概述

在PPPoE拨号场景下，通过DHCP获取IPv6前缀，并进行stateless地址分配。

环境准备

软件安装

apt update
apt install wide-dhcpv6-client pppoeconf radvd

防火墙配置

*filter
:INPUT DROP [528:90495]
:FORWARD DROP [3:192]
:OUTPUT ACCEPT [2345:216964]
-A INPUT -p udp -m multiport --sports 546,547 -j ACCEPT
-A INPUT -p ipv6-icmp -j ACCEPT
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT ! -i ppp0 -j ACCEPT
-A FORWARD -p icmp -j ACCEPT
-A FORWARD -p ipv6-icmp -j ACCEPT
-A FORWARD -p icmp -j ACCEPT
-A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
-A FORWARD ! -i ppp0 -j ACCEPT
COMMIT

PPPoE 拨号配置

终端输入pppoeconf按照提示进行PPPoE拨号。

pppoeconf

编辑/etc/ppp/peers/dsl-provider配置文件，添加以下配置开启IPv6功能。

...
+ipv6
...

查看/etc/network/interfaces,可以看到pppoe拨号的相关配置，可以使用ifup/ifdown命令启停dsl-provider。

auto dsl-provider
iface dsl-provider inet ppp
    pre-up /bin/ip link set eth0 up # line maintained by pppoeconf
    provider dsl-provider

DHCPv6 PD

配置DHCPv6 Client,用于获取PD前缀和配置LAN口IPv6地址
/etc/wide-dhcpv6/dhcp6c.conf

profile default
{
  information-only;
  request domain-name-servers;
  request domain-name;
  script "/etc/wide-dhcpv6/dhcp6c-script";
};

interface ppp0 {
  send ia-pd 0;
};

id-assoc pd {
  prefix ::/64 infinity;
  prefix-interface eth1 {
    sla-len 0;
    ifid 1;
  };
};

注意： sla-len应设置为满足(WAN-prefix) + (sla-len) = 64的值。这里示范的情况是针对一个长度/56的前缀，56+8=64。对于前缀长度/64的网络，sla-len应为0。

配置ifup脚本

在ppp拨号成功，获取IPv6地址后，自动更新前缀和LAN网卡IP

touch /etc/ppp/ipv6-up.d/assign_ipv6_address
chmod +x /etc/ppp/ipv6-up.d/assign_ipv6_address

写入以下脚本，将eth1修改为对应LAN网卡即可

#!/bin/sh
# ppp.ip-up hook script for ipv6

LAN_IFACE="eth1"
LOCAL_ADDR=`ip addr show ${LAN_IFACE} to fe80::/64 | grep inet6 | awk  '{print $2}'`
ip -6 addr flush ${LAN_IFACE}
ip addr add  ${LOCAL_ADDR} dev ${LAN_IFACE}
systemctl restart wide-dhcpv6-client.service

Radvd配置

配置radvd，并通过stateless模式分配IPv6地址。

cat >/etc/radvd.conf <<EOF
interface eth1 {
   AdvSendAdvert on;
   MinRtrAdvInterval 3;
   MaxRtrAdvInterval 10;
   prefix ::/64 {
     AdvOnLink on;
     AdvAutonomous on;
     AdvRouterAddr on;
     AdvValidLifetime 120;
     AdvPreferredLifetime 120;
   };
};
EOF