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. This takes effects only for IPIP, SIT, GRE, and GRETAP tunnels.
1012           For more detail information see
1013           <ulink url="https://lwn.net/Articles/614348">Foo over UDP</ulink></para>
1014         </listitem>
1015       </varlistentry>
1016       <varlistentry>
1017         <term><varname>FOUDestinationPort=</varname></term>
1018         <listitem>
1019           <para>This setting specifies the UDP destination port for encapsulation.
1020           This field is mandatory when <varname>FooOverUDP=yes</varname>, and is not set by default.</para>
1021         </listitem>
1022       </varlistentry>
1023       <varlistentry>
1024         <term><varname>FOUSourcePort=</varname></term>
1025         <listitem>
1026           <para>This setting specifies the UDP source port for encapsulation. Defaults to <constant>0</constant>
1027           — that is, the source port for packets is left to the network stack to decide.</para>
1028         </listitem>
1029       </varlistentry>
1030       <varlistentry>
1031         <term><varname>Encapsulation=</varname></term>
1032         <listitem>
1033           <para>Accepts the same key as in the <literal>[FooOverUDP]</literal> section.</para>
1034         </listitem>
1035       </varlistentry>
1036       <varlistentry>
1037         <term><varname>IPv6RapidDeploymentPrefix=</varname></term>
1038         <listitem>
1039           <para>Reconfigure the tunnel for <ulink url="https://tools.ietf.org/html/rfc5569">IPv6 Rapid
1040           Deployment</ulink>, also known as 6rd. The value is an ISP-specific IPv6 prefix with a non-zero length. Only
1041           applicable to SIT tunnels.</para>
1042         </listitem>
1043       </varlistentry>
1044       <varlistentry>
1045         <term><varname>ISATAP=</varname></term>
1046         <listitem>
1047           <para>Takes a boolean. If set, configures the tunnel as Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) tunnel.
1048           Only applicable to SIT tunnels. When unset, the kernel's default will be used.</para>
1049         </listitem>
1050       </varlistentry>
1051       <varlistentry>
1052         <term><varname>SerializeTunneledPackets=</varname></term>
1053         <listitem>
1054           <para>Takes a boolean. If set to yes, then packets are serialized. Only applies for GRE,
1055           GRETAP, and ERSPAN tunnels. When unset, the kernel's default will be used.
1056           </para>
1057         </listitem>
1058       </varlistentry>
1059       <varlistentry>
1060         <term><varname>ERSPANIndex=</varname></term>
1061         <listitem>
1062           <para>Specifies the ERSPAN index field for the interface, an integer in the range 1-1048575 associated with
1063           the ERSPAN traffic's source port and direction. This field is mandatory.
1064           </para>
1065         </listitem>
1066       </varlistentry>
1067     </variablelist>
1068   </refsect1>
1069
1070   <refsect1>
1071     <title>[FooOverUDP] Section Options</title>
1072
1073     <para>The <literal>[FooOverUDP]</literal> section only applies for
1074     netdevs of kind <literal>fou</literal> and accepts the
1075     following keys:</para>
1076
1077     <variablelist class='network-directives'>
1078       <varlistentry>
1079         <term><varname>Encapsulation=</varname></term>
1080         <listitem>
1081           <para>Specifies the encapsulation mechanism used to store networking packets of various protocols inside the UDP packets. Supports the following values:
1082
1083           <literal>FooOverUDP</literal> provides the simplest no frills model of UDP encapsulation, it simply encapsulates
1084           packets directly in the UDP payload.
1085           <literal>GenericUDPEncapsulation</literal> is a generic and extensible encapsulation, it allows encapsulation of packets for any IP
1086           protocol and optional data as part of the encapsulation.
1087           For more detailed information see <ulink url="https://lwn.net/Articles/615044">Generic UDP Encapsulation</ulink>.
1088           Defaults to <literal>FooOverUDP</literal>.
1089           </para>
1090         </listitem>
1091       </varlistentry>
1092       <varlistentry>
1093         <term><varname>Port=</varname></term>
1094         <listitem>
1095           <para>Specifies the port number, where the IP encapsulation packets will arrive. Please take note that the packets
1096           will arrive with the encapsulation will be removed. Then they will be manually fed back into the network stack, and sent ahead
1097           for delivery to the real destination. This option is mandatory.</para>
1098         </listitem>
1099         </varlistentry>
1100       <varlistentry>
1101         <term><varname>Protocol=</varname></term>
1102         <listitem>
1103           <para>The <varname>Protocol=</varname> specifies the protocol number of the packets arriving
1104           at the UDP port. When <varname>Encapsulation=FooOverUDP</varname>, this field is mandatory
1105           and is not set by default. Takes an IP protocol name such as <literal>gre</literal> or
1106           <literal>ipip</literal>, or an integer within the range 1-255. When
1107           <varname>Encapsulation=GenericUDPEncapsulation</varname>, this must not be specified.</para>
1108         </listitem>
1109       </varlistentry>
1110     </variablelist>
1111   </refsect1>
1112   <refsect1>
1113     <title>[Peer] Section Options</title>
1114
1115       <para>The <literal>[Peer]</literal> section only applies for
1116       netdevs of kind <literal>veth</literal> and accepts the
1117       following keys:</para>
1118
1119       <variablelist class='network-directives'>
1120         <varlistentry>
1121           <term><varname>Name=</varname></term>
1122           <listitem>
1123             <para>The interface name used when creating the netdev.
1124             This option is compulsory.</para>
1125           </listitem>
1126         </varlistentry>
1127         <varlistentry>
1128           <term><varname>MACAddress=</varname></term>
1129           <listitem>
1130             <para>The peer MACAddress, if not set, it is generated in
1131             the same way as the MAC address of the main
1132             interface.</para>
1133           </listitem>
1134         </varlistentry>
1135       </variablelist>
1136   </refsect1>
1137   <refsect1>
1138   <title>[VXCAN] Section Options</title>
1139       <para>The <literal>[VXCAN]</literal> section only applies for
1140       netdevs of kind <literal>vxcan</literal> and accepts the
1141       following key:</para>
1142
1143       <variablelist class='network-directives'>
1144         <varlistentry>
1145           <term><varname>Peer=</varname></term>
1146           <listitem>
1147             <para>The peer interface name used when creating the netdev.
1148             This option is compulsory.</para>
1149           </listitem>
1150         </varlistentry>
1151       </variablelist>
1152   </refsect1>
1153   <refsect1>
1154     <title>[Tun] Section Options</title>
1155
1156     <para>The <literal>[Tun]</literal> section only applies for
1157     netdevs of kind <literal>tun</literal>, and accepts the following
1158     keys:</para>
1159
1160     <variablelist class='network-directives'>
1161       <varlistentry>
1162         <term><varname>OneQueue=</varname></term>
1163         <listitem><para>Takes a boolean. Configures whether
1164         all packets are queued at the device (enabled), or a fixed
1165         number of packets are queued at the device and the rest at the
1166         <literal>qdisc</literal>. Defaults to
1167         <literal>no</literal>.</para>
1168         </listitem>
1169       </varlistentry>
1170       <varlistentry>
1171         <term><varname>MultiQueue=</varname></term>
1172         <listitem><para>Takes a boolean. Configures whether
1173         to use multiple file descriptors (queues) to parallelize
1174         packets sending and receiving. Defaults to
1175         <literal>no</literal>.</para>
1176         </listitem>
1177       </varlistentry>
1178       <varlistentry>
1179         <term><varname>PacketInfo=</varname></term>
1180         <listitem><para>Takes a boolean. Configures whether
1181         packets should be prepended with four extra bytes (two flag
1182         bytes and two protocol bytes). If disabled, it indicates that
1183         the packets will be pure IP packets. Defaults to
1184         <literal>no</literal>.</para>
1185         </listitem>
1186       </varlistentry>
1187       <varlistentry>
1188         <term><varname>VNetHeader=</varname></term>
1189         <listitem><para>Takes a boolean. Configures
1190         IFF_VNET_HDR flag for a tap device. It allows sending
1191         and receiving larger Generic Segmentation Offload (GSO)
1192         packets. This may increase throughput significantly.
1193         Defaults to
1194         <literal>no</literal>.</para>
1195         </listitem>
1196       </varlistentry>
1197       <varlistentry>
1198         <term><varname>User=</varname></term>
1199         <listitem><para>User to grant access to the
1200         <filename>/dev/net/tun</filename> device.</para>
1201         </listitem>
1202       </varlistentry>
1203       <varlistentry>
1204         <term><varname>Group=</varname></term>
1205         <listitem><para>Group to grant access to the
1206         <filename>/dev/net/tun</filename> device.</para>
1207         </listitem>
1208       </varlistentry>
1209
1210     </variablelist>
1211
1212   </refsect1>
1213
1214   <refsect1>
1215     <title>[Tap] Section Options</title>
1216
1217     <para>The <literal>[Tap]</literal> section only applies for
1218     netdevs of kind <literal>tap</literal>, and accepts the same keys
1219     as the <literal>[Tun]</literal> section.</para>
1220   </refsect1>
1221
1222   <refsect1>
1223     <title>[WireGuard] Section Options</title>
1224
1225     <para>The <literal>[WireGuard]</literal> section accepts the following
1226     keys:</para>
1227
1228     <variablelist class='network-directives'>
1229       <varlistentry>
1230         <term><varname>PrivateKey=</varname></term>
1231         <listitem>
1232           <para>The Base64 encoded private key for the interface. It can be
1233             generated using the <command>wg genkey</command> command
1234             (see <citerefentry project="wireguard"><refentrytitle>wg</refentrytitle><manvolnum>8</manvolnum></citerefentry>).
1235             This option or <varname>PrivateKeyFile=</varname> is mandatory to use WireGuard.
1236             Note that because this information is secret, you may want to set
1237             the permissions of the .netdev file to be owned by <literal>root:systemd-network</literal>
1238             with a <literal>0640</literal> file mode.</para>
1239         </listitem>
1240       </varlistentry>
1241       <varlistentry>
1242         <term><varname>PrivateKeyFile=</varname></term>
1243         <listitem>
1244           <para>Takes an absolute path to a file which contains the Base64 encoded private key for the interface.
1245           When this option is specified, then <varname>PrivateKey=</varname> is ignored.
1246           Note that the file must be readable by the user <literal>systemd-network</literal>, so it
1247           should be, e.g., owned by <literal>root:systemd-network</literal> with a
1248           <literal>0640</literal> file mode.</para>
1249         </listitem>
1250       </varlistentry>
1251       <varlistentry>
1252         <term><varname>ListenPort=</varname></term>
1253         <listitem>
1254           <para>Sets UDP port for listening. Takes either value between 1 and 65535
1255             or <literal>auto</literal>. If <literal>auto</literal> is specified,
1256             the port is automatically generated based on interface name.
1257             Defaults to <literal>auto</literal>.</para>
1258         </listitem>
1259       </varlistentry>
1260       <varlistentry>
1261         <term><varname>FwMark=</varname></term>
1262         <listitem>
1263           <para>Sets a firewall mark on outgoing WireGuard packets from this interface.</para>
1264         </listitem>
1265       </varlistentry>
1266     </variablelist>
1267   </refsect1>
1268
1269   <refsect1>
1270     <title>[WireGuardPeer] Section Options</title>
1271
1272     <para>The <literal>[WireGuardPeer]</literal> section accepts the following
1273     keys:</para>
1274
1275     <variablelist class='network-directives'>
1276       <varlistentry>
1277         <term><varname>PublicKey=</varname></term>
1278         <listitem>
1279           <para>Sets a Base64 encoded public key calculated by <command>wg pubkey</command>
1280             (see <citerefentry project="wireguard"><refentrytitle>wg</refentrytitle><manvolnum>8</manvolnum></citerefentry>)
1281             from a private key, and usually transmitted out of band to the
1282             author of the configuration file. This option is mandatory for this
1283             section.</para>
1284         </listitem>
1285       </varlistentry>
1286       <varlistentry>
1287         <term><varname>PresharedKey=</varname></term>
1288         <listitem>
1289           <para>Optional preshared key for the interface. It can be generated
1290             by the <command>wg genpsk</command> command. This option adds an
1291             additional layer of symmetric-key cryptography to be mixed into the
1292             already existing public-key cryptography, for post-quantum
1293             resistance.
1294             Note that because this information is secret, you may want to set
1295             the permissions of the .netdev file to be owned by <literal>root:systemd-networkd</literal>
1296             with a <literal>0640</literal> file mode.</para>
1297         </listitem>
1298       </varlistentry>
1299       <varlistentry>
1300         <term><varname>PresharedKeyFile=</varname></term>
1301         <listitem>
1302           <para>Takes an absolute path to a file which contains the Base64 encoded preshared key for the
1303           peer. When this option is specified, then <varname>PresharedKey=</varname> is ignored.
1304           Note that the file must be readable by the user <literal>systemd-network</literal>, so it
1305           should be, e.g., owned by <literal>root:systemd-network</literal> with a
1306           <literal>0640</literal> file mode.</para>
1307         </listitem>
1308       </varlistentry>
1309       <varlistentry>
1310         <term><varname>AllowedIPs=</varname></term>
1311         <listitem>
1312           <para>Sets a comma-separated list of IP (v4 or v6) addresses with CIDR masks
1313             from which this peer is allowed to send incoming traffic and to
1314             which outgoing traffic for this peer is directed. The catch-all
1315             0.0.0.0/0 may be specified for matching all IPv4 addresses, and
1316             ::/0 may be specified for matching all IPv6 addresses. </para>
1317         </listitem>
1318       </varlistentry>
1319       <varlistentry>
1320         <term><varname>Endpoint=</varname></term>
1321         <listitem>
1322           <para>Sets an endpoint IP address or hostname, followed by a colon, and then
1323             a port number. This endpoint will be updated automatically once to
1324             the most recent source IP address and port of correctly
1325             authenticated packets from the peer at configuration time.</para>
1326         </listitem>
1327       </varlistentry>
1328       <varlistentry>
1329         <term><varname>PersistentKeepalive=</varname></term>
1330         <listitem>
1331           <para>Sets a seconds interval, between 1 and 65535 inclusive, of how often
1332             to send an authenticated empty packet to the peer for the purpose
1333             of keeping a stateful firewall or NAT mapping valid persistently.
1334             For example, if the interface very rarely sends traffic, but it
1335             might at anytime receive traffic from a peer, and it is behind NAT,
1336             the interface might benefit from having a persistent keepalive
1337             interval of 25 seconds. If set to 0 or "off", this option is
1338             disabled. By default or when unspecified, this option is off.
1339             Most users will not need this.</para>
1340         </listitem>
1341       </varlistentry>
1342     </variablelist>
1343   </refsect1>
1344
1345   <refsect1>
1346     <title>[Bond] Section Options</title>
1347
1348     <para>The <literal>[Bond]</literal> section accepts the following
1349     key:</para>
1350
1351     <variablelist class='network-directives'>
1352       <varlistentry>
1353         <term><varname>Mode=</varname></term>
1354         <listitem>
1355           <para>Specifies one of the bonding policies. The default is
1356           <literal>balance-rr</literal> (round robin). Possible values are
1357           <literal>balance-rr</literal>,
1358           <literal>active-backup</literal>,
1359           <literal>balance-xor</literal>,
1360           <literal>broadcast</literal>,
1361           <literal>802.3ad</literal>,
1362           <literal>balance-tlb</literal>, and
1363           <literal>balance-alb</literal>.
1364           </para>
1365         </listitem>
1366       </varlistentry>
1367
1368       <varlistentry>
1369         <term><varname>TransmitHashPolicy=</varname></term>
1370         <listitem>
1371           <para>Selects the transmit hash policy to use for slave
1372           selection in balance-xor, 802.3ad, and tlb modes. Possible
1373           values are
1374           <literal>layer2</literal>,
1375           <literal>layer3+4</literal>,
1376           <literal>layer2+3</literal>,
1377           <literal>encap2+3</literal>, and
1378           <literal>encap3+4</literal>.
1379           </para>
1380         </listitem>
1381       </varlistentry>
1382
1383       <varlistentry>
1384         <term><varname>LACPTransmitRate=</varname></term>
1385         <listitem>
1386           <para>Specifies the rate with which link partner transmits
1387           Link Aggregation Control Protocol Data Unit packets in
1388           802.3ad mode. Possible values are <literal>slow</literal>,
1389           which requests partner to transmit LACPDUs every 30 seconds,
1390           and <literal>fast</literal>, which requests partner to
1391           transmit LACPDUs every second. The default value is
1392           <literal>slow</literal>.</para>
1393         </listitem>
1394       </varlistentry>
1395
1396       <varlistentry>
1397         <term><varname>MIIMonitorSec=</varname></term>
1398         <listitem>
1399           <para>Specifies the frequency that Media Independent
1400           Interface link monitoring will occur. A value of zero
1401           disables MII link monitoring. This value is rounded down to
1402           the nearest millisecond. The default value is 0.</para>
1403         </listitem>
1404       </varlistentry>
1405
1406       <varlistentry>
1407         <term><varname>UpDelaySec=</varname></term>
1408         <listitem>
1409           <para>Specifies the delay before a link is enabled after a
1410           link up status has been detected. This value is rounded down
1411           to a multiple of MIIMonitorSec. The default value is
1412           0.</para>
1413         </listitem>
1414       </varlistentry>
1415
1416       <varlistentry>
1417         <term><varname>DownDelaySec=</varname></term>
1418         <listitem>
1419           <para>Specifies the delay before a link is disabled after a
1420           link down status has been detected. This value is rounded
1421           down to a multiple of MIIMonitorSec. The default value is
1422           0.</para>
1423         </listitem>
1424       </varlistentry>
1425
1426       <varlistentry>
1427         <term><varname>LearnPacketIntervalSec=</varname></term>
1428         <listitem>
1429           <para>Specifies the number of seconds between instances where the bonding
1430           driver sends learning packets to each slave peer switch.
1431           The valid range is 1–0x7fffffff; the default value is 1. This option
1432           has an effect only for the balance-tlb and balance-alb modes.</para>
1433         </listitem>
1434       </varlistentry>
1435
1436       <varlistentry>
1437         <term><varname>AdSelect=</varname></term>
1438         <listitem>
1439           <para>Specifies the 802.3ad aggregation selection logic to use. Possible values are
1440           <literal>stable</literal>,
1441           <literal>bandwidth</literal> and
1442           <literal>count</literal>.
1443           </para>
1444         </listitem>
1445       </varlistentry>
1446
1447       <varlistentry>
1448         <term><varname>AdActorSystemPriority=</varname></term>
1449         <listitem>
1450           <para>Specifies the 802.3ad actor system priority. Ranges [1-65535].</para>
1451         </listitem>
1452       </varlistentry>
1453
1454       <varlistentry>
1455         <term><varname>AdUserPortKey=</varname></term>
1456         <listitem>
1457           <para>Specifies the 802.3ad user defined portion of the port key. Ranges [0-1023].</para>
1458         </listitem>
1459       </varlistentry>
1460
1461       <varlistentry>
1462         <term><varname>AdActorSystem=</varname></term>
1463         <listitem>
1464           <para>Specifies the 802.3ad system mac address. This can not be either NULL or Multicast.</para>
1465         </listitem>
1466       </varlistentry>
1467
1468       <varlistentry>
1469         <term><varname>FailOverMACPolicy=</varname></term>
1470         <listitem>
1471           <para>Specifies whether the active-backup mode should set all slaves to
1472           the same MAC address at the time of enslavement or, when enabled, to perform special handling of the
1473           bond's MAC address in accordance with the selected policy. The default policy is none.
1474           Possible values are
1475           <literal>none</literal>,
1476           <literal>active</literal> and
1477           <literal>follow</literal>.
1478           </para>
1479         </listitem>
1480       </varlistentry>
1481
1482       <varlistentry>
1483         <term><varname>ARPValidate=</varname></term>
1484         <listitem>
1485           <para>Specifies whether or not ARP probes and replies should be
1486           validated in any mode that supports ARP monitoring, or whether
1487           non-ARP traffic should be filtered (disregarded) for link
1488           monitoring purposes. Possible values are
1489           <literal>none</literal>,
1490           <literal>active</literal>,
1491           <literal>backup</literal> and
1492           <literal>all</literal>.
1493           </para>
1494         </listitem>
1495       </varlistentry>
1496
1497       <varlistentry>
1498         <term><varname>ARPIntervalSec=</varname></term>
1499         <listitem>
1500           <para>Specifies the ARP link monitoring frequency in milliseconds.
1501           A value of 0 disables ARP monitoring. The default value is 0.
1502           </para>
1503         </listitem>
1504       </varlistentry>
1505
1506       <varlistentry>
1507         <term><varname>ARPIPTargets=</varname></term>
1508         <listitem>
1509           <para>Specifies the IP addresses to use as ARP monitoring peers when
1510           ARPIntervalSec is greater than 0. These are the targets of the ARP request
1511           sent to determine the health of the link to the targets.
1512           Specify these values in IPv4 dotted decimal format. At least one IP
1513           address must be given for ARP monitoring to function. The
1514           maximum number of targets that can be specified is 16. The
1515           default value is no IP addresses.
1516           </para>
1517         </listitem>
1518       </varlistentry>
1519
1520       <varlistentry>
1521         <term><varname>ARPAllTargets=</varname></term>
1522         <listitem>
1523           <para>Specifies the quantity of ARPIPTargets that must be reachable
1524           in order for the ARP monitor to consider a slave as being up.
1525           This option affects only active-backup mode for slaves with
1526           ARPValidate enabled. Possible values are
1527           <literal>any</literal> and
1528           <literal>all</literal>.
1529           </para>
1530         </listitem>
1531       </varlistentry>
1532
1533       <varlistentry>
1534         <term><varname>PrimaryReselectPolicy=</varname></term>
1535         <listitem>
1536           <para>Specifies the reselection policy for the primary slave.  This
1537           affects how the primary slave is chosen to become the active slave
1538           when failure of the active slave or recovery of the primary slave
1539           occurs. This option is designed to prevent flip-flopping between
1540           the primary slave and other slaves.  Possible values are
1541           <literal>always</literal>,
1542           <literal>better</literal> and
1543           <literal>failure</literal>.
1544           </para>
1545         </listitem>
1546       </varlistentry>
1547
1548       <varlistentry>
1549         <term><varname>ResendIGMP=</varname></term>
1550         <listitem>
1551           <para>Specifies the number of IGMP membership reports to be issued after
1552           a failover event. One membership report is issued immediately after
1553           the failover, subsequent packets are sent in each 200ms interval.
1554           The valid range is 0–255. Defaults to 1. A value of 0
1555           prevents the IGMP membership report from being issued in response
1556           to the failover event.
1557           </para>
1558         </listitem>
1559       </varlistentry>
1560
1561       <varlistentry>
1562         <term><varname>PacketsPerSlave=</varname></term>
1563         <listitem>
1564           <para>Specify the number of packets to transmit through a slave before
1565             moving to the next one. When set to 0, then a slave is chosen at
1566             random. The valid range is 0–65535. Defaults to 1. This option
1567             only has effect when in balance-rr mode.
1568           </para>
1569         </listitem>
1570       </varlistentry>
1571
1572       <varlistentry>
1573         <term><varname>GratuitousARP=</varname></term>
1574         <listitem>
1575           <para>Specify the number of peer notifications (gratuitous ARPs and
1576             unsolicited IPv6 Neighbor Advertisements) to be issued after a
1577             failover event.  As soon as the link is up on the new slave,
1578             a peer notification is sent on the  bonding device and each
1579             VLAN sub-device.  This is repeated at each link monitor interval
1580             (ARPIntervalSec or MIIMonitorSec, whichever is active) if the number is
1581             greater than 1. The valid range is 0–255. The default value is 1.
1582             These options affect only the active-backup mode.
1583           </para>
1584         </listitem>
1585       </varlistentry>
1586
1587       <varlistentry>
1588         <term><varname>AllSlavesActive=</varname></term>
1589         <listitem>
1590           <para>Takes a boolean. Specifies that duplicate frames (received on inactive ports)
1591           should be dropped when false, or delivered when true. Normally, bonding will drop
1592           duplicate frames (received on inactive ports), which is desirable for
1593           most users. But there are some times it is nice to allow duplicate
1594           frames to be delivered. The default value is false (drop duplicate frames
1595           received on inactive ports).
1596           </para>
1597         </listitem>
1598       </varlistentry>
1599
1600       <varlistentry>
1601         <term><varname>DynamicTransmitLoadBalancing=</varname></term>
1602         <listitem>
1603           <para>Takes a boolean. Specifies if dynamic shuffling of flows is enabled. Applies only
1604           for balance-tlb mode. Defaults to unset.
1605           </para>
1606         </listitem>
1607       </varlistentry>
1608
1609       <varlistentry>
1610         <term><varname>MinLinks=</varname></term>
1611         <listitem>
1612           <para>Specifies the minimum number of links that must be active before
1613           asserting carrier. The default value is 0.
1614           </para>
1615         </listitem>
1616       </varlistentry>
1617     </variablelist>
1618
1619     <para>For more detail information see
1620     <ulink url="https://www.kernel.org/doc/Documentation/networking/bonding.txt">
1621     Linux Ethernet Bonding Driver HOWTO</ulink></para>
1622
1623   </refsect1>
1624
1625   <refsect1>
1626     <title>Examples</title>
1627     <example>
1628       <title>/etc/systemd/network/25-bridge.netdev</title>
1629
1630       <programlisting>[NetDev]
1631 Name=bridge0
1632 Kind=bridge</programlisting>
1633     </example>
1634
1635     <example>
1636       <title>/etc/systemd/network/25-vlan1.netdev</title>
1637
1638       <programlisting>[Match]
1639 Virtualization=no
1640
1641 [NetDev]
1642 Name=vlan1
1643 Kind=vlan
1644
1645 [VLAN]
1646 Id=1</programlisting>
1647     </example>
1648     <example>
1649       <title>/etc/systemd/network/25-ipip.netdev</title>
1650       <programlisting>[NetDev]
1651 Name=ipip-tun
1652 Kind=ipip
1653 MTUBytes=1480
1654
1655 [Tunnel]
1656 Local=192.168.223.238
1657 Remote=192.169.224.239
1658 TTL=64</programlisting>
1659     </example>
1660     <example>
1661       <title>/etc/systemd/network/1-fou-tunnel.netdev</title>
1662       <programlisting>[NetDev]
1663 Name=fou-tun
1664 Kind=fou
1665
1666 [FooOverUDP]
1667 Port=5555
1668 Protocol=4
1669       </programlisting>
1670     </example>
1671     <example>
1672       <title>/etc/systemd/network/25-fou-ipip.netdev</title>
1673       <programlisting>[NetDev]
1674 Name=ipip-tun
1675 Kind=ipip
1676
1677 [Tunnel]
1678 Independent=yes
1679 Local=10.65.208.212
1680 Remote=10.65.208.211
1681 FooOverUDP=yes
1682 FOUDestinationPort=5555
1683       </programlisting>
1684     </example>
1685     <example>
1686       <title>/etc/systemd/network/25-tap.netdev</title>
1687       <programlisting>[NetDev]
1688 Name=tap-test
1689 Kind=tap
1690
1691 [Tap]
1692 MultiQueue=yes
1693 PacketInfo=yes</programlisting> </example>
1694
1695     <example>
1696       <title>/etc/systemd/network/25-sit.netdev</title>
1697       <programlisting>[NetDev]
1698 Name=sit-tun
1699 Kind=sit
1700 MTUBytes=1480
1701
1702 [Tunnel]
1703 Local=10.65.223.238
1704 Remote=10.65.223.239</programlisting>
1705     </example>
1706
1707     <example>
1708       <title>/etc/systemd/network/25-6rd.netdev</title>
1709       <programlisting>[NetDev]
1710 Name=6rd-tun
1711 Kind=sit
1712 MTUBytes=1480
1713
1714 [Tunnel]
1715 Local=10.65.223.238
1716 IPv6RapidDeploymentPrefix=2602::/24</programlisting>
1717     </example>
1718
1719     <example>
1720       <title>/etc/systemd/network/25-gre.netdev</title>
1721       <programlisting>[NetDev]
1722 Name=gre-tun
1723 Kind=gre
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-vti.netdev</title>
1733
1734       <programlisting>[NetDev]
1735 Name=vti-tun
1736 Kind=vti
1737 MTUBytes=1480
1738
1739 [Tunnel]
1740 Local=10.65.223.238
1741 Remote=10.65.223.239</programlisting>
1742     </example>
1743
1744     <example>
1745       <title>/etc/systemd/network/25-veth.netdev</title>
1746       <programlisting>[NetDev]
1747 Name=veth-test
1748 Kind=veth
1749
1750 [Peer]
1751 Name=veth-peer</programlisting>
1752     </example>
1753
1754     <example>
1755       <title>/etc/systemd/network/25-bond.netdev</title>
1756       <programlisting>[NetDev]
1757 Name=bond1
1758 Kind=bond
1759
1760 [Bond]
1761 Mode=802.3ad
1762 TransmitHashPolicy=layer3+4
1763 MIIMonitorSec=1s
1764 LACPTransmitRate=fast
1765 </programlisting>
1766     </example>
1767
1768     <example>
1769       <title>/etc/systemd/network/25-dummy.netdev</title>
1770       <programlisting>[NetDev]
1771 Name=dummy-test
1772 Kind=dummy
1773 MACAddress=12:34:56:78:9a:bc</programlisting>
1774     </example>
1775     <example>
1776       <title>/etc/systemd/network/25-vrf.netdev</title>
1777       <para>Create a VRF interface with table 42.</para>
1778       <programlisting>[NetDev]
1779 Name=vrf-test
1780 Kind=vrf
1781
1782 [VRF]
1783 Table=42</programlisting>
1784     </example>
1785
1786     <example>
1787       <title>/etc/systemd/network/25-macvtap.netdev</title>
1788       <para>Create a MacVTap device.</para>
1789       <programlisting>[NetDev]
1790 Name=macvtap-test
1791 Kind=macvtap
1792       </programlisting>
1793     </example>
1794     <example>
1795       <title>/etc/systemd/network/25-wireguard.netdev</title>
1796       <programlisting>[NetDev]
1797 Name=wg0
1798 Kind=wireguard
1799
1800 [WireGuard]
1801 PrivateKey=EEGlnEPYJV//kbvvIqxKkQwOiS+UENyPncC4bF46ong=
1802 ListenPort=51820
1803
1804 [WireGuardPeer]
1805 PublicKey=RDf+LSpeEre7YEIKaxg+wbpsNV7du+ktR99uBEtIiCA=
1806 AllowedIPs=fd31:bf08:57cb::/48,192.168.26.0/24
1807 Endpoint=wireguard.example.com:51820</programlisting>
1808     </example>
1809   </refsect1>
1810   <refsect1>
1811     <title>See Also</title>
1812     <para>
1813       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1814       <citerefentry><refentrytitle>systemd-networkd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
1815       <citerefentry><refentrytitle>systemd.link</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1816       <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>
1817     </para>
1818   </refsect1>
1819
1820 </refentry>