man/systemd-networkd.service.xml

   1 <?xml version='1.0'?> <!--*-nxml-*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
   3         "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
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   8   Copyright 2013 Tom Gundersen
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  23
  24 <refentry id="systemd-networkd.service" conditional='ENABLE_NETWORKD'>
  25
  26         <refentryinfo>
  27                 <title>systemd-networkd.service</title>
  28                 <productname>systemd</productname>
  29
  30                 <authorgroup>
  31                         <author>
  32                                 <contrib>Developer</contrib>
  33                                 <firstname>Tom</firstname>
  34                                 <surname>Gundersen</surname>
  35                                 <email>teg@jklm.no</email>
  36                         </author>
  37                 </authorgroup>
  38         </refentryinfo>
  39
  40         <refmeta>
  41                 <refentrytitle>systemd-networkd.service</refentrytitle>
  42                 <manvolnum>8</manvolnum>
  43         </refmeta>
  44
  45         <refnamediv>
  46                 <refname>systemd-networkd.service</refname>
  47                 <refname>systemd-networkd</refname>
  48                 <refpurpose>Network manager</refpurpose>
  49         </refnamediv>
  50
  51         <refsynopsisdiv>
  52                 <para><filename>systemd-networkd.service</filename></para>
  53                 <para><filename>/usr/lib/systemd/systemd-networkd</filename></para>
  54         </refsynopsisdiv>
  55
  56         <refsect1>
  57                 <title>Description</title>
  58
  59                 <para><command>systemd-networkd</command> is a system
  60                 service that manages networks. It detects and configures
  61                 network devices as they appear, as well as creating virtual
  62                 network devices.</para>
  63
  64                 <para>To configure low-level link settings independently of
  65                 networks, see
  66                 <citerefentry><refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum></citerefentry>
  67                 .</para>
  68
  69                 <para>Network configurations applied before networkd is started
  70                 are not removed, and static configuration applied by networkd
  71                 are not removed when networkd exits. This ensures restarting
  72                 networkd does not cut the network connection, and, in particular,
  73                 that it is safe to transition between the initrd and the real root,
  74                 and back.</para>
  75         </refsect1>
  76
  77         <refsect1><title>Configuration Files</title>
  78                 <para>The configuration files are read from the files located in the
  79                 system network directory <filename>/usr/lib/systemd/network</filename>,
  80                 the volatile runtime network directory
  81                 <filename>/run/systemd/network</filename> and the local administration
  82                 network directory <filename>/etc/systemd/network</filename>.
  83                 All configuration files are collectively sorted and processed in lexical order,
  84                 regardless of the directories in which they live. However, files with
  85                 identical filenames replace each other. Files in
  86                 <filename>/etc</filename> have the highest priority, files in
  87                 <filename>/run</filename> take precedence over files with the same
  88                 name in <filename>/usr/lib</filename>. This can be used to override a
  89                 system-supplied configuration file with a local file if needed; a symlink in
  90                 <filename>/etc</filename> with the same name as a configuration file in
  91                 <filename>/usr/lib</filename>, pointing to <filename>/dev/null</filename>,
  92                 disables the configuration file entirely.</para>
  93
  94                 <refsect2><title>Virtual Network Devices</title>
  95                         <para>Virtual Network Device files must have the extension
  96                         <filename>.netdev</filename>; other extensions are ignored. Virtual
  97                         network devices are created as soon as networkd is started.</para>
  98
  99                         <para>The <literal>[NetDev]</literal> section accepts the following
 100                         keys:</para>
 101
 102                         <variablelist class='network-directives'>
 103                                 <varlistentry>
 104                                         <term><varname>Name</varname></term>
 105                                         <listitem>
 106                                                 <para>The interface name used when creating the
 107                                                 bridge. This option is compulsory.</para>
 108                                         </listitem>
 109                                 </varlistentry>
 110                                 <varlistentry>
 111                                         <term><varname>Kind</varname></term>
 112                                         <listitem>
 113                                                 <para>The netdev kind. Currently, <literal>bridge</literal>,
 114                                                 <literal>bond</literal> and <literal>vlan</literal>
 115                                                 are supported. This option is compulsory.</para>
 116                                         </listitem>
 117                                 </varlistentry>
 118                         </variablelist>
 119
 120                         <para>The <literal>[VLAN]</literal> section only applies for netdevs of kind <literal>vlan</literal>,
 121                         and accepts the following key:</para>
 122
 123                         <variablelist class='network-directives'>
 124                                 <varlistentry>
 125                                         <term><varname>Id</varname></term>
 126                                         <listitem>
 127                                                 <para>The VLAN ID to use. An integer in the range 0–4094.
 128                                                 This option is compulsory.</para>
 129                                         </listitem>
 130                                 </varlistentry>
 131                         </variablelist>
 132
 133                 </refsect2>
 134
 135                 <refsect2><title>Networks</title>
 136                         <para>Network files must have the extension <filename>.network</filename>;
 137                         other extensions are ignored. Networks are applied to links whenever the links
 138                         appear.</para>
 139
 140                         <para>The network file contains a <literal>[Match]</literal> section,
 141                         which determines if a given network file may be applied to a given device;
 142                         and a <literal>[Network]</literal> section specifying how the device should
 143                         be configured. The first (in lexical order) of the network files that
 144                         matches a given device is applied.</para>
 145
 146                         <para>A network file is said to match a device if each of the entries in the
 147                         <literal>[Match]</literal> section matches, or if the section is empty.
 148                         The following keys are accepted:</para>
 149
 150                         <variablelist class='network-directives'>
 151                                 <varlistentry>
 152                                         <term><varname>MACAddress</varname></term>
 153                                         <listitem>
 154                                                 <para>The hardware address.</para>
 155                                         </listitem>
 156                                 </varlistentry>
 157                                 <varlistentry>
 158                                         <term><varname>Path</varname></term>
 159                                         <listitem>
 160                                                 <para>The persistent path, as exposed by the udev
 161                                                 property <literal>ID_PATH</literal>.</para>
 162                                         </listitem>
 163                                 </varlistentry>
 164                                 <varlistentry>
 165                                         <term><varname>Driver</varname></term>
 166                                         <listitem>
 167                                                 <para>The driver currently bound to the device, as
 168                                                 exposed by the udev property <literal>DRIVER</literal>
 169                                                 of its parent device.
 170                                                 </para>
 171                                         </listitem>
 172                                 </varlistentry>
 173                                 <varlistentry>
 174                                         <term><varname>Type</varname></term>
 175                                         <listitem>
 176                                                 <para>The device type, as exposed by the udev property
 177                                                 <literal>DEVTYPE</literal>.</para>
 178                                         </listitem>
 179                                 </varlistentry>
 180                                 <varlistentry>
 181                                         <term><varname>Name</varname></term>
 182                                         <listitem>
 183                                                 <para>The device name, as exposed by the udev property
 184                                                 <literal>INTERFACE</literal>.</para>
 185                                         </listitem>
 186                                 </varlistentry>
 187                         </variablelist>
 188
 189                         <para>The <literal>[Network]</literal> section accepts the following keys:</para>
 190
 191                         <variablelist class='network-directives'>
 192                                 <varlistentry>
 193                                         <term><varname>Description</varname></term>
 194                                         <listitem>
 195                                                 <para>A description of the device. This is only used for
 196                                                 presentation purposes.</para>
 197                                         </listitem>
 198                                 </varlistentry>
 199                                 <varlistentry>
 200                                         <term><varname>DHCP</varname></term>
 201                                         <listitem>
 202                                                 <para>A boolean. When true, enables basic DHCPv4 support.</para>
 203                                         </listitem>
 204                                 </varlistentry>
 205                                 <varlistentry>
 206                                         <term><varname>Address</varname></term>
 207                                         <listitem>
 208                                                 <para>A static IPv4 or IPv6 address and its prefix length,
 209                                                 separated by a <literal>/</literal> character. The format of the address must
 210                                                 be as described in
 211                                                 <citerefentry><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 212                                                 . This is a short-hand for an [Address] section only containing an Address key (see below).</para>
 213                                         </listitem>
 214                                 </varlistentry>
 215                                 <varlistentry>
 216                                         <term><varname>Gateway</varname></term>
 217                                         <listitem>
 218                                                 <para>The gateway address, which must be in the format described in
 219                                                 <citerefentry><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 220                                                 . This is a short-hand for a [Route] section only containing a Gateway key.</para>
 221                                         </listitem>
 222                                 </varlistentry>
 223                                 <varlistentry>
 224                                         <term><varname>DNS</varname></term>
 225                                         <listitem>
 226                                                 <para>A DNS server address, which must be in the format described in
 227                                                 <citerefentry><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 228                                                 .</para>
 229                                         </listitem>
 230                                 </varlistentry>
 231                                 <varlistentry>
 232                                         <term><varname>Bridge</varname></term>
 233                                         <listitem>
 234                                                 <para>The name of the bridge to add the link to.</para>
 235                                         </listitem>
 236                                 </varlistentry>
 237                                 <varlistentry>
 238                                         <term><varname>Bond</varname></term>
 239                                         <listitem>
 240                                                 <para>The name of the bond to add the link to.</para>
 241                                         </listitem>
 242                                 </varlistentry>
 243                                 <varlistentry>
 244                                         <term><varname>VLAN</varname></term>
 245                                         <listitem>
 246                                                 <para>The name of a VLAN to create on the link. This option
 247                                                 may be specified more than once.</para>
 248                                         </listitem>
 249                                 </varlistentry>
 250                         </variablelist>
 251
 252                         <para>The <literal>[Address]</literal> section accepts the following keys:</para>
 253
 254                         <variablelist class='network-directives'>
 255                                 <varlistentry>
 256                                         <term><varname>Address</varname></term>
 257                                         <listitem>
 258                                                 <para>As in the <literal>[Network]</literal> section. This key is mandatory.</para>
 259                                         </listitem>
 260                                 </varlistentry>
 261                                 <varlistentry>
 262                                         <term><varname>Broadcast</varname></term>
 263                                         <listitem>
 264                                                 <para>The broadcast address, which must be in the format described in
 265                                                 <citerefentry><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 266                                                 . This key only applies to IPv4 addresses. If it is not given, it is
 267                                                 derived from the <literal>Address</literal> key.</para>
 268                                         </listitem>
 269                                 </varlistentry>
 270                                 <varlistentry>
 271                                         <term><varname>Label</varname></term>
 272                                         <listitem>
 273                                                 <para>An address label.</para>
 274                                         </listitem>
 275                                 </varlistentry>
 276                         </variablelist>
 277
 278                         <para>The <literal>[Route]</literal> section accepts the following keys:</para>
 279
 280                         <variablelist class='network-directives'>
 281                                 <varlistentry>
 282                                         <term><varname>Gateway</varname></term>
 283                                         <listitem>
 284                                                 <para>As in the <literal>[Network]</literal> section. This key is mandatory.</para>
 285                                         </listitem>
 286                                 </varlistentry>
 287                                 <varlistentry>
 288                                         <term><varname>Destination</varname></term>
 289                                         <listitem>
 290                                                 <para>The destination prefix of the route. Possibly followed by a slash and the
 291                                                 prefixlength, if ommitted a full-length host route is assumed.</para>
 292                                         </listitem>
 293                                 </varlistentry>
 294                         </variablelist>
 295
 296                         <para>The <literal>[DHCPv4]</literal> section accepts the following keys:</para>
 297
 298                         <variablelist class='network-directives'>
 299                                 <varlistentry>
 300                                         <term><varname>UseDNS</varname></term>
 301                                         <listitem>
 302                                                 <para>When true (the default), the DNS servers received from the DHCP server will
 303                                                 be used and take precedence over any statically configured ones.</para>
 304                                         </listitem>
 305                                 </varlistentry>
 306                                 <varlistentry>
 307                                         <term><varname>UseMTU</varname></term>
 308                                         <listitem>
 309                                                 <para>When true, the interface maximum transmission unit from the DHCP server will
 310                                                 be used on the current link. Defaults to false.</para>
 311                                         </listitem>
 312                                 </varlistentry>
 313                                 <varlistentry>
 314                                         <term><varname>UseHostname</varname></term>
 315                                         <listitem>
 316                                                 <para>When true (the default), the hostname received from the DHCP server
 317                                                 will be used as the transient hostname.</para>
 318                                         </listitem>
 319                                 </varlistentry>
 320                                 <varlistentry>
 321                                         <term><varname>CriticalConnection</varname></term>
 322                                         <listitem>
 323                                                 <para>When true, the connection will never be torn down even if the DHCP lease
 324                                                 expires. This is contrary to the DHCP specification, but may be the best choice
 325                                                 if, say, the root filesystem relies on this connection. Defaults to false.</para>
 326                                         </listitem>
 327                                 </varlistentry>
 328                        </variablelist>
 329
 330                 </refsect2>
 331         </refsect1>
 332
 333         <refsect1>
 334                 <title>See Also</title>
 335                 <para>
 336                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 337                         <citerefentry><refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 338                 </para>
 339         </refsect1>
 340
 341 </refentry>