Useful system commands

As a Unix-like system, OPNsense has a lot of useful commands. In the following, we will explore some of these commands.

Let's dive into a practical scenario.

Assume that you lost access to the webGUI and want to find which process is using Transmission Control Protocol (TCP) port 443 on OPNsense. We can find running processes with listening ports on FreeBSD using the sockstat command:

root@bluebox:/usr/local/etc # sockstat -4l -p 443
USER     COMMAND    PID   FD PROTO  LOCAL ADDRESS         FOREIGN ADDRESS      
root     nginx   7065  5  tcp4   *:443                 *:*

In this example, the nginx process is using port 443 (just the IPv4 address...