man/systemd.netdev.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">
   4
   5 <!--
   6   This file is part of systemd.
   7
   8   Copyright 2013 Tom Gundersen
   9
  10   systemd is free software; you can redistribute it and/or modify it
  11   under the terms of the GNU Lesser General Public License as published by
  12   the Free Software Foundation; either version 2.1 of the License, or
  13   (at your option) any later version.
  14
  15   systemd is distributed in the hope that it will be useful, but
  16   WITHOUT ANY WARRANTY; without even the implied warranty of
  17   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18   Lesser General Public License for more details.
  19
  20   You should have received a copy of the GNU Lesser General Public License
  21   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  22 -->
  23
  24 <refentry id="systemd.netdev" conditional='ENABLE_NETWORKD'>
  25
  26         <refentryinfo>
  27                 <title>systemd.network</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.netdev</refentrytitle>
  42                 <manvolnum>5</manvolnum>
  43         </refmeta>
  44
  45         <refnamediv>
  46                 <refname>systemd.netdev</refname>
  47                 <refpurpose>Virtual Network Device configuration</refpurpose>
  48         </refnamediv>
  49
  50         <refsynopsisdiv>
  51                 <para><filename><replaceable>netdev</replaceable>.netdev</filename></para>
  52         </refsynopsisdiv>
  53
  54         <refsect1>
  55                 <title>Description</title>
  56
  57                 <para>Network setup is performed by
  58                 <citerefentry><refentrytitle>systemd-networkd</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
  59                 </para>
  60
  61                 <para>Virtual Network Device files must have the extension
  62                 <filename>.netdev</filename>; other extensions are ignored. Virtual
  63                 network devices are created as soon as networkd is started. If a netdev
  64                 with the specified name already exists, networkd will use that as-is
  65                 rather than create its own. Note that the settings of the pre-existing
  66                 netdev will not be changed by networkd.</para>
  67
  68                 <para>The <filename>.netdev</filename> files are read from the files located in the
  69                 system network directory <filename>/usr/lib/systemd/network</filename>,
  70                 the volatile runtime network directory
  71                 <filename>/run/systemd/network</filename> and the local administration
  72                 network directory <filename>/etc/systemd/network</filename>.
  73                 All configuration files are collectively sorted and processed in lexical order,
  74                 regardless of the directories in which they live. However, files with
  75                 identical filenames replace each other. Files in
  76                 <filename>/etc</filename> have the highest priority, files in
  77                 <filename>/run</filename> take precedence over files with the same
  78                 name in <filename>/usr/lib</filename>. This can be used to override a
  79                 system-supplied configuration file with a local file if needed; a symlink in
  80                 <filename>/etc</filename> with the same name as a configuration file in
  81                 <filename>/usr/lib</filename>, pointing to <filename>/dev/null</filename>,
  82                 disables the configuration file entirely.</para>
  83
  84         </refsect1>
  85
  86         <refsect1>
  87                 <title>Supported netdev kinds</title>
  88
  89                 <para>The following kinds of virtual network devices may be configured in <filename>.netdev</filename> files:</para>
  90
  91                 <table>
  92                         <title>Supported kinds of virtual network devices</title>
  93
  94                         <tgroup cols='2'>
  95                                 <colspec colname='kind' />
  96                                 <colspec colname='explanation' />
  97                                 <thead><row>
  98                                         <entry>Kind</entry>
  99                                         <entry>Description</entry>
 100                                 </row></thead>
 101                                 <tbody>
 102                                         <row><entry><varname>bond</varname></entry>
 103                                         <entry>A bond device is an aggregation of all its slave devices. See <ulink url="https://www.kernel.org/doc/Documentation/networking/bonding.txt">Linux Ethernet Bonding Driver HOWTO</ulink> for details.Local configuration</entry></row>
 104
 105                                         <row><entry><varname>bridge</varname></entry>
 106                                         <entry>A bridge devcie is a software switch, each of its slave devices and the bridge itself are ports of the switch.</entry></row>
 107
 108                                         <row><entry><varname>dummy</varname></entry>
 109                                         <entry>A dummy device drops all packets sent to it.</entry></row>
 110
 111                                         <row><entry><varname>gre</varname></entry>
 112                                         <entry>A Level 3 GRE tunnel over IPv4. See <ulink url="https://tools.ietf.org/html/rfc2784">RFC 2784</ulink> for details.</entry></row>
 113
 114                                         <row><entry><varname>gretap</varname></entry>
 115                                         <entry>A Level 2 GRE tunnel over IPv4.</entry></row>
 116
 117                                         <row><entry><varname>ip6gre</varname></entry>
 118                                         <entry>A Level 3 GRE tunnel over IPv6.</entry></row>
 119
 120                                         <row><entry><varname>ip6tnl</varname></entry>
 121                                         <entry>An IPv4 or IPv6 tunnel over IPv6</entry></row>
 122
 123                                         <row><entry><varname>ip6gretap</varname></entry>
 124                                         <entry>An Level 2 GRE tunnel over IPv6.</entry></row>
 125
 126                                         <row><entry><varname>ipip</varname></entry>
 127                                         <entry>An IPv4 over IPv4 tunnel.</entry></row>
 128
 129                                         <row><entry><varname>ipvlan</varname></entry>
 130                                         <entry>An ipvlan device is a stacked device which receives packets from its underlying device based on IP address filtering.</entry></row>
 131
 132                                         <row><entry><varname>macvlan</varname></entry>
 133                                         <entry>A macvlan device is a stacked device which receives packets from its underlying device based on MAC address filtering.</entry></row>
 134
 135                                         <row><entry><varname>sit</varname></entry>
 136                                         <entry>An IPv6 over IPv4 tunnel.</entry></row>
 137
 138                                         <row><entry><varname>tap</varname></entry>
 139                                         <entry>A persistent Level 2 tunnel between a network device and a device node.</entry></row>
 140
 141                                         <row><entry><varname>tun</varname></entry>
 142                                         <entry>A persistent Level 3 tunnel between a network device and a device node.</entry></row>
 143
 144                                         <row><entry><varname>veth</varname></entry>
 145                                         <entry>An ethernet tunnel between a pair of network devices.</entry></row>
 146
 147                                         <row><entry><varname>vlan</varname></entry>
 148                                         <entry>A VLAN is a stacked device which receives packets from its underlying device based on VLAN tagging. See <ulink url="http://www.ieee802.org/1/pages/802.1Q.html">IEEE 802.1Q</ulink> for details.</entry></row>
 149
 150                                         <row><entry><varname>vti</varname></entry>
 151                                         <entry>An IPv4 over IPSec tunnel.</entry></row>
 152
 153                                         <row><entry><varname>vxlan</varname></entry>
 154                                         <entry>A virtual extensible LAN (vxlan), for connecting Cloud computing deployments.</entry></row>
 155                                 </tbody>
 156                         </tgroup>
 157                 </table>
 158
 159         </refsect1>
 160
 161         <refsect1>
 162                 <title>[Match] Section Options</title>
 163
 164                 <para>A virtual network device is only created if the
 165                 <literal>[Match]</literal> section matches the current
 166                 environment, or if the section is empty. The following keys are accepted:</para>
 167
 168                         <variablelist class='network-directives'>
 169                                 <varlistentry>
 170                                         <term><varname>Host=</varname></term>
 171                                         <listitem>
 172                                                 <para>Matches against the hostname or machine ID of the
 173                                                 host. See <literal>ConditionHost=</literal> in
 174                                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 175                                                 for details.
 176                                                 </para>
 177                                         </listitem>
 178                                 </varlistentry>
 179                                 <varlistentry>
 180                                         <term><varname>Virtualization=</varname></term>
 181                                         <listitem>
 182                                                 <para>Checks whether the system is executed in a virtualized
 183                                                 environment and optionally test whether it is a specific
 184                                                 implementation. See <literal>ConditionVirtualization=</literal> in
 185                                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 186                                                 for details.
 187                                                 </para>
 188                                         </listitem>
 189                                 </varlistentry>
 190                                 <varlistentry>
 191                                         <term><varname>KernelCommandLine=</varname></term>
 192                                         <listitem>
 193                                                 <para>Checks whether a specific kernel command line option is
 194                                                 set (or if prefixed with the exclamation mark unset). See
 195                                                 <literal>ConditionKernelCommandLine=</literal> in
 196                                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 197                                                 for details.
 198                                                 </para>
 199                                         </listitem>
 200                                 </varlistentry>
 201                                 <varlistentry>
 202                                         <term><varname>Architecture=</varname></term>
 203                                         <listitem>
 204                                                 <para>Checks whether the system is running on a specific
 205                                                 architecture. See <literal>ConditionArchitecture=</literal> in
 206                                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 207                                                 for details.
 208                                                 </para>
 209                                         </listitem>
 210                                 </varlistentry>
 211                         </variablelist>
 212
 213         </refsect1>
 214
 215         <refsect1>
 216                 <title>[NetDev] Section Options</title>
 217
 218                         <para>The <literal>[NetDev]</literal> section accepts the following
 219                         keys:</para>
 220
 221                         <variablelist class='network-directives'>
 222                                 <varlistentry>
 223                                         <term><varname>Description=</varname></term>
 224                                         <listitem>
 225                                                 <para>A free-form description of the netdev.
 226                                                 </para>
 227                                         </listitem>
 228                                 </varlistentry>
 229                                 <varlistentry>
 230                                         <term><varname>Name=</varname></term>
 231                                         <listitem>
 232                                                 <para>The interface name used when creating the
 233                                                 netdev. This option is compulsory.</para>
 234                                         </listitem>
 235                                 </varlistentry>
 236                                 <varlistentry>
 237                                         <term><varname>Kind=</varname></term>
 238                                         <listitem>
 239                                                 <para>The netdev kind. This option is compulsory. See the <literal>Supported netdev kinds</literal> section
 240                                                 for the valid keys.</para>
 241                                         </listitem>
 242                                 </varlistentry>
 243                                 <varlistentry>
 244                                         <term><varname>MTUBytes=</varname></term>
 245                                         <listitem>
 246                                                 <para>The maximum transmission unit in bytes to
 247                                                 set for the device. The usual suffixes K, M, G,
 248                                                 are supported and are understood to the base of
 249                                                 1024. This key is not currently suported for
 250                                                 <literal>tun</literal> or <literal>tap</literal> devices.
 251                                                 </para>
 252                                         </listitem>
 253                                 </varlistentry>
 254                                 <varlistentry>
 255                                         <term><varname>MACAddress=</varname></term>
 256                                         <listitem>
 257                                                 <para>The MAC address to use for the device.
 258                                                 If none is given, one is generated based on
 259                                                 the interface name and the
 260                                                 <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
 261                                                 This key is not currently suported for <literal>tun</literal> or <literal>tap</literal> devices.
 262                                                 </para>
 263                                         </listitem>
 264                                 </varlistentry>
 265                         </variablelist>
 266         </refsect1>
 267
 268         <refsect1>
 269                 <title>[VLAN] Section Options</title>
 270
 271                         <para>The <literal>[VLAN]</literal> section only applies for netdevs of kind <literal>vlan</literal>,
 272                         and accepts the following key:</para>
 273
 274                         <variablelist class='network-directives'>
 275                                 <varlistentry>
 276                                         <term><varname>Id=</varname></term>
 277                                         <listitem>
 278                                                 <para>The VLAN ID to use. An integer in the range 0–4094.
 279                                                 This option is compulsory.</para>
 280                                         </listitem>
 281                                 </varlistentry>
 282                         </variablelist>
 283
 284         </refsect1>
 285
 286         <refsect1>
 287                 <title>[MACVLAN] Section Options</title>
 288
 289                         <para>The <literal>[MACVLAN]</literal> section only applies for netdevs of kind
 290                         <literal>macvlan</literal>, and accepts the following key:</para>
 291
 292                         <variablelist class='network-directives'>
 293                                 <varlistentry>
 294                                         <term><varname>Mode=</varname></term>
 295                                         <listitem>
 296                                                 <para>The MACVLAN mode to use. The supported options are
 297                                                 <literal>private</literal>, <literal>vepa</literal>,
 298                                                 <literal>bridge</literal> and <literal>passthru</literal>.
 299                                                 </para>
 300                                         </listitem>
 301                                 </varlistentry>
 302                         </variablelist>
 303
 304         </refsect1>
 305
 306         <refsect1>
 307                 <title>[IPVLAN] Section Options</title>
 308
 309                         <para>The <literal>[IPVLAN]</literal> section only applies for netdevs of kind
 310                         <literal>ipvlan</literal>, and accepts the following key:</para>
 311
 312                         <variablelist class='network-directives'>
 313                                 <varlistentry>
 314                                         <term><varname>Mode=</varname></term>
 315                                         <listitem>
 316                                                 <para>The IPVLAN mode to use. The supported options are
 317                                                 <literal>L2</literal> and <literal>L3</literal>.
 318                                                 </para>
 319                                         </listitem>
 320                                 </varlistentry>
 321                         </variablelist>
 322
 323         </refsect1>
 324
 325         <refsect1>
 326                 <title>[VXLAN] Section Options</title>
 327                         <para>The <literal>[VXLAN]</literal> section only applies for netdevs of kind
 328                         <literal>vxlan</literal>, and accepts the following key:</para>
 329
 330                         <variablelist class='network-directives'>
 331                                 <varlistentry>
 332                                         <term><varname>Id=</varname></term>
 333                                         <listitem>
 334                                                 <para>The VXLAN ID to use.</para>
 335                                         </listitem>
 336                                 </varlistentry>
 337                                 <varlistentry>
 338                                         <term><varname>Group=</varname></term>
 339                                         <listitem>
 340                                                 <para>An assigned multicast group IP address.</para>
 341                                         </listitem>
 342                                 </varlistentry>
 343                                 <varlistentry>
 344                                         <term><varname>TOS=</varname></term>
 345                                         <listitem>
 346                                                 <para>The Type Of Service byte value for a vxlan interface.</para>
 347                                         </listitem>
 348                                 </varlistentry>
 349                                 <varlistentry>
 350                                         <term><varname>TTL=</varname></term>
 351                                         <listitem>
 352                                                 <para>A fixed Time To Live N on Virtual eXtensible Local Area Network packets.
 353                                                 N is a number in the range 1-255. 0 is a special value meaning that packets
 354                                                 inherit the TTL value.</para>
 355                                         </listitem>
 356                                 </varlistentry>
 357                                 <varlistentry>
 358                                         <term><varname>MacLearning=</varname></term>
 359                                         <listitem>
 360                                                 <para>A boolean. When true, enables dynamic MAC learning
 361                                                 to discover remote MAC addresses.</para>
 362                                         </listitem>
 363                                 </varlistentry>
 364                                 <varlistentry>
 365                                         <term><varname>FDBAgeingSec=</varname></term>
 366                                         <listitem>
 367                                                 <para>The lifetime of Forwarding Database entry learnt by the kernel in seconds.</para>
 368                                         </listitem>
 369                                 </varlistentry>
 370                                 <varlistentry>
 371                                         <term><varname>ARPProxy=</varname></term>
 372                                         <listitem>
 373                                                 <para>A boolean. When true, enables ARP proxy.</para>
 374                                         </listitem>
 375                                 </varlistentry>
 376                                 <varlistentry>
 377                                         <term><varname>L2MissNotification=</varname></term>
 378                                         <listitem>
 379                                                 <para>A boolean. When true, enables netlink LLADDR miss notifications.</para>
 380                                         </listitem>
 381                                 </varlistentry>
 382                                 <varlistentry>
 383                                         <term><varname>L3MissNotification=</varname></term>
 384                                         <listitem>
 385                                                 <para>A boolean. When true, enables netlink IP ADDR miss notifications.</para>
 386                                         </listitem>
 387                                 </varlistentry>
 388                                 <varlistentry>
 389                                         <term><varname>RouteShortCircuit=</varname></term>
 390                                         <listitem>
 391                                                 <para>A boolean. When true route short circuit is turned on.</para>
 392                                         </listitem>
 393                                 </varlistentry>
 394                         </variablelist>
 395         </refsect1>
 396         <refsect1>
 397                 <title>[Tunnel] Section Options</title>
 398
 399                         <para>The <literal>[Tunnel]</literal> section only applies for netdevs of kind
 400                         <literal>ipip</literal>, <literal>sit</literal>, <literal>gre</literal>, <literal>gretap</literal>,
 401                         <literal>ip6gre</literal>, <literal>ip6gretap</literal>, <literal>vti</literal> and <literal>ip6tnl</literal>
 402                         and accepts the following keys:</para>
 403
 404                         <variablelist class='network-directives'>
 405                                 <varlistentry>
 406                                         <term><varname>Local=</varname></term>
 407                                         <listitem>
 408                                                 <para>A static local address for tunneled packets.
 409                                                 It must be an address on another interface of this host.</para>
 410                                         </listitem>
 411                                 </varlistentry>
 412                                 <varlistentry>
 413                                         <term><varname>Remote=</varname></term>
 414                                         <listitem>
 415                                                 <para>The remote endpoint of the tunnel.</para>
 416                                         </listitem>
 417                                 </varlistentry>
 418                                 <varlistentry>
 419                                         <term><varname>TOS=</varname></term>
 420                                         <listitem>
 421                                                 <para>The Type Of Service byte value for a tunnel interface.
 422                                                 For details about the TOS see the
 423                                                 <ulink url="http://tools.ietf.org/html/rfc1349">
 424                                                 Type of Service in the Internet Protocol Suite
 425                                                 </ulink> document.
 426                                                 </para>
 427                                         </listitem>
 428                                 </varlistentry>
 429                                 <varlistentry>
 430                                         <term><varname>TTL=</varname></term>
 431                                         <listitem>
 432                                                 <para>A fixed Time To Live N on tunneled packets.
 433                                                 N is a number in the range 1-255. 0 is a special value meaning that packets
 434                                                 inherit the TTL value. The default value for IPv4 tunnels is: inherit.
 435                                                 The default value for IPv6 tunnels is: 64.</para>
 436                                         </listitem>
 437                                 </varlistentry>
 438                                 <varlistentry>
 439                                         <term><varname>DiscoverPathMTU=</varname></term>
 440                                         <listitem>
 441                                                 <para>A boolean. When true, enables Path MTU Discovery on the tunnel.</para>
 442                                         </listitem>
 443                                 </varlistentry>
 444                                 <varlistentry>
 445                                   <term><varname>Mode=</varname></term>
 446                                   <listitem>
 447                                     <para>An <literal>ip6tnl</literal> tunnels can have three modes
 448                                     <literal>ip6ip6</literal> for IPv6 over IPv6,
 449                                     <literal>ipip6</literal> for IPv4 over IPv6 or
 450                                     <literal>any</literal> for either.
 451                                     </para>
 452                                   </listitem>
 453                                 </varlistentry>
 454                         </variablelist>
 455         </refsect1>
 456         <refsect1>
 457                 <title>[Peer] Section Options</title>
 458
 459                         <para>The <literal>[Peer]</literal> section only applies for netdevs of kind <literal>veth</literal>
 460                         and accepts the following key:</para>
 461
 462                         <variablelist class='network-directives'>
 463                                 <varlistentry>
 464                                         <term><varname>Name=</varname></term>
 465                                         <listitem>
 466                                                 <para>The interface name used when creating the netdev.
 467                                                 This option is compulsory.</para>
 468                                         </listitem>
 469                                 </varlistentry>
 470                                 <varlistentry>
 471                                         <term><varname>MACAddress=</varname></term>
 472                                         <listitem>
 473                                                 <para>The peer MACAddress, if not set it is generated in the same
 474                                                 way as the MAC address of the main interface.</para>
 475                                         </listitem>
 476                                 </varlistentry>
 477                         </variablelist>
 478         </refsect1>
 479         <refsect1>
 480                 <title>[Tun] Section Options</title>
 481
 482                         <para>The <literal>[Tun]</literal> section only applies for netdevs of kind
 483                         <literal>tun</literal>, and accepts the following keys:</para>
 484
 485                         <variablelist class='network-directives'>
 486                                 <varlistentry>
 487                                         <term><varname>OneQueue=</varname></term>
 488                                         <listitem><para>Takes a boolean argument. Configures whether
 489                                         all packets are queued at the device (enabled), or a fixed number
 490                                         of packets are queued at the device and the rest at the
 491                                         <literal>qdisc</literal>. Defaults to <literal>no</literal>.</para>
 492                                         </listitem>
 493                                 </varlistentry>
 494                                 <varlistentry>
 495                                         <term><varname>MultiQueue=</varname></term>
 496                                         <listitem><para>Takes a boolean argument. Configures whether to
 497                                         use multiple file descriptors (queues) to parallelize packets
 498                                         sending and receiving. Defaults to <literal>no</literal>.</para>
 499                                         </listitem>
 500                                 </varlistentry>
 501                                 <varlistentry>
 502                                         <term><varname>PacketInfo=</varname></term>
 503                                         <listitem><para>Takes a boolean argument. Configures whether packets
 504                                         should be prepened with four extra bytes (two flag bytes and two
 505                                         protocol bytes). If disabled it indicates that the packets will be
 506                                         pure IP packets. Defaults to <literal>no</literal>.</para>
 507                                         </listitem>
 508                                 </varlistentry>
 509                                 <varlistentry>
 510                                         <term><varname>User=</varname></term>
 511                                         <listitem><para>User to grant access to the <filename>/dev/net/tun</filename>
 512                                         device.</para>
 513                                         </listitem>
 514                                 </varlistentry>
 515                                 <varlistentry>
 516                                         <term><varname>Group=</varname></term>
 517                                         <listitem><para>Group to grant access to the <filename>/dev/net/tun</filename>
 518                                         device.</para>
 519                                         </listitem>
 520                                 </varlistentry>
 521
 522                         </variablelist>
 523
 524         </refsect1>
 525
 526         <refsect1>
 527                 <title>[Tap] Section Options</title>
 528
 529                         <para>The <literal>[Tap]</literal> section only applies for netdevs of kind
 530                         <literal>tap</literal>, and accepts the same keys as the
 531                         <literal>[Tun]</literal> section.</para>
 532         </refsect1>
 533
 534         <refsect1>
 535                 <title>[Bond] Section Options</title>
 536
 537                         <para>The <literal>[Bond]</literal> section accepts the following
 538                         key:</para>
 539
 540                         <variablelist class='network-directives'>
 541                                 <varlistentry>
 542                                         <term><varname>Mode=</varname></term>
 543                                         <listitem>
 544                                           <para>Specifies one of the bonding policies. The default is
 545                                           <literal>balance-rr</literal> (round robin). Possible values are
 546                                                 <literal>balance-rr</literal>,
 547                                                 <literal>active-backup</literal>,
 548                                                 <literal>balance-xor</literal>,
 549                                                 <literal>broadcast</literal>,
 550                                                 <literal>802.3ad</literal>,
 551                                                 <literal>balance-tlb</literal>, and
 552                                                 <literal>balance-alb</literal>.
 553                                           </para>
 554                                         </listitem>
 555                                 </varlistentry>
 556
 557                                 <varlistentry>
 558                                   <term><varname>TransmitHashPolicy=</varname></term>
 559                                   <listitem>
 560                                     <para>Selects the transmit hash policy to use for slave selection in
 561                                     balance-xor, 802.3ad, and tlb modes. Possible values are
 562                                     <literal>layer2</literal>,
 563                                     <literal>layer3+4</literal>,
 564                                     <literal>layer2+3</literal>,
 565                                     <literal>encap2+3</literal>,
 566                                     <literal>802.3ad</literal>, and
 567                                     <literal>encap3+4</literal>.
 568                                     </para>
 569                                   </listitem>
 570                                 </varlistentry>
 571
 572                                 <varlistentry>
 573                                   <term><varname>LACPTransmitRate=</varname></term>
 574                                   <listitem>
 575                                     <para>Specifies the rate with which link partner
 576                                     transmits Link Aggregation Control Protocol Data Unit packets
 577                                     in 802.3ad mode. Possible values are
 578                                     <literal>slow</literal>, which requests partner to transmit LACPDUs every 30 seconds, and
 579                                     <literal>fast</literal>, which requests partner to transmit LACPDUs every second.
 580                                     The default value is <literal>slow</literal>.</para>
 581                                   </listitem>
 582                                 </varlistentry>
 583
 584                                 <varlistentry>
 585                                   <term><varname>MIIMonitorSec=</varname></term>
 586                                   <listitem>
 587                                     <para>Specifies the frequency that Media Independent Interface link
 588                                     monitoring will occur. A value of zero disables MII link monitoring.
 589                                     This values is rounded down to the nearest millisecond. The default
 590                                     value is 0.</para>
 591                                   </listitem>
 592                                 </varlistentry>
 593
 594                                 <varlistentry>
 595                                   <term><varname>UpDelaySec=</varname></term>
 596                                   <listitem>
 597                                     <para>Specifies the delay before a link is enabled after a link up
 598                                     status has been detected. This value is rounded down to a multiple of
 599                                     MIIMonitorSec. The default value is 0.</para>
 600                                   </listitem>
 601                                 </varlistentry>
 602
 603                                 <varlistentry>
 604                                   <term><varname>DownDelaySec=</varname></term>
 605                                   <listitem>
 606                                     <para>Specifies the delay before a link is disabled after a link down
 607                                     status has been detected. This value is rounded down to a multiple of
 608                                     MIIMonitorSec. The default value is 0.</para>
 609                                   </listitem>
 610                                 </varlistentry>
 611
 612                         </variablelist>
 613         </refsect1>
 614
 615         <refsect1>
 616                 <title>Example</title>
 617                 <example>
 618                         <title>/etc/systemd/network/bridge.netdev</title>
 619
 620                         <programlisting>[NetDev]
 621 Name=bridge0
 622 Kind=bridge</programlisting>
 623                 </example>
 624
 625                 <example>
 626                         <title>/etc/systemd/network/vlan1.netdev</title>
 627
 628                         <programlisting>[Match]
 629 Virtualization=no
 630
 631 [NetDev]
 632 Name=vlan1
 633 Kind=vlan
 634
 635 [VLAN]
 636 Id=1</programlisting>
 637                 </example>
 638                 <example>
 639                         <title>/etc/systemd/network/ipip.netdev</title>
 640                         <programlisting>[NetDev]
 641 Name=ipip-tun
 642 Kind=ipip
 643 MTUBytes=1480
 644
 645 [Tunnel]
 646 Local=192.168.223.238
 647 Remote=192.169.224.239
 648 TTL=64</programlisting>
 649                 </example>
 650                 <example>
 651                   <title>/etc/systemd/network/tap.netdev</title>
 652                   <programlisting>[NetDev]
 653 Name=tap-test
 654 Kind=tap
 655
 656 [Tap]
 657 MultiQueue=true
 658 PacketInfo=true</programlisting> </example>
 659
 660                 <example>
 661                         <title>/etc/systemd/network/sit.netdev</title>
 662                         <programlisting>[NetDev]
 663 Name=sit-tun
 664 Kind=sit
 665 MTUBytes=1480
 666
 667 [Tunnel]
 668 Local=10.65.223.238
 669 Remote=10.65.223.239</programlisting>
 670                 </example>
 671
 672                 <example>
 673                         <title>/etc/systemd/network/gre.netdev</title>
 674                         <programlisting>[NetDev]
 675 Name=gre-tun
 676 Kind=gre
 677 MTUBytes=1480
 678
 679 [Tunnel]
 680 Local=10.65.223.238
 681 Remote=10.65.223.239</programlisting>
 682                 </example>
 683
 684                 <example>
 685                         <title>/etc/systemd/network/vti.netdev</title>
 686
 687                         <programlisting>[NetDev]
 688 Name=vti-tun
 689 Kind=vti
 690 MTUBytes=1480
 691
 692 [Tunnel]
 693 Local=10.65.223.238
 694 Remote=10.65.223.239</programlisting>
 695                 </example>
 696
 697                 <example>
 698                         <title>/etc/systemd/network/veth.netdev</title>
 699                         <programlisting>[NetDev]
 700 Name=veth-test
 701 Kind=veth
 702
 703 [Peer]
 704 Name=veth-peer</programlisting>
 705                 </example>
 706
 707                 <example>
 708                         <title>/etc/systemd/network/dummy.netdev</title>
 709                         <programlisting>[NetDev]
 710 Name=dummy-test
 711 Kind=dummy
 712 MACAddress=12:34:56:78:9a:bc</programlisting>
 713                 </example>
 714
 715         </refsect1>
 716         <refsect1>
 717                 <title>See Also</title>
 718                 <para>
 719                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 720                         <citerefentry><refentrytitle>systemd-networkd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 721                         <citerefentry><refentrytitle>systemd.link</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 722                         <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 723                 </para>
 724         </refsect1>
 725
 726 </refentry>