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