脚本收集于恩山，亲测可用于Openwrt系统宽带掉线检测与重拨，每5min即可执行一次并生成my_pppoe.log 日志文件。

#!/bin/sh
#网络检测脚本 通过PING来判断网络互通状态
#参数
#testing_ip=目标IP地址  detection_times=检测次数  Interval_time=间隔时间(秒)
#状态解释state
#start=开始检测  ok=网络连通  no=网络断开重试
#restart wan=重连WAN  restart wan ok=重连WAN完成
#restart network=重启网络进程  restart network ok=重启网络进程完成
#restart reboot=重启路由  restart reboot ok=重启路由完成
#脚本目录下日志文件my_pppoe.log 最大512K超出自动清空
#BY:朱君绰绰 V1.4
#其他重启命令
#ifup wan=重连WAN
#/etc/init.d/network restart=重启网络进程
#reboot=重启路由
#shell测试命令
#./my_pppoe.sh restart1
#echo $1

function Get_local_time(){
    date_time=`date +"%Y-%m-%d %H:%M:%S"`;
}
function text_log_size(){
    if [ -f $1 ]
    then
        filesize=`ls -l $1 | awk '{ print $5 }'`
        maxsize=$((1024*512))
        if [ $filesize -gt $maxsize ]
        then
            echo "$filesize > $maxsize"
            echo "log cleared" >$1
        else 
            echo "$filesize < $maxsize"
        fi
    fi 
}

testing_ip=114.114.114.114
testing_ip2=202.108.22.5
detection_times=3
Interval_time=10
detection_count=0
WebError=0
text_log=my_pppoe.log

text_log_size $text_log
Get_local_time
echo $date_time -- my_pppoe -- state:start >>$text_log
while [[ $detection_count -lt $detection_times ]]
do
    if /bin/ping -c 1 $testing_ip >/dev/null
    then
        Get_local_time
        echo $date_time -- my_pppoe -- state:ok ping=$testing_ip>>$text_log
        WebError=0
        break
    else    
        if /bin/ping -c 1 $testing_ip2 >/dev/null
        then
            Get_local_time
            echo $date_time -- my_pppoe -- state:no ping=$testing_ip -->>$text_log
            echo $date_time -- my_pppoe -- state:ok ping=$testing_ip2>>$text_log
            WebError=0
            break
        else
            detection_count=$((detection_count + 1))
            Get_local_time
            echo $date_time -- my_pppoe -- state:no ping=$testing_ip -->>$text_log
            echo $date_time -- my_pppoe -- state:no ping=$testing_ip2 -->>$text_log
            echo $date_time -- my_pppoe -- state:ping retry $detection_count-$detection_times>>$text_log
            WebError=1
            sleep $Interval_time
        fi
    fi
done

if [ $WebError = 1 ]
then
    if [ $1 = restart1 ]
    then
        Get_local_time
        echo $date_time -- my_pppoe -- state:restart wan >>$text_log
        ifup wan
        Get_local_time
        echo $date_time -- my_pppoe -- state:restart wan ok >>$text_log
    fi

    if [ $1 = restart2 ]
    then
        Get_local_time
        echo $date_time -- my_pppoe -- state:restart network >>$text_log
        /etc/init.d/network restart
        Get_local_time
        echo $date_time -- my_pppoe -- state:restart network ok >>$text_log
    fi  

    if [ $1 = restart3 ]
    then
        Get_local_time
        echo $date_time -- my_pppoe -- state:restart reboot >>$text_log
        Get_local_time
        echo $date_time -- my_pppoe -- state:restart reboot ok >>$text_log
        reboot
    fi
fi

exit 0



#end