#WiFi
2 articles
Network / VPN
Tell a Broken Link from an ISP Outage Before Restarting Anything
A typical watchdog restarts NetworkManager when ping fails, which is wrong half the time because no internet access may mean the ISP is down, not that the adapter has failed. This article distinguishes three states using nmcli, then escalates from gentle recovery to PCI remove and rescan without rebooting the machine.
Planning 2.4GHz WiFi Channels 1/6/11 and Multi-Floor Heatmaps
A five-story building with seven APs per floor needs a 2.4GHz channel plan that avoids overlap both horizontally and vertically. This article covers the 1/6/11 principle, per-floor channel tables, the actual Tx power and RSSI threshold settings, and a Python script that labels floor plans with channels using PIL before a walkthrough survey to create a heatmap.