Check also the PCEngines APU boards at https://pcengines.ch https://pcengines.ch Also interesting are the NanoPi R2S and R4S at https://www.friendlyarm.com htt

Check also the PCEngines APU boards at https://pcengines.ch https://pcengines.ch Also interesting are the NanoPi R2S and R4S at https://www.friendlyarm.com https://www.friendlyarm.com Especially those by PCEngines are designed for that job; I've used their Wrap boards in the past as firewalls with PfSense and they were rock solid. No affiliation with any of them, just a satisfied customer.