因为家里的光猫不会自动重新下发ipv6-pd，所以写了一个脚本，当openwrt路由器ipv6路由不可达时自动重启wan6接口

ipv6-prefix-change.sh

#!/bin/sh


FLAG_FILE="/tmp/ipv6_prefix_change_flag"

FLAG_VALUE=$(cat $FLAG_FILE 2>/dev/null)
if [ "$FLAG_VALUE" = "1" ]; then
    logger -t prefix_change "Script is already running. Skipping execution."
    exit 0
fi

echo "1" > $FLAG_FILE

IPV6_DEFAULT_ROUTE=$(ip -6 route | grep default 2>/dev/null)
if [ -z "$IPV6_DEFAULT_ROUTE" ] ; then
    logger -t prefix_change "IPv6 route missing detected. Reconnecting wan6 interface."
    ifdown wan6
    ifup wan6
fi

echo "0" > $FLAG_FILE