How to turn an old PC into a router

There are many things you can do with a computer that you no longer use, from turning it into a media server, from which to stream media, a local storage server or one for games. But today we treat you to a completely different one. Can you imagine your PC as an internet access router? Well, it is possible and we are going to explain how to do it and the basic elements you need.

The router that is responsible for managing the Internet connection of all the peripherals in your home may seem like a simple and simple box, however, it is in itself a complete computer, since it contains all the elements of a Von Neumann architecture. That is to say, a CPU, a RAM memory, a peripheral management and even a storage from which to execute an operating system. However, they are usually based on low-power hardware, usually derived from the world of mobile phones, to carry out their task. This means that when they have to manage many data packets and requests to the network, they become saturated.

How to turn an old PC into a router

Why do I want to turn my old PC into a router?

Well, due to the fact that nobody gives anything for free and if there is a problem in internet connections today that exists in many homes and small businesses, it is the use of a router with limited capabilities, which at the minimum that there are several devices connected at the same time becomes saturated. This worsens the connectivity to the network of networks and if you depend on it on a daily basis, either for leisure, for work or both, you do not deserve a poor quality connection.

The fact of mounting high-end network equipment can cost you very expensive, however, if you have an old tower or you can get a second-hand one you can save a lot of money and not only have a quality internet connection. Much safer and with more options than the one your standard provider gives you.

How to turn a PC into a router

It is important that the PC that we have acquired is a tower with at least three free PCI Express ports on its motherboard, which do not have to be new generation, it can be done with a PCI Express 3.0 connection. You can perfectly go for an office tower from a few years ago, but you should rule out MiniPCs and laptops because they lack such an interface. And what will we do with her?


PC como router torre


Connecting the PC to the fiber optic

Since today we connect to the internet through fiber optics, we are going to need a card that gives us this capacity. That is why one of the PCI Express x 4 ports will connect one of these cards. We have chosen a model that supports connectivity up to 10 Gbps and with a single port that costs less than 100 euros. Which is enough for the connections that most small offices and homes have.


Adding network ports

However, we need Ethernet ports to connect the devices and this is where things get a bit tricky as many network cards do not support Gigabit Ethernet speeds. In that case, simply and simply discard them, since they are going to be a bottleneck for you when it comes to internet access. On the other hand, keep in mind that such a card with many ports will divide the bandwidth between them equally.

Keep in mind that we need a port for each device that connects to the router to access the internet, it can be a console, a SmartTV, a PC. This is important due to the fact that each of them needs one. To them must be added the Wi-Fi access point that we will talk about later.

We leave you as an example a 4-port network card, do not be scared by the price, since you can opt for simpler solutions. In addition, the advantage of this type of network card is that it relieves the processor of the work of managing network packets between the different devices on the local network.


What PC configuration do I need to set it up as a router?

Well, it will depend on the network card you have chosen, if it has enough capacity and you have paid more for it, you will be able to work without problems with an Intel i3 and even a lower range. In the event that the choice is quite modest, then you should go for an i5. Keep in mind that the idea is that the PC works 24 hours a day and 7 days a week, do not go for something that has a high TDP as long as your electricity bill skyrockets.

  • In any case, with a dual-core processor, even one from five years ago or more, you will have enough. Try to have integrated graphics.
  • 4 GB of RAM in a single module will do the job without any problems, a larger configuration is always preferable.
  • A small capacity SATA SSD to store the operating system.

The ideal is a configuration that you can use without fans, if necessary we recommend lowering the CPU speed from the BIOS. Don’t worry, these PC processors have more capacity than what routers include.


And what about Wi-Fi?

Obviously, we are interested in being able to connect any device wirelessly, not only laptops, but also video game consoles, mobile phones. In addition, what will be necessary if we use a wireless printer. This is where we are going to spend more money on the entire installation, since the best option is a Wi-Fi access point connected to the PC as a router. The reason? If on the subject of drivers Linux goes a step back from Windows, if we talk about a derivative of FreeBSD, then things get complicated.

So you will have to connect your Wi-Fi access point to one of the LAN or Ethernet ports of your PC as a router to have wireless connectivity. It is an additional additional expense, but you will get much better wireless connectivity than what most devices that internet providers give away and, therefore, a higher quality connection.


What operating system to use?

As you may have guessed, we are not going to use Windows, since our objective is not to interact with our PC as a router directly, but indirectly. To do this we will install an operating system called OPNsense, which is based on FreeBSD. When downloading the image of the operating system, you must choose VGA, which will allow you to manage the system. As for the installation on the target system, this can be done in a simple way, however, you will need some elements.

  • You will need a FAT32 formatted USB stick to install OPNsense on your PC as a router, make sure you have one available and if needed you can use applications like Rufus to mount the image.
  • Make sure the boot sequence in the BIOS is set to read the USB port first and not the SATA SSD on the PC as a router
  • During the installation process you will need a screen, so make sure you have a free one connected to the PC as a router during the whole process.
  • Connect one cable and only one cable to each of the network card ports on the PC to make sure what the numbering of each of them is and shore it up. You will know this by the fact that the screen will indicate which ports are active at any given time.



When we start it will tell us that we are running the operating system in live mode, we are interested in installing it on the SATA SSD.

  1. To do this, in the login as username type installer and as password opensense.
  2. This will start the installation process where you will need to choose the supported keyboard type and the drive you want to install OPNsense to.
  3. In the middle of the installation we will be asked for a password for the Root user, the one with the most privileges, make sure it is secure and at the same time one that you can remember.
  4. Once finished, remove the USB flash drive and reboot your PC as a router. Since if you don’t, it will restart the installation process.

Instalador OPNsense para PC como router


Configuring the PC as a router

Now we have to check that everything is correct, disconnect the screen from the PC as a router and leave it on. The next thing will be to check that we can connect, either remotely or, failing that, through a network cable.

  1. From any PC connected to the network, type in the address bar A screen like the one you see below these lines will appear.
  2. It will ask you for credentials to enter. As Username write root and as Password the key you gave during the installation.
  3. From here you can configure all the options you want and need.
  1. OPNsense Login

That is why we recommend you print or write down the configuration of your router elsewhere, do not hesitate to ask your internet provider for the credentials and configuration of your service. Once you have everything assembled, you can enjoy a higher quality connection, with fewer crashes and higher performance. Believe us it is worth doing.