man/systemd.netdev.xml

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  23
  24 <refentry id="systemd.netdev" conditional='ENABLE_NETWORKD'>
  25
  26   <refentryinfo>
  27     <title>systemd.network</title>
  28     <productname>systemd</productname>
  29
  30     <authorgroup>
  31       <author>
  32         <contrib>Developer</contrib>
  33         <firstname>Tom</firstname>
  34         <surname>Gundersen</surname>
  35         <email>teg@jklm.no</email>
  36       </author>
  37     </authorgroup>
  38   </refentryinfo>
  39
  40   <refmeta>
  41     <refentrytitle>systemd.netdev</refentrytitle>
  42     <manvolnum>5</manvolnum>
  43   </refmeta>
  44
  45   <refnamediv>
  46     <refname>systemd.netdev</refname>
  47     <refpurpose>Virtual Network Device configuration</refpurpose>
  48   </refnamediv>
  49
  50   <refsynopsisdiv>
  51     <para><filename><replaceable>netdev</replaceable>.netdev</filename></para>
  52   </refsynopsisdiv>
  53
  54   <refsect1>
  55     <title>Description</title>
  56
  57     <para>Network setup is performed by
  58     <citerefentry><refentrytitle>systemd-networkd</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
  59     </para>
  60
  61     <para>The main Virtual Network Device file must have the extension <filename>.netdev</filename>;
  62     other extensions are ignored. Virtual network devices are created as soon as networkd is
  63     started. If a netdev with the specified name already exists, networkd will use that as-is rather
  64     than create its own. Note that the settings of the pre-existing netdev will not be changed by
  65     networkd.</para>
  66
  67     <para>The <filename>.netdev</filename> files are read from the files located in the system
  68     network directory <filename>/usr/lib/systemd/network</filename>, the volatile runtime network
  69     directory <filename>/run/systemd/network</filename> and the local administration network
  70     directory <filename>/etc/systemd/network</filename>. All configuration files are collectively
  71     sorted and processed in lexical order, regardless of the directories in which they live.
  72     However, files with identical filenames replace each other. Files in <filename>/etc</filename>
  73     have the highest priority, files in <filename>/run</filename> take precedence over files with
  74     the same name in <filename>/usr/lib</filename>. This can be used to override a system-supplied
  75     configuration file with a local file if needed. As a special case, an empty file (file size 0)
  76     or symlink with the same name pointing to <filename>/dev/null</filename> disables the
  77     configuration file entirely (it is "masked").</para>
  78
  79     <para>Along with the netdev file <filename>foo.netdev</filename>, a "drop-in" directory
  80     <filename>foo.netdev.d/</filename> may exist. All files with the suffix <literal>.conf</literal>
  81     from this directory will be parsed after the file itself is parsed. This is useful to alter or
  82     add configuration settings, without having to modify the main configuration file. Each drop-in
  83     file must have appropriate section headers.</para>
  84
  85     <para>In addition to <filename>/etc/systemd/network</filename>, drop-in <literal>.d</literal>
  86     directories can be placed in <filename>/usr/lib/systemd/network</filename> or
  87     <filename>/run/systemd/network</filename> directories. Drop-in files in
  88     <filename>/etc</filename> take precedence over those in <filename>/run</filename> which in turn
  89     take precedence over those in <filename>/usr/lib</filename>. Drop-in files under any of these
  90     directories take precedence over the main netdev file wherever located. (Of course, since
  91     <filename>/run</filename> is temporary and <filename>/usr/lib</filename> is for vendors, it is
  92     unlikely drop-ins should be used in either of those places.)</para>
  93   </refsect1>
  94
  95   <refsect1>
  96     <title>Supported netdev kinds</title>
  97
  98     <para>The following kinds of virtual network devices may be
  99     configured in <filename>.netdev</filename> files:</para>
 100
 101     <table>
 102       <title>Supported kinds of virtual network devices</title>
 103
 104       <tgroup cols='2'>
 105         <colspec colname='kind' />
 106         <colspec colname='explanation' />
 107         <thead><row>
 108           <entry>Kind</entry>
 109           <entry>Description</entry>
 110         </row></thead>
 111         <tbody>
 112           <row><entry><varname>bond</varname></entry>
 113           <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>
 114
 115           <row><entry><varname>bridge</varname></entry>
 116           <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>
 117
 118           <row><entry><varname>dummy</varname></entry>
 119           <entry>A dummy device drops all packets sent to it.</entry></row>
 120
 121           <row><entry><varname>gre</varname></entry>
 122           <entry>A Level 3 GRE tunnel over IPv4. See <ulink url="https://tools.ietf.org/html/rfc2784">RFC 2784</ulink> for details.</entry></row>
 123
 124           <row><entry><varname>gretap</varname></entry>
 125           <entry>A Level 2 GRE tunnel over IPv4.</entry></row>
 126
 127           <row><entry><varname>ip6gre</varname></entry>
 128           <entry>A Level 3 GRE tunnel over IPv6.</entry></row>
 129
 130           <row><entry><varname>ip6tnl</varname></entry>
 131           <entry>An IPv4 or IPv6 tunnel over IPv6</entry></row>
 132
 133           <row><entry><varname>ip6gretap</varname></entry>
 134           <entry>A Level 2 GRE tunnel over IPv6.</entry></row>
 135
 136           <row><entry><varname>ipip</varname></entry>
 137           <entry>An IPv4 over IPv4 tunnel.</entry></row>
 138
 139           <row><entry><varname>ipvlan</varname></entry>
 140           <entry>An ipvlan device is a stacked device which receives packets from its underlying device based on IP address filtering.</entry></row>
 141
 142           <row><entry><varname>macvlan</varname></entry>
 143           <entry>A macvlan device is a stacked device which receives packets from its underlying device based on MAC address filtering.</entry></row>
 144
 145           <row><entry><varname>macvtap</varname></entry>
 146           <entry>A macvtap device is a stacked device which receives packets from its underlying device based on MAC address filtering.</entry></row>
 147
 148           <row><entry><varname>sit</varname></entry>
 149           <entry>An IPv6 over IPv4 tunnel.</entry></row>
 150
 151           <row><entry><varname>tap</varname></entry>
 152           <entry>A persistent Level 2 tunnel between a network device and a device node.</entry></row>
 153
 154           <row><entry><varname>tun</varname></entry>
 155           <entry>A persistent Level 3 tunnel between a network device and a device node.</entry></row>
 156
 157           <row><entry><varname>veth</varname></entry>
 158           <entry>An Ethernet tunnel between a pair of network devices.</entry></row>
 159
 160           <row><entry><varname>vlan</varname></entry>
 161           <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>
 162
 163           <row><entry><varname>vti</varname></entry>
 164           <entry>An IPv4 over IPSec tunnel.</entry></row>
 165
 166           <row><entry><varname>vti6</varname></entry>
 167           <entry>An IPv6 over IPSec tunnel.</entry></row>
 168
 169           <row><entry><varname>vxlan</varname></entry>
 170           <entry>A virtual extensible LAN (vxlan), for connecting Cloud computing deployments.</entry></row>
 171
 172           <row><entry><varname>geneve</varname></entry>
 173           <entry>A GEneric NEtwork Virtualization Encapsulation (GENEVE) netdev driver.</entry></row>
 174
 175           <row><entry><varname>vrf</varname></entry>
 176           <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>
 177
 178           <row><entry><varname>vcan</varname></entry>
 179           <entry>The virtual CAN driver (vcan). Similar to the network loopback devices, vcan offers a virtual local CAN interface.</entry></row>
 180
 181         </tbody>
 182       </tgroup>
 183     </table>
 184
 185   </refsect1>
 186
 187   <refsect1>
 188     <title>[Match] Section Options</title>
 189
 190     <para>A virtual network device is only created if the
 191     <literal>[Match]</literal> section matches the current
 192     environment, or if the section is empty. The following keys are
 193     accepted:</para>
 194
 195     <variablelist class='network-directives'>
 196       <varlistentry>
 197         <term><varname>Host=</varname></term>
 198         <listitem>
 199           <para>Matches against the hostname or machine ID of the
 200           host. See <literal>ConditionHost=</literal> in
 201           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 202           for details.
 203           </para>
 204         </listitem>
 205       </varlistentry>
 206       <varlistentry>
 207         <term><varname>Virtualization=</varname></term>
 208         <listitem>
 209           <para>Checks whether the system is executed in a virtualized
 210           environment and optionally test whether it is a specific
 211           implementation. See
 212           <literal>ConditionVirtualization=</literal> in
 213           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 214           for details.
 215           </para>
 216         </listitem>
 217       </varlistentry>
 218       <varlistentry>
 219         <term><varname>KernelCommandLine=</varname></term>
 220         <listitem>
 221           <para>Checks whether a specific kernel command line option
 222           is set (or if prefixed with the exclamation mark unset). See
 223           <literal>ConditionKernelCommandLine=</literal> in
 224           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 225           for details.
 226           </para>
 227         </listitem>
 228       </varlistentry>
 229       <varlistentry>
 230         <term><varname>Architecture=</varname></term>
 231         <listitem>
 232           <para>Checks whether the system is running on a specific
 233           architecture. See <literal>ConditionArchitecture=</literal> in
 234           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 235           for details.
 236           </para>
 237         </listitem>
 238       </varlistentry>
 239     </variablelist>
 240
 241   </refsect1>
 242
 243   <refsect1>
 244     <title>[NetDev] Section Options</title>
 245
 246       <para>The <literal>[NetDev]</literal> section accepts the
 247       following keys:</para>
 248
 249       <variablelist class='network-directives'>
 250         <varlistentry>
 251           <term><varname>Description=</varname></term>
 252           <listitem>
 253             <para>A free-form description of the netdev.</para>
 254           </listitem>
 255         </varlistentry>
 256         <varlistentry>
 257           <term><varname>Name=</varname></term>
 258           <listitem>
 259             <para>The interface name used when creating the netdev.
 260             This option is compulsory.</para>
 261           </listitem>
 262         </varlistentry>
 263         <varlistentry>
 264           <term><varname>Kind=</varname></term>
 265           <listitem>
 266             <para>The netdev kind. This option is compulsory. See the
 267             <literal>Supported netdev kinds</literal> section for the
 268             valid keys.</para>
 269           </listitem>
 270         </varlistentry>
 271         <varlistentry>
 272           <term><varname>MTUBytes=</varname></term>
 273           <listitem>
 274             <para>The maximum transmission unit in bytes to set for
 275             the device. The usual suffixes K, M, G, are supported and
 276             are understood to the base of 1024. This key is not
 277             currently supported for <literal>tun</literal> or
 278             <literal>tap</literal> devices.
 279             </para>
 280           </listitem>
 281         </varlistentry>
 282         <varlistentry>
 283           <term><varname>MACAddress=</varname></term>
 284           <listitem>
 285             <para>The MAC address to use for the device. If none is
 286             given, one is generated based on the interface name and
 287             the
 288             <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
 289             This key is not currently supported for
 290             <literal>tun</literal> or <literal>tap</literal> devices.
 291             </para>
 292           </listitem>
 293         </varlistentry>
 294       </variablelist>
 295   </refsect1>
 296
 297     <refsect1>
 298     <title>[Bridge] Section Options</title>
 299
 300       <para>The <literal>[Bridge]</literal> section only applies for
 301       netdevs of kind <literal>bridge</literal>, and accepts the
 302       following keys:</para>
 303
 304       <variablelist class='network-directives'>
 305         <varlistentry>
 306           <term><varname>HelloTimeSec=</varname></term>
 307           <listitem>
 308             <para>HelloTimeSec specifies the number of seconds between two hello packets
 309             sent out by the root bridge and the designated bridges. Hello packets are
 310             used to communicate information about the topology throughout the entire
 311             bridged local area network.</para>
 312           </listitem>
 313         </varlistentry>
 314         <varlistentry>
 315           <term><varname>MaxAgeSec=</varname></term>
 316           <listitem>
 317             <para>MaxAgeSec specifies the number of seconds of maximum message age.
 318             If the last seen (received) hello packet is more than this number of
 319             seconds old, the bridge in question will start the takeover procedure
 320             in attempt to become the Root Bridge itself.</para>
 321           </listitem>
 322         </varlistentry>
 323         <varlistentry>
 324           <term><varname>ForwardDelaySec=</varname></term>
 325           <listitem>
 326             <para>ForwardDelaySec specifies the number of seconds spent in each
 327             of the Listening and Learning states before the Forwarding state is entered.</para>
 328           </listitem>
 329         </varlistentry>
 330         <varlistentry>
 331           <term><varname>AgeingTimeSec=</varname></term>
 332           <listitem>
 333             <para>This specifies the number of seconds a MAC Address will be kept in
 334             the forwarding database after having a packet received from this MAC Address.</para>
 335           </listitem>
 336         </varlistentry>
 337         <varlistentry>
 338           <term><varname>Priority=</varname></term>
 339           <listitem>
 340             <para>The priority of the bridge. An integer between 0 and 65535. A lower value
 341             means higher priority. The bridge having the lowest priority will be elected as root bridge.</para>
 342           </listitem>
 343         </varlistentry>
 344         <varlistentry>
 345           <term><varname>DefaultPVID=</varname></term>
 346           <listitem>
 347             <para>This specifies the default port VLAN ID of a newly attached bridge port.</para>
 348           </listitem>
 349         </varlistentry>
 350         <varlistentry>
 351           <term><varname>MulticastQuerier=</varname></term>
 352           <listitem>
 353             <para>A boolean. This setting controls the IFLA_BR_MCAST_QUERIER option in the kernel.
 354             If enabled, the kernel will send general ICMP queries from a zero source address.
 355             This feature should allow faster convergence on startup, but it causes some
 356             multicast-aware switches to misbehave and disrupt forwarding of multicast packets.
 357             When unset, the kernel's default setting applies.
 358             </para>
 359           </listitem>
 360         </varlistentry>
 361         <varlistentry>
 362           <term><varname>MulticastSnooping=</varname></term>
 363           <listitem>
 364             <para>A boolean. This setting controls the IFLA_BR_MCAST_SNOOPING option in the kernel.
 365             If enabled, IGMP snooping monitors the Internet Group Management Protocol (IGMP) traffic
 366             between hosts and multicast routers. When unset, the kernel's default setting applies.
 367             </para>
 368           </listitem>
 369         </varlistentry>
 370         <varlistentry>
 371           <term><varname>VLANFiltering=</varname></term>
 372           <listitem>
 373             <para>A boolean. This setting controls the IFLA_BR_VLAN_FILTERING option in the kernel.
 374             If enabled, the bridge will be started in VLAN-filtering mode. When unset, the kernel's
 375             default setting applies.
 376             </para>
 377           </listitem>
 378         </varlistentry>
 379           <varlistentry>
 380           <term><varname>STP=</varname></term>
 381           <listitem>
 382             <para>A boolean. This enables the bridge's Spanning Tree Protocol (STP). When unset,
 383             the kernel's default setting applies.
 384             </para>
 385           </listitem>
 386         </varlistentry>
 387       </variablelist>
 388   </refsect1>
 389
 390   <refsect1>
 391     <title>[VLAN] Section Options</title>
 392
 393       <para>The <literal>[VLAN]</literal> section only applies for
 394       netdevs of kind <literal>vlan</literal>, and accepts the
 395       following key:</para>
 396
 397       <variablelist class='network-directives'>
 398         <varlistentry>
 399           <term><varname>Id=</varname></term>
 400           <listitem>
 401             <para>The VLAN ID to use. An integer in the range 0–4094.
 402             This option is compulsory.</para>
 403           </listitem>
 404         </varlistentry>
 405         <varlistentry>
 406           <term><varname>GVRP=</varname></term>
 407           <listitem>
 408             <para>The Generic VLAN Registration Protocol (GVRP) is a protocol that
 409             allows automatic learning of VLANs on a network. A boolean. When unset,
 410             the kernel's default setting applies.</para>
 411           </listitem>
 412         </varlistentry>
 413         <varlistentry>
 414           <term><varname>MVRP=</varname></term>
 415           <listitem>
 416             <para>Multiple VLAN Registration Protocol (MVRP) formerly known as GARP VLAN
 417             Registration Protocol (GVRP) is a standards-based Layer 2 network protocol,
 418             for automatic configuration of VLAN information on switches. It was defined
 419             in the 802.1ak amendment to 802.1Q-2005. A boolean. When unset, the kernel's
 420             default setting applies.</para>
 421           </listitem>
 422         </varlistentry>
 423         <varlistentry>
 424           <term><varname>LooseBinding=</varname></term>
 425           <listitem>
 426             <para>The VLAN loose binding mode, in which only the operational state is passed
 427             from the parent to the associated VLANs, but the VLAN device state is not changed.
 428             A boolean. When unset, the kernel's default setting applies.</para>
 429           </listitem>
 430         </varlistentry>
 431         <varlistentry>
 432           <term><varname>ReorderHeader=</varname></term>
 433           <listitem>
 434             <para>The VLAN reorder header is set VLAN interfaces behave like physical interfaces.
 435             A boolean. When unset, the kernel's default setting applies.</para>
 436           </listitem>
 437         </varlistentry>
 438       </variablelist>
 439   </refsect1>
 440
 441   <refsect1>
 442     <title>[MACVLAN] Section Options</title>
 443
 444     <para>The <literal>[MACVLAN]</literal> section only applies for
 445     netdevs of kind <literal>macvlan</literal>, and accepts the
 446     following key:</para>
 447
 448     <variablelist class='network-directives'>
 449       <varlistentry>
 450         <term><varname>Mode=</varname></term>
 451         <listitem>
 452           <para>The MACVLAN mode to use. The supported options are
 453           <literal>private</literal>,
 454           <literal>vepa</literal>,
 455           <literal>bridge</literal>, and
 456           <literal>passthru</literal>.
 457           </para>
 458         </listitem>
 459       </varlistentry>
 460     </variablelist>
 461
 462   </refsect1>
 463
 464     <refsect1>
 465     <title>[MACVTAP] Section Options</title>
 466
 467     <para>The <literal>[MACVTAP]</literal> section applies for
 468     netdevs of kind <literal>macvtap</literal> and accepts the
 469     same key as <literal>[MACVLAN]</literal>.</para>
 470
 471     </refsect1>
 472
 473   <refsect1>
 474     <title>[IPVLAN] Section Options</title>
 475
 476     <para>The <literal>[IPVLAN]</literal> section only applies for
 477     netdevs of kind <literal>ipvlan</literal>, and accepts the
 478     following key:</para>
 479
 480     <variablelist class='network-directives'>
 481       <varlistentry>
 482         <term><varname>Mode=</varname></term>
 483           <listitem>
 484             <para>The IPVLAN mode to use. The supported options are
 485             <literal>L2</literal> and <literal>L3</literal>.
 486             </para>
 487           </listitem>
 488       </varlistentry>
 489     </variablelist>
 490
 491   </refsect1>
 492
 493   <refsect1>
 494     <title>[VXLAN] Section Options</title>
 495     <para>The <literal>[VXLAN]</literal> section only applies for
 496     netdevs of kind <literal>vxlan</literal>, and accepts the
 497     following keys:</para>
 498
 499     <variablelist class='network-directives'>
 500       <varlistentry>
 501         <term><varname>Id=</varname></term>
 502         <listitem>
 503           <para>The VXLAN ID to use.</para>
 504         </listitem>
 505       </varlistentry>
 506       <varlistentry>
 507         <term><varname>Remote=</varname></term>
 508         <listitem>
 509           <para>Configures destination multicast group IP address.</para>
 510         </listitem>
 511       </varlistentry>
 512       <varlistentry>
 513         <term><varname>Local=</varname></term>
 514         <listitem>
 515           <para>Configures local IP address.</para>
 516         </listitem>
 517       </varlistentry>
 518         <varlistentry>
 519         <term><varname>TOS=</varname></term>
 520         <listitem>
 521           <para>The Type Of Service byte value for a vxlan interface.</para>
 522         </listitem>
 523       </varlistentry>
 524       <varlistentry>
 525         <term><varname>TTL=</varname></term>
 526         <listitem>
 527           <para>A fixed Time To Live N on Virtual eXtensible Local
 528           Area Network packets. N is a number in the range 1–255. 0
 529           is a special value meaning that packets inherit the TTL
 530           value.</para>
 531         </listitem>
 532       </varlistentry>
 533       <varlistentry>
 534         <term><varname>MacLearning=</varname></term>
 535         <listitem>
 536           <para>A boolean. When true, enables dynamic MAC learning
 537           to discover remote MAC addresses.</para>
 538         </listitem>
 539       </varlistentry>
 540       <varlistentry>
 541         <term><varname>FDBAgeingSec=</varname></term>
 542         <listitem>
 543           <para>The lifetime of Forwarding Database entry learnt by
 544           the kernel, in seconds.</para>
 545         </listitem>
 546       </varlistentry>
 547       <varlistentry>
 548         <term><varname>MaximumFDBEntries=</varname></term>
 549         <listitem>
 550           <para>Configures maximum number of FDB entries.</para>
 551         </listitem>
 552       </varlistentry>
 553       <varlistentry>
 554         <term><varname>ReduceARPProxy=</varname></term>
 555         <listitem>
 556           <para>A boolean. When true, bridge-connected VXLAN tunnel
 557           endpoint answers ARP requests from the local bridge on behalf
 558           of remote Distributed Overlay Virtual Ethernet
 559           <ulink url="https://en.wikipedia.org/wiki/Distributed_Overlay_Virtual_Ethernet">
 560           (DVOE)</ulink> clients. Defaults to false.</para>
 561         </listitem>
 562       </varlistentry>
 563       <varlistentry>
 564         <term><varname>L2MissNotification=</varname></term>
 565         <listitem>
 566           <para>A boolean. When true, enables netlink LLADDR miss
 567           notifications.</para>
 568         </listitem>
 569       </varlistentry>
 570       <varlistentry>
 571         <term><varname>L3MissNotification=</varname></term>
 572         <listitem>
 573           <para>A boolean. When true, enables netlink IP address miss
 574           notifications.</para>
 575         </listitem>
 576       </varlistentry>
 577       <varlistentry>
 578         <term><varname>RouteShortCircuit=</varname></term>
 579         <listitem>
 580           <para>A boolean. When true, route short circuiting is turned
 581           on.</para>
 582         </listitem>
 583       </varlistentry>
 584       <varlistentry>
 585         <term><varname>UDPChecksum=</varname></term>
 586         <listitem>
 587           <para>A boolean. When true, transmitting UDP checksums when doing VXLAN/IPv4 is turned on.</para>
 588         </listitem>
 589       </varlistentry>
 590       <varlistentry>
 591         <term><varname>UDP6ZeroChecksumTx=</varname></term>
 592         <listitem>
 593           <para>A boolean. When true, sending zero checksums in VXLAN/IPv6 is turned on.</para>
 594         </listitem>
 595       </varlistentry>
 596       <varlistentry>
 597         <term><varname>UDP6ZeroChecksumRx=</varname></term>
 598         <listitem>
 599           <para>A boolean. When true, receiving zero checksums in VXLAN/IPv6 is turned on.</para>
 600         </listitem>
 601       </varlistentry>
 602       <varlistentry>
 603         <term><varname>RemoteChecksumTx=</varname></term>
 604         <listitem>
 605           <para>A boolean. When true, remote transmit checksum offload of VXLAN is turned on.</para>
 606         </listitem>
 607       </varlistentry>
 608       <varlistentry>
 609         <term><varname>RemoteChecksumRx=</varname></term>
 610         <listitem>
 611           <para>A boolean. When true, remote receive checksum offload in VXLAN is turned on.</para>
 612         </listitem>
 613       </varlistentry>
 614     <varlistentry>
 615       <term><varname>GroupPolicyExtension=</varname></term>
 616       <listitem>
 617         <para>A boolean. When true, it enables Group Policy VXLAN extension security label mechanism
 618         across network peers based on VXLAN. For details about the Group Policy VXLAN, see the
 619         <ulink url="https://tools.ietf.org/html/draft-smith-vxlan-group-policy">
 620         VXLAN Group Policy </ulink> document. Defaults to false.</para>
 621       </listitem>
 622     </varlistentry>
 623     <varlistentry>
 624       <term><varname>DestinationPort=</varname></term>
 625       <listitem>
 626         <para>Configures the default destination UDP port on a per-device basis.
 627         If destination port is not specified then Linux kernel default will be used.
 628         Set destination port 4789 to get the IANA assigned value. If not set or if the
 629         destination port is assigned the empty string the default port of 4789 is used.</para>
 630       </listitem>
 631     </varlistentry>
 632     <varlistentry>
 633       <term><varname>PortRange=</varname></term>
 634         <listitem>
 635           <para>Configures VXLAN port range. VXLAN bases source
 636           UDP port based on flow to help the receiver to be able
 637           to load balance based on outer header flow. It
 638           restricts the port range to the normal UDP local
 639           ports, and allows overriding via configuration.</para>
 640         </listitem>
 641       </varlistentry>
 642     <varlistentry>
 643       <term><varname>FlowLabel=</varname></term>
 644         <listitem>
 645           <para>Specifies the flow label to use in outgoing packets.
 646           The valid range is 0-1048575.
 647           </para>
 648         </listitem>
 649       </varlistentry>
 650     </variablelist>
 651   </refsect1>
 652   <refsect1>
 653     <title>[GENEVE] Section Options</title>
 654     <para>The <literal>[GENEVE]</literal> section only applies for
 655     netdevs of kind <literal>geneve</literal>, and accepts the
 656     following keys:</para>
 657
 658     <variablelist class='network-directives'>
 659       <varlistentry>
 660         <term><varname>Id=</varname></term>
 661         <listitem>
 662           <para>Specifies the Virtual Network Identifer (VNI) to use. Ranges [0-16777215].</para>
 663         </listitem>
 664       </varlistentry>
 665       <varlistentry>
 666         <term><varname>Remote=</varname></term>
 667         <listitem>
 668           <para>Specifies the unicast destination IP address to use in outgoing packets.</para>
 669         </listitem>
 670       </varlistentry>
 671       <varlistentry>
 672         <term><varname>TOS=</varname></term>
 673         <listitem>
 674           <para>Specifies the TOS value to use in outgoing packets. Ranges [1-255].</para>
 675         </listitem>
 676       </varlistentry>
 677       <varlistentry>
 678         <term><varname>TTL=</varname></term>
 679         <listitem>
 680           <para>Specifies the TTL value to use in outgoing packets. Ranges [1-255].</para>
 681         </listitem>
 682       </varlistentry>
 683       <varlistentry>
 684         <term><varname>UDPChecksum=</varname></term>
 685         <listitem>
 686           <para>A boolean. When true, specifies if UDP checksum is calculated for transmitted packets over IPv4.</para>
 687         </listitem>
 688       </varlistentry>
 689       <varlistentry>
 690         <term><varname>UDP6ZeroChecksumTx=</varname></term>
 691         <listitem>
 692           <para>A boolean. When true, skip UDP checksum calculation for transmitted packets over IPv6.</para>
 693         </listitem>
 694       </varlistentry>
 695       <varlistentry>
 696         <term><varname>UDP6ZeroChecksumRx=</varname></term>
 697         <listitem>
 698           <para>A boolean. When true, allows incoming UDP packets over IPv6 with zero checksum field.</para>
 699         </listitem>
 700       </varlistentry>
 701     <varlistentry>
 702       <term><varname>DestinationPort=</varname></term>
 703       <listitem>
 704         <para>Specifies destination port. Defaults to 6081. If not set or assigned the empty string, the default
 705         port of 6081 is used.</para>
 706       </listitem>
 707     </varlistentry>
 708     <varlistentry>
 709       <term><varname>FlowLabel=</varname></term>
 710         <listitem>
 711           <para>Specifies the flow label to use in outgoing packets.</para>
 712         </listitem>
 713       </varlistentry>
 714     </variablelist>
 715   </refsect1>
 716   <refsect1>
 717     <title>[Tunnel] Section Options</title>
 718
 719     <para>The <literal>[Tunnel]</literal> section only applies for
 720     netdevs of kind
 721     <literal>ipip</literal>,
 722     <literal>sit</literal>,
 723     <literal>gre</literal>,
 724     <literal>gretap</literal>,
 725     <literal>ip6gre</literal>,
 726     <literal>ip6gretap</literal>,
 727     <literal>vti</literal>,
 728     <literal>vti6</literal>, and
 729     <literal>ip6tnl</literal> and accepts
 730     the following keys:</para>
 731
 732     <variablelist class='network-directives'>
 733       <varlistentry>
 734         <term><varname>Local=</varname></term>
 735         <listitem>
 736           <para>A static local address for tunneled packets. It must
 737           be an address on another interface of this host.</para>
 738         </listitem>
 739       </varlistentry>
 740       <varlistentry>
 741         <term><varname>Remote=</varname></term>
 742         <listitem>
 743           <para>The remote endpoint of the tunnel.</para>
 744         </listitem>
 745       </varlistentry>
 746       <varlistentry>
 747         <term><varname>TOS=</varname></term>
 748         <listitem>
 749           <para>The Type Of Service byte value for a tunnel interface.
 750           For details about the TOS, see the
 751           <ulink url="http://tools.ietf.org/html/rfc1349"> Type of
 752           Service in the Internet Protocol Suite </ulink> document.
 753           </para>
 754         </listitem>
 755       </varlistentry>
 756       <varlistentry>
 757         <term><varname>TTL=</varname></term>
 758         <listitem>
 759           <para>A fixed Time To Live N on tunneled packets. N is a
 760           number in the range 1–255. 0 is a special value meaning that
 761           packets inherit the TTL value. The default value for IPv4
 762           tunnels is: inherit. The default value for IPv6 tunnels is
 763           64.</para>
 764         </listitem>
 765       </varlistentry>
 766       <varlistentry>
 767         <term><varname>DiscoverPathMTU=</varname></term>
 768         <listitem>
 769           <para>A boolean. When true, enables Path MTU Discovery on
 770           the tunnel.</para>
 771         </listitem>
 772       </varlistentry>
 773       <varlistentry>
 774         <term><varname>IPv6FlowLabel=</varname></term>
 775         <listitem>
 776           <para>Configures the 20-bit flow label (see <ulink url="https://tools.ietf.org/html/rfc6437">
 777           RFC 6437</ulink>) field in the IPv6 header (see <ulink url="https://tools.ietf.org/html/rfc2460">
 778           RFC 2460</ulink>), which is used by a node to label packets of a flow.
 779           It is only used for IPv6 tunnels.
 780           A flow label of zero is used to indicate packets that have
 781           not been labeled.
 782           It can be configured to a value in the range 0–0xFFFFF, or be
 783           set to <literal>inherit</literal>, in which case the original flowlabel is used.</para>
 784         </listitem>
 785       </varlistentry>
 786       <varlistentry>
 787         <term><varname>CopyDSCP=</varname></term>
 788         <listitem>
 789           <para>A boolean. When true, the Differentiated Service Code
 790           Point (DSCP) field will be copied to the inner header from
 791           outer header during the decapsulation of an IPv6 tunnel
 792           packet. DSCP is a field in an IP packet that enables different
 793           levels of service to be assigned to network traffic.
 794           Defaults to <literal>no</literal>.
 795           </para>
 796         </listitem>
 797       </varlistentry>
 798       <varlistentry>
 799         <term><varname>EncapsulationLimit=</varname></term>
 800         <listitem>
 801           <para>The Tunnel Encapsulation Limit option specifies how many additional
 802           levels of encapsulation are permitted to be prepended to the packet.
 803           For example, a Tunnel Encapsulation Limit option containing a limit
 804           value of zero means that a packet carrying that option may not enter
 805           another tunnel before exiting the current tunnel.
 806           (see <ulink url="https://tools.ietf.org/html/rfc2473#section-4.1.1"> RFC 2473</ulink>).
 807           The valid range is 0–255 and <literal>none</literal>. Defaults to 4.
 808         </para>
 809         </listitem>
 810       </varlistentry>
 811       <varlistentry>
 812         <term><varname>Key=</varname></term>
 813         <listitem>
 814           <para>The <varname>Key=</varname> parameter specifies the same key to use in
 815           both directions (<varname>InputKey=</varname> and <varname>OutputKey=</varname>).
 816           The <varname>Key=</varname> is either a number or an IPv4 address-like dotted quad.
 817           It is used as mark-configured SAD/SPD entry as part of the lookup key (both in data
 818           and control path) in ip xfrm (framework used to implement IPsec protocol).
 819           See <ulink url="http://man7.org/linux/man-pages/man8/ip-xfrm.8.html">
 820           ip-xfrm — transform configuration</ulink> for details. It is only used for VTI/VTI6
 821           tunnels.</para>
 822         </listitem>
 823       </varlistentry>
 824       <varlistentry>
 825         <term><varname>InputKey=</varname></term>
 826         <listitem>
 827           <para>The <varname>InputKey=</varname> parameter specifies the key to use for input.
 828           The format is same as <varname>Key=</varname>. It is only used for VTI/VTI6 tunnels.</para>
 829         </listitem>
 830       </varlistentry>
 831       <varlistentry>
 832         <term><varname>OutputKey=</varname></term>
 833         <listitem>
 834           <para>The <varname>OutputKey=</varname> parameter specifies the key to use for output.
 835           The format is same as <varname>Key=</varname>. It is only used for VTI/VTI6 tunnels.</para>
 836         </listitem>
 837       </varlistentry>
 838       <varlistentry>
 839         <term><varname>Mode=</varname></term>
 840         <listitem>
 841           <para>An <literal>ip6tnl</literal> tunnel can be in one of three
 842           modes
 843           <literal>ip6ip6</literal> for IPv6 over IPv6,
 844           <literal>ipip6</literal> for IPv4 over IPv6 or
 845           <literal>any</literal> for either.
 846           </para>
 847         </listitem>
 848       </varlistentry>
 849     </variablelist>
 850   </refsect1>
 851   <refsect1>
 852     <title>[Peer] Section Options</title>
 853
 854       <para>The <literal>[Peer]</literal> section only applies for
 855       netdevs of kind <literal>veth</literal> and accepts the
 856       following keys:</para>
 857
 858       <variablelist class='network-directives'>
 859         <varlistentry>
 860           <term><varname>Name=</varname></term>
 861           <listitem>
 862             <para>The interface name used when creating the netdev.
 863             This option is compulsory.</para>
 864           </listitem>
 865         </varlistentry>
 866         <varlistentry>
 867           <term><varname>MACAddress=</varname></term>
 868           <listitem>
 869             <para>The peer MACAddress, if not set, it is generated in
 870             the same way as the MAC address of the main
 871             interface.</para>
 872           </listitem>
 873         </varlistentry>
 874       </variablelist>
 875   </refsect1>
 876   <refsect1>
 877     <title>[Tun] Section Options</title>
 878
 879     <para>The <literal>[Tun]</literal> section only applies for
 880     netdevs of kind <literal>tun</literal>, and accepts the following
 881     keys:</para>
 882
 883     <variablelist class='network-directives'>
 884       <varlistentry>
 885         <term><varname>OneQueue=</varname></term>
 886         <listitem><para>Takes a boolean argument. Configures whether
 887         all packets are queued at the device (enabled), or a fixed
 888         number of packets are queued at the device and the rest at the
 889         <literal>qdisc</literal>. Defaults to
 890         <literal>no</literal>.</para>
 891         </listitem>
 892       </varlistentry>
 893       <varlistentry>
 894         <term><varname>MultiQueue=</varname></term>
 895         <listitem><para>Takes a boolean argument. Configures whether
 896         to use multiple file descriptors (queues) to parallelize
 897         packets sending and receiving. Defaults to
 898         <literal>no</literal>.</para>
 899         </listitem>
 900       </varlistentry>
 901       <varlistentry>
 902         <term><varname>PacketInfo=</varname></term>
 903         <listitem><para>Takes a boolean argument. Configures whether
 904         packets should be prepended with four extra bytes (two flag
 905         bytes and two protocol bytes). If disabled, it indicates that
 906         the packets will be pure IP packets. Defaults to
 907         <literal>no</literal>.</para>
 908         </listitem>
 909       </varlistentry>
 910       <varlistentry>
 911         <term><varname>VNetHeader=</varname></term>
 912         <listitem><para>Takes a boolean argument. Configures
 913         IFF_VNET_HDR flag for a tap device. It allows sending
 914         and receiving larger Generic Segmentation Offload (GSO)
 915         packets. This may increase throughput significantly.
 916         Defaults to
 917         <literal>no</literal>.</para>
 918         </listitem>
 919       </varlistentry>
 920       <varlistentry>
 921         <term><varname>User=</varname></term>
 922         <listitem><para>User to grant access to the
 923         <filename>/dev/net/tun</filename> device.</para>
 924         </listitem>
 925       </varlistentry>
 926       <varlistentry>
 927         <term><varname>Group=</varname></term>
 928         <listitem><para>Group to grant access to the
 929         <filename>/dev/net/tun</filename> device.</para>
 930         </listitem>
 931       </varlistentry>
 932
 933     </variablelist>
 934
 935   </refsect1>
 936
 937   <refsect1>
 938     <title>[Tap] Section Options</title>
 939
 940     <para>The <literal>[Tap]</literal> section only applies for
 941     netdevs of kind <literal>tap</literal>, and accepts the same keys
 942     as the <literal>[Tun]</literal> section.</para>
 943   </refsect1>
 944
 945   <refsect1>
 946     <title>[Bond] Section Options</title>
 947
 948     <para>The <literal>[Bond]</literal> section accepts the following
 949     key:</para>
 950
 951     <variablelist class='network-directives'>
 952       <varlistentry>
 953         <term><varname>Mode=</varname></term>
 954         <listitem>
 955           <para>Specifies one of the bonding policies. The default is
 956           <literal>balance-rr</literal> (round robin). Possible values are
 957           <literal>balance-rr</literal>,
 958           <literal>active-backup</literal>,
 959           <literal>balance-xor</literal>,
 960           <literal>broadcast</literal>,
 961           <literal>802.3ad</literal>,
 962           <literal>balance-tlb</literal>, and
 963           <literal>balance-alb</literal>.
 964           </para>
 965         </listitem>
 966       </varlistentry>
 967
 968       <varlistentry>
 969         <term><varname>TransmitHashPolicy=</varname></term>
 970         <listitem>
 971           <para>Selects the transmit hash policy to use for slave
 972           selection in balance-xor, 802.3ad, and tlb modes. Possible
 973           values are
 974           <literal>layer2</literal>,
 975           <literal>layer3+4</literal>,
 976           <literal>layer2+3</literal>,
 977           <literal>encap2+3</literal>, and
 978           <literal>encap3+4</literal>.
 979           </para>
 980         </listitem>
 981       </varlistentry>
 982
 983       <varlistentry>
 984         <term><varname>LACPTransmitRate=</varname></term>
 985         <listitem>
 986           <para>Specifies the rate with which link partner transmits
 987           Link Aggregation Control Protocol Data Unit packets in
 988           802.3ad mode. Possible values are <literal>slow</literal>,
 989           which requests partner to transmit LACPDUs every 30 seconds,
 990           and <literal>fast</literal>, which requests partner to
 991           transmit LACPDUs every second. The default value is
 992           <literal>slow</literal>.</para>
 993         </listitem>
 994       </varlistentry>
 995
 996       <varlistentry>
 997         <term><varname>MIIMonitorSec=</varname></term>
 998         <listitem>
 999           <para>Specifies the frequency that Media Independent
1000           Interface link monitoring will occur. A value of zero
1001           disables MII link monitoring. This value is rounded down to
1002           the nearest millisecond. The default value is 0.</para>
1003         </listitem>
1004       </varlistentry>
1005
1006       <varlistentry>
1007         <term><varname>UpDelaySec=</varname></term>
1008         <listitem>
1009           <para>Specifies the delay before a link is enabled after a
1010           link up status has been detected. This value is rounded down
1011           to a multiple of MIIMonitorSec. The default value is
1012           0.</para>
1013         </listitem>
1014       </varlistentry>
1015
1016       <varlistentry>
1017         <term><varname>DownDelaySec=</varname></term>
1018         <listitem>
1019           <para>Specifies the delay before a link is disabled after a
1020           link down status has been detected. This value is rounded
1021           down to a multiple of MIIMonitorSec. The default value is
1022           0.</para>
1023         </listitem>
1024       </varlistentry>
1025
1026       <varlistentry>
1027         <term><varname>LearnPacketIntervalSec=</varname></term>
1028         <listitem>
1029           <para>Specifies the number of seconds between instances where the bonding
1030           driver sends learning packets to each slave peer switch.
1031           The valid range is 1–0x7fffffff; the default value is 1. This option
1032           has an effect only for the balance-tlb and balance-alb modes.</para>
1033         </listitem>
1034       </varlistentry>
1035
1036       <varlistentry>
1037         <term><varname>AdSelect=</varname></term>
1038         <listitem>
1039           <para>Specifies the 802.3ad aggregation selection logic to use. Possible values are
1040           <literal>stable</literal>,
1041           <literal>bandwidth</literal> and
1042           <literal>count</literal>.
1043           </para>
1044         </listitem>
1045       </varlistentry>
1046
1047       <varlistentry>
1048         <term><varname>FailOverMACPolicy=</varname></term>
1049         <listitem>
1050           <para>Specifies whether the active-backup mode should set all slaves to
1051           the same MAC address at the time of enslavement or, when enabled, to perform special handling of the
1052           bond's MAC address in accordance with the selected policy. The default policy is none.
1053           Possible values are
1054           <literal>none</literal>,
1055           <literal>active</literal> and
1056           <literal>follow</literal>.
1057           </para>
1058         </listitem>
1059       </varlistentry>
1060
1061       <varlistentry>
1062         <term><varname>ARPValidate=</varname></term>
1063         <listitem>
1064           <para>Specifies whether or not ARP probes and replies should be
1065           validated in any mode that supports ARP monitoring, or whether
1066           non-ARP traffic should be filtered (disregarded) for link
1067           monitoring purposes. Possible values are
1068           <literal>none</literal>,
1069           <literal>active</literal>,
1070           <literal>backup</literal> and
1071           <literal>all</literal>.
1072           </para>
1073         </listitem>
1074       </varlistentry>
1075
1076       <varlistentry>
1077         <term><varname>ARPIntervalSec=</varname></term>
1078         <listitem>
1079           <para>Specifies the ARP link monitoring frequency in milliseconds.
1080           A value of 0 disables ARP monitoring. The default value is 0.
1081           </para>
1082         </listitem>
1083       </varlistentry>
1084
1085       <varlistentry>
1086         <term><varname>ARPIPTargets=</varname></term>
1087         <listitem>
1088           <para>Specifies the IP addresses to use as ARP monitoring peers when
1089           ARPIntervalSec is greater than 0. These are the targets of the ARP request
1090           sent to determine the health of the link to the targets.
1091           Specify these values in IPv4 dotted decimal format. At least one IP
1092           address must be given for ARP monitoring to function. The
1093           maximum number of targets that can be specified is 16. The
1094           default value is no IP addresses.
1095           </para>
1096         </listitem>
1097       </varlistentry>
1098
1099       <varlistentry>
1100         <term><varname>ARPAllTargets=</varname></term>
1101         <listitem>
1102           <para>Specifies the quantity of ARPIPTargets that must be reachable
1103           in order for the ARP monitor to consider a slave as being up.
1104           This option affects only active-backup mode for slaves with
1105           ARPValidate enabled. Possible values are
1106           <literal>any</literal> and
1107           <literal>all</literal>.
1108           </para>
1109         </listitem>
1110       </varlistentry>
1111
1112       <varlistentry>
1113         <term><varname>PrimaryReselectPolicy=</varname></term>
1114         <listitem>
1115           <para>Specifies the reselection policy for the primary slave.  This
1116           affects how the primary slave is chosen to become the active slave
1117           when failure of the active slave or recovery of the primary slave
1118           occurs. This option is designed to prevent flip-flopping between
1119           the primary slave and other slaves.  Possible values are
1120           <literal>always</literal>,
1121           <literal>better</literal> and
1122           <literal>failure</literal>.
1123           </para>
1124         </listitem>
1125       </varlistentry>
1126
1127       <varlistentry>
1128         <term><varname>ResendIGMP=</varname></term>
1129         <listitem>
1130           <para>Specifies the number of IGMP membership reports to be issued after
1131           a failover event. One membership report is issued immediately after
1132           the failover, subsequent packets are sent in each 200ms interval.
1133           The valid range is 0–255. Defaults to 1. A value of 0
1134           prevents the IGMP membership report from being issued in response
1135           to the failover event.
1136           </para>
1137         </listitem>
1138       </varlistentry>
1139
1140       <varlistentry>
1141         <term><varname>PacketsPerSlave=</varname></term>
1142         <listitem>
1143           <para>Specify the number of packets to transmit through a slave before
1144             moving to the next one. When set to 0, then a slave is chosen at
1145             random. The valid range is 0–65535. Defaults to 1. This option
1146             only has effect when in balance-rr mode.
1147           </para>
1148         </listitem>
1149       </varlistentry>
1150
1151       <varlistentry>
1152         <term><varname>GratuitousARP=</varname></term>
1153         <listitem>
1154           <para>Specify the number of peer notifications (gratuitous ARPs and
1155             unsolicited IPv6 Neighbor Advertisements) to be issued after a
1156             failover event.  As soon as the link is up on the new slave,
1157             a peer notification is sent on the  bonding device and each
1158             VLAN sub-device.  This is repeated at each link monitor interval
1159             (ARPIntervalSec or MIIMonitorSec, whichever is active) if the number is
1160             greater than 1. The valid range is 0–255. The default value is 1.
1161             These options affect only the active-backup mode.
1162           </para>
1163         </listitem>
1164       </varlistentry>
1165
1166       <varlistentry>
1167         <term><varname>AllSlavesActive=</varname></term>
1168         <listitem>
1169           <para>A boolean. Specifies that duplicate frames (received on inactive ports)
1170           should be dropped when false, or delivered when true. Normally, bonding will drop
1171           duplicate frames (received on inactive ports), which is desirable for
1172           most users. But there are some times it is nice to allow duplicate
1173           frames to be delivered. The default value is false (drop duplicate frames
1174           received on inactive ports).
1175           </para>
1176         </listitem>
1177       </varlistentry>
1178
1179       <varlistentry>
1180         <term><varname>MinLinks=</varname></term>
1181         <listitem>
1182           <para>Specifies the minimum number of links that must be active before
1183           asserting carrier. The default value is 0.
1184           </para>
1185         </listitem>
1186       </varlistentry>
1187
1188       <varlistentry>
1189         <term><varname>ActiveSlave=</varname></term>
1190         <listitem>
1191           <para>A boolean. Specifies the new active slave. The <literal>ActiveSlave=</literal>
1192           option is only valid for following modes:
1193           <literal>active-backup</literal>,
1194           <literal>balance-alb</literal> and
1195           <literal>balance-tlb</literal>. Defaults to false.
1196           </para>
1197         </listitem>
1198       </varlistentry>
1199
1200       <varlistentry>
1201         <term><varname>PrimarySlave=</varname></term>
1202         <listitem>
1203           <para>A boolean. Specifies which slave is the primary device. The specified
1204           device will always be the active slave while it is available. Only when the
1205           primary is off-line will alternate devices be used.  This is useful when
1206           one slave is preferred over another, e.g. when one slave has higher throughput
1207           than another. The <literal>PrimarySlave=</literal> option is only valid for
1208           following modes:
1209           <literal>active-backup</literal>,
1210           <literal>balance-alb</literal> and
1211           <literal>balance-tlb</literal>. Defaults to false.
1212           </para>
1213         </listitem>
1214       </varlistentry>
1215     </variablelist>
1216
1217     <para>For more detail information see
1218     <ulink url="https://www.kernel.org/doc/Documentation/networking/bonding.txt">
1219     Linux Ethernet Bonding Driver HOWTO</ulink></para>
1220
1221   </refsect1>
1222
1223   <refsect1>
1224     <title>Example</title>
1225     <example>
1226       <title>/etc/systemd/network/25-bridge.netdev</title>
1227
1228       <programlisting>[NetDev]
1229 Name=bridge0
1230 Kind=bridge</programlisting>
1231     </example>
1232
1233     <example>
1234       <title>/etc/systemd/network/25-vlan1.netdev</title>
1235
1236       <programlisting>[Match]
1237 Virtualization=no
1238
1239 [NetDev]
1240 Name=vlan1
1241 Kind=vlan
1242
1243 [VLAN]
1244 Id=1</programlisting>
1245     </example>
1246     <example>
1247       <title>/etc/systemd/network/25-ipip.netdev</title>
1248       <programlisting>[NetDev]
1249 Name=ipip-tun
1250 Kind=ipip
1251 MTUBytes=1480
1252
1253 [Tunnel]
1254 Local=192.168.223.238
1255 Remote=192.169.224.239
1256 TTL=64</programlisting>
1257     </example>
1258     <example>
1259       <title>/etc/systemd/network/25-tap.netdev</title>
1260       <programlisting>[NetDev]
1261 Name=tap-test
1262 Kind=tap
1263
1264 [Tap]
1265 MultiQueue=true
1266 PacketInfo=true</programlisting> </example>
1267
1268     <example>
1269       <title>/etc/systemd/network/25-sit.netdev</title>
1270       <programlisting>[NetDev]
1271 Name=sit-tun
1272 Kind=sit
1273 MTUBytes=1480
1274
1275 [Tunnel]
1276 Local=10.65.223.238
1277 Remote=10.65.223.239</programlisting>
1278     </example>
1279
1280     <example>
1281       <title>/etc/systemd/network/25-gre.netdev</title>
1282       <programlisting>[NetDev]
1283 Name=gre-tun
1284 Kind=gre
1285 MTUBytes=1480
1286
1287 [Tunnel]
1288 Local=10.65.223.238
1289 Remote=10.65.223.239</programlisting>
1290     </example>
1291
1292     <example>
1293       <title>/etc/systemd/network/25-vti.netdev</title>
1294
1295       <programlisting>[NetDev]
1296 Name=vti-tun
1297 Kind=vti
1298 MTUBytes=1480
1299
1300 [Tunnel]
1301 Local=10.65.223.238
1302 Remote=10.65.223.239</programlisting>
1303     </example>
1304
1305     <example>
1306       <title>/etc/systemd/network/25-veth.netdev</title>
1307       <programlisting>[NetDev]
1308 Name=veth-test
1309 Kind=veth
1310
1311 [Peer]
1312 Name=veth-peer</programlisting>
1313     </example>
1314
1315     <example>
1316       <title>/etc/systemd/network/25-bond.netdev</title>
1317       <programlisting>[NetDev]
1318 Name=bond1
1319 Kind=bond
1320
1321 [Bond]
1322 Mode=802.3ad
1323 TransmitHashPolicy=layer3+4
1324 MIIMonitorSec=1s
1325 LACPTransmitRate=fast
1326 </programlisting>
1327     </example>
1328
1329     <example>
1330       <title>/etc/systemd/network/25-dummy.netdev</title>
1331       <programlisting>[NetDev]
1332 Name=dummy-test
1333 Kind=dummy
1334 MACAddress=12:34:56:78:9a:bc</programlisting>
1335     </example>
1336     <example>
1337       <title>/etc/systemd/network/25-vrf.netdev</title>
1338       <para>Create a VRF interface with table 42.</para>
1339       <programlisting>[NetDev]
1340 Name=vrf-test
1341 Kind=vrf
1342
1343 [VRF]
1344 TableId=42</programlisting>
1345     </example>
1346
1347     <example>
1348       <title>/etc/systemd/network/25-macvtap.netdev</title>
1349       <para>Create a MacVTap device.</para>
1350       <programlisting>[NetDev]
1351 Name=macvtap-test
1352 Kind=macvtap
1353       </programlisting>
1354     </example>
1355   </refsect1>
1356   <refsect1>
1357     <title>See Also</title>
1358     <para>
1359       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1360       <citerefentry><refentrytitle>systemd-networkd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
1361       <citerefentry><refentrytitle>systemd.link</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1362       <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>
1363     </para>
1364   </refsect1>
1365
1366 </refentry>