IPv6, successor to IPv4, is a newer version of the IP protocol designed to fix its flaws, most notably the scarcity of available IP addresses. This protocol handles the network layer; its purpose is to provide a way to address machines, to convey data to their intended destination, and to handle data fragmentation if needed (in other words, to split packets into chunks with a size that depends on the network links to be used on the path and to reassemble the chunks in their proper order on arrival).
В ядра Debian включена обработка IPv6 внутри самого ядра (за исключением нескольких архитектур устройств, в которых скомпилирован модуль, называемый ipv6). Основные инструменты, такие как ping и traceroute, имеют их IPv6 эквивалентов, называемых ping6 и traceroute6, которые доступны в пакетах с соответствующими именами iputils-ping и iputils-tracepath.
Сеть IPv6 настраивается аналогично тому, как это делается в IPv4, в файле /etc/network/interfaces. Но если вы хотите, чтобы сеть была доступна глобально, вы должны убедиться, что имеете IPv6-совместимый маршрутизатор, перенаправляющий трафик в глобальную IPv6 сеть.
Пример 10.10. Пример настройки IPv6
iface enp7s0 inet6 static
address 2001:db8:1234:5::1:1/64
# Disabling auto-configuration
# autoconf 0
# The router is auto-configured and has no fixed address
# (accept_ra 1). If it had:
# gateway 2001:db8:1234:5::1
Подсети IPv6 обычно имеют сетевую маску в 64 бита. Из этого следует, что внутри подсетей может существовать до 2
64 различных адресов. Это позволяет делать автонастройку выдачи адресов для машин в подсетях на основе MAC-адреса сетевого интерфейса ("Stateless Address Autoconfiguration" или коротко
SLAAC). По умолчанию, если
SLAAC активирован в вашей сети и IPv6 есть на вашем компьютере, то ядро автоматически найдёт IPv6 маршрутизаторы и настроит сетевые интерфейсы.
This behavior may have privacy implications. If you switch networks frequently, e.g. with a laptop, you might not want your
MAC address being a part of your public IPv6 address. This makes it easy to identify the same device across networks. A solution to this are IPv6 privacy extensions (which Debian enables by default if IPv6 connectivity is detected during initial installation), which will assign an additional randomly generated address to the interface, periodically change them and prefer them for outgoing connections. Incoming connections can still use the address generated by SLAAC. The following example, for use in
/etc/network/interfaces, activates these privacy extensions for the interface
enp7s0.
Пример 10.11. Расширения секретности IPv6
iface enp7s0 inet6 auto
# Prefer the randomly assigned addresses for outgoing connections.
privext 2
IPv6 connections can be restricted, in the same fashion as for IPv4.
nft can be used to create firewall rules for IPv4 and IPv6 (see
Раздел 14.2.3, «Syntax of nft»).
If a native IPv6 connection is not available, the fallback method is to use a tunnel over IPv4. Hurricane Electric is one (free) provider of such tunnels:
To use a Hurricane Electric tunnel, you need to register an account, login, select a free tunnel and edit the file /etc/network/interfaces with the generated code.
You can install and configure the radvd daemon (from the similarly-named package) if you want to use the configured computer as a router for a local network. This IPv6 configuration daemon has a role similar to dhcpd in the IPv4 world.
The /etc/radvd.conf configuration file must then be created (see /usr/share/doc/radvd/examples/simple-radvd.conf as a starting point). In our case, the only required change is the prefix, which needs to be replaced with the one provided by Hurricane Electric; it can be found in the output of the ip a command, in the block concerning the he-ipv6 interface.
Then run systemctl start radvd. The IPv6 network should now work.
