networkcheck

#!/bin/bash

destination_host=$(/sbin/ip route | awk '/default/ { print $3 }')
if [[ $destination_host != "" ]]; then # check if we have default route (connected to router)
    echo "Default gateway found $destination_host ..."
    ping -c4 $destination_host >/dev/null # check if destination is reachable - possible by default the router
    if [ $? != 0 ]; then
        echo "Destination not reachable - reconfigure interface..."
        sudo wpa_cli -i wlan0 reconfigure # reconfigure network to trigger reconnect
        sudo dhclient -v                  # ensure connection will be established by refresh dhcp lease
        echo "Reconnect done."
        exit 0 # if we detect multiple network configs exit after 1st one - one reconnect is enough :-)
    else
        echo "Destination reachable - no action needed."
        exit 0 # destination reached - exit loop
    fi
fi