法大Openwrt配置IPv6和v2ray免流

前言

本人于2020年9月成功用Newifi 3 D2刷入Openwrt并成功开启NAT6.

这篇文章或许能帮助到你。

步骤

准备

1. 刷入openwrt或基于openwrt的固件，最好是原版。
2. 输入192.168.1.1配置好后台密码并开启ssh
3. 打开终端，（Windows系统：在左下角右键点击，开启Powershell；Mac系统，打开终端；Linux系统就不用多说了），输入’ssh [email protected]’，根据提示输入刚刚设置的密码。
4. 确保路由器正常联网。

安装nat6模块

终端输入opkg update && opkg install kmod-ipt-nat6，回车。

将IPv6 ULA Prefix由f改为d

终端输入uci set network.globals.ula_prefix="$(uci get network.globals.ula_prefix | sed 's/^./d/')" && uci commit network，回车。

将DHCP服务器设置为总是广播默认路由

终端输入uci set dhcp.lan.ra_default='1' && uci commit dhcp，回车。

生成NAT6脚本

终端输入touch /etc/init.d/nat6 && vi /etc/init.d/nat6，回车。

按键盘I键，将以下内容复制进入终端窗口。

#!/bin/sh /etc/rc.common
# NAT6 init script for OpenWrt // Depends on package: kmod-ipt-nat6
START=55
# Options
# -------
# Use temporary addresses (IPv6 privacy extensions) for outgoing connections? Yes: 1 / No: 0
PRIVACY=1
# Maximum number of attempts before this script will stop in case no IPv6 route is available
# This limits the execution time of the IPv6 route lookup to (MAX_TRIES+1)*(MAX_TRIES/2) seconds. The default (15) equals 120 seconds.
MAX_TRIES=15
# An initial delay (in seconds) helps to avoid looking for the IPv6 network too early. Ideally, the first probe is successful.
# This would be the case if the time passed between the system log messages "Probing IPv6 route" and "Setting up NAT6" is 1 second.
DELAY=5
# Logical interface name of outbound IPv6 connection
# There should be no need to modify this, unless you changed the default network interface names
# Edit by Vincent: I never changed my default network interface names, but still I have to change the WAN6_NAME to "wan" instead of "wan6"
WAN6_NAME="wan6"
# ---------------------------------------------------
# Options end here - no need to change anything below
boot() {
        [ $DELAY -gt 0 ] && sleep $DELAY
        logger -t NAT6 "Probing IPv6 route"
        PROBE=0
        COUNT=1
        while [ $PROBE -eq 0 ]
        do
                if [ $COUNT -gt $MAX_TRIES ]
                then
                        logger -t NAT6 "Fatal error: No IPv6 route found (reached retry limit)" && exit 1
                fi
                sleep $COUNT
                COUNT=$((COUNT+1))
                PROBE=$(route -A inet6 | grep -c '::/0')
        done
 
        logger -t NAT6 "Setting up NAT6"
 
        WAN6_INTERFACE=$(uci get "network.$WAN6_NAME.ifname")
        if [ -z "$WAN6_INTERFACE" ] || [ ! -e "/sys/class/net/$WAN6_INTERFACE/" ] ; then
                logger -t NAT6 "Fatal error: Lookup of $WAN6_NAME interface failed. Were the default interface names changed?" && exit 1
        fi
        WAN6_GATEWAY=$(route -A inet6 -e | grep "$WAN6_INTERFACE" | awk '/::\/0/{print $2; exit}')
        if [ -z "$WAN6_GATEWAY" ] ; then
                logger -t NAT6 "Fatal error: No IPv6 gateway for $WAN6_INTERFACE found" && exit 1
        fi
        LAN_ULA_PREFIX=$(uci get network.globals.ula_prefix)
        if [ $(echo "$LAN_ULA_PREFIX" | grep -c -E "^([0-9a-fA-F]{4}):([0-9a-fA-F]{0,4}):") -ne 1 ] ; then
                logger -t NAT6 "Fatal error: IPv6 ULA prefix $LAN_ULA_PREFIX seems invalid. Please verify that a prefix is set and valid." && exit 1
        fi
 
        ip6tables -t nat -I POSTROUTING -s "$LAN_ULA_PREFIX" -o "$WAN6_INTERFACE" -j MASQUERADE
        if [ $? -eq 0 ] ; then
                logger -t NAT6 "Added IPv6 masquerading rule to the firewall (Src: $LAN_ULA_PREFIX - Dst: $WAN6_INTERFACE)"
        else
                logger -t NAT6 "Fatal error: Failed to add IPv6 masquerading rule to the firewall (Src: $LAN_ULA_PREFIX - Dst: $WAN6_INTERFACE)" && exit 1
        fi
 
        route -A inet6 add 2000::/3 gw "$WAN6_GATEWAY" dev "$WAN6_INTERFACE"
        if [ $? -eq 0 ] ; then
                logger -t NAT6 "Added $WAN6_GATEWAY to routing table as gateway on $WAN6_INTERFACE for outgoing connections"
        else
                logger -t NAT6 "Error: Failed to add $WAN6_GATEWAY to routing table as gateway on $WAN6_INTERFACE for outgoing connections"
        fi
 
        if [ $PRIVACY -eq 1 ] ; then
                echo 2 > "/proc/sys/net/ipv6/conf/$WAN6_INTERFACE/accept_ra"
                if [ $? -eq 0 ] ; then
                        logger -t NAT6 "Accepting router advertisements on $WAN6_INTERFACE even if forwarding is enabled (required for temporary addresses)"
                else
                        logger -t NAT6 "Error: Failed to change router advertisements accept policy on $WAN6_INTERFACE (required for temporary addresses)"
                fi
                echo 2 > "/proc/sys/net/ipv6/conf/$WAN6_INTERFACE/use_tempaddr"
                if [ $? -eq 0 ] ; then
                        logger -t NAT6 "Using temporary addresses for outgoing connections on interface $WAN6_INTERFACE"
                else
                        logger -t NAT6 "Error: Failed to enable temporary addresses for outgoing connections on interface $WAN6_INTERFACE"
                fi
        fi
 
        exit 0
}

键盘按Esc键，并输入:wq，按回车

终端输入chmod +x /etc/init.d/nat6 && /etc/init.d/nat6 enable，按回车

防火墙配置Allow-ICMPv6-Forward

终端输入uci set firewall.@rule["$(uci show firewall | grep 'Allow-ICMPv6-Forward' | cut -d'[' -f2 | cut -d']' -f1)"].enabled='0' && uci commit firewall，按回车。

接收广播并开启IPv6转发

终端输入vi /etc/sysctl.conf，按回车。

按键盘I键，把文件中相关内容改为以下内容，没有的话就添加。

net.ipv6.conf.default.forwarding=2 
net.ipv6.conf.all.forwarding=2 
net.ipv6.conf.default.accept_ra=2 
net.ipv6.conf.all.accept_ra=2

键盘按Esc键，并输入:wq，按回车。

加入转发规则

终端输入vi /etc/firewall.user，按回车。

按键盘I键，添加一行。

ip6tables -t nat -I POSTROUTING -s $(uci get network.globals.ula_prefix) -j MASQUERADE

键盘按Esc键，并输入:wq，按回车。

重启路由器

终端输入reboot，按回车。

常见问题

如果中途遇到错误，请回头检查一下是否复制完整。

参考资料：

1. https://www.lolimay.cn/2018/07/09/openwrt-nat6/