<para><command>systemd-networkd</command> is a system
service that manages networks. It detects and configures
- network devices as they appear.</para>
+ network devices as they appear, as well as creating virtual
+ network devices.</para>
+
+ <para>To configure low-level link settings independently of
+ networks, see
+ <citerefentry><refentrytitle>systemd.link</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
<para>Network configurations applied before networkd is started
- are not removed, and configuration applied by networkd are not
- removed when networkd exits. This ensures restarting networkd
- does not cut the network connection, and in particular that it
- is safe to transition between the initrd and the real root,
+ are not removed, and static configuration applied by networkd
+ is not removed when networkd exits. Dynamic configuration applied by
+ networkd may also optionally be left in place on shutdown. This ensures
+ restarting networkd does not cut the network connection, and, in particular,
+ that it is safe to transition between the initrd and the real root,
and back.</para>
</refsect1>
- <refsect1><title>Network Configuration</title>
- <para>The network files are read from the files located in the
+ <refsect1><title>Configuration Files</title>
+ <para>The configuration 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 link 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 network file with a local file if needed; a symlink in
- <filename>/etc</filename> with the same name as a network file in
- <filename>/lib</filename>, pointing to <filename>/dev/null</filename>,
- disables the network file entirely. Network files must have the extension
- <filename>.network</filename>; other extensions are ignored.</para>
-
- <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>.</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>.
- </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>.</para>
- </listitem>
- </varlistentry>
- </variablelist>
-
- <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>Address</varname></term>
- <listitem>
- <para>A static IPv4 or IPv6 address and its prefix length,
- separated by a '/' character. The format of the address must
- be as described in
- <citerefentry><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>
- .</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>
- .</para>
- </listitem>
- </varlistentry>
- </variablelist>
+ network directory <filename>/etc/systemd/network</filename>.</para>
+
+ <para>Networks are configured in <filename>.network</filename> files, see
+ <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ and virtual network devices are configured in <filename>.netdev</filename> files, see
+ <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
+ </para>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.link</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd-network-wait-online.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
</para>
</refsect1>
~ianmdlvl / elogind.git / blobdiff