-<?xml version='1.0'?> <!--*-nxml-*-->
+<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!--
+ SPDX-License-Identifier: LGPL-2.1+
+
This file is part of systemd.
Copyright 2014 Tom Gundersen
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
+ 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>
<listitem>
<para>A whitespace-separated list of shell-style globs matching
the device name, as exposed by the udev property
- "INTERFACE". This can not be used to match on names that have
+ "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>
<varname>NamePolicy=</varname> fail, or in case
<varname>NamePolicy=</varname> is missing or
disabled.</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>
<literal>full</literal>.</para>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><varname>AutoNegotiation=</varname></term>
+ <listitem>
+ <para>Enables or disables automatic negotiation of transmission parameters.
+ Autonegotiation is a procedure by which two connected ethernet devices choose
+ common transmission parameters, such as speed, duplex mode, and flow control.
+ Takes a boolean value. Unset by default, which means that the kernel 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>Wake on PHY activity.</para>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><literal>unicast</literal></term>
+ <listitem>
+ <para>Wake on unicast messages.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><literal>multicast</literal></term>
+ <listitem>
+ <para>Wake on multicast messages.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><literal>broadcast</literal></term>
+ <listitem>
+ <para>Wake on broadcast messages.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><literal>arp</literal></term>
+ <listitem>
+ <para>Wake on ARP.</para>
+ </listitem>
+ </varlistentry>
<varlistentry>
<term><literal>magic</literal></term>
<listitem>
</para>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><literal>secureon</literal></term>
+ <listitem>
+ <para>Enable secureon(tm) password for MagicPacket(tm).
+ </para>
+ </listitem>
+ </varlistentry>
<varlistentry>
<term><literal>off</literal></term>
<listitem>
</variablelist>
</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><literal>tp</literal></term>
+ <listitem>
+ <para>An Ethernet interface using Twisted-Pair cable as the medium.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><literal>aui</literal></term>
+ <listitem>
+ <para>Attachment Unit Interface (AUI). Normally used with hubs.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><literal>bnc</literal></term>
+ <listitem>
+ <para>An Ethernet interface using BNC connectors and co-axial cable.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><literal>mii</literal></term>
+ <listitem>
+ <para>An Ethernet interface using a Media Independent Interface (MII).</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><literal>fibre</literal></term>
+ <listitem>
+ <para>An Ethernet interface using Optical Fibre as the medium.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>TCPSegmentationOffload=</varname></term>
+ <listitem>
+ <para>The TCP Segmentation Offload (TSO) when true enables
+ TCP segmentation offload. Takes a boolean value.
+ Defaults to "unset".</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>TCP6SegmentationOffload=</varname></term>
+ <listitem>
+ <para>The TCP6 Segmentation Offload (tx-tcp6-segmentation) when true enables
+ TCP6 segmentation offload. Takes a boolean value.
+ Defaults to "unset".</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>GenericSegmentationOffload=</varname></term>
+ <listitem>
+ <para>The Generic Segmentation Offload (GSO) when true enables
+ generic segmentation offload. Takes a boolean value.
+ Defaults to "unset".</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>UDPSegmentationOffload=</varname></term>
+ <listitem>
+ <para>The UDP Segmentation Offload (USO) when true enables
+ UDP segmentation offload. Takes a boolean value.
+ Defaults to "unset".</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>GenericReceiveOffload=</varname></term>
+ <listitem>
+ <para>The Generic Receive Offload (GRO) when true enables
+ generic receive offload. Takes a boolean value.
+ Defaults to "unset".</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>LargeReceiveOffload=</varname></term>
+ <listitem>
+ <para>The Large Receive Offload (LRO) when true enables
+ large receive offload. Takes a boolean value.
+ Defaults to "unset".</para>
+ </listitem>
+ </varlistentry>
</variablelist>
</refsect1>
<refsect1>
- <title>Example</title>
+ <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>
+ </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