Anyone who has been around the world of Unix security firewalls and minimalist server systems for a while remembers the grey-green or dark cases from Soekris Engineering with a certain nostalgia. For years, the Soekris net5501 🛒Affiliate Link: I may receive a small commission at no extra cost to you when you buy via this link. A way to support my work. was the gold standard for highly reliable, fanless embedded routers and network appliances running OpenBSD.