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| <!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+ --> |
| |
| <refentry id="systemd.link"> |
| <refentryinfo> |
| <title>systemd.link</title> |
| <productname>systemd</productname> |
| </refentryinfo> |
| |
| <refmeta> |
| <refentrytitle>systemd.link</refentrytitle> |
| <manvolnum>5</manvolnum> |
| </refmeta> |
| |
| <refnamediv> |
| <refname>systemd.link</refname> |
| <refpurpose>Network device configuration</refpurpose> |
| </refnamediv> |
| |
| <refsynopsisdiv> |
| <para><filename><replaceable>link</replaceable>.link</filename></para> |
| </refsynopsisdiv> |
| |
| <refsect1> |
| <title>Description</title> |
| |
| <para>Network link configuration is performed by the |
| <command>net_setup_link</command> udev builtin.</para> |
| |
| <para>The link 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>. Link files must have |
| the extension <filename>.link</filename>; other extensions are |
| ignored. 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>/usr/lib</filename>. This can be used to |
| override a system-supplied link file with a local file if needed. |
| As a special case, an empty file (file size 0) or symlink with the |
| same name pointing to <filename>/dev/null</filename> disables the |
| configuration file entirely (it is "masked").</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 [Match] 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>A whitespace-separated list of hardware addresses. Use full colon-, hyphen- or dot-delimited hexadecimal. See the example below. |
| This option may appear more than once, in which case the lists are merged. If the empty string is assigned to this option, the list |
| of hardware addresses defined prior to this is reset.</para> |
| |
| <para>Example: |
| <programlisting>MACAddress=01:23:45:67:89:ab 00-11-22-33-44-55 AABB.CCDD.EEFF</programlisting></para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>OriginalName=</varname></term> |
| <listitem> |
| <para>A whitespace-separated list of shell-style globs matching |
| the device name, as exposed by the udev property |
| "INTERFACE". This cannot be used to match on names that have |
| already been changed from userspace. Caution is advised when matching on |
| kernel-assigned names, as they are known to be unstable |
| between reboots.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>Path=</varname></term> |
| <listitem> |
| <para>A whitespace-separated list of shell-style globs matching |
| the persistent path, as exposed by the udev property |
| <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 <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> |
| <term><varname>Type=</varname></term> |
| <listitem> |
| <para>A whitespace-separated list of shell-style globs matching |
| the device type, as exposed by the udev |
| 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 <varname>ConditionHost=</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>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 <varname>ConditionVirtualization=</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>KernelCommandLine=</varname></term> |
| <listitem> |
| <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. 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 |
| <varname>ConditionArchitecture=</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> |
| </variablelist> |
| |
| </refsect1> |
| |
| <refsect1> |
| <title>[Link] Section Options</title> |
| |
| <para>The [Link] section accepts the following |
| keys:</para> |
| |
| <variablelist class='network-directives'> |
| <varlistentry> |
| <term><varname>Description=</varname></term> |
| <listitem> |
| <para>A description of the device.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>Alias=</varname></term> |
| <listitem> |
| <para>The <varname>ifalias</varname> interface property is set to this value.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>MACAddressPolicy=</varname></term> |
| <listitem> |
| <para>The policy by which the MAC address should be set. The |
| available policies are: |
| </para> |
| |
| <variablelist> |
| <varlistentry> |
| <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, |
| nothing is done. Otherwise, a new MAC address is |
| generated which is guaranteed to be the same on every |
| boot for the given machine and the given device, but |
| which is otherwise random. This feature depends on ID_NET_NAME_* |
| properties to exist for the link. On hardware where these |
| properties are not set, the generation of a persistent MAC address |
| will fail.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <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 |
| generated each time the device appears, typically at |
| boot. Either way, the random address will have the |
| <literal>unicast</literal> and |
| <literal>locally administered</literal> bits set.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>none</option></term> |
| <listitem> |
| <para>Keeps the MAC address assigned by the kernel.</para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>MACAddress=</varname></term> |
| <listitem> |
| <para>The MAC address to use, if no |
| <varname>MACAddressPolicy=</varname> |
| is specified.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>NamePolicy=</varname></term> |
| <listitem> |
| <para>An ordered, space-separated list of policies by which the interface name should be set. |
| <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><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 |
| performed.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>database</option></term> |
| <listitem> |
| <para>The name is set based on entries in the udev's |
| Hardware Database with the key |
| <varname>ID_NET_NAME_FROM_DATABASE</varname>. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <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 <varname>ID_NET_NAME_ONBOARD</varname>. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <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 <varname>ID_NET_NAME_SLOT</varname>. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>path</option></term> |
| <listitem> |
| <para>The name is set based on the device's physical |
| location, as exported by the udev property |
| <varname>ID_NET_NAME_PATH</varname>.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <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 |
| <varname>ID_NET_NAME_MAC</varname>.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <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> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>Name=</varname></term> |
| <listitem> |
| <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 |
| name assignment done by udev will race with the assignment done by the |
| kernel, and only one interface may use the name. Depending on the order of |
| operations, either udev or the kernel will win, making the naming |
| unpredictable. It is best to use some different prefix, for example |
| <literal>internal0</literal>/<literal>external0</literal> or |
| <literal>lan0</literal>/<literal>lan1</literal>/<literal>lan3</literal>. |
| </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>BitsPerSecond=</varname></term> |
| <listitem> |
| <para>The speed to set for the device, the value is rounded |
| down to the nearest Mbps. The usual suffixes K, M, G, are |
| supported and are understood to the base of 1000.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>Duplex=</varname></term> |
| <listitem> |
| <para>The duplex mode to set for the device. The accepted values are <option>half</option> and |
| <option>full</option>.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>AutoNegotiation=</varname></term> |
| <listitem> |
| <para>Takes a boolean. If set to yes, automatic negotiation of transmission parameters is enabled. |
| Autonegotiation is a procedure by which two connected ethernet devices choose |
| 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 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> |
| <varlistentry> |
| <term><varname>WakeOnLan=</varname></term> |
| <listitem> |
| <para>The Wake-on-LAN policy to set for the device. The |
| supported values are:</para> |
| |
| <variablelist> |
| <varlistentry> |
| <term><option>phy</option></term> |
| <listitem> |
| <para>Wake on PHY activity.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>unicast</option></term> |
| <listitem> |
| <para>Wake on unicast messages.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>multicast</option></term> |
| <listitem> |
| <para>Wake on multicast messages.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>broadcast</option></term> |
| <listitem> |
| <para>Wake on broadcast messages.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>arp</option></term> |
| <listitem> |
| <para>Wake on ARP.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>magic</option></term> |
| <listitem> |
| <para>Wake on receipt of a magic packet. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>secureon</option></term> |
| <listitem> |
| <para>Enable secureon(tm) password for MagicPacket(tm). |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>off</option></term> |
| <listitem> |
| <para>Never wake.</para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| |
| <para>Defaults to <option>off</option>.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>Port=</varname></term> |
| <listitem> |
| <para>The port option is used to select the device port. The |
| supported values are:</para> |
| |
| <variablelist> |
| <varlistentry> |
| <term><option>tp</option></term> |
| <listitem> |
| <para>An Ethernet interface using Twisted-Pair cable as the medium.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>aui</option></term> |
| <listitem> |
| <para>Attachment Unit Interface (AUI). Normally used with hubs. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>bnc</option></term> |
| <listitem> |
| <para>An Ethernet interface using BNC connectors and co-axial cable.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>mii</option></term> |
| <listitem> |
| <para>An Ethernet interface using a Media Independent Interface (MII).</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>fibre</option></term> |
| <listitem> |
| <para>An Ethernet interface using Optical Fibre as the medium.</para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>Advertise=</varname></term> |
| <listitem> |
| <para>This sets what speeds and duplex modes of operation are advertised for auto-negotiation. |
| This implies <literal>AutoNegotiation=yes</literal>. The supported values are: |
| |
| <table> |
| <title>Supported advertise values</title> |
| <tgroup cols='3'> |
| <colspec colname='Advertise' /> |
| <colspec colname='Speed' /> |
| <colspec colname='Duplex Mode' /> |
| |
| <thead><row> |
| <entry>Advertise</entry> |
| <entry>Speed (Mbps)</entry> |
| <entry>Duplex Mode</entry> |
| </row></thead> |
| <tbody> |
| <row><entry><option>10baset-half</option></entry> |
| <entry>10</entry><entry>half</entry></row> |
| |
| <row><entry><option>10baset-full</option></entry> |
| <entry>10</entry><entry>full</entry></row> |
| |
| <row><entry><option>100baset-half</option></entry> |
| <entry>100</entry><entry>half</entry></row> |
| |
| <row><entry><option>100baset-full</option></entry> |
| <entry>100</entry><entry>full</entry></row> |
| |
| <row><entry><option>1000baset-half</option></entry> |
| <entry>1000</entry><entry>half</entry></row> |
| |
| <row><entry><option>1000baset-full</option></entry> |
| <entry>1000</entry><entry>full</entry></row> |
| |
| <row><entry><option>10000baset-full</option></entry> |
| <entry>10000</entry><entry>full</entry></row> |
| |
| <row><entry><option>2500basex-full</option></entry> |
| <entry>2500</entry><entry>full</entry></row> |
| |
| <row><entry><option>1000basekx-full</option></entry> |
| <entry>1000</entry><entry>full</entry></row> |
| |
| <row><entry><option>10000basekx4-full</option></entry> |
| <entry>10000</entry><entry>full</entry></row> |
| |
| <row><entry><option>10000basekr-full</option></entry> |
| <entry>10000</entry><entry>full</entry></row> |
| |
| <row><entry><option>10000baser-fec</option></entry> |
| <entry>10000</entry><entry>full</entry></row> |
| |
| <row><entry><option>20000basemld2-full</option></entry> |
| <entry>20000</entry><entry>full</entry></row> |
| |
| <row><entry><option>20000basekr2-full</option></entry> |
| <entry>20000</entry><entry>full</entry></row> |
| </tbody> |
| </tgroup> |
| </table> |
| |
| By default this is unset, i.e. all possible modes will be advertised. |
| This option may be specified more than once, in which case all specified speeds and modes are advertised. |
| If the empty string is assigned to this option, the list is reset, and all prior assignments have no effect. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>TCPSegmentationOffload=</varname></term> |
| <listitem> |
| <para>Takes a boolean. If set to true, the TCP Segmentation Offload (TSO) is enabled. |
| When unset, the kernel's default will be used.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>TCP6SegmentationOffload=</varname></term> |
| <listitem> |
| <para>Takes a boolean. If set to true, the TCP6 Segmentation Offload (tx-tcp6-segmentation) is enabled. |
| When unset, the kernel's default will be used.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>GenericSegmentationOffload=</varname></term> |
| <listitem> |
| <para>Takes a boolean. If set to true, the Generic Segmentation Offload (GSO) is enabled. |
| When unset, the kernel's default will be used.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>GenericReceiveOffload=</varname></term> |
| <listitem> |
| <para>Takes a boolean. If set to true, the Generic Receive Offload (GRO) is enabled. |
| When unset, the kernel's default will be used.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>LargeReceiveOffload=</varname></term> |
| <listitem> |
| <para>Takes a boolean. If set to true, the Large Receive Offload (LRO) is enabled. |
| When unset, the kernel's default will be used.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>RxChannels=</varname></term> |
| <listitem> |
| <para>Sets the number of receive channels (a number between 1 and 4294967295) .</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>TxChannels=</varname></term> |
| <listitem> |
| <para>Sets the number of transmit channels (a number between 1 and 4294967295).</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>OtherChannels=</varname></term> |
| <listitem> |
| <para>Sets the number of other channels (a number between 1 and 4294967295).</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>CombinedChannels=</varname></term> |
| <listitem> |
| <para>Sets the number of combined set channels (a number between 1 and 4294967295).</para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </refsect1> |
| |
| <refsect1> |
| <title>Examples</title> |
| |
| <example> |
| <title>/usr/lib/systemd/network/99-default.link</title> |
| |
| <para>The link file <filename>99-default.link</filename> that is |
| shipped with systemd defines the default naming policy for |
| links.</para> |
| |
| <programlisting>[Link] |
| NamePolicy=kernel database onboard slot path |
| MACAddressPolicy=persistent</programlisting> |
| </example> |
| |
| <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 |
| 00:a0:de:63:7a:e6:</para> |
| |
| <programlisting>[Match] |
| MACAddress=00:a0:de:63:7a:e6 |
| |
| [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> |
| <title>/etc/systemd/network/10-internet.link</title> |
| |
| <para>This example assigns the fixed name |
| <literal>internet0</literal> to the interface with the device |
| path <literal>pci-0000:00:1a.0-*</literal>:</para> |
| |
| <programlisting>[Match] |
| Path=pci-0000:00:1a.0-* |
| |
| [Link] |
| Name=internet0</programlisting> |
| </example> |
| |
| <example> |
| <title>/etc/systemd/network/25-wireless.link</title> |
| |
| <para>Here's an overly complex example that shows the use of a large number of [Match] and [Link] settings.</para> |
| |
| <programlisting>[Match] |
| MACAddress=12:34:56:78:9a:bc |
| Driver=brcmsmac |
| Path=pci-0000:02:00.0-* |
| Type=wlan |
| Virtualization=no |
| Host=my-laptop |
| Architecture=x86-64 |
| |
| [Link] |
| Name=wireless0 |
| MTUBytes=1450 |
| BitsPerSecond=10M |
| WakeOnLan=magic |
| MACAddress=cb:a9:87:65:43:21</programlisting> |
| </example> |
| </refsect1> |
| |
| <refsect1> |
| <title>See Also</title> |
| <para> |
| <citerefentry> |
| <refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum> |
| </citerefentry>, |
| <citerefentry> |
| <refentrytitle>udevadm</refentrytitle><manvolnum>8</manvolnum> |
| </citerefentry>, |
| <citerefentry> |
| <refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum> |
| </citerefentry>, |
| <citerefentry> |
| <refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum> |
| </citerefentry> |
| </para> |
| </refsect1> |
| |
| </refentry> |