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.. _nat66:
############
NAT66(NPTv6)
############
:abbr:`NPTv6 (IPv6-to-IPv6 Network Prefix Translation)` is an address
translation technology based on IPv6 networks, used to convert an IPv6
address prefix in an IPv6 message into another IPv6 address prefix.
We call this address translation method NAT66. Devices that support the NAT66
function are called NAT66 devices, which can provide NAT66 source
and destination address translation functions.
Overview
========
Different NAT Types
-------------------
.. _source-nat66:
SNAT66
^^^^^^
:abbr:`SNPTv6 (Source IPv6-to-IPv6 Network Prefix Translation)` The conversion
function is mainly used in the following scenarios:
* A single internal network and external network. Use the NAT66 device to
connect a single internal network and public network, and the hosts in
the internal network use IPv6 address prefixes that only support
routing within the local range. When a host in the internal network
accesses the external network, the source IPv6 address prefix in
the message will be converted into a global unicast IPv6 address
prefix by the NAT66 device.
* Redundancy and load sharing. There are multiple NAT66 devices at the edge
of an IPv6 network to another IPv6 network. The path through the NAT66
device to another IPv6 network forms an equivalent route, and traffic
can be load-shared on these NAT66 devices. In this case, you
can configure the same source address translation rules on these
NAT66 devices, so that any NAT66 device can handle IPv6 traffic between
different sites.
* Multi-homed. In a multi-homed network environment, the NAT66 device
connects to an internal network and simultaneously connects to
different external networks. Address translation can be configured
on each external network side interface of the NAT66 device to
convert the same internal network address into different external
network addresses, and realize the mapping of the same internal
address to multiple external addresses.
.. _destination-nat66:
DNAT66
^^^^^^
The :abbr:`DNPTv6 (Destination IPv6-to-IPv6 Network Prefix Translation)`
destination address translation function is used in scenarios where the
server in the internal network provides services to the external network,
such as providing Web services or FTP services to the external network.
By configuring the mapping relationship between the internal server
address and the external network address on the external network
side interface of the NAT66 device, external network users can
access the internal network server through the designated
external network address.
Prefix Conversion
------------------
Source Prefix
^^^^^^^^^^^^^
Every SNAT66 rule has a translation command defined. The prefix defined
for the translation is the prefix used when the address information in
a packet is replaced.、
The :ref:`source-nat66` rule replaces the source address of the packet
and calculates the converted address using the prefix specified in the rule.
Example:
* Convert the address prefix of a single `fc01::/64` network to `fc00::/64`
* Output from `eth0` network interface
.. code-block:: none
set nat66 source rule 1 outbound-interface name 'eth0'
set nat66 source rule 1 source prefix 'fc01::/64'
set nat66 source rule 1 translation address 'fc00::/64'
Destination Prefix
^^^^^^^^^^^^^^^^^^
For the :ref:`destination-nat66` rule, the destination address of
the packet isreplaced by the address calculated from the specified
address or prefix in the `translation address` command
Example:
* Convert the address prefix of a single `fc00::/64` network
to `fc01::/64`
* Input from `eth0` network interface
.. code-block:: none
set nat66 destination rule 1 inbound-interface name 'eth0'
set nat66 destination rule 1 destination address 'fc00::/64'
set nat66 destination rule 1 translation address 'fc01::/64'
Configuration Examples
======================
Use the following topology to build a nat66 based isolated
network between internal and external networks (dynamic prefix is
not supported):
.. figure:: /_static/images/vyos_1_4_nat66_simple.png
:alt: VyOS NAT66 Simple Configure
R1:
.. code-block:: none
set interfaces ethernet eth0 ipv6 address autoconf
set interfaces ethernet eth1 address 'fc01::1/64'
set nat66 destination rule 1 destination address 'fc00:470:f1cd:101::/64'
set nat66 destination rule 1 inbound-interface name 'eth0'
set nat66 destination rule 1 translation address 'fc01::/64'
set nat66 source rule 1 outbound-interface name 'eth0'
set nat66 source rule 1 source prefix 'fc01::/64'
set nat66 source rule 1 translation address 'fc00:470:f1cd:101::/64'
R2:
.. code-block:: none
set interfaces bridge br1 address 'fc01::2/64'
set interfaces bridge br1 member interface eth0
set interfaces bridge br1 member interface eth1
set protocols static route6 ::/0 next-hop fc01::1
set service router-advert interface br1 prefix ::/0
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