firewall

OPNsense WAN Watchdog with Cooldown, Log Rotation & Cron Integration. PART 1

This guide outlines the steps to create a cron-activated recovery script for OPNsense 25.7.7_4 to address DHCP outages. The script monitors connectivity, logs activity, and reconfigures the WAN interface as needed. It implements cooldown mechanisms to prevent reboot loops and integrates with the system's configuration and scheduling functions.

Nov 14, 2025

OPNsense: Automatic Recovery When WAN Fails

This post addresses the absence of a built-in WAN recovery mechanism in OPNsense 25.7.7_4, which can lead to internet connection loss requiring manual reboot. The author presents a DIY solution: a shell script that pings a reliable host, attempts to renew DHCP leases, and reboots the system if necessary. The script can be scheduled via cron for regular monitoring, enhancing network reliability.

Sep 3, 2025

Running OPNsense on the HP T740 — Fixing GIANT-LOCKED and Power Recovery Issues

The article addresses the "GIANT-LOCKED" boot issue and power recovery problems encountered when using OPNsense on HP T740 thin clients. The root cause lies in the legacy device probing by FreeBSD's firmware, which can lead to system freezes and improper resets following a power cut. Solutions involve modifying the boot loader configuration to disable legacy device probing and manage ACPI settings, ensuring reliable system operation without external peripherals.

Aug 31, 2025

Secure Your Linux Laptop With iptables

Your linux powered laptop is open and vulnerable. Let's harden it a little with the linux iptables firewall. It's not that hard, honest... it is just a text file.

Sep 23, 2022