OPNsense is an open source, FreeBSD-based firewall and routing platform developed by the Dutch company Deciso.  Launched in 2015 as a fork of pfSense and m0n0wall, it is designed to provide cutting-edge network protection with a user-friendly web interface, comparable to expensive commercial security products but with verifiable open-source code. In this journal, I walk through the installation process for OPNsense 26.7. After completing the installation, I’ll