1 <?xml version='
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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+ -->
6 <refentry id=
"systemd.netdev" conditional='ENABLE_NETWORKD'
>
9 <title>systemd.network
</title>
10 <productname>systemd
</productname>
14 <refentrytitle>systemd.netdev
</refentrytitle>
15 <manvolnum>5</manvolnum>
19 <refname>systemd.netdev
</refname>
20 <refpurpose>Virtual Network Device configuration
</refpurpose>
24 <para><filename><replaceable>netdev
</replaceable>.netdev
</filename></para>
28 <title>Description
</title>
30 <para>Network setup is performed by
31 <citerefentry><refentrytitle>systemd-networkd
</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
34 <para>The main Virtual Network Device file must have the extension
<filename>.netdev
</filename>;
35 other extensions are ignored. Virtual network devices are created as soon as networkd is
36 started. If a netdev with the specified name already exists, networkd will use that as-is rather
37 than create its own. Note that the settings of the pre-existing netdev will not be changed by
40 <para>The
<filename>.netdev
</filename> files are read from the files located in the system
41 network directory
<filename>/usr/lib/systemd/network
</filename>, the volatile runtime network
42 directory
<filename>/run/systemd/network
</filename> and the local administration network
43 directory
<filename>/etc/systemd/network
</filename>. All configuration files are collectively
44 sorted and processed in lexical order, regardless of the directories in which they live.
45 However, files with identical filenames replace each other. Files in
<filename>/etc
</filename>
46 have the highest priority, files in
<filename>/run
</filename> take precedence over files with
47 the same name in
<filename>/usr/lib
</filename>. This can be used to override a system-supplied
48 configuration file with a local file if needed. As a special case, an empty file (file size
0)
49 or symlink with the same name pointing to
<filename>/dev/null
</filename> disables the
50 configuration file entirely (it is
"masked").
</para>
52 <para>Along with the netdev file
<filename>foo.netdev
</filename>, a
"drop-in" directory
53 <filename>foo.netdev.d/
</filename> may exist. All files with the suffix
<literal>.conf
</literal>
54 from this directory will be parsed after the file itself is parsed. This is useful to alter or
55 add configuration settings, without having to modify the main configuration file. Each drop-in
56 file must have appropriate section headers.
</para>
58 <para>In addition to
<filename>/etc/systemd/network
</filename>, drop-in
<literal>.d
</literal>
59 directories can be placed in
<filename>/usr/lib/systemd/network
</filename> or
60 <filename>/run/systemd/network
</filename> directories. Drop-in files in
61 <filename>/etc
</filename> take precedence over those in
<filename>/run
</filename> which in turn
62 take precedence over those in
<filename>/usr/lib
</filename>. Drop-in files under any of these
63 directories take precedence over the main netdev file wherever located. (Of course, since
64 <filename>/run
</filename> is temporary and
<filename>/usr/lib
</filename> is for vendors, it is
65 unlikely drop-ins should be used in either of those places.)
</para>
69 <title>Supported netdev kinds
</title>
71 <para>The following kinds of virtual network devices may be
72 configured in
<filename>.netdev
</filename> files:
</para>
75 <title>Supported kinds of virtual network devices
</title>
78 <colspec colname='kind'
/>
79 <colspec colname='explanation'
/>
82 <entry>Description
</entry>
85 <row><entry><varname>bond
</varname></entry>
86 <entry>A bond device is an aggregation of all its slave devices. See
<ulink url=
"https://www.kernel.org/doc/Documentation/networking/bonding.txt">Linux Ethernet Bonding Driver HOWTO
</ulink> for details.Local configuration
</entry></row>
88 <row><entry><varname>bridge
</varname></entry>
89 <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>
91 <row><entry><varname>dummy
</varname></entry>
92 <entry>A dummy device drops all packets sent to it.
</entry></row>
94 <row><entry><varname>gre
</varname></entry>
95 <entry>A Level
3 GRE tunnel over IPv4. See
<ulink url=
"https://tools.ietf.org/html/rfc2784">RFC
2784</ulink> for details.
</entry></row>
97 <row><entry><varname>gretap
</varname></entry>
98 <entry>A Level
2 GRE tunnel over IPv4.
</entry></row>
100 <row><entry><varname>erspan
</varname></entry>
101 <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.
</entry></row>
103 <row><entry><varname>ip6gre
</varname></entry>
104 <entry>A Level
3 GRE tunnel over IPv6.
</entry></row>
106 <row><entry><varname>ip6tnl
</varname></entry>
107 <entry>An IPv4 or IPv6 tunnel over IPv6
</entry></row>
109 <row><entry><varname>ip6gretap
</varname></entry>
110 <entry>A Level
2 GRE tunnel over IPv6.
</entry></row>
112 <row><entry><varname>ipip
</varname></entry>
113 <entry>An IPv4 over IPv4 tunnel.
</entry></row>
115 <row><entry><varname>ipvlan
</varname></entry>
116 <entry>An ipvlan device is a stacked device which receives packets from its underlying device based on IP address filtering.
</entry></row>
118 <row><entry><varname>ipvtap
</varname></entry>
119 <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>
121 <row><entry><varname>macvlan
</varname></entry>
122 <entry>A macvlan device is a stacked device which receives packets from its underlying device based on MAC address filtering.
</entry></row>
124 <row><entry><varname>macvtap
</varname></entry>
125 <entry>A macvtap device is a stacked device which receives packets from its underlying device based on MAC address filtering.
</entry></row>
127 <row><entry><varname>sit
</varname></entry>
128 <entry>An IPv6 over IPv4 tunnel.
</entry></row>
130 <row><entry><varname>tap
</varname></entry>
131 <entry>A persistent Level
2 tunnel between a network device and a device node.
</entry></row>
133 <row><entry><varname>tun
</varname></entry>
134 <entry>A persistent Level
3 tunnel between a network device and a device node.
</entry></row>
136 <row><entry><varname>veth
</varname></entry>
137 <entry>An Ethernet tunnel between a pair of network devices.
</entry></row>
139 <row><entry><varname>vlan
</varname></entry>
140 <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>
142 <row><entry><varname>vti
</varname></entry>
143 <entry>An IPv4 over IPSec tunnel.
</entry></row>
145 <row><entry><varname>vti6
</varname></entry>
146 <entry>An IPv6 over IPSec tunnel.
</entry></row>
148 <row><entry><varname>vxlan
</varname></entry>
149 <entry>A virtual extensible LAN (vxlan), for connecting Cloud computing deployments.
</entry></row>
151 <row><entry><varname>geneve
</varname></entry>
152 <entry>A GEneric NEtwork Virtualization Encapsulation (GENEVE) netdev driver.
</entry></row>
154 <row><entry><varname>l2tp
</varname></entry>
155 <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>
157 <row><entry><varname>macsec
</varname></entry>
158 <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>
160 <row><entry><varname>vrf
</varname></entry>
161 <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>
163 <row><entry><varname>vcan
</varname></entry>
164 <entry>The virtual CAN driver (vcan). Similar to the network loopback devices, vcan offers a virtual local CAN interface.
</entry></row>
166 <row><entry><varname>vxcan
</varname></entry>
167 <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.
170 <row><entry><varname>wireguard
</varname></entry>
171 <entry>WireGuard Secure Network Tunnel.
</entry></row>
173 <row><entry><varname>netdevsim
</varname></entry>
174 <entry>A simulator. This simulated networking device is used for testing various networking APIs and at this time is particularly focused on testing hardware offloading related interfaces.
</entry></row>
176 <row><entry><varname>nlmon
</varname></entry>
177 <entry>A Netlink monitor device. Use an nlmon device when you want to monitor system Netlink messages.
</entry></row>
179 <row><entry><varname>fou
</varname></entry>
180 <entry>Foo-over-UDP tunneling.
</entry></row>
182 <row><entry><varname>xfrm
</varname></entry>
183 <entry>A virtual tunnel interface like vti/vti6 but with several advantages.
</entry></row>
185 <row><entry><varname>ifb
</varname></entry>
186 <entry> The Intermediate Functional Block (ifb) pseudo network interface acts as a QoS concentrator for multiple different sources of traffic.
</entry></row>
195 <title>[Match] Section Options
</title>
197 <para>A virtual network device is only created if the
198 <literal>[Match]
</literal> section matches the current
199 environment, or if the section is empty. The following keys are
202 <variablelist class='network-directives'
>
204 <term><varname>Host=
</varname></term>
206 <para>Matches against the hostname or machine ID of the host. See
207 <literal>ConditionHost=
</literal> in
208 <citerefentry><refentrytitle>systemd.unit
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
209 for details. When prefixed with an exclamation mark (
<literal>!
</literal>), the result is negated.
210 If an empty string is assigned, then previously assigned value is cleared.
215 <term><varname>Virtualization=
</varname></term>
217 <para>Checks whether the system is executed in a virtualized environment and optionally test
218 whether it is a specific implementation. See
<literal>ConditionVirtualization=
</literal> in
219 <citerefentry><refentrytitle>systemd.unit
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
220 for details. When prefixed with an exclamation mark (
<literal>!
</literal>), the result is negated.
221 If an empty string is assigned, then previously assigned value is cleared.
226 <term><varname>KernelCommandLine=
</varname></term>
228 <para>Checks whether a specific kernel command line option is set. See
229 <literal>ConditionKernelCommandLine=
</literal> in
230 <citerefentry><refentrytitle>systemd.unit
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
231 for details. When prefixed with an exclamation mark (
<literal>!
</literal>), the result is negated.
232 If an empty string is assigned, then previously assigned value is cleared.
237 <term><varname>KernelVersion=
</varname></term>
239 <para>Checks whether the kernel version (as reported by
<command>uname -r
</command>) matches a
240 certain expression. See
<literal>ConditionKernelVersion=
</literal> in
241 <citerefentry><refentrytitle>systemd.unit
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
242 for details. When prefixed with an exclamation mark (
<literal>!
</literal>), the result is negated.
243 If an empty string is assigned, then previously assigned value is cleared.
248 <term><varname>Architecture=
</varname></term>
250 <para>Checks whether the system is running on a specific architecture. See
251 <literal>ConditionArchitecture=
</literal> in
252 <citerefentry><refentrytitle>systemd.unit
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
253 for details. When prefixed with an exclamation mark (
<literal>!
</literal>), the result is negated.
254 If an empty string is assigned, then previously assigned value is cleared.
262 <title>[NetDev] Section Options
</title>
264 <para>The
<literal>[NetDev]
</literal> section accepts the
265 following keys:
</para>
267 <variablelist class='network-directives'
>
269 <term><varname>Description=
</varname></term>
271 <para>A free-form description of the netdev.
</para>
275 <term><varname>Name=
</varname></term>
277 <para>The interface name used when creating the netdev.
278 This option is compulsory.
</para>
282 <term><varname>Kind=
</varname></term>
284 <para>The netdev kind. This option is compulsory. See the
285 <literal>Supported netdev kinds
</literal> section for the
290 <term><varname>MTUBytes=
</varname></term>
292 <para>The maximum transmission unit in bytes to set for the device. The usual suffixes K, M, G,
293 are supported and are understood to the base of
1024. For
<literal>tun
</literal> or
294 <literal>tap
</literal> devices,
<varname>MTUBytes=
</varname> setting is not currently supported in
295 <literal>[NetDev]
</literal> section. Please specify it in
<literal>[Link]
</literal> section of
297 <citerefentry><refentrytitle>systemd.network
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
302 <term><varname>MACAddress=
</varname></term>
304 <para>The MAC address to use for the device. For
<literal>tun
</literal> or
<literal>tap
</literal>
305 devices, setting
<varname>MACAddress=
</varname> in the
<literal>[NetDev]
</literal> section is not
306 supported. Please specify it in
<literal>[Link]
</literal> section of the corresponding
307 <citerefentry><refentrytitle>systemd.network
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
308 file. If this option is not set,
<literal>vlan
</literal> devices inherit the MAC address of the
309 physical interface. For other kind of netdevs, if this option is not set, then MAC address is
310 generated based on the interface name and the
311 <citerefentry><refentrytitle>machine-id
</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
319 <title>[Bridge] Section Options
</title>
321 <para>The
<literal>[Bridge]
</literal> section only applies for
322 netdevs of kind
<literal>bridge
</literal>, and accepts the
323 following keys:
</para>
325 <variablelist class='network-directives'
>
327 <term><varname>HelloTimeSec=
</varname></term>
329 <para>HelloTimeSec specifies the number of seconds between two hello packets
330 sent out by the root bridge and the designated bridges. Hello packets are
331 used to communicate information about the topology throughout the entire
332 bridged local area network.
</para>
336 <term><varname>MaxAgeSec=
</varname></term>
338 <para>MaxAgeSec specifies the number of seconds of maximum message age.
339 If the last seen (received) hello packet is more than this number of
340 seconds old, the bridge in question will start the takeover procedure
341 in attempt to become the Root Bridge itself.
</para>
345 <term><varname>ForwardDelaySec=
</varname></term>
347 <para>ForwardDelaySec specifies the number of seconds spent in each
348 of the Listening and Learning states before the Forwarding state is entered.
</para>
352 <term><varname>AgeingTimeSec=
</varname></term>
354 <para>This specifies the number of seconds a MAC Address will be kept in
355 the forwarding database after having a packet received from this MAC Address.
</para>
359 <term><varname>Priority=
</varname></term>
361 <para>The priority of the bridge. An integer between
0 and
65535. A lower value
362 means higher priority. The bridge having the lowest priority will be elected as root bridge.
</para>
366 <term><varname>GroupForwardMask=
</varname></term>
368 <para>A
16-bit bitmask represented as an integer which allows forwarding of link
369 local frames with
802.1D reserved addresses (
01:
80:C2:
00:
00:
0X). A logical AND
370 is performed between the specified bitmask and the exponentiation of
2^X, the
371 lower nibble of the last octet of the MAC address. For example, a value of
8
372 would allow forwarding of frames addressed to
01:
80:C2:
00:
00:
03 (
802.1X PAE).
</para>
376 <term><varname>DefaultPVID=
</varname></term>
378 <para>This specifies the default port VLAN ID of a newly attached bridge port.
379 Set this to an integer in the range
1–
4094 or
<literal>none
</literal> to disable the PVID.
</para>
383 <term><varname>MulticastQuerier=
</varname></term>
385 <para>Takes a boolean. This setting controls the IFLA_BR_MCAST_QUERIER option in the kernel.
386 If enabled, the kernel will send general ICMP queries from a zero source address.
387 This feature should allow faster convergence on startup, but it causes some
388 multicast-aware switches to misbehave and disrupt forwarding of multicast packets.
389 When unset, the kernel's default will be used.
394 <term><varname>MulticastSnooping=
</varname></term>
396 <para>Takes a boolean. This setting controls the IFLA_BR_MCAST_SNOOPING option in the kernel.
397 If enabled, IGMP snooping monitors the Internet Group Management Protocol (IGMP) traffic
398 between hosts and multicast routers. When unset, the kernel's default will be used.
403 <term><varname>VLANFiltering=
</varname></term>
405 <para>Takes a boolean. This setting controls the IFLA_BR_VLAN_FILTERING option in the kernel.
406 If enabled, the bridge will be started in VLAN-filtering mode. When unset, the kernel's default will be used.
411 <term><varname>STP=
</varname></term>
413 <para>Takes a boolean. This enables the bridge's Spanning Tree Protocol (STP).
414 When unset, the kernel's default will be used.
419 <term><varname>MulticastIGMPVersion=
</varname></term>
421 <para>Allows changing bridge's multicast Internet Group Management Protocol (IGMP) version.
422 Takes an integer
2 or
3. When unset, the kernel's default will be used.
430 <title>[VLAN] Section Options
</title>
432 <para>The
<literal>[VLAN]
</literal> section only applies for
433 netdevs of kind
<literal>vlan
</literal>, and accepts the
434 following key:
</para>
436 <variablelist class='network-directives'
>
438 <term><varname>Id=
</varname></term>
440 <para>The VLAN ID to use. An integer in the range
0–
4094.
441 This option is compulsory.
</para>
445 <term><varname>GVRP=
</varname></term>
447 <para>Takes a boolean. The Generic VLAN Registration Protocol (GVRP) is a protocol that
448 allows automatic learning of VLANs on a network.
449 When unset, the kernel's default will be used.
454 <term><varname>MVRP=
</varname></term>
456 <para>Takes a boolean. Multiple VLAN Registration Protocol (MVRP) formerly known as GARP VLAN
457 Registration Protocol (GVRP) is a standards-based Layer
2 network protocol,
458 for automatic configuration of VLAN information on switches. It was defined
459 in the
802.1ak amendment to
802.1Q-
2005. When unset, the kernel's default will be used.
464 <term><varname>LooseBinding=
</varname></term>
466 <para>Takes a boolean. The VLAN loose binding mode, in which only the operational state is passed
467 from the parent to the associated VLANs, but the VLAN device state is not changed.
468 When unset, the kernel's default will be used.
</para>
472 <term><varname>ReorderHeader=
</varname></term>
474 <para>Takes a boolean. The VLAN reorder header is set VLAN interfaces behave like physical interfaces.
475 When unset, the kernel's default will be used.
</para>
482 <title>[MACVLAN] Section Options
</title>
484 <para>The
<literal>[MACVLAN]
</literal> 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>, and
496 <literal>passthru
</literal>.
504 <title>[MACVTAP] Section Options
</title>
506 <para>The
<literal>[MACVTAP]
</literal> section applies for
507 netdevs of kind
<literal>macvtap
</literal> and accepts the
508 same key as
<literal>[MACVLAN]
</literal>.
</para>
512 <title>[IPVLAN] Section Options
</title>
514 <para>The
<literal>[IPVLAN]
</literal> section only applies for
515 netdevs of kind
<literal>ipvlan
</literal>, and accepts the
516 following key:
</para>
518 <variablelist class='network-directives'
>
520 <term><varname>Mode=
</varname></term>
522 <para>The IPVLAN mode to use. The supported options are
523 <literal>L2
</literal>,
<literal>L3
</literal> and
<literal>L3S
</literal>.
528 <term><varname>Flags=
</varname></term>
530 <para>The IPVLAN flags to use. The supported options are
531 <literal>bridge
</literal>,
<literal>private
</literal> and
<literal>vepa
</literal>.
539 <title>[IPVTAP] Section Options
</title>
541 <para>The
<literal>[IPVTAP]
</literal> section only applies for
542 netdevs of kind
<literal>ipvtap
</literal> and accepts the
543 same key as
<literal>[IPVLAN]
</literal>.
</para>
547 <title>[VXLAN] Section Options
</title>
549 <para>The
<literal>[VXLAN]
</literal> section only applies for
550 netdevs of kind
<literal>vxlan
</literal>, and accepts the
551 following keys:
</para>
553 <variablelist class='network-directives'
>
555 <term><varname>VNI=
</varname></term>
557 <para>The VXLAN Network Identifier (or VXLAN Segment ID). Takes a number in the range
1-
16777215.
</para>
561 <term><varname>Remote=
</varname></term>
563 <para>Configures destination IP address.
</para>
567 <term><varname>Local=
</varname></term>
569 <para>Configures local IP address.
</para>
573 <term><varname>Group=
</varname></term>
575 <para>Configures VXLAN multicast group IP address. All members of a VXLAN must use the same multicast group address.
</para>
579 <term><varname>TOS=
</varname></term>
581 <para>The Type Of Service byte value for a vxlan interface.
</para>
585 <term><varname>TTL=
</varname></term>
587 <para>A fixed Time To Live N on Virtual eXtensible Local Area Network packets.
588 Takes
<literal>inherit
</literal> or a number in the range
0–
255.
0 is a special
589 value meaning inherit the inner protocol's TTL value.
<literal>inherit
</literal>
590 means that it will inherit the outer protocol's TTL value.
</para>
594 <term><varname>MacLearning=
</varname></term>
596 <para>Takes a boolean. When true, enables dynamic MAC learning
597 to discover remote MAC addresses.
</para>
601 <term><varname>FDBAgeingSec=
</varname></term>
603 <para>The lifetime of Forwarding Database entry learnt by
604 the kernel, in seconds.
</para>
608 <term><varname>MaximumFDBEntries=
</varname></term>
610 <para>Configures maximum number of FDB entries.
</para>
614 <term><varname>ReduceARPProxy=
</varname></term>
616 <para>Takes a boolean. When true, bridge-connected VXLAN tunnel
617 endpoint answers ARP requests from the local bridge on behalf
618 of remote Distributed Overlay Virtual Ethernet
619 <ulink url=
"https://en.wikipedia.org/wiki/Distributed_Overlay_Virtual_Ethernet">
620 (DVOE)
</ulink> clients. Defaults to false.
</para>
624 <term><varname>L2MissNotification=
</varname></term>
626 <para>Takes a boolean. When true, enables netlink LLADDR miss
627 notifications.
</para>
631 <term><varname>L3MissNotification=
</varname></term>
633 <para>Takes a boolean. When true, enables netlink IP address miss
634 notifications.
</para>
638 <term><varname>RouteShortCircuit=
</varname></term>
640 <para>Takes a boolean. When true, route short circuiting is turned
645 <term><varname>UDPChecksum=
</varname></term>
647 <para>Takes a boolean. When true, transmitting UDP checksums when doing VXLAN/IPv4 is turned on.
</para>
651 <term><varname>UDP6ZeroChecksumTx=
</varname></term>
653 <para>Takes a boolean. When true, sending zero checksums in VXLAN/IPv6 is turned on.
</para>
657 <term><varname>UDP6ZeroChecksumRx=
</varname></term>
659 <para>Takes a boolean. When true, receiving zero checksums in VXLAN/IPv6 is turned on.
</para>
663 <term><varname>RemoteChecksumTx=
</varname></term>
665 <para>Takes a boolean. When true, remote transmit checksum offload of VXLAN is turned on.
</para>
669 <term><varname>RemoteChecksumRx=
</varname></term>
671 <para>Takes a boolean. When true, remote receive checksum offload in VXLAN is turned on.
</para>
675 <term><varname>GroupPolicyExtension=
</varname></term>
677 <para>Takes a boolean. When true, it enables Group Policy VXLAN extension security label mechanism
678 across network peers based on VXLAN. For details about the Group Policy VXLAN, see the
679 <ulink url=
"https://tools.ietf.org/html/draft-smith-vxlan-group-policy">
680 VXLAN Group Policy
</ulink> document. Defaults to false.
</para>
684 <term><varname>GenericProtocolExtension=
</varname></term>
686 <para>Takes a boolean. When true, Generic Protocol Extension extends the existing VXLAN protocol
687 to provide protocol typing, OAM, and versioning capabilities. For details about the VXLAN GPE
688 Header, see the
<ulink url=
"https://tools.ietf.org/html/draft-ietf-nvo3-vxlan-gpe-07">
689 Generic Protocol Extension for VXLAN
</ulink> document. If destination port is not specified and
690 Generic Protocol Extension is set then default port of
4790 is used. Defaults to false.
</para>
694 <term><varname>DestinationPort=
</varname></term>
696 <para>Configures the default destination UDP port on a per-device basis.
697 If destination port is not specified then Linux kernel default will be used.
698 Set destination port
4789 to get the IANA assigned value. If not set or if the
699 destination port is assigned the empty string the default port of
4789 is used.
</para>
703 <term><varname>PortRange=
</varname></term>
705 <para>Configures VXLAN port range. VXLAN bases source
706 UDP port based on flow to help the receiver to be able
707 to load balance based on outer header flow. It
708 restricts the port range to the normal UDP local
709 ports, and allows overriding via configuration.
</para>
713 <term><varname>FlowLabel=
</varname></term>
715 <para>Specifies the flow label to use in outgoing packets.
716 The valid range is
0-
1048575.
721 <term><varname>IPDoNotFragment=
</varname></term>
723 <para>Allows setting the IPv4 Do not Fragment (DF) bit in outgoing packets, or to inherit its
724 value from the IPv4 inner header. Takes a boolean value, or
<literal>inherit
</literal>. Set
725 to
<literal>inherit
</literal> if the encapsulated protocol is IPv6. When unset, the kernel's
726 default will be used.
</para>
733 <title>[GENEVE] Section Options
</title>
735 <para>The
<literal>[GENEVE]
</literal> section only applies for
736 netdevs of kind
<literal>geneve
</literal>, and accepts the
737 following keys:
</para>
739 <variablelist class='network-directives'
>
741 <term><varname>Id=
</varname></term>
743 <para>Specifies the Virtual Network Identifier (VNI) to use. Ranges [
0-
16777215]. This field is mandatory.
</para>
747 <term><varname>Remote=
</varname></term>
749 <para>Specifies the unicast destination IP address to use in outgoing packets.
</para>
753 <term><varname>TOS=
</varname></term>
755 <para>Specifies the TOS value to use in outgoing packets. Ranges [
1-
255].
</para>
759 <term><varname>TTL=
</varname></term>
761 <para>Accepts the same key in
<literal>[VXLAN]
</literal> section except when unset or
762 set to
0, the kernel's default will be used meaning that packets TTL will be set from
763 <filename>/proc/sys/net/ipv4/ip_default_ttl
</filename>.
</para>
767 <term><varname>UDPChecksum=
</varname></term>
769 <para>Takes a boolean. When true, specifies if UDP checksum is calculated for transmitted packets over IPv4.
</para>
773 <term><varname>UDP6ZeroChecksumTx=
</varname></term>
775 <para>Takes a boolean. When true, skip UDP checksum calculation for transmitted packets over IPv6.
</para>
779 <term><varname>UDP6ZeroChecksumRx=
</varname></term>
781 <para>Takes a boolean. When true, allows incoming UDP packets over IPv6 with zero checksum field.
</para>
785 <term><varname>DestinationPort=
</varname></term>
787 <para>Specifies destination port. Defaults to
6081. If not set or assigned the empty string, the default
788 port of
6081 is used.
</para>
792 <term><varname>FlowLabel=
</varname></term>
794 <para>Specifies the flow label to use in outgoing packets.
</para>
798 <term><varname>IPDoNotFragment=
</varname></term>
800 <para>Accepts the same key in
<literal>[VXLAN]
</literal> section.
</para>
807 <title>[L2TP] Section Options
</title>
809 <para>The
<literal>[L2TP]
</literal> section only applies for
810 netdevs of kind
<literal>l2tp
</literal>, and accepts the
811 following keys:
</para>
813 <variablelist class='network-directives'
>
815 <term><varname>TunnelId=
</varname></term>
817 <para>Specifies the tunnel id. The value used must match the
<literal>PeerTunnelId=
</literal> value being used at the peer.
818 Ranges a number between
1 and
4294967295). This option is compulsory.
</para>
822 <term><varname>PeerTunnelId=
</varname></term>
824 <para>Specifies the peer tunnel id. The value used must match the
<literal>PeerTunnelId=
</literal> value being used at the peer.
825 Ranges a number between
1 and
4294967295). This option is compulsory.
</para>
829 <term><varname>Remote=
</varname></term>
831 <para>Specifies the IP address of the remote peer. This option is compulsory.
</para>
835 <term><varname>Local=
</varname></term>
837 <para>Specifies the IP address of the local interface. Takes an IP address, or the special values
838 <literal>auto
</literal>,
<literal>static
</literal>, or
<literal>dynamic
</literal>. When an address
839 is set, then the local interface must have the address. If
<literal>auto
</literal>, then one of the
840 addresses on the local interface is used. Similarly, if
<literal>static
</literal> or
841 <literal>dynamic
</literal> is set, then one of the static or dynamic addresses on the local
842 interface is used. Defaults to
<literal>auto
</literal>.
</para>
846 <term><varname>EncapsulationType=
</varname></term>
848 <para>Specifies the encapsulation type of the tunnel. Takes one of
<literal>udp
</literal> or
<literal>ip
</literal>.
</para>
852 <term><varname>UDPSourcePort=
</varname></term>
854 <para>Specifies the UDP source port to be used for the tunnel. When UDP encapsulation is selected it's mandotory. Ignored when ip
855 encapsulation is selected.
</para>
859 <term><varname>DestinationPort=
</varname></term>
861 <para>Specifies destination port. When UDP encapsulation is selected it's mandotory. Ignored when ip
862 encapsulation is selected.
</para>
866 <term><varname>UDPChecksum=
</varname></term>
868 <para>Takes a boolean. When true, specifies if UDP checksum is calculated for transmitted packets over IPv4.
</para>
872 <term><varname>UDP6ZeroChecksumTx=
</varname></term>
874 <para>Takes a boolean. When true, skip UDP checksum calculation for transmitted packets over IPv6.
</para>
878 <term><varname>UDP6ZeroChecksumRx=
</varname></term>
880 <para>Takes a boolean. When true, allows incoming UDP packets over IPv6 with zero checksum field.
</para>
887 <title>[L2TPSession] Section Options
</title>
889 <para>The
<literal>[L2TPSession]
</literal> section only applies for
890 netdevs of kind
<literal>l2tp
</literal>, and accepts the
891 following keys:
</para>
892 <variablelist class='network-directives'
>
894 <term><varname>Name=
</varname></term>
896 <para>Specifies the name of the session. This option is compulsory.
</para>
900 <term><varname>SessionId=
</varname></term>
902 <para>Specifies the session id. The value used must match the
<literal>SessionId=
</literal> value being used at the peer.
903 Ranges a number between
1 and
4294967295). This option is compulsory.
</para>
907 <term><varname>PeerSessionId=
</varname></term>
909 <para>Specifies the peer session id. The value used must match the
<literal>PeerSessionId=
</literal> value being used at the peer.
910 Ranges a number between
1 and
4294967295). This option is compulsory.
</para>
914 <term><varname>Layer2SpecificHeader=
</varname></term>
916 <para>Specifies layer2specific header type of the session. One of
<literal>none
</literal> or
<literal>default
</literal>. Defaults to
<literal>default
</literal>.
</para>
923 <title>[MACsec] Section Options
</title>
925 <para>The
<literal>[MACsec]
</literal> section only applies for network devices of kind
926 <literal>macsec
</literal>, and accepts the following keys:
</para>
928 <variablelist class='network-directives'
>
930 <term><varname>Port=
</varname></term>
932 <para>Specifies the port to be used for the MACsec transmit channel. The port is used to make
933 secure channel identifier (SCI). Takes a value between
1 and
65535. Defaults to unset.
938 <term><varname>Encrypt=
</varname></term>
940 <para>Takes a boolean. When true, enable encryption. Defaults to unset.
</para>
947 <title>[MACsecReceiveChannel] Section Options
</title>
948 <para>The
<literal>[MACsecReceiveChannel]
</literal> section only applies for network devices of
949 kind
<literal>macsec
</literal>, and accepts the following keys:
</para>
951 <variablelist class='network-directives'
>
953 <term><varname>Port=
</varname></term>
955 <para>Specifies the port to be used for the MACsec receive channel. The port is used to make
956 secure channel identifier (SCI). Takes a value between
1 and
65535. This option is
957 compulsory, and is not set by default.
</para>
961 <term><varname>MACAddress=
</varname></term>
963 <para>Specifies the MAC address to be used for the MACsec receive channel. The MAC address
964 used to make secure channel identifier (SCI). This option is compulsory, and is not set by
972 <title>[MACsecTransmitAssociation] Section Options
</title>
974 <para>The
<literal>[MACsecTransmitAssociation]
</literal> section only applies for network devices
975 of kind
<literal>macsec
</literal>, and accepts the following keys:
</para>
977 <variablelist class='network-directives'
>
979 <term><varname>PacketNumber=
</varname></term>
981 <para>Specifies the packet number to be used for replay protection and the construction of
982 the initialization vector (along with the secure channel identifier [SCI]). Takes a value
983 between
1-
4,
294,
967,
295. Defaults to unset.
988 <term><varname>KeyId=
</varname></term>
990 <para>Specifies the identification for the key. Takes a number between
0-
255. This option
991 is compulsory, and is not set by default.
</para>
995 <term><varname>Key=
</varname></term>
997 <para>Specifies the encryption key used in the transmission channel. The same key must be
998 configured on the peer’s matching receive channel. This option is compulsory, and is not set
999 by default. Takes a
128-bit key encoded in a hexadecimal string, for example
1000 <literal>dffafc8d7b9a43d5b9a3dfbbf6a30c16
</literal>.
</para>
1004 <term><varname>KeyFile=
</varname></term>
1006 <para>Takes a absolute path to a file which contains a
128-bit key encoded in a hexadecimal
1007 string, which will be used in the transmission channel. When this option is specified,
1008 <varname>Key=
</varname> is ignored. Note that the file must be readable by the user
1009 <literal>systemd-network
</literal>, so it should be, e.g., owned by
1010 <literal>root:systemd-network
</literal> with a
<literal>0640</literal> file mode.
</para>
1014 <term><varname>Activate=
</varname></term>
1016 <para>Takes a boolean. If enabled, then the security association is activated. Defaults to
1021 <term><varname>UseForEncoding=
</varname></term>
1023 <para>Takes a boolean. If enabled, then the security association is used for encoding. Only
1024 one
<literal>[MACsecTransmitAssociation]
</literal> section can enable this option. When enabled,
1025 <varname>Activate=yes
</varname> is implied. Defaults to unset.
</para>
1032 <title>[MACsecReceiveAssociation] Section Options
</title>
1034 <para>The
<literal>[MACsecReceiveAssociation]
</literal> section only applies for
1035 network devices of kind
<literal>macsec
</literal>, and accepts the
1036 following keys:
</para>
1038 <variablelist class='network-directives'
>
1040 <term><varname>Port=
</varname></term>
1042 <para>Accepts the same key in
<literal>[MACsecReceiveChannel]
</literal> section.
</para>
1046 <term><varname>MACAddress=
</varname></term>
1048 <para>Accepts the same key in
<literal>[MACsecReceiveChannel]
</literal> section.
</para>
1052 <term><varname>PacketNumber=
</varname></term>
1054 <para>Accepts the same key in
<literal>[MACsecTransmitAssociation]
</literal> section.
</para>
1058 <term><varname>KeyId=
</varname></term>
1060 <para>Accepts the same key in
<literal>[MACsecTransmitAssociation]
</literal> section.
</para>
1064 <term><varname>Key=
</varname></term>
1066 <para>Accepts the same key in
<literal>[MACsecTransmitAssociation]
</literal> section.
</para>
1070 <term><varname>KeyFile=
</varname></term>
1072 <para>Accepts the same key in
<literal>[MACsecTransmitAssociation]
</literal> section.
</para>
1076 <term><varname>Activate=
</varname></term>
1078 <para>Accepts the same key in
<literal>[MACsecTransmitAssociation]
</literal> section.
</para>
1085 <title>[Tunnel] Section Options
</title>
1087 <para>The
<literal>[Tunnel]
</literal> section only applies for
1089 <literal>ipip
</literal>,
1090 <literal>sit
</literal>,
1091 <literal>gre
</literal>,
1092 <literal>gretap
</literal>,
1093 <literal>ip6gre
</literal>,
1094 <literal>ip6gretap
</literal>,
1095 <literal>vti
</literal>,
1096 <literal>vti6
</literal>,
1097 <literal>ip6tnl
</literal>, and
1098 <literal>erspan
</literal> and accepts
1099 the following keys:
</para>
1101 <variablelist class='network-directives'
>
1103 <term><varname>Local=
</varname></term>
1105 <para>A static local address for tunneled packets. It must be an address on another interface of
1106 this host, or the special value
<literal>any
</literal>.
</para>
1110 <term><varname>Remote=
</varname></term>
1112 <para>The remote endpoint of the tunnel. Takes an IP address or the special value
1113 <literal>any
</literal>.
</para>
1117 <term><varname>TOS=
</varname></term>
1119 <para>The Type Of Service byte value for a tunnel interface.
1120 For details about the TOS, see the
1121 <ulink url=
"http://tools.ietf.org/html/rfc1349"> Type of
1122 Service in the Internet Protocol Suite
</ulink> document.
1127 <term><varname>TTL=
</varname></term>
1129 <para>A fixed Time To Live N on tunneled packets. N is a
1130 number in the range
1–
255.
0 is a special value meaning that
1131 packets inherit the TTL value. The default value for IPv4
1132 tunnels is: inherit. The default value for IPv6 tunnels is
1137 <term><varname>DiscoverPathMTU=
</varname></term>
1139 <para>Takes a boolean. When true, enables Path MTU Discovery on
1144 <term><varname>IPv6FlowLabel=
</varname></term>
1146 <para>Configures the
20-bit flow label (see
<ulink url=
"https://tools.ietf.org/html/rfc6437">
1147 RFC
6437</ulink>) field in the IPv6 header (see
<ulink url=
"https://tools.ietf.org/html/rfc2460">
1148 RFC
2460</ulink>), which is used by a node to label packets of a flow.
1149 It is only used for IPv6 tunnels.
1150 A flow label of zero is used to indicate packets that have
1152 It can be configured to a value in the range
0–
0xFFFFF, or be
1153 set to
<literal>inherit
</literal>, in which case the original flowlabel is used.
</para>
1157 <term><varname>CopyDSCP=
</varname></term>
1159 <para>Takes a boolean. When true, the Differentiated Service Code
1160 Point (DSCP) field will be copied to the inner header from
1161 outer header during the decapsulation of an IPv6 tunnel
1162 packet. DSCP is a field in an IP packet that enables different
1163 levels of service to be assigned to network traffic.
1164 Defaults to
<literal>no
</literal>.
1169 <term><varname>EncapsulationLimit=
</varname></term>
1171 <para>The Tunnel Encapsulation Limit option specifies how many additional
1172 levels of encapsulation are permitted to be prepended to the packet.
1173 For example, a Tunnel Encapsulation Limit option containing a limit
1174 value of zero means that a packet carrying that option may not enter
1175 another tunnel before exiting the current tunnel.
1176 (see
<ulink url=
"https://tools.ietf.org/html/rfc2473#section-4.1.1"> RFC
2473</ulink>).
1177 The valid range is
0–
255 and
<literal>none
</literal>. Defaults to
4.
1182 <term><varname>Key=
</varname></term>
1184 <para>The
<varname>Key=
</varname> parameter specifies the same key to use in
1185 both directions (
<varname>InputKey=
</varname> and
<varname>OutputKey=
</varname>).
1186 The
<varname>Key=
</varname> is either a number or an IPv4 address-like dotted quad.
1187 It is used as mark-configured SAD/SPD entry as part of the lookup key (both in data
1188 and control path) in ip xfrm (framework used to implement IPsec protocol).
1189 See
<ulink url=
"http://man7.org/linux/man-pages/man8/ip-xfrm.8.html">
1190 ip-xfrm — transform configuration
</ulink> for details. It is only used for VTI/VTI6,
1191 GRE, GRETAP, and ERSPAN tunnels.
</para>
1195 <term><varname>InputKey=
</varname></term>
1197 <para>The
<varname>InputKey=
</varname> parameter specifies the key to use for input.
1198 The format is same as
<varname>Key=
</varname>. It is only used for VTI/VTI6, GRE, GRETAP,
1199 and ERSPAN tunnels.
</para>
1203 <term><varname>OutputKey=
</varname></term>
1205 <para>The
<varname>OutputKey=
</varname> parameter specifies the key to use for output.
1206 The format is same as
<varname>Key=
</varname>. It is only used for VTI/VTI6, GRE, GRETAP,
1207 and ERSPAN tunnels.
</para>
1211 <term><varname>Mode=
</varname></term>
1213 <para>An
<literal>ip6tnl
</literal> tunnel can be in one of three
1215 <literal>ip6ip6
</literal> for IPv6 over IPv6,
1216 <literal>ipip6
</literal> for IPv4 over IPv6 or
1217 <literal>any
</literal> for either.
1222 <term><varname>Independent=
</varname></term>
1224 <para>Takes a boolean. When true tunnel does not require .network file. Created as
"tunnel@NONE".
1225 Defaults to
<literal>false
</literal>.
1230 <term><varname>AssignToLoopback=
</varname></term>
1232 <para>Takes a boolean. If set to
<literal>yes
</literal>, the loopback interface
<literal>lo
</literal>
1233 is used as the underlying device of the tunnel interface. Defaults to
<literal>no
</literal>.
</para>
1237 <term><varname>AllowLocalRemote=
</varname></term>
1239 <para>Takes a boolean. When true allows tunnel traffic on
<varname>ip6tnl
</varname> devices where the remote endpoint is a local host address.
1240 When unset, the kernel's default will be used.
1245 <term><varname>FooOverUDP=
</varname></term>
1247 <para>Takes a boolean. Specifies whether
<varname>FooOverUDP=
</varname> tunnel is to be configured.
1248 Defaults to false. This takes effects only for IPIP, SIT, GRE, and GRETAP tunnels.
1249 For more detail information see
1250 <ulink url=
"https://lwn.net/Articles/614348">Foo over UDP
</ulink></para>
1254 <term><varname>FOUDestinationPort=
</varname></term>
1256 <para>This setting specifies the UDP destination port for encapsulation.
1257 This field is mandatory when
<varname>FooOverUDP=yes
</varname>, and is not set by default.
</para>
1261 <term><varname>FOUSourcePort=
</varname></term>
1263 <para>This setting specifies the UDP source port for encapsulation. Defaults to
<constant>0</constant>
1264 — that is, the source port for packets is left to the network stack to decide.
</para>
1268 <term><varname>Encapsulation=
</varname></term>
1270 <para>Accepts the same key as in the
<literal>[FooOverUDP]
</literal> section.
</para>
1274 <term><varname>IPv6RapidDeploymentPrefix=
</varname></term>
1276 <para>Reconfigure the tunnel for
<ulink url=
"https://tools.ietf.org/html/rfc5569">IPv6 Rapid
1277 Deployment
</ulink>, also known as
6rd. The value is an ISP-specific IPv6 prefix with a non-zero length. Only
1278 applicable to SIT tunnels.
</para>
1282 <term><varname>ISATAP=
</varname></term>
1284 <para>Takes a boolean. If set, configures the tunnel as Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) tunnel.
1285 Only applicable to SIT tunnels. When unset, the kernel's default will be used.
</para>
1289 <term><varname>SerializeTunneledPackets=
</varname></term>
1291 <para>Takes a boolean. If set to yes, then packets are serialized. Only applies for GRE,
1292 GRETAP, and ERSPAN tunnels. When unset, the kernel's default will be used.
1297 <term><varname>ERSPANIndex=
</varname></term>
1299 <para>Specifies the ERSPAN index field for the interface, an integer in the range
1-
1048575 associated with
1300 the ERSPAN traffic's source port and direction. This field is mandatory.
1308 <title>[FooOverUDP] Section Options
</title>
1310 <para>The
<literal>[FooOverUDP]
</literal> section only applies for
1311 netdevs of kind
<literal>fou
</literal> and accepts the
1312 following keys:
</para>
1314 <variablelist class='network-directives'
>
1316 <term><varname>Encapsulation=
</varname></term>
1318 <para>Specifies the encapsulation mechanism used to store networking packets of various protocols inside the UDP packets. Supports the following values:
1320 <literal>FooOverUDP
</literal> provides the simplest no frills model of UDP encapsulation, it simply encapsulates
1321 packets directly in the UDP payload.
1322 <literal>GenericUDPEncapsulation
</literal> is a generic and extensible encapsulation, it allows encapsulation of packets for any IP
1323 protocol and optional data as part of the encapsulation.
1324 For more detailed information see
<ulink url=
"https://lwn.net/Articles/615044">Generic UDP Encapsulation
</ulink>.
1325 Defaults to
<literal>FooOverUDP
</literal>.
1330 <term><varname>Port=
</varname></term>
1332 <para>Specifies the port number, where the IP encapsulation packets will arrive. Please take note that the packets
1333 will arrive with the encapsulation will be removed. Then they will be manually fed back into the network stack, and sent ahead
1334 for delivery to the real destination. This option is mandatory.
</para>
1338 <term><varname>PeerPort=
</varname></term>
1340 <para>Specifies the peer port number. Defaults to unset. Note that when peer port is set
<literal>Peer=
</literal> address is mandotory.
</para>
1344 <term><varname>Protocol=
</varname></term>
1346 <para>The
<varname>Protocol=
</varname> specifies the protocol number of the packets arriving
1347 at the UDP port. When
<varname>Encapsulation=FooOverUDP
</varname>, this field is mandatory
1348 and is not set by default. Takes an IP protocol name such as
<literal>gre
</literal> or
1349 <literal>ipip
</literal>, or an integer within the range
1-
255. When
1350 <varname>Encapsulation=GenericUDPEncapsulation
</varname>, this must not be specified.
</para>
1354 <term><varname>Peer=
</varname></term>
1356 <para>Configures peer IP address. Note that when peer address is set
<literal>PeerPort=
</literal> is mandotory.
</para>
1360 <term><varname>Local=
</varname></term>
1362 <para>Configures local IP address.
</para>
1369 <title>[Peer] Section Options
</title>
1371 <para>The
<literal>[Peer]
</literal> section only applies for
1372 netdevs of kind
<literal>veth
</literal> and accepts the
1373 following keys:
</para>
1375 <variablelist class='network-directives'
>
1377 <term><varname>Name=
</varname></term>
1379 <para>The interface name used when creating the netdev.
1380 This option is compulsory.
</para>
1384 <term><varname>MACAddress=
</varname></term>
1386 <para>The peer MACAddress, if not set, it is generated in
1387 the same way as the MAC address of the main
1395 <title>[VXCAN] Section Options
</title>
1397 <para>The
<literal>[VXCAN]
</literal> section only applies for
1398 netdevs of kind
<literal>vxcan
</literal> and accepts the
1399 following key:
</para>
1401 <variablelist class='network-directives'
>
1403 <term><varname>Peer=
</varname></term>
1405 <para>The peer interface name used when creating the netdev.
1406 This option is compulsory.
</para>
1413 <title>[Tun] Section Options
</title>
1415 <para>The
<literal>[Tun]
</literal> section only applies for
1416 netdevs of kind
<literal>tun
</literal>, and accepts the following
1419 <variablelist class='network-directives'
>
1421 <term><varname>MultiQueue=
</varname></term>
1422 <listitem><para>Takes a boolean. Configures whether
1423 to use multiple file descriptors (queues) to parallelize
1424 packets sending and receiving. Defaults to
1425 <literal>no
</literal>.
</para>
1429 <term><varname>PacketInfo=
</varname></term>
1430 <listitem><para>Takes a boolean. Configures whether
1431 packets should be prepended with four extra bytes (two flag
1432 bytes and two protocol bytes). If disabled, it indicates that
1433 the packets will be pure IP packets. Defaults to
1434 <literal>no
</literal>.
</para>
1438 <term><varname>VNetHeader=
</varname></term>
1439 <listitem><para>Takes a boolean. Configures
1440 IFF_VNET_HDR flag for a tun or tap device. It allows sending
1441 and receiving larger Generic Segmentation Offload (GSO)
1442 packets. This may increase throughput significantly.
1444 <literal>no
</literal>.
</para>
1448 <term><varname>User=
</varname></term>
1449 <listitem><para>User to grant access to the
1450 <filename>/dev/net/tun
</filename> device.
</para>
1454 <term><varname>Group=
</varname></term>
1455 <listitem><para>Group to grant access to the
1456 <filename>/dev/net/tun
</filename> device.
</para>
1463 <title>[Tap] Section Options
</title>
1465 <para>The
<literal>[Tap]
</literal> section only applies for
1466 netdevs of kind
<literal>tap
</literal>, and accepts the same keys
1467 as the
<literal>[Tun]
</literal> section.
</para>
1471 <title>[WireGuard] Section Options
</title>
1473 <para>The
<literal>[WireGuard]
</literal> section accepts the following
1476 <variablelist class='network-directives'
>
1478 <term><varname>PrivateKey=
</varname></term>
1480 <para>The Base64 encoded private key for the interface. It can be
1481 generated using the
<command>wg genkey
</command> command
1482 (see
<citerefentry project=
"wireguard"><refentrytitle>wg
</refentrytitle><manvolnum>8</manvolnum></citerefentry>).
1483 This option or
<varname>PrivateKeyFile=
</varname> is mandatory to use WireGuard.
1484 Note that because this information is secret, you may want to set
1485 the permissions of the .netdev file to be owned by
<literal>root:systemd-network
</literal>
1486 with a
<literal>0640</literal> file mode.
</para>
1490 <term><varname>PrivateKeyFile=
</varname></term>
1492 <para>Takes an absolute path to a file which contains the Base64 encoded private key for the interface.
1493 When this option is specified, then
<varname>PrivateKey=
</varname> is ignored.
1494 Note that the file must be readable by the user
<literal>systemd-network
</literal>, so it
1495 should be, e.g., owned by
<literal>root:systemd-network
</literal> with a
1496 <literal>0640</literal> file mode.
</para>
1500 <term><varname>ListenPort=
</varname></term>
1502 <para>Sets UDP port for listening. Takes either value between
1 and
65535
1503 or
<literal>auto
</literal>. If
<literal>auto
</literal> is specified,
1504 the port is automatically generated based on interface name.
1505 Defaults to
<literal>auto
</literal>.
</para>
1509 <term><varname>FirewallMark=
</varname></term>
1511 <para>Sets a firewall mark on outgoing WireGuard packets from this interface. Takes a number between
1 and
4294967295.
</para>
1518 <title>[WireGuardPeer] Section Options
</title>
1520 <para>The
<literal>[WireGuardPeer]
</literal> section accepts the following
1523 <variablelist class='network-directives'
>
1525 <term><varname>PublicKey=
</varname></term>
1527 <para>Sets a Base64 encoded public key calculated by
<command>wg pubkey
</command>
1528 (see
<citerefentry project=
"wireguard"><refentrytitle>wg
</refentrytitle><manvolnum>8</manvolnum></citerefentry>)
1529 from a private key, and usually transmitted out of band to the
1530 author of the configuration file. This option is mandatory for this
1535 <term><varname>PresharedKey=
</varname></term>
1537 <para>Optional preshared key for the interface. It can be generated
1538 by the
<command>wg genpsk
</command> command. This option adds an
1539 additional layer of symmetric-key cryptography to be mixed into the
1540 already existing public-key cryptography, for post-quantum
1542 Note that because this information is secret, you may want to set
1543 the permissions of the .netdev file to be owned by
<literal>root:systemd-networkd
</literal>
1544 with a
<literal>0640</literal> file mode.
</para>
1548 <term><varname>PresharedKeyFile=
</varname></term>
1550 <para>Takes an absolute path to a file which contains the Base64 encoded preshared key for the
1551 peer. When this option is specified, then
<varname>PresharedKey=
</varname> is ignored.
1552 Note that the file must be readable by the user
<literal>systemd-network
</literal>, so it
1553 should be, e.g., owned by
<literal>root:systemd-network
</literal> with a
1554 <literal>0640</literal> file mode.
</para>
1558 <term><varname>AllowedIPs=
</varname></term>
1560 <para>Sets a comma-separated list of IP (v4 or v6) addresses with CIDR masks
1561 from which this peer is allowed to send incoming traffic and to
1562 which outgoing traffic for this peer is directed. The catch-all
1563 0.0.0.0/
0 may be specified for matching all IPv4 addresses, and
1564 ::/
0 may be specified for matching all IPv6 addresses.
</para>
1568 <term><varname>Endpoint=
</varname></term>
1570 <para>Sets an endpoint IP address or hostname, followed by a colon, and then
1571 a port number. This endpoint will be updated automatically once to
1572 the most recent source IP address and port of correctly
1573 authenticated packets from the peer at configuration time.
</para>
1577 <term><varname>PersistentKeepalive=
</varname></term>
1579 <para>Sets a seconds interval, between
1 and
65535 inclusive, of how often
1580 to send an authenticated empty packet to the peer for the purpose
1581 of keeping a stateful firewall or NAT mapping valid persistently.
1582 For example, if the interface very rarely sends traffic, but it
1583 might at anytime receive traffic from a peer, and it is behind NAT,
1584 the interface might benefit from having a persistent keepalive
1585 interval of
25 seconds. If set to
0 or
"off", this option is
1586 disabled. By default or when unspecified, this option is off.
1587 Most users will not need this.
</para>
1594 <title>[Bond] Section Options
</title>
1596 <para>The
<literal>[Bond]
</literal> section accepts the following
1599 <variablelist class='network-directives'
>
1601 <term><varname>Mode=
</varname></term>
1603 <para>Specifies one of the bonding policies. The default is
1604 <literal>balance-rr
</literal> (round robin). Possible values are
1605 <literal>balance-rr
</literal>,
1606 <literal>active-backup
</literal>,
1607 <literal>balance-xor
</literal>,
1608 <literal>broadcast
</literal>,
1609 <literal>802.3ad
</literal>,
1610 <literal>balance-tlb
</literal>, and
1611 <literal>balance-alb
</literal>.
1617 <term><varname>TransmitHashPolicy=
</varname></term>
1619 <para>Selects the transmit hash policy to use for slave
1620 selection in balance-xor,
802.3ad, and tlb modes. Possible
1622 <literal>layer2
</literal>,
1623 <literal>layer3+
4</literal>,
1624 <literal>layer2+
3</literal>,
1625 <literal>encap2+
3</literal>, and
1626 <literal>encap3+
4</literal>.
1632 <term><varname>LACPTransmitRate=
</varname></term>
1634 <para>Specifies the rate with which link partner transmits
1635 Link Aggregation Control Protocol Data Unit packets in
1636 802.3ad mode. Possible values are
<literal>slow
</literal>,
1637 which requests partner to transmit LACPDUs every
30 seconds,
1638 and
<literal>fast
</literal>, which requests partner to
1639 transmit LACPDUs every second. The default value is
1640 <literal>slow
</literal>.
</para>
1645 <term><varname>MIIMonitorSec=
</varname></term>
1647 <para>Specifies the frequency that Media Independent
1648 Interface link monitoring will occur. A value of zero
1649 disables MII link monitoring. This value is rounded down to
1650 the nearest millisecond. The default value is
0.
</para>
1655 <term><varname>UpDelaySec=
</varname></term>
1657 <para>Specifies the delay before a link is enabled after a
1658 link up status has been detected. This value is rounded down
1659 to a multiple of MIIMonitorSec. The default value is
1665 <term><varname>DownDelaySec=
</varname></term>
1667 <para>Specifies the delay before a link is disabled after a
1668 link down status has been detected. This value is rounded
1669 down to a multiple of MIIMonitorSec. The default value is
1675 <term><varname>LearnPacketIntervalSec=
</varname></term>
1677 <para>Specifies the number of seconds between instances where the bonding
1678 driver sends learning packets to each slave peer switch.
1679 The valid range is
1–
0x7fffffff; the default value is
1. This option
1680 has an effect only for the balance-tlb and balance-alb modes.
</para>
1685 <term><varname>AdSelect=
</varname></term>
1687 <para>Specifies the
802.3ad aggregation selection logic to use. Possible values are
1688 <literal>stable
</literal>,
1689 <literal>bandwidth
</literal> and
1690 <literal>count
</literal>.
1696 <term><varname>AdActorSystemPriority=
</varname></term>
1698 <para>Specifies the
802.3ad actor system priority. Ranges [
1-
65535].
</para>
1703 <term><varname>AdUserPortKey=
</varname></term>
1705 <para>Specifies the
802.3ad user defined portion of the port key. Ranges [
0-
1023].
</para>
1710 <term><varname>AdActorSystem=
</varname></term>
1712 <para>Specifies the
802.3ad system mac address. This can not be either NULL or Multicast.
</para>
1717 <term><varname>FailOverMACPolicy=
</varname></term>
1719 <para>Specifies whether the active-backup mode should set all slaves to
1720 the same MAC address at the time of enslavement or, when enabled, to perform special handling of the
1721 bond's MAC address in accordance with the selected policy. The default policy is none.
1723 <literal>none
</literal>,
1724 <literal>active
</literal> and
1725 <literal>follow
</literal>.
1731 <term><varname>ARPValidate=
</varname></term>
1733 <para>Specifies whether or not ARP probes and replies should be
1734 validated in any mode that supports ARP monitoring, or whether
1735 non-ARP traffic should be filtered (disregarded) for link
1736 monitoring purposes. Possible values are
1737 <literal>none
</literal>,
1738 <literal>active
</literal>,
1739 <literal>backup
</literal> and
1740 <literal>all
</literal>.
1746 <term><varname>ARPIntervalSec=
</varname></term>
1748 <para>Specifies the ARP link monitoring frequency. A value of
0 disables ARP monitoring. The
1749 default value is
0, and the default unit seconds.
1755 <term><varname>ARPIPTargets=
</varname></term>
1757 <para>Specifies the IP addresses to use as ARP monitoring peers when
1758 ARPIntervalSec is greater than
0. These are the targets of the ARP request
1759 sent to determine the health of the link to the targets.
1760 Specify these values in IPv4 dotted decimal format. At least one IP
1761 address must be given for ARP monitoring to function. The
1762 maximum number of targets that can be specified is
16. The
1763 default value is no IP addresses.
1769 <term><varname>ARPAllTargets=
</varname></term>
1771 <para>Specifies the quantity of ARPIPTargets that must be reachable
1772 in order for the ARP monitor to consider a slave as being up.
1773 This option affects only active-backup mode for slaves with
1774 ARPValidate enabled. Possible values are
1775 <literal>any
</literal> and
1776 <literal>all
</literal>.
1782 <term><varname>PrimaryReselectPolicy=
</varname></term>
1784 <para>Specifies the reselection policy for the primary slave. This
1785 affects how the primary slave is chosen to become the active slave
1786 when failure of the active slave or recovery of the primary slave
1787 occurs. This option is designed to prevent flip-flopping between
1788 the primary slave and other slaves. Possible values are
1789 <literal>always
</literal>,
1790 <literal>better
</literal> and
1791 <literal>failure
</literal>.
1797 <term><varname>ResendIGMP=
</varname></term>
1799 <para>Specifies the number of IGMP membership reports to be issued after
1800 a failover event. One membership report is issued immediately after
1801 the failover, subsequent packets are sent in each
200ms interval.
1802 The valid range is
0–
255. Defaults to
1. A value of
0
1803 prevents the IGMP membership report from being issued in response
1804 to the failover event.
1810 <term><varname>PacketsPerSlave=
</varname></term>
1812 <para>Specify the number of packets to transmit through a slave before
1813 moving to the next one. When set to
0, then a slave is chosen at
1814 random. The valid range is
0–
65535. Defaults to
1. This option
1815 only has effect when in balance-rr mode.
1821 <term><varname>GratuitousARP=
</varname></term>
1823 <para>Specify the number of peer notifications (gratuitous ARPs and
1824 unsolicited IPv6 Neighbor Advertisements) to be issued after a
1825 failover event. As soon as the link is up on the new slave,
1826 a peer notification is sent on the bonding device and each
1827 VLAN sub-device. This is repeated at each link monitor interval
1828 (ARPIntervalSec or MIIMonitorSec, whichever is active) if the number is
1829 greater than
1. The valid range is
0–
255. The default value is
1.
1830 These options affect only the active-backup mode.
1836 <term><varname>AllSlavesActive=
</varname></term>
1838 <para>Takes a boolean. Specifies that duplicate frames (received on inactive ports)
1839 should be dropped when false, or delivered when true. Normally, bonding will drop
1840 duplicate frames (received on inactive ports), which is desirable for
1841 most users. But there are some times it is nice to allow duplicate
1842 frames to be delivered. The default value is false (drop duplicate frames
1843 received on inactive ports).
1849 <term><varname>DynamicTransmitLoadBalancing=
</varname></term>
1851 <para>Takes a boolean. Specifies if dynamic shuffling of flows is enabled. Applies only
1852 for balance-tlb mode. Defaults to unset.
1858 <term><varname>MinLinks=
</varname></term>
1860 <para>Specifies the minimum number of links that must be active before
1861 asserting carrier. The default value is
0.
1867 <para>For more detail information see
1868 <ulink url=
"https://www.kernel.org/doc/Documentation/networking/bonding.txt">
1869 Linux Ethernet Bonding Driver HOWTO
</ulink></para>
1873 <title>[Xfrm] Section Options
</title>
1875 <para>The
<literal>[Xfrm]
</literal> section accepts the following
1878 <variablelist class='network-directives'
>
1880 <term><varname>InterfaceId=
</varname></term>
1882 <para>Sets the ID/key of the xfrm interface which needs to be associated with a SA/policy.
1883 Can be decimal or hexadecimal, valid range is
0-
0xffffffff, defaults to
0.
</para>
1887 <term><varname>Independent=
</varname></term>
1889 <para>Takes a boolean. If set to
<literal>no
</literal>, the xfrm interface should have an
1890 underlying device which can be used for hardware offloading. Defaults to
<literal>no
</literal>.
1891 See
<citerefentry><refentrytitle>systemd.network
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
1892 for how to configure the underlying device.
</para>
1897 <para>For more detail information see
1898 <ulink url=
"https://lwn.net/Articles/757391">
1899 Virtual xfrm interfaces
</ulink></para>
1903 <title>[VRF] Section Options
</title>
1904 <para>The
<literal>[VRF]
</literal> section only applies for
1905 netdevs of kind
<literal>vrf
</literal> and accepts the
1906 following key:
</para>
1908 <variablelist class='network-directives'
>
1910 <term><varname>Table=
</varname></term>
1912 <para>The numeric routing table identifier. This option is compulsory.
</para>
1919 <title>Examples
</title>
1921 <title>/etc/systemd/network/
25-bridge.netdev
</title>
1923 <programlisting>[NetDev]
1925 Kind=bridge
</programlisting>
1929 <title>/etc/systemd/network/
25-vlan1.netdev
</title>
1931 <programlisting>[Match]
1939 Id=
1</programlisting>
1942 <title>/etc/systemd/network/
25-ipip.netdev
</title>
1943 <programlisting>[NetDev]
1949 Local=
192.168.223.238
1950 Remote=
192.169.224.239
1951 TTL=
64</programlisting>
1954 <title>/etc/systemd/network/
1-fou-tunnel.netdev
</title>
1955 <programlisting>[NetDev]
1965 <title>/etc/systemd/network/
25-fou-ipip.netdev
</title>
1966 <programlisting>[NetDev]
1973 Remote=
10.65.208.211
1975 FOUDestinationPort=
5555
1979 <title>/etc/systemd/network/
25-tap.netdev
</title>
1980 <programlisting>[NetDev]
1986 PacketInfo=yes
</programlisting> </example>
1989 <title>/etc/systemd/network/
25-sit.netdev
</title>
1990 <programlisting>[NetDev]
1997 Remote=
10.65.223.239</programlisting>
2001 <title>/etc/systemd/network/
25-
6rd.netdev
</title>
2002 <programlisting>[NetDev]
2009 IPv6RapidDeploymentPrefix=
2602::/
24</programlisting>
2013 <title>/etc/systemd/network/
25-gre.netdev
</title>
2014 <programlisting>[NetDev]
2021 Remote=
10.65.223.239</programlisting>
2025 <title>/etc/systemd/network/
25-ip6gre.netdev
</title>
2026 <programlisting>[NetDev]
2031 Key=
123</programlisting>
2035 <title>/etc/systemd/network/
25-vti.netdev
</title>
2037 <programlisting>[NetDev]
2044 Remote=
10.65.223.239</programlisting>
2048 <title>/etc/systemd/network/
25-veth.netdev
</title>
2049 <programlisting>[NetDev]
2054 Name=veth-peer
</programlisting>
2058 <title>/etc/systemd/network/
25-bond.netdev
</title>
2059 <programlisting>[NetDev]
2065 TransmitHashPolicy=layer3+
4
2067 LACPTransmitRate=fast
2072 <title>/etc/systemd/network/
25-dummy.netdev
</title>
2073 <programlisting>[NetDev]
2076 MACAddress=
12:
34:
56:
78:
9a:bc
</programlisting>
2079 <title>/etc/systemd/network/
25-vrf.netdev
</title>
2080 <para>Create a VRF interface with table
42.
</para>
2081 <programlisting>[NetDev]
2086 Table=
42</programlisting>
2090 <title>/etc/systemd/network/
25-macvtap.netdev
</title>
2091 <para>Create a MacVTap device.
</para>
2092 <programlisting>[NetDev]
2098 <title>/etc/systemd/network/
25-wireguard.netdev
</title>
2099 <programlisting>[NetDev]
2104 PrivateKey=EEGlnEPYJV//kbvvIqxKkQwOiS+UENyPncC4bF46ong=
2108 PublicKey=RDf+LSpeEre7YEIKaxg+wbpsNV7du+ktR99uBEtIiCA=
2109 AllowedIPs=fd31:bf08:
57cb::/
48,
192.168.26.0/
24
2110 Endpoint=wireguard.example.com:
51820</programlisting>
2114 <title>/etc/systemd/network/
27-xfrm.netdev
</title>
2115 <programlisting>[NetDev]
2120 Independent=yes
</programlisting>
2125 <title>See Also
</title>
2127 <citerefentry><refentrytitle>systemd
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
2128 <citerefentry><refentrytitle>systemd-networkd
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
2129 <citerefentry><refentrytitle>systemd.link
</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
2130 <citerefentry><refentrytitle>systemd.network
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
projects / thirdparty / systemd.git / blob