IPv4/IPv6 过渡技术

See also: NAT64 for IPv6-only networks, NAT66 and IPv6 masquerading, IPv6 NAT and NPT

可以使用以下软件包安装过渡技术：

• IPv6-in-IPv4 隧道: 6rd, 6to4, 6in4.
• IPv4-in-IPv6 隧道: ds-lite.

See also: Setting up an IPv6 Tunnel with LuCI, IPv6 with Hurricane Electric

6in4 隧道通常由像 HE.net 这样的外部隧道提供商提供。

The package 6in4 must be installed to use this protocol.

6in4要求您具有公网IPv4-地址, 不支持ISP NAT后的客户端。

下面的示例演示了 Hurricane Electric (he.net) 代理服务商的静态隧道配置. 设定 ipaddr 指定本地IPv4地址, peeraddr 是代理IPv4地址和 ip6addr 是通过隧道路由的本地IPv6地址。

# /etc/config/network
config interface 'wan6'
        option proto     '6in4'
        option ipaddr    '178.24.115.19'
        option peeraddr  '216.66.80.30'
        option ip6addr   '2001:0DB8:1f0a:1359::2/64'

下面的示例演示了启用IP更新的 Hurricane Electric (he.net) 代理的动态隧道配置。本地IPv4地址是自动确定的。选项 tunnelid, username and updatekey 用于IP更新。

# /etc/config/network
config interface 'wan6'
        option proto     '6in4'
        option mtu       '1424'                      # IPv6 隧道 MTU（可选） 
        option peeraddr  '216.66.80.30'              # 隧道提供商处的 IPv4 隧道端点
        option ip6addr   '2001:0db8:1f0a:1359::2/64' # IPv6 隧道地址
        option ip6prefix '2001:db8:1234::/48'        # 您的路由前缀（必需）
        # 下面的配置选项仅对 HE.net 隧道有效，对于其他隧道提供商，请忽略它们。
        option tunnelid  '12345'                     # HE.net隧道id
        option username  'username'                  # HE.net username used to login into tunnelbroker, not the User ID shown after login in.
        option updatekey 'updatekey'                 # HE.net updatekey instead of password, default for new tunnels

See below for advanced configuration options.

In a typical tunnel configuration (e.g. HE.net) you get two different ipv6 addresses/prefixes from the tunnel provider:

• ip6addr: The tunnel endpoint address is like '2001:DB8:2222:EFGH::2/64'. This ...::2 address is only used for the tunnel interface endpoint. It is not a routable address and it can't be used for anything else than connecting to the other end of the tunnel, typically ...::1 .
• ip6prefix: The tunnel provider gives you also a routable prefix, typically either /48 or /64, for example '2001:DB8:1112::/48' or '2001:DB8:1234:ABCD::/64'. Your LAN clients will get addresses from that prefix. Using a wider prefix helps delegate IPv6 to several downstream networks.

Some users may require to add extra firewall rules to allow 6in4 traffic to always reach their tunnel endpoint. The package iptables-mod-ipopt must be installed for length matching.

# /etc/config/firewall
config rule
        option name      'Allow-protocol-41'
        option src       'wan'
        option proto     '41'
        option target    'ACCEPT'
 
config rule
        option name      'Allow-protocol-59'
        option src       'wan'
        option proto     '59'
        option target    'ACCEPT'
        option extra     '-m length --length 40'

Provide default route to override sourcefilter.

# /etc/config/network
config route6
        option interface 'wan6'
        option target    '::/0'

This protocol type does not need the device option set in the interface section. The interface name is derived from the section name, e.g. config interface sixbone would result in an interface named 6in4-sixbone.

Although ip6prefix isn't required, sourcefilter is enabled by default and prevents forwarding of packets unless ip6prefix is specified.

6rd 是基于 6to4 的隧道机制。与其他隧道机制不同，6rd 通常由 ISP 本身提供。

必须安装 6rd 包才能使用此协议。

6rd 的配置通常是自动检测的，不需要手动配置，只需安装 6rd 软件包（并重新启动）通常就足够了。

To automatically configure 6rd from dhcp you need to create an interface with option auto 0 and put its name as the 'iface6rd' parameter. In addition you also need to add its name to a suitable firewall zone in /etc/config/firewall.

# /etc/config/network
config interface 'wan6'
        option proto '6rd'
        option peeraddr '77.174.0.2'
        option ip6prefix '2001:838:ad00::'
        option ip6prefixlen '40'
        option ip4prefixlen '16'

To debug 6rd via DHCP, enable DHCP client logging, reboot the router, and check the logs:

# logread -e ip6rd
ip6rd=16 40 2001:0838:ad00:0000:0000:0000:0000:0000 77.174.0.2

If this line isn't present, you need to obtain the correct values for peeraddr, ip6prefix, ip6prefixlen and ip4prefixlen from your ISP. The above ip6rd or the obtained values can be used to hardcode the 6rd tunnel. Remove or comment out the iface6rd line in the wan section.

If you choose a name for your tunnel-interface different from wan6, be sure to add that network to the wan firewall-zone.

Below configuration options are only needed for hardcoding the 6rd tunnel.

This protocol type does not need the device option set in the interface section. The interface name is derived from the section name, e.g. config interface wan6 would result in an interface named 6rd-wan6.

Some ISP's give you the number of bytes you should use from your WAN IP to calculate your IPv6 address. ip4prefixlen expects the prefix bytes of your WAN IP to calculate the IPv6 address. So if your ISP gives you 14 bytes to calculate, enter 18 (32 - 14).

This is another transitional mechanism for IPv6 used by some ISPs, it relies on a L2TPv2 tunnel.

The package xl2tpd must be installed to use this protocol. It will handle the L2TP tunnel and PPP session.

The high-level description of the tunneling is the following:

1. An L2TP tunnel is created, encapsulated in UDP packets over IPv4.
2. A PPP session is established inside the tunnel.
3. IPv6CP (see RFC 5072) is used to negotiate link-local IPv6 addresses.
4. An IPv6 prefix is obtained thanks to DHCPv6.

This howto is derived from an experience with SFR, in France (FTTH residential access). It might apply to other ISPs as well. In the case of SFR, steps 1 and 2 require an authentication. Fortunately, the L2TP password is hardcoded. The PPP password is not, but it's sent as cleartext, so a simple sniffing is enough to recover it.

# /etc/config/network
config interface 6pe
        option proto l2tpv2
        option server <LNS address>
        option username '<PPP username>'
        option password '<PPP password>'
        option keepalive '6'
        option ipv6 '1'
 
config interface 'wan6'
        option device '@6pe'
        option proto 'dhcpv6'

If you need authentication at the L2TP level (before PPP):

# /etc/xl2tpd/xl2tp-secrets
* * my_l2tp_password

At this point, running service network reload or simply running ifup wan6 should give you a fully working IPv6 setup. To debug, look at the logs (logread) and the interfaces status (ifstatus 6pe and ifstatus wan6).

请参阅下文了解高级配置选项。

Most options are similar to protocol “ppp”.

The name of the physical interface will be “l2tp-<logical interface name>”.

6to4 is the simplest IPv6 tunneling mechanism and relies on publicly available gateways.

必须安装软件包 6to4 才能使用此协议。

# /etc/config/network
config interface 'wan6'
        option proto '6to4'
 
# /etc/config/firewall
config rule
        option target 'ACCEPT' 
        option name '6to4' 
        option src 'wan' 
        option proto '41'

If you choose a name for your tunnel-interface different from wan6, be sure to add that network to the wan firewall-zone.

请参阅下文了解高级配置选项。

This protocol type does not need the device option set in the interface section. The interface name is derived from the section name, e.g. config interface wan6 would result in an interface named 6to4-wan6.

ds-lite is a transitioning-mechanism which is used by ISPs to support legacy IPv4-connectivity over a native IPv6 connection.

必须安装 ds-lite 软件包才能使用此协议。

配置通常是自动检测的，不需要手动配置，只需安装 ds-lite 软件包（并像更改配置时那样重新启动网络接口）通常就足够了。

# /etc/config/network
config interface 'wan6'
        option ifname 'eth1'
        option proto 'dhcpv6'
 
config interface 'wan'
        option proto 'dslite'
        option peeraddr '2001:db80::1' # Your ISP's DS-Lite AFTR

If you choose a name for your tunnel-interface that is different from 'wan' make sure to add that name to the network-option of the firewall-zone 'wan' in /etc/config/firewall.

请参阅下文了解高级配置选项。

ds-lite 操作要求禁用IPv4 NAT。 您应该相应地调整 /etc/config/firewall 中的设置。

This protocol type does not need an ifname option set in the interface section. The interface name is derived from the section name, e.g. config interface wan would result in an interface named dslite-wan.