provide useful information such as the IP address, DNS server, MTU settings, and gateway. Complete the process by saving the changes.

External ports

Also called the eternal interface, this port manages all the requests from users. For port forwarding to take place, an external port is mapped on the internal port and Internal IP address. External devices send different packets to the external port and IP address.

Since this port connects to the internet, you can configure it by proceeding to system then network pages. Once there, you will see the section labeled external port. Click on it then select settings. This should guide you to the configuration page. Follow the step by step instructions available then save your changes.


For port forwarding to be done successfully, you have to understand the role of internal and external ports. Internal ports manage LAN requests to resources and handle things such as web browsing and authentication. The external ports, on the other hand, manage different requests for users. Port forwarding involves mapping external ports to internal ports. Both internal and external ports work together and, therefore, don’t have a lot of differences. Before you, however, implement port forwarding in your router, you should weigh its benefits against its risks.


During port forwarding, should I forward both the TCP and UDP ports?

This depends on the specific application you are handling. Start by checking the specific ports the precise application utilizes.

What is NAT?

Network address translation is used to isolate your home network from the net.

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