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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"

"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">

<refentry id="systemd.netdev" conditional='ENABLE_NETWORKD'>

<refentryinfo>

<title>systemd.network</title>

<productname>systemd</productname>

<authorgroup>

<author>

<contrib>Developer</contrib>

<firstname>Tom</firstname>

<surname>Gundersen</surname>

<email>teg@jklm.no</email>

</author>

</authorgroup>

</refentryinfo>

<refmeta>

<refentrytitle>systemd.netdev</refentrytitle>

<manvolnum>5</manvolnum>

</refmeta>

<refnamediv>

<refname>systemd.netdev</refname>

<refpurpose>Virtual Network Device configuration</refpurpose>

</refnamediv>

<refsynopsisdiv>

<para><filename><replaceable>netdev</replaceable>.netdev</filename></para>

</refsynopsisdiv>

<refsect1>

<title>Description</title>

<para>Network setup is performed by

<citerefentry><refentrytitle>systemd-networkd</refentrytitle><manvolnum>8</manvolnum></citerefentry>.

</para>

<para>Virtual Network Device files must have the extension

<filename>.netdev</filename>; other extensions are ignored. Virtual

network devices are created as soon as networkd is started.</para>

<para>The <filename>.netdev</filename> files are read from the files located in the

system network directory <filename>/usr/lib/systemd/network</filename>,

the volatile runtime network directory

<filename>/run/systemd/network</filename> and the local administration

network directory <filename>/etc/systemd/network</filename>.

All configuration files are collectively sorted and processed in lexical order,

regardless of the directories in which they live. However, files with

identical filenames replace each other. Files in

<filename>/etc</filename> have the highest priority, files in

<filename>/run</filename> take precedence over files with the same

name in <filename>/usr/lib</filename>. This can be used to override a

system-supplied configuration file with a local file if needed; a symlink in

<filename>/etc</filename> with the same name as a configuration file in

<filename>/usr/lib</filename>, pointing to <filename>/dev/null</filename>,

disables the configuration file entirely.</para>

</refsect1>

<refsect1>

<title>[Match] Section Options</title>

<para>A virtual network device is only created if the

<literal>[Match]</literal> section matches the current

environment, or if the section is empty. The following keys are accepted:</para>

<variablelist class='network-directives'>

<varlistentry>

<term><varname>Host=</varname></term>

<listitem>

<para>Matches against the hostname or machine ID of the

host. See <literal>ConditionHost=</literal> in

<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>

for details.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>Virtualization=</varname></term>

<listitem>

<para>Checks whether the system is executed in a virtualized

environment and optionally test whether it is a specific

implementation. See <literal>ConditionVirtualization=</literal> in

<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>

for details.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>KernelCommandLine=</varname></term>

<listitem>

<para>Checks whether a specific kernel command line option is

set (or if prefixed with the exclamation mark unset). See

<literal>ConditionKernelCommandLine=</literal> in

<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>

for details.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>Architecture=</varname></term>

<listitem>

<para>Checks whether the system is running on a specific

architecture. See <literal>ConditionArchitecture=</literal> in

<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>

for details.

</para>

</listitem>

</varlistentry>

</variablelist>

</refsect1>

<refsect1>

<title>[NetDev] Section Options</title>

<para>The <literal>[NetDev]</literal> section accepts the following

keys:</para>

<variablelist class='network-directives'>

<varlistentry>

<term><varname>Description=</varname></term>

<listitem>

<para>A free-form description of the netdev.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>Name=</varname></term>

<listitem>

<para>The interface name used when creating the

netdev. This option is compulsory.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>Kind=</varname></term>

<listitem>

<para>The netdev kind. Currently, <literal>bridge</literal>,

<literal>bond</literal>, <literal>vlan</literal>,

<literal>macvlan</literal>, <literal>vxlan</literal>,

<literal>ipip</literal>, <literal>gre</literal>,

<literal>sit</literal>, <literal>vti</literal>,

<literal>veth</literal>, and <literal>dummy</literal>

are supported. This option is compulsory.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>MTUBytes=</varname></term>

<listitem>

<para>The maximum transmission unit in bytes to

set for the device. The usual suffixes K, M, G,

are supported and are understood to the base of

1024.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>MACAddress=</varname></term>

<listitem>

<para>The MAC address to use for the device.

If none is given, one is generated based on

the interface name and the

<citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>.

</para>

</listitem>

</varlistentry>

</variablelist>

</refsect1>

<refsect1>

<title>[VLAN] Section Options</title>

<para>The <literal>[VLAN]</literal> section only applies for netdevs of kind <literal>vlan</literal>,

and accepts the following key:</para>

<variablelist class='network-directives'>

<varlistentry>

<term><varname>Id=</varname></term>

<listitem>

<para>The VLAN ID to use. An integer in the range 0–4094.

This option is compulsory.</para>

</listitem>

</varlistentry>

</variablelist>

</refsect1>

<refsect1>

<title>[MACVLAN] Section Options</title>

<para>The <literal>[MACVLAN]</literal> section only applies for netdevs of kind

<literal>macvlan</literal>, and accepts the following key:</para>

<variablelist class='network-directives'>

<varlistentry>

<term><varname>Mode=</varname></term>

<listitem>

<para>The MACVLAN mode to use. The supported options are

<literal>private</literal>, <literal>vepa</literal>,

<literal>bridge</literal> and <literal>passthru</literal>.

</para>

</listitem>

</varlistentry>

</variablelist>

</refsect1>

<refsect1>

<title>[VXLAN] Section Options</title>

<para>The <literal>[VXLAN]</literal> section only applies for netdevs of kind

<literal>vxlan</literal>, and accepts the following key:</para>

<variablelist class='network-directives'>

<varlistentry>

<term><varname>Id=</varname></term>

<listitem>

<para>The VXLAN ID to use.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>Group=</varname></term>

<listitem>

<para>An assigned multicast group IP address.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>TOS=</varname></term>

<listitem>

<para>The Type Of Service byte value for a vxlan interface.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>TTL=</varname></term>

<listitem>

<para>A fixed Time To Live N on Virtual eXtensible Local Area Network packets.

N is a number in the range 1-255. 0 is a special value meaning that packets

inherit the TTL value.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>MacLearning=</varname></term>

<listitem>

<para>A boolean. When true, enables dynamic MAC learning

to discover remote MAC addresses.</para>

</listitem>

</varlistentry>

</variablelist>

</refsect1>

<refsect1>

<title>[Tunnel] Section Options</title>

<para>The <literal>[Tunnel]</literal> section only applies for netdevs of kind

<literal>ipip</literal>, <literal>sit</literal>, <literal>gre</literal> and

<literal>vti</literal> and accepts the following keys:</para>

<variablelist class='network-directives'>

<varlistentry>

<term><varname>Local=</varname></term>

<listitem>

<para>A static local address for tunneled packets.

It must be an address on another interface of this host.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>Remote=</varname></term>

<listitem>

<para>The remote endpoint of the tunnel.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>TOS=</varname></term>

<listitem>

<para>The Type Of Service byte value for a tunnel interface.

For details about the TOS see the

<ulink url="http://tools.ietf.org/html/rfc1349">

Type of Service in the Internet Protocol Suite

</ulink> document.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>TTL=</varname></term>

<listitem>

<para>A fixed Time To Live N on tunneled packets.

N is a number in the range 1-255. 0 is a special value meaning that packets

inherit the TTL value. The default value for IPv4 tunnels is: inherit.

The default value for IPv6 tunnels is: 64.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>DiscoverPathMTU=</varname></term>

<listitem>

<para>A boolean. When true, enables Path MTU Discovery on the tunnel.</para>

</listitem>

</varlistentry>

</variablelist>

</refsect1>

<refsect1>

<title>[Peer] Section Options</title>

<para>The <literal>[Peer]</literal> section only applies for netdevs of kind <literal>veth</literal>

and accepts the following key:</para>

<variablelist class='network-directives'>

<varlistentry>

<term><varname>Name=</varname></term>

<listitem>

<para>The interface name used when creating the netdev.

This option is compulsory.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>MACAddress=</varname></term>

<listitem>

<para>The peer MACAddress, if not set it is generated in the same

way as the MAC address of the main interface.</para>

</listitem>

</varlistentry>

</variablelist>

</refsect1>

<refsect1>

<title>[TUN] Section Options</title>

<para>The <literal>[TUN]</literal> section only applies for netdevs of kind

<literal>tun</literal>, and accepts the following keys:</para>

<variablelist class='network-directives'>

<varlistentry>

<term><varname>OneQueue=</varname></term>

<listitem><para>Takes a boolean argument. Configures whether

to enable disable one queue . it determines whether all packets

queue at the device (enabled), or a fixed number queue at the device and

the rest at the "qdisc". Defaults to <literal>no</literal>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>MultiQueue=</varname></term>

<listitem><para>Takes a boolean argument. Configures whether the

to disable or disable . Linux supports multiqueue tuntap which can

uses multiple file descriptors (queues) to parallelize

packets sending or receiving. The device allocation is the same as before,

and if user wants to create multiple queues. Defaults to

<literal>no</literal>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>PacketInfo=</varname></term>

<listitem><para>Takes a boolean argument. Configures whether the

to enable or disable . PacketInfo tells the kernel to not provide packet

information. The purpose of PacketInfo is to tell the kernel that packets

will be "pure" IP packets, with no added bytes. Otherwise (if PacketInfo is unset),

4 extra bytes are added to the beginning of the packet (2 flag bytes and 2 protocol bytes).

Defaults to <literal>no</literal>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>User=</varname></term>

<listitem><para>User to be allowed to access this device. Give ownership to unprivileged users,

so that /dev/net/tun device to be usable by this user.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>Group=</varname></term>

<listitem><para>Group to be allowed to access this device. Give ownership to unprivileged group,

so that /dev/net/tun device to be usable by this group.</para>

</listitem>

</varlistentry>

</variablelist>

</refsect1>

<refsect1>

<title>[TAP] Section Options</title>

<para>The <literal>[TAP]</literal> section only applies for netdevs of kind

<literal>tap</literal>, and accepts the following keys:</para>

</refsect1>

<variablelist class='network-directives'>

<varlistentry>

<term><varname>OneQueue=</varname></term>

<listitem><para>Takes a boolean argument. Configures whether

to enable disable one queue . it determines whether all packets

queue at the device (enabled), or a fixed number queue at the device and

the rest at the "qdisc". Defaults to <literal>no</literal>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>MultiQueue=</varname></term>

<listitem><para>Takes a boolean argument. Configures whether the

to disable or disable . From version 3.8, Linux supports multiqueue

tuntap which can uses multiple file descriptors (queues) to parallelize

packets sending or receiving. The device allocation is the same as before,

and if user wants to create multiple queues. Defaults to

<literal>no</literal>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>PacketInfo=</varname></term>

<listitem><para>Takes a boolean argument. Configures whether the

to enable or disable . PacketInfo tells the kernel to not provide packet

information. The purpose of PacketInfo is to tell the kernel that packets

will be "pure" IP packets, with no added bytes. Otherwise (if PacketInfo is unset),

4 extra bytes are added to the beginning of the packet (2 flag bytes and 2 protocol bytes).

Defaults to <literal>no</literal>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>User=</varname></term>

<listitem><para>User to be allowed to access this device. Give ownership to unprivileged users,

so that /dev/net/tun device to be usable by this user.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>Group=</varname></term>

<listitem><para>Group to be allowed to access this device. Give ownership to unprivileged group,

so that /dev/net/tun device to be usable by this group.</para>

</listitem>

</varlistentry>

</variablelist>

<refsect1>

<title>Example</title>

<example>

<title>/etc/systemd/network/bridge.netdev</title>

<programlisting>[NetDev]

Name=bridge0

Kind=bridge</programlisting>

</example>

<example>

<title>/etc/systemd/network/vlan1.netdev</title>

<programlisting>[Match]

Virtualization=no

[NetDev]

Name=vlan1

Kind=vlan

[VLAN]

Id=1</programlisting>

</example>

<example>

<title>/etc/systemd/network/ipip.netdev</title>

<programlisting>[NetDev]

Name=ipip-tun

Kind=ipip

MTUBytes=1480

[Tunnel]

Local=192.168.223.238

Remote=192.169.224.239

TTL=64</programlisting>

</example>

<example>

<title>/etc/systemd/network/tap.netdev</title>

<programlisting>[NetDev]

Name=tap-test

Kind=tap

[Tap]

MultiQueue=true

PacketInfo=true</programlisting> </example>

<example>

<title>/etc/systemd/network/sit.netdev</title>

<programlisting>[NetDev]

Name=sit-tun

Kind=sit

MTUBytes=1480

[Tunnel]

Local=10.65.223.238

Remote=10.65.223.239</programlisting>

</example>

<example>

<title>/etc/systemd/network/gre.netdev</title>

<programlisting>[NetDev]

Name=gre-tun

Kind=gre

MTUBytes=1480

[Tunnel]

Local=10.65.223.238

Remote=10.65.223.239</programlisting>

</example>

<example>

<title>/etc/systemd/network/vti.netdev</title>

<programlisting>[NetDev]

Name=vti-tun

Kind=vti

MTUBytes=1480

[Tunnel]

Local=10.65.223.238

Remote=10.65.223.239</programlisting>

</example>

<example>

<title>/etc/systemd/network/veth.netdev</title>

<programlisting>[NetDev]

Name=veth-test

Kind=veth

[Peer]

Name=veth-peer</programlisting>

</example>

<example>

<title>/etc/systemd/network/dummy.netdev</title>

<programlisting>[NetDev]

Name=dummy-test

Kind=dummy

MACAddress=12:34:56:78:9a:bc</programlisting>

</example>

</refsect1>

<refsect1>

<title>See Also</title>

<para>

<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,

<citerefentry><refentrytitle>systemd-networkd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,

<citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>

</para>

</refsect1>

</refentry>