# IPv6 (简体中文)

Summary help replacing me
This article covers IPv6, and basics of configuring different IPv6 related things like static IP adresses.
Related
IPv6 - Tunnel Broker Setup

翻译状态： 本文是英文页面 IPv6 的翻译，最后翻译时间：2013-03-05，点击这里可以查看翻译后英文页面的改动。

在Arch Linux, IPv6默认是打开的。如果你要找IPv6隧道的资料，可以看 IPv6 - Tunnel Broker Setup.

## Privacy Extensions

To enable Privacy Extensions for Stateless Address Autoconfiguration in IPv6 according to RFC 4941, reproduce the following steps:

Add these lines to `/etc/sysctl.d/40-privacy-extension.conf`::

    # Enable IPv6 Privacy Extensions
    net.ipv6.conf.all.use_tempaddr = 2
    net.ipv6.conf.default.use_tempaddr = 2
    net.ipv6.conf.<nic0>.use_tempaddr = 2
    ...
    net.ipv6.conf.<nicN>.use_tempaddr = 2

Where <nic0> to <nicN> are your nic's (the "all" or "default" parameters do not apply to nic's that already exist when the sysctl settings are applied).

After a reboot, at the latest, Privacy Extensions should be enabled.

## Neighbor Discovery

Pinging the multicast address `ff02::1` results in all hosts in link-local scope responding. An interface has to be specified. With a ping to the multicast address `ff02::2` only routers will respond.

    $ ping6 ff02::1%eth0

If you add an option `-I <your-global-ipv6>`, link-local hosts will respond with their link-global scope addresses. The interface can be omitted in this case.

    $ ping6 -I 2001:4f8:fff6::21 ff02::1

## 静态地址

Sometime using static address can improve security. For example, if your local router uses Neighbor Discovery or radvd (RFC 2461), your interface will automatically be assigned an address based its MAC address (using IPv6's Stateless Autoconfiguration). This may be less than ideal for security since it allows a system to be tracked even if the network portion of the IP address changes.

To assign a static address (for example `2001:470:1000:1000::5/64`):

Add your static IP using `netcfg`. Follow the netcfg article. When copying an example use `ethernet-static` and modify it like so:

    CONNECTION='ethernet'
    DESCRIPTION='ipv6+ipv4 eth0'
    INTERFACE='eth0'

    IP=static
    ADDR=192.168.1.5
    NETMASK=24
    ROUTES=
    GATEWAY=192.168.1.1

    IP6=static
    ADDR6=(2001:470:1000:1000::5/64)
    GATEWAY6=2001:470:1000:1000::1

## 禁用 IPv6

禁用 IPv6 据称可以加速网络访问速度，因为在不支持 IPv6 的网络上程序也会试图使用它来访问。另外说一句, Firefox 也在受影响的程序列表中。在 IPv6 广泛采用之前，我们可以通过禁用它受益。

许多人并不需要这个特性，屏蔽它可以增加性能（许多程序会首先查询IPv6地址，不管你是否有IPv6连接）。

## 禁用 IPv6

Note: The Arch kernel has IPv6 support built in directly [1], therefore a module cannot be blacklisted.

### Disable functionality

Adding `ipv6.disable=1` to the kernel line disables the whole IPv6 stack, which is likely what you want if you are experiencing issues. See Kernel parameters for more information.

Alternatively, adding `ipv6.disable_ipv6=1` instead will keep the IPv6 stack functional but will not assign IPv6 addresses to any of your network devices.

One can also avoid assigning IPv6 addresses to specific network interfaces by adding the following sysctl config to `/etc/sysctl.d/ipv6.conf`:

    # Disable IPv6
    net.ipv6.conf.all.disable_ipv6 = 1
    net.ipv6.conf.<interface0>.disable_ipv6 = 1
    ...
    net.ipv6.conf.<interfaceN>.disable_ipv6 = 1

Note that you must list all of the targeted interfaces explicitly, as disabling "all" does not apply to interfaces that are already "up" when sysctl settings are applied.

Note 2, if disabling IPv6 by sysctl, you should comment out the IPv6 hosts in your `/etc/hosts`-file.

    #<ip-address>	<hostname.domain.org>	<hostname>
    127.0.0.1	localhost.localdomain	localhost
    #::1		localhost.localdomain	localhost

otherwise there could be some connection errors because hosts are resolved to there IPv6 address which is not reachable.

### Other programs

Disabling IPv6 functionality in the kernel does not prevent other programs from trying to use IPv6. In most cases, this is completely harmless, but if you find yourself having issues with that program, you should consult the program's manpages for a way to disable that functionality.

For instance, dhcpcd will continue to harmlessly attempt to perform IPv6 router solicitation. To disable this, as stated in the dhcpcd.conf manpage, add the following to `/etc/dhcpcd.conf`:

    noipv6rs

## 附加资源

- ipv6 - kernel.org 文档库

Category:

- Networking (简体中文)