1<?xml version='1.0'?> <!--*-nxml-*-->
2<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
3  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
4<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
5
6<refentry id="systemd.netdev" conditional='ENABLE_NETWORKD'
7          xmlns:xi="http://www.w3.org/2001/XInclude">
8
9  <refentryinfo>
10    <title>systemd.network</title>
11    <productname>systemd</productname>
12  </refentryinfo>
13
14  <refmeta>
15    <refentrytitle>systemd.netdev</refentrytitle>
16    <manvolnum>5</manvolnum>
17  </refmeta>
18
19  <refnamediv>
20    <refname>systemd.netdev</refname>
21    <refpurpose>Virtual Network Device configuration</refpurpose>
22  </refnamediv>
23
24  <refsynopsisdiv>
25    <para><filename><replaceable>netdev</replaceable>.netdev</filename></para>
26  </refsynopsisdiv>
27
28  <refsect1>
29    <title>Description</title>
30
31    <para>A plain ini-style text file that encodes configuration about a virtual network device, used by
32    <citerefentry><refentrytitle>systemd-networkd</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
33    See <citerefentry><refentrytitle>systemd.syntax</refentrytitle><manvolnum>7</manvolnum></citerefentry>
34    for a general description of the syntax.</para>
35
36    <para>The main Virtual Network Device file must have the extension <filename>.netdev</filename>;
37    other extensions are ignored. Virtual network devices are created as soon as networkd is
38    started. If a netdev with the specified name already exists, networkd will use that as-is rather
39    than create its own. Note that the settings of the pre-existing netdev will not be changed by
40    networkd.</para>
41
42    <para>The <filename>.netdev</filename> files are read from the files located in the system network
43    directory <filename>/usr/lib/systemd/network</filename> and
44    <filename>/usr/local/lib/systemd/network</filename>, the volatile runtime network directory
45    <filename>/run/systemd/network</filename> and the local administration network directory
46    <filename>/etc/systemd/network</filename>. All configuration files are collectively sorted and
47    processed in alphanumeric order, regardless of the directories in which they live. However, files
48    with identical filenames replace each other. It is recommended that each filename is prefixed with
49    a number (e.g. <filename>10-vlan.netdev</filename>). Otherwise, <filename>.netdev</filename> files
50    generated by
51    <citerefentry><refentrytitle>systemd-network-generator.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
52    may take precedence over user configured files. Files in <filename>/etc/</filename> have the
53    highest priority, files in <filename>/run/</filename> take precedence over files with the same name
54    in <filename>/usr/lib/</filename>. This can be used to override a system-supplied configuration
55    file with a local file if needed. As a special case, an empty file (file size 0) or symlink with
56    the same name pointing to <filename>/dev/null</filename> disables the configuration file entirely
57    (it is "masked").</para>
58
59    <para>Along with the netdev file <filename>foo.netdev</filename>, a "drop-in" directory
60    <filename>foo.netdev.d/</filename> may exist. All files with the suffix <literal>.conf</literal>
61    from this directory will be merged in the alphanumeric order and parsed after the main file itself
62    has been parsed. This is useful to alter or add configuration settings, without having to modify
63    the main configuration file. Each drop-in file must have appropriate section headers.</para>
64
65    <para>In addition to <filename>/etc/systemd/network</filename>, drop-in <literal>.d</literal>
66    directories can be placed in <filename>/usr/lib/systemd/network</filename> or
67    <filename>/run/systemd/network</filename> directories. Drop-in files in
68    <filename>/etc/</filename> take precedence over those in <filename>/run/</filename> which in turn
69    take precedence over those in <filename>/usr/lib/</filename>. Drop-in files under any of these
70    directories take precedence over the main netdev file wherever located. (Of course, since
71    <filename>/run/</filename> is temporary and <filename>/usr/lib/</filename> is for vendors, it is
72    unlikely drop-ins should be used in either of those places.)</para>
73  </refsect1>
74
75  <refsect1>
76    <title>Supported netdev kinds</title>
77
78    <para>The following kinds of virtual network devices may be
79    configured in <filename>.netdev</filename> files:</para>
80
81    <table>
82      <title>Supported kinds of virtual network devices</title>
83
84      <tgroup cols='2'>
85        <colspec colname='kind' />
86        <colspec colname='explanation' />
87        <thead><row>
88          <entry>Kind</entry>
89          <entry>Description</entry>
90        </row></thead>
91        <tbody>
92          <row><entry><varname>bond</varname></entry>
93          <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.</entry></row>
94
95          <row><entry><varname>bridge</varname></entry>
96          <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>
97
98          <row><entry><varname>dummy</varname></entry>
99          <entry>A dummy device drops all packets sent to it.</entry></row>
100
101          <row><entry><varname>gre</varname></entry>
102          <entry>A Level 3 GRE tunnel over IPv4. See <ulink url="https://tools.ietf.org/html/rfc2784">RFC 2784</ulink> for details. Name <literal>gre0</literal> should not be used, as the kernel creates a device with this name when the corresponding kernel module is loaded.</entry></row>
103
104          <row><entry><varname>gretap</varname></entry>
105          <entry>A Level 2 GRE tunnel over IPv4. Name <literal>gretap0</literal> should not be used, as the kernel creates a device with this name when the corresponding kernel module is loaded.</entry></row>
106
107          <row><entry><varname>erspan</varname></entry>
108          <entry>ERSPAN mirrors traffic on one or more source ports and delivers the mirrored traffic to one or more destination ports on another switch. The traffic is encapsulated in generic routing encapsulation (GRE) and is therefore routable across a layer 3 network between the source switch and the destination switch. Name <literal>erspan0</literal> should not be used, as the kernel creates a device with this name when the corresponding kernel module is loaded.</entry></row>
109
110          <row><entry><varname>ip6gre</varname></entry>
111          <entry>A Level 3 GRE tunnel over IPv6.</entry></row>
112
113          <row><entry><varname>ip6tnl</varname></entry>
114          <entry>An IPv4 or IPv6 tunnel over IPv6</entry></row>
115
116          <row><entry><varname>ip6gretap</varname></entry>
117          <entry>A Level 2 GRE tunnel over IPv6.</entry></row>
118
119          <row><entry><varname>ipip</varname></entry>
120          <entry>An IPv4 over IPv4 tunnel.</entry></row>
121
122          <row><entry><varname>ipvlan</varname></entry>
123          <entry>An IPVLAN device is a stacked device which receives packets from its underlying device based on IP address filtering.</entry></row>
124
125          <row><entry><varname>ipvtap</varname></entry>
126          <entry>An IPVTAP device is a stacked device which receives packets from its underlying device based on IP address filtering and can be accessed using the tap user space interface.</entry></row>
127
128          <row><entry><varname>macvlan</varname></entry>
129          <entry>A macvlan device is a stacked device which receives packets from its underlying device based on MAC address filtering.</entry></row>
130
131          <row><entry><varname>macvtap</varname></entry>
132          <entry>A macvtap device is a stacked device which receives packets from its underlying device based on MAC address filtering.</entry></row>
133
134          <row><entry><varname>sit</varname></entry>
135          <entry>An IPv6 over IPv4 tunnel.</entry></row>
136
137          <row><entry><varname>tap</varname></entry>
138          <entry>A persistent Level 2 tunnel between a network device and a device node.</entry></row>
139
140          <row><entry><varname>tun</varname></entry>
141          <entry>A persistent Level 3 tunnel between a network device and a device node.</entry></row>
142
143          <row><entry><varname>veth</varname></entry>
144          <entry>An Ethernet tunnel between a pair of network devices.</entry></row>
145
146          <row><entry><varname>vlan</varname></entry>
147          <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>
148
149          <row><entry><varname>vti</varname></entry>
150          <entry>An IPv4 over IPSec tunnel.</entry></row>
151
152          <row><entry><varname>vti6</varname></entry>
153          <entry>An IPv6 over IPSec tunnel.</entry></row>
154
155          <row><entry><varname>vxlan</varname></entry>
156          <entry>A virtual extensible LAN (vxlan), for connecting Cloud computing deployments.</entry></row>
157
158          <row><entry><varname>geneve</varname></entry>
159          <entry>A GEneric NEtwork Virtualization Encapsulation (GENEVE) netdev driver.</entry></row>
160
161          <row><entry><varname>l2tp</varname></entry>
162          <entry>A Layer 2 Tunneling Protocol (L2TP) is a tunneling protocol used to support virtual private networks (VPNs) or as part of the delivery of services by ISPs. It does not provide any encryption or confidentiality by itself</entry></row>
163
164          <row><entry><varname>macsec</varname></entry>
165          <entry>Media Access Control Security (MACsec) is an 802.1AE IEEE industry-standard security technology that provides secure communication for all traffic on Ethernet links. MACsec provides point-to-point security on Ethernet links between directly connected nodes and is capable of identifying and preventing most security threats.</entry></row>
166
167          <row><entry><varname>vrf</varname></entry>
168          <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>
169
170          <row><entry><varname>vcan</varname></entry>
171          <entry>The virtual CAN driver (vcan). Similar to the network loopback devices, vcan offers a virtual local CAN interface.</entry></row>
172
173          <row><entry><varname>vxcan</varname></entry>
174          <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.
175          </entry></row>
176
177          <row><entry><varname>wireguard</varname></entry>
178          <entry>WireGuard Secure Network Tunnel.</entry></row>
179
180          <row><entry><varname>nlmon</varname></entry>
181          <entry>A Netlink monitor device. Use an nlmon device when you want to monitor system Netlink messages.</entry></row>
182
183          <row><entry><varname>fou</varname></entry>
184          <entry>Foo-over-UDP tunneling.</entry></row>
185
186          <row><entry><varname>xfrm</varname></entry>
187          <entry>A virtual tunnel interface like vti/vti6 but with several advantages.</entry></row>
188
189          <row><entry><varname>ifb</varname></entry>
190          <entry>The Intermediate Functional Block (ifb) pseudo network interface acts as a QoS concentrator for multiple different sources of traffic.</entry></row>
191
192          <row><entry><varname>bareudp</varname></entry>
193          <entry>Bare UDP tunnels provide a generic L3 encapsulation support for tunnelling different L3 protocols like MPLS, IP etc. inside of an UDP tunnel.</entry></row>
194
195          <row><entry><varname>batadv</varname></entry>
196          <entry><ulink url="https://www.open-mesh.org/projects/open-mesh/wiki">B.A.T.M.A.N. Advanced</ulink> is a routing protocol for multi-hop mobile ad-hoc networks which operates on layer 2.</entry></row>
197
198          <row><entry><varname>ipoib</varname></entry>
199          <entry>An IP over Infiniband subinterface.</entry></row>
200
201          <row><entry><varname>wlan</varname></entry>
202          <entry>A virtual wireless network (WLAN) interface.</entry></row>
203        </tbody>
204      </tgroup>
205    </table>
206
207  </refsect1>
208
209  <refsect1>
210    <title>[Match] Section Options</title>
211
212    <para>A virtual network device is only created if the [Match] section matches the current
213    environment, or if the section is empty. The following keys are accepted:</para>
214
215    <variablelist class='network-directives'>
216      <xi:include href="systemd.link.xml" xpointer="host" />
217      <xi:include href="systemd.link.xml" xpointer="virtualization" />
218      <xi:include href="systemd.link.xml" xpointer="kernel-command-line" />
219      <xi:include href="systemd.link.xml" xpointer="kernel-version" />
220      <xi:include href="systemd.link.xml" xpointer="architecture" />
221      <xi:include href="systemd.link.xml" xpointer="firmware" />
222    </variablelist>
223  </refsect1>
224
225  <refsect1>
226    <title>[NetDev] Section Options</title>
227
228    <para>The [NetDev] section accepts the
229    following keys:</para>
230
231    <variablelist class='network-directives'>
232      <varlistentry>
233        <term><varname>Description=</varname></term>
234        <listitem>
235          <para>A free-form description of the netdev.</para>
236        </listitem>
237      </varlistentry>
238      <varlistentry>
239        <term><varname>Name=</varname></term>
240        <listitem>
241          <para>The interface name used when creating the netdev.
242          This setting is compulsory.</para>
243        </listitem>
244      </varlistentry>
245      <varlistentry>
246        <term><varname>Kind=</varname></term>
247        <listitem>
248          <para>The netdev kind. This setting is compulsory. See the
249          <literal>Supported netdev kinds</literal> section for the
250          valid keys.</para>
251        </listitem>
252      </varlistentry>
253      <varlistentry>
254        <term><varname>MTUBytes=</varname></term>
255        <listitem>
256          <para>The maximum transmission unit in bytes to set for the device. The usual suffixes K, M, G
257          are supported and are understood to the base of 1024. For <literal>tun</literal> or
258          <literal>tap</literal> devices, <varname>MTUBytes=</varname> setting is not currently supported in
259          [NetDev] section. Please specify it in [Link] section of
260          corresponding
261          <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>
262          files.</para>
263        </listitem>
264      </varlistentry>
265      <varlistentry>
266        <term><varname>MACAddress=</varname></term>
267        <listitem>
268          <para>Specifies the MAC address to use for the device, or takes the special value
269          <literal>none</literal>. When <literal>none</literal>, <command>systemd-networkd</command>
270          does not request the MAC address for the device, and the kernel will assign a random MAC
271          address. For <literal>tun</literal>, <literal>tap</literal>, or <literal>l2tp</literal>
272          devices, the <varname>MACAddress=</varname> setting in the [NetDev] section is not
273          supported and will be ignored. Please specify it in the [Link] section of the corresponding
274          <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>
275          file. If this option is not set, <literal>vlan</literal> device inherits the MAC address of
276          the master interface. For other kind of netdevs, if this option is not set, then the MAC
277          address is generated based on the interface name and the
278          <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
279          </para>
280          <para>Note, even if <literal>none</literal> is specified, <command>systemd-udevd</command>
281          will assign the persistent MAC address for the device, as <filename>99-default.link</filename>
282          has <varname>MACAddressPolicy=persistent</varname>. So, it is also necessary to create a
283          custom .link file for the device, if the MAC address assignment is not desired.</para>
284        </listitem>
285      </varlistentry>
286    </variablelist>
287  </refsect1>
288
289  <refsect1>
290    <title>[Bridge] Section Options</title>
291
292    <para>The [Bridge] section only applies for
293    netdevs of kind <literal>bridge</literal>, and accepts the
294    following keys:</para>
295
296    <variablelist class='network-directives'>
297      <varlistentry>
298        <term><varname>HelloTimeSec=</varname></term>
299        <listitem>
300          <para>HelloTimeSec specifies the number of seconds between two hello packets
301          sent out by the root bridge and the designated bridges. Hello packets are
302          used to communicate information about the topology throughout the entire
303          bridged local area network.</para>
304        </listitem>
305      </varlistentry>
306      <varlistentry>
307        <term><varname>MaxAgeSec=</varname></term>
308        <listitem>
309          <para>MaxAgeSec specifies the number of seconds of maximum message age.
310          If the last seen (received) hello packet is more than this number of
311          seconds old, the bridge in question will start the takeover procedure
312          in attempt to become the Root Bridge itself.</para>
313        </listitem>
314      </varlistentry>
315      <varlistentry>
316        <term><varname>ForwardDelaySec=</varname></term>
317        <listitem>
318          <para>ForwardDelaySec specifies the number of seconds spent in each
319          of the Listening and Learning states before the Forwarding state is entered.</para>
320        </listitem>
321      </varlistentry>
322      <varlistentry>
323        <term><varname>AgeingTimeSec=</varname></term>
324        <listitem>
325          <para>This specifies the number of seconds a MAC Address will be kept in
326          the forwarding database after having a packet received from this MAC Address.</para>
327        </listitem>
328      </varlistentry>
329      <varlistentry>
330        <term><varname>Priority=</varname></term>
331        <listitem>
332          <para>The priority of the bridge. An integer between 0 and 65535. A lower value
333          means higher priority. The bridge having the lowest priority will be elected as root bridge.</para>
334        </listitem>
335      </varlistentry>
336      <varlistentry>
337        <term><varname>GroupForwardMask=</varname></term>
338        <listitem>
339          <para>A 16-bit bitmask represented as an integer which allows forwarding of link
340          local frames with 802.1D reserved addresses (01:80:C2:00:00:0X). A logical AND
341          is performed between the specified bitmask and the exponentiation of 2^X, the
342          lower nibble of the last octet of the MAC address. For example, a value of 8
343          would allow forwarding of frames addressed to 01:80:C2:00:00:03 (802.1X PAE).</para>
344        </listitem>
345      </varlistentry>
346      <varlistentry>
347        <term><varname>DefaultPVID=</varname></term>
348        <listitem>
349          <para>This specifies the default port VLAN ID of a newly attached bridge port.
350          Set this to an integer in the range 1…4094 or <literal>none</literal> to disable the PVID.</para>
351        </listitem>
352      </varlistentry>
353      <varlistentry>
354        <term><varname>MulticastQuerier=</varname></term>
355        <listitem>
356          <para>Takes a boolean. This setting controls the IFLA_BR_MCAST_QUERIER option in the kernel.
357          If enabled, the kernel will send general ICMP queries from a zero source address.
358          This feature should allow faster convergence on startup, but it causes some
359          multicast-aware switches to misbehave and disrupt forwarding of multicast packets.
360          When unset, the kernel's default will be used.
361          </para>
362        </listitem>
363      </varlistentry>
364      <varlistentry>
365        <term><varname>MulticastSnooping=</varname></term>
366        <listitem>
367          <para>Takes a boolean. This setting controls the IFLA_BR_MCAST_SNOOPING option in the kernel.
368          If enabled, IGMP snooping monitors the Internet Group Management Protocol (IGMP) traffic
369          between hosts and multicast routers. When unset, the kernel's default will be used.
370          </para>
371        </listitem>
372      </varlistentry>
373      <varlistentry>
374        <term><varname>VLANFiltering=</varname></term>
375        <listitem>
376          <para>Takes a boolean. This setting controls the IFLA_BR_VLAN_FILTERING option in the kernel.
377          If enabled, the bridge will be started in VLAN-filtering mode. When unset, the kernel's default will be used.
378          </para>
379        </listitem>
380      </varlistentry>
381      <varlistentry>
382        <term><varname>VLANProtocol=</varname></term>
383        <listitem>
384          <para>Allows setting the protocol used for VLAN filtering. Takes
385          <option>802.1q</option> or,
386          <option>802.1ad</option>, and defaults to unset and kernel's default is used.
387          </para>
388        </listitem>
389      </varlistentry>
390      <varlistentry>
391        <term><varname>STP=</varname></term>
392        <listitem>
393          <para>Takes a boolean. This enables the bridge's Spanning Tree Protocol (STP).
394          When unset, the kernel's default will be used.
395          </para>
396        </listitem>
397      </varlistentry>
398      <varlistentry>
399        <term><varname>MulticastIGMPVersion=</varname></term>
400        <listitem>
401          <para>Allows changing bridge's multicast Internet Group Management Protocol (IGMP) version.
402          Takes an integer 2 or 3. When unset, the kernel's default will be used.
403          </para>
404        </listitem>
405      </varlistentry>
406    </variablelist>
407  </refsect1>
408
409  <refsect1>
410    <title>[VLAN] Section Options</title>
411
412    <para>The [VLAN] section only applies for
413    netdevs of kind <literal>vlan</literal>, and accepts the
414    following key:</para>
415
416    <variablelist class='network-directives'>
417      <varlistentry>
418        <term><varname>Id=</varname></term>
419        <listitem>
420          <para>The VLAN ID to use. An integer in the range 0…4094.
421          This setting is compulsory.</para>
422        </listitem>
423      </varlistentry>
424      <varlistentry>
425        <term><varname>Protocol=</varname></term>
426        <listitem>
427          <para>Allows setting the protocol used for the VLAN interface. Takes <literal>802.1q</literal> or,
428          <literal>802.1ad</literal>, and defaults to unset and kernel's default is used.</para>
429        </listitem>
430      </varlistentry>
431      <varlistentry>
432        <term><varname>GVRP=</varname></term>
433        <listitem>
434          <para>Takes a boolean. The Generic VLAN Registration Protocol (GVRP) is a protocol that
435          allows automatic learning of VLANs on a network.
436          When unset, the kernel's default will be used.
437          </para>
438        </listitem>
439      </varlistentry>
440      <varlistentry>
441        <term><varname>MVRP=</varname></term>
442        <listitem>
443          <para>Takes a boolean. 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. When unset, the kernel's default will be used.
447          </para>
448        </listitem>
449      </varlistentry>
450      <varlistentry>
451        <term><varname>LooseBinding=</varname></term>
452        <listitem>
453          <para>Takes a boolean. 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          When unset, the kernel's default will be used.</para>
456        </listitem>
457      </varlistentry>
458      <varlistentry>
459        <term><varname>ReorderHeader=</varname></term>
460        <listitem>
461          <para>Takes a boolean. When enabled, the VLAN reorder header is used and VLAN interfaces behave
462          like physical interfaces. When unset, the kernel's default will be used.</para>
463        </listitem>
464      </varlistentry>
465      <varlistentry>
466        <term><varname>EgressQOSMaps=</varname></term>
467        <term><varname>IngressQOSMaps=</varname></term>
468        <listitem>
469          <para>Defines a mapping of Linux internal packet priority (<constant>SO_PRIORITY</constant>)
470          to VLAN header PCP field for outgoing and incoming frames, respectively. Takes a
471          whitespace-separated list of integer pairs, where each integer must be in the range
472          1…4294967294, in the format <literal>from</literal>-<literal>to</literal>, e.g.,
473          <literal>21-7 45-5</literal>. Note that <literal>from</literal> must be greater than or equal
474          to <literal>to</literal>. When unset, the kernel's default will be used.</para>
475        </listitem>
476      </varlistentry>
477    </variablelist>
478  </refsect1>
479
480  <refsect1>
481    <title>[MACVLAN] Section Options</title>
482
483    <para>The [MACVLAN] section only applies for
484    netdevs of kind <literal>macvlan</literal>, and accepts the
485    following key:</para>
486
487    <variablelist class='network-directives'>
488      <varlistentry>
489        <term><varname>Mode=</varname></term>
490        <listitem>
491          <para>The MACVLAN mode to use. The supported options are
492          <literal>private</literal>,
493          <literal>vepa</literal>,
494          <literal>bridge</literal>,
495          <literal>passthru</literal>, and
496          <literal>source</literal>.
497          </para>
498        </listitem>
499      </varlistentry>
500      <varlistentry>
501        <term><varname>SourceMACAddress=</varname></term>
502        <listitem>
503          <para>A whitespace-separated list of remote hardware addresses allowed on the MACVLAN. This
504          option only has an effect in source mode. Use full colon-, hyphen- or dot-delimited
505          hexadecimal. This option may appear more than once, in which case the lists are merged. If
506          the empty string is assigned to this option, the list of hardware addresses defined prior
507          to this is reset. Defaults to unset.</para>
508        </listitem>
509      </varlistentry>
510      <varlistentry>
511        <term><varname>BroadcastMulticastQueueLength=</varname></term>
512        <listitem>
513          <para>Specifies the length of the receive queue for broadcast/multicast packets. An unsigned
514          integer in the range 0…4294967294. Defaults to unset.</para>
515        </listitem>
516      </varlistentry>
517    </variablelist>
518  </refsect1>
519
520  <refsect1>
521    <title>[MACVTAP] Section Options</title>
522
523    <para>The [MACVTAP] section applies for netdevs of kind <literal>macvtap</literal> and accepts the same
524    keys as [MACVLAN].</para>
525  </refsect1>
526
527  <refsect1>
528    <title>[IPVLAN] Section Options</title>
529
530    <para>The [IPVLAN] section only applies for
531    netdevs of kind <literal>ipvlan</literal>, and accepts the
532    following key:</para>
533
534    <variablelist class='network-directives'>
535      <varlistentry>
536        <term><varname>Mode=</varname></term>
537        <listitem>
538          <para>The IPVLAN mode to use. The supported options are
539          <literal>L2</literal>,<literal>L3</literal> and <literal>L3S</literal>.
540          </para>
541        </listitem>
542      </varlistentry>
543      <varlistentry>
544        <term><varname>Flags=</varname></term>
545        <listitem>
546          <para>The IPVLAN flags to use. The supported options are
547          <literal>bridge</literal>,<literal>private</literal> and <literal>vepa</literal>.
548          </para>
549        </listitem>
550      </varlistentry>
551    </variablelist>
552  </refsect1>
553
554  <refsect1>
555    <title>[IPVTAP] Section Options</title>
556
557    <para>The [IPVTAP] section only applies for netdevs of kind <literal>ipvtap</literal> and accepts the
558    same keys as [IPVLAN].</para>
559  </refsect1>
560
561  <refsect1>
562    <title>[VXLAN] Section Options</title>
563
564    <para>The [VXLAN] section only applies for
565    netdevs of kind <literal>vxlan</literal>, and accepts the
566    following keys:</para>
567
568    <variablelist class='network-directives'>
569      <varlistentry>
570        <term><varname>VNI=</varname></term>
571        <listitem>
572          <para>The VXLAN Network Identifier (or VXLAN Segment ID). Takes a number in the range 1…16777215.</para>
573        </listitem>
574      </varlistentry>
575      <varlistentry>
576        <term><varname>Remote=</varname></term>
577        <listitem>
578          <para>Configures destination IP address.</para>
579        </listitem>
580      </varlistentry>
581      <varlistentry>
582        <term><varname>Local=</varname></term>
583        <listitem>
584          <para>Configures local IP address. It must be an address on the underlying interface of the
585          VXLAN interface, or one of the special values <literal>ipv4_link_local</literal>,
586          <literal>ipv6_link_local</literal>, <literal>dhcp4</literal>, <literal>dhcp6</literal>, and
587          <literal>slaac</literal>. If one of the special values is specified, an address which matches
588          the corresponding type on the underlying interface will be used. Defaults to unset.</para>
589        </listitem>
590      </varlistentry>
591      <varlistentry>
592        <term><varname>Group=</varname></term>
593        <listitem>
594          <para>Configures VXLAN multicast group IP address. All members of a VXLAN must use the same
595          multicast group address.</para>
596        </listitem>
597      </varlistentry>
598      <varlistentry>
599        <term><varname>TOS=</varname></term>
600        <listitem>
601          <para>The Type Of Service byte value for a vxlan interface.</para>
602        </listitem>
603      </varlistentry>
604      <varlistentry>
605        <term><varname>TTL=</varname></term>
606        <listitem>
607          <para>A fixed Time To Live N on Virtual eXtensible Local Area Network packets.
608          Takes <literal>inherit</literal> or a number in the range 0…255. 0 is a special
609          value meaning inherit the inner protocol's TTL value. <literal>inherit</literal>
610          means that it will inherit the outer protocol's TTL value.</para>
611        </listitem>
612      </varlistentry>
613      <varlistentry>
614        <term><varname>MacLearning=</varname></term>
615        <listitem>
616          <para>Takes a boolean. When true, enables dynamic MAC learning
617          to discover remote MAC addresses.</para>
618        </listitem>
619      </varlistentry>
620      <varlistentry>
621        <term><varname>FDBAgeingSec=</varname></term>
622        <listitem>
623          <para>The lifetime of Forwarding Database entry learnt by
624          the kernel, in seconds.</para>
625        </listitem>
626      </varlistentry>
627      <varlistentry>
628        <term><varname>MaximumFDBEntries=</varname></term>
629        <listitem>
630          <para>Configures maximum number of FDB entries.</para>
631        </listitem>
632      </varlistentry>
633      <varlistentry>
634        <term><varname>ReduceARPProxy=</varname></term>
635        <listitem>
636          <para>Takes a boolean. When true, bridge-connected VXLAN tunnel
637          endpoint answers ARP requests from the local bridge on behalf
638          of remote Distributed Overlay Virtual Ethernet
639          <ulink url="https://en.wikipedia.org/wiki/Distributed_Overlay_Virtual_Ethernet">
640          (DOVE)</ulink> clients. Defaults to false.</para>
641        </listitem>
642      </varlistentry>
643      <varlistentry>
644        <term><varname>L2MissNotification=</varname></term>
645        <listitem>
646          <para>Takes a boolean. When true, enables netlink LLADDR miss
647          notifications.</para>
648        </listitem>
649      </varlistentry>
650      <varlistentry>
651        <term><varname>L3MissNotification=</varname></term>
652        <listitem>
653          <para>Takes a boolean. When true, enables netlink IP address miss notifications.</para>
654        </listitem>
655      </varlistentry>
656      <varlistentry>
657        <term><varname>RouteShortCircuit=</varname></term>
658        <listitem>
659          <para>Takes a boolean. When true, route short circuiting is turned
660          on.</para>
661        </listitem>
662      </varlistentry>
663      <varlistentry>
664        <term><varname>UDPChecksum=</varname></term>
665        <listitem>
666          <para>Takes a boolean. When true, transmitting UDP checksums when doing VXLAN/IPv4 is turned on.</para>
667        </listitem>
668      </varlistentry>
669      <varlistentry>
670        <term><varname>UDP6ZeroChecksumTx=</varname></term>
671        <listitem>
672          <para>Takes a boolean. When true, sending zero checksums in VXLAN/IPv6 is turned on.</para>
673        </listitem>
674      </varlistentry>
675      <varlistentry>
676        <term><varname>UDP6ZeroChecksumRx=</varname></term>
677        <listitem>
678          <para>Takes a boolean. When true, receiving zero checksums in VXLAN/IPv6 is turned on.</para>
679        </listitem>
680      </varlistentry>
681      <varlistentry>
682        <term><varname>RemoteChecksumTx=</varname></term>
683        <listitem>
684          <para>Takes a boolean. When true, remote transmit checksum offload of VXLAN is turned on.</para>
685        </listitem>
686      </varlistentry>
687      <varlistentry>
688        <term><varname>RemoteChecksumRx=</varname></term>
689        <listitem>
690          <para>Takes a boolean. When true, remote receive checksum offload in VXLAN is turned on.</para>
691        </listitem>
692      </varlistentry>
693      <varlistentry>
694        <term><varname>GroupPolicyExtension=</varname></term>
695        <listitem>
696          <para>Takes a boolean. When true, it enables Group Policy VXLAN extension security label mechanism
697          across network peers based on VXLAN. For details about the Group Policy VXLAN, see the
698          <ulink url="https://tools.ietf.org/html/draft-smith-vxlan-group-policy">
699          VXLAN Group Policy </ulink> document. Defaults to false.</para>
700        </listitem>
701      </varlistentry>
702      <varlistentry>
703        <term><varname>GenericProtocolExtension=</varname></term>
704        <listitem>
705          <para>Takes a boolean. When true, Generic Protocol Extension extends the existing VXLAN protocol
706          to provide protocol typing, OAM, and versioning capabilities. For details about the VXLAN GPE
707          Header, see the <ulink url="https://tools.ietf.org/html/draft-ietf-nvo3-vxlan-gpe-07">
708          Generic Protocol Extension for VXLAN </ulink> document. If destination port is not specified and
709          Generic Protocol Extension is set then default port of 4790 is used. Defaults to false.</para>
710        </listitem>
711      </varlistentry>
712      <varlistentry>
713        <term><varname>DestinationPort=</varname></term>
714        <listitem>
715          <para>Configures the default destination UDP port. If the destination port is not specified then
716          Linux kernel default will be used. Set to 4789 to get the IANA assigned value.</para>
717        </listitem>
718      </varlistentry>
719      <varlistentry>
720        <term><varname>PortRange=</varname></term>
721        <listitem>
722          <para>Configures the source port range for the VXLAN. The kernel assigns the source UDP port based
723          on the flow to help the receiver to do load balancing. When this option is not set, the normal
724          range of local UDP ports is used.</para>
725        </listitem>
726      </varlistentry>
727      <varlistentry>
728        <term><varname>FlowLabel=</varname></term>
729        <listitem>
730          <para>Specifies the flow label to use in outgoing packets.
731          The valid range is 0-1048575.
732          </para>
733        </listitem>
734      </varlistentry>
735      <varlistentry>
736        <term><varname>IPDoNotFragment=</varname></term>
737        <listitem>
738          <para>Allows setting the IPv4 Do not Fragment (DF) bit in outgoing packets, or to inherit its
739          value from the IPv4 inner header. Takes a boolean value, or <literal>inherit</literal>. Set
740          to <literal>inherit</literal> if the encapsulated protocol is IPv6. When unset, the kernel's
741          default will be used.</para>
742        </listitem>
743      </varlistentry>
744      <varlistentry>
745        <term><varname>Independent=</varname></term>
746        <listitem>
747          <para>Takes a boolean. When true, the vxlan interface is created without any underlying network
748          interface. Defaults to false, which means that a .network file that requests this VXLAN interface
749          using <varname>VXLAN=</varname> is required for the VXLAN to be created.</para>
750        </listitem>
751      </varlistentry>
752    </variablelist>
753  </refsect1>
754
755  <refsect1>
756    <title>[GENEVE] Section Options</title>
757
758    <para>The [GENEVE] section only applies for
759    netdevs of kind <literal>geneve</literal>, and accepts the
760    following keys:</para>
761
762    <variablelist class='network-directives'>
763      <varlistentry>
764        <term><varname>Id=</varname></term>
765        <listitem>
766          <para>Specifies the Virtual Network Identifier (VNI) to use, a number between 0 and 16777215. This
767          field is mandatory.</para>
768        </listitem>
769      </varlistentry>
770      <varlistentry>
771        <term><varname>Remote=</varname></term>
772        <listitem>
773          <para>Specifies the unicast destination IP address to use in outgoing packets.</para>
774        </listitem>
775      </varlistentry>
776      <varlistentry>
777        <term><varname>TOS=</varname></term>
778        <listitem>
779          <para>Specifies the TOS value to use in outgoing packets. Takes a number between 1 and 255.</para>
780        </listitem>
781      </varlistentry>
782      <varlistentry>
783        <term><varname>TTL=</varname></term>
784        <listitem>
785          <para>Accepts the same values as in the [VXLAN] section, except that when unset
786          or set to 0, the kernel's default will be used, meaning that packet TTL will be set from
787          <filename>/proc/sys/net/ipv4/ip_default_ttl</filename>.</para>
788        </listitem>
789      </varlistentry>
790      <varlistentry>
791        <term><varname>UDPChecksum=</varname></term>
792        <listitem>
793          <para>Takes a boolean. When true, specifies that UDP checksum is calculated for transmitted packets
794          over IPv4.</para>
795        </listitem>
796      </varlistentry>
797      <varlistentry>
798        <term><varname>UDP6ZeroChecksumTx=</varname></term>
799        <listitem>
800          <para>Takes a boolean. When true, skip UDP checksum calculation for transmitted packets over IPv6.</para>
801        </listitem>
802      </varlistentry>
803      <varlistentry>
804        <term><varname>UDP6ZeroChecksumRx=</varname></term>
805        <listitem>
806          <para>Takes a boolean. When true, allows incoming UDP packets over IPv6 with zero checksum field.</para>
807        </listitem>
808      </varlistentry>
809      <varlistentry>
810        <term><varname>DestinationPort=</varname></term>
811        <listitem>
812          <para>Specifies destination port. Defaults to 6081. If not set or assigned the empty string, the default
813          port of 6081 is used.</para>
814        </listitem>
815      </varlistentry>
816      <varlistentry>
817        <term><varname>FlowLabel=</varname></term>
818        <listitem>
819          <para>Specifies the flow label to use in outgoing packets.</para>
820        </listitem>
821      </varlistentry>
822      <varlistentry>
823        <term><varname>IPDoNotFragment=</varname></term>
824        <listitem>
825          <para>Accepts the same key as in [VXLAN] section.</para>
826        </listitem>
827      </varlistentry>
828    </variablelist>
829  </refsect1>
830
831  <refsect1>
832    <title>[BareUDP] Section Options</title>
833
834    <para>The [BareUDP] section only applies for
835    netdevs of kind <literal>bareudp</literal>, and accepts the
836    following keys:</para>
837
838    <variablelist class='network-directives'>
839      <varlistentry>
840        <term><varname>DestinationPort=</varname></term>
841        <listitem>
842          <para>Specifies the destination UDP port (in range 1…65535). This is mandatory.</para>
843        </listitem>
844      </varlistentry>
845
846      <varlistentry>
847        <term><varname>EtherType=</varname></term>
848        <listitem>
849          <para>Specifies the L3 protocol. Takes one of <literal>ipv4</literal>, <literal>ipv6</literal>, <literal>mpls-uc</literal>
850          or <literal>mpls-mc</literal>. This is mandatory.</para>
851        </listitem>
852      </varlistentry>
853    </variablelist>
854  </refsect1>
855
856  <refsect1>
857    <title>[L2TP] Section Options</title>
858
859    <para>The [L2TP] section only applies for
860    netdevs of kind <literal>l2tp</literal>, and accepts the
861    following keys:</para>
862
863    <variablelist class='network-directives'>
864      <varlistentry>
865        <term><varname>TunnelId=</varname></term>
866        <listitem>
867          <para>Specifies the tunnel identifier. Takes an number in the range 1…4294967295. The value used
868          must match the <literal>PeerTunnelId=</literal> value being used at the peer. This setting is
869          compulsory.</para>
870        </listitem>
871      </varlistentry>
872      <varlistentry>
873        <term><varname>PeerTunnelId=</varname></term>
874        <listitem>
875          <para>Specifies the peer tunnel id. Takes a number in the range 1…4294967295. The value used must
876          match the <literal>TunnelId=</literal> value being used at the peer. This setting is compulsory.
877          </para>
878        </listitem>
879      </varlistentry>
880      <varlistentry>
881        <term><varname>Remote=</varname></term>
882        <listitem>
883          <para>Specifies the IP address of the remote peer. This setting is compulsory.</para>
884        </listitem>
885      </varlistentry>
886      <varlistentry>
887        <term><varname>Local=</varname></term>
888        <listitem>
889          <para>Specifies the IP address of a local interface. Takes an IP address, or the special
890          values <literal>auto</literal>, <literal>static</literal>, or <literal>dynamic</literal>.
891          Optionally a name of a local interface can be specified after <literal>@</literal>, e.g.
892          <literal>192.168.0.1@eth0</literal> or <literal>auto@eth0</literal>. When an address is
893          specified, then a local or specified interface must have the address, and the remote address
894          must be accessible through the local address. If <literal>auto</literal>, then one of the
895          addresses on a local or specified interface which is accessible to the remote address will be
896          used. Similarly, if <literal>static</literal> or <literal>dynamic</literal> is set, then one
897          of the static or dynamic addresses will be used. Defaults to <literal>auto</literal>.</para>
898        </listitem>
899      </varlistentry>
900      <varlistentry>
901        <term><varname>EncapsulationType=</varname></term>
902        <listitem>
903          <para>Specifies the encapsulation type of the tunnel. Takes one of <literal>udp</literal> or
904          <literal>ip</literal>.</para>
905        </listitem>
906      </varlistentry>
907      <varlistentry>
908        <term><varname>UDPSourcePort=</varname></term>
909        <listitem>
910          <para>Specifies the UDP source port to be used for the tunnel. When UDP encapsulation is selected
911          it's mandatory. Ignored when IP encapsulation is selected.</para>
912        </listitem>
913      </varlistentry>
914      <varlistentry>
915        <term><varname>UDPDestinationPort=</varname></term>
916        <listitem>
917          <para>Specifies destination port. When UDP encapsulation is selected it's mandatory. Ignored when IP
918          encapsulation is selected.</para>
919        </listitem>
920      </varlistentry>
921      <varlistentry>
922        <term><varname>UDPChecksum=</varname></term>
923        <listitem>
924          <para>Takes a boolean. When true, specifies that UDP checksum is calculated for transmitted packets
925          over IPv4.</para>
926        </listitem>
927      </varlistentry>
928      <varlistentry>
929        <term><varname>UDP6ZeroChecksumTx=</varname></term>
930        <listitem>
931          <para>Takes a boolean. When true, skip UDP checksum calculation for transmitted packets over IPv6.</para>
932        </listitem>
933      </varlistentry>
934      <varlistentry>
935        <term><varname>UDP6ZeroChecksumRx=</varname></term>
936        <listitem>
937          <para>Takes a boolean. When true, allows incoming UDP packets over IPv6 with zero checksum field.</para>
938        </listitem>
939      </varlistentry>
940    </variablelist>
941  </refsect1>
942
943  <refsect1>
944    <title>[L2TPSession] Section Options</title>
945
946    <para>The [L2TPSession] section only applies for
947    netdevs of kind <literal>l2tp</literal>, and accepts the
948    following keys:</para>
949    <variablelist class='network-directives'>
950      <varlistentry>
951        <term><varname>Name=</varname></term>
952        <listitem>
953          <para>Specifies the name of the session. This setting is compulsory.</para>
954        </listitem>
955      </varlistentry>
956      <varlistentry>
957        <term><varname>SessionId=</varname></term>
958        <listitem>
959          <para>Specifies the session identifier. Takes an number in the range 1…4294967295. The value used
960          must match the <literal>SessionId=</literal> value being used at the peer. This setting is
961          compulsory.</para>
962        </listitem>
963      </varlistentry>
964      <varlistentry>
965        <term><varname>PeerSessionId=</varname></term>
966        <listitem>
967          <para>Specifies the peer session identifier. Takes an number in the range 1…4294967295.
968          The value used must match the <literal>PeerSessionId=</literal> value being used at the peer.
969          This setting is compulsory.</para>
970        </listitem>
971      </varlistentry>
972      <varlistentry>
973        <term><varname>Layer2SpecificHeader=</varname></term>
974        <listitem>
975          <para>Specifies layer2specific header type of the session. One of <literal>none</literal> or <literal>default</literal>. Defaults to <literal>default</literal>.</para>
976        </listitem>
977      </varlistentry>
978    </variablelist>
979  </refsect1>
980
981  <refsect1>
982    <title>[MACsec] Section Options</title>
983
984    <para>The [MACsec] section only applies for network devices of kind
985    <literal>macsec</literal>, and accepts the following keys:</para>
986
987    <variablelist class='network-directives'>
988      <varlistentry>
989        <term><varname>Port=</varname></term>
990        <listitem>
991          <para>Specifies the port to be used for the MACsec transmit channel. The port is used to make
992          secure channel identifier (SCI). Takes a value between 1 and 65535. Defaults to unset.
993          </para>
994        </listitem>
995      </varlistentry>
996      <varlistentry>
997        <term><varname>Encrypt=</varname></term>
998        <listitem>
999          <para>Takes a boolean. When true, enable encryption. Defaults to unset.</para>
1000        </listitem>
1001      </varlistentry>
1002    </variablelist>
1003  </refsect1>
1004
1005  <refsect1>
1006    <title>[MACsecReceiveChannel] Section Options</title>
1007    <para>The [MACsecReceiveChannel] section only applies for network devices of
1008    kind <literal>macsec</literal>, and accepts the following keys:</para>
1009
1010    <variablelist class='network-directives'>
1011      <varlistentry>
1012        <term><varname>Port=</varname></term>
1013        <listitem>
1014          <para>Specifies the port to be used for the MACsec receive channel. The port is used to make
1015          secure channel identifier (SCI). Takes a value between 1 and 65535. This option is
1016          compulsory, and is not set by default.</para>
1017        </listitem>
1018      </varlistentry>
1019      <varlistentry>
1020        <term><varname>MACAddress=</varname></term>
1021        <listitem>
1022          <para>Specifies the MAC address to be used for the MACsec receive channel. The MAC address
1023          used to make secure channel identifier (SCI). This setting is compulsory, and is not set by
1024          default.</para>
1025        </listitem>
1026      </varlistentry>
1027    </variablelist>
1028  </refsect1>
1029
1030  <refsect1>
1031    <title>[MACsecTransmitAssociation] Section Options</title>
1032
1033    <para>The [MACsecTransmitAssociation] section only applies for network devices
1034    of kind <literal>macsec</literal>, and accepts the following keys:</para>
1035
1036    <variablelist class='network-directives'>
1037      <varlistentry>
1038        <term><varname>PacketNumber=</varname></term>
1039        <listitem>
1040          <para>Specifies the packet number to be used for replay protection and the construction of
1041          the initialization vector (along with the secure channel identifier [SCI]). Takes a value
1042          between 1-4,294,967,295. Defaults to unset.
1043          </para>
1044        </listitem>
1045      </varlistentry>
1046      <varlistentry>
1047        <term><varname>KeyId=</varname></term>
1048        <listitem>
1049          <para>Specifies the identification for the key. Takes a number between 0-255. This option
1050          is compulsory, and is not set by default.</para>
1051        </listitem>
1052      </varlistentry>
1053      <varlistentry>
1054        <term><varname>Key=</varname></term>
1055        <listitem>
1056          <para>Specifies the encryption key used in the transmission channel. The same key must be
1057          configured on the peer’s matching receive channel. This setting is compulsory, and is not set
1058          by default. Takes a 128-bit key encoded in a hexadecimal string, for example
1059          <literal>dffafc8d7b9a43d5b9a3dfbbf6a30c16</literal>.</para>
1060        </listitem>
1061      </varlistentry>
1062      <varlistentry>
1063        <term><varname>KeyFile=</varname></term>
1064        <listitem>
1065          <para>Takes an absolute path to a file which contains a 128-bit key encoded in a hexadecimal string,
1066          which will be used in the transmission channel. When this option is specified,
1067          <varname>Key=</varname> is ignored. Note that the file must be readable by the user
1068          <literal>systemd-network</literal>, so it should be, e.g., owned by
1069          <literal>root:systemd-network</literal> with a <literal>0640</literal> file mode. If the path
1070          refers to an <constant>AF_UNIX</constant> stream socket in the file system a connection is made to
1071          it and the key read from it.</para>
1072        </listitem>
1073      </varlistentry>
1074      <varlistentry>
1075        <term><varname>Activate=</varname></term>
1076        <listitem>
1077          <para>Takes a boolean. If enabled, then the security association is activated. Defaults to
1078          unset.</para>
1079        </listitem>
1080      </varlistentry>
1081      <varlistentry>
1082        <term><varname>UseForEncoding=</varname></term>
1083        <listitem>
1084          <para>Takes a boolean. If enabled, then the security association is used for encoding. Only
1085          one [MACsecTransmitAssociation] section can enable this option. When enabled,
1086          <varname>Activate=yes</varname> is implied. Defaults to unset.</para>
1087        </listitem>
1088      </varlistentry>
1089    </variablelist>
1090  </refsect1>
1091
1092  <refsect1>
1093    <title>[MACsecReceiveAssociation] Section Options</title>
1094
1095    <para>The [MACsecReceiveAssociation] section only applies for
1096    network devices of kind <literal>macsec</literal>, and accepts the
1097    following keys:</para>
1098
1099    <variablelist class='network-directives'>
1100      <varlistentry>
1101        <term><varname>Port=</varname></term>
1102        <listitem>
1103          <para>Accepts the same key as in [MACsecReceiveChannel] section.</para>
1104        </listitem>
1105      </varlistentry>
1106      <varlistentry>
1107        <term><varname>MACAddress=</varname></term>
1108        <listitem>
1109          <para>Accepts the same key as in [MACsecReceiveChannel] section.</para>
1110        </listitem>
1111      </varlistentry>
1112      <varlistentry>
1113        <term><varname>PacketNumber=</varname></term>
1114        <listitem>
1115          <para>Accepts the same key as in [MACsecTransmitAssociation] section.</para>
1116        </listitem>
1117      </varlistentry>
1118      <varlistentry>
1119        <term><varname>KeyId=</varname></term>
1120        <listitem>
1121          <para>Accepts the same key as in [MACsecTransmitAssociation] section.</para>
1122        </listitem>
1123      </varlistentry>
1124      <varlistentry>
1125        <term><varname>Key=</varname></term>
1126        <listitem>
1127          <para>Accepts the same key as in [MACsecTransmitAssociation] section.</para>
1128        </listitem>
1129      </varlistentry>
1130      <varlistentry>
1131        <term><varname>KeyFile=</varname></term>
1132        <listitem>
1133          <para>Accepts the same key as in [MACsecTransmitAssociation] section.</para>
1134        </listitem>
1135      </varlistentry>
1136      <varlistentry>
1137        <term><varname>Activate=</varname></term>
1138        <listitem>
1139          <para>Accepts the same key as in [MACsecTransmitAssociation] section.</para>
1140        </listitem>
1141      </varlistentry>
1142    </variablelist>
1143  </refsect1>
1144
1145  <refsect1>
1146    <title>[Tunnel] Section Options</title>
1147
1148    <para>The [Tunnel] section only applies for
1149    netdevs of kind
1150    <literal>ipip</literal>,
1151    <literal>sit</literal>,
1152    <literal>gre</literal>,
1153    <literal>gretap</literal>,
1154    <literal>ip6gre</literal>,
1155    <literal>ip6gretap</literal>,
1156    <literal>vti</literal>,
1157    <literal>vti6</literal>,
1158    <literal>ip6tnl</literal>, and
1159    <literal>erspan</literal> and accepts
1160    the following keys:</para>
1161
1162    <variablelist class='network-directives'>
1163      <varlistentry>
1164        <term><varname>External=</varname></term>
1165        <listitem>
1166          <para>Takes a boolean value. When true, then the tunnel is externally controlled, which is
1167          also known as collect metadata mode, and most settings below like <varname>Local=</varname>
1168          or <varname>Remote=</varname> are ignored. This implies <varname>Independent=</varname>.
1169          Defaults to false.</para>
1170        </listitem>
1171      </varlistentry>
1172      <varlistentry>
1173        <term><varname>Local=</varname></term>
1174        <listitem>
1175          <para>A static local address for tunneled packets. It must be an address on another interface
1176          of this host, or one of the special values <literal>any</literal>,
1177          <literal>ipv4_link_local</literal>, <literal>ipv6_link_local</literal>,
1178          <literal>dhcp4</literal>, <literal>dhcp6</literal>, and <literal>slaac</literal>. If one
1179          of the special values except for <literal>any</literal> is specified, an address which
1180          matches the corresponding type on the underlying interface will be used. Defaults to
1181          <literal>any</literal>.</para>
1182        </listitem>
1183      </varlistentry>
1184      <varlistentry>
1185        <term><varname>Remote=</varname></term>
1186        <listitem>
1187          <para>The remote endpoint of the tunnel. Takes an IP address or the special value
1188          <literal>any</literal>.</para>
1189        </listitem>
1190      </varlistentry>
1191      <varlistentry>
1192        <term><varname>TOS=</varname></term>
1193        <listitem>
1194          <para>The Type Of Service byte value for a tunnel interface.
1195          For details about the TOS, see the
1196          <ulink url="http://tools.ietf.org/html/rfc1349"> Type of
1197          Service in the Internet Protocol Suite </ulink> document.
1198          </para>
1199        </listitem>
1200      </varlistentry>
1201      <varlistentry>
1202        <term><varname>TTL=</varname></term>
1203        <listitem>
1204          <para>A fixed Time To Live N on tunneled packets. N is a
1205          number in the range 1…255. 0 is a special value meaning that
1206          packets inherit the TTL value. The default value for IPv4
1207          tunnels is 0 (inherit). The default value for IPv6 tunnels is
1208          64.</para>
1209        </listitem>
1210      </varlistentry>
1211      <varlistentry>
1212        <term><varname>DiscoverPathMTU=</varname></term>
1213        <listitem>
1214          <para>Takes a boolean. When true, enables Path MTU Discovery on
1215          the tunnel.</para>
1216        </listitem>
1217      </varlistentry>
1218      <varlistentry>
1219        <term><varname>IPv6FlowLabel=</varname></term>
1220        <listitem>
1221          <para>Configures the 20-bit flow label (see <ulink url="https://tools.ietf.org/html/rfc6437">
1222          RFC 6437</ulink>) field in the IPv6 header (see <ulink url="https://tools.ietf.org/html/rfc2460">
1223          RFC 2460</ulink>), which is used by a node to label packets of a flow.
1224          It is only used for IPv6 tunnels.
1225          A flow label of zero is used to indicate packets that have
1226          not been labeled.
1227          It can be configured to a value in the range 0…0xFFFFF, or be
1228          set to <literal>inherit</literal>, in which case the original flowlabel is used.</para>
1229        </listitem>
1230      </varlistentry>
1231      <varlistentry>
1232        <term><varname>CopyDSCP=</varname></term>
1233        <listitem>
1234          <para>Takes a boolean. When true, the Differentiated Service Code
1235          Point (DSCP) field will be copied to the inner header from
1236          outer header during the decapsulation of an IPv6 tunnel
1237          packet. DSCP is a field in an IP packet that enables different
1238          levels of service to be assigned to network traffic.
1239          Defaults to <literal>no</literal>.
1240          </para>
1241        </listitem>
1242      </varlistentry>
1243      <varlistentry>
1244        <term><varname>EncapsulationLimit=</varname></term>
1245        <listitem>
1246          <para>The Tunnel Encapsulation Limit option specifies how many additional
1247          levels of encapsulation are permitted to be prepended to the packet.
1248          For example, a Tunnel Encapsulation Limit option containing a limit
1249          value of zero means that a packet carrying that option may not enter
1250          another tunnel before exiting the current tunnel.
1251          (see <ulink url="https://tools.ietf.org/html/rfc2473#section-4.1.1"> RFC 2473</ulink>).
1252          The valid range is 0…255 and <literal>none</literal>. Defaults to 4.
1253        </para>
1254        </listitem>
1255      </varlistentry>
1256      <varlistentry>
1257        <term><varname>Key=</varname></term>
1258        <listitem>
1259          <para>The <varname>Key=</varname> parameter specifies the same key to use in
1260          both directions (<varname>InputKey=</varname> and <varname>OutputKey=</varname>).
1261          The <varname>Key=</varname> is either a number or an IPv4 address-like dotted quad.
1262          It is used as mark-configured SAD/SPD entry as part of the lookup key (both in data
1263          and control path) in IP XFRM (framework used to implement IPsec protocol).
1264          See <ulink url="http://man7.org/linux/man-pages/man8/ip-xfrm.8.html">
1265          ip-xfrm — transform configuration</ulink> for details. It is only used for VTI/VTI6,
1266          GRE, GRETAP, and ERSPAN tunnels.</para>
1267        </listitem>
1268      </varlistentry>
1269      <varlistentry>
1270        <term><varname>InputKey=</varname></term>
1271        <listitem>
1272          <para>The <varname>InputKey=</varname> parameter specifies the key to use for input.
1273          The format is same as <varname>Key=</varname>. It is only used for VTI/VTI6, GRE, GRETAP,
1274          and ERSPAN tunnels.</para>
1275        </listitem>
1276      </varlistentry>
1277      <varlistentry>
1278        <term><varname>OutputKey=</varname></term>
1279        <listitem>
1280          <para>The <varname>OutputKey=</varname> parameter specifies the key to use for output.
1281          The format is same as <varname>Key=</varname>. It is only used for VTI/VTI6, GRE, GRETAP,
1282          and ERSPAN tunnels.</para>
1283        </listitem>
1284      </varlistentry>
1285      <varlistentry>
1286        <term><varname>Mode=</varname></term>
1287        <listitem>
1288          <para>An <literal>ip6tnl</literal> tunnel can be in one of three
1289          modes
1290          <literal>ip6ip6</literal> for IPv6 over IPv6,
1291          <literal>ipip6</literal> for IPv4 over IPv6 or
1292          <literal>any</literal> for either.
1293          </para>
1294        </listitem>
1295      </varlistentry>
1296      <varlistentry>
1297        <term><varname>Independent=</varname></term>
1298        <listitem>
1299          <para>Takes a boolean. When false (the default), the tunnel is always created over some network
1300          device, and a .network file that requests this tunnel using <varname>Tunnel=</varname> is required
1301          for the tunnel to be created. When true, the tunnel is created independently of any network as
1302          "tunnel@NONE".</para>
1303        </listitem>
1304      </varlistentry>
1305      <varlistentry>
1306        <term><varname>AssignToLoopback=</varname></term>
1307        <listitem>
1308          <para>Takes a boolean. If set to <literal>yes</literal>, the loopback interface <literal>lo</literal>
1309          is used as the underlying device of the tunnel interface. Defaults to <literal>no</literal>.</para>
1310        </listitem>
1311      </varlistentry>
1312      <varlistentry>
1313        <term><varname>AllowLocalRemote=</varname></term>
1314        <listitem>
1315          <para>Takes a boolean. When true allows tunnel traffic on <varname>ip6tnl</varname> devices where the remote endpoint is a local host address.
1316          When unset, the kernel's default will be used.
1317          </para>
1318        </listitem>
1319      </varlistentry>
1320      <varlistentry>
1321        <term><varname>FooOverUDP=</varname></term>
1322        <listitem>
1323          <para>Takes a boolean. Specifies whether <varname>FooOverUDP=</varname> tunnel is to be configured.
1324          Defaults to false. This takes effects only for IPIP, SIT, GRE, and GRETAP tunnels.
1325          For more detail information see
1326          <ulink url="https://lwn.net/Articles/614348">Foo over UDP</ulink></para>
1327        </listitem>
1328      </varlistentry>
1329      <varlistentry>
1330        <term><varname>FOUDestinationPort=</varname></term>
1331        <listitem>
1332          <para>This setting specifies the UDP destination port for encapsulation.
1333          This field is mandatory when <varname>FooOverUDP=yes</varname>, and is not set by default.</para>
1334        </listitem>
1335      </varlistentry>
1336      <varlistentry>
1337        <term><varname>FOUSourcePort=</varname></term>
1338        <listitem>
1339          <para>This setting specifies the UDP source port for encapsulation. Defaults to <constant>0</constant>
1340          — that is, the source port for packets is left to the network stack to decide.</para>
1341        </listitem>
1342      </varlistentry>
1343      <varlistentry>
1344        <term><varname>Encapsulation=</varname></term>
1345        <listitem>
1346          <para>Accepts the same key as in the [FooOverUDP] section.</para>
1347        </listitem>
1348      </varlistentry>
1349      <varlistentry>
1350        <term><varname>IPv6RapidDeploymentPrefix=</varname></term>
1351        <listitem>
1352          <para>Reconfigure the tunnel for <ulink url="https://tools.ietf.org/html/rfc5569">IPv6 Rapid
1353          Deployment</ulink>, also known as 6rd. The value is an ISP-specific IPv6 prefix with a non-zero length. Only
1354          applicable to SIT tunnels.</para>
1355        </listitem>
1356      </varlistentry>
1357      <varlistentry>
1358        <term><varname>ISATAP=</varname></term>
1359        <listitem>
1360          <para>Takes a boolean. If set, configures the tunnel as Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) tunnel.
1361          Only applicable to SIT tunnels. When unset, the kernel's default will be used.</para>
1362        </listitem>
1363      </varlistentry>
1364      <varlistentry>
1365        <term><varname>SerializeTunneledPackets=</varname></term>
1366        <listitem>
1367          <para>Takes a boolean. If set to yes, then packets are serialized. Only applies for GRE,
1368          GRETAP, and ERSPAN tunnels. When unset, the kernel's default will be used.
1369          </para>
1370        </listitem>
1371      </varlistentry>
1372      <varlistentry>
1373        <term><varname>ERSPANIndex=</varname></term>
1374        <listitem>
1375          <para>Specifies the ERSPAN index field for the interface, an integer in the range 1…1048575 associated with
1376          the ERSPAN traffic's source port and direction. This field is mandatory.
1377          </para>
1378        </listitem>
1379      </varlistentry>
1380    </variablelist>
1381  </refsect1>
1382
1383  <refsect1>
1384    <title>[FooOverUDP] Section Options</title>
1385
1386    <para>The [FooOverUDP] section only applies for
1387    netdevs of kind <literal>fou</literal> and accepts the
1388    following keys:</para>
1389
1390    <variablelist class='network-directives'>
1391      <varlistentry>
1392        <term><varname>Encapsulation=</varname></term>
1393        <listitem>
1394          <para>Specifies the encapsulation mechanism used to store networking packets of various protocols
1395          inside the UDP packets. Supports the following values:
1396
1397          <literal>FooOverUDP</literal> provides the simplest no-frills model of UDP encapsulation, it simply
1398          encapsulates packets directly in the UDP payload. <literal>GenericUDPEncapsulation</literal> is a
1399          generic and extensible encapsulation, it allows encapsulation of packets for any IP protocol and
1400          optional data as part of the encapsulation. For more detailed information see <ulink
1401          url="https://lwn.net/Articles/615044">Generic UDP Encapsulation</ulink>. Defaults to
1402          <literal>FooOverUDP</literal>.
1403          </para>
1404        </listitem>
1405      </varlistentry>
1406      <varlistentry>
1407        <term><varname>Port=</varname></term>
1408        <listitem>
1409          <para>Specifies the port number where the encapsulated packets will arrive. Those packets will be
1410          removed and manually fed back into the network stack with the encapsulation removed to be sent to
1411          the real destination. This option is mandatory.</para>
1412        </listitem>
1413      </varlistentry>
1414      <varlistentry>
1415        <term><varname>PeerPort=</varname></term>
1416        <listitem>
1417          <para>Specifies the peer port number. Defaults to unset. Note that when peer port is set
1418          <literal>Peer=</literal> address is mandatory.</para>
1419        </listitem>
1420      </varlistentry>
1421      <varlistentry>
1422        <term><varname>Protocol=</varname></term>
1423        <listitem>
1424          <para>The <varname>Protocol=</varname> specifies the protocol number of the packets arriving
1425          at the UDP port. When <varname>Encapsulation=FooOverUDP</varname>, this field is mandatory
1426          and is not set by default. Takes an IP protocol name such as <literal>gre</literal> or
1427          <literal>ipip</literal>, or an integer within the range 1…255. When
1428          <varname>Encapsulation=GenericUDPEncapsulation</varname>, this must not be specified.</para>
1429        </listitem>
1430      </varlistentry>
1431      <varlistentry>
1432        <term><varname>Peer=</varname></term>
1433        <listitem>
1434          <para>Configures peer IP address. Note that when peer address is set <literal>PeerPort=</literal>
1435          is mandatory.</para>
1436        </listitem>
1437      </varlistentry>
1438      <varlistentry>
1439        <term><varname>Local=</varname></term>
1440        <listitem>
1441          <para>Configures local IP address.</para>
1442        </listitem>
1443      </varlistentry>
1444    </variablelist>
1445  </refsect1>
1446
1447  <refsect1>
1448    <title>[Peer] Section Options</title>
1449
1450    <para>The [Peer] section only applies for
1451    netdevs of kind <literal>veth</literal> and accepts the
1452    following keys:</para>
1453
1454    <variablelist class='network-directives'>
1455      <varlistentry>
1456        <term><varname>Name=</varname></term>
1457        <listitem>
1458          <para>The interface name used when creating the netdev.
1459          This setting is compulsory.</para>
1460        </listitem>
1461      </varlistentry>
1462      <varlistentry>
1463        <term><varname>MACAddress=</varname></term>
1464        <listitem>
1465          <para>The peer MACAddress, if not set, it is generated in
1466          the same way as the MAC address of the main
1467          interface.</para>
1468        </listitem>
1469      </varlistentry>
1470    </variablelist>
1471  </refsect1>
1472
1473  <refsect1>
1474    <title>[VXCAN] Section Options</title>
1475
1476    <para>The [VXCAN] section only applies for
1477    netdevs of kind <literal>vxcan</literal> and accepts the
1478    following key:</para>
1479
1480    <variablelist class='network-directives'>
1481      <varlistentry>
1482        <term><varname>Peer=</varname></term>
1483        <listitem>
1484          <para>The peer interface name used when creating the netdev.
1485          This setting is compulsory.</para>
1486        </listitem>
1487      </varlistentry>
1488    </variablelist>
1489  </refsect1>
1490
1491  <refsect1>
1492    <title>[Tun] Section Options</title>
1493
1494    <para>The [Tun] section only applies for
1495    netdevs of kind <literal>tun</literal>, and accepts the following
1496    keys:</para>
1497
1498    <variablelist class='network-directives'>
1499      <varlistentry>
1500        <term><varname>MultiQueue=</varname></term>
1501        <listitem><para>Takes a boolean. Configures whether
1502        to use multiple file descriptors (queues) to parallelize
1503        packets sending and receiving. Defaults to
1504        <literal>no</literal>.</para>
1505        </listitem>
1506      </varlistentry>
1507      <varlistentry>
1508        <term><varname>PacketInfo=</varname></term>
1509        <listitem><para>Takes a boolean. Configures whether
1510        packets should be prepended with four extra bytes (two flag
1511        bytes and two protocol bytes). If disabled, it indicates that
1512        the packets will be pure IP packets. Defaults to
1513        <literal>no</literal>.</para>
1514        </listitem>
1515      </varlistentry>
1516      <varlistentry>
1517        <term><varname>VNetHeader=</varname></term>
1518        <listitem><para>Takes a boolean. Configures
1519        IFF_VNET_HDR flag for a tun or tap device. It allows sending
1520        and receiving larger Generic Segmentation Offload (GSO)
1521        packets. This may increase throughput significantly.
1522        Defaults to
1523        <literal>no</literal>.</para>
1524        </listitem>
1525      </varlistentry>
1526      <varlistentry>
1527        <term><varname>User=</varname></term>
1528        <listitem><para>User to grant access to the
1529        <filename>/dev/net/tun</filename> device.</para>
1530        </listitem>
1531      </varlistentry>
1532      <varlistentry>
1533        <term><varname>Group=</varname></term>
1534        <listitem><para>Group to grant access to the
1535        <filename>/dev/net/tun</filename> device.</para>
1536        </listitem>
1537      </varlistentry>
1538    </variablelist>
1539  </refsect1>
1540
1541  <refsect1>
1542    <title>[Tap] Section Options</title>
1543
1544    <para>The [Tap] section only applies for
1545    netdevs of kind <literal>tap</literal>, and accepts the same keys
1546    as the [Tun] section.</para>
1547  </refsect1>
1548
1549  <refsect1>
1550    <title>[WireGuard] Section Options</title>
1551
1552    <para>The [WireGuard] section accepts the following
1553    keys:</para>
1554
1555    <variablelist class='network-directives'>
1556      <varlistentry>
1557        <term><varname>PrivateKey=</varname></term>
1558        <listitem>
1559          <para>The Base64 encoded private key for the interface. It can be
1560          generated using the <command>wg genkey</command> command
1561          (see <citerefentry project="wireguard"><refentrytitle>wg</refentrytitle><manvolnum>8</manvolnum></citerefentry>).
1562          This option or <varname>PrivateKeyFile=</varname> is mandatory to use WireGuard.
1563          Note that because this information is secret, you may want to set
1564          the permissions of the .netdev file to be owned by <literal>root:systemd-network</literal>
1565          with a <literal>0640</literal> file mode.</para>
1566        </listitem>
1567      </varlistentry>
1568      <varlistentry>
1569        <term><varname>PrivateKeyFile=</varname></term>
1570        <listitem>
1571          <para>Takes an absolute path to a file which contains the Base64 encoded private key for the
1572          interface.  When this option is specified, then <varname>PrivateKey=</varname> is ignored.  Note
1573          that the file must be readable by the user <literal>systemd-network</literal>, so it should be,
1574          e.g., owned by <literal>root:systemd-network</literal> with a <literal>0640</literal> file mode. If
1575          the path refers to an <constant>AF_UNIX</constant> stream socket in the file system a connection is
1576          made to it and the key read from it.</para>
1577        </listitem>
1578      </varlistentry>
1579      <varlistentry>
1580        <term><varname>ListenPort=</varname></term>
1581        <listitem>
1582          <para>Sets UDP port for listening. Takes either value between 1 and 65535
1583          or <literal>auto</literal>. If <literal>auto</literal> is specified,
1584          the port is automatically generated based on interface name.
1585          Defaults to <literal>auto</literal>.</para>
1586        </listitem>
1587      </varlistentry>
1588      <varlistentry>
1589        <term><varname>FirewallMark=</varname></term>
1590        <listitem>
1591          <para>Sets a firewall mark on outgoing WireGuard packets from this interface. Takes a number between 1 and 4294967295.</para>
1592        </listitem>
1593      </varlistentry>
1594      <varlistentry>
1595        <term><varname>RouteTable=</varname></term>
1596        <listitem>
1597          <para>The table identifier for the routes to the addresses specified in the
1598          <varname>AllowedIPs=</varname>. Takes a negative boolean value, one of the predefined names
1599          <literal>default</literal>, <literal>main</literal>, and <literal>local</literal>, names
1600          defined in <varname>RouteTable=</varname> in
1601          <citerefentry><refentrytitle>networkd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1602          or a number in the range 1…4294967295. When <literal>off</literal> the routes to the
1603          addresses specified in the <varname>AllowedIPs=</varname> setting will not be configured.
1604          Defaults to false. This setting will be ignored when the same setting is specified in the
1605          [WireGuardPeer] section.</para>
1606        </listitem>
1607      </varlistentry>
1608      <varlistentry>
1609        <term><varname>RouteMetric=</varname></term>
1610        <listitem>
1611          <para>The priority of the routes to the addresses specified in the
1612          <varname>AllowedIPs=</varname>. Takes an integer in the range 0…4294967295. Defaults to 0
1613          for IPv4 addresses, and 1024 for IPv6 addresses. This setting will be ignored when the same
1614          setting is specified in the [WireGuardPeer] section.</para>
1615        </listitem>
1616      </varlistentry>
1617    </variablelist>
1618  </refsect1>
1619
1620  <refsect1>
1621    <title>[WireGuardPeer] Section Options</title>
1622
1623    <para>The [WireGuardPeer] section accepts the following
1624    keys:</para>
1625
1626    <variablelist class='network-directives'>
1627      <varlistentry>
1628        <term><varname>PublicKey=</varname></term>
1629        <listitem>
1630          <para>Sets a Base64 encoded public key calculated by <command>wg pubkey</command>
1631          (see <citerefentry project="wireguard"><refentrytitle>wg</refentrytitle><manvolnum>8</manvolnum></citerefentry>)
1632          from a private key, and usually transmitted out of band to the
1633          author of the configuration file. This option is mandatory for this
1634          section.</para>
1635        </listitem>
1636      </varlistentry>
1637      <varlistentry>
1638        <term><varname>PresharedKey=</varname></term>
1639        <listitem>
1640          <para>Optional preshared key for the interface. It can be generated
1641          by the <command>wg genpsk</command> command. This option adds an
1642          additional layer of symmetric-key cryptography to be mixed into the
1643          already existing public-key cryptography, for post-quantum
1644          resistance.
1645          Note that because this information is secret, you may want to set
1646          the permissions of the .netdev file to be owned by <literal>root:systemd-network</literal>
1647          with a <literal>0640</literal> file mode.</para>
1648        </listitem>
1649      </varlistentry>
1650      <varlistentry>
1651        <term><varname>PresharedKeyFile=</varname></term>
1652        <listitem>
1653          <para>Takes an absolute path to a file which contains the Base64 encoded preshared key for the
1654          peer. When this option is specified, then <varname>PresharedKey=</varname> is ignored.  Note that
1655          the file must be readable by the user <literal>systemd-network</literal>, so it should be, e.g.,
1656          owned by <literal>root:systemd-network</literal> with a <literal>0640</literal> file mode. If the
1657          path refers to an <constant>AF_UNIX</constant> stream socket in the file system a connection is
1658          made to it and the key read from it.</para>
1659        </listitem>
1660      </varlistentry>
1661      <varlistentry>
1662        <term><varname>AllowedIPs=</varname></term>
1663        <listitem>
1664          <para>Sets a comma-separated list of IP (v4 or v6) addresses with CIDR masks
1665          from which this peer is allowed to send incoming traffic and to
1666          which outgoing traffic for this peer is directed.</para>
1667
1668          <para>The catch-all 0.0.0.0/0 may be specified for matching all IPv4 addresses,
1669          and ::/0 may be specified for matching all IPv6 addresses.</para>
1670
1671          <para>Note that this only affects <emphasis>routing inside the network interface itself</emphasis>,
1672          i.e. the packets that pass through the tunnel itself. To cause packets to be sent via the tunnel in
1673          the first place, an appropriate route needs to be added as well — either in the
1674          <literal>[Routes]</literal> section on the <literal>.network</literal> matching the wireguard
1675          interface, or externally to <filename>systemd-networkd</filename>.</para>
1676        </listitem>
1677      </varlistentry>
1678      <varlistentry>
1679        <term><varname>Endpoint=</varname></term>
1680        <listitem>
1681          <para>Sets an endpoint IP address or hostname, followed by a colon, and then
1682          a port number. This endpoint will be updated automatically once to
1683          the most recent source IP address and port of correctly
1684          authenticated packets from the peer at configuration time.</para>
1685        </listitem>
1686      </varlistentry>
1687      <varlistentry>
1688        <term><varname>PersistentKeepalive=</varname></term>
1689        <listitem>
1690          <para>Sets a seconds interval, between 1 and 65535 inclusive, of how often
1691          to send an authenticated empty packet to the peer for the purpose
1692          of keeping a stateful firewall or NAT mapping valid persistently.
1693          For example, if the interface very rarely sends traffic, but it
1694          might at anytime receive traffic from a peer, and it is behind NAT,
1695          the interface might benefit from having a persistent keepalive
1696          interval of 25 seconds. If set to 0 or "off", this option is
1697          disabled. By default or when unspecified, this option is off.
1698          Most users will not need this.</para>
1699        </listitem>
1700      </varlistentry>
1701      <varlistentry>
1702        <term><varname>RouteTable=</varname></term>
1703        <listitem>
1704          <para>The table identifier for the routes to the addresses specified in the
1705          <varname>AllowedIPs=</varname>. Takes a negative boolean value, one of the predefined names
1706          <literal>default</literal>, <literal>main</literal>, and <literal>local</literal>, names
1707          defined in <varname>RouteTable=</varname> in
1708          <citerefentry><refentrytitle>networkd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1709          or a number in the range 1…4294967295. Defaults to unset, and the value specified in the
1710          same setting in the [WireGuard] section will be used.</para>
1711        </listitem>
1712      </varlistentry>
1713      <varlistentry>
1714        <term><varname>RouteMetric=</varname></term>
1715        <listitem>
1716          <para>The priority of the routes to the addresses specified in the
1717          <varname>AllowedIPs=</varname>. Takes an integer in the range 0…4294967295. Defaults to
1718          unset, and the value specified in the same setting in the [WireGuard] section will be used.
1719          </para>
1720        </listitem>
1721      </varlistentry>
1722    </variablelist>
1723  </refsect1>
1724
1725  <refsect1>
1726    <title>[Bond] Section Options</title>
1727
1728    <para>The [Bond] section accepts the following
1729    key:</para>
1730
1731    <variablelist class='network-directives'>
1732      <varlistentry>
1733        <term><varname>Mode=</varname></term>
1734        <listitem>
1735          <para>Specifies one of the bonding policies. The default is
1736          <literal>balance-rr</literal> (round robin). Possible values are
1737          <literal>balance-rr</literal>,
1738          <literal>active-backup</literal>,
1739          <literal>balance-xor</literal>,
1740          <literal>broadcast</literal>,
1741          <literal>802.3ad</literal>,
1742          <literal>balance-tlb</literal>, and
1743          <literal>balance-alb</literal>.
1744          </para>
1745        </listitem>
1746      </varlistentry>
1747
1748      <varlistentry>
1749        <term><varname>TransmitHashPolicy=</varname></term>
1750        <listitem>
1751          <para>Selects the transmit hash policy to use for slave
1752          selection in balance-xor, 802.3ad, and tlb modes. Possible
1753          values are
1754          <literal>layer2</literal>,
1755          <literal>layer3+4</literal>,
1756          <literal>layer2+3</literal>,
1757          <literal>encap2+3</literal>, and
1758          <literal>encap3+4</literal>.
1759          </para>
1760        </listitem>
1761      </varlistentry>
1762
1763      <varlistentry>
1764        <term><varname>LACPTransmitRate=</varname></term>
1765        <listitem>
1766          <para>Specifies the rate with which link partner transmits
1767          Link Aggregation Control Protocol Data Unit packets in
1768          802.3ad mode. Possible values are <literal>slow</literal>,
1769          which requests partner to transmit LACPDUs every 30 seconds,
1770          and <literal>fast</literal>, which requests partner to
1771          transmit LACPDUs every second. The default value is
1772          <literal>slow</literal>.</para>
1773        </listitem>
1774      </varlistentry>
1775
1776      <varlistentry>
1777        <term><varname>MIIMonitorSec=</varname></term>
1778        <listitem>
1779          <para>Specifies the frequency that Media Independent
1780          Interface link monitoring will occur. A value of zero
1781          disables MII link monitoring. This value is rounded down to
1782          the nearest millisecond. The default value is 0.</para>
1783        </listitem>
1784      </varlistentry>
1785
1786      <varlistentry>
1787        <term><varname>UpDelaySec=</varname></term>
1788        <listitem>
1789          <para>Specifies the delay before a link is enabled after a
1790          link up status has been detected. This value is rounded down
1791          to a multiple of <varname>MIIMonitorSec=</varname>. The default value is
1792          0.</para>
1793        </listitem>
1794      </varlistentry>
1795
1796      <varlistentry>
1797        <term><varname>DownDelaySec=</varname></term>
1798        <listitem>
1799          <para>Specifies the delay before a link is disabled after a
1800          link down status has been detected. This value is rounded
1801          down to a multiple of <varname>MIIMonitorSec=</varname>. The default value is
1802          0.</para>
1803        </listitem>
1804      </varlistentry>
1805
1806      <varlistentry>
1807        <term><varname>LearnPacketIntervalSec=</varname></term>
1808        <listitem>
1809          <para>Specifies the number of seconds between instances where the bonding
1810          driver sends learning packets to each slave peer switch.
1811          The valid range is 1…0x7fffffff; the default value is 1. This option
1812          has an effect only for the balance-tlb and balance-alb modes.</para>
1813        </listitem>
1814      </varlistentry>
1815
1816      <varlistentry>
1817        <term><varname>AdSelect=</varname></term>
1818        <listitem>
1819          <para>Specifies the 802.3ad aggregation selection logic to use. Possible values are
1820          <literal>stable</literal>,
1821          <literal>bandwidth</literal> and
1822          <literal>count</literal>.
1823          </para>
1824        </listitem>
1825      </varlistentry>
1826
1827      <varlistentry>
1828        <term><varname>AdActorSystemPriority=</varname></term>
1829        <listitem>
1830          <para>Specifies the 802.3ad actor system priority. Takes a number in the range 1…65535.</para>
1831        </listitem>
1832      </varlistentry>
1833
1834      <varlistentry>
1835        <term><varname>AdUserPortKey=</varname></term>
1836        <listitem>
1837          <para>Specifies the 802.3ad user defined portion of the port key. Takes a number in the range
1838          0…1023.</para>
1839        </listitem>
1840      </varlistentry>
1841
1842      <varlistentry>
1843        <term><varname>AdActorSystem=</varname></term>
1844        <listitem>
1845          <para>Specifies the 802.3ad system MAC address. This cannot be a null or multicast address.
1846          </para>
1847        </listitem>
1848      </varlistentry>
1849
1850      <varlistentry>
1851        <term><varname>FailOverMACPolicy=</varname></term>
1852        <listitem>
1853          <para>Specifies whether the active-backup mode should set all slaves to
1854          the same MAC address at the time of enslavement or, when enabled, to perform special handling of the
1855          bond's MAC address in accordance with the selected policy. The default policy is none.
1856          Possible values are
1857          <literal>none</literal>,
1858          <literal>active</literal> and
1859          <literal>follow</literal>.
1860          </para>
1861        </listitem>
1862      </varlistentry>
1863
1864      <varlistentry>
1865        <term><varname>ARPValidate=</varname></term>
1866        <listitem>
1867          <para>Specifies whether or not ARP probes and replies should be
1868          validated in any mode that supports ARP monitoring, or whether
1869          non-ARP traffic should be filtered (disregarded) for link
1870          monitoring purposes. Possible values are
1871          <literal>none</literal>,
1872          <literal>active</literal>,
1873          <literal>backup</literal> and
1874          <literal>all</literal>.
1875          </para>
1876        </listitem>
1877      </varlistentry>
1878
1879      <varlistentry>
1880        <term><varname>ARPIntervalSec=</varname></term>
1881        <listitem>
1882          <para>Specifies the ARP link monitoring frequency. A value of 0 disables ARP monitoring. The
1883          default value is 0, and the default unit seconds.
1884          </para>
1885        </listitem>
1886      </varlistentry>
1887
1888      <varlistentry>
1889        <term><varname>ARPIPTargets=</varname></term>
1890        <listitem>
1891          <para>Specifies the IP addresses to use as ARP monitoring peers when
1892          <varname>ARPIntervalSec=</varname> is greater than 0. These are the targets of the ARP
1893          request sent to determine the health of the link to the targets.
1894          Specify these values in IPv4 dotted decimal format. At least one IP
1895          address must be given for ARP monitoring to function. The
1896          maximum number of targets that can be specified is 16. The
1897          default value is no IP addresses.
1898          </para>
1899        </listitem>
1900      </varlistentry>
1901
1902      <varlistentry>
1903        <term><varname>ARPAllTargets=</varname></term>
1904        <listitem>
1905          <para>Specifies the quantity of <varname>ARPIPTargets=</varname> that must be reachable
1906          in order for the ARP monitor to consider a slave as being up.
1907          This option affects only active-backup mode for slaves with
1908          ARPValidate enabled. Possible values are
1909          <literal>any</literal> and
1910          <literal>all</literal>.
1911          </para>
1912        </listitem>
1913      </varlistentry>
1914
1915      <varlistentry>
1916        <term><varname>PrimaryReselectPolicy=</varname></term>
1917        <listitem>
1918          <para>Specifies the reselection policy for the primary slave.  This
1919          affects how the primary slave is chosen to become the active slave
1920          when failure of the active slave or recovery of the primary slave
1921          occurs. This option is designed to prevent flip-flopping between
1922          the primary slave and other slaves.  Possible values are
1923          <literal>always</literal>,
1924          <literal>better</literal> and
1925          <literal>failure</literal>.
1926          </para>
1927        </listitem>
1928      </varlistentry>
1929
1930      <varlistentry>
1931        <term><varname>ResendIGMP=</varname></term>
1932        <listitem>
1933          <para>Specifies the number of IGMP membership reports to be issued after
1934          a failover event. One membership report is issued immediately after
1935          the failover, subsequent packets are sent in each 200ms interval.
1936          The valid range is 0…255. Defaults to 1. A value of 0
1937          prevents the IGMP membership report from being issued in response
1938          to the failover event.
1939          </para>
1940        </listitem>
1941      </varlistentry>
1942
1943      <varlistentry>
1944        <term><varname>PacketsPerSlave=</varname></term>
1945        <listitem>
1946          <para>Specify the number of packets to transmit through a slave before
1947          moving to the next one. When set to 0, then a slave is chosen at
1948          random. The valid range is 0…65535. Defaults to 1. This option
1949          only has effect when in balance-rr mode.
1950          </para>
1951        </listitem>
1952      </varlistentry>
1953
1954      <varlistentry>
1955        <term><varname>GratuitousARP=</varname></term>
1956        <listitem>
1957          <para>Specify the number of peer notifications (gratuitous ARPs and
1958          unsolicited IPv6 Neighbor Advertisements) to be issued after a
1959          failover event.  As soon as the link is up on the new slave,
1960          a peer notification is sent on the  bonding device and each
1961          VLAN sub-device.  This is repeated at each link monitor interval
1962          (ARPIntervalSec or MIIMonitorSec, whichever is active) if the number is
1963          greater than 1. The valid range is 0…255. The default value is 1.
1964          These options affect only the active-backup mode.
1965          </para>
1966        </listitem>
1967      </varlistentry>
1968
1969      <varlistentry>
1970        <term><varname>AllSlavesActive=</varname></term>
1971        <listitem>
1972          <para>Takes a boolean. Specifies that duplicate frames (received on inactive ports)
1973          should be dropped when false, or delivered when true. Normally, bonding will drop
1974          duplicate frames (received on inactive ports), which is desirable for
1975          most users. But there are some times it is nice to allow duplicate
1976          frames to be delivered. The default value is false (drop duplicate frames
1977          received on inactive ports).
1978          </para>
1979        </listitem>
1980      </varlistentry>
1981
1982      <varlistentry>
1983        <term><varname>DynamicTransmitLoadBalancing=</varname></term>
1984        <listitem>
1985          <para>Takes a boolean. Specifies if dynamic shuffling of flows is enabled. Applies only
1986          for balance-tlb mode. Defaults to unset.
1987          </para>
1988        </listitem>
1989      </varlistentry>
1990
1991      <varlistentry>
1992        <term><varname>MinLinks=</varname></term>
1993        <listitem>
1994          <para>Specifies the minimum number of links that must be active before
1995          asserting carrier. The default value is 0.
1996          </para>
1997        </listitem>
1998      </varlistentry>
1999    </variablelist>
2000
2001    <para>For more detail information see
2002    <ulink url="https://www.kernel.org/doc/Documentation/networking/bonding.txt">
2003    Linux Ethernet Bonding Driver HOWTO</ulink></para>
2004  </refsect1>
2005
2006  <refsect1>
2007    <title>[Xfrm] Section Options</title>
2008
2009    <para>The [Xfrm] section accepts the following
2010    keys:</para>
2011
2012    <variablelist class='network-directives'>
2013      <varlistentry>
2014        <term><varname>InterfaceId=</varname></term>
2015        <listitem>
2016          <para>Sets the ID/key of the xfrm interface which needs to be associated with a SA/policy.
2017          Can be decimal or hexadecimal, valid range is 1-0xffffffff. This is mandatory.</para>
2018        </listitem>
2019      </varlistentry>
2020      <varlistentry>
2021        <term><varname>Independent=</varname></term>
2022        <listitem>
2023          <para>Takes a boolean. If false (the default), the xfrm interface must have an underlying device
2024          which can be used for hardware offloading.</para>
2025        </listitem>
2026      </varlistentry>
2027    </variablelist>
2028
2029    <para>For more detail information see
2030      <ulink url="https://lwn.net/Articles/757391">Virtual XFRM Interfaces</ulink>.</para>
2031  </refsect1>
2032
2033  <refsect1>
2034    <title>[VRF] Section Options</title>
2035    <para>The [VRF] section only applies for
2036    netdevs of kind <literal>vrf</literal> and accepts the
2037    following key:</para>
2038
2039    <variablelist class='network-directives'>
2040      <varlistentry>
2041        <term><varname>Table=</varname></term>
2042        <listitem>
2043          <para>The numeric routing table identifier. This setting is compulsory.</para>
2044        </listitem>
2045      </varlistentry>
2046    </variablelist>
2047  </refsect1>
2048
2049  <refsect1>
2050    <title>[BatmanAdvanced] Section Options</title>
2051
2052    <para>The [BatmanAdvanced] section only applies for netdevs of kind <literal>batadv</literal> and accepts
2053    the following keys:</para>
2054
2055    <variablelist class='network-directives'>
2056      <varlistentry>
2057        <term><varname>GatewayMode=</varname></term>
2058        <listitem>
2059          <para>Takes one of <literal>off</literal>, <literal>server</literal>, or <literal>client</literal>.
2060          A batman-adv node can either run in server mode (sharing its internet
2061          connection with the mesh) or in client mode (searching for the most suitable internet connection
2062          in the mesh) or having the gateway support turned off entirely (which is the default setting).
2063          </para>
2064        </listitem>
2065      </varlistentry>
2066      <varlistentry>
2067        <term><varname>Aggregation=</varname></term>
2068        <listitem>
2069          <para>Takes a boolean value. Enables or disables aggregation of originator messages. Defaults to
2070           true.
2071          </para>
2072        </listitem>
2073      </varlistentry>
2074      <varlistentry>
2075        <term><varname>BridgeLoopAvoidance=</varname></term>
2076        <listitem>
2077          <para>Takes a boolean value. Enables or disables avoidance of loops on bridges. Defaults to true.
2078          </para>
2079        </listitem>
2080      </varlistentry>
2081      <varlistentry>
2082        <term><varname>DistributedArpTable=</varname></term>
2083        <listitem>
2084          <para>Takes a boolean value. Enables or disables the distributed ARP table. Defaults to true.</para>
2085        </listitem>
2086      </varlistentry>
2087      <varlistentry>
2088        <term><varname>Fragmentation=</varname></term>
2089        <listitem>
2090          <para>Takes a boolean value. Enables or disables fragmentation. Defaults to true.</para>
2091        </listitem>
2092      </varlistentry>
2093      <varlistentry>
2094        <term><varname>HopPenalty=</varname></term>
2095        <listitem>
2096          <para>The hop penalty setting allows one to modify
2097          <citerefentry project='mankier'><refentrytitle>batctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>
2098          preference for multihop routes vs. short routes. This integer value is applied to the
2099          TQ (Transmit Quality) of each forwarded OGM (Originator Message), thereby propagating the
2100          cost of an extra hop (the packet has to be received and retransmitted which costs airtime).
2101          A higher hop penalty will make it more unlikely that other nodes will choose this node as
2102          intermediate hop towards any given destination. The default hop penalty of '15' is a reasonable
2103          value for most setups and probably does not need to be changed. However, mobile nodes could
2104          choose a value of 255 (maximum value) to avoid being chosen as a router by other nodes.
2105          The minimum value is 0.
2106          </para>
2107        </listitem>
2108      </varlistentry>
2109      <varlistentry>
2110        <term><varname>OriginatorIntervalSec=</varname></term>
2111        <listitem>
2112          <para>The value specifies the interval in seconds, unless another time unit is specified in which
2113          batman-adv floods the network with its protocol information.
2114          See <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>
2115          for more information.</para>
2116        </listitem>
2117      </varlistentry>
2118      <varlistentry>
2119        <term><varname>GatewayBandwidthDown=</varname></term>
2120        <listitem>
2121          <para>If the node is a server, this
2122          parameter is used to inform other nodes in the network about
2123          this node's internet connection download bandwidth in bits per second. Just enter any number
2124          suffixed with K, M, G or T (base 1000) and the batman-adv
2125          module will propagate the entered value in the mesh.</para>
2126        </listitem>
2127      </varlistentry>
2128      <varlistentry>
2129        <term><varname>GatewayBandwidthUp=</varname></term>
2130        <listitem>
2131          <para>If the node is a server, this
2132          parameter is used to inform other nodes in the network about
2133          this node's internet connection upload bandwidth in bits per second. Just enter any number
2134          suffixed with K, M, G or T (base 1000) and the batman-adv
2135          module will propagate the entered value in the mesh.</para>
2136        </listitem>
2137      </varlistentry>
2138      <varlistentry>
2139        <term><varname>RoutingAlgorithm=</varname></term>
2140        <listitem>
2141          <para>This can be either <literal>batman-v</literal> or <literal>batman-iv</literal> and describes which routing_algo
2142          of <citerefentry project='mankier'><refentrytitle>batctl</refentrytitle><manvolnum>8</manvolnum></citerefentry> to use. The algorithm
2143          cannot be changed after interface creation. Defaults to <literal>batman-v</literal>.
2144          </para>
2145        </listitem>
2146      </varlistentry>
2147    </variablelist>
2148  </refsect1>
2149
2150  <refsect1>
2151    <title>[IPoIB] Section Options</title>
2152    <para>The [IPoIB] section only applies for netdevs of kind <literal>ipoib</literal> and accepts the
2153    following keys:</para>
2154
2155    <variablelist class='network-directives'>
2156      <varlistentry>
2157        <term><varname>PartitionKey=</varname></term>
2158        <listitem>
2159          <para>Takes an integer in the range 1…0xffff, except for 0x8000. Defaults to unset, and the
2160          kernel's default is used.</para>
2161        </listitem>
2162      </varlistentry>
2163
2164      <varlistentry id='ipoib_mode'>
2165        <term><varname>Mode=</varname></term>
2166        <listitem>
2167          <para>Takes one of the special values <literal>datagram</literal> or
2168          <literal>connected</literal>. Defaults to unset, and the kernel's default is used.</para>
2169
2170          <para>When <literal>datagram</literal>, the Infiniband unreliable datagram (UD) transport is
2171          used, and so the interface MTU is equal to the IB L2 MTU minus the IPoIB encapsulation
2172          header (4 bytes). For example, in a typical IB fabric with a 2K MTU, the IPoIB MTU will be
2173          2048 - 4 = 2044 bytes.</para>
2174
2175          <para>When <literal>connected</literal>, the Infiniband reliable connected (RC) transport is
2176          used. Connected mode takes advantage of the connected nature of the IB transport and allows
2177          an MTU up to the maximal IP packet size of 64K, which reduces the number of IP packets needed
2178          for handling large UDP datagrams, TCP segments, etc and increases the performance for large
2179          messages.</para>
2180        </listitem>
2181      </varlistentry>
2182
2183      <varlistentry id='ipoib_umcast'>
2184        <term><varname>IgnoreUserspaceMulticastGroup=</varname></term>
2185        <listitem>
2186          <para>Takes an boolean value. When true, the kernel ignores multicast groups handled by
2187          userspace. Defaults to unset, and the kernel's default is used.</para>
2188        </listitem>
2189      </varlistentry>
2190    </variablelist>
2191  </refsect1>
2192
2193  <refsect1>
2194    <title>[WLAN] Section Options</title>
2195    <para>The [WLAN] section only applies to WLAN interfaces, and accepts the following keys:</para>
2196
2197    <variablelist class='network-directives'>
2198      <varlistentry>
2199        <term><varname>PhysicalDevice=</varname></term>
2200        <listitem>
2201          <para>Specifies the name or index of the physical WLAN device (e.g. <literal>0</literal> or
2202          <literal>phy0</literal>). The list of the physical WLAN devices that exist os the host can be
2203          obtained by <command>iw phy</command> command. This option is mandatory.</para>
2204        </listitem>
2205      </varlistentry>
2206
2207      <varlistentry>
2208        <term><varname>Type=</varname></term>
2209        <listitem>
2210          <para>Specifies the type of the interface. Takes one of the <literal>ad-hoc</literal>,
2211          <literal>station</literal>, <literal>ap</literal>, <literal>ap-vlan</literal>,
2212          <literal>wds</literal>, <literal>monitor</literal>, <literal>mesh-point</literal>,
2213          <literal>p2p-client</literal>, <literal>p2p-go</literal>, <literal>p2p-device</literal>,
2214          <literal>ocb</literal>, and <literal>nan</literal>. This option is mandatory.</para>
2215        </listitem>
2216      </varlistentry>
2217
2218      <varlistentry>
2219        <term><varname>WDS=</varname></term>
2220        <listitem>
2221          <para>Enables the Wireless Distribution System (WDS) mode on the interface. The mode is also
2222          known as the <literal>4 address mode</literal>. Takes a boolean value. Defaults to unset, and
2223          the kernel's default will be used.</para>
2224        </listitem>
2225      </varlistentry>
2226    </variablelist>
2227  </refsect1>
2228
2229  <refsect1>
2230    <title>Examples</title>
2231    <example>
2232      <title>/etc/systemd/network/25-bridge.netdev</title>
2233
2234      <programlisting>[NetDev]
2235Name=bridge0
2236Kind=bridge</programlisting>
2237    </example>
2238
2239    <example>
2240      <title>/etc/systemd/network/25-vlan1.netdev</title>
2241
2242      <programlisting>[Match]
2243Virtualization=no
2244
2245[NetDev]
2246Name=vlan1
2247Kind=vlan
2248
2249[VLAN]
2250Id=1</programlisting>
2251    </example>
2252    <example>
2253      <title>/etc/systemd/network/25-ipip.netdev</title>
2254      <programlisting>[NetDev]
2255Name=ipip-tun
2256Kind=ipip
2257MTUBytes=1480
2258
2259[Tunnel]
2260Local=192.168.223.238
2261Remote=192.169.224.239
2262TTL=64</programlisting>
2263    </example>
2264    <example>
2265      <title>/etc/systemd/network/1-fou-tunnel.netdev</title>
2266      <programlisting>[NetDev]
2267Name=fou-tun
2268Kind=fou
2269
2270[FooOverUDP]
2271Port=5555
2272Protocol=4
2273      </programlisting>
2274    </example>
2275    <example>
2276      <title>/etc/systemd/network/25-fou-ipip.netdev</title>
2277      <programlisting>[NetDev]
2278Name=ipip-tun
2279Kind=ipip
2280
2281[Tunnel]
2282Independent=yes
2283Local=10.65.208.212
2284Remote=10.65.208.211
2285FooOverUDP=yes
2286FOUDestinationPort=5555
2287      </programlisting>
2288    </example>
2289    <example>
2290      <title>/etc/systemd/network/25-tap.netdev</title>
2291      <programlisting>[NetDev]
2292Name=tap-test
2293Kind=tap
2294
2295[Tap]
2296MultiQueue=yes
2297PacketInfo=yes</programlisting> </example>
2298
2299    <example>
2300      <title>/etc/systemd/network/25-sit.netdev</title>
2301      <programlisting>[NetDev]
2302Name=sit-tun
2303Kind=sit
2304MTUBytes=1480
2305
2306[Tunnel]
2307Local=10.65.223.238
2308Remote=10.65.223.239</programlisting>
2309    </example>
2310
2311    <example>
2312      <title>/etc/systemd/network/25-6rd.netdev</title>
2313      <programlisting>[NetDev]
2314Name=6rd-tun
2315Kind=sit
2316MTUBytes=1480
2317
2318[Tunnel]
2319Local=10.65.223.238
2320IPv6RapidDeploymentPrefix=2602::/24</programlisting>
2321    </example>
2322
2323    <example>
2324      <title>/etc/systemd/network/25-gre.netdev</title>
2325      <programlisting>[NetDev]
2326Name=gre-tun
2327Kind=gre
2328MTUBytes=1480
2329
2330[Tunnel]
2331Local=10.65.223.238
2332Remote=10.65.223.239</programlisting>
2333    </example>
2334
2335    <example>
2336      <title>/etc/systemd/network/25-ip6gre.netdev</title>
2337      <programlisting>[NetDev]
2338Name=ip6gre-tun
2339Kind=ip6gre
2340
2341[Tunnel]
2342Key=123</programlisting>
2343    </example>
2344
2345    <example>
2346      <title>/etc/systemd/network/25-vti.netdev</title>
2347
2348      <programlisting>[NetDev]
2349Name=vti-tun
2350Kind=vti
2351MTUBytes=1480
2352
2353[Tunnel]
2354Local=10.65.223.238
2355Remote=10.65.223.239</programlisting>
2356    </example>
2357
2358    <example>
2359      <title>/etc/systemd/network/25-veth.netdev</title>
2360      <programlisting>[NetDev]
2361Name=veth-test
2362Kind=veth
2363
2364[Peer]
2365Name=veth-peer</programlisting>
2366    </example>
2367
2368    <example>
2369      <title>/etc/systemd/network/25-bond.netdev</title>
2370      <programlisting>[NetDev]
2371Name=bond1
2372Kind=bond
2373
2374[Bond]
2375Mode=802.3ad
2376TransmitHashPolicy=layer3+4
2377MIIMonitorSec=1s
2378LACPTransmitRate=fast
2379</programlisting>
2380    </example>
2381
2382    <example>
2383      <title>/etc/systemd/network/25-dummy.netdev</title>
2384      <programlisting>[NetDev]
2385Name=dummy-test
2386Kind=dummy
2387MACAddress=12:34:56:78:9a:bc</programlisting>
2388    </example>
2389    <example>
2390      <title>/etc/systemd/network/25-vrf.netdev</title>
2391      <para>Create a VRF interface with table 42.</para>
2392      <programlisting>[NetDev]
2393Name=vrf-test
2394Kind=vrf
2395
2396[VRF]
2397Table=42</programlisting>
2398    </example>
2399
2400    <example>
2401      <title>/etc/systemd/network/25-macvtap.netdev</title>
2402      <para>Create a MacVTap device.</para>
2403      <programlisting>[NetDev]
2404Name=macvtap-test
2405Kind=macvtap
2406      </programlisting>
2407    </example>
2408    <example>
2409      <title>/etc/systemd/network/25-wireguard.netdev</title>
2410      <programlisting>[NetDev]
2411Name=wg0
2412Kind=wireguard
2413
2414[WireGuard]
2415PrivateKey=EEGlnEPYJV//kbvvIqxKkQwOiS+UENyPncC4bF46ong=
2416ListenPort=51820
2417
2418[WireGuardPeer]
2419PublicKey=RDf+LSpeEre7YEIKaxg+wbpsNV7du+ktR99uBEtIiCA=
2420AllowedIPs=fd31:bf08:57cb::/48,192.168.26.0/24
2421Endpoint=wireguard.example.com:51820</programlisting>
2422    </example>
2423
2424    <example>
2425      <title>/etc/systemd/network/27-xfrm.netdev</title>
2426      <programlisting>[NetDev]
2427Name=xfrm0
2428Kind=xfrm
2429
2430[Xfrm]
2431Independent=yes</programlisting>
2432    </example>
2433  </refsect1>
2434
2435  <refsect1>
2436    <title>See Also</title>
2437    <para>
2438      <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
2439      <citerefentry><refentrytitle>systemd-networkd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
2440      <citerefentry><refentrytitle>systemd.link</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
2441      <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
2442      <citerefentry><refentrytitle>systemd-network-generator.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
2443    </para>
2444  </refsect1>
2445
2446</refentry>
2447