Invalid Range of Ports: 6 Ways to Easily Fix It

If you try to make services on a host on a protected or internal network available to hosts on the other side of the gateway or external network, you may receive an error notice that says: incorrect range of ports.

This indicates that the port forwarding is not working, and there might be several causes for this. Since the topic revolves around ports and port forwarding, we will go over what they are and how to utilize them first.

In addition, we will go over all of the potential concerns and solutions for the invalid port range.

What Are Ports?

Ports are virtual channels via which network connections begin and finish. Because devices communicate a lot via the internet, ports are created to speed things up. Certain data is sent through certain ports, allowing the internet to be more defined and quicker.

Ports contain numbers that aid in the identification of the data that is permitted via that port.

Here are some examples:

  1. Ports 20 and 21: File Transfer Protocol (FTP)
  2. Port 22: Secure Shell (SSH)
  3. Port 25: Simple Mail Transfer Protocol (SMTP)
  4. Port 80: Hypertext Transfer Protocol (HTTP)
  5. Port 500: Internet Security Association and Key Management Protocol (ISAKMP)
  6. Port 3389: Remote Desktop Protocol (RDP)

Is opening a port dangerous?

If you wish to open ports on an Arris router, you may be wondering if it is a safe and wise option. While most people prefer to keep the ports closed to decrease the danger of attack, there are ways to keep them open and secure.

There are misuses of opened ports, and you should be cautious, but the ports must be opened in order to connect to the internet, therefore the answer is that not all ports are hazardous to open.

When the service listening on the port is misconfigured or has weak network security policies, open ports might be harmful.

What Is Port Forwarding?

Port forwarding, also known as port mapping, enables computers or services on private networks to communicate with other public or private computers or services through the internet.

Your router serves as the link between your devices and the internet. When your device, such as a laptop, desktop, or mobile phone, connects to the internet, it is assigned a unique IP address.

When you search for anything on the internet, your device sends the request to your router, which masks your IP address and forwards the request with a public IP address and over particular ports.

When the returned data arrives at your router, it utilizes Network address translation (NAT) to translate it and send it to the correct device.

Port forwarding is significant because it allows access to objects on private networks. Firewalls on the router serve as the first line of protection against unauthorized network invaders. If the correct port is used and the IP address matches, the data is sent.

Port forwarding may not work if the server IP address is not in a valid range.

What Is Port Forwarding Used For?

Port forwarding is utilized in a variety of situations. You will require that extra authentication whenever you try to access your device on a private network.

Because router firewalls are meant to keep undesirable visitors out, you must ensure that port forwarding has the correct information to transmit through the firewalls and to the appropriate destination on the network.

There are three types of port forwarding:

  1. Local port forwarding
  2. Remote port forwarding
  3. Dynamic port forwarding

You may use port forwarding to connect to any device or server on a private network. This may be highly handy for security, virtual desktops, and a variety of other applications.

How to Fix “Invalid Range of Ports”?

If you notice the message invalid range of ports, the most likely cause is that you made a mistake when setting up the port forwarding. These errors might include typos, numeric errors, and other types, and all of these can be the reasons for port forwarding not working.

There are straightforward fixes to each error that results in an invalid range of ports, and we will explain all of them below.

Check Source/Destination

Before creating the port forwarding, ensure that the source and destination are both identified and properly inputted. Incorrect input in these areas will cause problems and prevent port forwarding from working.

Furthermore, there might be a slew of error messages reported with no idea what the issue is.

When there is a problem with port forwarding, address the source and destination first to ensure that you have supplied the system with accurate information.

Port Range Forwarding

The range of ports must be properly defined in order for the router to allow information to pass through. Fill down the precise port numbers with care, then double-check all of the data.

The sequence in which you list the ports must also be exact. Depending on the router you are using, the numbers must be typed in ascending order.

Pay close attention to the separator, which is generally a dash. Consider the starting and ending ports as well.

Check Numeric Values

Values supplied within the specified field while establishing port formatting must be numeric. 

Because the ports are all numbered, and those numbers are the critical component that distinguishes one port from another, even the tiniest inaccuracy will result in the problem described.

The ports are numbered from zero to 65,535 with zero being the default. As a result, double-check that you entered the correct number. 

Missing Information

Sometimes fields are left totally blank, which, among other things, might be the source of the error notice.

Depending on the router, different fields may be required, and they must all be filled out for port forwarding to work.

Consider sending a letter with no address and only a name. It is unlikely to reach its intended recipient, and the same is true for information delivered over the internet.

Fill out all of the needed information to ensure that your port forwarding works properly.

Update the Firmware

If you have tried everything else and the forward ports on the Arris router are still not functioning, you might try updating the firmware. Some firmware upgrades will fix the issue.

You should check for updated versions of the firmware on a regular basis, just like you would for any other upgrade. Newer versions have upgraded firewalls, which may address your port forwarding issue.

If port forwarding is not working, there may be issues with firewalls that are preventing information from passing through. Because firewalls are designed to keep intruders out, upgrading the firmware may be the solution.

Restart the Router

Restarting the router or performing a factory reset can occasionally address the problem of an invalid range of ports.

Restarting the router is the easiest technical thing you can do to fix the problem, and it can be done in a few easy steps, starting with turning off your router and waiting a few minutes before restarting it.

This will allow the router to reconnect and create an internet connection, as well as potentially allowing you to port forward.

With the router back up and running, the firewalls are activated as well. If this does not work, check for updates as indicated in the previous step.

Tips For Better Port Forwarding 

Port forwarding may be utilized for a variety of practical and entertaining purposes. We will go through a few examples to help you understand what is port forwarding and where it is used.


One of the most common applications for port forwarding is to run private gaming servers such as Minecraft.

This is a fun and interesting method to establish private servers that only friends and family have access to.

The gaming business is one of the most profitable nowadays, therefore it is not unexpected that many firms take advantage of this chance or establish servers for competition, and sometimes even to raise money for charity.


When it comes to your belongings, you can never have too much security, therefore installing and using security cameras may be a smart option.

If you have ever wondered how security cameras may be monitored while you are not at home, the solution is port forwarding.

With this incredible function, you will be able to access and watch your security cameras from any location.

This may be highly useful and simple to implement. However, you must exercise extreme caution and maintain the highest security standards to prevent attackers from logging in to your cameras and invading your privacy.

Virtual Desktops

Virtual desktop or VDI, is gaining popularity, particularly in big institutions such as hospitals and colleges. This is one of the solutions for port forwarding in Arris router with which users may access their virtual desktops from any place.

This is an excellent method to save space and money while keeping all critical information and data secure.

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