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<?xml version='1.0'?> <!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!--
This file is part of systemd.
Copyright 2013 Tom Gundersen
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
-->
<refentry id="systemd.network" 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.network</refentrytitle>
<manvolnum>5</manvolnum>
</refmeta>
<refnamediv>
<refname>systemd.network</refname>
<refpurpose>Network configuration</refpurpose>
</refnamediv>
<refsynopsisdiv>
<para><filename><replaceable>network</replaceable>.network</filename></para>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>Network setup is performed by
<citerefentry><refentrytitle>systemd-networkd</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
</para>
<para>Network files must have the extension <filename>.network</filename>;
other extensions are ignored. Networks are applied to links whenever the links
appear.</para>
<para>The <filename>.network</filename> files are read from the files located in the
system network directory <filename>/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>/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>/lib</filename>, pointing to <filename>/dev/null</filename>,
disables the configuration file entirely.</para>
</refsect1>
<refsect1>
<title>[Match] Section Options</title>
<para>The network file contains a <literal>[Match]</literal> section,
which determines if a given network file may be applied to a given device;
and a <literal>[Network]</literal> section specifying how the device should
be configured. The first (in lexical order) of the network files that
matches a given device is applied.</para>
<para>A network file is said to match a device if each of the entries in the
<literal>[Match]</literal> section matches, or if the section is empty.
The following keys are accepted:</para>
<variablelist class='network-directives'>
<varlistentry>
<term><varname>MACAddress=</varname></term>
<listitem>
<para>The hardware address.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>Path=</varname></term>
<listitem>
<para>The persistent path, as exposed by the udev
property <literal>ID_PATH</literal>. May contain shell
style globs.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>Driver=</varname></term>
<listitem>
<para>The driver currently bound to the device, as
exposed by the udev property <literal>DRIVER</literal>
of its parent device, or if that is not set the driver
as exposed by <literal>ethtool -i</literal> of the
device itself.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>Type=</varname></term>
<listitem>
<para>The device type, as exposed by the udev property
<literal>DEVTYPE</literal>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>Name=</varname></term>
<listitem>
<para>The device name, as exposed by the udev property
<literal>INTERFACE</literal>. May contain shell style
globs.</para>
</listitem>
</varlistentry>
<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>[Network] Section Options</title>
<para>The <literal>[Network]</literal> section accepts the following keys:</para>
<variablelist class='network-directives'>
<varlistentry>
<term><varname>Description=</varname></term>
<listitem>
<para>A description of the device. This is only used for
presentation purposes.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>DHCP=</varname></term>
<listitem>
<para>Enables DHCPv4 and/or DHCPv6 support. Accepts
<literal>both</literal>, <literal>none</literal>,
<literal>v4</literal> or <literal>v6</literal>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>DHCPServer=</varname></term>
<listitem>
<para>A boolean. Enables a basic DHCPv4 server on the
device. Mostly useful for handing out leases to container
instances.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>IPv4LL=</varname></term>
<listitem>
<para>A boolean. When true, enables IPv4 link-local support.
If <literal>DHCP=</literal> is also true, acquiring DHCP address
will deprecate previously acquired IPv4 link-local address or
stop acquiring process if one has not been acquired before.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>Address=</varname></term>
<listitem>
<para>A static IPv4 or IPv6 address and its prefix length,
separated by a <literal>/</literal> character. Specify this
key more than once to configure several addresses.
The format of the address must be as described in
<citerefentry><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
This is a short-hand for an [Address] section only containing
an Address key (see below). This option may be specified
more than once.
</para>
<para>If the specified
address is 0.0.0.0
(for IPv4) or [::]
(for IPv6), a new
address range of the
requested size is
automatically
allocated from a
system-wide pool of
unused ranges. The
allocated range is
checked against all
current network
interfaces and all
known network
configuration files to
avoid address range
conflicts. The default
system-wide pool
consists of
192.168.0.0/16,
172.16.0.0/12 and
10.0.0.0/8 for IPv4,
and fc00::/7 for
IPv6. This
functionality is
useful to manage a
large number of
dynamically created
network interfaces
with the same network
configuration and
automatic address
range
assignment.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>Gateway=</varname></term>
<listitem>
<para>The gateway address, which must be in the format described in
<citerefentry><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
This is a short-hand for a [Route] section only containing a Gateway
key. This option may be specified more than once.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>DNS=</varname></term>
<listitem>
<para>A DNS server address, which must be in the format described in
<citerefentry><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
This option may be specified more than once.</para>
</listitem>
</varlistentry>
<!-- TODO: document NTP= option when it is actually used somewhere -->
<varlistentry>
<term><varname>Bridge=</varname></term>
<listitem>
<para>The name of the bridge to add the link to.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>Bond=</varname></term>
<listitem>
<para>The name of the bond to add the link to.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>VLAN=</varname></term>
<listitem>
<para>The name of a VLAN to create on the link. This option
may be specified more than once.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>MACVLAN=</varname></term>
<listitem>
<para>The name of a MACVLAN to create on the link. This option
may be specified more than once.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>VXLAN=</varname></term>
<listitem>
<para>The name of a VXLAN to create on the link. This option
may be specified more than once.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>Tunnel=</varname></term>
<listitem>
<para>The name of a Tunnel to create on the link. This option
may be specified more than once.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>[Address] Section Options</title>
<para>An <literal>[Address]</literal> section accepts the following keys.
Specify several <literal>[Address]</literal> sections to configure several
addresses.</para>
<variablelist class='network-directives'>
<varlistentry>
<term><varname>Address=</varname></term>
<listitem>
<para>As in the <literal>[Network]</literal> section. This key is mandatory.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>Broadcast=</varname></term>
<listitem>
<para>The broadcast address, which must be in the format described in
<citerefentry><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
This key only applies to IPv4 addresses. If it is not given, it is
derived from the <literal>Address</literal> key.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>Label=</varname></term>
<listitem>
<para>An address label.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>[Route] Section Options</title>
<para>The <literal>[Route]</literal> section accepts the following keys. Specify
several <literal>[Route]</literal> sections to configure several routes.</para>
<variablelist class='network-directives'>
<varlistentry>
<term><varname>Gateway=</varname></term>
<listitem>
<para>As in the <literal>[Network]</literal> section. This key is mandatory.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>Destination=</varname></term>
<listitem>
<para>The destination prefix of the route. Possibly followed by a slash and the
prefixlength. If ommitted, a full-length host route is assumed.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>[DHCP] Section Options</title>
<para>The <literal>[DHCP]</literal> section accepts the following keys:</para>
<variablelist class='network-directives'>
<varlistentry>
<term><varname>UseDNS=</varname></term>
<listitem>
<para>When true (the default), the DNS servers received from the DHCP server will
be used and take precedence over any statically configured ones.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>UseMTU=</varname></term>
<listitem>
<para>When true, the interface maximum transmission unit from the DHCP server will
be used on the current link. Defaults to false.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>SendHostname=</varname></term>
<listitem>
<para>When true (the default), the machine's hostname will be sent to the DHCP
server</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>UseHostname=</varname></term>
<listitem>
<para>When true (the default), the hostname received from the DHCP server
will be used as the transient hostname.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>UseRoutes=</varname></term>
<listitem>
<para>When true (the default), the static routes will be requested from the DHCP server
and added to the routing table with metric of 1024.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>CriticalConnection=</varname></term>
<listitem>
<para>When true, the connection will never be torn down even if the DHCP lease
expires. This is contrary to the DHCP specification, but may be the best choice
if, say, the root filesystem relies on this connection. Defaults to false.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Example</title>
<example>
<title>/etc/systemd/network/50-static.network</title>
<programlisting>[Match]
Name=enp2s0
[Network]
Address=192.168.0.15/24
Gateway=192.168.0.1</programlisting>
</example>
<example>
<title>/etc/systemd/network/80-dhcp.network</title>
<programlisting>[Match]
Name=en*
[Network]
DHCP=yes</programlisting>
</example>
<example>
<title>/etc/systemd/network/bridge-static.network</title>
<programlisting>[Match]
Name=bridge0
[Network]
Address=192.168.0.15/24
Gateway=192.168.0.1
DNS=192.168.0.1</programlisting>
</example>
<example>
<title>/etc/systemd/network/bridge-slave-interface.network</title>
<programlisting>[Match]
Name=enp2s0
[Network]
Bridge=bridge0</programlisting>
</example>
<example>
<title>/etc/systemd/network/ipip.network</title>
<programlisting>[Match]
Name=em1
[Network]
Tunnel=ipip-tun</programlisting>
</example>
<example>
<title>/etc/systemd/network/sit.network</title>
<programlisting>[Match]
Name=em1
[Network]
Tunnel=sit-tun</programlisting>
</example>
<example>
<title>/etc/systemd/network/gre.network</title>
<programlisting>[Match]
Name=em1
[Network]
Tunnel=gre-tun</programlisting>
</example>
<example>
<title>/etc/systemd/network/vti.network</title>
<programlisting>[Match]
Name=em1
[Network]
Tunnel=vti-tun</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.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>
|
