ConnectionMonitor.sh

#!/bin/bash

# Autor: John Llewelyn
# FB: fb.com/johnwilliam.llewelyn
# Twitter: twitter.com/JWLLEWELYN
# TLF: +584-1491-011-15
# Its use is free.
# Description: Connection Monitor for ADSL modem.
# Requirements:
# Copy this code or save to /home/administrator/ConnectionMonitor.sh
# It requires the installed packages fping beep and cron
# Comment the blacklist pcspkr snd-pcsp in /etc/modprobe.d/blacklist.conf
# Give execute permissions: chmod +x /home/administrator/ConnectionMonitor.sh
# Add this line in crontab -e with root user
# @reboot sleep 120 && /home/administrator/MonitorDeConexion.sh

#################################################################################
# SETTINGS
TEST="8.8.8.8"       # Ping Test
ADAPTER1="enp4s0"    # External Ethernet Adapter
TIMECHECK="120"      # Time to check the internet connection
# Report
LOGFILE="/home/administrator/Documentos/ReportInternet.log"

# Messages
MESSAGE1="Restoring Connectivity..."
MESSAGE2="Wait a moment please..."
MESSAGE3="No Internet connectivity."
MESSAGE4="Yes, there is Internet connectivity."
#################################################################################

# Time and Date
TODAY=$(date "+%r %d-%m-%Y")

# Show IP Public Address
IPv4ExternalAddr1=$(ip addr list $ADAPTER1 |grep "inet " |cut -d' ' -f6|cut -d/ -f1)
IPv6ExternalAddr1=$(ip addr list $ADAPTER1 |grep "inet6 " |cut -d' ' -f6|cut -d/ -f1)

# Alarm
alarm() {
    beep -f 1500 -l 200;beep -f 1550 -l 200;beep -f 1500 -l 200;beep -f 1550 -l 200;beep -f 1500 -l 200;beep -f 1550 -l 200;beep -f 1500 -l 200;beep -f 1550$
}

# Restoring Connectivity
resolve() {
    clear
    echo "${MESSAGE1}"
    sudo ifconfig ${ADAPTER1} up;sudo dhclient -r ${ADAPTER1};sleep 5;sudo dhclient ${ADAPTER1}
#   killall -SIGUSR2 udhcpc;sleep 5;killall -SIGUSR1 udhcpc
    echo "${MESSAGE2}"
    sleep 120
}

# Execution of work
while true; do
    if [[ "$(fping -I ${ADAPTER1} ${TEST} | grep 'unreachable' )" != "" ]]; then
        alarm
        clear
        echo "================================================================================" >> ${LOGFILE}
        echo "${MESSAGE3} - ${TODAY}"                                                               >> ${LOGFILE}
        echo "${MESSAGE3 - ${TODAY}"
        echo "================================================================================" >> ${LOGFILE}
        sleep 10
        resolve
    else
        clear
        echo "================================================================================"   >> ${LOGFILE}
        echo "${MESSAGE4} - ${TODAY} - IPv4 Addr: ${IPv4ExternalAddr1} - IPv6 Addr: ${IPv6ExternalAddr1}" >> ${LOGFILE}
        echo "${MESSAGE4} - ${TODAY} - IPv4 Addr: ${IPv4ExternalAddr1} - IPv6 Addr: ${IPv6ExternalAddr1}"
        echo "================================================================================"   >> ${LOGFILE}
        sleep ${TIMECHECK}
    fi
done