man/systemd.netdev.xml

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  10   Copyright 2013 Tom Gundersen
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  25
  26 <refentry id="systemd.netdev" conditional='ENABLE_NETWORKD'>
  27
  28   <refentryinfo>
  29     <title>systemd.network</title>
  30     <productname>systemd</productname>
  31
  32     <authorgroup>
  33       <author>
  34         <contrib>Developer</contrib>
  35         <firstname>Tom</firstname>
  36         <surname>Gundersen</surname>
  37         <email>teg@jklm.no</email>
  38       </author>
  39     </authorgroup>
  40   </refentryinfo>
  41
  42   <refmeta>
  43     <refentrytitle>systemd.netdev</refentrytitle>
  44     <manvolnum>5</manvolnum>
  45   </refmeta>
  46
  47   <refnamediv>
  48     <refname>systemd.netdev</refname>
  49     <refpurpose>Virtual Network Device configuration</refpurpose>
  50   </refnamediv>
  51
  52   <refsynopsisdiv>
  53     <para><filename><replaceable>netdev</replaceable>.netdev</filename></para>
  54   </refsynopsisdiv>
  55
  56   <refsect1>
  57     <title>Description</title>
  58
  59     <para>Network setup is performed by
  60     <citerefentry><refentrytitle>systemd-networkd</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
  61     </para>
  62
  63     <para>The main Virtual Network Device file must have the extension <filename>.netdev</filename>;
  64     other extensions are ignored. Virtual network devices are created as soon as networkd is
  65     started. If a netdev with the specified name already exists, networkd will use that as-is rather
  66     than create its own. Note that the settings of the pre-existing netdev will not be changed by
  67     networkd.</para>
  68
  69     <para>The <filename>.netdev</filename> files are read from the files located in the system
  70     network directory <filename>/usr/lib/systemd/network</filename>, the volatile runtime network
  71     directory <filename>/run/systemd/network</filename> and the local administration network
  72     directory <filename>/etc/systemd/network</filename>. All configuration files are collectively
  73     sorted and processed in lexical order, regardless of the directories in which they live.
  74     However, files with identical filenames replace each other. Files in <filename>/etc</filename>
  75     have the highest priority, files in <filename>/run</filename> take precedence over files with
  76     the same name in <filename>/usr/lib</filename>. This can be used to override a system-supplied
  77     configuration file with a local file if needed. As a special case, an empty file (file size 0)
  78     or symlink with the same name pointing to <filename>/dev/null</filename> disables the
  79     configuration file entirely (it is "masked").</para>
  80
  81     <para>Along with the netdev file <filename>foo.netdev</filename>, a "drop-in" directory
  82     <filename>foo.netdev.d/</filename> may exist. All files with the suffix <literal>.conf</literal>
  83     from this directory will be parsed after the file itself is parsed. This is useful to alter or
  84     add configuration settings, without having to modify the main configuration file. Each drop-in
  85     file must have appropriate section headers.</para>
  86
  87     <para>In addition to <filename>/etc/systemd/network</filename>, drop-in <literal>.d</literal>
  88     directories can be placed in <filename>/usr/lib/systemd/network</filename> or
  89     <filename>/run/systemd/network</filename> directories. Drop-in files in
  90     <filename>/etc</filename> take precedence over those in <filename>/run</filename> which in turn
  91     take precedence over those in <filename>/usr/lib</filename>. Drop-in files under any of these
  92     directories take precedence over the main netdev file wherever located. (Of course, since
  93     <filename>/run</filename> is temporary and <filename>/usr/lib</filename> is for vendors, it is
  94     unlikely drop-ins should be used in either of those places.)</para>
  95   </refsect1>
  96
  97   <refsect1>
  98     <title>Supported netdev kinds</title>
  99
 100     <para>The following kinds of virtual network devices may be
 101     configured in <filename>.netdev</filename> files:</para>
 102
 103     <table>
 104       <title>Supported kinds of virtual network devices</title>
 105
 106       <tgroup cols='2'>
 107         <colspec colname='kind' />
 108         <colspec colname='explanation' />
 109         <thead><row>
 110           <entry>Kind</entry>
 111           <entry>Description</entry>
 112         </row></thead>
 113         <tbody>
 114           <row><entry><varname>bond</varname></entry>
 115           <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>
 116
 117           <row><entry><varname>bridge</varname></entry>
 118           <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>
 119
 120           <row><entry><varname>dummy</varname></entry>
 121           <entry>A dummy device drops all packets sent to it.</entry></row>
 122
 123           <row><entry><varname>gre</varname></entry>
 124           <entry>A Level 3 GRE tunnel over IPv4. See <ulink url="https://tools.ietf.org/html/rfc2784">RFC 2784</ulink> for details.</entry></row>
 125
 126           <row><entry><varname>gretap</varname></entry>
 127           <entry>A Level 2 GRE tunnel over IPv4.</entry></row>
 128
 129           <row><entry><varname>ip6gre</varname></entry>
 130           <entry>A Level 3 GRE tunnel over IPv6.</entry></row>
 131
 132           <row><entry><varname>ip6tnl</varname></entry>
 133           <entry>An IPv4 or IPv6 tunnel over IPv6</entry></row>
 134
 135           <row><entry><varname>ip6gretap</varname></entry>
 136           <entry>A Level 2 GRE tunnel over IPv6.</entry></row>
 137
 138           <row><entry><varname>ipip</varname></entry>
 139           <entry>An IPv4 over IPv4 tunnel.</entry></row>
 140
 141           <row><entry><varname>ipvlan</varname></entry>
 142           <entry>An ipvlan device is a stacked device which receives packets from its underlying device based on IP address filtering.</entry></row>
 143
 144           <row><entry><varname>macvlan</varname></entry>
 145           <entry>A macvlan device is a stacked device which receives packets from its underlying device based on MAC address filtering.</entry></row>
 146
 147           <row><entry><varname>macvtap</varname></entry>
 148           <entry>A macvtap device is a stacked device which receives packets from its underlying device based on MAC address filtering.</entry></row>
 149
 150           <row><entry><varname>sit</varname></entry>
 151           <entry>An IPv6 over IPv4 tunnel.</entry></row>
 152
 153           <row><entry><varname>tap</varname></entry>
 154           <entry>A persistent Level 2 tunnel between a network device and a device node.</entry></row>
 155
 156           <row><entry><varname>tun</varname></entry>
 157           <entry>A persistent Level 3 tunnel between a network device and a device node.</entry></row>
 158
 159           <row><entry><varname>veth</varname></entry>
 160           <entry>An Ethernet tunnel between a pair of network devices.</entry></row>
 161
 162           <row><entry><varname>vlan</varname></entry>
 163           <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>
 164
 165           <row><entry><varname>vti</varname></entry>
 166           <entry>An IPv4 over IPSec tunnel.</entry></row>
 167
 168           <row><entry><varname>vti6</varname></entry>
 169           <entry>An IPv6 over IPSec tunnel.</entry></row>
 170
 171           <row><entry><varname>vxlan</varname></entry>
 172           <entry>A virtual extensible LAN (vxlan), for connecting Cloud computing deployments.</entry></row>
 173
 174           <row><entry><varname>geneve</varname></entry>
 175           <entry>A GEneric NEtwork Virtualization Encapsulation (GENEVE) netdev driver.</entry></row>
 176
 177           <row><entry><varname>vrf</varname></entry>
 178           <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>
 179
 180           <row><entry><varname>vcan</varname></entry>
 181           <entry>The virtual CAN driver (vcan). Similar to the network loopback devices, vcan offers a virtual local CAN interface.</entry></row>
 182
 183         </tbody>
 184       </tgroup>
 185     </table>
 186
 187   </refsect1>
 188
 189   <refsect1>
 190     <title>[Match] Section Options</title>
 191
 192     <para>A virtual network device is only created if the
 193     <literal>[Match]</literal> section matches the current
 194     environment, or if the section is empty. The following keys are
 195     accepted:</para>
 196
 197     <variablelist class='network-directives'>
 198       <varlistentry>
 199         <term><varname>Host=</varname></term>
 200         <listitem>
 201           <para>Matches against the hostname or machine ID of the
 202           host. See <literal>ConditionHost=</literal> in
 203           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 204           for details.
 205           </para>
 206         </listitem>
 207       </varlistentry>
 208       <varlistentry>
 209         <term><varname>Virtualization=</varname></term>
 210         <listitem>
 211           <para>Checks whether the system is executed in a virtualized
 212           environment and optionally test whether it is a specific
 213           implementation. See
 214           <literal>ConditionVirtualization=</literal> in
 215           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 216           for details.
 217           </para>
 218         </listitem>
 219       </varlistentry>
 220       <varlistentry>
 221         <term><varname>KernelCommandLine=</varname></term>
 222         <listitem>
 223           <para>Checks whether a specific kernel command line option
 224           is set (or if prefixed with the exclamation mark unset). See
 225           <literal>ConditionKernelCommandLine=</literal> in
 226           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 227           for details.
 228           </para>
 229         </listitem>
 230       </varlistentry>
 231       <varlistentry>
 232         <term><varname>Architecture=</varname></term>
 233         <listitem>
 234           <para>Checks whether the system is running on a specific
 235           architecture. See <literal>ConditionArchitecture=</literal> in
 236           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 237           for details.
 238           </para>
 239         </listitem>
 240       </varlistentry>
 241     </variablelist>
 242
 243   </refsect1>
 244
 245   <refsect1>
 246     <title>[NetDev] Section Options</title>
 247
 248       <para>The <literal>[NetDev]</literal> section accepts the
 249       following keys:</para>
 250
 251       <variablelist class='network-directives'>
 252         <varlistentry>
 253           <term><varname>Description=</varname></term>
 254           <listitem>
 255             <para>A free-form description of the netdev.</para>
 256           </listitem>
 257         </varlistentry>
 258         <varlistentry>
 259           <term><varname>Name=</varname></term>
 260           <listitem>
 261             <para>The interface name used when creating the netdev.
 262             This option is compulsory.</para>
 263           </listitem>
 264         </varlistentry>
 265         <varlistentry>
 266           <term><varname>Kind=</varname></term>
 267           <listitem>
 268             <para>The netdev kind. This option is compulsory. See the
 269             <literal>Supported netdev kinds</literal> section for the
 270             valid keys.</para>
 271           </listitem>
 272         </varlistentry>
 273         <varlistentry>
 274           <term><varname>MTUBytes=</varname></term>
 275           <listitem>
 276             <para>The maximum transmission unit in bytes to set for
 277             the device. The usual suffixes K, M, G, are supported and
 278             are understood to the base of 1024. This key is not
 279             currently supported for <literal>tun</literal> or
 280             <literal>tap</literal> devices.
 281             </para>
 282           </listitem>
 283         </varlistentry>
 284         <varlistentry>
 285           <term><varname>MACAddress=</varname></term>
 286           <listitem>
 287             <para>The MAC address to use for the device. If none is
 288             given, one is generated based on the interface name and
 289             the
 290             <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
 291             This key is not currently supported for
 292             <literal>tun</literal> or <literal>tap</literal> devices.
 293             </para>
 294           </listitem>
 295         </varlistentry>
 296       </variablelist>
 297   </refsect1>
 298
 299     <refsect1>
 300     <title>[Bridge] Section Options</title>
 301
 302       <para>The <literal>[Bridge]</literal> section only applies for
 303       netdevs of kind <literal>bridge</literal>, and accepts the
 304       following keys:</para>
 305
 306       <variablelist class='network-directives'>
 307         <varlistentry>
 308           <term><varname>HelloTimeSec=</varname></term>
 309           <listitem>
 310             <para>HelloTimeSec specifies the number of seconds between two hello packets
 311             sent out by the root bridge and the designated bridges. Hello packets are
 312             used to communicate information about the topology throughout the entire
 313             bridged local area network.</para>
 314           </listitem>
 315         </varlistentry>
 316         <varlistentry>
 317           <term><varname>MaxAgeSec=</varname></term>
 318           <listitem>
 319             <para>MaxAgeSec specifies the number of seconds of maximum message age.
 320             If the last seen (received) hello packet is more than this number of
 321             seconds old, the bridge in question will start the takeover procedure
 322             in attempt to become the Root Bridge itself.</para>
 323           </listitem>
 324         </varlistentry>
 325         <varlistentry>
 326           <term><varname>ForwardDelaySec=</varname></term>
 327           <listitem>
 328             <para>ForwardDelaySec specifies the number of seconds spent in each
 329             of the Listening and Learning states before the Forwarding state is entered.</para>
 330           </listitem>
 331         </varlistentry>
 332         <varlistentry>
 333           <term><varname>AgeingTimeSec=</varname></term>
 334           <listitem>
 335             <para>This specifies the number of seconds a MAC Address will be kept in
 336             the forwarding database after having a packet received from this MAC Address.</para>
 337           </listitem>
 338         </varlistentry>
 339         <varlistentry>
 340           <term><varname>Priority=</varname></term>
 341           <listitem>
 342             <para>The priority of the bridge. An integer between 0 and 65535. A lower value
 343             means higher priority. The bridge having the lowest priority will be elected as root bridge.</para>
 344           </listitem>
 345         </varlistentry>
 346         <varlistentry>
 347           <term><varname>GroupForwardMask=</varname></term>
 348           <listitem>
 349             <para>A 16-bit bitmask represented as an integer which allows forwarding of link
 350             local frames with 802.1D reserved addresses (01:80:C2:00:00:0X). A logical AND
 351             is performed between the specified bitmask and the exponentiation of 2^X, the
 352             lower nibble of the last octet of the MAC address. For example, a value of 8
 353             would allow forwarding of frames addressed to 01:80:C2:00:00:03 (802.1X PAE).</para>
 354           </listitem>
 355         </varlistentry>
 356         <varlistentry>
 357           <term><varname>DefaultPVID=</varname></term>
 358           <listitem>
 359             <para>This specifies the default port VLAN ID of a newly attached bridge port.
 360             Set this to an integer in the range 1–4094 or <literal>none</literal> to disable the PVID.</para>
 361           </listitem>
 362         </varlistentry>
 363         <varlistentry>
 364           <term><varname>MulticastQuerier=</varname></term>
 365           <listitem>
 366             <para>A boolean. This setting controls the IFLA_BR_MCAST_QUERIER option in the kernel.
 367             If enabled, the kernel will send general ICMP queries from a zero source address.
 368             This feature should allow faster convergence on startup, but it causes some
 369             multicast-aware switches to misbehave and disrupt forwarding of multicast packets.
 370             When unset, the kernel's default setting applies.
 371             </para>
 372           </listitem>
 373         </varlistentry>
 374         <varlistentry>
 375           <term><varname>MulticastSnooping=</varname></term>
 376           <listitem>
 377             <para>A boolean. This setting controls the IFLA_BR_MCAST_SNOOPING option in the kernel.
 378             If enabled, IGMP snooping monitors the Internet Group Management Protocol (IGMP) traffic
 379             between hosts and multicast routers. When unset, the kernel's default setting applies.
 380             </para>
 381           </listitem>
 382         </varlistentry>
 383         <varlistentry>
 384           <term><varname>VLANFiltering=</varname></term>
 385           <listitem>
 386             <para>A boolean. This setting controls the IFLA_BR_VLAN_FILTERING option in the kernel.
 387             If enabled, the bridge will be started in VLAN-filtering mode. When unset, the kernel's
 388             default setting applies.
 389             </para>
 390           </listitem>
 391         </varlistentry>
 392           <varlistentry>
 393           <term><varname>STP=</varname></term>
 394           <listitem>
 395             <para>A boolean. This enables the bridge's Spanning Tree Protocol (STP). When unset,
 396             the kernel's default setting applies.
 397             </para>
 398           </listitem>
 399         </varlistentry>
 400       </variablelist>
 401   </refsect1>
 402
 403   <refsect1>
 404     <title>[VLAN] Section Options</title>
 405
 406       <para>The <literal>[VLAN]</literal> section only applies for
 407       netdevs of kind <literal>vlan</literal>, and accepts the
 408       following key:</para>
 409
 410       <variablelist class='network-directives'>
 411         <varlistentry>
 412           <term><varname>Id=</varname></term>
 413           <listitem>
 414             <para>The VLAN ID to use. An integer in the range 0–4094.
 415             This option is compulsory.</para>
 416           </listitem>
 417         </varlistentry>
 418         <varlistentry>
 419           <term><varname>GVRP=</varname></term>
 420           <listitem>
 421             <para>The Generic VLAN Registration Protocol (GVRP) is a protocol that
 422             allows automatic learning of VLANs on a network. A boolean. When unset,
 423             the kernel's default setting applies.</para>
 424           </listitem>
 425         </varlistentry>
 426         <varlistentry>
 427           <term><varname>MVRP=</varname></term>
 428           <listitem>
 429             <para>Multiple VLAN Registration Protocol (MVRP) formerly known as GARP VLAN
 430             Registration Protocol (GVRP) is a standards-based Layer 2 network protocol,
 431             for automatic configuration of VLAN information on switches. It was defined
 432             in the 802.1ak amendment to 802.1Q-2005. A boolean. When unset, the kernel's
 433             default setting applies.</para>
 434           </listitem>
 435         </varlistentry>
 436         <varlistentry>
 437           <term><varname>LooseBinding=</varname></term>
 438           <listitem>
 439             <para>The VLAN loose binding mode, in which only the operational state is passed
 440             from the parent to the associated VLANs, but the VLAN device state is not changed.
 441             A boolean. When unset, the kernel's default setting applies.</para>
 442           </listitem>
 443         </varlistentry>
 444         <varlistentry>
 445           <term><varname>ReorderHeader=</varname></term>
 446           <listitem>
 447             <para>The VLAN reorder header is set VLAN interfaces behave like physical interfaces.
 448             A boolean. When unset, the kernel's default setting applies.</para>
 449           </listitem>
 450         </varlistentry>
 451       </variablelist>
 452   </refsect1>
 453
 454   <refsect1>
 455     <title>[MACVLAN] Section Options</title>
 456
 457     <para>The <literal>[MACVLAN]</literal> section only applies for
 458     netdevs of kind <literal>macvlan</literal>, and accepts the
 459     following key:</para>
 460
 461     <variablelist class='network-directives'>
 462       <varlistentry>
 463         <term><varname>Mode=</varname></term>
 464         <listitem>
 465           <para>The MACVLAN mode to use. The supported options are
 466           <literal>private</literal>,
 467           <literal>vepa</literal>,
 468           <literal>bridge</literal>, and
 469           <literal>passthru</literal>.
 470           </para>
 471         </listitem>
 472       </varlistentry>
 473     </variablelist>
 474
 475   </refsect1>
 476
 477     <refsect1>
 478     <title>[MACVTAP] Section Options</title>
 479
 480     <para>The <literal>[MACVTAP]</literal> section applies for
 481     netdevs of kind <literal>macvtap</literal> and accepts the
 482     same key as <literal>[MACVLAN]</literal>.</para>
 483
 484     </refsect1>
 485
 486   <refsect1>
 487     <title>[IPVLAN] Section Options</title>
 488
 489     <para>The <literal>[IPVLAN]</literal> section only applies for
 490     netdevs of kind <literal>ipvlan</literal>, and accepts the
 491     following key:</para>
 492
 493     <variablelist class='network-directives'>
 494       <varlistentry>
 495         <term><varname>Mode=</varname></term>
 496           <listitem>
 497             <para>The IPVLAN mode to use. The supported options are
 498             <literal>L2</literal> and <literal>L3</literal>.
 499             </para>
 500           </listitem>
 501       </varlistentry>
 502     </variablelist>
 503
 504   </refsect1>
 505
 506   <refsect1>
 507     <title>[VXLAN] Section Options</title>
 508     <para>The <literal>[VXLAN]</literal> section only applies for
 509     netdevs of kind <literal>vxlan</literal>, and accepts the
 510     following keys:</para>
 511
 512     <variablelist class='network-directives'>
 513       <varlistentry>
 514         <term><varname>Id=</varname></term>
 515         <listitem>
 516           <para>The VXLAN ID to use.</para>
 517         </listitem>
 518       </varlistentry>
 519       <varlistentry>
 520         <term><varname>Remote=</varname></term>
 521         <listitem>
 522           <para>Configures destination multicast group IP address.</para>
 523         </listitem>
 524       </varlistentry>
 525       <varlistentry>
 526         <term><varname>Local=</varname></term>
 527         <listitem>
 528           <para>Configures local IP address.</para>
 529         </listitem>
 530       </varlistentry>
 531         <varlistentry>
 532         <term><varname>TOS=</varname></term>
 533         <listitem>
 534           <para>The Type Of Service byte value for a vxlan interface.</para>
 535         </listitem>
 536       </varlistentry>
 537       <varlistentry>
 538         <term><varname>TTL=</varname></term>
 539         <listitem>
 540           <para>A fixed Time To Live N on Virtual eXtensible Local
 541           Area Network packets. N is a number in the range 1–255. 0
 542           is a special value meaning that packets inherit the TTL
 543           value.</para>
 544         </listitem>
 545       </varlistentry>
 546       <varlistentry>
 547         <term><varname>MacLearning=</varname></term>
 548         <listitem>
 549           <para>A boolean. When true, enables dynamic MAC learning
 550           to discover remote MAC addresses.</para>
 551         </listitem>
 552       </varlistentry>
 553       <varlistentry>
 554         <term><varname>FDBAgeingSec=</varname></term>
 555         <listitem>
 556           <para>The lifetime of Forwarding Database entry learnt by
 557           the kernel, in seconds.</para>
 558         </listitem>
 559       </varlistentry>
 560       <varlistentry>
 561         <term><varname>MaximumFDBEntries=</varname></term>
 562         <listitem>
 563           <para>Configures maximum number of FDB entries.</para>
 564         </listitem>
 565       </varlistentry>
 566       <varlistentry>
 567         <term><varname>ReduceARPProxy=</varname></term>
 568         <listitem>
 569           <para>A boolean. When true, bridge-connected VXLAN tunnel
 570           endpoint answers ARP requests from the local bridge on behalf
 571           of remote Distributed Overlay Virtual Ethernet
 572           <ulink url="https://en.wikipedia.org/wiki/Distributed_Overlay_Virtual_Ethernet">
 573           (DVOE)</ulink> clients. Defaults to false.</para>
 574         </listitem>
 575       </varlistentry>
 576       <varlistentry>
 577         <term><varname>L2MissNotification=</varname></term>
 578         <listitem>
 579           <para>A boolean. When true, enables netlink LLADDR miss
 580           notifications.</para>
 581         </listitem>
 582       </varlistentry>
 583       <varlistentry>
 584         <term><varname>L3MissNotification=</varname></term>
 585         <listitem>
 586           <para>A boolean. When true, enables netlink IP address miss
 587           notifications.</para>
 588         </listitem>
 589       </varlistentry>
 590       <varlistentry>
 591         <term><varname>RouteShortCircuit=</varname></term>
 592         <listitem>
 593           <para>A boolean. When true, route short circuiting is turned
 594           on.</para>
 595         </listitem>
 596       </varlistentry>
 597       <varlistentry>
 598         <term><varname>UDPChecksum=</varname></term>
 599         <listitem>
 600           <para>A boolean. When true, transmitting UDP checksums when doing VXLAN/IPv4 is turned on.</para>
 601         </listitem>
 602       </varlistentry>
 603       <varlistentry>
 604         <term><varname>UDP6ZeroChecksumTx=</varname></term>
 605         <listitem>
 606           <para>A boolean. When true, sending zero checksums in VXLAN/IPv6 is turned on.</para>
 607         </listitem>
 608       </varlistentry>
 609       <varlistentry>
 610         <term><varname>UDP6ZeroChecksumRx=</varname></term>
 611         <listitem>
 612           <para>A boolean. When true, receiving zero checksums in VXLAN/IPv6 is turned on.</para>
 613         </listitem>
 614       </varlistentry>
 615       <varlistentry>
 616         <term><varname>RemoteChecksumTx=</varname></term>
 617         <listitem>
 618           <para>A boolean. When true, remote transmit checksum offload of VXLAN is turned on.</para>
 619         </listitem>
 620       </varlistentry>
 621       <varlistentry>
 622         <term><varname>RemoteChecksumRx=</varname></term>
 623         <listitem>
 624           <para>A boolean. When true, remote receive checksum offload in VXLAN is turned on.</para>
 625         </listitem>
 626       </varlistentry>
 627     <varlistentry>
 628       <term><varname>GroupPolicyExtension=</varname></term>
 629       <listitem>
 630         <para>A boolean. When true, it enables Group Policy VXLAN extension security label mechanism
 631         across network peers based on VXLAN. For details about the Group Policy VXLAN, see the
 632         <ulink url="https://tools.ietf.org/html/draft-smith-vxlan-group-policy">
 633         VXLAN Group Policy </ulink> document. Defaults to false.</para>
 634       </listitem>
 635     </varlistentry>
 636     <varlistentry>
 637       <term><varname>DestinationPort=</varname></term>
 638       <listitem>
 639         <para>Configures the default destination UDP port on a per-device basis.
 640         If destination port is not specified then Linux kernel default will be used.
 641         Set destination port 4789 to get the IANA assigned value. If not set or if the
 642         destination port is assigned the empty string the default port of 4789 is used.</para>
 643       </listitem>
 644     </varlistentry>
 645     <varlistentry>
 646       <term><varname>PortRange=</varname></term>
 647         <listitem>
 648           <para>Configures VXLAN port range. VXLAN bases source
 649           UDP port based on flow to help the receiver to be able
 650           to load balance based on outer header flow. It
 651           restricts the port range to the normal UDP local
 652           ports, and allows overriding via configuration.</para>
 653         </listitem>
 654       </varlistentry>
 655     <varlistentry>
 656       <term><varname>FlowLabel=</varname></term>
 657         <listitem>
 658           <para>Specifies the flow label to use in outgoing packets.
 659           The valid range is 0-1048575.
 660           </para>
 661         </listitem>
 662       </varlistentry>
 663     </variablelist>
 664   </refsect1>
 665   <refsect1>
 666     <title>[GENEVE] Section Options</title>
 667     <para>The <literal>[GENEVE]</literal> section only applies for
 668     netdevs of kind <literal>geneve</literal>, and accepts the
 669     following keys:</para>
 670
 671     <variablelist class='network-directives'>
 672       <varlistentry>
 673         <term><varname>Id=</varname></term>
 674         <listitem>
 675           <para>Specifies the Virtual Network Identifier (VNI) to use. Ranges [0-16777215].</para>
 676         </listitem>
 677       </varlistentry>
 678       <varlistentry>
 679         <term><varname>Remote=</varname></term>
 680         <listitem>
 681           <para>Specifies the unicast destination IP address to use in outgoing packets.</para>
 682         </listitem>
 683       </varlistentry>
 684       <varlistentry>
 685         <term><varname>TOS=</varname></term>
 686         <listitem>
 687           <para>Specifies the TOS value to use in outgoing packets. Ranges [1-255].</para>
 688         </listitem>
 689       </varlistentry>
 690       <varlistentry>
 691         <term><varname>TTL=</varname></term>
 692         <listitem>
 693           <para>Specifies the TTL value to use in outgoing packets. Ranges [1-255].</para>
 694         </listitem>
 695       </varlistentry>
 696       <varlistentry>
 697         <term><varname>UDPChecksum=</varname></term>
 698         <listitem>
 699           <para>A boolean. When true, specifies if UDP checksum is calculated for transmitted packets over IPv4.</para>
 700         </listitem>
 701       </varlistentry>
 702       <varlistentry>
 703         <term><varname>UDP6ZeroChecksumTx=</varname></term>
 704         <listitem>
 705           <para>A boolean. When true, skip UDP checksum calculation for transmitted packets over IPv6.</para>
 706         </listitem>
 707       </varlistentry>
 708       <varlistentry>
 709         <term><varname>UDP6ZeroChecksumRx=</varname></term>
 710         <listitem>
 711           <para>A boolean. When true, allows incoming UDP packets over IPv6 with zero checksum field.</para>
 712         </listitem>
 713       </varlistentry>
 714     <varlistentry>
 715       <term><varname>DestinationPort=</varname></term>
 716       <listitem>
 717         <para>Specifies destination port. Defaults to 6081. If not set or assigned the empty string, the default
 718         port of 6081 is used.</para>
 719       </listitem>
 720     </varlistentry>
 721     <varlistentry>
 722       <term><varname>FlowLabel=</varname></term>
 723         <listitem>
 724           <para>Specifies the flow label to use in outgoing packets.</para>
 725         </listitem>
 726       </varlistentry>
 727     </variablelist>
 728   </refsect1>
 729   <refsect1>
 730     <title>[Tunnel] Section Options</title>
 731
 732     <para>The <literal>[Tunnel]</literal> section only applies for
 733     netdevs of kind
 734     <literal>ipip</literal>,
 735     <literal>sit</literal>,
 736     <literal>gre</literal>,
 737     <literal>gretap</literal>,
 738     <literal>ip6gre</literal>,
 739     <literal>ip6gretap</literal>,
 740     <literal>vti</literal>,
 741     <literal>vti6</literal>, and
 742     <literal>ip6tnl</literal> and accepts
 743     the following keys:</para>
 744
 745     <variablelist class='network-directives'>
 746       <varlistentry>
 747         <term><varname>Local=</varname></term>
 748         <listitem>
 749           <para>A static local address for tunneled packets. It must
 750           be an address on another interface of this host.</para>
 751         </listitem>
 752       </varlistentry>
 753       <varlistentry>
 754         <term><varname>Remote=</varname></term>
 755         <listitem>
 756           <para>The remote endpoint of the tunnel.</para>
 757         </listitem>
 758       </varlistentry>
 759       <varlistentry>
 760         <term><varname>TOS=</varname></term>
 761         <listitem>
 762           <para>The Type Of Service byte value for a tunnel interface.
 763           For details about the TOS, see the
 764           <ulink url="http://tools.ietf.org/html/rfc1349"> Type of
 765           Service in the Internet Protocol Suite </ulink> document.
 766           </para>
 767         </listitem>
 768       </varlistentry>
 769       <varlistentry>
 770         <term><varname>TTL=</varname></term>
 771         <listitem>
 772           <para>A fixed Time To Live N on tunneled packets. N is a
 773           number in the range 1–255. 0 is a special value meaning that
 774           packets inherit the TTL value. The default value for IPv4
 775           tunnels is: inherit. The default value for IPv6 tunnels is
 776           64.</para>
 777         </listitem>
 778       </varlistentry>
 779       <varlistentry>
 780         <term><varname>DiscoverPathMTU=</varname></term>
 781         <listitem>
 782           <para>A boolean. When true, enables Path MTU Discovery on
 783           the tunnel.</para>
 784         </listitem>
 785       </varlistentry>
 786       <varlistentry>
 787         <term><varname>IPv6FlowLabel=</varname></term>
 788         <listitem>
 789           <para>Configures the 20-bit flow label (see <ulink url="https://tools.ietf.org/html/rfc6437">
 790           RFC 6437</ulink>) field in the IPv6 header (see <ulink url="https://tools.ietf.org/html/rfc2460">
 791           RFC 2460</ulink>), which is used by a node to label packets of a flow.
 792           It is only used for IPv6 tunnels.
 793           A flow label of zero is used to indicate packets that have
 794           not been labeled.
 795           It can be configured to a value in the range 0–0xFFFFF, or be
 796           set to <literal>inherit</literal>, in which case the original flowlabel is used.</para>
 797         </listitem>
 798       </varlistentry>
 799       <varlistentry>
 800         <term><varname>CopyDSCP=</varname></term>
 801         <listitem>
 802           <para>A boolean. When true, the Differentiated Service Code
 803           Point (DSCP) field will be copied to the inner header from
 804           outer header during the decapsulation of an IPv6 tunnel
 805           packet. DSCP is a field in an IP packet that enables different
 806           levels of service to be assigned to network traffic.
 807           Defaults to <literal>no</literal>.
 808           </para>
 809         </listitem>
 810       </varlistentry>
 811       <varlistentry>
 812         <term><varname>EncapsulationLimit=</varname></term>
 813         <listitem>
 814           <para>The Tunnel Encapsulation Limit option specifies how many additional
 815           levels of encapsulation are permitted to be prepended to the packet.
 816           For example, a Tunnel Encapsulation Limit option containing a limit
 817           value of zero means that a packet carrying that option may not enter
 818           another tunnel before exiting the current tunnel.
 819           (see <ulink url="https://tools.ietf.org/html/rfc2473#section-4.1.1"> RFC 2473</ulink>).
 820           The valid range is 0–255 and <literal>none</literal>. Defaults to 4.
 821         </para>
 822         </listitem>
 823       </varlistentry>
 824       <varlistentry>
 825         <term><varname>Key=</varname></term>
 826         <listitem>
 827           <para>The <varname>Key=</varname> parameter specifies the same key to use in
 828           both directions (<varname>InputKey=</varname> and <varname>OutputKey=</varname>).
 829           The <varname>Key=</varname> is either a number or an IPv4 address-like dotted quad.
 830           It is used as mark-configured SAD/SPD entry as part of the lookup key (both in data
 831           and control path) in ip xfrm (framework used to implement IPsec protocol).
 832           See <ulink url="http://man7.org/linux/man-pages/man8/ip-xfrm.8.html">
 833           ip-xfrm — transform configuration</ulink> for details. It is only used for VTI/VTI6
 834           tunnels.</para>
 835         </listitem>
 836       </varlistentry>
 837       <varlistentry>
 838         <term><varname>InputKey=</varname></term>
 839         <listitem>
 840           <para>The <varname>InputKey=</varname> parameter specifies the key to use for input.
 841           The format is same as <varname>Key=</varname>. It is only used for VTI/VTI6 tunnels.</para>
 842         </listitem>
 843       </varlistentry>
 844       <varlistentry>
 845         <term><varname>OutputKey=</varname></term>
 846         <listitem>
 847           <para>The <varname>OutputKey=</varname> parameter specifies the key to use for output.
 848           The format is same as <varname>Key=</varname>. It is only used for VTI/VTI6 tunnels.</para>
 849         </listitem>
 850       </varlistentry>
 851       <varlistentry>
 852         <term><varname>Mode=</varname></term>
 853         <listitem>
 854           <para>An <literal>ip6tnl</literal> tunnel can be in one of three
 855           modes
 856           <literal>ip6ip6</literal> for IPv6 over IPv6,
 857           <literal>ipip6</literal> for IPv4 over IPv6 or
 858           <literal>any</literal> for either.
 859           </para>
 860         </listitem>
 861       </varlistentry>
 862       <varlistentry>
 863         <term><varname>Independent=</varname></term>
 864         <listitem>
 865           <para>A boolean. When true tunnel does not require .network file. Created as "tunnel@NONE".
 866           Defaults to <literal>false</literal>.
 867           </para>
 868         </listitem>
 869       </varlistentry>
 870     </variablelist>
 871   </refsect1>
 872   <refsect1>
 873     <title>[Peer] Section Options</title>
 874
 875       <para>The <literal>[Peer]</literal> section only applies for
 876       netdevs of kind <literal>veth</literal> and accepts the
 877       following keys:</para>
 878
 879       <variablelist class='network-directives'>
 880         <varlistentry>
 881           <term><varname>Name=</varname></term>
 882           <listitem>
 883             <para>The interface name used when creating the netdev.
 884             This option is compulsory.</para>
 885           </listitem>
 886         </varlistentry>
 887         <varlistentry>
 888           <term><varname>MACAddress=</varname></term>
 889           <listitem>
 890             <para>The peer MACAddress, if not set, it is generated in
 891             the same way as the MAC address of the main
 892             interface.</para>
 893           </listitem>
 894         </varlistentry>
 895       </variablelist>
 896   </refsect1>
 897   <refsect1>
 898     <title>[Tun] Section Options</title>
 899
 900     <para>The <literal>[Tun]</literal> section only applies for
 901     netdevs of kind <literal>tun</literal>, and accepts the following
 902     keys:</para>
 903
 904     <variablelist class='network-directives'>
 905       <varlistentry>
 906         <term><varname>OneQueue=</varname></term>
 907         <listitem><para>Takes a boolean argument. Configures whether
 908         all packets are queued at the device (enabled), or a fixed
 909         number of packets are queued at the device and the rest at the
 910         <literal>qdisc</literal>. Defaults to
 911         <literal>no</literal>.</para>
 912         </listitem>
 913       </varlistentry>
 914       <varlistentry>
 915         <term><varname>MultiQueue=</varname></term>
 916         <listitem><para>Takes a boolean argument. Configures whether
 917         to use multiple file descriptors (queues) to parallelize
 918         packets sending and receiving. Defaults to
 919         <literal>no</literal>.</para>
 920         </listitem>
 921       </varlistentry>
 922       <varlistentry>
 923         <term><varname>PacketInfo=</varname></term>
 924         <listitem><para>Takes a boolean argument. Configures whether
 925         packets should be prepended with four extra bytes (two flag
 926         bytes and two protocol bytes). If disabled, it indicates that
 927         the packets will be pure IP packets. Defaults to
 928         <literal>no</literal>.</para>
 929         </listitem>
 930       </varlistentry>
 931       <varlistentry>
 932         <term><varname>VNetHeader=</varname></term>
 933         <listitem><para>Takes a boolean argument. Configures
 934         IFF_VNET_HDR flag for a tap device. It allows sending
 935         and receiving larger Generic Segmentation Offload (GSO)
 936         packets. This may increase throughput significantly.
 937         Defaults to
 938         <literal>no</literal>.</para>
 939         </listitem>
 940       </varlistentry>
 941       <varlistentry>
 942         <term><varname>User=</varname></term>
 943         <listitem><para>User to grant access to the
 944         <filename>/dev/net/tun</filename> device.</para>
 945         </listitem>
 946       </varlistentry>
 947       <varlistentry>
 948         <term><varname>Group=</varname></term>
 949         <listitem><para>Group to grant access to the
 950         <filename>/dev/net/tun</filename> device.</para>
 951         </listitem>
 952       </varlistentry>
 953
 954     </variablelist>
 955
 956   </refsect1>
 957
 958   <refsect1>
 959     <title>[Tap] Section Options</title>
 960
 961     <para>The <literal>[Tap]</literal> section only applies for
 962     netdevs of kind <literal>tap</literal>, and accepts the same keys
 963     as the <literal>[Tun]</literal> section.</para>
 964   </refsect1>
 965
 966   <refsect1>
 967     <title>[Bond] Section Options</title>
 968
 969     <para>The <literal>[Bond]</literal> section accepts the following
 970     key:</para>
 971
 972     <variablelist class='network-directives'>
 973       <varlistentry>
 974         <term><varname>Mode=</varname></term>
 975         <listitem>
 976           <para>Specifies one of the bonding policies. The default is
 977           <literal>balance-rr</literal> (round robin). Possible values are
 978           <literal>balance-rr</literal>,
 979           <literal>active-backup</literal>,
 980           <literal>balance-xor</literal>,
 981           <literal>broadcast</literal>,
 982           <literal>802.3ad</literal>,
 983           <literal>balance-tlb</literal>, and
 984           <literal>balance-alb</literal>.
 985           </para>
 986         </listitem>
 987       </varlistentry>
 988
 989       <varlistentry>
 990         <term><varname>TransmitHashPolicy=</varname></term>
 991         <listitem>
 992           <para>Selects the transmit hash policy to use for slave
 993           selection in balance-xor, 802.3ad, and tlb modes. Possible
 994           values are
 995           <literal>layer2</literal>,
 996           <literal>layer3+4</literal>,
 997           <literal>layer2+3</literal>,
 998           <literal>encap2+3</literal>, and
 999           <literal>encap3+4</literal>.
1000           </para>
1001         </listitem>
1002       </varlistentry>
1003
1004       <varlistentry>
1005         <term><varname>LACPTransmitRate=</varname></term>
1006         <listitem>
1007           <para>Specifies the rate with which link partner transmits
1008           Link Aggregation Control Protocol Data Unit packets in
1009           802.3ad mode. Possible values are <literal>slow</literal>,
1010           which requests partner to transmit LACPDUs every 30 seconds,
1011           and <literal>fast</literal>, which requests partner to
1012           transmit LACPDUs every second. The default value is
1013           <literal>slow</literal>.</para>
1014         </listitem>
1015       </varlistentry>
1016
1017       <varlistentry>
1018         <term><varname>MIIMonitorSec=</varname></term>
1019         <listitem>
1020           <para>Specifies the frequency that Media Independent
1021           Interface link monitoring will occur. A value of zero
1022           disables MII link monitoring. This value is rounded down to
1023           the nearest millisecond. The default value is 0.</para>
1024         </listitem>
1025       </varlistentry>
1026
1027       <varlistentry>
1028         <term><varname>UpDelaySec=</varname></term>
1029         <listitem>
1030           <para>Specifies the delay before a link is enabled after a
1031           link up status has been detected. This value is rounded down
1032           to a multiple of MIIMonitorSec. The default value is
1033           0.</para>
1034         </listitem>
1035       </varlistentry>
1036
1037       <varlistentry>
1038         <term><varname>DownDelaySec=</varname></term>
1039         <listitem>
1040           <para>Specifies the delay before a link is disabled after a
1041           link down status has been detected. This value is rounded
1042           down to a multiple of MIIMonitorSec. The default value is
1043           0.</para>
1044         </listitem>
1045       </varlistentry>
1046
1047       <varlistentry>
1048         <term><varname>LearnPacketIntervalSec=</varname></term>
1049         <listitem>
1050           <para>Specifies the number of seconds between instances where the bonding
1051           driver sends learning packets to each slave peer switch.
1052           The valid range is 1–0x7fffffff; the default value is 1. This option
1053           has an effect only for the balance-tlb and balance-alb modes.</para>
1054         </listitem>
1055       </varlistentry>
1056
1057       <varlistentry>
1058         <term><varname>AdSelect=</varname></term>
1059         <listitem>
1060           <para>Specifies the 802.3ad aggregation selection logic to use. Possible values are
1061           <literal>stable</literal>,
1062           <literal>bandwidth</literal> and
1063           <literal>count</literal>.
1064           </para>
1065         </listitem>
1066       </varlistentry>
1067
1068       <varlistentry>
1069         <term><varname>FailOverMACPolicy=</varname></term>
1070         <listitem>
1071           <para>Specifies whether the active-backup mode should set all slaves to
1072           the same MAC address at the time of enslavement or, when enabled, to perform special handling of the
1073           bond's MAC address in accordance with the selected policy. The default policy is none.
1074           Possible values are
1075           <literal>none</literal>,
1076           <literal>active</literal> and
1077           <literal>follow</literal>.
1078           </para>
1079         </listitem>
1080       </varlistentry>
1081
1082       <varlistentry>
1083         <term><varname>ARPValidate=</varname></term>
1084         <listitem>
1085           <para>Specifies whether or not ARP probes and replies should be
1086           validated in any mode that supports ARP monitoring, or whether
1087           non-ARP traffic should be filtered (disregarded) for link
1088           monitoring purposes. Possible values are
1089           <literal>none</literal>,
1090           <literal>active</literal>,
1091           <literal>backup</literal> and
1092           <literal>all</literal>.
1093           </para>
1094         </listitem>
1095       </varlistentry>
1096
1097       <varlistentry>
1098         <term><varname>ARPIntervalSec=</varname></term>
1099         <listitem>
1100           <para>Specifies the ARP link monitoring frequency in milliseconds.
1101           A value of 0 disables ARP monitoring. The default value is 0.
1102           </para>
1103         </listitem>
1104       </varlistentry>
1105
1106       <varlistentry>
1107         <term><varname>ARPIPTargets=</varname></term>
1108         <listitem>
1109           <para>Specifies the IP addresses to use as ARP monitoring peers when
1110           ARPIntervalSec is greater than 0. These are the targets of the ARP request
1111           sent to determine the health of the link to the targets.
1112           Specify these values in IPv4 dotted decimal format. At least one IP
1113           address must be given for ARP monitoring to function. The
1114           maximum number of targets that can be specified is 16. The
1115           default value is no IP addresses.
1116           </para>
1117         </listitem>
1118       </varlistentry>
1119
1120       <varlistentry>
1121         <term><varname>ARPAllTargets=</varname></term>
1122         <listitem>
1123           <para>Specifies the quantity of ARPIPTargets that must be reachable
1124           in order for the ARP monitor to consider a slave as being up.
1125           This option affects only active-backup mode for slaves with
1126           ARPValidate enabled. Possible values are
1127           <literal>any</literal> and
1128           <literal>all</literal>.
1129           </para>
1130         </listitem>
1131       </varlistentry>
1132
1133       <varlistentry>
1134         <term><varname>PrimaryReselectPolicy=</varname></term>
1135         <listitem>
1136           <para>Specifies the reselection policy for the primary slave.  This
1137           affects how the primary slave is chosen to become the active slave
1138           when failure of the active slave or recovery of the primary slave
1139           occurs. This option is designed to prevent flip-flopping between
1140           the primary slave and other slaves.  Possible values are
1141           <literal>always</literal>,
1142           <literal>better</literal> and
1143           <literal>failure</literal>.
1144           </para>
1145         </listitem>
1146       </varlistentry>
1147
1148       <varlistentry>
1149         <term><varname>ResendIGMP=</varname></term>
1150         <listitem>
1151           <para>Specifies the number of IGMP membership reports to be issued after
1152           a failover event. One membership report is issued immediately after
1153           the failover, subsequent packets are sent in each 200ms interval.
1154           The valid range is 0–255. Defaults to 1. A value of 0
1155           prevents the IGMP membership report from being issued in response
1156           to the failover event.
1157           </para>
1158         </listitem>
1159       </varlistentry>
1160
1161       <varlistentry>
1162         <term><varname>PacketsPerSlave=</varname></term>
1163         <listitem>
1164           <para>Specify the number of packets to transmit through a slave before
1165             moving to the next one. When set to 0, then a slave is chosen at
1166             random. The valid range is 0–65535. Defaults to 1. This option
1167             only has effect when in balance-rr mode.
1168           </para>
1169         </listitem>
1170       </varlistentry>
1171
1172       <varlistentry>
1173         <term><varname>GratuitousARP=</varname></term>
1174         <listitem>
1175           <para>Specify the number of peer notifications (gratuitous ARPs and
1176             unsolicited IPv6 Neighbor Advertisements) to be issued after a
1177             failover event.  As soon as the link is up on the new slave,
1178             a peer notification is sent on the  bonding device and each
1179             VLAN sub-device.  This is repeated at each link monitor interval
1180             (ARPIntervalSec or MIIMonitorSec, whichever is active) if the number is
1181             greater than 1. The valid range is 0–255. The default value is 1.
1182             These options affect only the active-backup mode.
1183           </para>
1184         </listitem>
1185       </varlistentry>
1186
1187       <varlistentry>
1188         <term><varname>AllSlavesActive=</varname></term>
1189         <listitem>
1190           <para>A boolean. Specifies that duplicate frames (received on inactive ports)
1191           should be dropped when false, or delivered when true. Normally, bonding will drop
1192           duplicate frames (received on inactive ports), which is desirable for
1193           most users. But there are some times it is nice to allow duplicate
1194           frames to be delivered. The default value is false (drop duplicate frames
1195           received on inactive ports).
1196           </para>
1197         </listitem>
1198       </varlistentry>
1199
1200       <varlistentry>
1201         <term><varname>MinLinks=</varname></term>
1202         <listitem>
1203           <para>Specifies the minimum number of links that must be active before
1204           asserting carrier. The default value is 0.
1205           </para>
1206         </listitem>
1207       </varlistentry>
1208     </variablelist>
1209
1210     <para>For more detail information see
1211     <ulink url="https://www.kernel.org/doc/Documentation/networking/bonding.txt">
1212     Linux Ethernet Bonding Driver HOWTO</ulink></para>
1213
1214   </refsect1>
1215
1216   <refsect1>
1217     <title>Example</title>
1218     <example>
1219       <title>/etc/systemd/network/25-bridge.netdev</title>
1220
1221       <programlisting>[NetDev]
1222 Name=bridge0
1223 Kind=bridge</programlisting>
1224     </example>
1225
1226     <example>
1227       <title>/etc/systemd/network/25-vlan1.netdev</title>
1228
1229       <programlisting>[Match]
1230 Virtualization=no
1231
1232 [NetDev]
1233 Name=vlan1
1234 Kind=vlan
1235
1236 [VLAN]
1237 Id=1</programlisting>
1238     </example>
1239     <example>
1240       <title>/etc/systemd/network/25-ipip.netdev</title>
1241       <programlisting>[NetDev]
1242 Name=ipip-tun
1243 Kind=ipip
1244 MTUBytes=1480
1245
1246 [Tunnel]
1247 Local=192.168.223.238
1248 Remote=192.169.224.239
1249 TTL=64</programlisting>
1250     </example>
1251     <example>
1252       <title>/etc/systemd/network/25-tap.netdev</title>
1253       <programlisting>[NetDev]
1254 Name=tap-test
1255 Kind=tap
1256
1257 [Tap]
1258 MultiQueue=true
1259 PacketInfo=true</programlisting> </example>
1260
1261     <example>
1262       <title>/etc/systemd/network/25-sit.netdev</title>
1263       <programlisting>[NetDev]
1264 Name=sit-tun
1265 Kind=sit
1266 MTUBytes=1480
1267
1268 [Tunnel]
1269 Local=10.65.223.238
1270 Remote=10.65.223.239</programlisting>
1271     </example>
1272
1273     <example>
1274       <title>/etc/systemd/network/25-gre.netdev</title>
1275       <programlisting>[NetDev]
1276 Name=gre-tun
1277 Kind=gre
1278 MTUBytes=1480
1279
1280 [Tunnel]
1281 Local=10.65.223.238
1282 Remote=10.65.223.239</programlisting>
1283     </example>
1284
1285     <example>
1286       <title>/etc/systemd/network/25-vti.netdev</title>
1287
1288       <programlisting>[NetDev]
1289 Name=vti-tun
1290 Kind=vti
1291 MTUBytes=1480
1292
1293 [Tunnel]
1294 Local=10.65.223.238
1295 Remote=10.65.223.239</programlisting>
1296     </example>
1297
1298     <example>
1299       <title>/etc/systemd/network/25-veth.netdev</title>
1300       <programlisting>[NetDev]
1301 Name=veth-test
1302 Kind=veth
1303
1304 [Peer]
1305 Name=veth-peer</programlisting>
1306     </example>
1307
1308     <example>
1309       <title>/etc/systemd/network/25-bond.netdev</title>
1310       <programlisting>[NetDev]
1311 Name=bond1
1312 Kind=bond
1313
1314 [Bond]
1315 Mode=802.3ad
1316 TransmitHashPolicy=layer3+4
1317 MIIMonitorSec=1s
1318 LACPTransmitRate=fast
1319 </programlisting>
1320     </example>
1321
1322     <example>
1323       <title>/etc/systemd/network/25-dummy.netdev</title>
1324       <programlisting>[NetDev]
1325 Name=dummy-test
1326 Kind=dummy
1327 MACAddress=12:34:56:78:9a:bc</programlisting>
1328     </example>
1329     <example>
1330       <title>/etc/systemd/network/25-vrf.netdev</title>
1331       <para>Create a VRF interface with table 42.</para>
1332       <programlisting>[NetDev]
1333 Name=vrf-test
1334 Kind=vrf
1335
1336 [VRF]
1337 Table=42</programlisting>
1338     </example>
1339
1340     <example>
1341       <title>/etc/systemd/network/25-macvtap.netdev</title>
1342       <para>Create a MacVTap device.</para>
1343       <programlisting>[NetDev]
1344 Name=macvtap-test
1345 Kind=macvtap
1346       </programlisting>
1347     </example>
1348   </refsect1>
1349   <refsect1>
1350     <title>See Also</title>
1351     <para>
1352       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1353       <citerefentry><refentrytitle>systemd-networkd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
1354       <citerefentry><refentrytitle>systemd.link</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1355       <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>
1356     </para>
1357   </refsect1>
1358
1359 </refentry>