man/systemd.netdev.xml

   1 <?xml version='1.0'?> <!--*-nxml-*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   3   "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   4 <!-- SPDX-License-Identifier: LGPL-2.1+ -->
   5
   6 <refentry id="systemd.netdev" conditional='ENABLE_NETWORKD'>
   7
   8   <refentryinfo>
   9     <title>systemd.network</title>
  10     <productname>systemd</productname>
  11   </refentryinfo>
  12
  13   <refmeta>
  14     <refentrytitle>systemd.netdev</refentrytitle>
  15     <manvolnum>5</manvolnum>
  16   </refmeta>
  17
  18   <refnamediv>
  19     <refname>systemd.netdev</refname>
  20     <refpurpose>Virtual Network Device configuration</refpurpose>
  21   </refnamediv>
  22
  23   <refsynopsisdiv>
  24     <para><filename><replaceable>netdev</replaceable>.netdev</filename></para>
  25   </refsynopsisdiv>
  26
  27   <refsect1>
  28     <title>Description</title>
  29
  30     <para>Network setup is performed by
  31     <citerefentry><refentrytitle>systemd-networkd</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
  32     </para>
  33
  34     <para>The main Virtual Network Device file must have the extension <filename>.netdev</filename>;
  35     other extensions are ignored. Virtual network devices are created as soon as networkd is
  36     started. If a netdev with the specified name already exists, networkd will use that as-is rather
  37     than create its own. Note that the settings of the pre-existing netdev will not be changed by
  38     networkd.</para>
  39
  40     <para>The <filename>.netdev</filename> files are read from the files located in the system
  41     network directory <filename>/usr/lib/systemd/network</filename>, the volatile runtime network
  42     directory <filename>/run/systemd/network</filename> and the local administration network
  43     directory <filename>/etc/systemd/network</filename>. All configuration files are collectively
  44     sorted and processed in lexical order, regardless of the directories in which they live.
  45     However, files with identical filenames replace each other. Files in <filename>/etc</filename>
  46     have the highest priority, files in <filename>/run</filename> take precedence over files with
  47     the same name in <filename>/usr/lib</filename>. This can be used to override a system-supplied
  48     configuration file with a local file if needed. As a special case, an empty file (file size 0)
  49     or symlink with the same name pointing to <filename>/dev/null</filename> disables the
  50     configuration file entirely (it is "masked").</para>
  51
  52     <para>Along with the netdev file <filename>foo.netdev</filename>, a "drop-in" directory
  53     <filename>foo.netdev.d/</filename> may exist. All files with the suffix <literal>.conf</literal>
  54     from this directory will be parsed after the file itself is parsed. This is useful to alter or
  55     add configuration settings, without having to modify the main configuration file. Each drop-in
  56     file must have appropriate section headers.</para>
  57
  58     <para>In addition to <filename>/etc/systemd/network</filename>, drop-in <literal>.d</literal>
  59     directories can be placed in <filename>/usr/lib/systemd/network</filename> or
  60     <filename>/run/systemd/network</filename> directories. Drop-in files in
  61     <filename>/etc</filename> take precedence over those in <filename>/run</filename> which in turn
  62     take precedence over those in <filename>/usr/lib</filename>. Drop-in files under any of these
  63     directories take precedence over the main netdev file wherever located. (Of course, since
  64     <filename>/run</filename> is temporary and <filename>/usr/lib</filename> is for vendors, it is
  65     unlikely drop-ins should be used in either of those places.)</para>
  66   </refsect1>
  67
  68   <refsect1>
  69     <title>Supported netdev kinds</title>
  70
  71     <para>The following kinds of virtual network devices may be
  72     configured in <filename>.netdev</filename> files:</para>
  73
  74     <table>
  75       <title>Supported kinds of virtual network devices</title>
  76
  77       <tgroup cols='2'>
  78         <colspec colname='kind' />
  79         <colspec colname='explanation' />
  80         <thead><row>
  81           <entry>Kind</entry>
  82           <entry>Description</entry>
  83         </row></thead>
  84         <tbody>
  85           <row><entry><varname>bond</varname></entry>
  86           <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>
  87
  88           <row><entry><varname>bridge</varname></entry>
  89           <entry>A bridge device is a software switch, and each of its slave devices and the bridge itself are ports of the switch.</entry></row>
  90
  91           <row><entry><varname>dummy</varname></entry>
  92           <entry>A dummy device drops all packets sent to it.</entry></row>
  93
  94           <row><entry><varname>gre</varname></entry>
  95           <entry>A Level 3 GRE tunnel over IPv4. See <ulink url="https://tools.ietf.org/html/rfc2784">RFC 2784</ulink> for details.</entry></row>
  96
  97           <row><entry><varname>gretap</varname></entry>
  98           <entry>A Level 2 GRE tunnel over IPv4.</entry></row>
  99
 100           <row><entry><varname>erspan</varname></entry>
 101           <entry>ERSPAN mirrors traffic on one or more source ports and delivers the mirrored traffic to one or more destination ports on another switch. The traffic is encapsulated in generic routing encapsulation (GRE) and is therefore routable across a layer 3 network between the source switch and the destination switch.</entry></row>
 102
 103           <row><entry><varname>ip6gre</varname></entry>
 104           <entry>A Level 3 GRE tunnel over IPv6.</entry></row>
 105
 106           <row><entry><varname>ip6tnl</varname></entry>
 107           <entry>An IPv4 or IPv6 tunnel over IPv6</entry></row>
 108
 109           <row><entry><varname>ip6gretap</varname></entry>
 110           <entry>A Level 2 GRE tunnel over IPv6.</entry></row>
 111
 112           <row><entry><varname>ipip</varname></entry>
 113           <entry>An IPv4 over IPv4 tunnel.</entry></row>
 114
 115           <row><entry><varname>ipvlan</varname></entry>
 116           <entry>An ipvlan device is a stacked device which receives packets from its underlying device based on IP address filtering.</entry></row>
 117
 118           <row><entry><varname>macvlan</varname></entry>
 119           <entry>A macvlan device is a stacked device which receives packets from its underlying device based on MAC address filtering.</entry></row>
 120
 121           <row><entry><varname>macvtap</varname></entry>
 122           <entry>A macvtap device is a stacked device which receives packets from its underlying device based on MAC address filtering.</entry></row>
 123
 124           <row><entry><varname>sit</varname></entry>
 125           <entry>An IPv6 over IPv4 tunnel.</entry></row>
 126
 127           <row><entry><varname>tap</varname></entry>
 128           <entry>A persistent Level 2 tunnel between a network device and a device node.</entry></row>
 129
 130           <row><entry><varname>tun</varname></entry>
 131           <entry>A persistent Level 3 tunnel between a network device and a device node.</entry></row>
 132
 133           <row><entry><varname>veth</varname></entry>
 134           <entry>An Ethernet tunnel between a pair of network devices.</entry></row>
 135
 136           <row><entry><varname>vlan</varname></entry>
 137           <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>
 138
 139           <row><entry><varname>vti</varname></entry>
 140           <entry>An IPv4 over IPSec tunnel.</entry></row>
 141
 142           <row><entry><varname>vti6</varname></entry>
 143           <entry>An IPv6 over IPSec tunnel.</entry></row>
 144
 145           <row><entry><varname>vxlan</varname></entry>
 146           <entry>A virtual extensible LAN (vxlan), for connecting Cloud computing deployments.</entry></row>
 147
 148           <row><entry><varname>geneve</varname></entry>
 149           <entry>A GEneric NEtwork Virtualization Encapsulation (GENEVE) netdev driver.</entry></row>
 150
 151           <row><entry><varname>l2tp</varname></entry>
 152           <entry>A Layer 2 Tunneling Protocol (L2TP) is a tunneling protocol used to support virtual private networks (VPNs) or as part of the delivery of services by ISPs. It does not provide any encryption or confidentiality by itself</entry></row>
 153
 154           <row><entry><varname>vrf</varname></entry>
 155           <entry>A Virtual Routing and Forwarding (<ulink url="https://www.kernel.org/doc/Documentation/networking/vrf.txt">VRF</ulink>) interface to create separate routing and forwarding domains.</entry></row>
 156
 157           <row><entry><varname>vcan</varname></entry>
 158           <entry>The virtual CAN driver (vcan). Similar to the network loopback devices, vcan offers a virtual local CAN interface.</entry></row>
 159
 160           <row><entry><varname>vxcan</varname></entry>
 161           <entry>The virtual CAN tunnel driver (vxcan). Similar to the virtual ethernet driver veth, vxcan implements a local CAN traffic tunnel between two virtual CAN network devices. When creating a vxcan, two vxcan devices are created as pair. When one end receives the packet it appears on its pair and vice versa. The vxcan can be used for cross namespace communication.
 162           </entry></row>
 163
 164           <row><entry><varname>wireguard</varname></entry>
 165           <entry>WireGuard Secure Network Tunnel.</entry></row>
 166
 167           <row><entry><varname>netdevsim</varname></entry>
 168           <entry> A simulator. This simulated networking device is used for testing various networking APIs and at this time is particularly focused on testing hardware offloading related interfaces.</entry></row>
 169
 170           <row><entry><varname>fou</varname></entry>
 171           <entry>Foo-over-UDP tunneling.</entry></row>
 172
 173         </tbody>
 174       </tgroup>
 175     </table>
 176
 177   </refsect1>
 178
 179   <refsect1>
 180     <title>[Match] Section Options</title>
 181
 182     <para>A virtual network device is only created if the
 183     <literal>[Match]</literal> section matches the current
 184     environment, or if the section is empty. The following keys are
 185     accepted:</para>
 186
 187     <variablelist class='network-directives'>
 188       <varlistentry>
 189         <term><varname>Host=</varname></term>
 190         <listitem>
 191           <para>Matches against the hostname or machine ID of the host. See
 192           <literal>ConditionHost=</literal> in
 193           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 194           for details. When prefixed with an exclamation mark (<literal>!</literal>), the result is negated.
 195           If an empty string is assigned, then previously assigned value is cleared.
 196           </para>
 197         </listitem>
 198       </varlistentry>
 199       <varlistentry>
 200         <term><varname>Virtualization=</varname></term>
 201         <listitem>
 202           <para>Checks whether the system is executed in a virtualized environment and optionally test
 203           whether it is a specific implementation. See <literal>ConditionVirtualization=</literal> in
 204           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 205           for details. When prefixed with an exclamation mark (<literal>!</literal>), the result is negated.
 206           If an empty string is assigned, then previously assigned value is cleared.
 207           </para>
 208         </listitem>
 209       </varlistentry>
 210       <varlistentry>
 211         <term><varname>KernelCommandLine=</varname></term>
 212         <listitem>
 213           <para>Checks whether a specific kernel command line option is set. See
 214           <literal>ConditionKernelCommandLine=</literal> in
 215           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 216           for details. When prefixed with an exclamation mark (<literal>!</literal>), the result is negated.
 217           If an empty string is assigned, then previously assigned value is cleared.
 218           </para>
 219         </listitem>
 220       </varlistentry>
 221       <varlistentry>
 222         <term><varname>KernelVersion=</varname></term>
 223         <listitem>
 224           <para>Checks whether the kernel version (as reported by <command>uname -r</command>) matches a
 225           certain expression. See <literal>ConditionKernelVersion=</literal> in
 226           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 227           for details. When prefixed with an exclamation mark (<literal>!</literal>), the result is negated.
 228           If an empty string is assigned, then previously assigned value is cleared.
 229           </para>
 230         </listitem>
 231       </varlistentry>
 232       <varlistentry>
 233         <term><varname>Architecture=</varname></term>
 234         <listitem>
 235           <para>Checks whether the system is running on a specific architecture. See
 236           <literal>ConditionArchitecture=</literal> in
 237           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 238           for details. When prefixed with an exclamation mark (<literal>!</literal>), the result is negated.
 239           If an empty string is assigned, then previously assigned value is cleared.
 240           </para>
 241         </listitem>
 242       </varlistentry>
 243     </variablelist>
 244
 245   </refsect1>
 246
 247   <refsect1>
 248     <title>[NetDev] Section Options</title>
 249
 250       <para>The <literal>[NetDev]</literal> section accepts the
 251       following keys:</para>
 252
 253       <variablelist class='network-directives'>
 254         <varlistentry>
 255           <term><varname>Description=</varname></term>
 256           <listitem>
 257             <para>A free-form description of the netdev.</para>
 258           </listitem>
 259         </varlistentry>
 260         <varlistentry>
 261           <term><varname>Name=</varname></term>
 262           <listitem>
 263             <para>The interface name used when creating the netdev.
 264             This option is compulsory.</para>
 265           </listitem>
 266         </varlistentry>
 267         <varlistentry>
 268           <term><varname>Kind=</varname></term>
 269           <listitem>
 270             <para>The netdev kind. This option is compulsory. See the
 271             <literal>Supported netdev kinds</literal> section for the
 272             valid keys.</para>
 273           </listitem>
 274         </varlistentry>
 275         <varlistentry>
 276           <term><varname>MTUBytes=</varname></term>
 277           <listitem>
 278             <para>The maximum transmission unit in bytes to set for the device. The usual suffixes K, M, G,
 279             are supported and are understood to the base of 1024. For <literal>tun</literal> or
 280             <literal>tap</literal> devices, <varname>MTUBytes=</varname> setting is not currently supported in
 281             <literal>[NetDev]</literal> section. Please specify it in <literal>[Link]</literal> section of
 282             corresponding
 283             <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 284             files.</para>
 285           </listitem>
 286         </varlistentry>
 287         <varlistentry>
 288           <term><varname>MACAddress=</varname></term>
 289           <listitem>
 290             <para>The MAC address to use for the device. For <literal>tun</literal> or <literal>tap</literal>
 291             devices, setting <varname>MACAddress=</varname> in the <literal>[NetDev]</literal> section is not
 292             supported. Please specify it in <literal>[Link]</literal> section of the corresponding
 293             <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 294             file. If this option is not set, <literal>vlan</literal> devices inherit the MAC address of the
 295             physical interface. For other kind of netdevs, if this option is not set, then MAC address is
 296             generated based on the interface name and the
 297             <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
 298             </para>
 299           </listitem>
 300         </varlistentry>
 301       </variablelist>
 302   </refsect1>
 303
 304     <refsect1>
 305     <title>[Bridge] Section Options</title>
 306
 307       <para>The <literal>[Bridge]</literal> section only applies for
 308       netdevs of kind <literal>bridge</literal>, and accepts the
 309       following keys:</para>
 310
 311       <variablelist class='network-directives'>
 312         <varlistentry>
 313           <term><varname>HelloTimeSec=</varname></term>
 314           <listitem>
 315             <para>HelloTimeSec specifies the number of seconds between two hello packets
 316             sent out by the root bridge and the designated bridges. Hello packets are
 317             used to communicate information about the topology throughout the entire
 318             bridged local area network.</para>
 319           </listitem>
 320         </varlistentry>
 321         <varlistentry>
 322           <term><varname>MaxAgeSec=</varname></term>
 323           <listitem>
 324             <para>MaxAgeSec specifies the number of seconds of maximum message age.
 325             If the last seen (received) hello packet is more than this number of
 326             seconds old, the bridge in question will start the takeover procedure
 327             in attempt to become the Root Bridge itself.</para>
 328           </listitem>
 329         </varlistentry>
 330         <varlistentry>
 331           <term><varname>ForwardDelaySec=</varname></term>
 332           <listitem>
 333             <para>ForwardDelaySec specifies the number of seconds spent in each
 334             of the Listening and Learning states before the Forwarding state is entered.</para>
 335           </listitem>
 336         </varlistentry>
 337         <varlistentry>
 338           <term><varname>AgeingTimeSec=</varname></term>
 339           <listitem>
 340             <para>This specifies the number of seconds a MAC Address will be kept in
 341             the forwarding database after having a packet received from this MAC Address.</para>
 342           </listitem>
 343         </varlistentry>
 344         <varlistentry>
 345           <term><varname>Priority=</varname></term>
 346           <listitem>
 347             <para>The priority of the bridge. An integer between 0 and 65535. A lower value
 348             means higher priority. The bridge having the lowest priority will be elected as root bridge.</para>
 349           </listitem>
 350         </varlistentry>
 351         <varlistentry>
 352           <term><varname>GroupForwardMask=</varname></term>
 353           <listitem>
 354             <para>A 16-bit bitmask represented as an integer which allows forwarding of link
 355             local frames with 802.1D reserved addresses (01:80:C2:00:00:0X). A logical AND
 356             is performed between the specified bitmask and the exponentiation of 2^X, the
 357             lower nibble of the last octet of the MAC address. For example, a value of 8
 358             would allow forwarding of frames addressed to 01:80:C2:00:00:03 (802.1X PAE).</para>
 359           </listitem>
 360         </varlistentry>
 361         <varlistentry>
 362           <term><varname>DefaultPVID=</varname></term>
 363           <listitem>
 364             <para>This specifies the default port VLAN ID of a newly attached bridge port.
 365             Set this to an integer in the range 1–4094 or <literal>none</literal> to disable the PVID.</para>
 366           </listitem>
 367         </varlistentry>
 368         <varlistentry>
 369           <term><varname>MulticastQuerier=</varname></term>
 370           <listitem>
 371             <para>Takes a boolean. This setting controls the IFLA_BR_MCAST_QUERIER option in the kernel.
 372             If enabled, the kernel will send general ICMP queries from a zero source address.
 373             This feature should allow faster convergence on startup, but it causes some
 374             multicast-aware switches to misbehave and disrupt forwarding of multicast packets.
 375             When unset, the kernel's default will be used.
 376             </para>
 377           </listitem>
 378         </varlistentry>
 379         <varlistentry>
 380           <term><varname>MulticastSnooping=</varname></term>
 381           <listitem>
 382             <para>Takes a boolean. This setting controls the IFLA_BR_MCAST_SNOOPING option in the kernel.
 383             If enabled, IGMP snooping monitors the Internet Group Management Protocol (IGMP) traffic
 384             between hosts and multicast routers. When unset, the kernel's default will be used.
 385             </para>
 386           </listitem>
 387         </varlistentry>
 388         <varlistentry>
 389           <term><varname>VLANFiltering=</varname></term>
 390           <listitem>
 391             <para>Takes a boolean. This setting controls the IFLA_BR_VLAN_FILTERING option in the kernel.
 392             If enabled, the bridge will be started in VLAN-filtering mode. When unset, the kernel's default will be used.
 393             </para>
 394           </listitem>
 395         </varlistentry>
 396           <varlistentry>
 397           <term><varname>STP=</varname></term>
 398           <listitem>
 399             <para>Takes a boolean. This enables the bridge's Spanning Tree Protocol (STP).
 400             When unset, the kernel's default will be used.
 401             </para>
 402           </listitem>
 403         </varlistentry>
 404       </variablelist>
 405   </refsect1>
 406
 407   <refsect1>
 408     <title>[VLAN] Section Options</title>
 409
 410       <para>The <literal>[VLAN]</literal> section only applies for
 411       netdevs of kind <literal>vlan</literal>, and accepts the
 412       following key:</para>
 413
 414       <variablelist class='network-directives'>
 415         <varlistentry>
 416           <term><varname>Id=</varname></term>
 417           <listitem>
 418             <para>The VLAN ID to use. An integer in the range 0–4094.
 419             This option is compulsory.</para>
 420           </listitem>
 421         </varlistentry>
 422         <varlistentry>
 423           <term><varname>GVRP=</varname></term>
 424           <listitem>
 425             <para>Takes a boolean. The Generic VLAN Registration Protocol (GVRP) is a protocol that
 426             allows automatic learning of VLANs on a network.
 427             When unset, the kernel's default will be used.
 428             </para>
 429           </listitem>
 430         </varlistentry>
 431         <varlistentry>
 432           <term><varname>MVRP=</varname></term>
 433           <listitem>
 434             <para>Takes a boolean. Multiple VLAN Registration Protocol (MVRP) formerly known as GARP VLAN
 435             Registration Protocol (GVRP) is a standards-based Layer 2 network protocol,
 436             for automatic configuration of VLAN information on switches. It was defined
 437             in the 802.1ak amendment to 802.1Q-2005. When unset, the kernel's default will be used.
 438             </para>
 439           </listitem>
 440         </varlistentry>
 441         <varlistentry>
 442           <term><varname>LooseBinding=</varname></term>
 443           <listitem>
 444             <para>Takes a boolean. The VLAN loose binding mode, in which only the operational state is passed
 445             from the parent to the associated VLANs, but the VLAN device state is not changed.
 446             When unset, the kernel's default will be used.</para>
 447           </listitem>
 448         </varlistentry>
 449         <varlistentry>
 450           <term><varname>ReorderHeader=</varname></term>
 451           <listitem>
 452             <para>Takes a boolean. The VLAN reorder header is set VLAN interfaces behave like physical interfaces.
 453             When unset, the kernel's default will be used.</para>
 454           </listitem>
 455         </varlistentry>
 456       </variablelist>
 457   </refsect1>
 458
 459   <refsect1>
 460     <title>[MACVLAN] Section Options</title>
 461
 462     <para>The <literal>[MACVLAN]</literal> section only applies for
 463     netdevs of kind <literal>macvlan</literal>, and accepts the
 464     following key:</para>
 465
 466     <variablelist class='network-directives'>
 467       <varlistentry>
 468         <term><varname>Mode=</varname></term>
 469         <listitem>
 470           <para>The MACVLAN mode to use. The supported options are
 471           <literal>private</literal>,
 472           <literal>vepa</literal>,
 473           <literal>bridge</literal>, and
 474           <literal>passthru</literal>.
 475           </para>
 476         </listitem>
 477       </varlistentry>
 478     </variablelist>
 479
 480   </refsect1>
 481
 482     <refsect1>
 483     <title>[MACVTAP] Section Options</title>
 484
 485     <para>The <literal>[MACVTAP]</literal> section applies for
 486     netdevs of kind <literal>macvtap</literal> and accepts the
 487     same key as <literal>[MACVLAN]</literal>.</para>
 488
 489     </refsect1>
 490
 491   <refsect1>
 492     <title>[IPVLAN] Section Options</title>
 493
 494     <para>The <literal>[IPVLAN]</literal> section only applies for
 495     netdevs of kind <literal>ipvlan</literal>, and accepts the
 496     following key:</para>
 497
 498     <variablelist class='network-directives'>
 499       <varlistentry>
 500         <term><varname>Mode=</varname></term>
 501           <listitem>
 502             <para>The IPVLAN mode to use. The supported options are
 503             <literal>L2</literal>,<literal>L3</literal> and <literal>L3S</literal>.
 504             </para>
 505           </listitem>
 506       </varlistentry>
 507        <varlistentry>
 508         <term><varname>Flags=</varname></term>
 509           <listitem>
 510             <para>The IPVLAN flags to use. The supported options are
 511             <literal>bridge</literal>,<literal>private</literal> and <literal>vepa</literal>.
 512             </para>
 513           </listitem>
 514       </varlistentry>
 515     </variablelist>
 516
 517   </refsect1>
 518
 519   <refsect1>
 520     <title>[VXLAN] Section Options</title>
 521     <para>The <literal>[VXLAN]</literal> section only applies for
 522     netdevs of kind <literal>vxlan</literal>, and accepts the
 523     following keys:</para>
 524
 525     <variablelist class='network-directives'>
 526       <varlistentry>
 527         <term><varname>Id=</varname></term>
 528         <listitem>
 529           <para>The VXLAN ID to use.</para>
 530         </listitem>
 531       </varlistentry>
 532       <varlistentry>
 533         <term><varname>Remote=</varname></term>
 534         <listitem>
 535           <para>Configures destination IP address.</para>
 536         </listitem>
 537       </varlistentry>
 538       <varlistentry>
 539         <term><varname>Local=</varname></term>
 540         <listitem>
 541           <para>Configures local IP address.</para>
 542         </listitem>
 543       </varlistentry>
 544         <varlistentry>
 545         <term><varname>TOS=</varname></term>
 546         <listitem>
 547           <para>The Type Of Service byte value for a vxlan interface.</para>
 548         </listitem>
 549       </varlistentry>
 550       <varlistentry>
 551         <term><varname>TTL=</varname></term>
 552         <listitem>
 553           <para>A fixed Time To Live N on Virtual eXtensible Local
 554           Area Network packets. N is a number in the range 1–255. 0
 555           is a special value meaning that packets inherit the TTL
 556           value.</para>
 557         </listitem>
 558       </varlistentry>
 559       <varlistentry>
 560         <term><varname>MacLearning=</varname></term>
 561         <listitem>
 562           <para>Takes a boolean. When true, enables dynamic MAC learning
 563           to discover remote MAC addresses.</para>
 564         </listitem>
 565       </varlistentry>
 566       <varlistentry>
 567         <term><varname>FDBAgeingSec=</varname></term>
 568         <listitem>
 569           <para>The lifetime of Forwarding Database entry learnt by
 570           the kernel, in seconds.</para>
 571         </listitem>
 572       </varlistentry>
 573       <varlistentry>
 574         <term><varname>MaximumFDBEntries=</varname></term>
 575         <listitem>
 576           <para>Configures maximum number of FDB entries.</para>
 577         </listitem>
 578       </varlistentry>
 579       <varlistentry>
 580         <term><varname>ReduceARPProxy=</varname></term>
 581         <listitem>
 582           <para>Takes a boolean. When true, bridge-connected VXLAN tunnel
 583           endpoint answers ARP requests from the local bridge on behalf
 584           of remote Distributed Overlay Virtual Ethernet
 585           <ulink url="https://en.wikipedia.org/wiki/Distributed_Overlay_Virtual_Ethernet">
 586           (DVOE)</ulink> clients. Defaults to false.</para>
 587         </listitem>
 588       </varlistentry>
 589       <varlistentry>
 590         <term><varname>L2MissNotification=</varname></term>
 591         <listitem>
 592           <para>Takes a boolean. When true, enables netlink LLADDR miss
 593           notifications.</para>
 594         </listitem>
 595       </varlistentry>
 596       <varlistentry>
 597         <term><varname>L3MissNotification=</varname></term>
 598         <listitem>
 599           <para>Takes a boolean. When true, enables netlink IP address miss
 600           notifications.</para>
 601         </listitem>
 602       </varlistentry>
 603       <varlistentry>
 604         <term><varname>RouteShortCircuit=</varname></term>
 605         <listitem>
 606           <para>Takes a boolean. When true, route short circuiting is turned
 607           on.</para>
 608         </listitem>
 609       </varlistentry>
 610       <varlistentry>
 611         <term><varname>UDPChecksum=</varname></term>
 612         <listitem>
 613           <para>Takes a boolean. When true, transmitting UDP checksums when doing VXLAN/IPv4 is turned on.</para>
 614         </listitem>
 615       </varlistentry>
 616       <varlistentry>
 617         <term><varname>UDP6ZeroChecksumTx=</varname></term>
 618         <listitem>
 619           <para>Takes a boolean. When true, sending zero checksums in VXLAN/IPv6 is turned on.</para>
 620         </listitem>
 621       </varlistentry>
 622       <varlistentry>
 623         <term><varname>UDP6ZeroChecksumRx=</varname></term>
 624         <listitem>
 625           <para>Takes a boolean. When true, receiving zero checksums in VXLAN/IPv6 is turned on.</para>
 626         </listitem>
 627       </varlistentry>
 628       <varlistentry>
 629         <term><varname>RemoteChecksumTx=</varname></term>
 630         <listitem>
 631           <para>Takes a boolean. When true, remote transmit checksum offload of VXLAN is turned on.</para>
 632         </listitem>
 633       </varlistentry>
 634       <varlistentry>
 635         <term><varname>RemoteChecksumRx=</varname></term>
 636         <listitem>
 637           <para>Takes a boolean. When true, remote receive checksum offload in VXLAN is turned on.</para>
 638         </listitem>
 639       </varlistentry>
 640     <varlistentry>
 641       <term><varname>GroupPolicyExtension=</varname></term>
 642       <listitem>
 643         <para>Takes a boolean. When true, it enables Group Policy VXLAN extension security label mechanism
 644         across network peers based on VXLAN. For details about the Group Policy VXLAN, see the
 645         <ulink url="https://tools.ietf.org/html/draft-smith-vxlan-group-policy">
 646         VXLAN Group Policy </ulink> document. Defaults to false.</para>
 647       </listitem>
 648     </varlistentry>
 649     <varlistentry>
 650       <term><varname>DestinationPort=</varname></term>
 651       <listitem>
 652         <para>Configures the default destination UDP port on a per-device basis.
 653         If destination port is not specified then Linux kernel default will be used.
 654         Set destination port 4789 to get the IANA assigned value. If not set or if the
 655         destination port is assigned the empty string the default port of 4789 is used.</para>
 656       </listitem>
 657     </varlistentry>
 658     <varlistentry>
 659       <term><varname>PortRange=</varname></term>
 660         <listitem>
 661           <para>Configures VXLAN port range. VXLAN bases source
 662           UDP port based on flow to help the receiver to be able
 663           to load balance based on outer header flow. It
 664           restricts the port range to the normal UDP local
 665           ports, and allows overriding via configuration.</para>
 666         </listitem>
 667       </varlistentry>
 668     <varlistentry>
 669       <term><varname>FlowLabel=</varname></term>
 670         <listitem>
 671           <para>Specifies the flow label to use in outgoing packets.
 672           The valid range is 0-1048575.
 673           </para>
 674         </listitem>
 675       </varlistentry>
 676     </variablelist>
 677   </refsect1>
 678   <refsect1>
 679     <title>[GENEVE] Section Options</title>
 680     <para>The <literal>[GENEVE]</literal> section only applies for
 681     netdevs of kind <literal>geneve</literal>, and accepts the
 682     following keys:</para>
 683
 684     <variablelist class='network-directives'>
 685       <varlistentry>
 686         <term><varname>Id=</varname></term>
 687         <listitem>
 688           <para>Specifies the Virtual Network Identifier (VNI) to use. Ranges [0-16777215].</para>
 689         </listitem>
 690       </varlistentry>
 691       <varlistentry>
 692         <term><varname>Remote=</varname></term>
 693         <listitem>
 694           <para>Specifies the unicast destination IP address to use in outgoing packets.</para>
 695         </listitem>
 696       </varlistentry>
 697       <varlistentry>
 698         <term><varname>TOS=</varname></term>
 699         <listitem>
 700           <para>Specifies the TOS value to use in outgoing packets. Ranges [1-255].</para>
 701         </listitem>
 702       </varlistentry>
 703       <varlistentry>
 704         <term><varname>TTL=</varname></term>
 705         <listitem>
 706           <para>Specifies the TTL value to use in outgoing packets. Ranges [1-255].</para>
 707         </listitem>
 708       </varlistentry>
 709       <varlistentry>
 710         <term><varname>UDPChecksum=</varname></term>
 711         <listitem>
 712           <para>Takes a boolean. When true, specifies if UDP checksum is calculated for transmitted packets over IPv4.</para>
 713         </listitem>
 714       </varlistentry>
 715       <varlistentry>
 716         <term><varname>UDP6ZeroChecksumTx=</varname></term>
 717         <listitem>
 718           <para>Takes a boolean. When true, skip UDP checksum calculation for transmitted packets over IPv6.</para>
 719         </listitem>
 720       </varlistentry>
 721       <varlistentry>
 722         <term><varname>UDP6ZeroChecksumRx=</varname></term>
 723         <listitem>
 724           <para>Takes a boolean. When true, allows incoming UDP packets over IPv6 with zero checksum field.</para>
 725         </listitem>
 726       </varlistentry>
 727     <varlistentry>
 728       <term><varname>DestinationPort=</varname></term>
 729       <listitem>
 730         <para>Specifies destination port. Defaults to 6081. If not set or assigned the empty string, the default
 731         port of 6081 is used.</para>
 732       </listitem>
 733     </varlistentry>
 734     <varlistentry>
 735       <term><varname>FlowLabel=</varname></term>
 736         <listitem>
 737           <para>Specifies the flow label to use in outgoing packets.</para>
 738         </listitem>
 739       </varlistentry>
 740     </variablelist>
 741   </refsect1>
 742   <refsect1>
 743     <title>[L2TP] Section Options</title>
 744     <para>The <literal>[L2TP]</literal> section only applies for
 745     netdevs of kind <literal>l2tp</literal>, and accepts the
 746     following keys:</para>
 747
 748     <variablelist class='network-directives'>
 749       <varlistentry>
 750         <term><varname>TunnelId=</varname></term>
 751         <listitem>
 752           <para>Specifies the tunnel id. The value used must match the <literal>PeerTunnelId=</literal> value being used at the peer.
 753           Ranges a number between 1 and 4294967295). This option is compulsory.</para>
 754         </listitem>
 755       </varlistentry>
 756       <varlistentry>
 757         <term><varname>PeerTunnelId=</varname></term>
 758         <listitem>
 759           <para>Specifies the peer tunnel id. The value used must match the <literal>PeerTunnelId=</literal> value being used at the peer.
 760           Ranges a number between 1 and 4294967295). This option is compulsory.</para>
 761         </listitem>
 762       </varlistentry>
 763       <varlistentry>
 764         <term><varname>Remote=</varname></term>
 765         <listitem>
 766           <para>Specifies the IP address of the remote peer. This option is compulsory.</para>
 767         </listitem>
 768       </varlistentry>
 769       <varlistentry>
 770         <term><varname>Local=</varname></term>
 771         <listitem>
 772           <para>Specifies the IP address of the local interface. Takes an IP address, or the special values
 773           <literal>auto</literal>, <literal>static</literal>, or <literal>dynamic</literal>. When an address
 774           is set, then the local interface must have the address. If <literal>auto</literal>, then one of the
 775           addresses on the local interface is used. Similarly, if <literal>static</literal> or
 776           <literal>dynamic</literal> is set, then one of the static or dynamic addresses on the local
 777           interface is used. Defaults to <literal>auto</literal>.</para>
 778         </listitem>
 779       </varlistentry>
 780       <varlistentry>
 781         <term><varname>EncapsulationType=</varname></term>
 782         <listitem>
 783           <para>Specifies the encapsulation type of the tunnel. Takes one of <literal>udp</literal> or <literal>ip</literal>.</para>
 784         </listitem>
 785       </varlistentry>
 786       <varlistentry>
 787         <term><varname>UDPSourcePort=</varname></term>
 788         <listitem>
 789           <para>Specifies the UDP source port to be used for the tunnel. When UDP encapsulation is selected it's mandotory. Ignored when ip
 790           encapsulation is selected.</para>
 791         </listitem>
 792       </varlistentry>
 793       <varlistentry>
 794         <term><varname>DestinationPort=</varname></term>
 795         <listitem>
 796           <para>Specifies destination port. When UDP encapsulation is selected it's mandotory. Ignored when ip
 797           encapsulation is selected.</para>
 798         </listitem>
 799       </varlistentry>
 800       <varlistentry>
 801         <term><varname>UDPChecksum=</varname></term>
 802         <listitem>
 803           <para>Takes a boolean. When true, specifies if UDP checksum is calculated for transmitted packets over IPv4.</para>
 804         </listitem>
 805       </varlistentry>
 806       <varlistentry>
 807         <term><varname>UDP6ZeroChecksumTx=</varname></term>
 808         <listitem>
 809           <para>Takes a boolean. When true, skip UDP checksum calculation for transmitted packets over IPv6.</para>
 810         </listitem>
 811       </varlistentry>
 812       <varlistentry>
 813         <term><varname>UDP6ZeroChecksumRx=</varname></term>
 814         <listitem>
 815           <para>Takes a boolean. When true, allows incoming UDP packets over IPv6 with zero checksum field.</para>
 816         </listitem>
 817       </varlistentry>
 818     </variablelist>
 819   </refsect1>
 820   <refsect1>
 821     <title>[L2TPSession] Section Options</title>
 822     <para>The <literal>[L2TPSession]</literal> section only applies for
 823     netdevs of kind <literal>l2tp</literal>, and accepts the
 824     following keys:</para>
 825     <variablelist class='network-directives'>
 826       <varlistentry>
 827         <term><varname>Name=</varname></term>
 828         <listitem>
 829           <para>Specifies the name of the sesssion. This option is compulsory.</para>
 830         </listitem>
 831       </varlistentry>
 832       <varlistentry>
 833         <term><varname>SessionId=</varname></term>
 834         <listitem>
 835           <para>Specifies the sesssion id. The value used must match the <literal>SessionId=</literal> value being used at the peer.
 836           Ranges a number between 1 and 4294967295). This option is compulsory.</para>
 837         </listitem>
 838       </varlistentry>
 839       <varlistentry>
 840         <term><varname>PeerSessionId=</varname></term>
 841         <listitem>
 842           <para>Specifies the peer session id. The value used must match the <literal>PeerSessionId=</literal> value being used at the peer.
 843           Ranges a number between 1 and 4294967295). This option is compulsory.</para>
 844         </listitem>
 845       </varlistentry>
 846       <varlistentry>
 847         <term><varname>Layer2SpecificHeader=</varname></term>
 848         <listitem>
 849           <para>Specifies layer2specific header type of the session. One of <literal>none</literal> or <literal>default</literal>. Defaults to <literal>default</literal>.</para>
 850         </listitem>
 851       </varlistentry>
 852     </variablelist>
 853   </refsect1>
 854   <refsect1>
 855     <title>[Tunnel] Section Options</title>
 856
 857     <para>The <literal>[Tunnel]</literal> section only applies for
 858     netdevs of kind
 859     <literal>ipip</literal>,
 860     <literal>sit</literal>,
 861     <literal>gre</literal>,
 862     <literal>gretap</literal>,
 863     <literal>ip6gre</literal>,
 864     <literal>ip6gretap</literal>,
 865     <literal>vti</literal>,
 866     <literal>vti6</literal>,
 867     <literal>ip6tnl</literal>, and
 868     <literal>erspan</literal> and accepts
 869     the following keys:</para>
 870
 871     <variablelist class='network-directives'>
 872       <varlistentry>
 873         <term><varname>Local=</varname></term>
 874         <listitem>
 875           <para>A static local address for tunneled packets. It must be an address on another interface of
 876           this host, or the special value <literal>any</literal>.</para>
 877         </listitem>
 878       </varlistentry>
 879       <varlistentry>
 880         <term><varname>Remote=</varname></term>
 881         <listitem>
 882           <para>The remote endpoint of the tunnel. Takes an IP address or the special value
 883           <literal>any</literal>.</para>
 884         </listitem>
 885       </varlistentry>
 886       <varlistentry>
 887         <term><varname>TOS=</varname></term>
 888         <listitem>
 889           <para>The Type Of Service byte value for a tunnel interface.
 890           For details about the TOS, see the
 891           <ulink url="http://tools.ietf.org/html/rfc1349"> Type of
 892           Service in the Internet Protocol Suite </ulink> document.
 893           </para>
 894         </listitem>
 895       </varlistentry>
 896       <varlistentry>
 897         <term><varname>TTL=</varname></term>
 898         <listitem>
 899           <para>A fixed Time To Live N on tunneled packets. N is a
 900           number in the range 1–255. 0 is a special value meaning that
 901           packets inherit the TTL value. The default value for IPv4
 902           tunnels is: inherit. The default value for IPv6 tunnels is
 903           64.</para>
 904         </listitem>
 905       </varlistentry>
 906       <varlistentry>
 907         <term><varname>DiscoverPathMTU=</varname></term>
 908         <listitem>
 909           <para>Takes a boolean. When true, enables Path MTU Discovery on
 910           the tunnel.</para>
 911         </listitem>
 912       </varlistentry>
 913       <varlistentry>
 914         <term><varname>IPv6FlowLabel=</varname></term>
 915         <listitem>
 916           <para>Configures the 20-bit flow label (see <ulink url="https://tools.ietf.org/html/rfc6437">
 917           RFC 6437</ulink>) field in the IPv6 header (see <ulink url="https://tools.ietf.org/html/rfc2460">
 918           RFC 2460</ulink>), which is used by a node to label packets of a flow.
 919           It is only used for IPv6 tunnels.
 920           A flow label of zero is used to indicate packets that have
 921           not been labeled.
 922           It can be configured to a value in the range 0–0xFFFFF, or be
 923           set to <literal>inherit</literal>, in which case the original flowlabel is used.</para>
 924         </listitem>
 925       </varlistentry>
 926       <varlistentry>
 927         <term><varname>CopyDSCP=</varname></term>
 928         <listitem>
 929           <para>Takes a boolean. When true, the Differentiated Service Code
 930           Point (DSCP) field will be copied to the inner header from
 931           outer header during the decapsulation of an IPv6 tunnel
 932           packet. DSCP is a field in an IP packet that enables different
 933           levels of service to be assigned to network traffic.
 934           Defaults to <literal>no</literal>.
 935           </para>
 936         </listitem>
 937       </varlistentry>
 938       <varlistentry>
 939         <term><varname>EncapsulationLimit=</varname></term>
 940         <listitem>
 941           <para>The Tunnel Encapsulation Limit option specifies how many additional
 942           levels of encapsulation are permitted to be prepended to the packet.
 943           For example, a Tunnel Encapsulation Limit option containing a limit
 944           value of zero means that a packet carrying that option may not enter
 945           another tunnel before exiting the current tunnel.
 946           (see <ulink url="https://tools.ietf.org/html/rfc2473#section-4.1.1"> RFC 2473</ulink>).
 947           The valid range is 0–255 and <literal>none</literal>. Defaults to 4.
 948         </para>
 949         </listitem>
 950       </varlistentry>
 951       <varlistentry>
 952         <term><varname>Key=</varname></term>
 953         <listitem>
 954           <para>The <varname>Key=</varname> parameter specifies the same key to use in
 955           both directions (<varname>InputKey=</varname> and <varname>OutputKey=</varname>).
 956           The <varname>Key=</varname> is either a number or an IPv4 address-like dotted quad.
 957           It is used as mark-configured SAD/SPD entry as part of the lookup key (both in data
 958           and control path) in ip xfrm (framework used to implement IPsec protocol).
 959           See <ulink url="http://man7.org/linux/man-pages/man8/ip-xfrm.8.html">
 960           ip-xfrm — transform configuration</ulink> for details. It is only used for VTI/VTI6,
 961           GRE, GRETAP, and ERSPAN tunnels.</para>
 962         </listitem>
 963       </varlistentry>
 964       <varlistentry>
 965         <term><varname>InputKey=</varname></term>
 966         <listitem>
 967           <para>The <varname>InputKey=</varname> parameter specifies the key to use for input.
 968           The format is same as <varname>Key=</varname>. It is only used for VTI/VTI6, GRE, GRETAP,
 969           and ERSPAN tunnels.</para>
 970         </listitem>
 971       </varlistentry>
 972       <varlistentry>
 973         <term><varname>OutputKey=</varname></term>
 974         <listitem>
 975           <para>The <varname>OutputKey=</varname> parameter specifies the key to use for output.
 976           The format is same as <varname>Key=</varname>. It is only used for VTI/VTI6, GRE, GRETAP,
 977           and ERSPAN tunnels.</para>
 978         </listitem>
 979       </varlistentry>
 980       <varlistentry>
 981         <term><varname>Mode=</varname></term>
 982         <listitem>
 983           <para>An <literal>ip6tnl</literal> tunnel can be in one of three
 984           modes
 985           <literal>ip6ip6</literal> for IPv6 over IPv6,
 986           <literal>ipip6</literal> for IPv4 over IPv6 or
 987           <literal>any</literal> for either.
 988           </para>
 989         </listitem>
 990       </varlistentry>
 991       <varlistentry>
 992         <term><varname>Independent=</varname></term>
 993         <listitem>
 994           <para>Takes a boolean. When true tunnel does not require .network file. Created as "tunnel@NONE".
 995           Defaults to <literal>false</literal>.
 996           </para>
 997         </listitem>
 998       </varlistentry>
 999       <varlistentry>
1000         <term><varname>AllowLocalRemote=</varname></term>
1001         <listitem>
1002           <para>Takes a boolean. When true allows tunnel traffic on <varname>ip6tnl</varname> devices where the remote endpoint is a local host address.
1003           When unset, the kernel's default will be used.
1004           </para>
1005         </listitem>
1006       </varlistentry>
1007       <varlistentry>
1008         <term><varname>FooOverUDP=</varname></term>
1009         <listitem>
1010           <para>Takes a boolean. Specifies whether <varname>FooOverUDP=</varname> tunnel is to be configured.
1011           Defaults to false. For more detail information see
1012           <ulink url="https://lwn.net/Articles/614348">Foo over UDP</ulink></para>
1013         </listitem>
1014       </varlistentry>
1015       <varlistentry>
1016         <term><varname>FOUDestinationPort=</varname></term>
1017         <listitem>
1018           <para>This setting specifies the UDP destination port for encapsulation.
1019           This field is mandatory and is not set by default.</para>
1020         </listitem>
1021       </varlistentry>
1022       <varlistentry>
1023         <term><varname>FOUSourcePort=</varname></term>
1024         <listitem>
1025           <para>This setting specifies the UDP source port for encapsulation. Defaults to <constant>0</constant>
1026           — that is, the source port for packets is left to the network stack to decide.</para>
1027         </listitem>
1028       </varlistentry>
1029       <varlistentry>
1030         <term><varname>Encapsulation=</varname></term>
1031         <listitem>
1032           <para>Accepts the same key as <literal>[FooOverUDP]</literal></para>
1033         </listitem>
1034       </varlistentry>
1035       <varlistentry>
1036         <term><varname>IPv6RapidDeploymentPrefix=</varname></term>
1037         <listitem>
1038           <para>Reconfigure the tunnel for <ulink url="https://tools.ietf.org/html/rfc5569">IPv6 Rapid
1039           Deployment</ulink>, also known as 6rd. The value is an ISP-specific IPv6 prefix with a non-zero length. Only
1040           applicable to SIT tunnels.</para>
1041         </listitem>
1042       </varlistentry>
1043       <varlistentry>
1044         <term><varname>ISATAP=</varname></term>
1045         <listitem>
1046           <para>Takes a boolean. If set, configures the tunnel as Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) tunnel.
1047           Only applicable to SIT tunnels. When unset, the kernel's default will be used.</para>
1048         </listitem>
1049       </varlistentry>
1050       <varlistentry>
1051         <term><varname>SerializeTunneledPackets=</varname></term>
1052         <listitem>
1053           <para>Takes a boolean. If set to yes, then packets are serialized. Only applies for GRE,
1054           GRETAP, and ERSPAN tunnels. When unset, the kernel's default will be used.
1055           </para>
1056         </listitem>
1057       </varlistentry>
1058       <varlistentry>
1059         <term><varname>ERSPANIndex=</varname></term>
1060         <listitem>
1061           <para>Specifies the ERSPAN index field for the interface, an integer in the range 1-1048575 associated with
1062           the ERSPAN traffic's source port and direction. This field is mandatory.
1063           </para>
1064         </listitem>
1065       </varlistentry>
1066     </variablelist>
1067   </refsect1>
1068
1069   <refsect1>
1070     <title>[FooOverUDP] Section Options</title>
1071
1072     <para>The <literal>[FooOverUDP]</literal> section only applies for
1073     netdevs of kind <literal>fou</literal> and accepts the
1074     following keys:</para>
1075
1076     <variablelist class='network-directives'>
1077       <varlistentry>
1078         <term><varname>Protocol=</varname></term>
1079         <listitem>
1080           <para>The <varname>Protocol=</varname> specifies the protocol number of the
1081           packets arriving at the UDP port. This field is mandatory and is not set by default. Valid range is 1-255.</para>
1082         </listitem>
1083       </varlistentry>
1084       <varlistentry>
1085         <term><varname>Encapsulation=</varname></term>
1086         <listitem>
1087           <para>Specifies the encapsulation mechanism used to store networking packets of various protocols inside the UDP packets. Supports the following values:
1088
1089           <literal>FooOverUDP</literal> provides the simplest no frills model of UDP encapsulation, it simply encapsulates
1090           packets directly in the UDP payload.
1091           <literal>GenericUDPEncapsulation</literal> is a generic and extensible encapsulation, it allows encapsulation of packets for any IP
1092           protocol and optional data as part of the encapsulation.
1093           For more detailed information see <ulink url="https://lwn.net/Articles/615044">Generic UDP Encapsulation</ulink>.
1094           Defaults to <literal>FooOverUDP</literal>.
1095           </para>
1096         </listitem>
1097       </varlistentry>
1098       <varlistentry>
1099         <term><varname>Port=</varname></term>
1100         <listitem>
1101           <para>Specifies the port number, where the IP encapsulation packets will arrive. Please take note that the packets
1102           will arrive with the encapsulation will be removed. Then they will be manually fed back into the network stack, and sent ahead
1103           for delivery to the real destination. This option is mandatory.</para>
1104         </listitem>
1105         </varlistentry>
1106       </variablelist>
1107   </refsect1>
1108   <refsect1>
1109     <title>[Peer] Section Options</title>
1110
1111       <para>The <literal>[Peer]</literal> section only applies for
1112       netdevs of kind <literal>veth</literal> and accepts the
1113       following keys:</para>
1114
1115       <variablelist class='network-directives'>
1116         <varlistentry>
1117           <term><varname>Name=</varname></term>
1118           <listitem>
1119             <para>The interface name used when creating the netdev.
1120             This option is compulsory.</para>
1121           </listitem>
1122         </varlistentry>
1123         <varlistentry>
1124           <term><varname>MACAddress=</varname></term>
1125           <listitem>
1126             <para>The peer MACAddress, if not set, it is generated in
1127             the same way as the MAC address of the main
1128             interface.</para>
1129           </listitem>
1130         </varlistentry>
1131       </variablelist>
1132   </refsect1>
1133   <refsect1>
1134   <title>[VXCAN] Section Options</title>
1135       <para>The <literal>[VXCAN]</literal> section only applies for
1136       netdevs of kind <literal>vxcan</literal> and accepts the
1137       following key:</para>
1138
1139       <variablelist class='network-directives'>
1140         <varlistentry>
1141           <term><varname>Peer=</varname></term>
1142           <listitem>
1143             <para>The peer interface name used when creating the netdev.
1144             This option is compulsory.</para>
1145           </listitem>
1146         </varlistentry>
1147       </variablelist>
1148   </refsect1>
1149   <refsect1>
1150     <title>[Tun] Section Options</title>
1151
1152     <para>The <literal>[Tun]</literal> section only applies for
1153     netdevs of kind <literal>tun</literal>, and accepts the following
1154     keys:</para>
1155
1156     <variablelist class='network-directives'>
1157       <varlistentry>
1158         <term><varname>OneQueue=</varname></term>
1159         <listitem><para>Takes a boolean. Configures whether
1160         all packets are queued at the device (enabled), or a fixed
1161         number of packets are queued at the device and the rest at the
1162         <literal>qdisc</literal>. Defaults to
1163         <literal>no</literal>.</para>
1164         </listitem>
1165       </varlistentry>
1166       <varlistentry>
1167         <term><varname>MultiQueue=</varname></term>
1168         <listitem><para>Takes a boolean. Configures whether
1169         to use multiple file descriptors (queues) to parallelize
1170         packets sending and receiving. Defaults to
1171         <literal>no</literal>.</para>
1172         </listitem>
1173       </varlistentry>
1174       <varlistentry>
1175         <term><varname>PacketInfo=</varname></term>
1176         <listitem><para>Takes a boolean. Configures whether
1177         packets should be prepended with four extra bytes (two flag
1178         bytes and two protocol bytes). If disabled, it indicates that
1179         the packets will be pure IP packets. Defaults to
1180         <literal>no</literal>.</para>
1181         </listitem>
1182       </varlistentry>
1183       <varlistentry>
1184         <term><varname>VNetHeader=</varname></term>
1185         <listitem><para>Takes a boolean. Configures
1186         IFF_VNET_HDR flag for a tap device. It allows sending
1187         and receiving larger Generic Segmentation Offload (GSO)
1188         packets. This may increase throughput significantly.
1189         Defaults to
1190         <literal>no</literal>.</para>
1191         </listitem>
1192       </varlistentry>
1193       <varlistentry>
1194         <term><varname>User=</varname></term>
1195         <listitem><para>User to grant access to the
1196         <filename>/dev/net/tun</filename> device.</para>
1197         </listitem>
1198       </varlistentry>
1199       <varlistentry>
1200         <term><varname>Group=</varname></term>
1201         <listitem><para>Group to grant access to the
1202         <filename>/dev/net/tun</filename> device.</para>
1203         </listitem>
1204       </varlistentry>
1205
1206     </variablelist>
1207
1208   </refsect1>
1209
1210   <refsect1>
1211     <title>[Tap] Section Options</title>
1212
1213     <para>The <literal>[Tap]</literal> section only applies for
1214     netdevs of kind <literal>tap</literal>, and accepts the same keys
1215     as the <literal>[Tun]</literal> section.</para>
1216   </refsect1>
1217
1218   <refsect1>
1219     <title>[WireGuard] Section Options</title>
1220
1221     <para>The <literal>[WireGuard]</literal> section accepts the following
1222     keys:</para>
1223
1224     <variablelist class='network-directives'>
1225       <varlistentry>
1226         <term><varname>PrivateKey=</varname></term>
1227         <listitem>
1228           <para>The Base64 encoded private key for the interface. It can be
1229             generated using the <command>wg genkey</command> command
1230             (see <citerefentry project="wireguard"><refentrytitle>wg</refentrytitle><manvolnum>8</manvolnum></citerefentry>).
1231             This option or <varname>PrivateKeyFile=</varname> is mandatory to use WireGuard.
1232             Note that because this information is secret, you may want to set
1233             the permissions of the .netdev file to be owned by <literal>root:systemd-network</literal>
1234             with a <literal>0640</literal> file mode.</para>
1235         </listitem>
1236       </varlistentry>
1237       <varlistentry>
1238         <term><varname>PrivateKeyFile=</varname></term>
1239         <listitem>
1240           <para>Takes a absolute path to a file which contains the Base64 encoded private key for the interface.
1241           If both <varname>PrivateKey=</varname> and <varname>PrivateKeyFile=</varname> are specified, and if
1242           the file specified in <varname>PrivateKeyFile=</varname> contains valid wireguard key, then
1243           the key provided by <varname>PrivateKey=</varname> is ignored.
1244           Note that the file must be readable by the user <literal>systemd-network</literal>, so it
1245           should be, e.g., owned by <literal>root:systemd-network</literal> with a
1246           <literal>0640</literal> file mode.</para>
1247         </listitem>
1248       </varlistentry>
1249       <varlistentry>
1250         <term><varname>ListenPort=</varname></term>
1251         <listitem>
1252           <para>Sets UDP port for listening. Takes either value between 1 and 65535
1253             or <literal>auto</literal>. If <literal>auto</literal> is specified,
1254             the port is automatically generated based on interface name.
1255             Defaults to <literal>auto</literal>.</para>
1256         </listitem>
1257       </varlistentry>
1258       <varlistentry>
1259         <term><varname>FwMark=</varname></term>
1260         <listitem>
1261           <para>Sets a firewall mark on outgoing WireGuard packets from this interface.</para>
1262         </listitem>
1263       </varlistentry>
1264     </variablelist>
1265   </refsect1>
1266
1267   <refsect1>
1268     <title>[WireGuardPeer] Section Options</title>
1269
1270     <para>The <literal>[WireGuardPeer]</literal> section accepts the following
1271     keys:</para>
1272
1273     <variablelist class='network-directives'>
1274       <varlistentry>
1275         <term><varname>PublicKey=</varname></term>
1276         <listitem>
1277           <para>Sets a Base64 encoded public key calculated by <command>wg pubkey</command>
1278             (see <citerefentry project="wireguard"><refentrytitle>wg</refentrytitle><manvolnum>8</manvolnum></citerefentry>)
1279             from a private key, and usually transmitted out of band to the
1280             author of the configuration file. This option is mandatory for this
1281             section.</para>
1282         </listitem>
1283       </varlistentry>
1284       <varlistentry>
1285         <term><varname>PresharedKey=</varname></term>
1286         <listitem>
1287           <para>Optional preshared key for the interface. It can be generated
1288             by the <command>wg genpsk</command> command. This option adds an
1289             additional layer of symmetric-key cryptography to be mixed into the
1290             already existing public-key cryptography, for post-quantum
1291             resistance.
1292             Note that because this information is secret, you may want to set
1293             the permissions of the .netdev file to be owned by <literal>root:systemd-networkd</literal>
1294             with a <literal>0640</literal> file mode.</para>
1295         </listitem>
1296       </varlistentry>
1297       <varlistentry>
1298         <term><varname>AllowedIPs=</varname></term>
1299         <listitem>
1300           <para>Sets a comma-separated list of IP (v4 or v6) addresses with CIDR masks
1301             from which this peer is allowed to send incoming traffic and to
1302             which outgoing traffic for this peer is directed. The catch-all
1303             0.0.0.0/0 may be specified for matching all IPv4 addresses, and
1304             ::/0 may be specified for matching all IPv6 addresses. </para>
1305         </listitem>
1306       </varlistentry>
1307       <varlistentry>
1308         <term><varname>Endpoint=</varname></term>
1309         <listitem>
1310           <para>Sets an endpoint IP address or hostname, followed by a colon, and then
1311             a port number. This endpoint will be updated automatically once to
1312             the most recent source IP address and port of correctly
1313             authenticated packets from the peer at configuration time.</para>
1314         </listitem>
1315       </varlistentry>
1316       <varlistentry>
1317         <term><varname>PersistentKeepalive=</varname></term>
1318         <listitem>
1319           <para>Sets a seconds interval, between 1 and 65535 inclusive, of how often
1320             to send an authenticated empty packet to the peer for the purpose
1321             of keeping a stateful firewall or NAT mapping valid persistently.
1322             For example, if the interface very rarely sends traffic, but it
1323             might at anytime receive traffic from a peer, and it is behind NAT,
1324             the interface might benefit from having a persistent keepalive
1325             interval of 25 seconds. If set to 0 or "off", this option is
1326             disabled. By default or when unspecified, this option is off.
1327             Most users will not need this.</para>
1328         </listitem>
1329       </varlistentry>
1330     </variablelist>
1331   </refsect1>
1332
1333   <refsect1>
1334     <title>[Bond] Section Options</title>
1335
1336     <para>The <literal>[Bond]</literal> section accepts the following
1337     key:</para>
1338
1339     <variablelist class='network-directives'>
1340       <varlistentry>
1341         <term><varname>Mode=</varname></term>
1342         <listitem>
1343           <para>Specifies one of the bonding policies. The default is
1344           <literal>balance-rr</literal> (round robin). Possible values are
1345           <literal>balance-rr</literal>,
1346           <literal>active-backup</literal>,
1347           <literal>balance-xor</literal>,
1348           <literal>broadcast</literal>,
1349           <literal>802.3ad</literal>,
1350           <literal>balance-tlb</literal>, and
1351           <literal>balance-alb</literal>.
1352           </para>
1353         </listitem>
1354       </varlistentry>
1355
1356       <varlistentry>
1357         <term><varname>TransmitHashPolicy=</varname></term>
1358         <listitem>
1359           <para>Selects the transmit hash policy to use for slave
1360           selection in balance-xor, 802.3ad, and tlb modes. Possible
1361           values are
1362           <literal>layer2</literal>,
1363           <literal>layer3+4</literal>,
1364           <literal>layer2+3</literal>,
1365           <literal>encap2+3</literal>, and
1366           <literal>encap3+4</literal>.
1367           </para>
1368         </listitem>
1369       </varlistentry>
1370
1371       <varlistentry>
1372         <term><varname>LACPTransmitRate=</varname></term>
1373         <listitem>
1374           <para>Specifies the rate with which link partner transmits
1375           Link Aggregation Control Protocol Data Unit packets in
1376           802.3ad mode. Possible values are <literal>slow</literal>,
1377           which requests partner to transmit LACPDUs every 30 seconds,
1378           and <literal>fast</literal>, which requests partner to
1379           transmit LACPDUs every second. The default value is
1380           <literal>slow</literal>.</para>
1381         </listitem>
1382       </varlistentry>
1383
1384       <varlistentry>
1385         <term><varname>MIIMonitorSec=</varname></term>
1386         <listitem>
1387           <para>Specifies the frequency that Media Independent
1388           Interface link monitoring will occur. A value of zero
1389           disables MII link monitoring. This value is rounded down to
1390           the nearest millisecond. The default value is 0.</para>
1391         </listitem>
1392       </varlistentry>
1393
1394       <varlistentry>
1395         <term><varname>UpDelaySec=</varname></term>
1396         <listitem>
1397           <para>Specifies the delay before a link is enabled after a
1398           link up status has been detected. This value is rounded down
1399           to a multiple of MIIMonitorSec. The default value is
1400           0.</para>
1401         </listitem>
1402       </varlistentry>
1403
1404       <varlistentry>
1405         <term><varname>DownDelaySec=</varname></term>
1406         <listitem>
1407           <para>Specifies the delay before a link is disabled after a
1408           link down status has been detected. This value is rounded
1409           down to a multiple of MIIMonitorSec. The default value is
1410           0.</para>
1411         </listitem>
1412       </varlistentry>
1413
1414       <varlistentry>
1415         <term><varname>LearnPacketIntervalSec=</varname></term>
1416         <listitem>
1417           <para>Specifies the number of seconds between instances where the bonding
1418           driver sends learning packets to each slave peer switch.
1419           The valid range is 1–0x7fffffff; the default value is 1. This option
1420           has an effect only for the balance-tlb and balance-alb modes.</para>
1421         </listitem>
1422       </varlistentry>
1423
1424       <varlistentry>
1425         <term><varname>AdSelect=</varname></term>
1426         <listitem>
1427           <para>Specifies the 802.3ad aggregation selection logic to use. Possible values are
1428           <literal>stable</literal>,
1429           <literal>bandwidth</literal> and
1430           <literal>count</literal>.
1431           </para>
1432         </listitem>
1433       </varlistentry>
1434
1435       <varlistentry>
1436         <term><varname>AdActorSystemPriority=</varname></term>
1437         <listitem>
1438           <para>Specifies the 802.3ad actor system priority. Ranges [1-65535].</para>
1439         </listitem>
1440       </varlistentry>
1441
1442       <varlistentry>
1443         <term><varname>AdUserPortKey=</varname></term>
1444         <listitem>
1445           <para>Specifies the 802.3ad user defined portion of the port key. Ranges [0-1023].</para>
1446         </listitem>
1447       </varlistentry>
1448
1449       <varlistentry>
1450         <term><varname>AdActorSystem=</varname></term>
1451         <listitem>
1452           <para>Specifies the 802.3ad system mac address. This can not be either NULL or Multicast.</para>
1453         </listitem>
1454       </varlistentry>
1455
1456       <varlistentry>
1457         <term><varname>FailOverMACPolicy=</varname></term>
1458         <listitem>
1459           <para>Specifies whether the active-backup mode should set all slaves to
1460           the same MAC address at the time of enslavement or, when enabled, to perform special handling of the
1461           bond's MAC address in accordance with the selected policy. The default policy is none.
1462           Possible values are
1463           <literal>none</literal>,
1464           <literal>active</literal> and
1465           <literal>follow</literal>.
1466           </para>
1467         </listitem>
1468       </varlistentry>
1469
1470       <varlistentry>
1471         <term><varname>ARPValidate=</varname></term>
1472         <listitem>
1473           <para>Specifies whether or not ARP probes and replies should be
1474           validated in any mode that supports ARP monitoring, or whether
1475           non-ARP traffic should be filtered (disregarded) for link
1476           monitoring purposes. Possible values are
1477           <literal>none</literal>,
1478           <literal>active</literal>,
1479           <literal>backup</literal> and
1480           <literal>all</literal>.
1481           </para>
1482         </listitem>
1483       </varlistentry>
1484
1485       <varlistentry>
1486         <term><varname>ARPIntervalSec=</varname></term>
1487         <listitem>
1488           <para>Specifies the ARP link monitoring frequency in milliseconds.
1489           A value of 0 disables ARP monitoring. The default value is 0.
1490           </para>
1491         </listitem>
1492       </varlistentry>
1493
1494       <varlistentry>
1495         <term><varname>ARPIPTargets=</varname></term>
1496         <listitem>
1497           <para>Specifies the IP addresses to use as ARP monitoring peers when
1498           ARPIntervalSec is greater than 0. These are the targets of the ARP request
1499           sent to determine the health of the link to the targets.
1500           Specify these values in IPv4 dotted decimal format. At least one IP
1501           address must be given for ARP monitoring to function. The
1502           maximum number of targets that can be specified is 16. The
1503           default value is no IP addresses.
1504           </para>
1505         </listitem>
1506       </varlistentry>
1507
1508       <varlistentry>
1509         <term><varname>ARPAllTargets=</varname></term>
1510         <listitem>
1511           <para>Specifies the quantity of ARPIPTargets that must be reachable
1512           in order for the ARP monitor to consider a slave as being up.
1513           This option affects only active-backup mode for slaves with
1514           ARPValidate enabled. Possible values are
1515           <literal>any</literal> and
1516           <literal>all</literal>.
1517           </para>
1518         </listitem>
1519       </varlistentry>
1520
1521       <varlistentry>
1522         <term><varname>PrimaryReselectPolicy=</varname></term>
1523         <listitem>
1524           <para>Specifies the reselection policy for the primary slave.  This
1525           affects how the primary slave is chosen to become the active slave
1526           when failure of the active slave or recovery of the primary slave
1527           occurs. This option is designed to prevent flip-flopping between
1528           the primary slave and other slaves.  Possible values are
1529           <literal>always</literal>,
1530           <literal>better</literal> and
1531           <literal>failure</literal>.
1532           </para>
1533         </listitem>
1534       </varlistentry>
1535
1536       <varlistentry>
1537         <term><varname>ResendIGMP=</varname></term>
1538         <listitem>
1539           <para>Specifies the number of IGMP membership reports to be issued after
1540           a failover event. One membership report is issued immediately after
1541           the failover, subsequent packets are sent in each 200ms interval.
1542           The valid range is 0–255. Defaults to 1. A value of 0
1543           prevents the IGMP membership report from being issued in response
1544           to the failover event.
1545           </para>
1546         </listitem>
1547       </varlistentry>
1548
1549       <varlistentry>
1550         <term><varname>PacketsPerSlave=</varname></term>
1551         <listitem>
1552           <para>Specify the number of packets to transmit through a slave before
1553             moving to the next one. When set to 0, then a slave is chosen at
1554             random. The valid range is 0–65535. Defaults to 1. This option
1555             only has effect when in balance-rr mode.
1556           </para>
1557         </listitem>
1558       </varlistentry>
1559
1560       <varlistentry>
1561         <term><varname>GratuitousARP=</varname></term>
1562         <listitem>
1563           <para>Specify the number of peer notifications (gratuitous ARPs and
1564             unsolicited IPv6 Neighbor Advertisements) to be issued after a
1565             failover event.  As soon as the link is up on the new slave,
1566             a peer notification is sent on the  bonding device and each
1567             VLAN sub-device.  This is repeated at each link monitor interval
1568             (ARPIntervalSec or MIIMonitorSec, whichever is active) if the number is
1569             greater than 1. The valid range is 0–255. The default value is 1.
1570             These options affect only the active-backup mode.
1571           </para>
1572         </listitem>
1573       </varlistentry>
1574
1575       <varlistentry>
1576         <term><varname>AllSlavesActive=</varname></term>
1577         <listitem>
1578           <para>Takes a boolean. Specifies that duplicate frames (received on inactive ports)
1579           should be dropped when false, or delivered when true. Normally, bonding will drop
1580           duplicate frames (received on inactive ports), which is desirable for
1581           most users. But there are some times it is nice to allow duplicate
1582           frames to be delivered. The default value is false (drop duplicate frames
1583           received on inactive ports).
1584           </para>
1585         </listitem>
1586       </varlistentry>
1587
1588       <varlistentry>
1589         <term><varname>DynamicTransmitLoadBalancing=</varname></term>
1590         <listitem>
1591           <para>Takes a boolean. Specifies if dynamic shuffling of flows is enabled. Applies only
1592           for balance-tlb mode. Defaults to unset.
1593           </para>
1594         </listitem>
1595       </varlistentry>
1596
1597       <varlistentry>
1598         <term><varname>MinLinks=</varname></term>
1599         <listitem>
1600           <para>Specifies the minimum number of links that must be active before
1601           asserting carrier. The default value is 0.
1602           </para>
1603         </listitem>
1604       </varlistentry>
1605     </variablelist>
1606
1607     <para>For more detail information see
1608     <ulink url="https://www.kernel.org/doc/Documentation/networking/bonding.txt">
1609     Linux Ethernet Bonding Driver HOWTO</ulink></para>
1610
1611   </refsect1>
1612
1613   <refsect1>
1614     <title>Examples</title>
1615     <example>
1616       <title>/etc/systemd/network/25-bridge.netdev</title>
1617
1618       <programlisting>[NetDev]
1619 Name=bridge0
1620 Kind=bridge</programlisting>
1621     </example>
1622
1623     <example>
1624       <title>/etc/systemd/network/25-vlan1.netdev</title>
1625
1626       <programlisting>[Match]
1627 Virtualization=no
1628
1629 [NetDev]
1630 Name=vlan1
1631 Kind=vlan
1632
1633 [VLAN]
1634 Id=1</programlisting>
1635     </example>
1636     <example>
1637       <title>/etc/systemd/network/25-ipip.netdev</title>
1638       <programlisting>[NetDev]
1639 Name=ipip-tun
1640 Kind=ipip
1641 MTUBytes=1480
1642
1643 [Tunnel]
1644 Local=192.168.223.238
1645 Remote=192.169.224.239
1646 TTL=64</programlisting>
1647     </example>
1648     <example>
1649       <title>/etc/systemd/network/1-fou-tunnel.netdev</title>
1650       <programlisting>[NetDev]
1651 Name=fou-tun
1652 Kind=fou
1653
1654 [FooOverUDP]
1655 Port=5555
1656 Protocol=4
1657       </programlisting>
1658     </example>
1659     <example>
1660       <title>/etc/systemd/network/25-fou-ipip.netdev</title>
1661       <programlisting>[NetDev]
1662 Name=ipip-tun
1663 Kind=ipip
1664
1665 [Tunnel]
1666 Independent=yes
1667 Local=10.65.208.212
1668 Remote=10.65.208.211
1669 FooOverUDP=yes
1670 FOUDestinationPort=5555
1671       </programlisting>
1672     </example>
1673     <example>
1674       <title>/etc/systemd/network/25-tap.netdev</title>
1675       <programlisting>[NetDev]
1676 Name=tap-test
1677 Kind=tap
1678
1679 [Tap]
1680 MultiQueue=yes
1681 PacketInfo=yes</programlisting> </example>
1682
1683     <example>
1684       <title>/etc/systemd/network/25-sit.netdev</title>
1685       <programlisting>[NetDev]
1686 Name=sit-tun
1687 Kind=sit
1688 MTUBytes=1480
1689
1690 [Tunnel]
1691 Local=10.65.223.238
1692 Remote=10.65.223.239</programlisting>
1693     </example>
1694
1695     <example>
1696       <title>/etc/systemd/network/25-6rd.netdev</title>
1697       <programlisting>[NetDev]
1698 Name=6rd-tun
1699 Kind=sit
1700 MTUBytes=1480
1701
1702 [Tunnel]
1703 Local=10.65.223.238
1704 IPv6RapidDeploymentPrefix=2602::/24</programlisting>
1705     </example>
1706
1707     <example>
1708       <title>/etc/systemd/network/25-gre.netdev</title>
1709       <programlisting>[NetDev]
1710 Name=gre-tun
1711 Kind=gre
1712 MTUBytes=1480
1713
1714 [Tunnel]
1715 Local=10.65.223.238
1716 Remote=10.65.223.239</programlisting>
1717     </example>
1718
1719     <example>
1720       <title>/etc/systemd/network/25-vti.netdev</title>
1721
1722       <programlisting>[NetDev]
1723 Name=vti-tun
1724 Kind=vti
1725 MTUBytes=1480
1726
1727 [Tunnel]
1728 Local=10.65.223.238
1729 Remote=10.65.223.239</programlisting>
1730     </example>
1731
1732     <example>
1733       <title>/etc/systemd/network/25-veth.netdev</title>
1734       <programlisting>[NetDev]
1735 Name=veth-test
1736 Kind=veth
1737
1738 [Peer]
1739 Name=veth-peer</programlisting>
1740     </example>
1741
1742     <example>
1743       <title>/etc/systemd/network/25-bond.netdev</title>
1744       <programlisting>[NetDev]
1745 Name=bond1
1746 Kind=bond
1747
1748 [Bond]
1749 Mode=802.3ad
1750 TransmitHashPolicy=layer3+4
1751 MIIMonitorSec=1s
1752 LACPTransmitRate=fast
1753 </programlisting>
1754     </example>
1755
1756     <example>
1757       <title>/etc/systemd/network/25-dummy.netdev</title>
1758       <programlisting>[NetDev]
1759 Name=dummy-test
1760 Kind=dummy
1761 MACAddress=12:34:56:78:9a:bc</programlisting>
1762     </example>
1763     <example>
1764       <title>/etc/systemd/network/25-vrf.netdev</title>
1765       <para>Create a VRF interface with table 42.</para>
1766       <programlisting>[NetDev]
1767 Name=vrf-test
1768 Kind=vrf
1769
1770 [VRF]
1771 Table=42</programlisting>
1772     </example>
1773
1774     <example>
1775       <title>/etc/systemd/network/25-macvtap.netdev</title>
1776       <para>Create a MacVTap device.</para>
1777       <programlisting>[NetDev]
1778 Name=macvtap-test
1779 Kind=macvtap
1780       </programlisting>
1781     </example>
1782     <example>
1783       <title>/etc/systemd/network/25-wireguard.netdev</title>
1784       <programlisting>[NetDev]
1785 Name=wg0
1786 Kind=wireguard
1787
1788 [WireGuard]
1789 PrivateKey=EEGlnEPYJV//kbvvIqxKkQwOiS+UENyPncC4bF46ong=
1790 ListenPort=51820
1791
1792 [WireGuardPeer]
1793 PublicKey=RDf+LSpeEre7YEIKaxg+wbpsNV7du+ktR99uBEtIiCA=
1794 AllowedIPs=fd31:bf08:57cb::/48,192.168.26.0/24
1795 Endpoint=wireguard.example.com:51820</programlisting>
1796     </example>
1797   </refsect1>
1798   <refsect1>
1799     <title>See Also</title>
1800     <para>
1801       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1802       <citerefentry><refentrytitle>systemd-networkd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
1803       <citerefentry><refentrytitle>systemd.link</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1804       <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>
1805     </para>
1806   </refsect1>
1807
1808 </refentry>