Recently decided to get rid of my home broadband provided router (Amazon Eero) with an enterprise grade firewall features, without burning a hole in my wallet, using the Topton N100 mini PC. In this guide, I will walk through installing OPNsense, one of the most powerful open-source firewall platforms available today on this tiny box.
My goal is to have segmentation in my home network, blocking ads at the edge and just showing my friends my home lab which they have 0 interest in :D
Before starting, make sure you have the following:
✅ Topton N100 mini PC (the 4× Intel i226-V NIC version is ideal)
✅ USB drive (8GB or larger)
✅ External monitor and keyboard for the initial setup
✅ Another computer to download and flash the OPNsense image
✅ Optional: USB Ethernet adapter if you need additional network ports during installation
Once you’ve gathered your tools, it’s time to dive in.
Start by heading to the official website:
Go to the Downloads section and choose the VGA image (not the serial version) since we’re using a monitor for the installation.
Next, flash the ISO to your USB drive using one of these tools:
balenaEtcher
Rufus
dd (for Linux users)
In just a few minutes, your OPNsense installer will be ready to boot.
Connect the following to your Topton N100:
USB installer
Monitor
Keyboard
Power on the system and press DEL or F11 (this varies by unit) to enter the BIOS or boot menu.
Inside the BIOS:
Disable Secure Boot
Set the USB drive as the first boot device
Save your changes and exit.
You should see the OPNsense installer begin to load.
When the live environment loads, log in using:
Username: installer
Password: (blank or same as username depending on version)
Then:
Select Guided Installation
Choose your target drive (usually the internal M.2 SSD)
Wipe the disk and proceed
Set a strong root password you are the firewall now and you don’t want to get hacked straightaway
After installation finishes, reboot the device and remove the USB stick so it boots from your new OPNsense installation.
When OPNsense boots for the first time, you’ll see a console menu prompting you to assign network interfaces.
Typical setup:
igc0 → WAN
igc1 → LAN
After assigning interfaces, connect your LAN port to another computer and open:
👉 http://192.168.1.1
Log in with:
Username: root
Password: the one you set during installation
Welcome to your new firewall!
With OPNsense up and running, this is where the fun begins. Some recommended first steps:
✅ Update the system
✅ Configure DHCP and static mappings
✅ Create VLANs for network segmentation
✅ Set up WireGuard or other VPN services
✅ Enable intrusion detection (IDS/IPS) (More on an alternative to this in a following post)
This is where the Topton N100 really shines—plenty of power for advanced features, and plugins.
Your Topton N100 mini PC is now a fully functional OPNsense firewall, silent, power-efficient, and loaded with enterprise-grade capabilities.
If you’re leveling up your homelab, this is one of the best upgrades you can make.
If you would like a visual representation check this out: https://youtu.be/xtnhxOdqxH0