In today’s IT landscape, companies are increasingly faced with the challenge of operating networks securely, reliably and efficiently. Many firewall solutions are expensive, oversized or unnecessarily complex. Our answer: a compact, powerful and energy-saving system that meets all modern requirements – the PC Engines APU4D4 in a 1U 19-inch rack housing, equipped with the proven OPNsense® open source firewall.

What is the APU4D4?

The APU4D4 is an embedded system from the popular APU series from PC Engines. These boards are specially developed for network applications – robust, reliable and without unnecessary ballast.

The APU4D4 model has:

• An AMD GX-412TC quad-core processor with 1 GHz – fanless, energy-saving, reliable
• 4 GB DDR3L RAM (permanently installed)
• 4x Intel i210AT Gigabit Ethernet ports – ideal for multi-WAN, VLANs or segmented networks
• Expansion options via 3 MiniPCIe slots (e.g. WLAN or LTE), mSATA, SATA and microSD
• Serial console (RS232) – important for headless configurations or troubleshooting

The board was designed for continuous operation in the network environment and shows its strengths above all when it comes to security, efficiency and long-term availability.

Our complete system: rackable & ready for use

We supply the APU4D4 fully assembled in a sturdy 1U 19-inch housing:

• Network ports routed to the front for neat cable management
• Passive cooling – 100 % silent
• High-quality power supply unit (12 V DC)
• Pre-installed SSD (32 GB mSATA SSD)
• Optional expansion with LTE, WLAN or GPS modules via MiniPCIe

Each device is checked by us before dispatch, installed ready for operation and can be delivered with individual network settings on request.

Enterprise-level security with OPNsense®

OPNsense® is a modern firewall distribution based on FreeBSD®, developed for professional requirements. The open source software offers a powerfuland transparent alternative to commercial solutions such as pfSense®, Sophos®, or FortiGate®.

Features at a glance:

• Intuitive, web-based interface (HTTPS)
• Stateful firewall with NAT, logging & aliases
• VPN: IPsec, OpenVPN, WireGuard®
• IDS/IPS: Suricata integration for real-time threat detection
• Traffic shaping: bandwidth management on an interface, port or IP basis
• Captive Portal: Guest access with authentication
• High availability via CARP (e.g. for redundant systems)
• Regular updates & community support

The decisive advantage: full control over network security, without license costs or dependence on a single manufacturer.

Use cases: Who is the system suitable for?

Our APU4D4 rack system is particularly suitable for:

Small & medium-sized enterprises (SMEs):

• Secure connection of locations via VPN
• Guest WLAN with authentication
• Separation of departments through VLANs & firewall rules

System houses & MSPs:

• Customer firewalls with simple management via the OPNsense web interface
• Remote maintenance, monitoring, logging – out of the box

Educational institutions:

• Access control via captive portals
• Bandwidth restriction for certain user groups

Technical private users:

• Replacement for conventional home routers
• Enterprise-level network security for the home or home office

Sustainability & energy efficiency

With a power consumption of only around 6-10 watts in normal operation, the APU4D4 is particularly energy-efficient. Compared to classic firewall appliances or disused office PCs, you not only save space and noise, but also electricity costs in the long term – without any loss of performance.

Expandable

Thanks to the MiniPCIe slots, the system can be flexibly expanded. Possible are e.g:

• LTE modem with SIM card slot – for backup connections or mobile use
• WLAN modules – e.g. for access points or mesh networks
• GPS modules – e.g. for time servers or fleet use

OPNsense is also modularly expandable on the software side – with plug-ins for NetFlow, WireGuard, HAProxy, Let’s Encrypt and much more.

Our conclusion: The clever firewall solution for professionals

Whether in the company, laboratory, data center or at home – our 19-inch rack system with APU4D4 and OPNsense® offers a modern, low-maintenance and powerful firewall and routing platform based on free software. Secure. Flexible. Economical.