Here my script (CheckVPN.sh) to check the status of VPN with logs in syslog :
# cat ./CheckVPN.sh
grep "naclient_poll" /var/log/syslog* | sed 's/:/ /1' | awk '{print $2 " " $3 " " $4 " " $10}' | sort > /tmp/naclient_poll.txt
filename='/tmp/naclient_poll.txt'
n=1
m=0
previous_state=0
while read line; do
state=`echo $line | awk '{print $4}'`
if [ $previous_state = $state ]
then
#echo "Line No. $n $state : $line"
m=$((m+1))
else
echo "Line No. $n $state (new state) $m : $line"
if [ $previous_state = 1 ]
then
echo " Network is down"
fi
if [ $state = 1 ]
then
echo " Network is up"
fi
previous_state=${state}
m=0
fi
n=$((n+1))
done < $filename