man/networkd.conf.xml - main - niceSOFT/systemd

man/networkd.conf.xml
489 строк23 KB
Yu Watanabe
man: document DHCP relay configuration
21 май 2026, 10:55
21 май 2026, 10:55aa063e5
<?xml version='1.0'?>
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
  "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">

<!--
  SPDX-License-Identifier: LGPL-2.1-or-later

  Copyright © 2014 Vinay Kulkarni
-->

<refentry id="networkd.conf" conditional='ENABLE_NETWORKD'
    xmlns:xi="http://www.w3.org/2001/XInclude">
  <refentryinfo>
    <title>networkd.conf</title>
    <productname>systemd</productname>
  </refentryinfo>

  <refmeta>
    <refentrytitle>networkd.conf</refentrytitle>
    <manvolnum>5</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>networkd.conf</refname>
    <refname>networkd.conf.d</refname>
    <refpurpose>Global Network configuration files</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <para><simplelist>
      <member><filename>/etc/systemd/networkd.conf</filename></member>
      <member><filename>/run/systemd/networkd.conf</filename></member>
      <member><filename>/usr/local/lib/systemd/networkd.conf</filename></member>
      <member><filename>/usr/lib/systemd/networkd.conf</filename></member>
      <member><filename>/etc/systemd/networkd.conf.d/*.conf</filename></member>
      <member><filename>/run/systemd/networkd.conf.d/*.conf</filename></member>
      <member><filename>/usr/local/lib/systemd/networkd.conf.d/*.conf</filename></member>
      <member><filename>/usr/lib/systemd/networkd.conf.d/*.conf</filename></member>
    </simplelist></para>
  </refsynopsisdiv>

  <refsect1>
    <title>Description</title>

    <para>These configuration files control global network parameters.</para>
  </refsect1>

  <xi:include href="standard-conf.xml" xpointer="main-conf" />

  <refsect1>
    <title>[Network] Section Options</title>

    <para>The following options are available in the [Network] section:</para>

    <variablelist class='network-directives'>
      <varlistentry>
        <term><varname>SpeedMeter=</varname></term>
        <listitem><para>Takes a boolean. If set to yes, then <command>systemd-networkd</command>
        measures the traffic of each interface, and
        <command>networkctl status <replaceable>INTERFACE</replaceable></command> shows the measured speed.
        Defaults to no.</para>

        <xi:include href="version-info.xml" xpointer="v244"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>SpeedMeterIntervalSec=</varname></term>
        <listitem><para>Specifies the time interval to calculate the traffic speed of each interface.
        If <varname>SpeedMeter=no</varname>, the value is ignored. Defaults to 10sec.</para>

        <xi:include href="version-info.xml" xpointer="v244"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>ManageForeignRoutingPolicyRules=</varname></term>
        <listitem><para>A boolean. When true, <command>systemd-networkd</command> will remove rules
        that are not configured in .network files (except for rules with protocol
        <literal>kernel</literal>). When false, it will not remove any foreign rules, keeping them even
        if they are not configured in a .network file. Defaults to yes.
        </para>

        <xi:include href="version-info.xml" xpointer="v249"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>ManageForeignRoutes=</varname></term>
        <listitem><para>A boolean. When true, <command>systemd-networkd</command> will remove routes
        that are not configured in .network files (except for routes with protocol
        <literal>kernel</literal>, <literal>dhcp</literal> when <varname>KeepConfiguration=</varname>
        is true or <literal>dhcp</literal>, and <literal>static</literal> when
        <varname>KeepConfiguration=</varname> is true or <literal>static</literal>). When false, it will
        not remove any foreign routes, keeping them even if they are not configured in a .network file.
        Defaults to yes.</para>

        <xi:include href="version-info.xml" xpointer="v246"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>ManageForeignNextHops=</varname></term>
        <listitem><para>A boolean. When true, <command>systemd-networkd</command> will remove nexthops
        that are not configured in .network files (except for routes with protocol
        <literal>kernel</literal>). When false, it will
        not remove any foreign nexthops, keeping them even if they are not configured in a .network file.
        Defaults to yes.</para>

        <xi:include href="version-info.xml" xpointer="v256"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>RouteTable=</varname></term>
        <listitem><para>Defines the route table name. Takes a whitespace-separated list of the pairs of
        route table name and number. The route table name and number in each pair are separated with a
        colon, i.e., <literal><replaceable>name</replaceable>:<replaceable>number</replaceable></literal>.
        The route table name must not be <literal>default</literal>, <literal>main</literal>, or
        <literal>local</literal>, as these route table names are predefined with route table number 253,
        254, and 255, respectively. The route table number must be an integer in the range 1…4294967295,
        except for predefined numbers 253, 254, and 255. This setting can be specified multiple times.
        If an empty string is specified, then the list specified earlier are cleared. Defaults to unset.
        </para>

        <xi:include href="version-info.xml" xpointer="v248"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>IPv4Forwarding=</varname></term>
        <listitem>
          <para>Configures IPv4 packet forwarding for the system. Takes a boolean value. This controls the
          <filename>net.ipv4.conf.default.forwarding</filename> and
          <filename>net.ipv4.conf.all.forwarding</filename> sysctl options. See
          <ulink url="https://docs.kernel.org/networking/ip-sysctl.html">IP Sysctl</ulink>
          for more details about the sysctl options. Defaults to unset and the sysctl options will not be
          changed.</para>

          <para>If an interface is configured with a .network file that enables <varname>IPMasquerade=</varname>
          for IPv4 (that is, <literal>ipv4</literal> or <literal>both</literal>), this setting is implied
          unless explicitly specified. See <varname>IPMasquerade=</varname> in
          <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>
          for more details.</para>

          <xi:include href="version-info.xml" xpointer="v256"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>IPv6Forwarding=</varname></term>
        <listitem>
          <para>Configures IPv6 packet forwarding for the system. Takes a boolean value. This controls the
          <filename>net.ipv6.conf.default.forwarding</filename> and
          <filename>net.ipv6.conf.all.forwarding</filename> sysctl options. See
          <ulink url="https://docs.kernel.org/networking/ip-sysctl.html">IP Sysctl</ulink>
          for more details about the sysctl options. Defaults to unset and the sysctl options will not be
          changed.</para>

          <para>If an interface is configured with a .network file that enables <varname>IPMasquerade=</varname>
          for IPv6 (that is, <literal>ipv6</literal> or <literal>both</literal>), this setting is implied
          unless explicitly specified. See <varname>IPMasquerade=</varname> in
          <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>
          for more details.</para>

          <xi:include href="version-info.xml" xpointer="v256"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>IPv6PrivacyExtensions=</varname></term>
        <listitem>
          <para>Specifies the default value for per-network <varname>IPv6PrivacyExtensions=</varname>.
          Takes a boolean or the special values <literal>prefer-public</literal> and
          <literal>kernel</literal>. See for details in
          <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
          Defaults to <literal>no</literal>.</para>

        <xi:include href="version-info.xml" xpointer="v254"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>UseDomains=</varname></term>
        <listitem>
          <para>Specifies the network- and protocol-independent default value for the same settings in
          [IPv6AcceptRA], [DHCPv4], and [DHCPv6] sections below. Takes a boolean, or the special value
          <option>route</option>. See the same setting in
          <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
          Defaults to <literal>no</literal>.</para>

          <xi:include href="version-info.xml" xpointer="v256"/>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>[IPv6AcceptRA] Section Options</title>

    <para>This section configures the default setting of the Neighbor Discovery. The following options are
    available in the [IPv6AcceptRA] section:</para>

    <variablelist class='network-directives'>
      <varlistentry>
        <term><varname>UseDomains=</varname></term>
        <listitem>
          <para>Specifies the network-independent default value for the same setting in the [IPv6AcceptRA]
          section in
          <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
          Takes a boolean, or the special value <option>route</option>. When unspecified, the value specified
          in the [Network] section in
          <citerefentry><refentrytitle>networkd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
          which defaults to <literal>no</literal>, will be used.</para>

          <xi:include href="version-info.xml" xpointer="v256"/>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>[IPv6AddressLabel] Section Options</title>

    <para>An [IPv6AddressLabel] section accepts the following keys. Specify multiple [IPv6AddressLabel]
    sections to configure multiple address labels. IPv6 address labels are used for address selection.
    See <ulink url="https://tools.ietf.org/html/rfc3484">RFC 3484</ulink>. Precedence is managed by
    userspace, and only the label itself is stored in the kernel.</para>

    <variablelist class='network-directives'>
      <varlistentry>
        <term><varname>Label=</varname></term>
        <listitem>
          <para>The label for the prefix, an unsigned integer in the range 0…4294967294. 0xffffffff is
          reserved. This setting is mandatory.</para>

          <xi:include href="version-info.xml" xpointer="v257"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>Prefix=</varname></term>
        <listitem>
          <para>IPv6 prefix is an address with a prefix length, separated by a slash
          <literal>/</literal> character. This setting is mandatory.</para>

          <xi:include href="version-info.xml" xpointer="v257"/>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>[DHCPv4] Section Options</title>

    <para>This section configures the default configurations of DHCPv4 client. If the DHCPv4 client is
    enabled on an interface, then the configurations below will be used by default unless explicitly
    specified in the corresponding <filename>.network</filename> file. See also
    <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
    </para>

    <para>The following options are understood:</para>

    <variablelist class='network-directives'>
      <varlistentry>
        <term><varname>ClientIdentifier=</varname></term>
        <listitem>
          <para>Specifies the default DHCPv4 client identifier to be used. Takes one of <option>mac</option>
          or <option>duid</option>. If set to <option>mac</option>, the MAC address of each link will be used.
          If set to <option>duid</option>, an RFC4361-compliant Client ID, which is the combination of IAID
          and DUID, is used. IAID can be configured by <varname>IAID=</varname> in each matching
          <filename>.network</filename> file. DUID can be configured by <varname>DUIDType=</varname> and
          <varname>DUIDRawData=</varname>. Defaults to <option>duid</option>.</para>

        <xi:include href="version-info.xml" xpointer="v258"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>DUIDType=</varname></term>
        <listitem><para>Specifies how the DUID should be generated. See
        <ulink url="https://tools.ietf.org/html/rfc3315#section-9">RFC 3315</ulink>
        for a description of all the options.</para>

        <para>This takes an integer in the range 0…65535, or one of the following string values:
        <variablelist>
          <varlistentry>
            <term><option>vendor</option></term>
            <listitem><para>If <literal>DUIDType=vendor</literal>, then the DUID value will be generated using
            <literal>43793</literal> as the vendor identifier (systemd) and hashed contents of
            <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
            This is the default if <varname>DUIDType=</varname> is not specified.
            </para>

            <xi:include href="version-info.xml" xpointer="v230"/></listitem>
          </varlistentry>

          <varlistentry>
            <term><option>uuid</option></term>
            <listitem><para>If <literal>DUIDType=uuid</literal>, and <varname>DUIDRawData=</varname> is not set,
            then the product UUID is used as a DUID value. If a system does not have valid product UUID, then
            an application-specific
            <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>
            is used as a DUID value. About the application-specific machine ID, see
            <citerefentry><refentrytitle>sd_id128_get_machine_app_specific</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
            </para>

            <xi:include href="version-info.xml" xpointer="v230"/></listitem>
          </varlistentry>

          <varlistentry>
            <term><option>link-layer-time[:<replaceable>TIME</replaceable>]</option></term>
            <term><option>link-layer</option></term>
            <listitem><para>If <literal>link-layer-time</literal> or <literal>link-layer</literal> is specified,
            then the MAC address of the interface is used as a DUID value. The value <literal>link-layer-time</literal>
            can take additional time value after a colon, e.g. <literal>link-layer-time:2018-01-23 12:34:56 UTC</literal>.
            The default time value is <literal>2000-01-01 00:00:00 UTC</literal>.
            </para>

            <xi:include href="version-info.xml" xpointer="v240"/></listitem>
          </varlistentry>
        </variablelist>
        </para>

        <para>In all cases, <varname>DUIDRawData=</varname> can be used to override the
        actual DUID value that is used.</para>

        <xi:include href="version-info.xml" xpointer="v230"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>DUIDRawData=</varname></term>
        <listitem><para>Specifies the DHCP DUID value as a single newline-terminated, hexadecimal string, with each
        byte separated by <literal>:</literal>. The DUID that is sent is composed of the DUID type specified by
        <varname>DUIDType=</varname> and the value configured here.</para>

        <para>The DUID value specified here overrides the DUID that
        <citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
        generates from the machine ID. To configure DUID per-network, see
        <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
        The configured DHCP DUID should conform to the specification in
        <ulink url="http://tools.ietf.org/html/rfc3315#section-9">RFC 3315</ulink>,
        <ulink url="http://tools.ietf.org/html/rfc6355">RFC 6355</ulink>. To configure IAID, see
        <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum>
        </citerefentry>.</para>

        <example>
          <title>A <option>DUIDType=vendor</option> with a custom value</title>

          <programlisting>DUIDType=vendor
DUIDRawData=00:00:ab:11:f9:2a:c2:77:29:f9:5c:00</programlisting>

          <para>This specifies a 14 byte DUID, with the type DUID-EN (<literal>00:02</literal>), enterprise number
          43793 (<literal>00:00:ab:11</literal>), and identifier value <literal>f9:2a:c2:77:29:f9:5c:00</literal>.
          </para>
        </example>

          <xi:include href="version-info.xml" xpointer="v230"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>UseDomains=</varname></term>
        <listitem>
          <para>Same as the one in the [IPv6AcceptRA] section, but applied for DHCPv4 protocol.</para>

          <xi:include href="version-info.xml" xpointer="v256"/>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>[DHCPv6] Section Options</title>

    <para>This section configures the default configurations of DHCPv6 client. If the DHCPv6 client is
    enabled on an interface, then the configurations below will be used by default unless explicitly
    specified in the corresponding <filename>.network</filename> file. See also
    <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
    </para>

    <para>The following options are understood:</para>

    <variablelist class='network-directives'>
      <varlistentry>
        <term><varname>DUIDType=</varname></term>
        <term><varname>DUIDRawData=</varname></term>
        <listitem><para>As in the [DHCPv4] section.</para>

        <xi:include href="version-info.xml" xpointer="v249"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>UseDomains=</varname></term>
        <listitem><para>As in the [DHCPv4] section.</para>

        <xi:include href="version-info.xml" xpointer="v256"/></listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>[DHCPRelay] Section Options</title>
    <para>The [DHCPRelay] section contains host-wide settings for the DHCP relay agent.</para>

    <variablelist class='network-directives'>

      <varlistentry>
        <term><varname>ServerAddress=</varname></term>
        <listitem>
          <para>Specifies the IPv4 address of the upstream DHCP server. This is required for the host to act
          as a DHCP relay agent.</para>

          <xi:include href="version-info.xml" xpointer="v261"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>OverrideServerIdentifier=</varname></term>
        <listitem>
          <para>Takes a boolean value. When enabled, the Server Identifier Override sub-option and the Relay
          Agent Flags sub-option in the Relay Agent Information option will be appended to the DHCP message
          forwarded to the upstream DHCP server. Defaults to false.</para>

          <xi:include href="version-info.xml" xpointer="v261"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>RemoteId=</varname></term>
        <listitem>
          <para>Specifies the remote ID, which is typically used by DHCP servers to identify the DHCP relay
          agent. Takes a data type and data separated with a colon
          (<literal><replaceable>type</replaceable>:<replaceable>value</replaceable></literal>). The type
          takes one of <literal>uint8</literal>, <literal>uint16</literal>, <literal>uint32</literal>,
          <literal>ipv4address</literal>, <literal>ipv6address</literal>, or <literal>string</literal>.
          Special characters in the data string may be escaped using
          <ulink url="https://en.wikipedia.org/wiki/Escape_sequences_in_C#Table_of_escape_sequences">C-style escapes</ulink>.
          If unset, a UUID generated from the local machine ID will be used.</para>

          <xi:include href="version-info.xml" xpointer="v261"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>ExtraOption=</varname></term>
        <listitem>
          <para>Specifies an extra sub-option in the Relay Agent Information option, which is appended to
          DHCP messages forwarded to the upstream DHCP server. Takes a sub-option code, data type, and data
          separated with a colon
          (<literal><replaceable>code</replaceable>:<replaceable>type</replaceable>:<replaceable>value</replaceable></literal>).
          The code is an integer in 1…254. See <varname>RemoteId=</varname> in the above for the acceptable
          type and data. This setting can be specified multiple times. When an empty string is specified,
          all previous assignments are cleared. Defaults to unset, and no extra sub-option will be appended.
          </para>

          <xi:include href="version-info.xml" xpointer="v261"/>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>[DHCPServer] Section Options</title>

    <para>This section configures the default setting of the DHCP server. The following options are available
    in the [DHCPServer] section:</para>

    <variablelist class='network-directives'>
      <varlistentry>
        <term><varname>PersistLeases=</varname></term>
        <listitem>
          <para>Specifies the default value for per-network <varname>PersistLeases=</varname>.
          Takes a boolean or special value <literal>runtime</literal>. See for details in
          <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
          Defaults to <literal>yes</literal>.</para>

          <xi:include href="version-info.xml" xpointer="v256"/>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
      <title>See Also</title>
      <para><simplelist type="inline">
      <member><citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
      <member><citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
      <member><citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry></member>
      <member><citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
      <member><citerefentry><refentrytitle>sd_id128_get_machine_app_specific</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
      </simplelist></para>
  </refsect1>

</refentry>