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           <row><entry><varname>vxcan</varname></entry>
 184           <entry>The virtual CAN tunnel driver (vxcan). Similar to the virtual ethernet driver veth, vxcan implements a local CAN traffic tunnel between two virtual CAN network devices. When creating a vxcan, two vxcan devices are created as pair. When one end receives the packet it appears on its pair and vice versa. The vxcan can be used for cross namespace communication.
 185           </entry></row>
 186
 187         </tbody>
 188       </tgroup>
 189     </table>
 190
 191   </refsect1>
 192
 193   <refsect1>
 194     <title>[Match] Section Options</title>
 195
 196     <para>A virtual network device is only created if the
 197     <literal>[Match]</literal> section matches the current
 198     environment, or if the section is empty. The following keys are
 199     accepted:</para>
 200
 201     <variablelist class='network-directives'>
 202       <varlistentry>
 203         <term><varname>Host=</varname></term>
 204         <listitem>
 205           <para>Matches against the hostname or machine ID of the
 206           host. See <literal>ConditionHost=</literal> in
 207           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 208           for details.
 209           </para>
 210         </listitem>
 211       </varlistentry>
 212       <varlistentry>
 213         <term><varname>Virtualization=</varname></term>
 214         <listitem>
 215           <para>Checks whether the system is executed in a virtualized
 216           environment and optionally test whether it is a specific
 217           implementation. See
 218           <literal>ConditionVirtualization=</literal> in
 219           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 220           for details.
 221           </para>
 222         </listitem>
 223       </varlistentry>
 224       <varlistentry>
 225         <term><varname>KernelCommandLine=</varname></term>
 226         <listitem>
 227           <para>Checks whether a specific kernel command line option
 228           is set (or if prefixed with the exclamation mark unset). See
 229           <literal>ConditionKernelCommandLine=</literal> in
 230           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 231           for details.
 232           </para>
 233         </listitem>
 234       </varlistentry>
 235       <varlistentry>
 236         <term><varname>KernelVersion=</varname></term>
 237         <listitem>
 238           <para>Checks whether the kernel version (as reported by <command>uname -r</command>) matches a certain
 239           expression (or if prefixed with the exclamation mark does not match it). See
 240           <literal>ConditionKernelVersion=</literal> in
 241           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry> for details.
 242           </para>
 243         </listitem>
 244       </varlistentry>
 245       <varlistentry>
 246         <term><varname>Architecture=</varname></term>
 247         <listitem>
 248           <para>Checks whether the system is running on a specific
 249           architecture. See <literal>ConditionArchitecture=</literal> in
 250           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 251           for details.
 252           </para>
 253         </listitem>
 254       </varlistentry>
 255     </variablelist>
 256
 257   </refsect1>
 258
 259   <refsect1>
 260     <title>[NetDev] Section Options</title>
 261
 262       <para>The <literal>[NetDev]</literal> section accepts the
 263       following keys:</para>
 264
 265       <variablelist class='network-directives'>
 266         <varlistentry>
 267           <term><varname>Description=</varname></term>
 268           <listitem>
 269             <para>A free-form description of the netdev.</para>
 270           </listitem>
 271         </varlistentry>
 272         <varlistentry>
 273           <term><varname>Name=</varname></term>
 274           <listitem>
 275             <para>The interface name used when creating the netdev.
 276             This option is compulsory.</para>
 277           </listitem>
 278         </varlistentry>
 279         <varlistentry>
 280           <term><varname>Kind=</varname></term>
 281           <listitem>
 282             <para>The netdev kind. This option is compulsory. See the
 283             <literal>Supported netdev kinds</literal> section for the
 284             valid keys.</para>
 285           </listitem>
 286         </varlistentry>
 287         <varlistentry>
 288           <term><varname>MTUBytes=</varname></term>
 289           <listitem>
 290             <para>The maximum transmission unit in bytes to set for
 291             the device. The usual suffixes K, M, G, are supported and
 292             are understood to the base of 1024. This key is not
 293             currently supported for <literal>tun</literal> or
 294             <literal>tap</literal> devices.
 295             </para>
 296           </listitem>
 297         </varlistentry>
 298         <varlistentry>
 299           <term><varname>MACAddress=</varname></term>
 300           <listitem>
 301             <para>The MAC address to use for the device. If none is
 302             given, one is generated based on the interface name and
 303             the
 304             <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
 305             This key is not currently supported for
 306             <literal>tun</literal> or <literal>tap</literal> devices.
 307             </para>
 308           </listitem>
 309         </varlistentry>
 310       </variablelist>
 311   </refsect1>
 312
 313     <refsect1>
 314     <title>[Bridge] Section Options</title>
 315
 316       <para>The <literal>[Bridge]</literal> section only applies for
 317       netdevs of kind <literal>bridge</literal>, and accepts the
 318       following keys:</para>
 319
 320       <variablelist class='network-directives'>
 321         <varlistentry>
 322           <term><varname>HelloTimeSec=</varname></term>
 323           <listitem>
 324             <para>HelloTimeSec specifies the number of seconds between two hello packets
 325             sent out by the root bridge and the designated bridges. Hello packets are
 326             used to communicate information about the topology throughout the entire
 327             bridged local area network.</para>
 328           </listitem>
 329         </varlistentry>
 330         <varlistentry>
 331           <term><varname>MaxAgeSec=</varname></term>
 332           <listitem>
 333             <para>MaxAgeSec specifies the number of seconds of maximum message age.
 334             If the last seen (received) hello packet is more than this number of
 335             seconds old, the bridge in question will start the takeover procedure
 336             in attempt to become the Root Bridge itself.</para>
 337           </listitem>
 338         </varlistentry>
 339         <varlistentry>
 340           <term><varname>ForwardDelaySec=</varname></term>
 341           <listitem>
 342             <para>ForwardDelaySec specifies the number of seconds spent in each
 343             of the Listening and Learning states before the Forwarding state is entered.</para>
 344           </listitem>
 345         </varlistentry>
 346         <varlistentry>
 347           <term><varname>AgeingTimeSec=</varname></term>
 348           <listitem>
 349             <para>This specifies the number of seconds a MAC Address will be kept in
 350             the forwarding database after having a packet received from this MAC Address.</para>
 351           </listitem>
 352         </varlistentry>
 353         <varlistentry>
 354           <term><varname>Priority=</varname></term>
 355           <listitem>
 356             <para>The priority of the bridge. An integer between 0 and 65535. A lower value
 357             means higher priority. The bridge having the lowest priority will be elected as root bridge.</para>
 358           </listitem>
 359         </varlistentry>
 360         <varlistentry>
 361           <term><varname>GroupForwardMask=</varname></term>
 362           <listitem>
 363             <para>A 16-bit bitmask represented as an integer which allows forwarding of link
 364             local frames with 802.1D reserved addresses (01:80:C2:00:00:0X). A logical AND
 365             is performed between the specified bitmask and the exponentiation of 2^X, the
 366             lower nibble of the last octet of the MAC address. For example, a value of 8
 367             would allow forwarding of frames addressed to 01:80:C2:00:00:03 (802.1X PAE).</para>
 368           </listitem>
 369         </varlistentry>
 370         <varlistentry>
 371           <term><varname>DefaultPVID=</varname></term>
 372           <listitem>
 373             <para>This specifies the default port VLAN ID of a newly attached bridge port.
 374             Set this to an integer in the range 1–4094 or <literal>none</literal> to disable the PVID.</para>
 375           </listitem>
 376         </varlistentry>
 377         <varlistentry>
 378           <term><varname>MulticastQuerier=</varname></term>
 379           <listitem>
 380             <para>A boolean. This setting controls the IFLA_BR_MCAST_QUERIER option in the kernel.
 381             If enabled, the kernel will send general ICMP queries from a zero source address.
 382             This feature should allow faster convergence on startup, but it causes some
 383             multicast-aware switches to misbehave and disrupt forwarding of multicast packets.
 384             When unset, the kernel's default setting applies.
 385             </para>
 386           </listitem>
 387         </varlistentry>
 388         <varlistentry>
 389           <term><varname>MulticastSnooping=</varname></term>
 390           <listitem>
 391             <para>A boolean. This setting controls the IFLA_BR_MCAST_SNOOPING option in the kernel.
 392             If enabled, IGMP snooping monitors the Internet Group Management Protocol (IGMP) traffic
 393             between hosts and multicast routers. When unset, the kernel's default setting applies.
 394             </para>
 395           </listitem>
 396         </varlistentry>
 397         <varlistentry>
 398           <term><varname>VLANFiltering=</varname></term>
 399           <listitem>
 400             <para>A boolean. This setting controls the IFLA_BR_VLAN_FILTERING option in the kernel.
 401             If enabled, the bridge will be started in VLAN-filtering mode. When unset, the kernel's
 402             default setting applies.
 403             </para>
 404           </listitem>
 405         </varlistentry>
 406           <varlistentry>
 407           <term><varname>STP=</varname></term>
 408           <listitem>
 409             <para>A boolean. This enables the bridge's Spanning Tree Protocol (STP). When unset,
 410             the kernel's default setting applies.
 411             </para>
 412           </listitem>
 413         </varlistentry>
 414       </variablelist>
 415   </refsect1>
 416
 417   <refsect1>
 418     <title>[VLAN] Section Options</title>
 419
 420       <para>The <literal>[VLAN]</literal> section only applies for
 421       netdevs of kind <literal>vlan</literal>, and accepts the
 422       following key:</para>
 423
 424       <variablelist class='network-directives'>
 425         <varlistentry>
 426           <term><varname>Id=</varname></term>
 427           <listitem>
 428             <para>The VLAN ID to use. An integer in the range 0–4094.
 429             This option is compulsory.</para>
 430           </listitem>
 431         </varlistentry>
 432         <varlistentry>
 433           <term><varname>GVRP=</varname></term>
 434           <listitem>
 435             <para>The Generic VLAN Registration Protocol (GVRP) is a protocol that
 436             allows automatic learning of VLANs on a network. A boolean. When unset,
 437             the kernel's default setting applies.</para>
 438           </listitem>
 439         </varlistentry>
 440         <varlistentry>
 441           <term><varname>MVRP=</varname></term>
 442           <listitem>
 443             <para>Multiple VLAN Registration Protocol (MVRP) formerly known as GARP VLAN
 444             Registration Protocol (GVRP) is a standards-based Layer 2 network protocol,
 445             for automatic configuration of VLAN information on switches. It was defined
 446             in the 802.1ak amendment to 802.1Q-2005. A boolean. When unset, the kernel's
 447             default setting applies.</para>
 448           </listitem>
 449         </varlistentry>
 450         <varlistentry>
 451           <term><varname>LooseBinding=</varname></term>
 452           <listitem>
 453             <para>The VLAN loose binding mode, in which only the operational state is passed
 454             from the parent to the associated VLANs, but the VLAN device state is not changed.
 455             A boolean. When unset, the kernel's default setting applies.</para>
 456           </listitem>
 457         </varlistentry>
 458         <varlistentry>
 459           <term><varname>ReorderHeader=</varname></term>
 460           <listitem>
 461             <para>The VLAN reorder header is set VLAN interfaces behave like physical interfaces.
 462             A boolean. When unset, the kernel's default setting applies.</para>
 463           </listitem>
 464         </varlistentry>
 465       </variablelist>
 466   </refsect1>
 467
 468   <refsect1>
 469     <title>[MACVLAN] Section Options</title>
 470
 471     <para>The <literal>[MACVLAN]</literal> section only applies for
 472     netdevs of kind <literal>macvlan</literal>, and accepts the
 473     following key:</para>
 474
 475     <variablelist class='network-directives'>
 476       <varlistentry>
 477         <term><varname>Mode=</varname></term>
 478         <listitem>
 479           <para>The MACVLAN mode to use. The supported options are
 480           <literal>private</literal>,
 481           <literal>vepa</literal>,
 482           <literal>bridge</literal>, and
 483           <literal>passthru</literal>.
 484           </para>
 485         </listitem>
 486       </varlistentry>
 487     </variablelist>
 488
 489   </refsect1>
 490
 491     <refsect1>
 492     <title>[MACVTAP] Section Options</title>
 493
 494     <para>The <literal>[MACVTAP]</literal> section applies for
 495     netdevs of kind <literal>macvtap</literal> and accepts the
 496     same key as <literal>[MACVLAN]</literal>.</para>
 497
 498     </refsect1>
 499
 500   <refsect1>
 501     <title>[IPVLAN] Section Options</title>
 502
 503     <para>The <literal>[IPVLAN]</literal> section only applies for
 504     netdevs of kind <literal>ipvlan</literal>, and accepts the
 505     following key:</para>
 506
 507     <variablelist class='network-directives'>
 508       <varlistentry>
 509         <term><varname>Mode=</varname></term>
 510           <listitem>
 511             <para>The IPVLAN mode to use. The supported options are
 512             <literal>L2</literal>,<literal>L3</literal> and <literal>L3S</literal>.
 513             </para>
 514           </listitem>
 515       </varlistentry>
 516        <varlistentry>
 517         <term><varname>Flags=</varname></term>
 518           <listitem>
 519             <para>The IPVLAN flags to use. The supported options are
 520             <literal>bridge</literal>,<literal>private</literal> and <literal>vepa</literal>.
 521             </para>
 522           </listitem>
 523       </varlistentry>
 524     </variablelist>
 525
 526   </refsect1>
 527
 528   <refsect1>
 529     <title>[VXLAN] Section Options</title>
 530     <para>The <literal>[VXLAN]</literal> section only applies for
 531     netdevs of kind <literal>vxlan</literal>, and accepts the
 532     following keys:</para>
 533
 534     <variablelist class='network-directives'>
 535       <varlistentry>
 536         <term><varname>Id=</varname></term>
 537         <listitem>
 538           <para>The VXLAN ID to use.</para>
 539         </listitem>
 540       </varlistentry>
 541       <varlistentry>
 542         <term><varname>Remote=</varname></term>
 543         <listitem>
 544           <para>Configures destination multicast group IP address.</para>
 545         </listitem>
 546       </varlistentry>
 547       <varlistentry>
 548         <term><varname>Local=</varname></term>
 549         <listitem>
 550           <para>Configures local IP address.</para>
 551         </listitem>
 552       </varlistentry>
 553         <varlistentry>
 554         <term><varname>TOS=</varname></term>
 555         <listitem>
 556           <para>The Type Of Service byte value for a vxlan interface.</para>
 557         </listitem>
 558       </varlistentry>
 559       <varlistentry>
 560         <term><varname>TTL=</varname></term>
 561         <listitem>
 562           <para>A fixed Time To Live N on Virtual eXtensible Local
 563           Area Network packets. N is a number in the range 1–255. 0
 564           is a special value meaning that packets inherit the TTL
 565           value.</para>
 566         </listitem>
 567       </varlistentry>
 568       <varlistentry>
 569         <term><varname>MacLearning=</varname></term>
 570         <listitem>
 571           <para>A boolean. When true, enables dynamic MAC learning
 572           to discover remote MAC addresses.</para>
 573         </listitem>
 574       </varlistentry>
 575       <varlistentry>
 576         <term><varname>FDBAgeingSec=</varname></term>
 577         <listitem>
 578           <para>The lifetime of Forwarding Database entry learnt by
 579           the kernel, in seconds.</para>
 580         </listitem>
 581       </varlistentry>
 582       <varlistentry>
 583         <term><varname>MaximumFDBEntries=</varname></term>
 584         <listitem>
 585           <para>Configures maximum number of FDB entries.</para>
 586         </listitem>
 587       </varlistentry>
 588       <varlistentry>
 589         <term><varname>ReduceARPProxy=</varname></term>
 590         <listitem>
 591           <para>A boolean. When true, bridge-connected VXLAN tunnel
 592           endpoint answers ARP requests from the local bridge on behalf
 593           of remote Distributed Overlay Virtual Ethernet
 594           <ulink url="https://en.wikipedia.org/wiki/Distributed_Overlay_Virtual_Ethernet">
 595           (DVOE)</ulink> clients. Defaults to false.</para>
 596         </listitem>
 597       </varlistentry>
 598       <varlistentry>
 599         <term><varname>L2MissNotification=</varname></term>
 600         <listitem>
 601           <para>A boolean. When true, enables netlink LLADDR miss
 602           notifications.</para>
 603         </listitem>
 604       </varlistentry>
 605       <varlistentry>
 606         <term><varname>L3MissNotification=</varname></term>
 607         <listitem>
 608           <para>A boolean. When true, enables netlink IP address miss
 609           notifications.</para>
 610         </listitem>
 611       </varlistentry>
 612       <varlistentry>
 613         <term><varname>RouteShortCircuit=</varname></term>
 614         <listitem>
 615           <para>A boolean. When true, route short circuiting is turned
 616           on.</para>
 617         </listitem>
 618       </varlistentry>
 619       <varlistentry>
 620         <term><varname>UDPChecksum=</varname></term>
 621         <listitem>
 622           <para>A boolean. When true, transmitting UDP checksums when doing VXLAN/IPv4 is turned on.</para>
 623         </listitem>
 624       </varlistentry>
 625       <varlistentry>
 626         <term><varname>UDP6ZeroChecksumTx=</varname></term>
 627         <listitem>
 628           <para>A boolean. When true, sending zero checksums in VXLAN/IPv6 is turned on.</para>
 629         </listitem>
 630       </varlistentry>
 631       <varlistentry>
 632         <term><varname>UDP6ZeroChecksumRx=</varname></term>
 633         <listitem>
 634           <para>A boolean. When true, receiving zero checksums in VXLAN/IPv6 is turned on.</para>
 635         </listitem>
 636       </varlistentry>
 637       <varlistentry>
 638         <term><varname>RemoteChecksumTx=</varname></term>
 639         <listitem>
 640           <para>A boolean. When true, remote transmit checksum offload of VXLAN is turned on.</para>
 641         </listitem>
 642       </varlistentry>
 643       <varlistentry>
 644         <term><varname>RemoteChecksumRx=</varname></term>
 645         <listitem>
 646           <para>A boolean. When true, remote receive checksum offload in VXLAN is turned on.</para>
 647         </listitem>
 648       </varlistentry>
 649     <varlistentry>
 650       <term><varname>GroupPolicyExtension=</varname></term>
 651       <listitem>
 652         <para>A boolean. When true, it enables Group Policy VXLAN extension security label mechanism
 653         across network peers based on VXLAN. For details about the Group Policy VXLAN, see the
 654         <ulink url="https://tools.ietf.org/html/draft-smith-vxlan-group-policy">
 655         VXLAN Group Policy </ulink> document. Defaults to false.</para>
 656       </listitem>
 657     </varlistentry>
 658     <varlistentry>
 659       <term><varname>DestinationPort=</varname></term>
 660       <listitem>
 661         <para>Configures the default destination UDP port on a per-device basis.
 662         If destination port is not specified then Linux kernel default will be used.
 663         Set destination port 4789 to get the IANA assigned value. If not set or if the
 664         destination port is assigned the empty string the default port of 4789 is used.</para>
 665       </listitem>
 666     </varlistentry>
 667     <varlistentry>
 668       <term><varname>PortRange=</varname></term>
 669         <listitem>
 670           <para>Configures VXLAN port range. VXLAN bases source
 671           UDP port based on flow to help the receiver to be able
 672           to load balance based on outer header flow. It
 673           restricts the port range to the normal UDP local
 674           ports, and allows overriding via configuration.</para>
 675         </listitem>
 676       </varlistentry>
 677     <varlistentry>
 678       <term><varname>FlowLabel=</varname></term>
 679         <listitem>
 680           <para>Specifies the flow label to use in outgoing packets.
 681           The valid range is 0-1048575.
 682           </para>
 683         </listitem>
 684       </varlistentry>
 685     </variablelist>
 686   </refsect1>
 687   <refsect1>
 688     <title>[GENEVE] Section Options</title>
 689     <para>The <literal>[GENEVE]</literal> section only applies for
 690     netdevs of kind <literal>geneve</literal>, and accepts the
 691     following keys:</para>
 692
 693     <variablelist class='network-directives'>
 694       <varlistentry>
 695         <term><varname>Id=</varname></term>
 696         <listitem>
 697           <para>Specifies the Virtual Network Identifier (VNI) to use. Ranges [0-16777215].</para>
 698         </listitem>
 699       </varlistentry>
 700       <varlistentry>
 701         <term><varname>Remote=</varname></term>
 702         <listitem>
 703           <para>Specifies the unicast destination IP address to use in outgoing packets.</para>
 704         </listitem>
 705       </varlistentry>
 706       <varlistentry>
 707         <term><varname>TOS=</varname></term>
 708         <listitem>
 709           <para>Specifies the TOS value to use in outgoing packets. Ranges [1-255].</para>
 710         </listitem>
 711       </varlistentry>
 712       <varlistentry>
 713         <term><varname>TTL=</varname></term>
 714         <listitem>
 715           <para>Specifies the TTL value to use in outgoing packets. Ranges [1-255].</para>
 716         </listitem>
 717       </varlistentry>
 718       <varlistentry>
 719         <term><varname>UDPChecksum=</varname></term>
 720         <listitem>
 721           <para>A boolean. When true, specifies if UDP checksum is calculated for transmitted packets over IPv4.</para>
 722         </listitem>
 723       </varlistentry>
 724       <varlistentry>
 725         <term><varname>UDP6ZeroChecksumTx=</varname></term>
 726         <listitem>
 727           <para>A boolean. When true, skip UDP checksum calculation for transmitted packets over IPv6.</para>
 728         </listitem>
 729       </varlistentry>
 730       <varlistentry>
 731         <term><varname>UDP6ZeroChecksumRx=</varname></term>
 732         <listitem>
 733           <para>A boolean. When true, allows incoming UDP packets over IPv6 with zero checksum field.</para>
 734         </listitem>
 735       </varlistentry>
 736     <varlistentry>
 737       <term><varname>DestinationPort=</varname></term>
 738       <listitem>
 739         <para>Specifies destination port. Defaults to 6081. If not set or assigned the empty string, the default
 740         port of 6081 is used.</para>
 741       </listitem>
 742     </varlistentry>
 743     <varlistentry>
 744       <term><varname>FlowLabel=</varname></term>
 745         <listitem>
 746           <para>Specifies the flow label to use in outgoing packets.</para>
 747         </listitem>
 748       </varlistentry>
 749     </variablelist>
 750   </refsect1>
 751   <refsect1>
 752     <title>[Tunnel] Section Options</title>
 753
 754     <para>The <literal>[Tunnel]</literal> section only applies for
 755     netdevs of kind
 756     <literal>ipip</literal>,
 757     <literal>sit</literal>,
 758     <literal>gre</literal>,
 759     <literal>gretap</literal>,
 760     <literal>ip6gre</literal>,
 761     <literal>ip6gretap</literal>,
 762     <literal>vti</literal>,
 763     <literal>vti6</literal>, and
 764     <literal>ip6tnl</literal> and accepts
 765     the following keys:</para>
 766
 767     <variablelist class='network-directives'>
 768       <varlistentry>
 769         <term><varname>Local=</varname></term>
 770         <listitem>
 771           <para>A static local address for tunneled packets. It must
 772           be an address on another interface of this host.</para>
 773         </listitem>
 774       </varlistentry>
 775       <varlistentry>
 776         <term><varname>Remote=</varname></term>
 777         <listitem>
 778           <para>The remote endpoint of the tunnel.</para>
 779         </listitem>
 780       </varlistentry>
 781       <varlistentry>
 782         <term><varname>TOS=</varname></term>
 783         <listitem>
 784           <para>The Type Of Service byte value for a tunnel interface.
 785           For details about the TOS, see the
 786           <ulink url="http://tools.ietf.org/html/rfc1349"> Type of
 787           Service in the Internet Protocol Suite </ulink> document.
 788           </para>
 789         </listitem>
 790       </varlistentry>
 791       <varlistentry>
 792         <term><varname>TTL=</varname></term>
 793         <listitem>
 794           <para>A fixed Time To Live N on tunneled packets. N is a
 795           number in the range 1–255. 0 is a special value meaning that
 796           packets inherit the TTL value. The default value for IPv4
 797           tunnels is: inherit. The default value for IPv6 tunnels is
 798           64.</para>
 799         </listitem>
 800       </varlistentry>
 801       <varlistentry>
 802         <term><varname>DiscoverPathMTU=</varname></term>
 803         <listitem>
 804           <para>A boolean. When true, enables Path MTU Discovery on
 805           the tunnel.</para>
 806         </listitem>
 807       </varlistentry>
 808       <varlistentry>
 809         <term><varname>IPv6FlowLabel=</varname></term>
 810         <listitem>
 811           <para>Configures the 20-bit flow label (see <ulink url="https://tools.ietf.org/html/rfc6437">
 812           RFC 6437</ulink>) field in the IPv6 header (see <ulink url="https://tools.ietf.org/html/rfc2460">
 813           RFC 2460</ulink>), which is used by a node to label packets of a flow.
 814           It is only used for IPv6 tunnels.
 815           A flow label of zero is used to indicate packets that have
 816           not been labeled.
 817           It can be configured to a value in the range 0–0xFFFFF, or be
 818           set to <literal>inherit</literal>, in which case the original flowlabel is used.</para>
 819         </listitem>
 820       </varlistentry>
 821       <varlistentry>
 822         <term><varname>CopyDSCP=</varname></term>
 823         <listitem>
 824           <para>A boolean. When true, the Differentiated Service Code
 825           Point (DSCP) field will be copied to the inner header from
 826           outer header during the decapsulation of an IPv6 tunnel
 827           packet. DSCP is a field in an IP packet that enables different
 828           levels of service to be assigned to network traffic.
 829           Defaults to <literal>no</literal>.
 830           </para>
 831         </listitem>
 832       </varlistentry>
 833       <varlistentry>
 834         <term><varname>EncapsulationLimit=</varname></term>
 835         <listitem>
 836           <para>The Tunnel Encapsulation Limit option specifies how many additional
 837           levels of encapsulation are permitted to be prepended to the packet.
 838           For example, a Tunnel Encapsulation Limit option containing a limit
 839           value of zero means that a packet carrying that option may not enter
 840           another tunnel before exiting the current tunnel.
 841           (see <ulink url="https://tools.ietf.org/html/rfc2473#section-4.1.1"> RFC 2473</ulink>).
 842           The valid range is 0–255 and <literal>none</literal>. Defaults to 4.
 843         </para>
 844         </listitem>
 845       </varlistentry>
 846       <varlistentry>
 847         <term><varname>Key=</varname></term>
 848         <listitem>
 849           <para>The <varname>Key=</varname> parameter specifies the same key to use in
 850           both directions (<varname>InputKey=</varname> and <varname>OutputKey=</varname>).
 851           The <varname>Key=</varname> is either a number or an IPv4 address-like dotted quad.
 852           It is used as mark-configured SAD/SPD entry as part of the lookup key (both in data
 853           and control path) in ip xfrm (framework used to implement IPsec protocol).
 854           See <ulink url="http://man7.org/linux/man-pages/man8/ip-xfrm.8.html">
 855           ip-xfrm — transform configuration</ulink> for details. It is only used for VTI/VTI6
 856           tunnels.</para>
 857         </listitem>
 858       </varlistentry>
 859       <varlistentry>
 860         <term><varname>InputKey=</varname></term>
 861         <listitem>
 862           <para>The <varname>InputKey=</varname> parameter specifies the key to use for input.
 863           The format is same as <varname>Key=</varname>. It is only used for VTI/VTI6 tunnels.</para>
 864         </listitem>
 865       </varlistentry>
 866       <varlistentry>
 867         <term><varname>OutputKey=</varname></term>
 868         <listitem>
 869           <para>The <varname>OutputKey=</varname> parameter specifies the key to use for output.
 870           The format is same as <varname>Key=</varname>. It is only used for VTI/VTI6 tunnels.</para>
 871         </listitem>
 872       </varlistentry>
 873       <varlistentry>
 874         <term><varname>Mode=</varname></term>
 875         <listitem>
 876           <para>An <literal>ip6tnl</literal> tunnel can be in one of three
 877           modes
 878           <literal>ip6ip6</literal> for IPv6 over IPv6,
 879           <literal>ipip6</literal> for IPv4 over IPv6 or
 880           <literal>any</literal> for either.
 881           </para>
 882         </listitem>
 883       </varlistentry>
 884       <varlistentry>
 885         <term><varname>Independent=</varname></term>
 886         <listitem>
 887           <para>A boolean. When true tunnel does not require .network file. Created as "tunnel@NONE".
 888           Defaults to <literal>false</literal>.
 889           </para>
 890         </listitem>
 891       </varlistentry>
 892       <varlistentry>
 893         <term><varname>AllowLocalRemote=</varname></term>
 894         <listitem>
 895           <para>A boolean. When true allows tunnel traffic on <varname>ip6tnl</varname> devices where the remote endpoint is a local host address.
 896           Defaults to unset.
 897           </para>
 898         </listitem>
 899       </varlistentry>
 900     </variablelist>
 901   </refsect1>
 902   <refsect1>
 903     <title>[Peer] Section Options</title>
 904
 905       <para>The <literal>[Peer]</literal> section only applies for
 906       netdevs of kind <literal>veth</literal> and accepts the
 907       following keys:</para>
 908
 909       <variablelist class='network-directives'>
 910         <varlistentry>
 911           <term><varname>Name=</varname></term>
 912           <listitem>
 913             <para>The interface name used when creating the netdev.
 914             This option is compulsory.</para>
 915           </listitem>
 916         </varlistentry>
 917         <varlistentry>
 918           <term><varname>MACAddress=</varname></term>
 919           <listitem>
 920             <para>The peer MACAddress, if not set, it is generated in
 921             the same way as the MAC address of the main
 922             interface.</para>
 923           </listitem>
 924         </varlistentry>
 925       </variablelist>
 926   </refsect1>
 927   <refsect1>
 928   <title>[VXCAN] Section Options</title>
 929       <para>The <literal>[VXCAN]</literal> section only applies for
 930       netdevs of kind <literal>vxcan</literal> and accepts the
 931       following key:</para>
 932
 933       <variablelist class='network-directives'>
 934         <varlistentry>
 935           <term><varname>Peer=</varname></term>
 936           <listitem>
 937             <para>The peer interface name used when creating the netdev.
 938             This option is compulsory.</para>
 939           </listitem>
 940         </varlistentry>
 941       </variablelist>
 942   </refsect1>
 943   <refsect1>
 944     <title>[Tun] Section Options</title>
 945
 946     <para>The <literal>[Tun]</literal> section only applies for
 947     netdevs of kind <literal>tun</literal>, and accepts the following
 948     keys:</para>
 949
 950     <variablelist class='network-directives'>
 951       <varlistentry>
 952         <term><varname>OneQueue=</varname></term>
 953         <listitem><para>Takes a boolean argument. Configures whether
 954         all packets are queued at the device (enabled), or a fixed
 955         number of packets are queued at the device and the rest at the
 956         <literal>qdisc</literal>. Defaults to
 957         <literal>no</literal>.</para>
 958         </listitem>
 959       </varlistentry>
 960       <varlistentry>
 961         <term><varname>MultiQueue=</varname></term>
 962         <listitem><para>Takes a boolean argument. Configures whether
 963         to use multiple file descriptors (queues) to parallelize
 964         packets sending and receiving. Defaults to
 965         <literal>no</literal>.</para>
 966         </listitem>
 967       </varlistentry>
 968       <varlistentry>
 969         <term><varname>PacketInfo=</varname></term>
 970         <listitem><para>Takes a boolean argument. Configures whether
 971         packets should be prepended with four extra bytes (two flag
 972         bytes and two protocol bytes). If disabled, it indicates that
 973         the packets will be pure IP packets. Defaults to
 974         <literal>no</literal>.</para>
 975         </listitem>
 976       </varlistentry>
 977       <varlistentry>
 978         <term><varname>VNetHeader=</varname></term>
 979         <listitem><para>Takes a boolean argument. Configures
 980         IFF_VNET_HDR flag for a tap device. It allows sending
 981         and receiving larger Generic Segmentation Offload (GSO)
 982         packets. This may increase throughput significantly.
 983         Defaults to
 984         <literal>no</literal>.</para>
 985         </listitem>
 986       </varlistentry>
 987       <varlistentry>
 988         <term><varname>User=</varname></term>
 989         <listitem><para>User to grant access to the
 990         <filename>/dev/net/tun</filename> device.</para>
 991         </listitem>
 992       </varlistentry>
 993       <varlistentry>
 994         <term><varname>Group=</varname></term>
 995         <listitem><para>Group to grant access to the
 996         <filename>/dev/net/tun</filename> device.</para>
 997         </listitem>
 998       </varlistentry>
 999
1000     </variablelist>
1001
1002   </refsect1>
1003
1004   <refsect1>
1005     <title>[Tap] Section Options</title>
1006
1007     <para>The <literal>[Tap]</literal> section only applies for
1008     netdevs of kind <literal>tap</literal>, and accepts the same keys
1009     as the <literal>[Tun]</literal> section.</para>
1010   </refsect1>
1011
1012   <refsect1>
1013     <title>[Bond] Section Options</title>
1014
1015     <para>The <literal>[Bond]</literal> section accepts the following
1016     key:</para>
1017
1018     <variablelist class='network-directives'>
1019       <varlistentry>
1020         <term><varname>Mode=</varname></term>
1021         <listitem>
1022           <para>Specifies one of the bonding policies. The default is
1023           <literal>balance-rr</literal> (round robin). Possible values are
1024           <literal>balance-rr</literal>,
1025           <literal>active-backup</literal>,
1026           <literal>balance-xor</literal>,
1027           <literal>broadcast</literal>,
1028           <literal>802.3ad</literal>,
1029           <literal>balance-tlb</literal>, and
1030           <literal>balance-alb</literal>.
1031           </para>
1032         </listitem>
1033       </varlistentry>
1034
1035       <varlistentry>
1036         <term><varname>TransmitHashPolicy=</varname></term>
1037         <listitem>
1038           <para>Selects the transmit hash policy to use for slave
1039           selection in balance-xor, 802.3ad, and tlb modes. Possible
1040           values are
1041           <literal>layer2</literal>,
1042           <literal>layer3+4</literal>,
1043           <literal>layer2+3</literal>,
1044           <literal>encap2+3</literal>, and
1045           <literal>encap3+4</literal>.
1046           </para>
1047         </listitem>
1048       </varlistentry>
1049
1050       <varlistentry>
1051         <term><varname>LACPTransmitRate=</varname></term>
1052         <listitem>
1053           <para>Specifies the rate with which link partner transmits
1054           Link Aggregation Control Protocol Data Unit packets in
1055           802.3ad mode. Possible values are <literal>slow</literal>,
1056           which requests partner to transmit LACPDUs every 30 seconds,
1057           and <literal>fast</literal>, which requests partner to
1058           transmit LACPDUs every second. The default value is
1059           <literal>slow</literal>.</para>
1060         </listitem>
1061       </varlistentry>
1062
1063       <varlistentry>
1064         <term><varname>MIIMonitorSec=</varname></term>
1065         <listitem>
1066           <para>Specifies the frequency that Media Independent
1067           Interface link monitoring will occur. A value of zero
1068           disables MII link monitoring. This value is rounded down to
1069           the nearest millisecond. The default value is 0.</para>
1070         </listitem>
1071       </varlistentry>
1072
1073       <varlistentry>
1074         <term><varname>UpDelaySec=</varname></term>
1075         <listitem>
1076           <para>Specifies the delay before a link is enabled after a
1077           link up status has been detected. This value is rounded down
1078           to a multiple of MIIMonitorSec. The default value is
1079           0.</para>
1080         </listitem>
1081       </varlistentry>
1082
1083       <varlistentry>
1084         <term><varname>DownDelaySec=</varname></term>
1085         <listitem>
1086           <para>Specifies the delay before a link is disabled after a
1087           link down status has been detected. This value is rounded
1088           down to a multiple of MIIMonitorSec. The default value is
1089           0.</para>
1090         </listitem>
1091       </varlistentry>
1092
1093       <varlistentry>
1094         <term><varname>LearnPacketIntervalSec=</varname></term>
1095         <listitem>
1096           <para>Specifies the number of seconds between instances where the bonding
1097           driver sends learning packets to each slave peer switch.
1098           The valid range is 1–0x7fffffff; the default value is 1. This option
1099           has an effect only for the balance-tlb and balance-alb modes.</para>
1100         </listitem>
1101       </varlistentry>
1102
1103       <varlistentry>
1104         <term><varname>AdSelect=</varname></term>
1105         <listitem>
1106           <para>Specifies the 802.3ad aggregation selection logic to use. Possible values are
1107           <literal>stable</literal>,
1108           <literal>bandwidth</literal> and
1109           <literal>count</literal>.
1110           </para>
1111         </listitem>
1112       </varlistentry>
1113
1114       <varlistentry>
1115         <term><varname>FailOverMACPolicy=</varname></term>
1116         <listitem>
1117           <para>Specifies whether the active-backup mode should set all slaves to
1118           the same MAC address at the time of enslavement or, when enabled, to perform special handling of the
1119           bond's MAC address in accordance with the selected policy. The default policy is none.
1120           Possible values are
1121           <literal>none</literal>,
1122           <literal>active</literal> and
1123           <literal>follow</literal>.
1124           </para>
1125         </listitem>
1126       </varlistentry>
1127
1128       <varlistentry>
1129         <term><varname>ARPValidate=</varname></term>
1130         <listitem>
1131           <para>Specifies whether or not ARP probes and replies should be
1132           validated in any mode that supports ARP monitoring, or whether
1133           non-ARP traffic should be filtered (disregarded) for link
1134           monitoring purposes. Possible values are
1135           <literal>none</literal>,
1136           <literal>active</literal>,
1137           <literal>backup</literal> and
1138           <literal>all</literal>.
1139           </para>
1140         </listitem>
1141       </varlistentry>
1142
1143       <varlistentry>
1144         <term><varname>ARPIntervalSec=</varname></term>
1145         <listitem>
1146           <para>Specifies the ARP link monitoring frequency in milliseconds.
1147           A value of 0 disables ARP monitoring. The default value is 0.
1148           </para>
1149         </listitem>
1150       </varlistentry>
1151
1152       <varlistentry>
1153         <term><varname>ARPIPTargets=</varname></term>
1154         <listitem>
1155           <para>Specifies the IP addresses to use as ARP monitoring peers when
1156           ARPIntervalSec is greater than 0. These are the targets of the ARP request
1157           sent to determine the health of the link to the targets.
1158           Specify these values in IPv4 dotted decimal format. At least one IP
1159           address must be given for ARP monitoring to function. The
1160           maximum number of targets that can be specified is 16. The
1161           default value is no IP addresses.
1162           </para>
1163         </listitem>
1164       </varlistentry>
1165
1166       <varlistentry>
1167         <term><varname>ARPAllTargets=</varname></term>
1168         <listitem>
1169           <para>Specifies the quantity of ARPIPTargets that must be reachable
1170           in order for the ARP monitor to consider a slave as being up.
1171           This option affects only active-backup mode for slaves with
1172           ARPValidate enabled. Possible values are
1173           <literal>any</literal> and
1174           <literal>all</literal>.
1175           </para>
1176         </listitem>
1177       </varlistentry>
1178
1179       <varlistentry>
1180         <term><varname>PrimaryReselectPolicy=</varname></term>
1181         <listitem>
1182           <para>Specifies the reselection policy for the primary slave.  This
1183           affects how the primary slave is chosen to become the active slave
1184           when failure of the active slave or recovery of the primary slave
1185           occurs. This option is designed to prevent flip-flopping between
1186           the primary slave and other slaves.  Possible values are
1187           <literal>always</literal>,
1188           <literal>better</literal> and
1189           <literal>failure</literal>.
1190           </para>
1191         </listitem>
1192       </varlistentry>
1193
1194       <varlistentry>
1195         <term><varname>ResendIGMP=</varname></term>
1196         <listitem>
1197           <para>Specifies the number of IGMP membership reports to be issued after
1198           a failover event. One membership report is issued immediately after
1199           the failover, subsequent packets are sent in each 200ms interval.
1200           The valid range is 0–255. Defaults to 1. A value of 0
1201           prevents the IGMP membership report from being issued in response
1202           to the failover event.
1203           </para>
1204         </listitem>
1205       </varlistentry>
1206
1207       <varlistentry>
1208         <term><varname>PacketsPerSlave=</varname></term>
1209         <listitem>
1210           <para>Specify the number of packets to transmit through a slave before
1211             moving to the next one. When set to 0, then a slave is chosen at
1212             random. The valid range is 0–65535. Defaults to 1. This option
1213             only has effect when in balance-rr mode.
1214           </para>
1215         </listitem>
1216       </varlistentry>
1217
1218       <varlistentry>
1219         <term><varname>GratuitousARP=</varname></term>
1220         <listitem>
1221           <para>Specify the number of peer notifications (gratuitous ARPs and
1222             unsolicited IPv6 Neighbor Advertisements) to be issued after a
1223             failover event.  As soon as the link is up on the new slave,
1224             a peer notification is sent on the  bonding device and each
1225             VLAN sub-device.  This is repeated at each link monitor interval
1226             (ARPIntervalSec or MIIMonitorSec, whichever is active) if the number is
1227             greater than 1. The valid range is 0–255. The default value is 1.
1228             These options affect only the active-backup mode.
1229           </para>
1230         </listitem>
1231       </varlistentry>
1232
1233       <varlistentry>
1234         <term><varname>AllSlavesActive=</varname></term>
1235         <listitem>
1236           <para>A boolean. Specifies that duplicate frames (received on inactive ports)
1237           should be dropped when false, or delivered when true. Normally, bonding will drop
1238           duplicate frames (received on inactive ports), which is desirable for
1239           most users. But there are some times it is nice to allow duplicate
1240           frames to be delivered. The default value is false (drop duplicate frames
1241           received on inactive ports).
1242           </para>
1243         </listitem>
1244       </varlistentry>
1245
1246       <varlistentry>
1247         <term><varname>MinLinks=</varname></term>
1248         <listitem>
1249           <para>Specifies the minimum number of links that must be active before
1250           asserting carrier. The default value is 0.
1251           </para>
1252         </listitem>
1253       </varlistentry>
1254     </variablelist>
1255
1256     <para>For more detail information see
1257     <ulink url="https://www.kernel.org/doc/Documentation/networking/bonding.txt">
1258     Linux Ethernet Bonding Driver HOWTO</ulink></para>
1259
1260   </refsect1>
1261
1262   <refsect1>
1263     <title>Example</title>
1264     <example>
1265       <title>/etc/systemd/network/25-bridge.netdev</title>
1266
1267       <programlisting>[NetDev]
1268 Name=bridge0
1269 Kind=bridge</programlisting>
1270     </example>
1271
1272     <example>
1273       <title>/etc/systemd/network/25-vlan1.netdev</title>
1274
1275       <programlisting>[Match]
1276 Virtualization=no
1277
1278 [NetDev]
1279 Name=vlan1
1280 Kind=vlan
1281
1282 [VLAN]
1283 Id=1</programlisting>
1284     </example>
1285     <example>
1286       <title>/etc/systemd/network/25-ipip.netdev</title>
1287       <programlisting>[NetDev]
1288 Name=ipip-tun
1289 Kind=ipip
1290 MTUBytes=1480
1291
1292 [Tunnel]
1293 Local=192.168.223.238
1294 Remote=192.169.224.239
1295 TTL=64</programlisting>
1296     </example>
1297     <example>
1298       <title>/etc/systemd/network/25-tap.netdev</title>
1299       <programlisting>[NetDev]
1300 Name=tap-test
1301 Kind=tap
1302
1303 [Tap]
1304 MultiQueue=true
1305 PacketInfo=true</programlisting> </example>
1306
1307     <example>
1308       <title>/etc/systemd/network/25-sit.netdev</title>
1309       <programlisting>[NetDev]
1310 Name=sit-tun
1311 Kind=sit
1312 MTUBytes=1480
1313
1314 [Tunnel]
1315 Local=10.65.223.238
1316 Remote=10.65.223.239</programlisting>
1317     </example>
1318
1319     <example>
1320       <title>/etc/systemd/network/25-gre.netdev</title>
1321       <programlisting>[NetDev]
1322 Name=gre-tun
1323 Kind=gre
1324 MTUBytes=1480
1325
1326 [Tunnel]
1327 Local=10.65.223.238
1328 Remote=10.65.223.239</programlisting>
1329     </example>
1330
1331     <example>
1332       <title>/etc/systemd/network/25-vti.netdev</title>
1333
1334       <programlisting>[NetDev]
1335 Name=vti-tun
1336 Kind=vti
1337 MTUBytes=1480
1338
1339 [Tunnel]
1340 Local=10.65.223.238
1341 Remote=10.65.223.239</programlisting>
1342     </example>
1343
1344     <example>
1345       <title>/etc/systemd/network/25-veth.netdev</title>
1346       <programlisting>[NetDev]
1347 Name=veth-test
1348 Kind=veth
1349
1350 [Peer]
1351 Name=veth-peer</programlisting>
1352     </example>
1353
1354     <example>
1355       <title>/etc/systemd/network/25-bond.netdev</title>
1356       <programlisting>[NetDev]
1357 Name=bond1
1358 Kind=bond
1359
1360 [Bond]
1361 Mode=802.3ad
1362 TransmitHashPolicy=layer3+4
1363 MIIMonitorSec=1s
1364 LACPTransmitRate=fast
1365 </programlisting>
1366     </example>
1367
1368     <example>
1369       <title>/etc/systemd/network/25-dummy.netdev</title>
1370       <programlisting>[NetDev]
1371 Name=dummy-test
1372 Kind=dummy
1373 MACAddress=12:34:56:78:9a:bc</programlisting>
1374     </example>
1375     <example>
1376       <title>/etc/systemd/network/25-vrf.netdev</title>
1377       <para>Create a VRF interface with table 42.</para>
1378       <programlisting>[NetDev]
1379 Name=vrf-test
1380 Kind=vrf
1381
1382 [VRF]
1383 Table=42</programlisting>
1384     </example>
1385
1386     <example>
1387       <title>/etc/systemd/network/25-macvtap.netdev</title>
1388       <para>Create a MacVTap device.</para>
1389       <programlisting>[NetDev]
1390 Name=macvtap-test
1391 Kind=macvtap
1392       </programlisting>
1393     </example>
1394   </refsect1>
1395   <refsect1>
1396     <title>See Also</title>
1397     <para>
1398       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1399       <citerefentry><refentrytitle>systemd-networkd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
1400       <citerefentry><refentrytitle>systemd.link</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1401       <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>
1402     </para>
1403   </refsect1>
1404
1405 </refentry>