====== To Fix ======
===== Wait for network =====
google: linux bash does not recognize when network comes up
  * use ping<code>#!/bin/bash
    TARGET_HOST="8.8.8.8"
    while ! ping -c 1 "$TARGET_HOST" &> /dev/null; do
        echo "Waiting for network connectivity..."
        sleep 5 # Wait 5 seconds before retrying
    done
    echo "Network is up! Continuing with script..."
    # Your network-dependent commands here
</code>
  * check network interface state<code>#!/bin/bash
    INTERFACE="eth0" # Replace with your actual interface name
    while [[ $(</sys/class/net/${INTERFACE}/operstate) != "up" ]]; do
        echo "Waiting for interface $INTERFACE to be up..."
        sleep 5
    done
    echo "Interface $INTERFACE is up! Continuing with script..."
    # Your network-dependent commands here
</code>
google: linux interface up when no router

===== NUT for APC SRV1K =====
  * [[https://networkupstools.org/docs/man/huawei-ups2000.html|HUAWEI-UPS2000(8)]]
  * google "nut with qinheng electronics ch341"
  * ''systemctl reload nut-server''
  * google "nut driver not connected"
  * google "how to create driver for nut in debian 12"