...Everything works out of the box.
CacheGuard-OS is not an app, it IS the OS. A fully custom network appliance operating system built from scratch over 20 years, now fully open source.
One ISO includes: firewall, VPN, web antivirus, URL filtering, SSL inspection, WAF, reverse proxy, load balancer and QoS.
Free for any number of users. Optional paid support available.
Source code: https://github.com/cacheguard/CacheGuard-OS
Website: https://www.cacheguard.com/