.. _network_config_v2:

Networking Config Version 2

===========================

Cloud-init's support for Version 2 network config is a subset of the

version 2 format defined for the `netplan`_ tool.  Cloud-init supports

both reading and writing of Version 2; the latter support requires a

distro with `netplan`_ present.

The ``network`` key has at least two required elements.  First

it must include ``version: 2``  and one or more of possible device

``types``..

Cloud-init will read this format from system config.

For example the following could be present in

``/etc/cloud/cloud.cfg.d/custom-networking.cfg``::

  network:

    version: 2

    ethernets: []

It may also be provided in other locations including the

:ref:`datasource_nocloud`, see :ref:`default_behavior` for other places.

Supported device ``types`` values are as follows:

- Ethernets (``ethernets``)

- Bonds (``bonds``)

- Bridges (``bridges``)

- VLANs (``vlans``)

Each type block contains device definitions as a map where the keys (called

"configuration IDs"). Each entry under the ``types`` may include IP and/or

device configuration.

Cloud-init does not current support ``wifis`` type that is present in native

`netplan`_.

Device configuration IDs

------------------------

The key names below the per-device-type definition maps (like ``ethernets:``)

are called "ID"s. They must be unique throughout the entire set of

configuration files. Their primary purpose is to serve as anchor names for

composite devices, for example to enumerate the members of a bridge that is

currently being defined.

There are two physically/structurally different classes of device definitions,

and the ID field has a different interpretation for each:

Physical devices

:   (Examples: ethernet, wifi) These can dynamically come and go between

    reboots and even during runtime (hotplugging). In the generic case, they

    can be selected by ``match:`` rules on desired properties, such as

    name/name pattern, MAC address, driver, or device paths. In general these

    will match any number of devices (unless they refer to properties which are

    unique such as the full path or MAC address), so without further knowledge

    about the hardware these will always be considered as a group.

    It is valid to specify no match rules at all, in which case the ID field is

    simply the interface name to be matched. This is mostly useful if you want

    to keep simple cases simple, and it's how network device configuration has

    been done for a long time.

    If there are ``match``: rules, then the ID field is a purely opaque name

    which is only being used  for references from definitions of compound

    devices in the config.

Virtual devices

:  (Examples: veth, bridge, bond) These are fully under the control of the

   config file(s) and the network stack. I. e. these devices are being created

   instead of matched. Thus ``match:`` and ``set-name:`` are not applicable for

   these, and the ID field is the name of the created virtual device.

Common properties for physical device types

-------------------------------------------

**match**: *<(mapping)>*

This selects a subset of available physical devices by various hardware

properties. The following configuration will then apply to all matching

devices, as soon as they appear. *All* specified properties must match.

The following properties for creating matches are supported:

**name**:  *<(scalar)>*

Current interface name. Globs are supported, and the primary use case

for matching on names, as selecting one fixed name can be more easily

achieved with having no ``match:`` at all and just using the ID (see

above). Note that currently only networkd supports globbing,

NetworkManager does not.

**macaddress**: *<(scalar)>*

Device's MAC address in the form "XX:XX:XX:XX:XX:XX". Globs are not allowed.

**driver**: *<(scalar)>*

Kernel driver name, corresponding to the ``DRIVER`` udev property.  Globs are

supported. Matching on driver is *only* supported with networkd.

**Examples**::

  # all cards on second PCI bus

  match:

    name: enp2*

  # fixed MAC address

  match:

    macaddress: 11:22:33:AA:BB:FF

  # first card of driver ``ixgbe``

  match:

    driver: ixgbe

    name: en*s0

**set-name**: *<(scalar)>*

When matching on unique properties such as path or MAC, or with additional

assumptions such as "there will only ever be one wifi device",

match rules can be written so that they only match one device. Then this

property can be used to give that device a more specific/desirable/nicer

name than the default from udev’s ifnames.  Any additional device that

satisfies the match rules will then fail to get renamed and keep the

original kernel name (and dmesg will show an error).

**wakeonlan**: *<(bool)>*

Enable wake on LAN. Off by default.

Common properties for all device types

--------------------------------------

**renderer**: *<(scalar)>*

Use the given networking backend for this definition. Currently supported are

``networkd`` and ``NetworkManager``. This property can be specified globally

in ``networks:``, for a device type (in e. g. ``ethernets:``) or

for a particular device definition. Default is ``networkd``.

.. note::

  Cloud-init only supports networkd backend if rendering version2 config

  to the instance.

**dhcp4**: *<(bool)>*

Enable DHCP for IPv4. Off by default.

**dhcp6**: *<(bool)>*

Enable DHCP for IPv6. Off by default.

**addresses**: *<(sequence of scalars)>*

Add static addresses to the interface in addition to the ones received

through DHCP or RA. Each sequence entry is in CIDR notation, i. e. of the

form ``addr/prefixlen`` . ``addr`` is an IPv4 or IPv6 address as recognized

by ``inet_pton``(3) and ``prefixlen`` the number of bits of the subnet.

Example: ``addresses: [192.168.14.2/24, 2001:1::1/64]``

**gateway4**: or **gateway6**: *<(scalar)>*

Set default gateway for IPv4/6, for manual address configuration. This

requires setting ``addresses`` too. Gateway IPs must be in a form

recognized by ``inet_pton(3)``

Example for IPv4: ``gateway4: 172.16.0.1``

Example for IPv6: ``gateway6: 2001:4::1``

**mtu**: *<MTU SizeBytes>*

The MTU key represents a device's Maximum Transmission Unit, the largest size

packet or frame, specified in octets (eight-bit bytes), that can be sent in a

packet- or frame-based network.  Specifying ``mtu`` is optional.

**nameservers**: *<(mapping)>*

Set DNS servers and search domains, for manual address configuration. There

are two supported fields: ``addresses:`` is a list of IPv4 or IPv6 addresses

similar to ``gateway*``, and ``search:`` is a list of search domains.

Example: ::

  nameservers:

    search: [lab, home]

    addresses: [8.8.8.8, FEDC::1]

**routes**: *<(sequence of mapping)>*

Add device specific routes.  Each mapping includes a ``to``, ``via`` key

with an IPv4 or IPv6 address as value.  ``metric`` is an optional value.

Example: ::

  routes:

   - to: 0.0.0.0/0

     via: 10.23.2.1

     metric: 3

Ethernets

~~~~~~~~~

Ethernet device definitions do not support any specific properties beyond the

common ones described above.

Bonds

~~~~~

**interfaces** *<(sequence of scalars)>*

All devices matching this ID list will be added to the bond.

Example: ::

  ethernets:

    switchports:

      match: {name: "enp2*"}

  [...]

  bonds:

    bond0:

      interfaces: [switchports]

**parameters**: *<(mapping)>*

Customization parameters for special bonding options.  Time values are

specified in seconds unless otherwise specified.

**mode**: *<(scalar)>*

Set the bonding mode used for the interfaces. The default is

``balance-rr`` (round robin). Possible values are ``balance-rr``,

``active-backup``, ``balance-xor``, ``broadcast``, ``802.3ad``,

``balance-tlb``, and ``balance-alb``.

**lacp-rate**: *<(scalar)>*

Set the rate at which LACPDUs are transmitted. This is only useful

in 802.3ad mode. Possible values are ``slow`` (30 seconds, default),

and ``fast`` (every second).

**mii-monitor-interval**: *<(scalar)>*

Specifies the interval for MII monitoring (verifying if an interface

of the bond has carrier). The default is ``0``; which disables MII

monitoring.

**min-links**: *<(scalar)>*

The minimum number of links up in a bond to consider the bond

interface to be up.

**transmit-hash-policy**: <*(scalar)>*

Specifies the transmit hash policy for the selection of slaves. This

is only useful in balance-xor, 802.3ad and balance-tlb modes.

Possible values are ``layer2``, ``layer3+4``, ``layer2+3``,

``encap2+3``, and ``encap3+4``.

**ad-select**: <*(scalar)>*

Set the aggregation selection mode. Possible values are ``stable``,

``bandwidth``, and ``count``. This option is only used in 802.3ad mode.

**all-slaves-active**: <*(bool)>*

If the bond should drop duplicate frames received on inactive ports,

set this option to ``false``. If they should be delivered, set this

option to ``true``. The default value is false, and is the desirable

behavior in most situations.

**arp-interval**: <*(scalar)>*

Set the interval value for how frequently ARP link monitoring should

happen. The default value is ``0``, which disables ARP monitoring.

**arp-ip-targets**: <*(sequence of scalars)>*

IPs of other hosts on the link which should be sent ARP requests in

order to validate that a slave is up. This option is only used when

``arp-interval`` is set to a value other than ``0``. At least one IP

address must be given for ARP link monitoring to function. Only IPv4

addresses are supported. You can specify up to 16 IP addresses. The

default value is an empty list.

**arp-validate**: <*(scalar)>*

Configure how ARP replies are to be validated when using ARP link

monitoring. Possible values are ``none``, ``active``, ``backup``,

and ``all``.

**arp-all-targets**: <*(scalar)>*

Specify whether to use any ARP IP target being up as sufficient for

a slave to be considered up; or if all the targets must be up. This

is only used for ``active-backup`` mode when ``arp-validate`` is

enabled. Possible values are ``any`` and ``all``.

**up-delay**: <*(scalar)>*

Specify the delay before enabling a link once the link is physically

up. The default value is ``0``.

**down-delay**: <*(scalar)>*

Specify the delay before disabling a link once the link has been

lost. The default value is ``0``.

**fail-over-mac-policy**: <*(scalar)>*

Set whether to set all slaves to the same MAC address when adding

them to the bond, or how else the system should handle MAC addresses.

The possible values are ``none``, ``active``, and ``follow``.

**gratuitious-arp**: <*(scalar)>*

Specify how many ARP packets to send after failover. Once a link is

up on a new slave, a notification is sent and possibly repeated if

this value is set to a number greater than ``1``. The default value

is ``1`` and valid values are between ``1`` and ``255``. This only

affects ``active-backup`` mode.

**packets-per-slave**: <*(scalar)>*

In ``balance-rr`` mode, specifies the number of packets to transmit

on a slave before switching to the next. When this value is set to

``0``, slaves are chosen at random. Allowable values are between

``0`` and ``65535``. The default value is ``1``. This setting is

only used in ``balance-rr`` mode.

**primary-reselect-policy**: <*(scalar)>*

Set the reselection policy for the primary slave. On failure of the

active slave, the system will use this policy to decide how the new

active slave will be chosen and how recovery will be handled. The

possible values are ``always``, ``better``, and ``failure``.

**learn-packet-interval**: <*(scalar)>*

Specify the interval between sending learning packets to each slave.

The value range is between ``1`` and ``0x7fffffff``. The default

value is ``1``. This option only affects ``balance-tlb`` and

``balance-alb`` modes.

Bridges

~~~~~~~

**interfaces**: <*(sequence of scalars)>*

All devices matching this ID list will be added to the bridge.

Example: ::

  ethernets:

    switchports:

      match: {name: "enp2*"}

  [...]

  bridges:

    br0:

      interfaces: [switchports]

**parameters**: <*(mapping)>*

Customization parameters for special bridging options.  Time values are

specified in seconds unless otherwise specified.

**ageing-time**: <*(scalar)>*

Set the period of time to keep a MAC address in the forwarding

database after a packet is received.

**priority**: <*(scalar)>*

Set the priority value for the bridge. This value should be an

number between ``0`` and ``65535``. Lower values mean higher

priority. The bridge with the higher priority will be elected as

the root bridge.

**forward-delay**: <*(scalar)>*

Specify the period of time the bridge will remain in Listening and

Learning states before getting to the Forwarding state. This value

should be set in seconds for the systemd backend, and in milliseconds

for the NetworkManager backend.

**hello-time**: <*(scalar)>*

Specify the interval between two hello packets being sent out from

the root and designated bridges. Hello packets communicate

information about the network topology.

**max-age**: <*(scalar)>*

Set the maximum age of a hello packet. If the last hello packet is

older than that value, the bridge will attempt to become the root

bridge.

**path-cost**: <*(scalar)>*

Set the cost of a path on the bridge. Faster interfaces should have

a lower cost. This allows a finer control on the network topology

so that the fastest paths are available whenever possible.

**stp**: <*(bool)>*

Define whether the bridge should use Spanning Tree Protocol. The

default value is "true", which means that Spanning Tree should be

used.

VLANs

~~~~~

**id**: <*(scalar)>*

VLAN ID, a number between 0 and 4094.

**link**: <*(scalar)>*

ID of the underlying device definition on which this VLAN gets

created.

Example: ::

  ethernets:

    eno1: {...}

  vlans:

    en-intra:

      id: 1

      link: eno1

      dhcp4: yes

    en-vpn:

      id: 2

      link: eno1

      address: ...

Examples

--------

Configure an ethernet device with networkd, identified by its name, and enable

DHCP: ::

  network:

    version: 2

    ethernets:

      eno1:

        dhcp4: true

This is a complex example which shows most available features: ::

  network:

    version: 2

    ethernets:

      # opaque ID for physical interfaces, only referred to by other stanzas

      id0:

        match:

          macaddress: 00:11:22:33:44:55

        wakeonlan: true

        dhcp4: true

        addresses:

          - 192.168.14.2/24

          - 2001:1::1/64

        gateway4: 192.168.14.1

        gateway6: 2001:1::2

        nameservers:

          search: [foo.local, bar.local]

          addresses: [8.8.8.8]

      lom:

        match:

          driver: ixgbe

        # you are responsible for setting tight enough match rules

        # that only match one device if you use set-name

        set-name: lom1

        dhcp6: true

      switchports:

        # all cards on second PCI bus; unconfigured by themselves, will be added

        # to br0 below

        match:

          name: enp2*

        mtu: 1280

    bonds:

      bond0:

        interfaces: [id0, lom]

    bridges:

      # the key name is the name for virtual (created) interfaces; no match: and

      # set-name: allowed

      br0:

        # IDs of the components; switchports expands into multiple interfaces

        interfaces: [wlp1s0, switchports]

        dhcp4: true

    vlans:

      en-intra:

        id: 1

        link: id0

        dhcp4: yes

    # static routes

    routes:

     - to: 0.0.0.0/0

       via: 11.0.0.1

       metric: 3

.. _netplan: https://launchpad.net/netplan

.. vi: textwidth=78