openwrt lan口未知原因断网的修补方案记录

前言：

由于openwrt出现莫名故障，暂未查明具体原因，临时写了个脚本进行补救，该文对此进行记录。

故障描述：

主要硬件信息：

cpu：N3150

网卡：

root@OpenWrt:~# lspci|grep -i 'eth'
01:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 07)
02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 07)

故障表现：

lan口随机出现断网情况，拔插lan口连接ap的网线即可再次正常工作，并且日志中并无故障相关信息，暂未找到实际原因。

怀疑过系统问题，刷了多个版本的openwrt后故障依然存在。怀疑过与ap不兼容，在lan口加交换机后连接ap，依然会出现该问题。拔插交换机-op段的网线可恢复，拔插交换机-ap段的网线无效。

解决思路：

由于并未找到实际原因，以及拔插lan口后可以恢复网络，打算暂时写个脚本让主路由能正常工作。具体逻辑是通过循环ping ap的ip判断内网是否通畅，不通畅则重启lan口。

ping -c 1 -W 1 ip;ping检测命令，超时判断减少为1s
ifup lan;#重启lan口命令

初始代码：

ip=192.168.3.2;#此处填内网验证ip
for((i=0;i<10;i=(i)))#勿吐槽，随便写了个死循环
do
/bin/ping -c 1 -W 1 $ip
if [ $? -eq 0 ]; then
echo "ping $ip success!"
else
echo "ping $ip fail!"
logger "lan error, restart lan"
ifup lan
sleep 6;
fi
sleep 1;
done

该代码能实现基本要求，但是考虑到有一定几率杀后台，所以需要加入守护。这里我偷个懒，直接用crontab每几分钟调用一次，脚本只需要判断是否有脚本在运行即可，如果没有运行则继续运行。

info=`ps | grep /root/ping_test.sh | grep -v grep | cut -d " " -f 1`;#用于检测是否已经运行，路径填完整防止与其他冲突
info=($info)#转成数组，方便判断有几个后台在运行。

最终代码：

#!/bin/bash
info=`ps | grep /root/ping_test.sh | grep -v grep | cut -d " " -f 1`;
info=($info)
#echo $info
#echo ${#info[@]}
ip=192.168.3.2;#此处填内网验证ip
if [ ${#info[@]} = 2 ];then #有两个结果则开始运行
for((i=0;i<10;i=(i)))
do
/bin/ping -c 1 -W 1 $ip
if [ $? -eq 0 ]; then
echo "ping $ip success!";
else
echo "ping $ip fail!";
logger "lan error, restart lan!";
ifup lan;
sleep 6;
fi
sleep 1;
done
else
echo "still running";
fi

将文件保存为ping_test.sh，保存在/root/路径下，之后再crontab中写入计划任务，可每分钟执行一次，自行调整。

1 * * * * /bin/bash /root/ping_test.sh &

或者

1 * * * * nohup /bin/bash /root/ping_test.sh >/dev/null 2>&1 &

执行结果日志：

ip信息已删除

Sun Feb 19 06:37:07 2023 daemon.info watchcat[25546]: Could not reach 8.8.8.8 for 60. Rebooting after reaching 21600

此处成功发现内网已经断开，将lan口重启
Sun Feb 19 06:38:48 2023 user.notice root: lan error, restart lan!
Sun Feb 19 06:38:48 2023 daemon.notice netifd: Interface 'lan' is now down
Sun Feb 19 06:38:48 2023 daemon.info avahi-daemon[3771]: Withdrawing address record for 240e:::::1 on eth0.
Sun Feb 19 06:38:48 2023 daemon.notice ttyd[19019]: [2023/02/19 06:38:48:4523] N: rops_handle_POLLIN_netlink: DELADDR
Sun Feb 19 06:38:48 2023 daemon.info avahi-daemon[3771]: Registering new address record for fe80:::::4e24 on eth0.*.
Sun Feb 19 06:38:48 2023 daemon.info avahi-daemon[3771]: Registering new address record for 240e:::::1 on eth0.*.
Sun Feb 19 06:38:48 2023 daemon.info avahi-daemon[3771]: Withdrawing address record for 192.168.3.1 on eth0.
Sun Feb 19 06:38:48 2023 daemon.info avahi-daemon[3771]: Leaving mDNS multicast group on interface eth0.IPv4 with address 192.168.3.1.
Sun Feb 19 06:38:48 2023 daemon.notice ttyd[19019]: [2023/02/19 06:38:48:5212] N: rops_handle_POLLIN_netlink: DELADDR
Sun Feb 19 06:38:48 2023 daemon.notice ttyd[19019]: [2023/02/19 06:38:48:5213] N: rops_handle_POLLIN_netlink: DELADDR
Sun Feb 19 06:38:48 2023 daemon.notice ttyd[19019]: [2023/02/19 06:38:48:5214] N: rops_handle_POLLIN_netlink: DELADDR
Sun Feb 19 06:38:48 2023 daemon.notice netifd: Interface 'lan' is disabled
Sun Feb 19 06:38:48 2023 daemon.notice netifd: Network device 'eth0' link is down
Sun Feb 19 06:38:48 2023 daemon.notice netifd: Interface 'lan' has link connectivity loss
Sun Feb 19 06:38:48 2023 daemon.info avahi-daemon[3771]: Interface eth0.IPv4 no longer relevant for mDNS.
Sun Feb 19 06:38:48 2023 daemon.info avahi-daemon[3771]: Interface eth0.IPv6 no longer relevant for mDNS.
Sun Feb 19 06:38:48 2023 daemon.info avahi-daemon[3771]: Leaving mDNS multicast group on interface eth0.IPv6 with address 240e:::1.
Sun Feb 19 06:38:48 2023 daemon.info avahi-daemon[3771]: Withdrawing address record for fe80:::4e24 on eth0.
Sun Feb 19 06:38:48 2023 daemon.info avahi-daemon[3771]: Withdrawing address record for fd1a:::1 on eth0.
Sun Feb 19 06:38:48 2023 daemon.info avahi-daemon[3771]: Withdrawing address record for 240e:::::1 on eth0.
Sun Feb 19 06:38:48 2023 kern.info kernel: [97420.894078] eth0: 0xffffc9000006d000, 00:00:00:00:00:00, IRQ 119
Sun Feb 19 06:38:48 2023 daemon.notice netifd: Interface 'lan' is enabled
Sun Feb 19 06:38:48 2023 daemon.notice netifd: Interface 'lan' is setting up now
Sun Feb 19 06:38:48 2023 daemon.info avahi-daemon[3771]: Joining mDNS multicast group on interface eth0.IPv4 with address 192.168.31.1.
Sun Feb 19 06:38:48 2023 daemon.info avahi-daemon[3771]: New relevant interface eth0.IPv4 for mDNS.
Sun Feb 19 06:38:48 2023 daemon.info avahi-daemon[3771]: Registering new address record for 192.168.31.1 on eth0.IPv4.
Sun Feb 19 06:38:48 2023 daemon.info avahi-daemon[3771]: Joining mDNS multicast group on interface eth0.IPv6 with address 240e:::1.
Sun Feb 19 06:38:48 2023 daemon.info avahi-daemon[3771]: New relevant interface eth0.IPv6 for mDNS.
Sun Feb 19 06:38:48 2023 daemon.notice netifd: Interface 'lan' is now up
Sun Feb 19 06:38:48 2023 daemon.info avahi-daemon[3771]: Registering new address record for 240e:::::1 on eth0.*.
Sun Feb 19 06:38:48 2023 daemon.info avahi-daemon[3771]: Registering new address record for fd1a::::1 on eth0.*.
Sun Feb 19 06:38:49 2023 daemon.err odhcpd[2637]: Failed to send to ff02::1%lan@eth0 (Address not available)
Sun Feb 19 06:38:50 2023 daemon.info samba4-server: io_uring module found, enabling VFS io_uring. (also needs Kernel 5.4+ Support)
Sun Feb 19 06:38:50 2023 daemon.info samba4-server: io_uring module found, enabling VFS io_uring. (also needs Kernel 5.4+ Support)
Sun Feb 19 06:38:50 2023 daemon.info samba4-server: io_uring module found, enabling VFS io_uring. (also needs Kernel 5.4+ Support)
Sun Feb 19 06:38:50 2023 daemon.info samba4-server: io_uring module found, enabling VFS io_uring. (also needs Kernel 5.4+ Support)
Sun Feb 19 06:38:52 2023 kern.info kernel: [97425.132501] r8168: eth0: link up
Sun Feb 19 06:38:52 2023 kern.info kernel: [97425.134542] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
Sun Feb 19 06:38:52 2023 daemon.notice netifd: Network device 'eth0' link is up
Sun Feb 19 06:38:52 2023 daemon.notice netifd: Interface 'lan' has link connectivity