<?xml version='1.0'?>
-<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
-
-<!--
- SPDX-License-Identifier: LGPL-2.1+
--->
+<!-- SPDX-License-Identifier: LGPL-2.1+ -->
<refentry id="systemd.link">
<refentryinfo>
same name pointing to <filename>/dev/null</filename> disables the
configuration file entirely (it is "masked").</para>
- <para>The link file contains a <literal>[Match]</literal> section,
- which determines if a given link file may be applied to a given
- device, as well as a <literal>[Link]</literal> section specifying
- how the device should be configured. The first (in lexical order)
- of the link files that matches a given device is applied. Note
- that a default file <filename>99-default.link</filename> is
- shipped by the system. Any user-supplied
- <filename>.link</filename> should hence have a lexically earlier
- name to be considered at all.</para>
-
- <para>See
- <citerefentry><refentrytitle>udevadm</refentrytitle><manvolnum>8</manvolnum></citerefentry>
- for diagnosing problems with <filename>.link</filename> files.</para>
+ <para>The link file contains a [Match] section, which determines if a given link file may be applied to a
+ given device, as well as a [Link] section specifying how the device should be configured. The first (in
+ lexical order) of the link files that matches a given device is applied. Note that a default file
+ <filename>99-default.link</filename> is shipped by the system. Any user-supplied
+ <filename>.link</filename> should hence have a lexically earlier name to be considered at all.</para>
+
+ <para>See <citerefentry><refentrytitle>udevadm</refentrytitle><manvolnum>8</manvolnum></citerefentry> for
+ diagnosing problems with <filename>.link</filename> files.</para>
</refsect1>
<refsect1>
<title>[Match] Section Options</title>
- <para>A link 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>
+ <para>A link file is said to match a device if all matches specified by the
+ <literal>[Match]</literal> section are satisfied. When a link file does not contain valid settings
+ in <literal>[Match]</literal> section, then the file will match all devices and
+ <command>systemd-udevd</command> warns about that. Hint: to avoid the warning and to make it clear
+ that all interfaces shall be matched, add the following:
+ <programlisting>OriginalName=*</programlisting>
+ The following keys are accepted:</para>
<variablelist class='network-directives'>
<varlistentry>
<listitem>
<para>A whitespace-separated list of shell-style globs matching
the persistent path, as exposed by the udev property
- <literal>ID_PATH</literal>.</para>
+ <varname>ID_PATH</varname>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>Driver=</varname></term>
<listitem>
- <para>A whitespace-separated list of shell-style globs matching
- 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>
+ <para>A whitespace-separated list of shell-style globs matching the driver currently bound to the
+ device, as exposed by the udev property <varname>DRIVER</varname> of its parent device, or if that
+ is not set, the driver as exposed by <command>ethtool -i</command> of the device itself.</para>
</listitem>
</varlistentry>
<varlistentry>
<listitem>
<para>A whitespace-separated list of shell-style globs matching
the device type, as exposed by the udev
- property <literal>DEVTYPE</literal>.</para>
+ property <varname>DEVTYPE</varname>.</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
+ <para>Matches against the hostname or machine ID of the host. See <varname>ConditionHost=</varname> in
<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
- for details.</para>
+ for details. When prefixed with an exclamation mark (<literal>!</literal>), the result is negated.
+ If an empty string is assigned, then previously assigned value is cleared.
+ </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
+ <para>Checks whether the system is executed in a virtualized environment and optionally test
+ whether it is a specific implementation. See <varname>ConditionVirtualization=</varname> in
<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
- for details.</para>
+ for details. When prefixed with an exclamation mark (<literal>!</literal>), the result is negated.
+ If an empty string is assigned, then previously assigned value is cleared.
+ </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
+ <para>Checks whether a specific kernel command line option is set. See
+ <varname>ConditionKernelCommandLine=</varname> in
<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
- for details.</para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><varname>KernelVersion=</varname></term>
- <listitem>
- <para>Checks whether the kernel version (as reported by <command>uname -r</command>) matches a certain
- expression (or if prefixed with the exclamation mark does not match it). See
- <literal>ConditionKernelVersion=</literal> in
- <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
- details.
- </para>
- </listitem>
- </varlistentry>
+ for details. When prefixed with an exclamation mark (<literal>!</literal>), the result is negated.
+ If an empty string is assigned, then previously assigned value is cleared.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>KernelVersion=</varname></term>
+ <listitem>
+ <para>Checks whether the kernel version (as reported by <command>uname -r</command>) matches a certain
+ expression. See <varname>ConditionKernelVersion=</varname> in
+ <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
+ details. When prefixed with an exclamation mark (<literal>!</literal>), the result is negated.
+ If an empty string is assigned, then previously assigned value is cleared.
+ </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
+ <para>Checks whether the system is running on a specific architecture. See
+ <varname>ConditionArchitecture=</varname> in
<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
- for details.</para>
+ for details. When prefixed with an exclamation mark (<literal>!</literal>), the result is negated.
+ If an empty string is assigned, then previously assigned value is cleared.
+ </para>
</listitem>
</varlistentry>
</variablelist>
<refsect1>
<title>[Link] Section Options</title>
- <para>The <literal>[Link]</literal> section accepts the following
+ <para>The [Link] section accepts the following
keys:</para>
<variablelist class='network-directives'>
<varlistentry>
<term><varname>Alias=</varname></term>
<listitem>
- <para>The <literal>ifalias</literal> is set to this
- value.</para>
+ <para>The <varname>ifalias</varname> interface property is set to this value.</para>
</listitem>
</varlistentry>
<varlistentry>
<variablelist>
<varlistentry>
- <term><literal>persistent</literal></term>
+ <term><option>persistent</option></term>
<listitem>
<para>If the hardware has a persistent MAC address, as
most hardware should, and if it is used by the kernel,
</listitem>
</varlistentry>
<varlistentry>
- <term><literal>random</literal></term>
+ <term><option>random</option></term>
<listitem>
<para>If the kernel is using a random MAC address,
nothing is done. Otherwise, a new address is randomly
</listitem>
</varlistentry>
<varlistentry>
- <term><literal>none</literal></term>
+ <term><option>none</option></term>
<listitem>
<para>Keeps the MAC address assigned by the kernel.</para>
</listitem>
<term><varname>MACAddress=</varname></term>
<listitem>
<para>The MAC address to use, if no
- <literal>MACAddressPolicy=</literal>
+ <varname>MACAddressPolicy=</varname>
is specified.</para>
</listitem>
</varlistentry>
<term><varname>NamePolicy=</varname></term>
<listitem>
<para>An ordered, space-separated list of policies by which the interface name should be set.
- <literal>NamePolicy</literal> may be disabled by specifying <literal>net.ifnames=0</literal> on the
- kernel command line. Each of the policies may fail, and the first successful one is used. The name
- is not set directly, but is exported to udev as the property <literal>ID_NET_NAME</literal>, which
- is, by default, used by a udev rule to set <literal>NAME</literal>. The available policies are:
+ <varname>NamePolicy=</varname> may be disabled by specifying <option>net.ifnames=0</option> on the
+ kernel command line. Each of the policies may fail, and the first successful one is used. The name
+ is not set directly, but is exported to udev as the property <option>ID_NET_NAME</option>, which
+ is, by default, used by a
+ <citerefentry><refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
+ rule to set <varname>NAME</varname>. The available policies are:
</para>
<variablelist>
<varlistentry>
- <term><literal>kernel</literal></term>
+ <term><option>kernel</option></term>
<listitem>
<para>If the kernel claims that the name it has set
for a device is predictable, then no renaming is
</listitem>
</varlistentry>
<varlistentry>
- <term><literal>database</literal></term>
+ <term><option>database</option></term>
<listitem>
<para>The name is set based on entries in the udev's
Hardware Database with the key
- <literal>ID_NET_NAME_FROM_DATABASE</literal>.
+ <varname>ID_NET_NAME_FROM_DATABASE</varname>.
</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><literal>onboard</literal></term>
+ <term><option>onboard</option></term>
<listitem>
<para>The name is set based on information given by
the firmware for on-board devices, as exported by the
- udev property <literal>ID_NET_NAME_ONBOARD</literal>.
+ udev property <varname>ID_NET_NAME_ONBOARD</varname>.
+ See <citerefentry><refentrytitle>systemd.net-naming-scheme</refentrytitle><manvolnum>7</manvolnum></citerefentry>.
</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><literal>slot</literal></term>
+ <term><option>slot</option></term>
<listitem>
<para>The name is set based on information given by
the firmware for hot-plug devices, as exported by the
- udev property <literal>ID_NET_NAME_SLOT</literal>.
+ udev property <varname>ID_NET_NAME_SLOT</varname>.
+ See <citerefentry><refentrytitle>systemd.net-naming-scheme</refentrytitle><manvolnum>7</manvolnum></citerefentry>.
</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><literal>path</literal></term>
+ <term><option>path</option></term>
<listitem>
<para>The name is set based on the device's physical
location, as exported by the udev property
- <literal>ID_NET_NAME_PATH</literal>.</para>
+ <varname>ID_NET_NAME_PATH</varname>.
+ See <citerefentry><refentrytitle>systemd.net-naming-scheme</refentrytitle><manvolnum>7</manvolnum></citerefentry>.
+ </para>
</listitem>
</varlistentry>
<varlistentry>
- <term><literal>mac</literal></term>
+ <term><option>mac</option></term>
<listitem>
<para>The name is set based on the device's persistent
MAC address, as exported by the udev property
- <literal>ID_NET_NAME_MAC</literal>.</para>
+ <varname>ID_NET_NAME_MAC</varname>.
+ See <citerefentry><refentrytitle>systemd.net-naming-scheme</refentrytitle><manvolnum>7</manvolnum></citerefentry>.
+ </para>
</listitem>
</varlistentry>
<varlistentry>
- <term><literal>keep</literal></term>
+ <term><option>keep</option></term>
<listitem>
<para>If the device already had a name given by userspace (as part of creation of the device
or a rename), keep it.</para>
<varlistentry>
<term><varname>Name=</varname></term>
<listitem>
- <para>The interface name to use in case all the
- policies specified in
- <varname>NamePolicy=</varname> fail, or in case
- <varname>NamePolicy=</varname> is missing or
- disabled.</para>
+ <para>The interface name to use. This option has lower precedence than
+ <varname>NamePolicy=</varname>, so for this setting to take effect, <varname>NamePolicy=</varname>
+ must either be unset, empty, disabled, or all policies configured there must fail. Also see the
+ example below with <literal>Name=dmz0</literal>.</para>
<para>Note that specifying a name that the kernel might use for another
interface (for example <literal>eth0</literal>) is dangerous because the
<varlistentry>
<term><varname>Duplex=</varname></term>
<listitem>
- <para>The duplex mode to set for the device. The accepted
- values are <literal>half</literal> and
- <literal>full</literal>.</para>
+ <para>The duplex mode to set for the device. The accepted values are <option>half</option> and
+ <option>full</option>.</para>
</listitem>
</varlistentry>
<varlistentry>
common transmission parameters, such as speed, duplex mode, and flow control.
When unset, the kernel's default will be used.</para>
- <para>Note that if autonegotiation is enabled, speed, duplex and advertise settings are
- read-only. If autonegotation is disabled, speed, duplex and advertise settings are writable
+ <para>Note that if autonegotiation is enabled, speed and duplex settings are
+ read-only. If autonegotation is disabled, speed and duplex settings are writable
if the driver supports multiple link modes.</para>
</listitem>
</varlistentry>
<variablelist>
<varlistentry>
- <term><literal>phy</literal></term>
+ <term><option>phy</option></term>
<listitem>
<para>Wake on PHY activity.</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><literal>unicast</literal></term>
+ <term><option>unicast</option></term>
<listitem>
<para>Wake on unicast messages.</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><literal>multicast</literal></term>
+ <term><option>multicast</option></term>
<listitem>
<para>Wake on multicast messages.</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><literal>broadcast</literal></term>
+ <term><option>broadcast</option></term>
<listitem>
<para>Wake on broadcast messages.</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><literal>arp</literal></term>
+ <term><option>arp</option></term>
<listitem>
<para>Wake on ARP.</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><literal>magic</literal></term>
+ <term><option>magic</option></term>
<listitem>
<para>Wake on receipt of a magic packet.
</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><literal>secureon</literal></term>
+ <term><option>secureon</option></term>
<listitem>
<para>Enable secureon(tm) password for MagicPacket(tm).
</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><literal>off</literal></term>
+ <term><option>off</option></term>
<listitem>
<para>Never wake.</para>
</listitem>
</varlistentry>
</variablelist>
- <para>Defaults to <literal>off</literal>.</para>
+ <para>Defaults to <option>off</option>.</para>
</listitem>
</varlistentry>
<varlistentry>
<variablelist>
<varlistentry>
- <term><literal>tp</literal></term>
+ <term><option>tp</option></term>
<listitem>
<para>An Ethernet interface using Twisted-Pair cable as the medium.</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><literal>aui</literal></term>
+ <term><option>aui</option></term>
<listitem>
<para>Attachment Unit Interface (AUI). Normally used with hubs.
</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><literal>bnc</literal></term>
+ <term><option>bnc</option></term>
<listitem>
<para>An Ethernet interface using BNC connectors and co-axial cable.</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><literal>mii</literal></term>
+ <term><option>mii</option></term>
<listitem>
<para>An Ethernet interface using a Media Independent Interface (MII).</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><literal>fibre</literal></term>
+ <term><option>fibre</option></term>
<listitem>
<para>An Ethernet interface using Optical Fibre as the medium.</para>
</listitem>
<term><varname>Advertise=</varname></term>
<listitem>
<para>This sets what speeds and duplex modes of operation are advertised for auto-negotiation.
- The supported values are:
+ This implies <literal>AutoNegotiation=yes</literal>. The supported values are:
<table>
<title>Supported advertise values</title>
<entry>Duplex Mode</entry>
</row></thead>
<tbody>
-
- <row><entry><literal>10baset-half</literal></entry>
+ <row><entry><option>10baset-half</option></entry>
<entry>10</entry><entry>half</entry></row>
- <row><entry><literal>10baset-full</literal></entry>
+ <row><entry><option>10baset-full</option></entry>
<entry>10</entry><entry>full</entry></row>
- <row><entry><literal>100baset-half</literal></entry>
+ <row><entry><option>100baset-half</option></entry>
<entry>100</entry><entry>half</entry></row>
- <row><entry><literal>100baset-full</literal></entry>
+ <row><entry><option>100baset-full</option></entry>
<entry>100</entry><entry>full</entry></row>
- <row><entry><literal>1000baset-half</literal></entry>
+ <row><entry><option>1000baset-half</option></entry>
<entry>1000</entry><entry>half</entry></row>
- <row><entry><literal>1000baset-full</literal></entry>
+ <row><entry><option>1000baset-full</option></entry>
<entry>1000</entry><entry>full</entry></row>
- <row><entry><literal>10000baset-full</literal></entry>
+ <row><entry><option>10000baset-full</option></entry>
<entry>10000</entry><entry>full</entry></row>
- <row><entry><literal>2500basex-full</literal></entry>
+ <row><entry><option>2500basex-full</option></entry>
<entry>2500</entry><entry>full</entry></row>
- <row><entry><literal>1000basekx-full</literal></entry>
+ <row><entry><option>1000basekx-full</option></entry>
<entry>1000</entry><entry>full</entry></row>
- <row><entry><literal>10000basekx4-full</literal></entry>
+ <row><entry><option>10000basekx4-full</option></entry>
<entry>10000</entry><entry>full</entry></row>
- <row><entry><literal>10000basekr-full</literal></entry>
+ <row><entry><option>10000basekr-full</option></entry>
<entry>10000</entry><entry>full</entry></row>
- <row><entry><literal>10000baser-fec</literal></entry>
+ <row><entry><option>10000baser-fec</option></entry>
<entry>10000</entry><entry>full</entry></row>
- <row><entry><literal>20000basemld2-full</literal></entry>
+ <row><entry><option>20000basemld2-full</option></entry>
<entry>20000</entry><entry>full</entry></row>
- <row><entry><literal>20000basekr2-full</literal></entry>
+ <row><entry><option>20000basekr2-full</option></entry>
<entry>20000</entry><entry>full</entry></row>
</tbody>
</tgroup>
<example>
<title>/etc/systemd/network/10-dmz.link</title>
- <para>This example assigns the fixed name
- <literal>dmz0</literal> to the interface with the MAC address
+ <para>This example assigns the fixed name <literal>dmz0</literal> to the interface with the MAC address
00:a0:de:63:7a:e6:</para>
<programlisting>[Match]
[Link]
Name=dmz0</programlisting>
+
+ <para><varname>NamePolicy=</varname> is not set, so <varname>Name=</varname> takes effect. We use the
+ <literal>10-</literal> prefix to order this file early in the list. Note that it needs to before
+ <literal>99-link</literal>, i.e. it needs a numerical prefix, to have any effect at all.</para>
+ </example>
+
+ <example>
+ <title>Debugging <varname>NamePolicy=</varname> assignments</title>
+
+ <programlisting>$ sudo SYSTEMD_LOG_LEVEL=debug udevadm test-builtin net_setup_link /sys/class/net/hub0
+…
+Parsed configuration file /usr/lib/systemd/network/99-default.link
+Parsed configuration file /etc/systemd/network/10-eth0.link
+ID_NET_DRIVER=cdc_ether
+Config file /etc/systemd/network/10-eth0.link applies to device hub0
+link_config: autonegotiation is unset or enabled, the speed and duplex are not writable.
+hub0: Device has name_assign_type=4
+Using default interface naming scheme 'v240'.
+hub0: Policies didn't yield a name, using specified Name=hub0.
+ID_NET_LINK_FILE=/etc/systemd/network/10-eth0.link
+ID_NET_NAME=hub0
+…</programlisting>
+
+ <para>Explicit <varname>Name=</varname> configuration wins in this case.</para>
+
+ <programlisting>sudo SYSTEMD_LOG_LEVEL=debug udevadm test-builtin net_setup_link /sys/class/net/enp0s31f6
+…
+Parsed configuration file /usr/lib/systemd/network/99-default.link
+Parsed configuration file /etc/systemd/network/10-eth0.link
+Created link configuration context.
+ID_NET_DRIVER=e1000e
+Config file /usr/lib/systemd/network/99-default.link applies to device enp0s31f6
+link_config: autonegotiation is unset or enabled, the speed and duplex are not writable.
+enp0s31f6: Device has name_assign_type=4
+Using default interface naming scheme 'v240'.
+enp0s31f6: Policy *keep*: keeping existing userspace name
+enp0s31f6: Device has addr_assign_type=0
+enp0s31f6: MAC on the device already matches policy *persistent*
+ID_NET_LINK_FILE=/usr/lib/systemd/network/99-default.link
+…
+</programlisting>
+
+ <para>In this case, the interface was already renamed, so the <option>keep</option> policy specified as
+ the first option in <filename noindex='true'>99-default.link</filename> means that the existing name is
+ preserved. If <option>keep</option> was removed, or if were in boot before the renaming has happened,
+ we might get the following instead:</para>
+
+ <programlisting>enp0s31f6: Policy *path* yields "enp0s31f6".
+enp0s31f6: Device has addr_assign_type=0
+enp0s31f6: MAC on the device already matches policy *persistent*
+ID_NET_LINK_FILE=/usr/lib/systemd/network/99-default.link
+ID_NET_NAME=enp0s31f6
+…
+</programlisting>
+
+ <para>Please note that the details of output are subject to change.</para>
</example>
<example>
projects / thirdparty / systemd.git / blobdiff