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 -->
6 <refentry id=
"systemd.netdev" conditional='ENABLE_NETWORKD'
7 xmlns:
xi=
"http://www.w3.org/2001/XInclude">
10 <title>systemd.network
</title>
11 <productname>systemd
</productname>
15 <refentrytitle>systemd.netdev
</refentrytitle>
16 <manvolnum>5</manvolnum>
20 <refname>systemd.netdev
</refname>
21 <refpurpose>Virtual Network Device configuration
</refpurpose>
25 <para><filename><replaceable>netdev
</replaceable>.netdev
</filename></para>
29 <title>Description
</title>
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>
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
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
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>
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>
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>
76 <title>Supported netdev kinds
</title>
78 <para>The following kinds of virtual network devices may be
79 configured in
<filename>.netdev
</filename> files:
</para>
82 <title>Supported kinds of virtual network devices
</title>
85 <colspec colname='kind'
/>
86 <colspec colname='explanation'
/>
89 <entry>Description
</entry>
92 <row><entry><varname>bond
</varname></entry>
93 <entry>A bond device is an aggregation of all its slave devices. See
<ulink url=
"https://docs.kernel.org/networking/bonding.html">Linux Ethernet Bonding Driver HOWTO
</ulink> for details.
</entry></row>
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>
98 <row><entry><varname>dummy
</varname></entry>
99 <entry>A dummy device drops all packets sent to it.
</entry></row>
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>
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>
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>
110 <row><entry><varname>ip6gre
</varname></entry>
111 <entry>A Level
3 GRE tunnel over IPv6.
</entry></row>
113 <row><entry><varname>ip6tnl
</varname></entry>
114 <entry>An IPv4 or IPv6 tunnel over IPv6
</entry></row>
116 <row><entry><varname>ip6gretap
</varname></entry>
117 <entry>A Level
2 GRE tunnel over IPv6.
</entry></row>
119 <row><entry><varname>ipip
</varname></entry>
120 <entry>An IPv4 over IPv4 tunnel.
</entry></row>
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>
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>
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>
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>
134 <row><entry><varname>sit
</varname></entry>
135 <entry>An IPv6 over IPv4 tunnel.
</entry></row>
137 <row><entry><varname>tap
</varname></entry>
138 <entry>A persistent Level
2 tunnel between a network device and a device node.
</entry></row>
140 <row><entry><varname>tun
</varname></entry>
141 <entry>A persistent Level
3 tunnel between a network device and a device node.
</entry></row>
143 <row><entry><varname>veth
</varname></entry>
144 <entry>An Ethernet tunnel between a pair of network devices.
</entry></row>
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>
149 <row><entry><varname>vti
</varname></entry>
150 <entry>An IPv4 over IPSec tunnel.
</entry></row>
152 <row><entry><varname>vti6
</varname></entry>
153 <entry>An IPv6 over IPSec tunnel.
</entry></row>
155 <row><entry><varname>vxlan
</varname></entry>
156 <entry>A virtual extensible LAN (vxlan), for connecting Cloud computing deployments.
</entry></row>
158 <row><entry><varname>geneve
</varname></entry>
159 <entry>A GEneric NEtwork Virtualization Encapsulation (GENEVE) netdev driver.
</entry></row>
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>
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>
167 <row><entry><varname>vrf
</varname></entry>
168 <entry>A Virtual Routing and Forwarding (
<ulink url=
"https://docs.kernel.org/networking/vrf.html">VRF
</ulink>) interface to create separate routing and forwarding domains.
</entry></row>
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>
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.
177 <row><entry><varname>wireguard
</varname></entry>
178 <entry>WireGuard Secure Network Tunnel.
</entry></row>
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>
183 <row><entry><varname>fou
</varname></entry>
184 <entry>Foo-over-UDP tunneling.
</entry></row>
186 <row><entry><varname>xfrm
</varname></entry>
187 <entry>A virtual tunnel interface like vti/vti6 but with several advantages.
</entry></row>
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>
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>
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>
198 <row><entry><varname>ipoib
</varname></entry>
199 <entry>An IP over Infiniband subinterface.
</entry></row>
201 <row><entry><varname>wlan
</varname></entry>
202 <entry>A virtual wireless network (WLAN) interface.
</entry></row>
210 <title>[Match] Section Options
</title>
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>
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=
"credential" />
221 <xi:include href=
"systemd.link.xml" xpointer=
"architecture" />
222 <xi:include href=
"systemd.link.xml" xpointer=
"firmware" />
227 <title>[NetDev] Section Options
</title>
229 <para>The [NetDev] section accepts the
230 following keys:
</para>
232 <variablelist class='network-directives'
>
234 <term><varname>Description=
</varname></term>
236 <para>A free-form description of the netdev.
</para>
240 <term><varname>Name=
</varname></term>
242 <para>The interface name used when creating the netdev.
243 This setting is compulsory.
</para>
247 <term><varname>Kind=
</varname></term>
249 <para>The netdev kind. This setting is compulsory. See the
250 <literal>Supported netdev kinds
</literal> section for the
255 <term><varname>MTUBytes=
</varname></term>
257 <para>The maximum transmission unit in bytes to set for the device. The usual suffixes K, M, G
258 are supported and are understood to the base of
1024. For
<literal>tun
</literal> or
259 <literal>tap
</literal> devices,
<varname>MTUBytes=
</varname> setting is not currently supported in
260 [NetDev] section. Please specify it in [Link] section of
262 <citerefentry><refentrytitle>systemd.network
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
267 <term><varname>MACAddress=
</varname></term>
269 <para>Specifies the MAC address to use for the device, or takes the special value
270 <literal>none
</literal>. When
<literal>none
</literal>,
<command>systemd-networkd
</command>
271 does not request the MAC address for the device, and the kernel will assign a random MAC
272 address. For
<literal>tun
</literal>,
<literal>tap
</literal>, or
<literal>l2tp
</literal>
273 devices, the
<varname>MACAddress=
</varname> setting in the [NetDev] section is not
274 supported and will be ignored. Please specify it in the [Link] section of the corresponding
275 <citerefentry><refentrytitle>systemd.network
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
276 file. If this option is not set,
<literal>vlan
</literal> device inherits the MAC address of
277 the master interface. For other kind of netdevs, if this option is not set, then the MAC
278 address is generated based on the interface name and the
279 <citerefentry><refentrytitle>machine-id
</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
281 <para>Note, even if
<literal>none
</literal> is specified,
<command>systemd-udevd
</command>
282 will assign the persistent MAC address for the device, as
<filename>99-default.link
</filename>
283 has
<varname>MACAddressPolicy=persistent
</varname>. So, it is also necessary to create a
284 custom .link file for the device, if the MAC address assignment is not desired.
</para>
291 <title>[Bridge] Section Options
</title>
293 <para>The [Bridge] section only applies for
294 netdevs of kind
<literal>bridge
</literal>, and accepts the
295 following keys:
</para>
297 <variablelist class='network-directives'
>
299 <term><varname>HelloTimeSec=
</varname></term>
301 <para>HelloTimeSec specifies the number of seconds between two hello packets
302 sent out by the root bridge and the designated bridges. Hello packets are
303 used to communicate information about the topology throughout the entire
304 bridged local area network.
</para>
308 <term><varname>MaxAgeSec=
</varname></term>
310 <para>MaxAgeSec specifies the number of seconds of maximum message age.
311 If the last seen (received) hello packet is more than this number of
312 seconds old, the bridge in question will start the takeover procedure
313 in attempt to become the Root Bridge itself.
</para>
317 <term><varname>ForwardDelaySec=
</varname></term>
319 <para>ForwardDelaySec specifies the number of seconds spent in each
320 of the Listening and Learning states before the Forwarding state is entered.
</para>
324 <term><varname>AgeingTimeSec=
</varname></term>
326 <para>This specifies the number of seconds a MAC Address will be kept in
327 the forwarding database after having a packet received from this MAC Address.
</para>
331 <term><varname>Priority=
</varname></term>
333 <para>The priority of the bridge. An integer between
0 and
65535. A lower value
334 means higher priority. The bridge having the lowest priority will be elected as root bridge.
</para>
338 <term><varname>GroupForwardMask=
</varname></term>
340 <para>A
16-bit bitmask represented as an integer which allows forwarding of link
341 local frames with
802.1D reserved addresses (
01:
80:C2:
00:
00:
0X). A logical AND
342 is performed between the specified bitmask and the exponentiation of
2^X, the
343 lower nibble of the last octet of the MAC address. For example, a value of
8
344 would allow forwarding of frames addressed to
01:
80:C2:
00:
00:
03 (
802.1X PAE).
</para>
348 <term><varname>DefaultPVID=
</varname></term>
350 <para>This specifies the default port VLAN ID of a newly attached bridge port.
351 Set this to an integer in the range
1…
4094 or
<literal>none
</literal> to disable the PVID.
</para>
355 <term><varname>MulticastQuerier=
</varname></term>
357 <para>Takes a boolean. This setting controls the IFLA_BR_MCAST_QUERIER option in the kernel.
358 If enabled, the kernel will send general ICMP queries from a zero source address.
359 This feature should allow faster convergence on startup, but it causes some
360 multicast-aware switches to misbehave and disrupt forwarding of multicast packets.
361 When unset, the kernel's default will be used.
366 <term><varname>MulticastSnooping=
</varname></term>
368 <para>Takes a boolean. This setting controls the IFLA_BR_MCAST_SNOOPING option in the kernel.
369 If enabled, IGMP snooping monitors the Internet Group Management Protocol (IGMP) traffic
370 between hosts and multicast routers. When unset, the kernel's default will be used.
375 <term><varname>VLANFiltering=
</varname></term>
377 <para>Takes a boolean. This setting controls the IFLA_BR_VLAN_FILTERING option in the kernel.
378 If enabled, the bridge will be started in VLAN-filtering mode. When unset, the kernel's default will be used.
383 <term><varname>VLANProtocol=
</varname></term>
385 <para>Allows setting the protocol used for VLAN filtering. Takes
386 <option>802.1q
</option> or,
387 <option>802.1ad
</option>, and defaults to unset and kernel's default is used.
392 <term><varname>STP=
</varname></term>
394 <para>Takes a boolean. This enables the bridge's Spanning Tree Protocol (STP).
395 When unset, the kernel's default will be used.
400 <term><varname>MulticastIGMPVersion=
</varname></term>
402 <para>Allows changing bridge's multicast Internet Group Management Protocol (IGMP) version.
403 Takes an integer
2 or
3. When unset, the kernel's default will be used.
411 <title>[VLAN] Section Options
</title>
413 <para>The [VLAN] section only applies for
414 netdevs of kind
<literal>vlan
</literal>, and accepts the
415 following key:
</para>
417 <variablelist class='network-directives'
>
419 <term><varname>Id=
</varname></term>
421 <para>The VLAN ID to use. An integer in the range
0…
4094.
422 This setting is compulsory.
</para>
426 <term><varname>Protocol=
</varname></term>
428 <para>Allows setting the protocol used for the VLAN interface. Takes
<literal>802.1q
</literal> or,
429 <literal>802.1ad
</literal>, and defaults to unset and kernel's default is used.
</para>
433 <term><varname>GVRP=
</varname></term>
435 <para>Takes a boolean. The Generic VLAN Registration Protocol (GVRP) is a protocol that
436 allows automatic learning of VLANs on a network.
437 When unset, the kernel's default will be used.
442 <term><varname>MVRP=
</varname></term>
444 <para>Takes a boolean. Multiple VLAN Registration Protocol (MVRP) formerly known as GARP VLAN
445 Registration Protocol (GVRP) is a standards-based Layer
2 network protocol,
446 for automatic configuration of VLAN information on switches. It was defined
447 in the
802.1ak amendment to
802.1Q-
2005. When unset, the kernel's default will be used.
452 <term><varname>LooseBinding=
</varname></term>
454 <para>Takes a boolean. The VLAN loose binding mode, in which only the operational state is passed
455 from the parent to the associated VLANs, but the VLAN device state is not changed.
456 When unset, the kernel's default will be used.
</para>
460 <term><varname>ReorderHeader=
</varname></term>
462 <para>Takes a boolean. When enabled, the VLAN reorder header is used and VLAN interfaces behave
463 like physical interfaces. When unset, the kernel's default will be used.
</para>
467 <term><varname>EgressQOSMaps=
</varname></term>
468 <term><varname>IngressQOSMaps=
</varname></term>
470 <para>Defines a mapping of Linux internal packet priority (
<constant>SO_PRIORITY
</constant>)
471 to VLAN header PCP field for outgoing and incoming frames, respectively. Takes a
472 whitespace-separated list of integer pairs, where each integer must be in the range
473 1…
4294967294, in the format
<literal>from
</literal>-
<literal>to
</literal>, e.g.,
474 <literal>21-
7 45-
5</literal>. Note that
<literal>from
</literal> must be greater than or equal
475 to
<literal>to
</literal>. When unset, the kernel's default will be used.
</para>
482 <title>[MACVLAN] Section Options
</title>
484 <para>The [MACVLAN] section only applies for
485 netdevs of kind
<literal>macvlan
</literal>, and accepts the
486 following key:
</para>
488 <variablelist class='network-directives'
>
490 <term><varname>Mode=
</varname></term>
492 <para>The MACVLAN mode to use. The supported options are
493 <literal>private
</literal>,
494 <literal>vepa
</literal>,
495 <literal>bridge
</literal>,
496 <literal>passthru
</literal>, and
497 <literal>source
</literal>.
502 <term><varname>SourceMACAddress=
</varname></term>
504 <para>A whitespace-separated list of remote hardware addresses allowed on the MACVLAN. This
505 option only has an effect in source mode. Use full colon-, hyphen- or dot-delimited
506 hexadecimal. This option may appear more than once, in which case the lists are merged. If
507 the empty string is assigned to this option, the list of hardware addresses defined prior
508 to this is reset. Defaults to unset.
</para>
512 <term><varname>BroadcastMulticastQueueLength=
</varname></term>
514 <para>Specifies the length of the receive queue for broadcast/multicast packets. An unsigned
515 integer in the range
0…
4294967294. Defaults to unset.
</para>
522 <title>[MACVTAP] Section Options
</title>
524 <para>The [MACVTAP] section applies for netdevs of kind
<literal>macvtap
</literal> and accepts the same
525 keys as [MACVLAN].
</para>
529 <title>[IPVLAN] Section Options
</title>
531 <para>The [IPVLAN] section only applies for
532 netdevs of kind
<literal>ipvlan
</literal>, and accepts the
533 following key:
</para>
535 <variablelist class='network-directives'
>
537 <term><varname>Mode=
</varname></term>
539 <para>The IPVLAN mode to use. The supported options are
540 <literal>L2
</literal>,
<literal>L3
</literal> and
<literal>L3S
</literal>.
545 <term><varname>Flags=
</varname></term>
547 <para>The IPVLAN flags to use. The supported options are
548 <literal>bridge
</literal>,
<literal>private
</literal> and
<literal>vepa
</literal>.
556 <title>[IPVTAP] Section Options
</title>
558 <para>The [IPVTAP] section only applies for netdevs of kind
<literal>ipvtap
</literal> and accepts the
559 same keys as [IPVLAN].
</para>
563 <title>[VXLAN] Section Options
</title>
565 <para>The [VXLAN] section only applies for
566 netdevs of kind
<literal>vxlan
</literal>, and accepts the
567 following keys:
</para>
569 <variablelist class='network-directives'
>
571 <term><varname>VNI=
</varname></term>
573 <para>The VXLAN Network Identifier (or VXLAN Segment ID). Takes a number in the range
1…
16777215.
</para>
577 <term><varname>Remote=
</varname></term>
579 <para>Configures destination IP address.
</para>
583 <term><varname>Local=
</varname></term>
585 <para>Configures local IP address. It must be an address on the underlying interface of the
586 VXLAN interface, or one of the special values
<literal>ipv4_link_local
</literal>,
587 <literal>ipv6_link_local
</literal>,
<literal>dhcp4
</literal>,
<literal>dhcp6
</literal>, and
588 <literal>slaac
</literal>. If one of the special values is specified, an address which matches
589 the corresponding type on the underlying interface will be used. Defaults to unset.
</para>
593 <term><varname>Group=
</varname></term>
595 <para>Configures VXLAN multicast group IP address. All members of a VXLAN must use the same
596 multicast group address.
</para>
600 <term><varname>TOS=
</varname></term>
602 <para>The Type Of Service byte value for a vxlan interface.
</para>
606 <term><varname>TTL=
</varname></term>
608 <para>A fixed Time To Live N on Virtual eXtensible Local Area Network packets.
609 Takes
<literal>inherit
</literal> or a number in the range
0…
255.
0 is a special
610 value meaning inherit the inner protocol's TTL value.
<literal>inherit
</literal>
611 means that it will inherit the outer protocol's TTL value.
</para>
615 <term><varname>MacLearning=
</varname></term>
617 <para>Takes a boolean. When true, enables dynamic MAC learning
618 to discover remote MAC addresses.
</para>
622 <term><varname>FDBAgeingSec=
</varname></term>
624 <para>The lifetime of Forwarding Database entry learnt by
625 the kernel, in seconds.
</para>
629 <term><varname>MaximumFDBEntries=
</varname></term>
631 <para>Configures maximum number of FDB entries.
</para>
635 <term><varname>ReduceARPProxy=
</varname></term>
637 <para>Takes a boolean. When true, bridge-connected VXLAN tunnel
638 endpoint answers ARP requests from the local bridge on behalf
639 of remote Distributed Overlay Virtual Ethernet
640 <ulink url=
"https://en.wikipedia.org/wiki/Distributed_Overlay_Virtual_Ethernet">
641 (DOVE)
</ulink> clients. Defaults to false.
</para>
645 <term><varname>L2MissNotification=
</varname></term>
647 <para>Takes a boolean. When true, enables netlink LLADDR miss
648 notifications.
</para>
652 <term><varname>L3MissNotification=
</varname></term>
654 <para>Takes a boolean. When true, enables netlink IP address miss notifications.
</para>
658 <term><varname>RouteShortCircuit=
</varname></term>
660 <para>Takes a boolean. When true, route short circuiting is turned
665 <term><varname>UDPChecksum=
</varname></term>
667 <para>Takes a boolean. When true, transmitting UDP checksums when doing VXLAN/IPv4 is turned on.
</para>
671 <term><varname>UDP6ZeroChecksumTx=
</varname></term>
673 <para>Takes a boolean. When true, sending zero checksums in VXLAN/IPv6 is turned on.
</para>
677 <term><varname>UDP6ZeroChecksumRx=
</varname></term>
679 <para>Takes a boolean. When true, receiving zero checksums in VXLAN/IPv6 is turned on.
</para>
683 <term><varname>RemoteChecksumTx=
</varname></term>
685 <para>Takes a boolean. When true, remote transmit checksum offload of VXLAN is turned on.
</para>
689 <term><varname>RemoteChecksumRx=
</varname></term>
691 <para>Takes a boolean. When true, remote receive checksum offload in VXLAN is turned on.
</para>
695 <term><varname>GroupPolicyExtension=
</varname></term>
697 <para>Takes a boolean. When true, it enables Group Policy VXLAN extension security label mechanism
698 across network peers based on VXLAN. For details about the Group Policy VXLAN, see the
699 <ulink url=
"https://tools.ietf.org/html/draft-smith-vxlan-group-policy">
700 VXLAN Group Policy
</ulink> document. Defaults to false.
</para>
704 <term><varname>GenericProtocolExtension=
</varname></term>
706 <para>Takes a boolean. When true, Generic Protocol Extension extends the existing VXLAN protocol
707 to provide protocol typing, OAM, and versioning capabilities. For details about the VXLAN GPE
708 Header, see the
<ulink url=
"https://tools.ietf.org/html/draft-ietf-nvo3-vxlan-gpe-07">
709 Generic Protocol Extension for VXLAN
</ulink> document. If destination port is not specified and
710 Generic Protocol Extension is set then default port of
4790 is used. Defaults to false.
</para>
714 <term><varname>DestinationPort=
</varname></term>
716 <para>Configures the default destination UDP port. If the destination port is not specified then
717 Linux kernel default will be used. Set to
4789 to get the IANA assigned value.
</para>
721 <term><varname>PortRange=
</varname></term>
723 <para>Configures the source port range for the VXLAN. The kernel assigns the source UDP port based
724 on the flow to help the receiver to do load balancing. When this option is not set, the normal
725 range of local UDP ports is used.
</para>
729 <term><varname>FlowLabel=
</varname></term>
731 <para>Specifies the flow label to use in outgoing packets.
732 The valid range is
0-
1048575.
737 <term><varname>IPDoNotFragment=
</varname></term>
739 <para>Allows setting the IPv4 Do not Fragment (DF) bit in outgoing packets, or to inherit its
740 value from the IPv4 inner header. Takes a boolean value, or
<literal>inherit
</literal>. Set
741 to
<literal>inherit
</literal> if the encapsulated protocol is IPv6. When unset, the kernel's
742 default will be used.
</para>
746 <term><varname>Independent=
</varname></term>
748 <para>Takes a boolean. When true, the vxlan interface is created without any underlying network
749 interface. Defaults to false, which means that a .network file that requests this VXLAN interface
750 using
<varname>VXLAN=
</varname> is required for the VXLAN to be created.
</para>
757 <title>[GENEVE] Section Options
</title>
759 <para>The [GENEVE] section only applies for
760 netdevs of kind
<literal>geneve
</literal>, and accepts the
761 following keys:
</para>
763 <variablelist class='network-directives'
>
765 <term><varname>Id=
</varname></term>
767 <para>Specifies the Virtual Network Identifier (VNI) to use, a number between
0 and
16777215. This
768 field is mandatory.
</para>
772 <term><varname>Remote=
</varname></term>
774 <para>Specifies the unicast destination IP address to use in outgoing packets.
</para>
778 <term><varname>TOS=
</varname></term>
780 <para>Specifies the TOS value to use in outgoing packets. Takes a number between
1 and
255.
</para>
784 <term><varname>TTL=
</varname></term>
786 <para>Accepts the same values as in the [VXLAN] section, except that when unset
787 or set to
0, the kernel's default will be used, meaning that packet TTL will be set from
788 <filename>/proc/sys/net/ipv4/ip_default_ttl
</filename>.
</para>
792 <term><varname>UDPChecksum=
</varname></term>
794 <para>Takes a boolean. When true, specifies that UDP checksum is calculated for transmitted packets
799 <term><varname>UDP6ZeroChecksumTx=
</varname></term>
801 <para>Takes a boolean. When true, skip UDP checksum calculation for transmitted packets over IPv6.
</para>
805 <term><varname>UDP6ZeroChecksumRx=
</varname></term>
807 <para>Takes a boolean. When true, allows incoming UDP packets over IPv6 with zero checksum field.
</para>
811 <term><varname>DestinationPort=
</varname></term>
813 <para>Specifies destination port. Defaults to
6081. If not set or assigned the empty string, the default
814 port of
6081 is used.
</para>
818 <term><varname>FlowLabel=
</varname></term>
820 <para>Specifies the flow label to use in outgoing packets.
</para>
824 <term><varname>IPDoNotFragment=
</varname></term>
826 <para>Accepts the same key as in [VXLAN] section.
</para>
830 <term><varname>InheritInnerProtocol=
</varname></term>
832 <para>Takes a boolean. When true, inner Layer
3 protocol is set as Protocol Type in the GENEVE
833 header instead of Ethernet. Defaults to false.
</para>
840 <title>[BareUDP] Section Options
</title>
842 <para>The [BareUDP] section only applies for
843 netdevs of kind
<literal>bareudp
</literal>, and accepts the
844 following keys:
</para>
846 <variablelist class='network-directives'
>
848 <term><varname>DestinationPort=
</varname></term>
850 <para>Specifies the destination UDP port (in range
1…
65535). This is mandatory.
</para>
855 <term><varname>EtherType=
</varname></term>
857 <para>Specifies the L3 protocol. Takes one of
<literal>ipv4
</literal>,
<literal>ipv6
</literal>,
<literal>mpls-uc
</literal>
858 or
<literal>mpls-mc
</literal>. This is mandatory.
</para>
865 <title>[L2TP] Section Options
</title>
867 <para>The [L2TP] section only applies for
868 netdevs of kind
<literal>l2tp
</literal>, and accepts the
869 following keys:
</para>
871 <variablelist class='network-directives'
>
873 <term><varname>TunnelId=
</varname></term>
875 <para>Specifies the tunnel identifier. Takes an number in the range
1…
4294967295. The value used
876 must match the
<literal>PeerTunnelId=
</literal> value being used at the peer. This setting is
881 <term><varname>PeerTunnelId=
</varname></term>
883 <para>Specifies the peer tunnel id. Takes a number in the range
1…
4294967295. The value used must
884 match the
<literal>TunnelId=
</literal> value being used at the peer. This setting is compulsory.
889 <term><varname>Remote=
</varname></term>
891 <para>Specifies the IP address of the remote peer. This setting is compulsory.
</para>
895 <term><varname>Local=
</varname></term>
897 <para>Specifies the IP address of a local interface. Takes an IP address, or the special
898 values
<literal>auto
</literal>,
<literal>static
</literal>, or
<literal>dynamic
</literal>.
899 Optionally a name of a local interface can be specified after
<literal>@
</literal>, e.g.
900 <literal>192.168.0.1@eth0
</literal> or
<literal>auto@eth0
</literal>. When an address is
901 specified, then a local or specified interface must have the address, and the remote address
902 must be accessible through the local address. If
<literal>auto
</literal>, then one of the
903 addresses on a local or specified interface which is accessible to the remote address will be
904 used. Similarly, if
<literal>static
</literal> or
<literal>dynamic
</literal> is set, then one
905 of the static or dynamic addresses will be used. Defaults to
<literal>auto
</literal>.
</para>
909 <term><varname>EncapsulationType=
</varname></term>
911 <para>Specifies the encapsulation type of the tunnel. Takes one of
<literal>udp
</literal> or
912 <literal>ip
</literal>.
</para>
916 <term><varname>UDPSourcePort=
</varname></term>
918 <para>Specifies the UDP source port to be used for the tunnel. When UDP encapsulation is selected
919 it's mandatory. Ignored when IP encapsulation is selected.
</para>
923 <term><varname>UDPDestinationPort=
</varname></term>
925 <para>Specifies destination port. When UDP encapsulation is selected it's mandatory. Ignored when IP
926 encapsulation is selected.
</para>
930 <term><varname>UDPChecksum=
</varname></term>
932 <para>Takes a boolean. When true, specifies that UDP checksum is calculated for transmitted packets
937 <term><varname>UDP6ZeroChecksumTx=
</varname></term>
939 <para>Takes a boolean. When true, skip UDP checksum calculation for transmitted packets over IPv6.
</para>
943 <term><varname>UDP6ZeroChecksumRx=
</varname></term>
945 <para>Takes a boolean. When true, allows incoming UDP packets over IPv6 with zero checksum field.
</para>
952 <title>[L2TPSession] Section Options
</title>
954 <para>The [L2TPSession] section only applies for
955 netdevs of kind
<literal>l2tp
</literal>, and accepts the
956 following keys:
</para>
957 <variablelist class='network-directives'
>
959 <term><varname>Name=
</varname></term>
961 <para>Specifies the name of the session. This setting is compulsory.
</para>
965 <term><varname>SessionId=
</varname></term>
967 <para>Specifies the session identifier. Takes an number in the range
1…
4294967295. The value used
968 must match the
<literal>SessionId=
</literal> value being used at the peer. This setting is
973 <term><varname>PeerSessionId=
</varname></term>
975 <para>Specifies the peer session identifier. Takes an number in the range
1…
4294967295.
976 The value used must match the
<literal>PeerSessionId=
</literal> value being used at the peer.
977 This setting is compulsory.
</para>
981 <term><varname>Layer2SpecificHeader=
</varname></term>
983 <para>Specifies layer2specific header type of the session. One of
<literal>none
</literal> or
<literal>default
</literal>. Defaults to
<literal>default
</literal>.
</para>
990 <title>[MACsec] Section Options
</title>
992 <para>The [MACsec] section only applies for network devices of kind
993 <literal>macsec
</literal>, and accepts the following keys:
</para>
995 <variablelist class='network-directives'
>
997 <term><varname>Port=
</varname></term>
999 <para>Specifies the port to be used for the MACsec transmit channel. The port is used to make
1000 secure channel identifier (SCI). Takes a value between
1 and
65535. Defaults to unset.
1005 <term><varname>Encrypt=
</varname></term>
1007 <para>Takes a boolean. When true, enable encryption. Defaults to unset.
</para>
1014 <title>[MACsecReceiveChannel] Section Options
</title>
1015 <para>The [MACsecReceiveChannel] section only applies for network devices of
1016 kind
<literal>macsec
</literal>, and accepts the following keys:
</para>
1018 <variablelist class='network-directives'
>
1020 <term><varname>Port=
</varname></term>
1022 <para>Specifies the port to be used for the MACsec receive channel. The port is used to make
1023 secure channel identifier (SCI). Takes a value between
1 and
65535. This option is
1024 compulsory, and is not set by default.
</para>
1028 <term><varname>MACAddress=
</varname></term>
1030 <para>Specifies the MAC address to be used for the MACsec receive channel. The MAC address
1031 used to make secure channel identifier (SCI). This setting is compulsory, and is not set by
1039 <title>[MACsecTransmitAssociation] Section Options
</title>
1041 <para>The [MACsecTransmitAssociation] section only applies for network devices
1042 of kind
<literal>macsec
</literal>, and accepts the following keys:
</para>
1044 <variablelist class='network-directives'
>
1046 <term><varname>PacketNumber=
</varname></term>
1048 <para>Specifies the packet number to be used for replay protection and the construction of
1049 the initialization vector (along with the secure channel identifier [SCI]). Takes a value
1050 between
1-
4,
294,
967,
295. Defaults to unset.
1055 <term><varname>KeyId=
</varname></term>
1057 <para>Specifies the identification for the key. Takes a number between
0-
255. This option
1058 is compulsory, and is not set by default.
</para>
1062 <term><varname>Key=
</varname></term>
1064 <para>Specifies the encryption key used in the transmission channel. The same key must be
1065 configured on the peer’s matching receive channel. This setting is compulsory, and is not set
1066 by default. Takes a
128-bit key encoded in a hexadecimal string, for example
1067 <literal>dffafc8d7b9a43d5b9a3dfbbf6a30c16
</literal>.
</para>
1071 <term><varname>KeyFile=
</varname></term>
1073 <para>Takes an absolute path to a file which contains a
128-bit key encoded in a hexadecimal string,
1074 which will be used in the transmission channel. When this option is specified,
1075 <varname>Key=
</varname> is ignored. Note that the file must be readable by the user
1076 <literal>systemd-network
</literal>, so it should be, e.g., owned by
1077 <literal>root:systemd-network
</literal> with a
<literal>0640</literal> file mode. If the path
1078 refers to an
<constant>AF_UNIX
</constant> stream socket in the file system a connection is made to
1079 it and the key read from it.
</para>
1083 <term><varname>Activate=
</varname></term>
1085 <para>Takes a boolean. If enabled, then the security association is activated. Defaults to
1090 <term><varname>UseForEncoding=
</varname></term>
1092 <para>Takes a boolean. If enabled, then the security association is used for encoding. Only
1093 one [MACsecTransmitAssociation] section can enable this option. When enabled,
1094 <varname>Activate=yes
</varname> is implied. Defaults to unset.
</para>
1101 <title>[MACsecReceiveAssociation] Section Options
</title>
1103 <para>The [MACsecReceiveAssociation] section only applies for
1104 network devices of kind
<literal>macsec
</literal>, and accepts the
1105 following keys:
</para>
1107 <variablelist class='network-directives'
>
1109 <term><varname>Port=
</varname></term>
1111 <para>Accepts the same key as in [MACsecReceiveChannel] section.
</para>
1115 <term><varname>MACAddress=
</varname></term>
1117 <para>Accepts the same key as in [MACsecReceiveChannel] section.
</para>
1121 <term><varname>PacketNumber=
</varname></term>
1123 <para>Accepts the same key as in [MACsecTransmitAssociation] section.
</para>
1127 <term><varname>KeyId=
</varname></term>
1129 <para>Accepts the same key as in [MACsecTransmitAssociation] section.
</para>
1133 <term><varname>Key=
</varname></term>
1135 <para>Accepts the same key as in [MACsecTransmitAssociation] section.
</para>
1139 <term><varname>KeyFile=
</varname></term>
1141 <para>Accepts the same key as in [MACsecTransmitAssociation] section.
</para>
1145 <term><varname>Activate=
</varname></term>
1147 <para>Accepts the same key as in [MACsecTransmitAssociation] section.
</para>
1154 <title>[Tunnel] Section Options
</title>
1156 <para>The [Tunnel] section only applies for
1158 <literal>ipip
</literal>,
1159 <literal>sit
</literal>,
1160 <literal>gre
</literal>,
1161 <literal>gretap
</literal>,
1162 <literal>ip6gre
</literal>,
1163 <literal>ip6gretap
</literal>,
1164 <literal>vti
</literal>,
1165 <literal>vti6
</literal>,
1166 <literal>ip6tnl
</literal>, and
1167 <literal>erspan
</literal> and accepts
1168 the following keys:
</para>
1170 <variablelist class='network-directives'
>
1172 <term><varname>External=
</varname></term>
1174 <para>Takes a boolean value. When true, then the tunnel is externally controlled, which is
1175 also known as collect metadata mode, and most settings below like
<varname>Local=
</varname>
1176 or
<varname>Remote=
</varname> are ignored. This implies
<varname>Independent=
</varname>.
1177 Defaults to false.
</para>
1181 <term><varname>Local=
</varname></term>
1183 <para>A static local address for tunneled packets. It must be an address on another interface
1184 of this host, or one of the special values
<literal>any
</literal>,
1185 <literal>ipv4_link_local
</literal>,
<literal>ipv6_link_local
</literal>,
1186 <literal>dhcp4
</literal>,
<literal>dhcp6
</literal>, and
<literal>slaac
</literal>. If one
1187 of the special values except for
<literal>any
</literal> is specified, an address which
1188 matches the corresponding type on the underlying interface will be used. Defaults to
1189 <literal>any
</literal>.
</para>
1193 <term><varname>Remote=
</varname></term>
1195 <para>The remote endpoint of the tunnel. Takes an IP address or the special value
1196 <literal>any
</literal>.
</para>
1200 <term><varname>TOS=
</varname></term>
1202 <para>The Type Of Service byte value for a tunnel interface.
1203 For details about the TOS, see the
1204 <ulink url=
"http://tools.ietf.org/html/rfc1349"> Type of
1205 Service in the Internet Protocol Suite
</ulink> document.
1210 <term><varname>TTL=
</varname></term>
1212 <para>A fixed Time To Live N on tunneled packets. N is a
1213 number in the range
1…
255.
0 is a special value meaning that
1214 packets inherit the TTL value. The default value for IPv4
1215 tunnels is
0 (inherit). The default value for IPv6 tunnels is
1220 <term><varname>DiscoverPathMTU=
</varname></term>
1222 <para>Takes a boolean. When true, enables Path MTU Discovery on
1227 <term><varname>IPv6FlowLabel=
</varname></term>
1229 <para>Configures the
20-bit flow label (see
<ulink url=
"https://tools.ietf.org/html/rfc6437">
1230 RFC
6437</ulink>) field in the IPv6 header (see
<ulink url=
"https://tools.ietf.org/html/rfc2460">
1231 RFC
2460</ulink>), which is used by a node to label packets of a flow.
1232 It is only used for IPv6 tunnels.
1233 A flow label of zero is used to indicate packets that have
1235 It can be configured to a value in the range
0…
0xFFFFF, or be
1236 set to
<literal>inherit
</literal>, in which case the original flowlabel is used.
</para>
1240 <term><varname>CopyDSCP=
</varname></term>
1242 <para>Takes a boolean. When true, the Differentiated Service Code
1243 Point (DSCP) field will be copied to the inner header from
1244 outer header during the decapsulation of an IPv6 tunnel
1245 packet. DSCP is a field in an IP packet that enables different
1246 levels of service to be assigned to network traffic.
1247 Defaults to
<literal>no
</literal>.
1252 <term><varname>EncapsulationLimit=
</varname></term>
1254 <para>The Tunnel Encapsulation Limit option specifies how many additional
1255 levels of encapsulation are permitted to be prepended to the packet.
1256 For example, a Tunnel Encapsulation Limit option containing a limit
1257 value of zero means that a packet carrying that option may not enter
1258 another tunnel before exiting the current tunnel.
1259 (see
<ulink url=
"https://tools.ietf.org/html/rfc2473#section-4.1.1"> RFC
2473</ulink>).
1260 The valid range is
0…
255 and
<literal>none
</literal>. Defaults to
4.
1265 <term><varname>Key=
</varname></term>
1267 <para>The
<varname>Key=
</varname> parameter specifies the same key to use in
1268 both directions (
<varname>InputKey=
</varname> and
<varname>OutputKey=
</varname>).
1269 The
<varname>Key=
</varname> is either a number or an IPv4 address-like dotted quad.
1270 It is used as mark-configured SAD/SPD entry as part of the lookup key (both in data
1271 and control path) in IP XFRM (framework used to implement IPsec protocol).
1272 See
<ulink url=
"https://man7.org/linux/man-pages/man8/ip-xfrm.8.html">
1273 ip-xfrm — transform configuration
</ulink> for details. It is only used for VTI/VTI6,
1274 GRE, GRETAP, and ERSPAN tunnels.
</para>
1278 <term><varname>InputKey=
</varname></term>
1280 <para>The
<varname>InputKey=
</varname> parameter specifies the key to use for input.
1281 The format is same as
<varname>Key=
</varname>. It is only used for VTI/VTI6, GRE, GRETAP,
1282 and ERSPAN tunnels.
</para>
1286 <term><varname>OutputKey=
</varname></term>
1288 <para>The
<varname>OutputKey=
</varname> parameter specifies the key to use for output.
1289 The format is same as
<varname>Key=
</varname>. It is only used for VTI/VTI6, GRE, GRETAP,
1290 and ERSPAN tunnels.
</para>
1294 <term><varname>Mode=
</varname></term>
1296 <para>An
<literal>ip6tnl
</literal> tunnel can be in one of three
1298 <literal>ip6ip6
</literal> for IPv6 over IPv6,
1299 <literal>ipip6
</literal> for IPv4 over IPv6 or
1300 <literal>any
</literal> for either.
1305 <term><varname>Independent=
</varname></term>
1307 <para>Takes a boolean. When false (the default), the tunnel is always created over some network
1308 device, and a .network file that requests this tunnel using
<varname>Tunnel=
</varname> is required
1309 for the tunnel to be created. When true, the tunnel is created independently of any network as
1310 "tunnel@NONE".
</para>
1314 <term><varname>AssignToLoopback=
</varname></term>
1316 <para>Takes a boolean. If set to
<literal>yes
</literal>, the loopback interface
<literal>lo
</literal>
1317 is used as the underlying device of the tunnel interface. Defaults to
<literal>no
</literal>.
</para>
1321 <term><varname>AllowLocalRemote=
</varname></term>
1323 <para>Takes a boolean. When true allows tunnel traffic on
<varname>ip6tnl
</varname> devices where the remote endpoint is a local host address.
1324 When unset, the kernel's default will be used.
1329 <term><varname>FooOverUDP=
</varname></term>
1331 <para>Takes a boolean. Specifies whether
<varname>FooOverUDP=
</varname> tunnel is to be configured.
1332 Defaults to false. This takes effects only for IPIP, SIT, GRE, and GRETAP tunnels.
1333 For more detail information see
1334 <ulink url=
"https://lwn.net/Articles/614348">Foo over UDP
</ulink></para>
1338 <term><varname>FOUDestinationPort=
</varname></term>
1340 <para>This setting specifies the UDP destination port for encapsulation.
1341 This field is mandatory when
<varname>FooOverUDP=yes
</varname>, and is not set by default.
</para>
1345 <term><varname>FOUSourcePort=
</varname></term>
1347 <para>This setting specifies the UDP source port for encapsulation. Defaults to
<constant>0</constant>
1348 — that is, the source port for packets is left to the network stack to decide.
</para>
1352 <term><varname>Encapsulation=
</varname></term>
1354 <para>Accepts the same key as in the [FooOverUDP] section.
</para>
1358 <term><varname>IPv6RapidDeploymentPrefix=
</varname></term>
1360 <para>Reconfigure the tunnel for
<ulink url=
"https://tools.ietf.org/html/rfc5569">IPv6 Rapid
1361 Deployment
</ulink>, also known as
6rd. The value is an ISP-specific IPv6 prefix with a non-zero length. Only
1362 applicable to SIT tunnels.
</para>
1366 <term><varname>ISATAP=
</varname></term>
1368 <para>Takes a boolean. If set, configures the tunnel as Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) tunnel.
1369 Only applicable to SIT tunnels. When unset, the kernel's default will be used.
</para>
1373 <term><varname>SerializeTunneledPackets=
</varname></term>
1375 <para>Takes a boolean. If set to yes, then packets are serialized. Only applies for GRE,
1376 GRETAP, and ERSPAN tunnels. When unset, the kernel's default will be used.
1381 <term><varname>ERSPANVersion=
</varname></term>
1383 <para>Specifies the ERSPAN version number. Takes
0 for version
0 (a.k.a. type I),
1 for version
1
1384 (a.k.a. type II), or
2 for version
2 (a.k.a. type III). Defaults to
1.
</para>
1388 <term><varname>ERSPANIndex=
</varname></term>
1390 <para>Specifies the ERSPAN v1 index field for the interface. Takes an integer in the range
1391 0…
1048575, which is associated with the ERSPAN traffic's source port and direction. Only used when
1392 <varname>ERSPANVersion=
1</varname>. Defaults to
0.
</para>
1396 <term><varname>ERSPANDirection=
</varname></term>
1398 <para>Specifies the ERSPAN v2 mirrored traffic's direction. Takes
<literal>ingress
</literal> or
1399 <literal>egress
</literal>. Only used when
<varname>ERSPANVersion=
2</varname>. Defaults to
1400 <literal>ingress
</literal>.
</para>
1404 <term><varname>ERSPANHardwareId=
</varname></term>
1406 <para>Specifies an unique identifier of the ERSPAN v2 engine. Takes an integer in the range
0…
63.
1407 Only used when
<varname>ERSPANVersion=
2</varname>. Defaults to
0.
</para>
1414 <title>[FooOverUDP] Section Options
</title>
1416 <para>The [FooOverUDP] section only applies for
1417 netdevs of kind
<literal>fou
</literal> and accepts the
1418 following keys:
</para>
1420 <variablelist class='network-directives'
>
1422 <term><varname>Encapsulation=
</varname></term>
1424 <para>Specifies the encapsulation mechanism used to store networking packets of various protocols
1425 inside the UDP packets. Supports the following values:
1427 <literal>FooOverUDP
</literal> provides the simplest no-frills model of UDP encapsulation, it simply
1428 encapsulates packets directly in the UDP payload.
<literal>GenericUDPEncapsulation
</literal> is a
1429 generic and extensible encapsulation, it allows encapsulation of packets for any IP protocol and
1430 optional data as part of the encapsulation. For more detailed information see
<ulink
1431 url=
"https://lwn.net/Articles/615044">Generic UDP Encapsulation
</ulink>. Defaults to
1432 <literal>FooOverUDP
</literal>.
1437 <term><varname>Port=
</varname></term>
1439 <para>Specifies the port number where the encapsulated packets will arrive. Those packets will be
1440 removed and manually fed back into the network stack with the encapsulation removed to be sent to
1441 the real destination. This option is mandatory.
</para>
1445 <term><varname>PeerPort=
</varname></term>
1447 <para>Specifies the peer port number. Defaults to unset. Note that when peer port is set
1448 <literal>Peer=
</literal> address is mandatory.
</para>
1452 <term><varname>Protocol=
</varname></term>
1454 <para>The
<varname>Protocol=
</varname> specifies the protocol number of the packets arriving
1455 at the UDP port. When
<varname>Encapsulation=FooOverUDP
</varname>, this field is mandatory
1456 and is not set by default. Takes an IP protocol name such as
<literal>gre
</literal> or
1457 <literal>ipip
</literal>, or an integer within the range
1…
255. When
1458 <varname>Encapsulation=GenericUDPEncapsulation
</varname>, this must not be specified.
</para>
1462 <term><varname>Peer=
</varname></term>
1464 <para>Configures peer IP address. Note that when peer address is set
<literal>PeerPort=
</literal>
1465 is mandatory.
</para>
1469 <term><varname>Local=
</varname></term>
1471 <para>Configures local IP address.
</para>
1478 <title>[Peer] Section Options
</title>
1480 <para>The [Peer] section only applies for
1481 netdevs of kind
<literal>veth
</literal> and accepts the
1482 following keys:
</para>
1484 <variablelist class='network-directives'
>
1486 <term><varname>Name=
</varname></term>
1488 <para>The interface name used when creating the netdev.
1489 This setting is compulsory.
</para>
1493 <term><varname>MACAddress=
</varname></term>
1495 <para>The peer MACAddress, if not set, it is generated in
1496 the same way as the MAC address of the main
1504 <title>[VXCAN] Section Options
</title>
1506 <para>The [VXCAN] section only applies for
1507 netdevs of kind
<literal>vxcan
</literal> and accepts the
1508 following key:
</para>
1510 <variablelist class='network-directives'
>
1512 <term><varname>Peer=
</varname></term>
1514 <para>The peer interface name used when creating the netdev.
1515 This setting is compulsory.
</para>
1522 <title>[Tun] Section Options
</title>
1524 <para>The [Tun] section only applies for
1525 netdevs of kind
<literal>tun
</literal>, and accepts the following
1528 <variablelist class='network-directives'
>
1530 <term><varname>MultiQueue=
</varname></term>
1531 <listitem><para>Takes a boolean. Configures whether
1532 to use multiple file descriptors (queues) to parallelize
1533 packets sending and receiving. Defaults to
1534 <literal>no
</literal>.
</para>
1538 <term><varname>PacketInfo=
</varname></term>
1539 <listitem><para>Takes a boolean. Configures whether
1540 packets should be prepended with four extra bytes (two flag
1541 bytes and two protocol bytes). If disabled, it indicates that
1542 the packets will be pure IP packets. Defaults to
1543 <literal>no
</literal>.
</para>
1547 <term><varname>VNetHeader=
</varname></term>
1548 <listitem><para>Takes a boolean. Configures
1549 IFF_VNET_HDR flag for a tun or tap device. It allows sending
1550 and receiving larger Generic Segmentation Offload (GSO)
1551 packets. This may increase throughput significantly.
1553 <literal>no
</literal>.
</para>
1557 <term><varname>User=
</varname></term>
1558 <listitem><para>User to grant access to the
1559 <filename>/dev/net/tun
</filename> device.
</para>
1563 <term><varname>Group=
</varname></term>
1564 <listitem><para>Group to grant access to the
1565 <filename>/dev/net/tun
</filename> device.
</para>
1569 <term><varname>KeepCarrier=
</varname></term>
1571 <para>Takes a boolean. If enabled, to make the interface maintain its carrier status, the file
1572 descriptor of the interface is kept open. This may be useful to keep the interface in running
1573 state, for example while the backing process is temporarily shutdown. Defaults to
1574 <literal>no
</literal>.
</para>
1581 <title>[Tap] Section Options
</title>
1583 <para>The [Tap] section only applies for
1584 netdevs of kind
<literal>tap
</literal>, and accepts the same keys
1585 as the [Tun] section.
</para>
1589 <title>[WireGuard] Section Options
</title>
1591 <para>The [WireGuard] section accepts the following
1594 <variablelist class='network-directives'
>
1596 <term><varname>PrivateKey=
</varname></term>
1598 <para>The Base64 encoded private key for the interface. It can be
1599 generated using the
<command>wg genkey
</command> command
1600 (see
<citerefentry project=
"wireguard"><refentrytitle>wg
</refentrytitle><manvolnum>8</manvolnum></citerefentry>).
1601 This option or
<varname>PrivateKeyFile=
</varname> is mandatory to use WireGuard.
1602 Note that because this information is secret, you may want to set
1603 the permissions of the .netdev file to be owned by
<literal>root:systemd-network
</literal>
1604 with a
<literal>0640</literal> file mode.
</para>
1608 <term><varname>PrivateKeyFile=
</varname></term>
1610 <para>Takes an absolute path to a file which contains the Base64 encoded private key for the
1611 interface. When this option is specified, then
<varname>PrivateKey=
</varname> is ignored. Note
1612 that the file must be readable by the user
<literal>systemd-network
</literal>, so it should be,
1613 e.g., owned by
<literal>root:systemd-network
</literal> with a
<literal>0640</literal> file mode. If
1614 the path refers to an
<constant>AF_UNIX
</constant> stream socket in the file system a connection is
1615 made to it and the key read from it.
</para>
1619 <term><varname>ListenPort=
</varname></term>
1621 <para>Sets UDP port for listening. Takes either value between
1 and
65535
1622 or
<literal>auto
</literal>. If
<literal>auto
</literal> is specified,
1623 the port is automatically generated based on interface name.
1624 Defaults to
<literal>auto
</literal>.
</para>
1628 <term><varname>FirewallMark=
</varname></term>
1630 <para>Sets a firewall mark on outgoing WireGuard packets from this interface. Takes a number between
1 and
4294967295.
</para>
1634 <term><varname>RouteTable=
</varname></term>
1636 <para>The table identifier for the routes to the addresses specified in the
1637 <varname>AllowedIPs=
</varname>. Takes a negative boolean value, one of the predefined names
1638 <literal>default
</literal>,
<literal>main
</literal>, and
<literal>local
</literal>, names
1639 defined in
<varname>RouteTable=
</varname> in
1640 <citerefentry><refentrytitle>networkd.conf
</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1641 or a number in the range
1…
4294967295. When
<literal>off
</literal> the routes to the
1642 addresses specified in the
<varname>AllowedIPs=
</varname> setting will not be configured.
1643 Defaults to false. This setting will be ignored when the same setting is specified in the
1644 [WireGuardPeer] section.
</para>
1648 <term><varname>RouteMetric=
</varname></term>
1650 <para>The priority of the routes to the addresses specified in the
1651 <varname>AllowedIPs=
</varname>. Takes an integer in the range
0…
4294967295. Defaults to
0
1652 for IPv4 addresses, and
1024 for IPv6 addresses. This setting will be ignored when the same
1653 setting is specified in the [WireGuardPeer] section.
</para>
1660 <title>[WireGuardPeer] Section Options
</title>
1662 <para>The [WireGuardPeer] section accepts the following
1665 <variablelist class='network-directives'
>
1667 <term><varname>PublicKey=
</varname></term>
1669 <para>Sets a Base64 encoded public key calculated by
<command>wg pubkey
</command>
1670 (see
<citerefentry project=
"wireguard"><refentrytitle>wg
</refentrytitle><manvolnum>8</manvolnum></citerefentry>)
1671 from a private key, and usually transmitted out of band to the
1672 author of the configuration file. This option is mandatory for this
1677 <term><varname>PresharedKey=
</varname></term>
1679 <para>Optional preshared key for the interface. It can be generated
1680 by the
<command>wg genpsk
</command> command. This option adds an
1681 additional layer of symmetric-key cryptography to be mixed into the
1682 already existing public-key cryptography, for post-quantum
1684 Note that because this information is secret, you may want to set
1685 the permissions of the .netdev file to be owned by
<literal>root:systemd-network
</literal>
1686 with a
<literal>0640</literal> file mode.
</para>
1690 <term><varname>PresharedKeyFile=
</varname></term>
1692 <para>Takes an absolute path to a file which contains the Base64 encoded preshared key for the
1693 peer. When this option is specified, then
<varname>PresharedKey=
</varname> is ignored. Note that
1694 the file must be readable by the user
<literal>systemd-network
</literal>, so it should be, e.g.,
1695 owned by
<literal>root:systemd-network
</literal> with a
<literal>0640</literal> file mode. If the
1696 path refers to an
<constant>AF_UNIX
</constant> stream socket in the file system a connection is
1697 made to it and the key read from it.
</para>
1701 <term><varname>AllowedIPs=
</varname></term>
1703 <para>Sets a comma-separated list of IP (v4 or v6) addresses with CIDR masks from which this peer
1704 is allowed to send incoming traffic and to which outgoing traffic for this peer is directed. This
1705 setting can be specified multiple times. If an empty string is assigned, then the all previous
1706 assignments are cleared.
</para>
1708 <para>The catch-all
0.0.0.0/
0 may be specified for matching all IPv4 addresses,
1709 and ::/
0 may be specified for matching all IPv6 addresses.
</para>
1711 <para>Note that this only affects
<emphasis>routing inside the network interface itself
</emphasis>,
1712 i.e. the packets that pass through the tunnel itself. To cause packets to be sent via the tunnel in
1713 the first place, an appropriate route needs to be added as well — either in the
1714 <literal>[Routes]
</literal> section on the
<literal>.network
</literal> matching the wireguard
1715 interface, or externally to
<filename>systemd-networkd
</filename>.
</para>
1719 <term><varname>Endpoint=
</varname></term>
1721 <para>Sets an endpoint IP address or hostname, followed by a colon, and then
1722 a port number. IPv6 address must be in the square brackets. For example,
1723 <literal>111.222.333.444:
51820</literal> for IPv4 and
<literal>[
1111:
2222::
3333]:
51820</literal>
1724 for IPv6 address. This endpoint will be updated automatically once to
1725 the most recent source IP address and port of correctly
1726 authenticated packets from the peer at configuration time.
</para>
1730 <term><varname>PersistentKeepalive=
</varname></term>
1732 <para>Sets a seconds interval, between
1 and
65535 inclusive, of how often
1733 to send an authenticated empty packet to the peer for the purpose
1734 of keeping a stateful firewall or NAT mapping valid persistently.
1735 For example, if the interface very rarely sends traffic, but it
1736 might at anytime receive traffic from a peer, and it is behind NAT,
1737 the interface might benefit from having a persistent keepalive
1738 interval of
25 seconds. If set to
0 or
"off", this option is
1739 disabled. By default or when unspecified, this option is off.
1740 Most users will not need this.
</para>
1744 <term><varname>RouteTable=
</varname></term>
1746 <para>The table identifier for the routes to the addresses specified in the
1747 <varname>AllowedIPs=
</varname>. Takes a negative boolean value, one of the predefined names
1748 <literal>default
</literal>,
<literal>main
</literal>, and
<literal>local
</literal>, names
1749 defined in
<varname>RouteTable=
</varname> in
1750 <citerefentry><refentrytitle>networkd.conf
</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1751 or a number in the range
1…
4294967295. Defaults to unset, and the value specified in the
1752 same setting in the [WireGuard] section will be used.
</para>
1756 <term><varname>RouteMetric=
</varname></term>
1758 <para>The priority of the routes to the addresses specified in the
1759 <varname>AllowedIPs=
</varname>. Takes an integer in the range
0…
4294967295. Defaults to
1760 unset, and the value specified in the same setting in the [WireGuard] section will be used.
1768 <title>[Bond] Section Options
</title>
1770 <para>The [Bond] section accepts the following
1773 <variablelist class='network-directives'
>
1775 <term><varname>Mode=
</varname></term>
1777 <para>Specifies one of the bonding policies. The default is
1778 <literal>balance-rr
</literal> (round robin). Possible values are
1779 <literal>balance-rr
</literal>,
1780 <literal>active-backup
</literal>,
1781 <literal>balance-xor
</literal>,
1782 <literal>broadcast
</literal>,
1783 <literal>802.3ad
</literal>,
1784 <literal>balance-tlb
</literal>, and
1785 <literal>balance-alb
</literal>.
1791 <term><varname>TransmitHashPolicy=
</varname></term>
1793 <para>Selects the transmit hash policy to use for slave
1794 selection in balance-xor,
802.3ad, and tlb modes. Possible
1796 <literal>layer2
</literal>,
1797 <literal>layer3+
4</literal>,
1798 <literal>layer2+
3</literal>,
1799 <literal>encap2+
3</literal>, and
1800 <literal>encap3+
4</literal>.
1806 <term><varname>LACPTransmitRate=
</varname></term>
1808 <para>Specifies the rate with which link partner transmits
1809 Link Aggregation Control Protocol Data Unit packets in
1810 802.3ad mode. Possible values are
<literal>slow
</literal>,
1811 which requests partner to transmit LACPDUs every
30 seconds,
1812 and
<literal>fast
</literal>, which requests partner to
1813 transmit LACPDUs every second. The default value is
1814 <literal>slow
</literal>.
</para>
1819 <term><varname>MIIMonitorSec=
</varname></term>
1821 <para>Specifies the frequency that Media Independent
1822 Interface link monitoring will occur. A value of zero
1823 disables MII link monitoring. This value is rounded down to
1824 the nearest millisecond. The default value is
0.
</para>
1829 <term><varname>UpDelaySec=
</varname></term>
1831 <para>Specifies the delay before a link is enabled after a
1832 link up status has been detected. This value is rounded down
1833 to a multiple of
<varname>MIIMonitorSec=
</varname>. The default value is
1839 <term><varname>DownDelaySec=
</varname></term>
1841 <para>Specifies the delay before a link is disabled after a
1842 link down status has been detected. This value is rounded
1843 down to a multiple of
<varname>MIIMonitorSec=
</varname>. The default value is
1849 <term><varname>LearnPacketIntervalSec=
</varname></term>
1851 <para>Specifies the number of seconds between instances where the bonding
1852 driver sends learning packets to each slave peer switch.
1853 The valid range is
1…
0x7fffffff; the default value is
1. This option
1854 has an effect only for the balance-tlb and balance-alb modes.
</para>
1859 <term><varname>AdSelect=
</varname></term>
1861 <para>Specifies the
802.3ad aggregation selection logic to use. Possible values are
1862 <literal>stable
</literal>,
1863 <literal>bandwidth
</literal> and
1864 <literal>count
</literal>.
1870 <term><varname>AdActorSystemPriority=
</varname></term>
1872 <para>Specifies the
802.3ad actor system priority. Takes a number in the range
1…
65535.
</para>
1877 <term><varname>AdUserPortKey=
</varname></term>
1879 <para>Specifies the
802.3ad user defined portion of the port key. Takes a number in the range
1885 <term><varname>AdActorSystem=
</varname></term>
1887 <para>Specifies the
802.3ad system MAC address. This cannot be a null or multicast address.
1893 <term><varname>FailOverMACPolicy=
</varname></term>
1895 <para>Specifies whether the active-backup mode should set all slaves to
1896 the same MAC address at the time of enslavement or, when enabled, to perform special handling of the
1897 bond's MAC address in accordance with the selected policy. The default policy is none.
1899 <literal>none
</literal>,
1900 <literal>active
</literal> and
1901 <literal>follow
</literal>.
1907 <term><varname>ARPValidate=
</varname></term>
1909 <para>Specifies whether or not ARP probes and replies should be
1910 validated in any mode that supports ARP monitoring, or whether
1911 non-ARP traffic should be filtered (disregarded) for link
1912 monitoring purposes. Possible values are
1913 <literal>none
</literal>,
1914 <literal>active
</literal>,
1915 <literal>backup
</literal> and
1916 <literal>all
</literal>.
1922 <term><varname>ARPIntervalSec=
</varname></term>
1924 <para>Specifies the ARP link monitoring frequency. A value of
0 disables ARP monitoring. The
1925 default value is
0, and the default unit seconds.
1931 <term><varname>ARPIPTargets=
</varname></term>
1933 <para>Specifies the IP addresses to use as ARP monitoring peers when
1934 <varname>ARPIntervalSec=
</varname> is greater than
0. These are the targets of the ARP
1935 request sent to determine the health of the link to the targets.
1936 Specify these values in IPv4 dotted decimal format. At least one IP
1937 address must be given for ARP monitoring to function. The
1938 maximum number of targets that can be specified is
16. The
1939 default value is no IP addresses.
1945 <term><varname>ARPAllTargets=
</varname></term>
1947 <para>Specifies the quantity of
<varname>ARPIPTargets=
</varname> that must be reachable
1948 in order for the ARP monitor to consider a slave as being up.
1949 This option affects only active-backup mode for slaves with
1950 ARPValidate enabled. Possible values are
1951 <literal>any
</literal> and
1952 <literal>all
</literal>.
1958 <term><varname>PrimaryReselectPolicy=
</varname></term>
1960 <para>Specifies the reselection policy for the primary slave. This
1961 affects how the primary slave is chosen to become the active slave
1962 when failure of the active slave or recovery of the primary slave
1963 occurs. This option is designed to prevent flip-flopping between
1964 the primary slave and other slaves. Possible values are
1965 <literal>always
</literal>,
1966 <literal>better
</literal> and
1967 <literal>failure
</literal>.
1973 <term><varname>ResendIGMP=
</varname></term>
1975 <para>Specifies the number of IGMP membership reports to be issued after
1976 a failover event. One membership report is issued immediately after
1977 the failover, subsequent packets are sent in each
200ms interval.
1978 The valid range is
0…
255. Defaults to
1. A value of
0
1979 prevents the IGMP membership report from being issued in response
1980 to the failover event.
1986 <term><varname>PacketsPerSlave=
</varname></term>
1988 <para>Specify the number of packets to transmit through a slave before
1989 moving to the next one. When set to
0, then a slave is chosen at
1990 random. The valid range is
0…
65535. Defaults to
1. This option
1991 only has effect when in balance-rr mode.
1997 <term><varname>GratuitousARP=
</varname></term>
1999 <para>Specify the number of peer notifications (gratuitous ARPs and
2000 unsolicited IPv6 Neighbor Advertisements) to be issued after a
2001 failover event. As soon as the link is up on the new slave,
2002 a peer notification is sent on the bonding device and each
2003 VLAN sub-device. This is repeated at each link monitor interval
2004 (ARPIntervalSec or MIIMonitorSec, whichever is active) if the number is
2005 greater than
1. The valid range is
0…
255. The default value is
1.
2006 These options affect only the active-backup mode.
2012 <term><varname>AllSlavesActive=
</varname></term>
2014 <para>Takes a boolean. Specifies that duplicate frames (received on inactive ports)
2015 should be dropped when false, or delivered when true. Normally, bonding will drop
2016 duplicate frames (received on inactive ports), which is desirable for
2017 most users. But there are some times it is nice to allow duplicate
2018 frames to be delivered. The default value is false (drop duplicate frames
2019 received on inactive ports).
2025 <term><varname>DynamicTransmitLoadBalancing=
</varname></term>
2027 <para>Takes a boolean. Specifies if dynamic shuffling of flows is enabled. Applies only
2028 for balance-tlb mode. Defaults to unset.
2034 <term><varname>MinLinks=
</varname></term>
2036 <para>Specifies the minimum number of links that must be active before
2037 asserting carrier. The default value is
0.
2043 <para>For more detail information see
2044 <ulink url=
"https://docs.kernel.org/networking/bonding.html">
2045 Linux Ethernet Bonding Driver HOWTO
</ulink></para>
2049 <title>[Xfrm] Section Options
</title>
2051 <para>The [Xfrm] section accepts the following
2054 <variablelist class='network-directives'
>
2056 <term><varname>InterfaceId=
</varname></term>
2058 <para>Sets the ID/key of the xfrm interface which needs to be associated with a SA/policy.
2059 Can be decimal or hexadecimal, valid range is
1-
0xffffffff. This is mandatory.
</para>
2063 <term><varname>Independent=
</varname></term>
2065 <para>Takes a boolean. If false (the default), the xfrm interface must have an underlying device
2066 which can be used for hardware offloading.
</para>
2071 <para>For more detail information see
2072 <ulink url=
"https://lwn.net/Articles/757391">Virtual XFRM Interfaces
</ulink>.
</para>
2076 <title>[VRF] Section Options
</title>
2077 <para>The [VRF] section only applies for
2078 netdevs of kind
<literal>vrf
</literal> and accepts the
2079 following key:
</para>
2081 <variablelist class='network-directives'
>
2083 <term><varname>Table=
</varname></term>
2085 <para>The numeric routing table identifier. This setting is compulsory.
</para>
2092 <title>[BatmanAdvanced] Section Options
</title>
2094 <para>The [BatmanAdvanced] section only applies for netdevs of kind
<literal>batadv
</literal> and accepts
2095 the following keys:
</para>
2097 <variablelist class='network-directives'
>
2099 <term><varname>GatewayMode=
</varname></term>
2101 <para>Takes one of
<literal>off
</literal>,
<literal>server
</literal>, or
<literal>client
</literal>.
2102 A batman-adv node can either run in server mode (sharing its internet
2103 connection with the mesh) or in client mode (searching for the most suitable internet connection
2104 in the mesh) or having the gateway support turned off entirely (which is the default setting).
2109 <term><varname>Aggregation=
</varname></term>
2111 <para>Takes a boolean value. Enables or disables aggregation of originator messages. Defaults to
2117 <term><varname>BridgeLoopAvoidance=
</varname></term>
2119 <para>Takes a boolean value. Enables or disables avoidance of loops on bridges. Defaults to true.
2124 <term><varname>DistributedArpTable=
</varname></term>
2126 <para>Takes a boolean value. Enables or disables the distributed ARP table. Defaults to true.
</para>
2130 <term><varname>Fragmentation=
</varname></term>
2132 <para>Takes a boolean value. Enables or disables fragmentation. Defaults to true.
</para>
2136 <term><varname>HopPenalty=
</varname></term>
2138 <para>The hop penalty setting allows one to modify
2139 <citerefentry project='mankier'
><refentrytitle>batctl
</refentrytitle><manvolnum>8</manvolnum></citerefentry>
2140 preference for multihop routes vs. short routes. This integer value is applied to the
2141 TQ (Transmit Quality) of each forwarded OGM (Originator Message), thereby propagating the
2142 cost of an extra hop (the packet has to be received and retransmitted which costs airtime).
2143 A higher hop penalty will make it more unlikely that other nodes will choose this node as
2144 intermediate hop towards any given destination. The default hop penalty of '
15' is a reasonable
2145 value for most setups and probably does not need to be changed. However, mobile nodes could
2146 choose a value of
255 (maximum value) to avoid being chosen as a router by other nodes.
2147 The minimum value is
0.
2152 <term><varname>OriginatorIntervalSec=
</varname></term>
2154 <para>The value specifies the interval in seconds, unless another time unit is specified in which
2155 batman-adv floods the network with its protocol information.
2156 See
<citerefentry><refentrytitle>systemd.time
</refentrytitle><manvolnum>7</manvolnum></citerefentry>
2157 for more information.
</para>
2161 <term><varname>GatewayBandwidthDown=
</varname></term>
2163 <para>If the node is a server, this
2164 parameter is used to inform other nodes in the network about
2165 this node's internet connection download bandwidth in bits per second. Just enter any number
2166 suffixed with K, M, G or T (base
1000) and the batman-adv
2167 module will propagate the entered value in the mesh.
</para>
2171 <term><varname>GatewayBandwidthUp=
</varname></term>
2173 <para>If the node is a server, this
2174 parameter is used to inform other nodes in the network about
2175 this node's internet connection upload bandwidth in bits per second. Just enter any number
2176 suffixed with K, M, G or T (base
1000) and the batman-adv
2177 module will propagate the entered value in the mesh.
</para>
2181 <term><varname>RoutingAlgorithm=
</varname></term>
2183 <para>This can be either
<literal>batman-v
</literal> or
<literal>batman-iv
</literal> and describes which routing_algo
2184 of
<citerefentry project='mankier'
><refentrytitle>batctl
</refentrytitle><manvolnum>8</manvolnum></citerefentry> to use. The algorithm
2185 cannot be changed after interface creation. Defaults to
<literal>batman-v
</literal>.
2193 <title>[IPoIB] Section Options
</title>
2194 <para>The [IPoIB] section only applies for netdevs of kind
<literal>ipoib
</literal> and accepts the
2195 following keys:
</para>
2197 <variablelist class='network-directives'
>
2199 <term><varname>PartitionKey=
</varname></term>
2201 <para>Takes an integer in the range
1…
0xffff, except for
0x8000. Defaults to unset, and the
2202 kernel's default is used.
</para>
2206 <varlistentry id='ipoib_mode'
>
2207 <term><varname>Mode=
</varname></term>
2209 <para>Takes one of the special values
<literal>datagram
</literal> or
2210 <literal>connected
</literal>. Defaults to unset, and the kernel's default is used.
</para>
2212 <para>When
<literal>datagram
</literal>, the Infiniband unreliable datagram (UD) transport is
2213 used, and so the interface MTU is equal to the IB L2 MTU minus the IPoIB encapsulation
2214 header (
4 bytes). For example, in a typical IB fabric with a
2K MTU, the IPoIB MTU will be
2215 2048 -
4 =
2044 bytes.
</para>
2217 <para>When
<literal>connected
</literal>, the Infiniband reliable connected (RC) transport is
2218 used. Connected mode takes advantage of the connected nature of the IB transport and allows
2219 an MTU up to the maximal IP packet size of
64K, which reduces the number of IP packets needed
2220 for handling large UDP datagrams, TCP segments, etc and increases the performance for large
2225 <varlistentry id='ipoib_umcast'
>
2226 <term><varname>IgnoreUserspaceMulticastGroup=
</varname></term>
2228 <para>Takes an boolean value. When true, the kernel ignores multicast groups handled by
2229 userspace. Defaults to unset, and the kernel's default is used.
</para>
2236 <title>[WLAN] Section Options
</title>
2237 <para>The [WLAN] section only applies to WLAN interfaces, and accepts the following keys:
</para>
2239 <variablelist class='network-directives'
>
2241 <term><varname>PhysicalDevice=
</varname></term>
2243 <para>Specifies the name or index of the physical WLAN device (e.g.
<literal>0</literal> or
2244 <literal>phy0
</literal>). The list of the physical WLAN devices that exist on the host can be
2245 obtained by
<command>iw phy
</command> command. This option is mandatory.
</para>
2250 <term><varname>Type=
</varname></term>
2252 <para>Specifies the type of the interface. Takes one of the
<literal>ad-hoc
</literal>,
2253 <literal>station
</literal>,
<literal>ap
</literal>,
<literal>ap-vlan
</literal>,
2254 <literal>wds
</literal>,
<literal>monitor
</literal>,
<literal>mesh-point
</literal>,
2255 <literal>p2p-client
</literal>,
<literal>p2p-go
</literal>,
<literal>p2p-device
</literal>,
2256 <literal>ocb
</literal>, and
<literal>nan
</literal>. This option is mandatory.
</para>
2261 <term><varname>WDS=
</varname></term>
2263 <para>Enables the Wireless Distribution System (WDS) mode on the interface. The mode is also
2264 known as the
<literal>4 address mode
</literal>. Takes a boolean value. Defaults to unset, and
2265 the kernel's default will be used.
</para>
2272 <title>Examples
</title>
2274 <title>/etc/systemd/network/
25-bridge.netdev
</title>
2276 <programlisting>[NetDev]
2278 Kind=bridge
</programlisting>
2282 <title>/etc/systemd/network/
25-vlan1.netdev
</title>
2284 <programlisting>[Match]
2292 Id=
1</programlisting>
2295 <title>/etc/systemd/network/
25-ipip.netdev
</title>
2296 <programlisting>[NetDev]
2302 Local=
192.168.223.238
2303 Remote=
192.169.224.239
2304 TTL=
64</programlisting>
2307 <title>/etc/systemd/network/
1-fou-tunnel.netdev
</title>
2308 <programlisting>[NetDev]
2318 <title>/etc/systemd/network/
25-fou-ipip.netdev
</title>
2319 <programlisting>[NetDev]
2326 Remote=
10.65.208.211
2328 FOUDestinationPort=
5555
2332 <title>/etc/systemd/network/
25-tap.netdev
</title>
2333 <programlisting>[NetDev]
2339 PacketInfo=yes
</programlisting> </example>
2342 <title>/etc/systemd/network/
25-sit.netdev
</title>
2343 <programlisting>[NetDev]
2350 Remote=
10.65.223.239</programlisting>
2354 <title>/etc/systemd/network/
25-
6rd.netdev
</title>
2355 <programlisting>[NetDev]
2362 IPv6RapidDeploymentPrefix=
2602::/
24</programlisting>
2366 <title>/etc/systemd/network/
25-gre.netdev
</title>
2367 <programlisting>[NetDev]
2374 Remote=
10.65.223.239</programlisting>
2378 <title>/etc/systemd/network/
25-ip6gre.netdev
</title>
2379 <programlisting>[NetDev]
2384 Key=
123</programlisting>
2388 <title>/etc/systemd/network/
25-vti.netdev
</title>
2390 <programlisting>[NetDev]
2397 Remote=
10.65.223.239</programlisting>
2401 <title>/etc/systemd/network/
25-veth.netdev
</title>
2402 <programlisting>[NetDev]
2407 Name=veth-peer
</programlisting>
2411 <title>/etc/systemd/network/
25-bond.netdev
</title>
2412 <programlisting>[NetDev]
2418 TransmitHashPolicy=layer3+
4
2420 LACPTransmitRate=fast
2425 <title>/etc/systemd/network/
25-dummy.netdev
</title>
2426 <programlisting>[NetDev]
2429 MACAddress=
12:
34:
56:
78:
9a:bc
</programlisting>
2432 <title>/etc/systemd/network/
25-vrf.netdev
</title>
2433 <para>Create a VRF interface with table
42.
</para>
2434 <programlisting>[NetDev]
2439 Table=
42</programlisting>
2443 <title>/etc/systemd/network/
25-macvtap.netdev
</title>
2444 <para>Create a MacVTap device.
</para>
2445 <programlisting>[NetDev]
2451 <title>/etc/systemd/network/
25-wireguard.netdev
</title>
2452 <programlisting>[NetDev]
2457 PrivateKey=EEGlnEPYJV//kbvvIqxKkQwOiS+UENyPncC4bF46ong=
2461 PublicKey=RDf+LSpeEre7YEIKaxg+wbpsNV7du+ktR99uBEtIiCA=
2462 AllowedIPs=fd31:bf08:
57cb::/
48,
192.168.26.0/
24
2463 Endpoint=wireguard.example.com:
51820</programlisting>
2467 <title>/etc/systemd/network/
27-xfrm.netdev
</title>
2468 <programlisting>[NetDev]
2473 Independent=yes
</programlisting>
2478 <title>See Also
</title>
2480 <citerefentry><refentrytitle>systemd
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
2481 <citerefentry><refentrytitle>systemd-networkd
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
2482 <citerefentry><refentrytitle>systemd.link
</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
2483 <citerefentry><refentrytitle>systemd.network
</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
2484 <citerefentry><refentrytitle>systemd-network-generator.service
</refentrytitle><manvolnum>8</manvolnum></citerefentry>