2009-12-24-a-little-bash-of-network-monitoring.sh

#!/bin/bash

SOURCE="monitor01.t3ch.com"
SUBJECT="Network Alert: Node unreachable"
TO="youremail@t3ch.com"
MESSAGE="/tmp/network_monitor-message.txt"

for ipaddr in `cat nodes.list`;
    do
        if ! ping -c 1 $ipaddr
            then
                echo "Node: $ipaddr" > $MESSAGE
                echo "When: `date`" >> $MESSAGE
                echo "Source: $SOURCE" >> $MESSAGE
                /usr/bin/mail -s "$SUBJECT" "$TO" < $MESSAGE
                rm $MESSAGE
        fi
done