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704 lines
36 KiB
XML
704 lines
36 KiB
XML
<?xml version='1.0'?>
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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
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"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
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<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
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<refentry id="systemd.net-naming-scheme" xmlns:xi="http://www.w3.org/2001/XInclude">
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<refentryinfo>
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<title>systemd.net-naming-scheme</title>
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<productname>systemd</productname>
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</refentryinfo>
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<refmeta>
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<refentrytitle>systemd.net-naming-scheme</refentrytitle>
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<manvolnum>7</manvolnum>
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</refmeta>
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<refnamediv>
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<refname>systemd.net-naming-scheme</refname>
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<refpurpose>Network device naming schemes</refpurpose>
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</refnamediv>
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<refsect1>
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<title>Description</title>
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<para>Network interfaces names and MAC addresses may be generated based on certain stable interface
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attributes. This is possible when there is enough information about the device to generate those
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attributes and the use of this information is configured. This page describes interface naming, i.e. what
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possible names may be generated. Those names are generated by the
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<citerefentry><refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
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builtin <command>net_id</command> and exported as udev properties
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(<varname>ID_NET_NAME_ONBOARD=</varname>, <varname>ID_NET_LABEL_ONBOARD=</varname>,
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<varname>ID_NET_NAME_PATH=</varname>, <varname>ID_NET_NAME_SLOT=</varname>).</para>
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<para>Names and MAC addresses are derived from various stable device metadata attributes. Newer versions
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of udev take more of these attributes into account, improving (and thus possibly changing) the names and
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addresses used for the same devices. Different versions of those generation rules are called "naming
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schemes". The default naming scheme is chosen at compilation time. Usually this will be the latest
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implemented version, but it is also possible to set one of the older versions to preserve
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compatibility. This may be useful for example for distributions, which may introduce new versions of
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systemd in stable releases without changing the naming scheme. The naming scheme may also be overridden
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using the <varname>net.naming_scheme=</varname> kernel command line switch, see
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<citerefentry><refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
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Available naming schemes are described below.</para>
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<para>After the udev properties have been generated, appropriate udev rules may be used to actually rename
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devices based on those properties. See the description of <varname>NamePolicy=</varname> and
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<varname>MACAddressPolicy=</varname> in
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<citerefentry><refentrytitle>systemd.link</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
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<para>Note that while the concept of network interface naming schemes is primarily relevant in the
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context of <filename>systemd-udevd.service</filename>, the
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<citerefentry><refentrytitle>systemd-nspawn</refentrytitle><manvolnum>1</manvolnum></citerefentry>
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container manager also takes it into account when naming network interfaces, see below.</para>
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</refsect1>
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<refsect1>
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<title>Policies</title>
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<para>All names start with a two-character prefix that signifies the interface type.</para>
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<table>
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<title>Two character prefixes based on the type of interface</title>
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<tgroup cols='2'>
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<thead>
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<row>
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<entry>Prefix</entry>
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<entry>Description</entry>
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</row>
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</thead>
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<tbody>
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<row>
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<entry><constant>en</constant></entry>
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<entry>Ethernet</entry>
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</row>
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<row>
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<entry><constant>ib</constant></entry>
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<entry>InfiniBand</entry>
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</row>
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<row>
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<entry><constant>sl</constant></entry>
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<entry>Serial line IP (slip)</entry>
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</row>
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<row>
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<entry><constant>wl</constant></entry>
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<entry>Wireless local area network (WLAN)</entry>
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</row>
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<row>
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<entry><constant>ww</constant></entry>
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<entry>Wireless wide area network (WWAN)</entry>
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</row>
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</tbody>
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</tgroup>
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</table>
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<para>The udev <command>net_id</command> builtin exports the following udev device properties:</para>
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<variablelist>
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<varlistentry>
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<term><varname>ID_NET_NAME_ONBOARD=</varname><replaceable>prefix</replaceable><constant>o</constant><replaceable>number</replaceable></term>
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<term><varname>ID_NET_NAME_ONBOARD=</varname><replaceable>prefix</replaceable><constant>d</constant><replaceable>number</replaceable></term>
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<listitem><para>This name is set based on the numeric ordering information given by the firmware
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for on-board devices. Different schemes are used depending on the firmware type, as described in
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the table below.</para>
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<table>
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<title>On-board naming schemes</title>
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<tgroup cols='2'>
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<thead>
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<row>
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<entry>Format</entry>
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<entry>Description</entry>
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</row>
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</thead>
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<tbody>
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<row>
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<entry><replaceable>prefix</replaceable><constant>o</constant><replaceable>number</replaceable></entry>
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<entry>PCI on-board index</entry>
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</row>
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<row>
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<entry><replaceable>prefix</replaceable><constant>d</constant><replaceable>number</replaceable></entry>
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<entry>Devicetree alias index</entry>
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</row>
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</tbody>
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</tgroup>
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</table>
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<xi:include href="version-info.xml" xpointer="v243"/>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>ID_NET_LABEL_ONBOARD=</varname><replaceable>prefix</replaceable> <replaceable>label</replaceable></term>
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<listitem><para>This property is set based on textual label given by the firmware for on-board
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devices. The name consists of the prefix concatenated with the label. This is only available for
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PCI devices.
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</para>
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<xi:include href="version-info.xml" xpointer="v243"/>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>ID_NET_NAME_MAC=</varname><replaceable>prefix</replaceable><constant>x</constant><replaceable>AABBCCDDEEFF</replaceable></term>
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<listitem><para>This name consists of the prefix, letter <constant>x</constant>, and 12 hexadecimal
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digits of the MAC address. It is available if the device has a fixed MAC address. Because this name
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is based on an attribute of the card itself, it remains "stable" when the device is moved (even
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between machines), but will change when the hardware is replaced.</para>
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<xi:include href="version-info.xml" xpointer="v243"/>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>ID_NET_NAME_SLOT=</varname><replaceable>prefix</replaceable>[<constant>P</constant><replaceable>domain</replaceable>]<constant>s</constant><replaceable>slot</replaceable>[<constant>f</constant><replaceable>function</replaceable>][<constant>n</constant><replaceable>port_name</replaceable>|<constant>d</constant><replaceable>dev_port</replaceable>]</term>
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<term><varname>ID_NET_NAME_SLOT=</varname><replaceable>prefix</replaceable><constant>v</constant><replaceable>slot</replaceable></term>
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<term><varname>ID_NET_NAME_SLOT=</varname><replaceable>prefix</replaceable><constant>x</constant><replaceable>slot</replaceable></term>
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<term><varname>ID_NET_NAME_SLOT=</varname><replaceable>prefix</replaceable>[<constant>P</constant><replaceable>domain</replaceable>]<constant>s</constant><replaceable>slot</replaceable>[<constant>f</constant><replaceable>function</replaceable>][<constant>n</constant><replaceable>port_name</replaceable>|<constant>d</constant><replaceable>dev_port</replaceable>]<constant>b</constant><replaceable>number</replaceable></term>
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<term><varname>ID_NET_NAME_SLOT=</varname><replaceable>prefix</replaceable>[<constant>P</constant><replaceable>domain</replaceable>]<constant>s</constant><replaceable>slot</replaceable>[<constant>f</constant><replaceable>function</replaceable>][<constant>n</constant><replaceable>port_name</replaceable>|<constant>d</constant><replaceable>dev_port</replaceable>]<constant>u</constant><replaceable>port</replaceable>…[<constant>c</constant><replaceable>config</replaceable>][<constant>i</constant><replaceable>interface</replaceable>]</term>
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<term><varname>ID_NET_NAME_SLOT=</varname><replaceable>prefix</replaceable>[<constant>P</constant><replaceable>domain</replaceable>]<constant>s</constant><replaceable>slot</replaceable>[<constant>f</constant><replaceable>function</replaceable>][<constant>n</constant><replaceable>port_name</replaceable>|<constant>d</constant><replaceable>dev_port</replaceable>]<constant>v</constant><replaceable>slot</replaceable></term>
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<term><varname>ID_NET_NAME_SLOT=</varname><replaceable>prefix</replaceable>[<constant>P</constant><replaceable>domain</replaceable>]<constant>s</constant><replaceable>slot</replaceable>[<constant>f</constant><replaceable>function</replaceable>][<constant>n</constant><replaceable>port_name</replaceable>|<constant>d</constant><replaceable>dev_port</replaceable>]<constant>r</constant><replaceable>slot</replaceable></term>
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<listitem><para>This property describes the slot position. Different schemes are used depending on
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the bus type, as described in the table below. In case of USB, BCMA, and SR-VIO devices, the full
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name consists of the prefix, PCI slot identifier, and USB or BCMA or SR-VIO slot identifier. The
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first two parts are denoted as "…" in the table below.</para>
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<table>
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<title>Slot naming schemes</title>
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<tgroup cols='2'>
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<thead>
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<row>
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<entry>Format</entry>
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<entry>Description</entry>
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</row>
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</thead>
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<tbody>
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<row>
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<entry><replaceable>prefix</replaceable> [<constant>P</constant><replaceable>domain</replaceable>] <constant>s</constant><replaceable>slot</replaceable> [<constant>f</constant><replaceable>function</replaceable>] [<constant>n</constant><replaceable>port_name</replaceable> | <constant>d</constant><replaceable>dev_port</replaceable>]</entry>
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<entry>PCI slot number</entry>
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</row>
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<row>
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<entry><replaceable>prefix</replaceable> <constant>v</constant><replaceable>slot</replaceable></entry>
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<entry>VIO slot number (IBM PowerVM)</entry>
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</row>
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<row>
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<entry><replaceable>prefix</replaceable> <constant>X</constant><replaceable>number</replaceable></entry>
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<entry>VIF interface number (Xen)</entry>
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</row>
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<row>
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<entry>… <constant>b</constant><replaceable>number</replaceable></entry>
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<entry>Broadcom bus (BCMA) core number</entry>
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</row>
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<row>
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<entry>… <constant>u</constant><replaceable>port</replaceable>… [<constant>c</constant><replaceable>config</replaceable>] [<constant>i</constant><replaceable>interface</replaceable>]</entry>
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<entry>USB port number chain</entry>
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</row>
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<row>
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<entry>… <constant>v</constant><replaceable>slot</replaceable></entry>
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<entry>SR-VIO slot number</entry>
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</row>
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<row>
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<entry>… <constant>r</constant><replaceable>slot</replaceable></entry>
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<entry>SR-IOV slot number</entry>
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</row>
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</tbody>
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</tgroup>
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</table>
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<para>The PCI domain is only prepended when it is not 0. All multi-function PCI devices will carry
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the <constant>f</constant><replaceable>function</replaceable> number in the device name, including
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the function 0 device. For non-multi-function devices, the number is suppressed if 0. The port name
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<replaceable>port_name</replaceable> is used, or the port number
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<constant>d</constant><replaceable>dev_port</replaceable> if the name is not known.</para>
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<para>For BCMA devices, the core number is suppressed when 0.</para>
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<para>For USB devices the full chain of port numbers of hubs is composed. If the name gets longer
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than the maximum number of 15 characters, the name is not exported. The usual USB configuration
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number 1 and interface number 0 values are suppressed.</para>
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<para>SR-IOV virtual devices are named based on the name of the parent interface, with a suffix of
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<constant>v</constant> and the virtual device number, with any leading zeros removed. The bus
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number is ignored.</para>
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<para>SR-IOV virtual device representors are named based on the name of the physical device
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interface, with a suffix of <constant>r</constant> and the number of the virtual device that
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is linked to the particular representor, with any leading zeros removed. The physical port
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name and the bus number are ignored.</para>
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<para>In some configurations a parent PCI bridge of a given network controller may be associated
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with a slot. In such case we don't generate this device property to avoid possible naming conflicts.</para>
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<xi:include href="version-info.xml" xpointer="v243"/>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>ID_NET_NAME_PATH=</varname><replaceable>prefix</replaceable><constant>c</constant><replaceable>bus_id</replaceable></term>
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<term><varname>ID_NET_NAME_PATH=</varname><replaceable>prefix</replaceable><constant>a</constant><replaceable>vendor</replaceable><replaceable>model</replaceable><constant>i</constant><replaceable>instance</replaceable></term>
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<term><varname>ID_NET_NAME_PATH=</varname><replaceable>prefix</replaceable><constant>i</constant><replaceable>address</replaceable><constant>n</constant><replaceable>port_name</replaceable></term>
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<term><varname>ID_NET_NAME_PATH=</varname><replaceable>prefix</replaceable><constant>u</constant><replaceable>port</replaceable>…</term>
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<term><varname>ID_NET_NAME_PATH=</varname><replaceable>prefix</replaceable>[<constant>P</constant><replaceable>domain</replaceable>]<constant>p</constant><replaceable>bus</replaceable><constant>s</constant><replaceable>slot</replaceable>[<constant>f</constant><replaceable>function</replaceable>][<constant>n</constant><replaceable>phys_port_name</replaceable>|<constant>d</constant><replaceable>dev_port</replaceable>]</term>
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<term><varname>ID_NET_NAME_PATH=</varname><replaceable>prefix</replaceable>[<constant>P</constant><replaceable>domain</replaceable>]<constant>p</constant><replaceable>bus</replaceable><constant>s</constant><replaceable>slot</replaceable>[<constant>f</constant><replaceable>function</replaceable>][<constant>n</constant><replaceable>phys_port_name</replaceable>|<constant>d</constant><replaceable>dev_port</replaceable>]<constant>b</constant><replaceable>number</replaceable></term>
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<term><varname>ID_NET_NAME_PATH=</varname><replaceable>prefix</replaceable>[<constant>P</constant><replaceable>domain</replaceable>]<constant>p</constant><replaceable>bus</replaceable><constant>s</constant><replaceable>slot</replaceable>[<constant>f</constant><replaceable>function</replaceable>][<constant>n</constant><replaceable>phys_port_name</replaceable>|<constant>d</constant><replaceable>dev_port</replaceable>]<constant>u</constant><replaceable>port</replaceable>…[<constant>c</constant><replaceable>config</replaceable>][<constant>i</constant><replaceable>interface</replaceable>]</term>
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<listitem><para>This property describes the device installation location. Different schemes are
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used depending on the bus type, as described in the table below. For BCMA and USB devices, PCI path
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information must known, and the full name consists of the prefix, PCI slot identifier, and USB or
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BCMA location. The first two parts are denoted as "…" in the table below.</para>
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<table>
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<title>Path naming schemes</title>
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<tgroup cols='2'>
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<thead>
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<row>
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<entry>Format</entry>
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<entry>Description</entry>
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</row>
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</thead>
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<tbody>
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<row>
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<entry><replaceable>prefix</replaceable> <constant>c</constant><replaceable>bus_id</replaceable></entry>
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<entry>CCW or grouped CCW device identifier</entry>
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</row>
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<row>
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<entry><replaceable>prefix</replaceable> <constant>a</constant><replaceable>vendor</replaceable> <replaceable>model</replaceable> <constant>i</constant><replaceable>instance</replaceable></entry>
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<entry>ACPI path names for ARM64 platform devices</entry>
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</row>
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<row>
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<entry><replaceable>prefix</replaceable> <constant>i</constant><replaceable>address</replaceable> <constant>n</constant><replaceable>port_name</replaceable></entry>
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<entry>Netdevsim (simulated networking device) device number and port name</entry>
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</row>
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<row>
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<entry><replaceable>prefix</replaceable> [<constant>P</constant><replaceable>domain</replaceable>] <constant>p</constant><replaceable>bus</replaceable> <constant>s</constant><replaceable>slot</replaceable> [<constant>f</constant><replaceable>function</replaceable>] [<constant>n</constant><replaceable>phys_port_name</replaceable> | <constant>d</constant><replaceable>dev_port</replaceable>]</entry>
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<entry>PCI geographical location</entry>
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</row>
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<row>
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<entry>… <constant>b</constant><replaceable>number</replaceable></entry>
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<entry>Broadcom bus (BCMA) core number</entry>
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</row>
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<row>
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<entry>… <constant>u</constant><replaceable>port</replaceable>… [<constant>c</constant><replaceable>config</replaceable>] [<constant>i</constant><replaceable>interface</replaceable>]</entry>
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<entry>USB port number chain</entry>
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</row>
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</tbody>
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</tgroup>
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</table>
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<para>CCW and grouped CCW devices are found in IBM System Z mainframes. Any leading zeros and
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dots are suppressed.</para>
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<para>For PCI, BCMA, and USB devices, the same rules as described above for slot naming are
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used.</para>
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<xi:include href="version-info.xml" xpointer="v243"/>
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</listitem>
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</varlistentry>
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</variablelist>
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</refsect1>
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<refsect1>
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<title>History</title>
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||
<para>The following "naming schemes" have been defined (which may be chosen at system boot-up time via
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the <varname>net.naming_scheme=</varname> kernel command line switch, see above):</para>
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<variablelist>
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<varlistentry>
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<term><constant>v238</constant></term>
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<listitem><para>This is the naming scheme that was implemented in systemd 238.</para>
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<xi:include href="version-info.xml" xpointer="v243"/></listitem>
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</varlistentry>
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<varlistentry>
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<term><constant>v239</constant></term>
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<listitem><para>Naming was changed for virtual network interfaces created with SR-IOV and NPAR and
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for devices where the PCI network controller device does not have a slot number associated.</para>
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||
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<para>SR-IOV virtual devices are named based on the name of the parent interface, with a suffix of
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<literal>v<replaceable>port</replaceable></literal>, where <replaceable>port</replaceable> is the
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virtual device number. Previously those virtual devices were named as if completely independent.
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</para>
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<para>The ninth and later NPAR virtual devices are named following the scheme used for the first
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eight NPAR partitions. Previously those devices were not renamed and the kernel default
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("eth<replaceable>N</replaceable>") was used.</para>
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<para>Names are also generated for PCI devices where the PCI network controller device does not
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have an associated slot number itself, but one of its parents does. Previously those devices were
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not renamed and the kernel default was used.</para>
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||
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||
<xi:include href="version-info.xml" xpointer="v243"/>
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||
</listitem>
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</varlistentry>
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<varlistentry>
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<term><constant>v240</constant></term>
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<listitem><para>The <literal>ib</literal> prefix and stable names for infiniband devices are
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||
introduced. Previously those devices were not renamed.</para>
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||
|
||
<para>The ACPI index field (used in <varname>ID_NET_NAME_ONBOARD=</varname>) is now also used when
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0.</para>
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<para>A new naming policy <varname>NamePolicy=keep</varname> was introduced. With this policy, if
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the network device name was already set by userspace, the device will not be renamed
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again. Previously, this naming policy applied implicitly, and now it must be explicitly
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requested. Effectively, this means that network devices will be renamed according to the
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configuration, even if they have been renamed already, if <constant>keep</constant> is not
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specified as the naming policy in the <filename index="false">.link</filename> file. See
|
||
<citerefentry><refentrytitle>systemd.link</refentrytitle><manvolnum>5</manvolnum></citerefentry>
|
||
for a description of <varname>NamePolicy=</varname>.</para>
|
||
|
||
<xi:include href="version-info.xml" xpointer="v243"/></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><constant>v241</constant></term>
|
||
|
||
<listitem><para><option>MACAddressPolicy=persistent</option> was extended to set MAC addresses
|
||
based on the device name. Previously addresses were only based on the
|
||
<varname index="false">ID_NET_NAME_*</varname> attributes, which meant that interface names would
|
||
never be generated for virtual devices. Now a persistent address will be generated for most
|
||
devices, including in particular bridges.</para>
|
||
|
||
<para>Note: when userspace does not set a MAC address for a bridge device, the kernel will
|
||
initially assign a random address, and then change it when the first device is enslaved to the
|
||
bridge. With this naming policy change, bridges get a persistent MAC address based on the bridge
|
||
name instead of the first enslaved device.</para>
|
||
|
||
<xi:include href="version-info.xml" xpointer="v243"/></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><constant>v243</constant></term>
|
||
|
||
<listitem><para>Support for renaming netdevsim (simulated networking) devices was added. Previously
|
||
those devices were not renamed.</para>
|
||
|
||
<para>Previously two-letter interface type prefix was prepended to
|
||
<varname>ID_NET_LABEL_ONBOARD=</varname>. This is not done anymore.</para>
|
||
|
||
<xi:include href="version-info.xml" xpointer="v243"/></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><constant>v245</constant></term>
|
||
|
||
<listitem><para>When
|
||
<citerefentry><refentrytitle>systemd-nspawn</refentrytitle><manvolnum>1</manvolnum></citerefentry>
|
||
derives the name for the host side of the network interface created with
|
||
<option>--network-veth</option> from the container name it previously simply truncated the result
|
||
at 15 characters if longer (since that's the maximum length for network interface names). From now
|
||
on, for any interface name that would be longer than 15 characters the last 4 characters are set to
|
||
a 24bit hash value of the full interface name. This way network interface name collisions between
|
||
multiple similarly named containers (who only differ in container name suffix) should be less
|
||
likely (but still possible, since the 24bit hash value is very small).</para>
|
||
|
||
<xi:include href="version-info.xml" xpointer="v245"/></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><constant>v247</constant></term>
|
||
|
||
<listitem><para>When a PCI slot is associated with a PCI bridge that has multiple child network
|
||
controllers, the same value of the <varname>ID_NET_NAME_SLOT</varname> property might be derived
|
||
for those controllers. This would cause a naming conflict if the property is selected as the device
|
||
name. Now, we detect this situation and don't produce the <varname>ID_NET_NAME_SLOT</varname>
|
||
property.</para>
|
||
|
||
<xi:include href="version-info.xml" xpointer="v247"/></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><constant>v249</constant></term>
|
||
|
||
<listitem><para>PCI hotplug slot names for the s390 PCI driver are a hexadecimal representation
|
||
of the <filename>function_id</filename> device attribute. This attribute is now used to build the
|
||
<varname>ID_NET_NAME_SLOT</varname>. Before that, all slot names were parsed as decimal
|
||
numbers, which could either result in an incorrect value of the <varname>ID_NET_NAME_SLOT</varname>
|
||
property or none at all.</para>
|
||
|
||
<para>Some firmware and hypervisor implementations report unreasonably high numbers for the
|
||
on-board index. To prevent the generation of bogus on-board interface names, index numbers greater
|
||
than 16381 (2¹⁴-1) were ignored. For s390 PCI devices index values up to 65535 (2¹⁶-1) are valid.
|
||
To account for that, the limit was increased to 65535.</para>
|
||
|
||
<para>The udev rule <varname>NAME=</varname> replaces <literal>:</literal>,
|
||
<literal>/</literal>, and <literal>%</literal> with an underscore (<literal>_</literal>), and
|
||
refuses strings which contain only numerics.</para>
|
||
|
||
<xi:include href="version-info.xml" xpointer="v249"/>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><constant>v250</constant></term>
|
||
|
||
<listitem><para>Added naming scheme for Xen netfront "vif" interfaces based on the guest side
|
||
VIF number set from the Xen config (or the interface index in AWS EC2).</para>
|
||
|
||
<xi:include href="version-info.xml" xpointer="v250"/>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><constant>v251</constant></term>
|
||
|
||
<listitem><para>Since version <constant>v247</constant> we no longer set
|
||
<varname>ID_NET_NAME_SLOT</varname> if we detect that a PCI device associated with a slot is a PCI
|
||
bridge as that would create naming conflict when there are more child devices on that bridge. Now,
|
||
this is relaxed and we will use slot information to generate the name based on it but only if
|
||
the PCI device has multiple functions. This is safe because distinct function number is a part of
|
||
the device name for multifunction devices.</para>
|
||
|
||
<xi:include href="version-info.xml" xpointer="v251"/>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><constant>v252</constant></term>
|
||
|
||
<listitem><para>Added naming scheme for platform devices with devicetree aliases.</para>
|
||
|
||
<xi:include href="version-info.xml" xpointer="v252"/>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><constant>v253</constant></term>
|
||
|
||
<listitem><para>Set <varname>ID_NET_NAME_PATH</varname> for usb devices not connected via a PCI bus.</para>
|
||
|
||
<xi:include href="version-info.xml" xpointer="v253"/>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><constant>v254</constant></term>
|
||
|
||
<listitem><para>Naming was changed for SR-IOV virtual device representors, optionally settable at
|
||
compilation time. The <literal>r<replaceable>slot</replaceable></literal> suffix was added to
|
||
differentiate SR-IOV virtual device representors attached to a single physical device interface.
|
||
Because of a mistake, this scheme was <emphasis>not the default scheme for systemd version
|
||
254</emphasis>.</para>
|
||
|
||
<xi:include href="version-info.xml" xpointer="v255"/>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><constant>v255</constant></term>
|
||
|
||
<listitem><para>Naming was changed for SR-IOV virtual device representors to enable the
|
||
change introduced in <constant>v254</constant> by default.</para>
|
||
|
||
<xi:include href="version-info.xml" xpointer="v255"/>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
</variablelist>
|
||
|
||
<para>Note that <constant>latest</constant> may be used to denote the latest scheme known (to this
|
||
particular version of systemd).</para>
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>Limiting the use of specific sysfs attributes</title>
|
||
|
||
<para>When creating names for network cards, some naming schemes use data from sysfs populated
|
||
by the kernel. This means that although a specific naming scheme in udev is picked,
|
||
the network card's name can still change when a new kernel version adds a new sysfs attribute.
|
||
For example if kernel starts setting the <constant>phys_port_name</constant>, udev will append the
|
||
"<constant>n</constant><replaceable>phys_port_name</replaceable>" suffix to the device name.</para>
|
||
|
||
<variablelist>
|
||
<varlistentry>
|
||
<term><varname>ID_NET_NAME_ALLOW=</varname><replaceable>BOOL</replaceable></term>
|
||
|
||
<listitem><para>This udev property sets a fallback policy for reading a sysfs attribute.
|
||
If set to <constant>0</constant> udev will not read any sysfs attribute by default, unless it is
|
||
explicitly allowlisted, see below. If set to <constant>1</constant> udev can use any sysfs attribute
|
||
unless it is explicitly forbidden. The default value is <constant>1</constant>.</para>
|
||
|
||
<xi:include href="version-info.xml" xpointer="v256"/>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>ID_NET_NAME_ALLOW_<replaceable>sysfsattr</replaceable>=<replaceable>BOOL</replaceable></varname></term>
|
||
|
||
<listitem><para>This udev property explicitly states if udev shall use the specified
|
||
<replaceable>sysfsattr</replaceable>, when composing the device name.</para>
|
||
|
||
<xi:include href="version-info.xml" xpointer="v256"/>
|
||
</listitem>
|
||
</varlistentry>
|
||
</variablelist>
|
||
|
||
<para>With these options, users can set an allowlist or denylist for sysfs attributes. To create
|
||
an allowlist, the user needs to set <varname>ID_NET_NAME_ALLOW=0</varname> for the device and then list
|
||
the allowed attributes with the
|
||
<varname>ID_NET_NAME_ALLOW_<replaceable>sysfsattr</replaceable>=1</varname>
|
||
options. In case of a denylist, the user needs to provide the list of denied attributes with
|
||
the <varname>ID_NET_NAME_ALLOW_<replaceable>sysfsattr</replaceable>=0</varname> options.</para>
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>Examples</title>
|
||
|
||
<example>
|
||
<title>Using <command>udevadm test-builtin</command> to display device properties</title>
|
||
|
||
<programlisting>$ udevadm test-builtin net_id /sys/class/net/enp0s31f6
|
||
...
|
||
Using default interface naming scheme 'v243'.
|
||
ID_NET_NAMING_SCHEME=v243
|
||
ID_NET_NAME_MAC=enx54ee75cb1dc0
|
||
ID_OUI_FROM_DATABASE=Wistron InfoComm(Kunshan)Co.,Ltd.
|
||
ID_NET_NAME_PATH=enp0s31f6
|
||
...</programlisting>
|
||
</example>
|
||
|
||
<example>
|
||
<title>PCI Ethernet card with firmware index "1"</title>
|
||
|
||
<programlisting>ID_NET_NAME_ONBOARD=eno1
|
||
ID_NET_NAME_ONBOARD_LABEL=Ethernet Port 1
|
||
</programlisting>
|
||
</example>
|
||
|
||
<example>
|
||
<title>PCI Ethernet card in hotplug slot with firmware index number</title>
|
||
|
||
<programlisting># /sys/devices/pci0000:00/0000:00:1c.3/0000:05:00.0/net/ens1
|
||
ID_NET_NAME_MAC=enx000000000466
|
||
ID_NET_NAME_PATH=enp5s0
|
||
ID_NET_NAME_SLOT=ens1</programlisting>
|
||
</example>
|
||
|
||
<example>
|
||
<title>PCI Ethernet multi-function card with 2 ports</title>
|
||
|
||
<programlisting># /sys/devices/pci0000:00/0000:00:1c.0/0000:02:00.0/net/enp2s0f0
|
||
ID_NET_NAME_MAC=enx78e7d1ea46da
|
||
ID_NET_NAME_PATH=enp2s0f0
|
||
|
||
# /sys/devices/pci0000:00/0000:00:1c.0/0000:02:00.1/net/enp2s0f1
|
||
ID_NET_NAME_MAC=enx78e7d1ea46dc
|
||
ID_NET_NAME_PATH=enp2s0f1</programlisting>
|
||
</example>
|
||
|
||
<example>
|
||
<title>PCI WLAN card</title>
|
||
|
||
<programlisting># /sys/devices/pci0000:00/0000:00:1c.1/0000:03:00.0/net/wlp3s0
|
||
ID_NET_NAME_MAC=wlx0024d7e31130
|
||
ID_NET_NAME_PATH=wlp3s0</programlisting>
|
||
</example>
|
||
|
||
<example>
|
||
<title>PCI IB host adapter with 2 ports</title>
|
||
|
||
<programlisting># /sys/devices/pci0000:00/0000:00:03.0/0000:15:00.0/net/ibp21s0f0
|
||
ID_NET_NAME_PATH=ibp21s0f0
|
||
|
||
# /sys/devices/pci0000:00/0000:00:03.0/0000:15:00.1/net/ibp21s0f1
|
||
ID_NET_NAME_PATH=ibp21s0f1</programlisting>
|
||
</example>
|
||
|
||
<example>
|
||
<title>USB built-in 3G modem</title>
|
||
|
||
<programlisting># /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4/2-1.4:1.6/net/wwp0s29u1u4i6
|
||
ID_NET_NAME_MAC=wwx028037ec0200
|
||
ID_NET_NAME_PATH=wwp0s29u1u4i6</programlisting>
|
||
</example>
|
||
|
||
<example>
|
||
<title>USB Android phone</title>
|
||
|
||
<programlisting># /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.0/net/enp0s29u1u2
|
||
ID_NET_NAME_MAC=enxd626b3450fb5
|
||
ID_NET_NAME_PATH=enp0s29u1u2</programlisting>
|
||
</example>
|
||
|
||
<example>
|
||
<title>s390 grouped CCW interface</title>
|
||
|
||
<programlisting># /sys/devices/css0/0.0.0007/0.0.f5f0/group_device/net/encf5f0
|
||
ID_NET_NAME_MAC=enx026d3c00000a
|
||
ID_NET_NAME_PATH=encf5f0</programlisting>
|
||
</example>
|
||
|
||
<example>
|
||
<title>Set an allowlist for reading sysfs attributes for network card naming</title>
|
||
|
||
<programlisting><filename>/etc/udev/hwdb.d/50-net-naming-allowlist.hwdb</filename>
|
||
net:naming:drvirtio_net:*
|
||
ID_NET_NAME_ALLOW=0
|
||
ID_NET_NAME_ALLOW_ACPI_INDEX=1
|
||
ID_NET_NAME_ALLOW_ADDR_ASSIGN_TYPE=1
|
||
ID_NET_NAME_ALLOW_ADDRESS=1
|
||
ID_NET_NAME_ALLOW_ARI_ENABLED=1
|
||
ID_NET_NAME_ALLOW_DEV_PORT=1
|
||
ID_NET_NAME_ALLOW_FUNCTION_ID=1
|
||
ID_NET_NAME_ALLOW_IFLINK=1
|
||
ID_NET_NAME_ALLOW_INDEX=1
|
||
ID_NET_NAME_ALLOW_LABEL=1
|
||
ID_NET_NAME_ALLOW_PHYS_PORT_NAME=1
|
||
ID_NET_NAME_ALLOW_TYPE=1</programlisting>
|
||
</example>
|
||
|
||
<example>
|
||
<title>Set a denylist so that specified sysfs attribute are ignored</title>
|
||
|
||
<programlisting><filename>/etc/udev/hwdb.d/50-net-naming-denylist.hwdb</filename>
|
||
net:naming:drvirtio_net:*
|
||
ID_NET_NAME_ALLOW=1
|
||
ID_NET_NAME_ALLOW_DEV_PORT=0
|
||
ID_NET_NAME_ALLOW_PHYS_PORT_NAME=0
|
||
</programlisting>
|
||
</example>
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>See Also</title>
|
||
<para><simplelist type="inline">
|
||
<member><citerefentry><refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum></citerefentry></member>
|
||
<member><citerefentry><refentrytitle>udevadm</refentrytitle><manvolnum>8</manvolnum></citerefentry></member>
|
||
<member><ulink url="https://systemd.io/PREDICTABLE_INTERFACE_NAMES">Predictable Network Interface Names</ulink></member>
|
||
<member><citerefentry><refentrytitle>systemd-nspawn</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
|
||
</simplelist></para>
|
||
</refsect1>
|
||
|
||
</refentry>
|