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>GroupForwardMask=</varname></term>
 346           <listitem>
 347             <para>A 16-bit bitmask represented as an integer which allows forwarding of link
 348             local frames with 802.1D reserved addresses (01:80:C2:00:00:0X). A logical AND
 349             is performed between the specified bitmask and the exponentiation of 2^X, the
 350             lower nibble of the last octet of the MAC address. For example, a value of 8
 351             would allow forwarding of frames addressed to 01:80:C2:00:00:03 (802.1X PAE).</para>
 352           </listitem>
 353         </varlistentry>
 354         <varlistentry>
 355           <term><varname>DefaultPVID=</varname></term>
 356           <listitem>
 357             <para>This specifies the default port VLAN ID of a newly attached bridge port.
 358             Set this to an integer in the range 1–4094 or <literal>none</literal> to disable the PVID.</para>
 359           </listitem>
 360         </varlistentry>
 361         <varlistentry>
 362           <term><varname>MulticastQuerier=</varname></term>
 363           <listitem>
 364             <para>A boolean. This setting controls the IFLA_BR_MCAST_QUERIER option in the kernel.
 365             If enabled, the kernel will send general ICMP queries from a zero source address.
 366             This feature should allow faster convergence on startup, but it causes some
 367             multicast-aware switches to misbehave and disrupt forwarding of multicast packets.
 368             When unset, the kernel's default setting applies.
 369             </para>
 370           </listitem>
 371         </varlistentry>
 372         <varlistentry>
 373           <term><varname>MulticastSnooping=</varname></term>
 374           <listitem>
 375             <para>A boolean. This setting controls the IFLA_BR_MCAST_SNOOPING option in the kernel.
 376             If enabled, IGMP snooping monitors the Internet Group Management Protocol (IGMP) traffic
 377             between hosts and multicast routers. When unset, the kernel's default setting applies.
 378             </para>
 379           </listitem>
 380         </varlistentry>
 381         <varlistentry>
 382           <term><varname>VLANFiltering=</varname></term>
 383           <listitem>
 384             <para>A boolean. This setting controls the IFLA_BR_VLAN_FILTERING option in the kernel.
 385             If enabled, the bridge will be started in VLAN-filtering mode. When unset, the kernel's
 386             default setting applies.
 387             </para>
 388           </listitem>
 389         </varlistentry>
 390           <varlistentry>
 391           <term><varname>STP=</varname></term>
 392           <listitem>
 393             <para>A boolean. This enables the bridge's Spanning Tree Protocol (STP). When unset,
 394             the kernel's default setting applies.
 395             </para>
 396           </listitem>
 397         </varlistentry>
 398       </variablelist>
 399   </refsect1>
 400
 401   <refsect1>
 402     <title>[VLAN] Section Options</title>
 403
 404       <para>The <literal>[VLAN]</literal> section only applies for
 405       netdevs of kind <literal>vlan</literal>, and accepts the
 406       following key:</para>
 407
 408       <variablelist class='network-directives'>
 409         <varlistentry>
 410           <term><varname>Id=</varname></term>
 411           <listitem>
 412             <para>The VLAN ID to use. An integer in the range 0–4094.
 413             This option is compulsory.</para>
 414           </listitem>
 415         </varlistentry>
 416         <varlistentry>
 417           <term><varname>GVRP=</varname></term>
 418           <listitem>
 419             <para>The Generic VLAN Registration Protocol (GVRP) is a protocol that
 420             allows automatic learning of VLANs on a network. A boolean. When unset,
 421             the kernel's default setting applies.</para>
 422           </listitem>
 423         </varlistentry>
 424         <varlistentry>
 425           <term><varname>MVRP=</varname></term>
 426           <listitem>
 427             <para>Multiple VLAN Registration Protocol (MVRP) formerly known as GARP VLAN
 428             Registration Protocol (GVRP) is a standards-based Layer 2 network protocol,
 429             for automatic configuration of VLAN information on switches. It was defined
 430             in the 802.1ak amendment to 802.1Q-2005. A boolean. When unset, the kernel's
 431             default setting applies.</para>
 432           </listitem>
 433         </varlistentry>
 434         <varlistentry>
 435           <term><varname>LooseBinding=</varname></term>
 436           <listitem>
 437             <para>The VLAN loose binding mode, in which only the operational state is passed
 438             from the parent to the associated VLANs, but the VLAN device state is not changed.
 439             A boolean. When unset, the kernel's default setting applies.</para>
 440           </listitem>
 441         </varlistentry>
 442         <varlistentry>
 443           <term><varname>ReorderHeader=</varname></term>
 444           <listitem>
 445             <para>The VLAN reorder header is set VLAN interfaces behave like physical interfaces.
 446             A boolean. When unset, the kernel's default setting applies.</para>
 447           </listitem>
 448         </varlistentry>
 449       </variablelist>
 450   </refsect1>
 451
 452   <refsect1>
 453     <title>[MACVLAN] Section Options</title>
 454
 455     <para>The <literal>[MACVLAN]</literal> section only applies for
 456     netdevs of kind <literal>macvlan</literal>, and accepts the
 457     following key:</para>
 458
 459     <variablelist class='network-directives'>
 460       <varlistentry>
 461         <term><varname>Mode=</varname></term>
 462         <listitem>
 463           <para>The MACVLAN mode to use. The supported options are
 464           <literal>private</literal>,
 465           <literal>vepa</literal>,
 466           <literal>bridge</literal>, and
 467           <literal>passthru</literal>.
 468           </para>
 469         </listitem>
 470       </varlistentry>
 471     </variablelist>
 472
 473   </refsect1>
 474
 475     <refsect1>
 476     <title>[MACVTAP] Section Options</title>
 477
 478     <para>The <literal>[MACVTAP]</literal> section applies for
 479     netdevs of kind <literal>macvtap</literal> and accepts the
 480     same key as <literal>[MACVLAN]</literal>.</para>
 481
 482     </refsect1>
 483
 484   <refsect1>
 485     <title>[IPVLAN] Section Options</title>
 486
 487     <para>The <literal>[IPVLAN]</literal> section only applies for
 488     netdevs of kind <literal>ipvlan</literal>, and accepts the
 489     following key:</para>
 490
 491     <variablelist class='network-directives'>
 492       <varlistentry>
 493         <term><varname>Mode=</varname></term>
 494           <listitem>
 495             <para>The IPVLAN mode to use. The supported options are
 496             <literal>L2</literal> and <literal>L3</literal>.
 497             </para>
 498           </listitem>
 499       </varlistentry>
 500     </variablelist>
 501
 502   </refsect1>
 503
 504   <refsect1>
 505     <title>[VXLAN] Section Options</title>
 506     <para>The <literal>[VXLAN]</literal> section only applies for
 507     netdevs of kind <literal>vxlan</literal>, and accepts the
 508     following keys:</para>
 509
 510     <variablelist class='network-directives'>
 511       <varlistentry>
 512         <term><varname>Id=</varname></term>
 513         <listitem>
 514           <para>The VXLAN ID to use.</para>
 515         </listitem>
 516       </varlistentry>
 517       <varlistentry>
 518         <term><varname>Remote=</varname></term>
 519         <listitem>
 520           <para>Configures destination multicast group IP address.</para>
 521         </listitem>
 522       </varlistentry>
 523       <varlistentry>
 524         <term><varname>Local=</varname></term>
 525         <listitem>
 526           <para>Configures local IP address.</para>
 527         </listitem>
 528       </varlistentry>
 529         <varlistentry>
 530         <term><varname>TOS=</varname></term>
 531         <listitem>
 532           <para>The Type Of Service byte value for a vxlan interface.</para>
 533         </listitem>
 534       </varlistentry>
 535       <varlistentry>
 536         <term><varname>TTL=</varname></term>
 537         <listitem>
 538           <para>A fixed Time To Live N on Virtual eXtensible Local
 539           Area Network packets. N is a number in the range 1–255. 0
 540           is a special value meaning that packets inherit the TTL
 541           value.</para>
 542         </listitem>
 543       </varlistentry>
 544       <varlistentry>
 545         <term><varname>MacLearning=</varname></term>
 546         <listitem>
 547           <para>A boolean. When true, enables dynamic MAC learning
 548           to discover remote MAC addresses.</para>
 549         </listitem>
 550       </varlistentry>
 551       <varlistentry>
 552         <term><varname>FDBAgeingSec=</varname></term>
 553         <listitem>
 554           <para>The lifetime of Forwarding Database entry learnt by
 555           the kernel, in seconds.</para>
 556         </listitem>
 557       </varlistentry>
 558       <varlistentry>
 559         <term><varname>MaximumFDBEntries=</varname></term>
 560         <listitem>
 561           <para>Configures maximum number of FDB entries.</para>
 562         </listitem>
 563       </varlistentry>
 564       <varlistentry>
 565         <term><varname>ReduceARPProxy=</varname></term>
 566         <listitem>
 567           <para>A boolean. When true, bridge-connected VXLAN tunnel
 568           endpoint answers ARP requests from the local bridge on behalf
 569           of remote Distributed Overlay Virtual Ethernet
 570           <ulink url="https://en.wikipedia.org/wiki/Distributed_Overlay_Virtual_Ethernet">
 571           (DVOE)</ulink> clients. Defaults to false.</para>
 572         </listitem>
 573       </varlistentry>
 574       <varlistentry>
 575         <term><varname>L2MissNotification=</varname></term>
 576         <listitem>
 577           <para>A boolean. When true, enables netlink LLADDR miss
 578           notifications.</para>
 579         </listitem>
 580       </varlistentry>
 581       <varlistentry>
 582         <term><varname>L3MissNotification=</varname></term>
 583         <listitem>
 584           <para>A boolean. When true, enables netlink IP address miss
 585           notifications.</para>
 586         </listitem>
 587       </varlistentry>
 588       <varlistentry>
 589         <term><varname>RouteShortCircuit=</varname></term>
 590         <listitem>
 591           <para>A boolean. When true, route short circuiting is turned
 592           on.</para>
 593         </listitem>
 594       </varlistentry>
 595       <varlistentry>
 596         <term><varname>UDPChecksum=</varname></term>
 597         <listitem>
 598           <para>A boolean. When true, transmitting UDP checksums when doing VXLAN/IPv4 is turned on.</para>
 599         </listitem>
 600       </varlistentry>
 601       <varlistentry>
 602         <term><varname>UDP6ZeroChecksumTx=</varname></term>
 603         <listitem>
 604           <para>A boolean. When true, sending zero checksums in VXLAN/IPv6 is turned on.</para>
 605         </listitem>
 606       </varlistentry>
 607       <varlistentry>
 608         <term><varname>UDP6ZeroChecksumRx=</varname></term>
 609         <listitem>
 610           <para>A boolean. When true, receiving zero checksums in VXLAN/IPv6 is turned on.</para>
 611         </listitem>
 612       </varlistentry>
 613       <varlistentry>
 614         <term><varname>RemoteChecksumTx=</varname></term>
 615         <listitem>
 616           <para>A boolean. When true, remote transmit checksum offload of VXLAN is turned on.</para>
 617         </listitem>
 618       </varlistentry>
 619       <varlistentry>
 620         <term><varname>RemoteChecksumRx=</varname></term>
 621         <listitem>
 622           <para>A boolean. When true, remote receive checksum offload in VXLAN is turned on.</para>
 623         </listitem>
 624       </varlistentry>
 625     <varlistentry>
 626       <term><varname>GroupPolicyExtension=</varname></term>
 627       <listitem>
 628         <para>A boolean. When true, it enables Group Policy VXLAN extension security label mechanism
 629         across network peers based on VXLAN. For details about the Group Policy VXLAN, see the
 630         <ulink url="https://tools.ietf.org/html/draft-smith-vxlan-group-policy">
 631         VXLAN Group Policy </ulink> document. Defaults to false.</para>
 632       </listitem>
 633     </varlistentry>
 634     <varlistentry>
 635       <term><varname>DestinationPort=</varname></term>
 636       <listitem>
 637         <para>Configures the default destination UDP port on a per-device basis.
 638         If destination port is not specified then Linux kernel default will be used.
 639         Set destination port 4789 to get the IANA assigned value. If not set or if the
 640         destination port is assigned the empty string the default port of 4789 is used.</para>
 641       </listitem>
 642     </varlistentry>
 643     <varlistentry>
 644       <term><varname>PortRange=</varname></term>
 645         <listitem>
 646           <para>Configures VXLAN port range. VXLAN bases source
 647           UDP port based on flow to help the receiver to be able
 648           to load balance based on outer header flow. It
 649           restricts the port range to the normal UDP local
 650           ports, and allows overriding via configuration.</para>
 651         </listitem>
 652       </varlistentry>
 653     <varlistentry>
 654       <term><varname>FlowLabel=</varname></term>
 655         <listitem>
 656           <para>Specifies the flow label to use in outgoing packets.
 657           The valid range is 0-1048575.
 658           </para>
 659         </listitem>
 660       </varlistentry>
 661     </variablelist>
 662   </refsect1>
 663   <refsect1>
 664     <title>[GENEVE] Section Options</title>
 665     <para>The <literal>[GENEVE]</literal> section only applies for
 666     netdevs of kind <literal>geneve</literal>, and accepts the
 667     following keys:</para>
 668
 669     <variablelist class='network-directives'>
 670       <varlistentry>
 671         <term><varname>Id=</varname></term>
 672         <listitem>
 673           <para>Specifies the Virtual Network Identifier (VNI) to use. Ranges [0-16777215].</para>
 674         </listitem>
 675       </varlistentry>
 676       <varlistentry>
 677         <term><varname>Remote=</varname></term>
 678         <listitem>
 679           <para>Specifies the unicast destination IP address to use in outgoing packets.</para>
 680         </listitem>
 681       </varlistentry>
 682       <varlistentry>
 683         <term><varname>TOS=</varname></term>
 684         <listitem>
 685           <para>Specifies the TOS value to use in outgoing packets. Ranges [1-255].</para>
 686         </listitem>
 687       </varlistentry>
 688       <varlistentry>
 689         <term><varname>TTL=</varname></term>
 690         <listitem>
 691           <para>Specifies the TTL value to use in outgoing packets. Ranges [1-255].</para>
 692         </listitem>
 693       </varlistentry>
 694       <varlistentry>
 695         <term><varname>UDPChecksum=</varname></term>
 696         <listitem>
 697           <para>A boolean. When true, specifies if UDP checksum is calculated for transmitted packets over IPv4.</para>
 698         </listitem>
 699       </varlistentry>
 700       <varlistentry>
 701         <term><varname>UDP6ZeroChecksumTx=</varname></term>
 702         <listitem>
 703           <para>A boolean. When true, skip UDP checksum calculation for transmitted packets over IPv6.</para>
 704         </listitem>
 705       </varlistentry>
 706       <varlistentry>
 707         <term><varname>UDP6ZeroChecksumRx=</varname></term>
 708         <listitem>
 709           <para>A boolean. When true, allows incoming UDP packets over IPv6 with zero checksum field.</para>
 710         </listitem>
 711       </varlistentry>
 712     <varlistentry>
 713       <term><varname>DestinationPort=</varname></term>
 714       <listitem>
 715         <para>Specifies destination port. Defaults to 6081. If not set or assigned the empty string, the default
 716         port of 6081 is used.</para>
 717       </listitem>
 718     </varlistentry>
 719     <varlistentry>
 720       <term><varname>FlowLabel=</varname></term>
 721         <listitem>
 722           <para>Specifies the flow label to use in outgoing packets.</para>
 723         </listitem>
 724       </varlistentry>
 725     </variablelist>
 726   </refsect1>
 727   <refsect1>
 728     <title>[Tunnel] Section Options</title>
 729
 730     <para>The <literal>[Tunnel]</literal> section only applies for
 731     netdevs of kind
 732     <literal>ipip</literal>,
 733     <literal>sit</literal>,
 734     <literal>gre</literal>,
 735     <literal>gretap</literal>,
 736     <literal>ip6gre</literal>,
 737     <literal>ip6gretap</literal>,
 738     <literal>vti</literal>,
 739     <literal>vti6</literal>, and
 740     <literal>ip6tnl</literal> and accepts
 741     the following keys:</para>
 742
 743     <variablelist class='network-directives'>
 744       <varlistentry>
 745         <term><varname>Local=</varname></term>
 746         <listitem>
 747           <para>A static local address for tunneled packets. It must
 748           be an address on another interface of this host.</para>
 749         </listitem>
 750       </varlistentry>
 751       <varlistentry>
 752         <term><varname>Remote=</varname></term>
 753         <listitem>
 754           <para>The remote endpoint of the tunnel.</para>
 755         </listitem>
 756       </varlistentry>
 757       <varlistentry>
 758         <term><varname>TOS=</varname></term>
 759         <listitem>
 760           <para>The Type Of Service byte value for a tunnel interface.
 761           For details about the TOS, see the
 762           <ulink url="http://tools.ietf.org/html/rfc1349"> Type of
 763           Service in the Internet Protocol Suite </ulink> document.
 764           </para>
 765         </listitem>
 766       </varlistentry>
 767       <varlistentry>
 768         <term><varname>TTL=</varname></term>
 769         <listitem>
 770           <para>A fixed Time To Live N on tunneled packets. N is a
 771           number in the range 1–255. 0 is a special value meaning that
 772           packets inherit the TTL value. The default value for IPv4
 773           tunnels is: inherit. The default value for IPv6 tunnels is
 774           64.</para>
 775         </listitem>
 776       </varlistentry>
 777       <varlistentry>
 778         <term><varname>DiscoverPathMTU=</varname></term>
 779         <listitem>
 780           <para>A boolean. When true, enables Path MTU Discovery on
 781           the tunnel.</para>
 782         </listitem>
 783       </varlistentry>
 784       <varlistentry>
 785         <term><varname>IPv6FlowLabel=</varname></term>
 786         <listitem>
 787           <para>Configures the 20-bit flow label (see <ulink url="https://tools.ietf.org/html/rfc6437">
 788           RFC 6437</ulink>) field in the IPv6 header (see <ulink url="https://tools.ietf.org/html/rfc2460">
 789           RFC 2460</ulink>), which is used by a node to label packets of a flow.
 790           It is only used for IPv6 tunnels.
 791           A flow label of zero is used to indicate packets that have
 792           not been labeled.
 793           It can be configured to a value in the range 0–0xFFFFF, or be
 794           set to <literal>inherit</literal>, in which case the original flowlabel is used.</para>
 795         </listitem>
 796       </varlistentry>
 797       <varlistentry>
 798         <term><varname>CopyDSCP=</varname></term>
 799         <listitem>
 800           <para>A boolean. When true, the Differentiated Service Code
 801           Point (DSCP) field will be copied to the inner header from
 802           outer header during the decapsulation of an IPv6 tunnel
 803           packet. DSCP is a field in an IP packet that enables different
 804           levels of service to be assigned to network traffic.
 805           Defaults to <literal>no</literal>.
 806           </para>
 807         </listitem>
 808       </varlistentry>
 809       <varlistentry>
 810         <term><varname>EncapsulationLimit=</varname></term>
 811         <listitem>
 812           <para>The Tunnel Encapsulation Limit option specifies how many additional
 813           levels of encapsulation are permitted to be prepended to the packet.
 814           For example, a Tunnel Encapsulation Limit option containing a limit
 815           value of zero means that a packet carrying that option may not enter
 816           another tunnel before exiting the current tunnel.
 817           (see <ulink url="https://tools.ietf.org/html/rfc2473#section-4.1.1"> RFC 2473</ulink>).
 818           The valid range is 0–255 and <literal>none</literal>. Defaults to 4.
 819         </para>
 820         </listitem>
 821       </varlistentry>
 822       <varlistentry>
 823         <term><varname>Key=</varname></term>
 824         <listitem>
 825           <para>The <varname>Key=</varname> parameter specifies the same key to use in
 826           both directions (<varname>InputKey=</varname> and <varname>OutputKey=</varname>).
 827           The <varname>Key=</varname> is either a number or an IPv4 address-like dotted quad.
 828           It is used as mark-configured SAD/SPD entry as part of the lookup key (both in data
 829           and control path) in ip xfrm (framework used to implement IPsec protocol).
 830           See <ulink url="http://man7.org/linux/man-pages/man8/ip-xfrm.8.html">
 831           ip-xfrm — transform configuration</ulink> for details. It is only used for VTI/VTI6
 832           tunnels.</para>
 833         </listitem>
 834       </varlistentry>
 835       <varlistentry>
 836         <term><varname>InputKey=</varname></term>
 837         <listitem>
 838           <para>The <varname>InputKey=</varname> parameter specifies the key to use for input.
 839           The format is same as <varname>Key=</varname>. It is only used for VTI/VTI6 tunnels.</para>
 840         </listitem>
 841       </varlistentry>
 842       <varlistentry>
 843         <term><varname>OutputKey=</varname></term>
 844         <listitem>
 845           <para>The <varname>OutputKey=</varname> parameter specifies the key to use for output.
 846           The format is same as <varname>Key=</varname>. It is only used for VTI/VTI6 tunnels.</para>
 847         </listitem>
 848       </varlistentry>
 849       <varlistentry>
 850         <term><varname>Mode=</varname></term>
 851         <listitem>
 852           <para>An <literal>ip6tnl</literal> tunnel can be in one of three
 853           modes
 854           <literal>ip6ip6</literal> for IPv6 over IPv6,
 855           <literal>ipip6</literal> for IPv4 over IPv6 or
 856           <literal>any</literal> for either.
 857           </para>
 858         </listitem>
 859       </varlistentry>
 860       <varlistentry>
 861         <term><varname>Independent=</varname></term>
 862         <listitem>
 863           <para>A boolean. When true tunnel does not require .network file. Created as "tunnel@NONE".
 864           Defaults to <literal>false</literal>.
 865           </para>
 866         </listitem>
 867       </varlistentry>
 868     </variablelist>
 869   </refsect1>
 870   <refsect1>
 871     <title>[Peer] Section Options</title>
 872
 873       <para>The <literal>[Peer]</literal> section only applies for
 874       netdevs of kind <literal>veth</literal> and accepts the
 875       following keys:</para>
 876
 877       <variablelist class='network-directives'>
 878         <varlistentry>
 879           <term><varname>Name=</varname></term>
 880           <listitem>
 881             <para>The interface name used when creating the netdev.
 882             This option is compulsory.</para>
 883           </listitem>
 884         </varlistentry>
 885         <varlistentry>
 886           <term><varname>MACAddress=</varname></term>
 887           <listitem>
 888             <para>The peer MACAddress, if not set, it is generated in
 889             the same way as the MAC address of the main
 890             interface.</para>
 891           </listitem>
 892         </varlistentry>
 893       </variablelist>
 894   </refsect1>
 895   <refsect1>
 896     <title>[Tun] Section Options</title>
 897
 898     <para>The <literal>[Tun]</literal> section only applies for
 899     netdevs of kind <literal>tun</literal>, and accepts the following
 900     keys:</para>
 901
 902     <variablelist class='network-directives'>
 903       <varlistentry>
 904         <term><varname>OneQueue=</varname></term>
 905         <listitem><para>Takes a boolean argument. Configures whether
 906         all packets are queued at the device (enabled), or a fixed
 907         number of packets are queued at the device and the rest at the
 908         <literal>qdisc</literal>. Defaults to
 909         <literal>no</literal>.</para>
 910         </listitem>
 911       </varlistentry>
 912       <varlistentry>
 913         <term><varname>MultiQueue=</varname></term>
 914         <listitem><para>Takes a boolean argument. Configures whether
 915         to use multiple file descriptors (queues) to parallelize
 916         packets sending and receiving. Defaults to
 917         <literal>no</literal>.</para>
 918         </listitem>
 919       </varlistentry>
 920       <varlistentry>
 921         <term><varname>PacketInfo=</varname></term>
 922         <listitem><para>Takes a boolean argument. Configures whether
 923         packets should be prepended with four extra bytes (two flag
 924         bytes and two protocol bytes). If disabled, it indicates that
 925         the packets will be pure IP packets. Defaults to
 926         <literal>no</literal>.</para>
 927         </listitem>
 928       </varlistentry>
 929       <varlistentry>
 930         <term><varname>VNetHeader=</varname></term>
 931         <listitem><para>Takes a boolean argument. Configures
 932         IFF_VNET_HDR flag for a tap device. It allows sending
 933         and receiving larger Generic Segmentation Offload (GSO)
 934         packets. This may increase throughput significantly.
 935         Defaults to
 936         <literal>no</literal>.</para>
 937         </listitem>
 938       </varlistentry>
 939       <varlistentry>
 940         <term><varname>User=</varname></term>
 941         <listitem><para>User to grant access to the
 942         <filename>/dev/net/tun</filename> device.</para>
 943         </listitem>
 944       </varlistentry>
 945       <varlistentry>
 946         <term><varname>Group=</varname></term>
 947         <listitem><para>Group to grant access to the
 948         <filename>/dev/net/tun</filename> device.</para>
 949         </listitem>
 950       </varlistentry>
 951
 952     </variablelist>
 953
 954   </refsect1>
 955
 956   <refsect1>
 957     <title>[Tap] Section Options</title>
 958
 959     <para>The <literal>[Tap]</literal> section only applies for
 960     netdevs of kind <literal>tap</literal>, and accepts the same keys
 961     as the <literal>[Tun]</literal> section.</para>
 962   </refsect1>
 963
 964   <refsect1>
 965     <title>[Bond] Section Options</title>
 966
 967     <para>The <literal>[Bond]</literal> section accepts the following
 968     key:</para>
 969
 970     <variablelist class='network-directives'>
 971       <varlistentry>
 972         <term><varname>Mode=</varname></term>
 973         <listitem>
 974           <para>Specifies one of the bonding policies. The default is
 975           <literal>balance-rr</literal> (round robin). Possible values are
 976           <literal>balance-rr</literal>,
 977           <literal>active-backup</literal>,
 978           <literal>balance-xor</literal>,
 979           <literal>broadcast</literal>,
 980           <literal>802.3ad</literal>,
 981           <literal>balance-tlb</literal>, and
 982           <literal>balance-alb</literal>.
 983           </para>
 984         </listitem>
 985       </varlistentry>
 986
 987       <varlistentry>
 988         <term><varname>TransmitHashPolicy=</varname></term>
 989         <listitem>
 990           <para>Selects the transmit hash policy to use for slave
 991           selection in balance-xor, 802.3ad, and tlb modes. Possible
 992           values are
 993           <literal>layer2</literal>,
 994           <literal>layer3+4</literal>,
 995           <literal>layer2+3</literal>,
 996           <literal>encap2+3</literal>, and
 997           <literal>encap3+4</literal>.
 998           </para>
 999         </listitem>
1000       </varlistentry>
1001
1002       <varlistentry>
1003         <term><varname>LACPTransmitRate=</varname></term>
1004         <listitem>
1005           <para>Specifies the rate with which link partner transmits
1006           Link Aggregation Control Protocol Data Unit packets in
1007           802.3ad mode. Possible values are <literal>slow</literal>,
1008           which requests partner to transmit LACPDUs every 30 seconds,
1009           and <literal>fast</literal>, which requests partner to
1010           transmit LACPDUs every second. The default value is
1011           <literal>slow</literal>.</para>
1012         </listitem>
1013       </varlistentry>
1014
1015       <varlistentry>
1016         <term><varname>MIIMonitorSec=</varname></term>
1017         <listitem>
1018           <para>Specifies the frequency that Media Independent
1019           Interface link monitoring will occur. A value of zero
1020           disables MII link monitoring. This value is rounded down to
1021           the nearest millisecond. The default value is 0.</para>
1022         </listitem>
1023       </varlistentry>
1024
1025       <varlistentry>
1026         <term><varname>UpDelaySec=</varname></term>
1027         <listitem>
1028           <para>Specifies the delay before a link is enabled after a
1029           link up status has been detected. This value is rounded down
1030           to a multiple of MIIMonitorSec. The default value is
1031           0.</para>
1032         </listitem>
1033       </varlistentry>
1034
1035       <varlistentry>
1036         <term><varname>DownDelaySec=</varname></term>
1037         <listitem>
1038           <para>Specifies the delay before a link is disabled after a
1039           link down status has been detected. This value is rounded
1040           down to a multiple of MIIMonitorSec. The default value is
1041           0.</para>
1042         </listitem>
1043       </varlistentry>
1044
1045       <varlistentry>
1046         <term><varname>LearnPacketIntervalSec=</varname></term>
1047         <listitem>
1048           <para>Specifies the number of seconds between instances where the bonding
1049           driver sends learning packets to each slave peer switch.
1050           The valid range is 1–0x7fffffff; the default value is 1. This option
1051           has an effect only for the balance-tlb and balance-alb modes.</para>
1052         </listitem>
1053       </varlistentry>
1054
1055       <varlistentry>
1056         <term><varname>AdSelect=</varname></term>
1057         <listitem>
1058           <para>Specifies the 802.3ad aggregation selection logic to use. Possible values are
1059           <literal>stable</literal>,
1060           <literal>bandwidth</literal> and
1061           <literal>count</literal>.
1062           </para>
1063         </listitem>
1064       </varlistentry>
1065
1066       <varlistentry>
1067         <term><varname>FailOverMACPolicy=</varname></term>
1068         <listitem>
1069           <para>Specifies whether the active-backup mode should set all slaves to
1070           the same MAC address at the time of enslavement or, when enabled, to perform special handling of the
1071           bond's MAC address in accordance with the selected policy. The default policy is none.
1072           Possible values are
1073           <literal>none</literal>,
1074           <literal>active</literal> and
1075           <literal>follow</literal>.
1076           </para>
1077         </listitem>
1078       </varlistentry>
1079
1080       <varlistentry>
1081         <term><varname>ARPValidate=</varname></term>
1082         <listitem>
1083           <para>Specifies whether or not ARP probes and replies should be
1084           validated in any mode that supports ARP monitoring, or whether
1085           non-ARP traffic should be filtered (disregarded) for link
1086           monitoring purposes. Possible values are
1087           <literal>none</literal>,
1088           <literal>active</literal>,
1089           <literal>backup</literal> and
1090           <literal>all</literal>.
1091           </para>
1092         </listitem>
1093       </varlistentry>
1094
1095       <varlistentry>
1096         <term><varname>ARPIntervalSec=</varname></term>
1097         <listitem>
1098           <para>Specifies the ARP link monitoring frequency in milliseconds.
1099           A value of 0 disables ARP monitoring. The default value is 0.
1100           </para>
1101         </listitem>
1102       </varlistentry>
1103
1104       <varlistentry>
1105         <term><varname>ARPIPTargets=</varname></term>
1106         <listitem>
1107           <para>Specifies the IP addresses to use as ARP monitoring peers when
1108           ARPIntervalSec is greater than 0. These are the targets of the ARP request
1109           sent to determine the health of the link to the targets.
1110           Specify these values in IPv4 dotted decimal format. At least one IP
1111           address must be given for ARP monitoring to function. The
1112           maximum number of targets that can be specified is 16. The
1113           default value is no IP addresses.
1114           </para>
1115         </listitem>
1116       </varlistentry>
1117
1118       <varlistentry>
1119         <term><varname>ARPAllTargets=</varname></term>
1120         <listitem>
1121           <para>Specifies the quantity of ARPIPTargets that must be reachable
1122           in order for the ARP monitor to consider a slave as being up.
1123           This option affects only active-backup mode for slaves with
1124           ARPValidate enabled. Possible values are
1125           <literal>any</literal> and
1126           <literal>all</literal>.
1127           </para>
1128         </listitem>
1129       </varlistentry>
1130
1131       <varlistentry>
1132         <term><varname>PrimaryReselectPolicy=</varname></term>
1133         <listitem>
1134           <para>Specifies the reselection policy for the primary slave.  This
1135           affects how the primary slave is chosen to become the active slave
1136           when failure of the active slave or recovery of the primary slave
1137           occurs. This option is designed to prevent flip-flopping between
1138           the primary slave and other slaves.  Possible values are
1139           <literal>always</literal>,
1140           <literal>better</literal> and
1141           <literal>failure</literal>.
1142           </para>
1143         </listitem>
1144       </varlistentry>
1145
1146       <varlistentry>
1147         <term><varname>ResendIGMP=</varname></term>
1148         <listitem>
1149           <para>Specifies the number of IGMP membership reports to be issued after
1150           a failover event. One membership report is issued immediately after
1151           the failover, subsequent packets are sent in each 200ms interval.
1152           The valid range is 0–255. Defaults to 1. A value of 0
1153           prevents the IGMP membership report from being issued in response
1154           to the failover event.
1155           </para>
1156         </listitem>
1157       </varlistentry>
1158
1159       <varlistentry>
1160         <term><varname>PacketsPerSlave=</varname></term>
1161         <listitem>
1162           <para>Specify the number of packets to transmit through a slave before
1163             moving to the next one. When set to 0, then a slave is chosen at
1164             random. The valid range is 0–65535. Defaults to 1. This option
1165             only has effect when in balance-rr mode.
1166           </para>
1167         </listitem>
1168       </varlistentry>
1169
1170       <varlistentry>
1171         <term><varname>GratuitousARP=</varname></term>
1172         <listitem>
1173           <para>Specify the number of peer notifications (gratuitous ARPs and
1174             unsolicited IPv6 Neighbor Advertisements) to be issued after a
1175             failover event.  As soon as the link is up on the new slave,
1176             a peer notification is sent on the  bonding device and each
1177             VLAN sub-device.  This is repeated at each link monitor interval
1178             (ARPIntervalSec or MIIMonitorSec, whichever is active) if the number is
1179             greater than 1. The valid range is 0–255. The default value is 1.
1180             These options affect only the active-backup mode.
1181           </para>
1182         </listitem>
1183       </varlistentry>
1184
1185       <varlistentry>
1186         <term><varname>AllSlavesActive=</varname></term>
1187         <listitem>
1188           <para>A boolean. Specifies that duplicate frames (received on inactive ports)
1189           should be dropped when false, or delivered when true. Normally, bonding will drop
1190           duplicate frames (received on inactive ports), which is desirable for
1191           most users. But there are some times it is nice to allow duplicate
1192           frames to be delivered. The default value is false (drop duplicate frames
1193           received on inactive ports).
1194           </para>
1195         </listitem>
1196       </varlistentry>
1197
1198       <varlistentry>
1199         <term><varname>MinLinks=</varname></term>
1200         <listitem>
1201           <para>Specifies the minimum number of links that must be active before
1202           asserting carrier. The default value is 0.
1203           </para>
1204         </listitem>
1205       </varlistentry>
1206     </variablelist>
1207
1208     <para>For more detail information see
1209     <ulink url="https://www.kernel.org/doc/Documentation/networking/bonding.txt">
1210     Linux Ethernet Bonding Driver HOWTO</ulink></para>
1211
1212   </refsect1>
1213
1214   <refsect1>
1215     <title>Example</title>
1216     <example>
1217       <title>/etc/systemd/network/25-bridge.netdev</title>
1218
1219       <programlisting>[NetDev]
1220 Name=bridge0
1221 Kind=bridge</programlisting>
1222     </example>
1223
1224     <example>
1225       <title>/etc/systemd/network/25-vlan1.netdev</title>
1226
1227       <programlisting>[Match]
1228 Virtualization=no
1229
1230 [NetDev]
1231 Name=vlan1
1232 Kind=vlan
1233
1234 [VLAN]
1235 Id=1</programlisting>
1236     </example>
1237     <example>
1238       <title>/etc/systemd/network/25-ipip.netdev</title>
1239       <programlisting>[NetDev]
1240 Name=ipip-tun
1241 Kind=ipip
1242 MTUBytes=1480
1243
1244 [Tunnel]
1245 Local=192.168.223.238
1246 Remote=192.169.224.239
1247 TTL=64</programlisting>
1248     </example>
1249     <example>
1250       <title>/etc/systemd/network/25-tap.netdev</title>
1251       <programlisting>[NetDev]
1252 Name=tap-test
1253 Kind=tap
1254
1255 [Tap]
1256 MultiQueue=true
1257 PacketInfo=true</programlisting> </example>
1258
1259     <example>
1260       <title>/etc/systemd/network/25-sit.netdev</title>
1261       <programlisting>[NetDev]
1262 Name=sit-tun
1263 Kind=sit
1264 MTUBytes=1480
1265
1266 [Tunnel]
1267 Local=10.65.223.238
1268 Remote=10.65.223.239</programlisting>
1269     </example>
1270
1271     <example>
1272       <title>/etc/systemd/network/25-gre.netdev</title>
1273       <programlisting>[NetDev]
1274 Name=gre-tun
1275 Kind=gre
1276 MTUBytes=1480
1277
1278 [Tunnel]
1279 Local=10.65.223.238
1280 Remote=10.65.223.239</programlisting>
1281     </example>
1282
1283     <example>
1284       <title>/etc/systemd/network/25-vti.netdev</title>
1285
1286       <programlisting>[NetDev]
1287 Name=vti-tun
1288 Kind=vti
1289 MTUBytes=1480
1290
1291 [Tunnel]
1292 Local=10.65.223.238
1293 Remote=10.65.223.239</programlisting>
1294     </example>
1295
1296     <example>
1297       <title>/etc/systemd/network/25-veth.netdev</title>
1298       <programlisting>[NetDev]
1299 Name=veth-test
1300 Kind=veth
1301
1302 [Peer]
1303 Name=veth-peer</programlisting>
1304     </example>
1305
1306     <example>
1307       <title>/etc/systemd/network/25-bond.netdev</title>
1308       <programlisting>[NetDev]
1309 Name=bond1
1310 Kind=bond
1311
1312 [Bond]
1313 Mode=802.3ad
1314 TransmitHashPolicy=layer3+4
1315 MIIMonitorSec=1s
1316 LACPTransmitRate=fast
1317 </programlisting>
1318     </example>
1319
1320     <example>
1321       <title>/etc/systemd/network/25-dummy.netdev</title>
1322       <programlisting>[NetDev]
1323 Name=dummy-test
1324 Kind=dummy
1325 MACAddress=12:34:56:78:9a:bc</programlisting>
1326     </example>
1327     <example>
1328       <title>/etc/systemd/network/25-vrf.netdev</title>
1329       <para>Create a VRF interface with table 42.</para>
1330       <programlisting>[NetDev]
1331 Name=vrf-test
1332 Kind=vrf
1333
1334 [VRF]
1335 Table=42</programlisting>
1336     </example>
1337
1338     <example>
1339       <title>/etc/systemd/network/25-macvtap.netdev</title>
1340       <para>Create a MacVTap device.</para>
1341       <programlisting>[NetDev]
1342 Name=macvtap-test
1343 Kind=macvtap
1344       </programlisting>
1345     </example>
1346   </refsect1>
1347   <refsect1>
1348     <title>See Also</title>
1349     <para>
1350       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1351       <citerefentry><refentrytitle>systemd-networkd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
1352       <citerefentry><refentrytitle>systemd.link</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1353       <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>
1354     </para>
1355   </refsect1>
1356
1357 </refentry>