For people interested in building a firewall or just boards with multiple GbE ports I can recommend a swiss company PC Engines https://pcengines.ch/apu2.htm
They make really nice x86 boards with AMD chips.
The Dell is a complete computer in a box.
Contrast to PC engines, which sell a collection of parts. A motherboard, a case, an AC adapter. Etc.
Oh, and btw careful how you mount the motherboard. I.e.: Conductive cooling from the CPU to the enclosure through a 3 mm alu heat spreader. Please contact us for advice if you want to integrate this board in your own enclosure.
Not that the PC Engines stuff is bad; it's just that I usually prefer to have the manufacturer screw things together and then test the final product.