I've been using OpenBSD on my router/firewall boxes (in various forms, mostly i386/amd64 - Soekris or PC enginers but also mips/octeon - Ubiquiti boxes) for the

I've been using OpenBSD on my router/firewall boxes (in various forms, mostly i386/amd64 - Soekris or PC enginers but also mips/octeon - Ubiquiti boxes) for the past 20+ years. Mostly because in that area I do not want any compromises (literally and figuratively) on security. I like the Packet Firewall philosophy and functionality. The fact it is rock solid I take for granted. Another reason is that the system is cleanly designed and simple. Quite easy to reason about with source code in hand.