#!/bin/bash
date
# wait for first response of router or some other host,
# waiting for a maximum of 10 seconds for that reply
ping -c 1 -w 10 192.168.1.1
# with default interval (1 second), this program should send up to 10 ping packets

sudo touch /var/log/networkwatchdog.log
sudo chown USER:USER /var/log/networkwatchdog.log

*/30 * * * * /path/to/script/networkwatchdog.sh &> /var/log/networkwatchdog.log