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+ -->
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>A plain ini-style text file that encodes configuration about a virtual network device, used by
31 <citerefentry><refentrytitle>systemd-networkd
</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
32 See
<citerefentry><refentrytitle>systemd.syntax
</refentrytitle><manvolnum>7</manvolnum></citerefentry>
33 for a general description of the syntax.
</para>
35 <para>The main Virtual Network Device file must have the extension
<filename>.netdev
</filename>;
36 other extensions are ignored. Virtual network devices are created as soon as networkd is
37 started. If a netdev with the specified name already exists, networkd will use that as-is rather
38 than create its own. Note that the settings of the pre-existing netdev will not be changed by
41 <para>The
<filename>.netdev
</filename> files are read from the files located in the system
42 network directory
<filename>/usr/lib/systemd/network
</filename>, the volatile runtime network
43 directory
<filename>/run/systemd/network
</filename> and the local administration network
44 directory
<filename>/etc/systemd/network
</filename>. All configuration files are collectively
45 sorted and processed in lexical order, regardless of the directories in which they live.
46 However, files with identical filenames replace each other. Files in
<filename>/etc
</filename>
47 have the highest priority, files in
<filename>/run
</filename> take precedence over files with
48 the same name in
<filename>/usr/lib
</filename>. This can be used to override a system-supplied
49 configuration file with a local file if needed. As a special case, an empty file (file size
0)
50 or symlink with the same name pointing to
<filename>/dev/null
</filename> disables the
51 configuration file entirely (it is
"masked").
</para>
53 <para>Along with the netdev file
<filename>foo.netdev
</filename>, a
"drop-in" directory
54 <filename>foo.netdev.d/
</filename> may exist. All files with the suffix
<literal>.conf
</literal>
55 from this directory will be parsed after the file itself is parsed. This is useful to alter or
56 add configuration settings, without having to modify the main configuration file. Each drop-in
57 file must have appropriate section headers.
</para>
59 <para>In addition to
<filename>/etc/systemd/network
</filename>, drop-in
<literal>.d
</literal>
60 directories can be placed in
<filename>/usr/lib/systemd/network
</filename> or
61 <filename>/run/systemd/network
</filename> directories. Drop-in files in
62 <filename>/etc
</filename> take precedence over those in
<filename>/run
</filename> which in turn
63 take precedence over those in
<filename>/usr/lib
</filename>. Drop-in files under any of these
64 directories take precedence over the main netdev file wherever located. (Of course, since
65 <filename>/run
</filename> is temporary and
<filename>/usr/lib
</filename> is for vendors, it is
66 unlikely drop-ins should be used in either of those places.)
</para>
70 <title>Supported netdev kinds
</title>
72 <para>The following kinds of virtual network devices may be
73 configured in
<filename>.netdev
</filename> files:
</para>
76 <title>Supported kinds of virtual network devices
</title>
79 <colspec colname='kind'
/>
80 <colspec colname='explanation'
/>
83 <entry>Description
</entry>
86 <row><entry><varname>bond
</varname></entry>
87 <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>
89 <row><entry><varname>bridge
</varname></entry>
90 <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>
92 <row><entry><varname>dummy
</varname></entry>
93 <entry>A dummy device drops all packets sent to it.
</entry></row>
95 <row><entry><varname>gre
</varname></entry>
96 <entry>A Level
3 GRE tunnel over IPv4. See
<ulink url=
"https://tools.ietf.org/html/rfc2784">RFC
2784</ulink> for details.
</entry></row>
98 <row><entry><varname>gretap
</varname></entry>
99 <entry>A Level
2 GRE tunnel over IPv4.
</entry></row>
101 <row><entry><varname>erspan
</varname></entry>
102 <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>
104 <row><entry><varname>ip6gre
</varname></entry>
105 <entry>A Level
3 GRE tunnel over IPv6.
</entry></row>
107 <row><entry><varname>ip6tnl
</varname></entry>
108 <entry>An IPv4 or IPv6 tunnel over IPv6
</entry></row>
110 <row><entry><varname>ip6gretap
</varname></entry>
111 <entry>A Level
2 GRE tunnel over IPv6.
</entry></row>
113 <row><entry><varname>ipip
</varname></entry>
114 <entry>An IPv4 over IPv4 tunnel.
</entry></row>
116 <row><entry><varname>ipvlan
</varname></entry>
117 <entry>An IPVLAN device is a stacked device which receives packets from its underlying device based on IP address filtering.
</entry></row>
119 <row><entry><varname>ipvtap
</varname></entry>
120 <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>
122 <row><entry><varname>macvlan
</varname></entry>
123 <entry>A macvlan device is a stacked device which receives packets from its underlying device based on MAC address filtering.
</entry></row>
125 <row><entry><varname>macvtap
</varname></entry>
126 <entry>A macvtap device is a stacked device which receives packets from its underlying device based on MAC address filtering.
</entry></row>
128 <row><entry><varname>sit
</varname></entry>
129 <entry>An IPv6 over IPv4 tunnel.
</entry></row>
131 <row><entry><varname>tap
</varname></entry>
132 <entry>A persistent Level
2 tunnel between a network device and a device node.
</entry></row>
134 <row><entry><varname>tun
</varname></entry>
135 <entry>A persistent Level
3 tunnel between a network device and a device node.
</entry></row>
137 <row><entry><varname>veth
</varname></entry>
138 <entry>An Ethernet tunnel between a pair of network devices.
</entry></row>
140 <row><entry><varname>vlan
</varname></entry>
141 <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>
143 <row><entry><varname>vti
</varname></entry>
144 <entry>An IPv4 over IPSec tunnel.
</entry></row>
146 <row><entry><varname>vti6
</varname></entry>
147 <entry>An IPv6 over IPSec tunnel.
</entry></row>
149 <row><entry><varname>vxlan
</varname></entry>
150 <entry>A virtual extensible LAN (vxlan), for connecting Cloud computing deployments.
</entry></row>
152 <row><entry><varname>geneve
</varname></entry>
153 <entry>A GEneric NEtwork Virtualization Encapsulation (GENEVE) netdev driver.
</entry></row>
155 <row><entry><varname>l2tp
</varname></entry>
156 <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>
158 <row><entry><varname>macsec
</varname></entry>
159 <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>
161 <row><entry><varname>vrf
</varname></entry>
162 <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>
164 <row><entry><varname>vcan
</varname></entry>
165 <entry>The virtual CAN driver (vcan). Similar to the network loopback devices, vcan offers a virtual local CAN interface.
</entry></row>
167 <row><entry><varname>vxcan
</varname></entry>
168 <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.
171 <row><entry><varname>wireguard
</varname></entry>
172 <entry>WireGuard Secure Network Tunnel.
</entry></row>
174 <row><entry><varname>nlmon
</varname></entry>
175 <entry>A Netlink monitor device. Use an nlmon device when you want to monitor system Netlink messages.
</entry></row>
177 <row><entry><varname>fou
</varname></entry>
178 <entry>Foo-over-UDP tunneling.
</entry></row>
180 <row><entry><varname>xfrm
</varname></entry>
181 <entry>A virtual tunnel interface like vti/vti6 but with several advantages.
</entry></row>
183 <row><entry><varname>ifb
</varname></entry>
184 <entry> The Intermediate Functional Block (ifb) pseudo network interface acts as a QoS concentrator for multiple different sources of traffic.
</entry></row>
193 <title>[Match] Section Options
</title>
195 <para>A virtual network device is only created if the
196 [Match] section matches the current
197 environment, or if the section is empty. The following keys are
200 <variablelist class='network-directives'
>
202 <term><varname>Host=
</varname></term>
204 <para>Matches against the hostname or machine ID of the host. See
205 <literal>ConditionHost=
</literal> in
206 <citerefentry><refentrytitle>systemd.unit
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
207 for details. When prefixed with an exclamation mark (
<literal>!
</literal>), the result is negated.
208 If an empty string is assigned, then previously assigned value is cleared.
213 <term><varname>Virtualization=
</varname></term>
215 <para>Checks whether the system is executed in a virtualized environment and optionally test
216 whether it is a specific implementation. See
<literal>ConditionVirtualization=
</literal> in
217 <citerefentry><refentrytitle>systemd.unit
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
218 for details. When prefixed with an exclamation mark (
<literal>!
</literal>), the result is negated.
219 If an empty string is assigned, then previously assigned value is cleared.
224 <term><varname>KernelCommandLine=
</varname></term>
226 <para>Checks whether a specific kernel command line option is set. See
227 <literal>ConditionKernelCommandLine=
</literal> in
228 <citerefentry><refentrytitle>systemd.unit
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
229 for details. When prefixed with an exclamation mark (
<literal>!
</literal>), the result is negated.
230 If an empty string is assigned, then previously assigned value is cleared.
235 <term><varname>KernelVersion=
</varname></term>
237 <para>Checks whether the kernel version (as reported by
<command>uname -r
</command>) matches a
238 certain expression. See
<literal>ConditionKernelVersion=
</literal> in
239 <citerefentry><refentrytitle>systemd.unit
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
240 for details. When prefixed with an exclamation mark (
<literal>!
</literal>), the result is negated.
241 If an empty string is assigned, then previously assigned value is cleared.
246 <term><varname>Architecture=
</varname></term>
248 <para>Checks whether the system is running on a specific architecture. See
249 <literal>ConditionArchitecture=
</literal> in
250 <citerefentry><refentrytitle>systemd.unit
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
251 for details. When prefixed with an exclamation mark (
<literal>!
</literal>), the result is negated.
252 If an empty string is assigned, then previously assigned value is cleared.
260 <title>[NetDev] Section Options
</title>
262 <para>The [NetDev] section accepts the
263 following keys:
</para>
265 <variablelist class='network-directives'
>
267 <term><varname>Description=
</varname></term>
269 <para>A free-form description of the netdev.
</para>
273 <term><varname>Name=
</varname></term>
275 <para>The interface name used when creating the netdev.
276 This setting is compulsory.
</para>
280 <term><varname>Kind=
</varname></term>
282 <para>The netdev kind. This setting is compulsory. See the
283 <literal>Supported netdev kinds
</literal> section for the
288 <term><varname>MTUBytes=
</varname></term>
290 <para>The maximum transmission unit in bytes to set for the device. The usual suffixes K, M, G
291 are supported and are understood to the base of
1024. For
<literal>tun
</literal> or
292 <literal>tap
</literal> devices,
<varname>MTUBytes=
</varname> setting is not currently supported in
293 [NetDev] section. Please specify it in [Link] section of
295 <citerefentry><refentrytitle>systemd.network
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
300 <term><varname>MACAddress=
</varname></term>
302 <para>The MAC address to use for the device. For
<literal>tun
</literal> or
<literal>tap
</literal>
303 devices, setting
<varname>MACAddress=
</varname> in the [NetDev] section is not
304 supported. Please specify it in [Link] section of the corresponding
305 <citerefentry><refentrytitle>systemd.network
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
306 file. If this option is not set,
<literal>vlan
</literal> devices inherit the MAC address of the
307 physical interface. For other kind of netdevs, if this option is not set, then MAC address is
308 generated based on the interface name and the
309 <citerefentry><refentrytitle>machine-id
</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
317 <title>[Bridge] Section Options
</title>
319 <para>The [Bridge] section only applies for
320 netdevs of kind
<literal>bridge
</literal>, and accepts the
321 following keys:
</para>
323 <variablelist class='network-directives'
>
325 <term><varname>HelloTimeSec=
</varname></term>
327 <para>HelloTimeSec specifies the number of seconds between two hello packets
328 sent out by the root bridge and the designated bridges. Hello packets are
329 used to communicate information about the topology throughout the entire
330 bridged local area network.
</para>
334 <term><varname>MaxAgeSec=
</varname></term>
336 <para>MaxAgeSec specifies the number of seconds of maximum message age.
337 If the last seen (received) hello packet is more than this number of
338 seconds old, the bridge in question will start the takeover procedure
339 in attempt to become the Root Bridge itself.
</para>
343 <term><varname>ForwardDelaySec=
</varname></term>
345 <para>ForwardDelaySec specifies the number of seconds spent in each
346 of the Listening and Learning states before the Forwarding state is entered.
</para>
350 <term><varname>AgeingTimeSec=
</varname></term>
352 <para>This specifies the number of seconds a MAC Address will be kept in
353 the forwarding database after having a packet received from this MAC Address.
</para>
357 <term><varname>Priority=
</varname></term>
359 <para>The priority of the bridge. An integer between
0 and
65535. A lower value
360 means higher priority. The bridge having the lowest priority will be elected as root bridge.
</para>
364 <term><varname>GroupForwardMask=
</varname></term>
366 <para>A
16-bit bitmask represented as an integer which allows forwarding of link
367 local frames with
802.1D reserved addresses (
01:
80:C2:
00:
00:
0X). A logical AND
368 is performed between the specified bitmask and the exponentiation of
2^X, the
369 lower nibble of the last octet of the MAC address. For example, a value of
8
370 would allow forwarding of frames addressed to
01:
80:C2:
00:
00:
03 (
802.1X PAE).
</para>
374 <term><varname>DefaultPVID=
</varname></term>
376 <para>This specifies the default port VLAN ID of a newly attached bridge port.
377 Set this to an integer in the range
1–
4094 or
<literal>none
</literal> to disable the PVID.
</para>
381 <term><varname>MulticastQuerier=
</varname></term>
383 <para>Takes a boolean. This setting controls the IFLA_BR_MCAST_QUERIER option in the kernel.
384 If enabled, the kernel will send general ICMP queries from a zero source address.
385 This feature should allow faster convergence on startup, but it causes some
386 multicast-aware switches to misbehave and disrupt forwarding of multicast packets.
387 When unset, the kernel's default will be used.
392 <term><varname>MulticastSnooping=
</varname></term>
394 <para>Takes a boolean. This setting controls the IFLA_BR_MCAST_SNOOPING option in the kernel.
395 If enabled, IGMP snooping monitors the Internet Group Management Protocol (IGMP) traffic
396 between hosts and multicast routers. When unset, the kernel's default will be used.
401 <term><varname>VLANFiltering=
</varname></term>
403 <para>Takes a boolean. This setting controls the IFLA_BR_VLAN_FILTERING option in the kernel.
404 If enabled, the bridge will be started in VLAN-filtering mode. When unset, the kernel's default will be used.
409 <term><varname>VLANProtocol=
</varname></term>
411 <para>Allows setting the protocol used for VLAN filtering. Takes
412 <option>802.1q
</option> or,
413 <option>802.1ad
</option>, and defaults to unset and kernel's default is used.
418 <term><varname>STP=
</varname></term>
420 <para>Takes a boolean. This enables the bridge's Spanning Tree Protocol (STP).
421 When unset, the kernel's default will be used.
426 <term><varname>MulticastIGMPVersion=
</varname></term>
428 <para>Allows changing bridge's multicast Internet Group Management Protocol (IGMP) version.
429 Takes an integer
2 or
3. When unset, the kernel's default will be used.
437 <title>[VLAN] Section Options
</title>
439 <para>The [VLAN] section only applies for
440 netdevs of kind
<literal>vlan
</literal>, and accepts the
441 following key:
</para>
443 <variablelist class='network-directives'
>
445 <term><varname>Id=
</varname></term>
447 <para>The VLAN ID to use. An integer in the range
0–
4094.
448 This setting is compulsory.
</para>
452 <term><varname>GVRP=
</varname></term>
454 <para>Takes a boolean. The Generic VLAN Registration Protocol (GVRP) is a protocol that
455 allows automatic learning of VLANs on a network.
456 When unset, the kernel's default will be used.
461 <term><varname>MVRP=
</varname></term>
463 <para>Takes a boolean. Multiple VLAN Registration Protocol (MVRP) formerly known as GARP VLAN
464 Registration Protocol (GVRP) is a standards-based Layer
2 network protocol,
465 for automatic configuration of VLAN information on switches. It was defined
466 in the
802.1ak amendment to
802.1Q-
2005. When unset, the kernel's default will be used.
471 <term><varname>LooseBinding=
</varname></term>
473 <para>Takes a boolean. The VLAN loose binding mode, in which only the operational state is passed
474 from the parent to the associated VLANs, but the VLAN device state is not changed.
475 When unset, the kernel's default will be used.
</para>
479 <term><varname>ReorderHeader=
</varname></term>
481 <para>Takes a boolean. When enabled, the VLAN reorder header is used and VLAN interfaces behave
482 like physical interfaces. When unset, the kernel's default will be used.
</para>
489 <title>[MACVLAN] Section Options
</title>
491 <para>The [MACVLAN] section only applies for
492 netdevs of kind
<literal>macvlan
</literal>, and accepts the
493 following key:
</para>
495 <variablelist class='network-directives'
>
497 <term><varname>Mode=
</varname></term>
499 <para>The MACVLAN mode to use. The supported options are
500 <literal>private
</literal>,
501 <literal>vepa
</literal>,
502 <literal>bridge
</literal>,
503 <literal>passthru
</literal>, and
504 <literal>source
</literal>.
509 <term><varname>SourceMACAddress=
</varname></term>
511 <para>A whitespace-separated list of remote hardware addresses allowed on the MACVLAN. This
512 option only has an effect in source mode. Use full colon-, hyphen- or dot-delimited
513 hexadecimal. This option may appear more than once, in which case the lists are merged. If
514 the empty string is assigned to this option, the list of hardware addresses defined prior
515 to this is reset. Defaults to unset.
</para>
522 <title>[MACVTAP] Section Options
</title>
524 <para>The [MACVTAP] section applies for
525 netdevs of kind
<literal>macvtap
</literal> and accepts the
526 same key as [MACVLAN].
</para>
530 <title>[IPVLAN] Section Options
</title>
532 <para>The [IPVLAN] section only applies for
533 netdevs of kind
<literal>ipvlan
</literal>, and accepts the
534 following key:
</para>
536 <variablelist class='network-directives'
>
538 <term><varname>Mode=
</varname></term>
540 <para>The IPVLAN mode to use. The supported options are
541 <literal>L2
</literal>,
<literal>L3
</literal> and
<literal>L3S
</literal>.
546 <term><varname>Flags=
</varname></term>
548 <para>The IPVLAN flags to use. The supported options are
549 <literal>bridge
</literal>,
<literal>private
</literal> and
<literal>vepa
</literal>.
557 <title>[IPVTAP] Section Options
</title>
559 <para>The [IPVTAP] section only applies for
560 netdevs of kind
<literal>ipvtap
</literal> and accepts the
561 same key as [IPVLAN].
</para>
565 <title>[VXLAN] Section Options
</title>
567 <para>The [VXLAN] section only applies for
568 netdevs of kind
<literal>vxlan
</literal>, and accepts the
569 following keys:
</para>
571 <variablelist class='network-directives'
>
573 <term><varname>VNI=
</varname></term>
575 <para>The VXLAN Network Identifier (or VXLAN Segment ID). Takes a number in the range
1-
16777215.
</para>
579 <term><varname>Remote=
</varname></term>
581 <para>Configures destination IP address.
</para>
585 <term><varname>Local=
</varname></term>
587 <para>Configures local IP address.
</para>
591 <term><varname>Group=
</varname></term>
593 <para>Configures VXLAN multicast group IP address. All members of a VXLAN must use the same
594 multicast group address.
</para>
598 <term><varname>TOS=
</varname></term>
600 <para>The Type Of Service byte value for a vxlan interface.
</para>
604 <term><varname>TTL=
</varname></term>
606 <para>A fixed Time To Live N on Virtual eXtensible Local Area Network packets.
607 Takes
<literal>inherit
</literal> or a number in the range
0–
255.
0 is a special
608 value meaning inherit the inner protocol's TTL value.
<literal>inherit
</literal>
609 means that it will inherit the outer protocol's TTL value.
</para>
613 <term><varname>MacLearning=
</varname></term>
615 <para>Takes a boolean. When true, enables dynamic MAC learning
616 to discover remote MAC addresses.
</para>
620 <term><varname>FDBAgeingSec=
</varname></term>
622 <para>The lifetime of Forwarding Database entry learnt by
623 the kernel, in seconds.
</para>
627 <term><varname>MaximumFDBEntries=
</varname></term>
629 <para>Configures maximum number of FDB entries.
</para>
633 <term><varname>ReduceARPProxy=
</varname></term>
635 <para>Takes a boolean. When true, bridge-connected VXLAN tunnel
636 endpoint answers ARP requests from the local bridge on behalf
637 of remote Distributed Overlay Virtual Ethernet
638 <ulink url=
"https://en.wikipedia.org/wiki/Distributed_Overlay_Virtual_Ethernet">
639 (DVOE)
</ulink> clients. Defaults to false.
</para>
643 <term><varname>L2MissNotification=
</varname></term>
645 <para>Takes a boolean. When true, enables netlink LLADDR miss
646 notifications.
</para>
650 <term><varname>L3MissNotification=
</varname></term>
652 <para>Takes a boolean. When true, enables netlink IP address miss notifications.
</para>
656 <term><varname>RouteShortCircuit=
</varname></term>
658 <para>Takes a boolean. When true, route short circuiting is turned
663 <term><varname>UDPChecksum=
</varname></term>
665 <para>Takes a boolean. When true, transmitting UDP checksums when doing VXLAN/IPv4 is turned on.
</para>
669 <term><varname>UDP6ZeroChecksumTx=
</varname></term>
671 <para>Takes a boolean. When true, sending zero checksums in VXLAN/IPv6 is turned on.
</para>
675 <term><varname>UDP6ZeroChecksumRx=
</varname></term>
677 <para>Takes a boolean. When true, receiving zero checksums in VXLAN/IPv6 is turned on.
</para>
681 <term><varname>RemoteChecksumTx=
</varname></term>
683 <para>Takes a boolean. When true, remote transmit checksum offload of VXLAN is turned on.
</para>
687 <term><varname>RemoteChecksumRx=
</varname></term>
689 <para>Takes a boolean. When true, remote receive checksum offload in VXLAN is turned on.
</para>
693 <term><varname>GroupPolicyExtension=
</varname></term>
695 <para>Takes a boolean. When true, it enables Group Policy VXLAN extension security label mechanism
696 across network peers based on VXLAN. For details about the Group Policy VXLAN, see the
697 <ulink url=
"https://tools.ietf.org/html/draft-smith-vxlan-group-policy">
698 VXLAN Group Policy
</ulink> document. Defaults to false.
</para>
702 <term><varname>GenericProtocolExtension=
</varname></term>
704 <para>Takes a boolean. When true, Generic Protocol Extension extends the existing VXLAN protocol
705 to provide protocol typing, OAM, and versioning capabilities. For details about the VXLAN GPE
706 Header, see the
<ulink url=
"https://tools.ietf.org/html/draft-ietf-nvo3-vxlan-gpe-07">
707 Generic Protocol Extension for VXLAN
</ulink> document. If destination port is not specified and
708 Generic Protocol Extension is set then default port of
4790 is used. Defaults to false.
</para>
712 <term><varname>DestinationPort=
</varname></term>
714 <para>Configures the default destination UDP port on a per-device basis.
715 If destination port is not specified then Linux kernel default will be used.
716 Set destination port
4789 to get the IANA assigned value. If not set or if the
717 destination port is assigned the empty string the default port of
4789 is used.
</para>
721 <term><varname>PortRange=
</varname></term>
723 <para>Configures VXLAN port range. VXLAN bases source
724 UDP port based on flow to help the receiver to be able
725 to load balance based on outer header flow. It
726 restricts the port range to the normal UDP local
727 ports, and allows overriding via configuration.
</para>
731 <term><varname>FlowLabel=
</varname></term>
733 <para>Specifies the flow label to use in outgoing packets.
734 The valid range is
0-
1048575.
739 <term><varname>IPDoNotFragment=
</varname></term>
741 <para>Allows setting the IPv4 Do not Fragment (DF) bit in outgoing packets, or to inherit its
742 value from the IPv4 inner header. Takes a boolean value, or
<literal>inherit
</literal>. Set
743 to
<literal>inherit
</literal> if the encapsulated protocol is IPv6. When unset, the kernel's
744 default will be used.
</para>
751 <title>[GENEVE] Section Options
</title>
753 <para>The [GENEVE] section only applies for
754 netdevs of kind
<literal>geneve
</literal>, and accepts the
755 following keys:
</para>
757 <variablelist class='network-directives'
>
759 <term><varname>Id=
</varname></term>
761 <para>Specifies the Virtual Network Identifier (VNI) to use. Ranges [
0-
16777215]. This field is mandatory.
</para>
765 <term><varname>Remote=
</varname></term>
767 <para>Specifies the unicast destination IP address to use in outgoing packets.
</para>
771 <term><varname>TOS=
</varname></term>
773 <para>Specifies the TOS value to use in outgoing packets. Ranges [
1-
255].
</para>
777 <term><varname>TTL=
</varname></term>
779 <para>Accepts the same values as in the [VXLAN] section, except that when unset
780 or set to
0, the kernel's default will be used, meaning that packet TTL will be set from
781 <filename>/proc/sys/net/ipv4/ip_default_ttl
</filename>.
</para>
785 <term><varname>UDPChecksum=
</varname></term>
787 <para>Takes a boolean. When true, specifies that UDP checksum is calculated for transmitted packets
792 <term><varname>UDP6ZeroChecksumTx=
</varname></term>
794 <para>Takes a boolean. When true, skip UDP checksum calculation for transmitted packets over IPv6.
</para>
798 <term><varname>UDP6ZeroChecksumRx=
</varname></term>
800 <para>Takes a boolean. When true, allows incoming UDP packets over IPv6 with zero checksum field.
</para>
804 <term><varname>DestinationPort=
</varname></term>
806 <para>Specifies destination port. Defaults to
6081. If not set or assigned the empty string, the default
807 port of
6081 is used.
</para>
811 <term><varname>FlowLabel=
</varname></term>
813 <para>Specifies the flow label to use in outgoing packets.
</para>
817 <term><varname>IPDoNotFragment=
</varname></term>
819 <para>Accepts the same key in [VXLAN] section.
</para>
826 <title>[L2TP] Section Options
</title>
828 <para>The [L2TP] section only applies for
829 netdevs of kind
<literal>l2tp
</literal>, and accepts the
830 following keys:
</para>
832 <variablelist class='network-directives'
>
834 <term><varname>TunnelId=
</varname></term>
836 <para>Specifies the tunnel identifier. Takes an number in the range
1–
4294967295. The value used
837 must match the
<literal>PeerTunnelId=
</literal> value being used at the peer. This setting is
842 <term><varname>PeerTunnelId=
</varname></term>
844 <para>Specifies the peer tunnel id. Takes a number in the range
1—
4294967295. The value used must
845 match the
<literal>PeerTunnelId=
</literal> value being used at the peer. This setting is
850 <term><varname>Remote=
</varname></term>
852 <para>Specifies the IP address of the remote peer. This setting is compulsory.
</para>
856 <term><varname>Local=
</varname></term>
858 <para>Specifies the IP address of the local interface. Takes an IP address, or the special values
859 <literal>auto
</literal>,
<literal>static
</literal>, or
<literal>dynamic
</literal>. When an address
860 is set, then the local interface must have the address. If
<literal>auto
</literal>, then one of the
861 addresses on the local interface is used. Similarly, if
<literal>static
</literal> or
862 <literal>dynamic
</literal> is set, then one of the static or dynamic addresses on the local
863 interface is used. Defaults to
<literal>auto
</literal>.
</para>
867 <term><varname>EncapsulationType=
</varname></term>
869 <para>Specifies the encapsulation type of the tunnel. Takes one of
<literal>udp
</literal> or
870 <literal>ip
</literal>.
</para>
874 <term><varname>UDPSourcePort=
</varname></term>
876 <para>Specifies the UDP source port to be used for the tunnel. When UDP encapsulation is selected
877 it's mandatory. Ignored when IP encapsulation is selected.
</para>
881 <term><varname>UDPDestinationPort=
</varname></term>
883 <para>Specifies destination port. When UDP encapsulation is selected it's mandatory. Ignored when IP
884 encapsulation is selected.
</para>
888 <term><varname>UDPChecksum=
</varname></term>
890 <para>Takes a boolean. When true, specifies that UDP checksum is calculated for transmitted packets
895 <term><varname>UDP6ZeroChecksumTx=
</varname></term>
897 <para>Takes a boolean. When true, skip UDP checksum calculation for transmitted packets over IPv6.
</para>
901 <term><varname>UDP6ZeroChecksumRx=
</varname></term>
903 <para>Takes a boolean. When true, allows incoming UDP packets over IPv6 with zero checksum field.
</para>
910 <title>[L2TPSession] Section Options
</title>
912 <para>The [L2TPSession] section only applies for
913 netdevs of kind
<literal>l2tp
</literal>, and accepts the
914 following keys:
</para>
915 <variablelist class='network-directives'
>
917 <term><varname>Name=
</varname></term>
919 <para>Specifies the name of the session. This setting is compulsory.
</para>
923 <term><varname>SessionId=
</varname></term>
925 <para>Specifies the session identifier. Takes an number in the range
1–
4294967295. The value used
926 must match the
<literal>SessionId=
</literal> value being used at the peer. This setting is
931 <term><varname>PeerSessionId=
</varname></term>
933 <para>Specifies the peer session identifier. Takes an number in the range
1–
4294967295.
934 The value used must match the
<literal>PeerSessionId=
</literal> value being used at the peer.
935 This setting is compulsory.
</para>
939 <term><varname>Layer2SpecificHeader=
</varname></term>
941 <para>Specifies layer2specific header type of the session. One of
<literal>none
</literal> or
<literal>default
</literal>. Defaults to
<literal>default
</literal>.
</para>
948 <title>[MACsec] Section Options
</title>
950 <para>The [MACsec] section only applies for network devices of kind
951 <literal>macsec
</literal>, and accepts the following keys:
</para>
953 <variablelist class='network-directives'
>
955 <term><varname>Port=
</varname></term>
957 <para>Specifies the port to be used for the MACsec transmit channel. The port is used to make
958 secure channel identifier (SCI). Takes a value between
1 and
65535. Defaults to unset.
963 <term><varname>Encrypt=
</varname></term>
965 <para>Takes a boolean. When true, enable encryption. Defaults to unset.
</para>
972 <title>[MACsecReceiveChannel] Section Options
</title>
973 <para>The [MACsecReceiveChannel] section only applies for network devices of
974 kind
<literal>macsec
</literal>, and accepts the following keys:
</para>
976 <variablelist class='network-directives'
>
978 <term><varname>Port=
</varname></term>
980 <para>Specifies the port to be used for the MACsec receive channel. The port is used to make
981 secure channel identifier (SCI). Takes a value between
1 and
65535. This option is
982 compulsory, and is not set by default.
</para>
986 <term><varname>MACAddress=
</varname></term>
988 <para>Specifies the MAC address to be used for the MACsec receive channel. The MAC address
989 used to make secure channel identifier (SCI). This setting is compulsory, and is not set by
997 <title>[MACsecTransmitAssociation] Section Options
</title>
999 <para>The [MACsecTransmitAssociation] section only applies for network devices
1000 of kind
<literal>macsec
</literal>, and accepts the following keys:
</para>
1002 <variablelist class='network-directives'
>
1004 <term><varname>PacketNumber=
</varname></term>
1006 <para>Specifies the packet number to be used for replay protection and the construction of
1007 the initialization vector (along with the secure channel identifier [SCI]). Takes a value
1008 between
1-
4,
294,
967,
295. Defaults to unset.
1013 <term><varname>KeyId=
</varname></term>
1015 <para>Specifies the identification for the key. Takes a number between
0-
255. This option
1016 is compulsory, and is not set by default.
</para>
1020 <term><varname>Key=
</varname></term>
1022 <para>Specifies the encryption key used in the transmission channel. The same key must be
1023 configured on the peer’s matching receive channel. This setting is compulsory, and is not set
1024 by default. Takes a
128-bit key encoded in a hexadecimal string, for example
1025 <literal>dffafc8d7b9a43d5b9a3dfbbf6a30c16
</literal>.
</para>
1029 <term><varname>KeyFile=
</varname></term>
1031 <para>Takes a absolute path to a file which contains a
128-bit key encoded in a hexadecimal string,
1032 which will be used in the transmission channel. When this option is specified,
1033 <varname>Key=
</varname> is ignored. Note that the file must be readable by the user
1034 <literal>systemd-network
</literal>, so it should be, e.g., owned by
1035 <literal>root:systemd-network
</literal> with a
<literal>0640</literal> file mode. If the path
1036 refers to an
<constant>AF_UNIX
</constant> stream socket in the file system a connection is made to
1037 it and the key read from it.
</para>
1041 <term><varname>Activate=
</varname></term>
1043 <para>Takes a boolean. If enabled, then the security association is activated. Defaults to
1048 <term><varname>UseForEncoding=
</varname></term>
1050 <para>Takes a boolean. If enabled, then the security association is used for encoding. Only
1051 one [MACsecTransmitAssociation] section can enable this option. When enabled,
1052 <varname>Activate=yes
</varname> is implied. Defaults to unset.
</para>
1059 <title>[MACsecReceiveAssociation] Section Options
</title>
1061 <para>The [MACsecReceiveAssociation] section only applies for
1062 network devices of kind
<literal>macsec
</literal>, and accepts the
1063 following keys:
</para>
1065 <variablelist class='network-directives'
>
1067 <term><varname>Port=
</varname></term>
1069 <para>Accepts the same key in [MACsecReceiveChannel] section.
</para>
1073 <term><varname>MACAddress=
</varname></term>
1075 <para>Accepts the same key in [MACsecReceiveChannel] section.
</para>
1079 <term><varname>PacketNumber=
</varname></term>
1081 <para>Accepts the same key in [MACsecTransmitAssociation] section.
</para>
1085 <term><varname>KeyId=
</varname></term>
1087 <para>Accepts the same key in [MACsecTransmitAssociation] section.
</para>
1091 <term><varname>Key=
</varname></term>
1093 <para>Accepts the same key in [MACsecTransmitAssociation] section.
</para>
1097 <term><varname>KeyFile=
</varname></term>
1099 <para>Accepts the same key in [MACsecTransmitAssociation] section.
</para>
1103 <term><varname>Activate=
</varname></term>
1105 <para>Accepts the same key in [MACsecTransmitAssociation] section.
</para>
1112 <title>[Tunnel] Section Options
</title>
1114 <para>The [Tunnel] section only applies for
1116 <literal>ipip
</literal>,
1117 <literal>sit
</literal>,
1118 <literal>gre
</literal>,
1119 <literal>gretap
</literal>,
1120 <literal>ip6gre
</literal>,
1121 <literal>ip6gretap
</literal>,
1122 <literal>vti
</literal>,
1123 <literal>vti6
</literal>,
1124 <literal>ip6tnl
</literal>, and
1125 <literal>erspan
</literal> and accepts
1126 the following keys:
</para>
1128 <variablelist class='network-directives'
>
1130 <term><varname>Local=
</varname></term>
1132 <para>A static local address for tunneled packets. It must be an address on another interface of
1133 this host, or the special value
<literal>any
</literal>.
</para>
1137 <term><varname>Remote=
</varname></term>
1139 <para>The remote endpoint of the tunnel. Takes an IP address or the special value
1140 <literal>any
</literal>.
</para>
1144 <term><varname>TOS=
</varname></term>
1146 <para>The Type Of Service byte value for a tunnel interface.
1147 For details about the TOS, see the
1148 <ulink url=
"http://tools.ietf.org/html/rfc1349"> Type of
1149 Service in the Internet Protocol Suite
</ulink> document.
1154 <term><varname>TTL=
</varname></term>
1156 <para>A fixed Time To Live N on tunneled packets. N is a
1157 number in the range
1–
255.
0 is a special value meaning that
1158 packets inherit the TTL value. The default value for IPv4
1159 tunnels is
0 (inherit). The default value for IPv6 tunnels is
1164 <term><varname>DiscoverPathMTU=
</varname></term>
1166 <para>Takes a boolean. When true, enables Path MTU Discovery on
1171 <term><varname>IPv6FlowLabel=
</varname></term>
1173 <para>Configures the
20-bit flow label (see
<ulink url=
"https://tools.ietf.org/html/rfc6437">
1174 RFC
6437</ulink>) field in the IPv6 header (see
<ulink url=
"https://tools.ietf.org/html/rfc2460">
1175 RFC
2460</ulink>), which is used by a node to label packets of a flow.
1176 It is only used for IPv6 tunnels.
1177 A flow label of zero is used to indicate packets that have
1179 It can be configured to a value in the range
0–
0xFFFFF, or be
1180 set to
<literal>inherit
</literal>, in which case the original flowlabel is used.
</para>
1184 <term><varname>CopyDSCP=
</varname></term>
1186 <para>Takes a boolean. When true, the Differentiated Service Code
1187 Point (DSCP) field will be copied to the inner header from
1188 outer header during the decapsulation of an IPv6 tunnel
1189 packet. DSCP is a field in an IP packet that enables different
1190 levels of service to be assigned to network traffic.
1191 Defaults to
<literal>no
</literal>.
1196 <term><varname>EncapsulationLimit=
</varname></term>
1198 <para>The Tunnel Encapsulation Limit option specifies how many additional
1199 levels of encapsulation are permitted to be prepended to the packet.
1200 For example, a Tunnel Encapsulation Limit option containing a limit
1201 value of zero means that a packet carrying that option may not enter
1202 another tunnel before exiting the current tunnel.
1203 (see
<ulink url=
"https://tools.ietf.org/html/rfc2473#section-4.1.1"> RFC
2473</ulink>).
1204 The valid range is
0–
255 and
<literal>none
</literal>. Defaults to
4.
1209 <term><varname>Key=
</varname></term>
1211 <para>The
<varname>Key=
</varname> parameter specifies the same key to use in
1212 both directions (
<varname>InputKey=
</varname> and
<varname>OutputKey=
</varname>).
1213 The
<varname>Key=
</varname> is either a number or an IPv4 address-like dotted quad.
1214 It is used as mark-configured SAD/SPD entry as part of the lookup key (both in data
1215 and control path) in IP XFRM (framework used to implement IPsec protocol).
1216 See
<ulink url=
"http://man7.org/linux/man-pages/man8/ip-xfrm.8.html">
1217 ip-xfrm — transform configuration
</ulink> for details. It is only used for VTI/VTI6,
1218 GRE, GRETAP, and ERSPAN tunnels.
</para>
1222 <term><varname>InputKey=
</varname></term>
1224 <para>The
<varname>InputKey=
</varname> parameter specifies the key to use for input.
1225 The format is same as
<varname>Key=
</varname>. It is only used for VTI/VTI6, GRE, GRETAP,
1226 and ERSPAN tunnels.
</para>
1230 <term><varname>OutputKey=
</varname></term>
1232 <para>The
<varname>OutputKey=
</varname> parameter specifies the key to use for output.
1233 The format is same as
<varname>Key=
</varname>. It is only used for VTI/VTI6, GRE, GRETAP,
1234 and ERSPAN tunnels.
</para>
1238 <term><varname>Mode=
</varname></term>
1240 <para>An
<literal>ip6tnl
</literal> tunnel can be in one of three
1242 <literal>ip6ip6
</literal> for IPv6 over IPv6,
1243 <literal>ipip6
</literal> for IPv4 over IPv6 or
1244 <literal>any
</literal> for either.
1249 <term><varname>Independent=
</varname></term>
1251 <para>Takes a boolean. When true tunnel does not require .network file. Created as
"tunnel@NONE".
1252 Defaults to
<literal>false
</literal>.
1257 <term><varname>AssignToLoopback=
</varname></term>
1259 <para>Takes a boolean. If set to
<literal>yes
</literal>, the loopback interface
<literal>lo
</literal>
1260 is used as the underlying device of the tunnel interface. Defaults to
<literal>no
</literal>.
</para>
1264 <term><varname>AllowLocalRemote=
</varname></term>
1266 <para>Takes a boolean. When true allows tunnel traffic on
<varname>ip6tnl
</varname> devices where the remote endpoint is a local host address.
1267 When unset, the kernel's default will be used.
1272 <term><varname>FooOverUDP=
</varname></term>
1274 <para>Takes a boolean. Specifies whether
<varname>FooOverUDP=
</varname> tunnel is to be configured.
1275 Defaults to false. This takes effects only for IPIP, SIT, GRE, and GRETAP tunnels.
1276 For more detail information see
1277 <ulink url=
"https://lwn.net/Articles/614348">Foo over UDP
</ulink></para>
1281 <term><varname>FOUDestinationPort=
</varname></term>
1283 <para>This setting specifies the UDP destination port for encapsulation.
1284 This field is mandatory when
<varname>FooOverUDP=yes
</varname>, and is not set by default.
</para>
1288 <term><varname>FOUSourcePort=
</varname></term>
1290 <para>This setting specifies the UDP source port for encapsulation. Defaults to
<constant>0</constant>
1291 — that is, the source port for packets is left to the network stack to decide.
</para>
1295 <term><varname>Encapsulation=
</varname></term>
1297 <para>Accepts the same key as in the [FooOverUDP] section.
</para>
1301 <term><varname>IPv6RapidDeploymentPrefix=
</varname></term>
1303 <para>Reconfigure the tunnel for
<ulink url=
"https://tools.ietf.org/html/rfc5569">IPv6 Rapid
1304 Deployment
</ulink>, also known as
6rd. The value is an ISP-specific IPv6 prefix with a non-zero length. Only
1305 applicable to SIT tunnels.
</para>
1309 <term><varname>ISATAP=
</varname></term>
1311 <para>Takes a boolean. If set, configures the tunnel as Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) tunnel.
1312 Only applicable to SIT tunnels. When unset, the kernel's default will be used.
</para>
1316 <term><varname>SerializeTunneledPackets=
</varname></term>
1318 <para>Takes a boolean. If set to yes, then packets are serialized. Only applies for GRE,
1319 GRETAP, and ERSPAN tunnels. When unset, the kernel's default will be used.
1324 <term><varname>ERSPANIndex=
</varname></term>
1326 <para>Specifies the ERSPAN index field for the interface, an integer in the range
1-
1048575 associated with
1327 the ERSPAN traffic's source port and direction. This field is mandatory.
1335 <title>[FooOverUDP] Section Options
</title>
1337 <para>The [FooOverUDP] section only applies for
1338 netdevs of kind
<literal>fou
</literal> and accepts the
1339 following keys:
</para>
1341 <variablelist class='network-directives'
>
1343 <term><varname>Encapsulation=
</varname></term>
1345 <para>Specifies the encapsulation mechanism used to store networking packets of various protocols
1346 inside the UDP packets. Supports the following values:
1348 <literal>FooOverUDP
</literal> provides the simplest no frills model of UDP encapsulation, it simply
1349 encapsulates packets directly in the UDP payload.
<literal>GenericUDPEncapsulation
</literal> is a
1350 generic and extensible encapsulation, it allows encapsulation of packets for any IP protocol and
1351 optional data as part of the encapsulation. For more detailed information see
<ulink
1352 url=
"https://lwn.net/Articles/615044">Generic UDP Encapsulation
</ulink>. Defaults to
1353 <literal>FooOverUDP
</literal>.
1358 <term><varname>Port=
</varname></term>
1360 <para>Specifies the port number, where the IP encapsulation packets will arrive. Please take note
1361 that the packets will arrive with the encapsulation will be removed. Then they will be manually fed
1362 back into the network stack, and sent ahead for delivery to the real destination. This option is
1367 <term><varname>PeerPort=
</varname></term>
1369 <para>Specifies the peer port number. Defaults to unset. Note that when peer port is set
1370 <literal>Peer=
</literal> address is mandatory.
</para>
1374 <term><varname>Protocol=
</varname></term>
1376 <para>The
<varname>Protocol=
</varname> specifies the protocol number of the packets arriving
1377 at the UDP port. When
<varname>Encapsulation=FooOverUDP
</varname>, this field is mandatory
1378 and is not set by default. Takes an IP protocol name such as
<literal>gre
</literal> or
1379 <literal>ipip
</literal>, or an integer within the range
1-
255. When
1380 <varname>Encapsulation=GenericUDPEncapsulation
</varname>, this must not be specified.
</para>
1384 <term><varname>Peer=
</varname></term>
1386 <para>Configures peer IP address. Note that when peer address is set
<literal>PeerPort=
</literal>
1387 is mandatory.
</para>
1391 <term><varname>Local=
</varname></term>
1393 <para>Configures local IP address.
</para>
1400 <title>[Peer] Section Options
</title>
1402 <para>The [Peer] section only applies for
1403 netdevs of kind
<literal>veth
</literal> and accepts the
1404 following keys:
</para>
1406 <variablelist class='network-directives'
>
1408 <term><varname>Name=
</varname></term>
1410 <para>The interface name used when creating the netdev.
1411 This setting is compulsory.
</para>
1415 <term><varname>MACAddress=
</varname></term>
1417 <para>The peer MACAddress, if not set, it is generated in
1418 the same way as the MAC address of the main
1426 <title>[VXCAN] Section Options
</title>
1428 <para>The [VXCAN] section only applies for
1429 netdevs of kind
<literal>vxcan
</literal> and accepts the
1430 following key:
</para>
1432 <variablelist class='network-directives'
>
1434 <term><varname>Peer=
</varname></term>
1436 <para>The peer interface name used when creating the netdev.
1437 This setting is compulsory.
</para>
1444 <title>[Tun] Section Options
</title>
1446 <para>The [Tun] section only applies for
1447 netdevs of kind
<literal>tun
</literal>, and accepts the following
1450 <variablelist class='network-directives'
>
1452 <term><varname>MultiQueue=
</varname></term>
1453 <listitem><para>Takes a boolean. Configures whether
1454 to use multiple file descriptors (queues) to parallelize
1455 packets sending and receiving. Defaults to
1456 <literal>no
</literal>.
</para>
1460 <term><varname>PacketInfo=
</varname></term>
1461 <listitem><para>Takes a boolean. Configures whether
1462 packets should be prepended with four extra bytes (two flag
1463 bytes and two protocol bytes). If disabled, it indicates that
1464 the packets will be pure IP packets. Defaults to
1465 <literal>no
</literal>.
</para>
1469 <term><varname>VNetHeader=
</varname></term>
1470 <listitem><para>Takes a boolean. Configures
1471 IFF_VNET_HDR flag for a tun or tap device. It allows sending
1472 and receiving larger Generic Segmentation Offload (GSO)
1473 packets. This may increase throughput significantly.
1475 <literal>no
</literal>.
</para>
1479 <term><varname>User=
</varname></term>
1480 <listitem><para>User to grant access to the
1481 <filename>/dev/net/tun
</filename> device.
</para>
1485 <term><varname>Group=
</varname></term>
1486 <listitem><para>Group to grant access to the
1487 <filename>/dev/net/tun
</filename> device.
</para>
1494 <title>[Tap] Section Options
</title>
1496 <para>The [Tap] section only applies for
1497 netdevs of kind
<literal>tap
</literal>, and accepts the same keys
1498 as the [Tun] section.
</para>
1502 <title>[WireGuard] Section Options
</title>
1504 <para>The [WireGuard] section accepts the following
1507 <variablelist class='network-directives'
>
1509 <term><varname>PrivateKey=
</varname></term>
1511 <para>The Base64 encoded private key for the interface. It can be
1512 generated using the
<command>wg genkey
</command> command
1513 (see
<citerefentry project=
"wireguard"><refentrytitle>wg
</refentrytitle><manvolnum>8</manvolnum></citerefentry>).
1514 This option or
<varname>PrivateKeyFile=
</varname> is mandatory to use WireGuard.
1515 Note that because this information is secret, you may want to set
1516 the permissions of the .netdev file to be owned by
<literal>root:systemd-network
</literal>
1517 with a
<literal>0640</literal> file mode.
</para>
1521 <term><varname>PrivateKeyFile=
</varname></term>
1523 <para>Takes an absolute path to a file which contains the Base64 encoded private key for the
1524 interface. When this option is specified, then
<varname>PrivateKey=
</varname> is ignored. Note
1525 that the file must be readable by the user
<literal>systemd-network
</literal>, so it should be,
1526 e.g., owned by
<literal>root:systemd-network
</literal> with a
<literal>0640</literal> file mode. If
1527 the path refers to an
<constant>AF_UNIX
</constant> stream socket in the file system a connection is
1528 made to it and the key read from it.
</para>
1532 <term><varname>ListenPort=
</varname></term>
1534 <para>Sets UDP port for listening. Takes either value between
1 and
65535
1535 or
<literal>auto
</literal>. If
<literal>auto
</literal> is specified,
1536 the port is automatically generated based on interface name.
1537 Defaults to
<literal>auto
</literal>.
</para>
1541 <term><varname>FirewallMark=
</varname></term>
1543 <para>Sets a firewall mark on outgoing WireGuard packets from this interface. Takes a number between
1 and
4294967295.
</para>
1550 <title>[WireGuardPeer] Section Options
</title>
1552 <para>The [WireGuardPeer] section accepts the following
1555 <variablelist class='network-directives'
>
1557 <term><varname>PublicKey=
</varname></term>
1559 <para>Sets a Base64 encoded public key calculated by
<command>wg pubkey
</command>
1560 (see
<citerefentry project=
"wireguard"><refentrytitle>wg
</refentrytitle><manvolnum>8</manvolnum></citerefentry>)
1561 from a private key, and usually transmitted out of band to the
1562 author of the configuration file. This option is mandatory for this
1567 <term><varname>PresharedKey=
</varname></term>
1569 <para>Optional preshared key for the interface. It can be generated
1570 by the
<command>wg genpsk
</command> command. This option adds an
1571 additional layer of symmetric-key cryptography to be mixed into the
1572 already existing public-key cryptography, for post-quantum
1574 Note that because this information is secret, you may want to set
1575 the permissions of the .netdev file to be owned by
<literal>root:systemd-network
</literal>
1576 with a
<literal>0640</literal> file mode.
</para>
1580 <term><varname>PresharedKeyFile=
</varname></term>
1582 <para>Takes an absolute path to a file which contains the Base64 encoded preshared key for the
1583 peer. When this option is specified, then
<varname>PresharedKey=
</varname> is ignored. Note that
1584 the file must be readable by the user
<literal>systemd-network
</literal>, so it should be, e.g.,
1585 owned by
<literal>root:systemd-network
</literal> with a
<literal>0640</literal> file mode. If the
1586 path refers to an
<constant>AF_UNIX
</constant> stream socket in the file system a connection is
1587 made to it and the key read from it.
</para>
1591 <term><varname>AllowedIPs=
</varname></term>
1593 <para>Sets a comma-separated list of IP (v4 or v6) addresses with CIDR masks
1594 from which this peer is allowed to send incoming traffic and to
1595 which outgoing traffic for this peer is directed. The catch-all
1596 0.0.0.0/
0 may be specified for matching all IPv4 addresses, and
1597 ::/
0 may be specified for matching all IPv6 addresses.
</para>
1601 <term><varname>Endpoint=
</varname></term>
1603 <para>Sets an endpoint IP address or hostname, followed by a colon, and then
1604 a port number. This endpoint will be updated automatically once to
1605 the most recent source IP address and port of correctly
1606 authenticated packets from the peer at configuration time.
</para>
1610 <term><varname>PersistentKeepalive=
</varname></term>
1612 <para>Sets a seconds interval, between
1 and
65535 inclusive, of how often
1613 to send an authenticated empty packet to the peer for the purpose
1614 of keeping a stateful firewall or NAT mapping valid persistently.
1615 For example, if the interface very rarely sends traffic, but it
1616 might at anytime receive traffic from a peer, and it is behind NAT,
1617 the interface might benefit from having a persistent keepalive
1618 interval of
25 seconds. If set to
0 or
"off", this option is
1619 disabled. By default or when unspecified, this option is off.
1620 Most users will not need this.
</para>
1627 <title>[Bond] Section Options
</title>
1629 <para>The [Bond] section accepts the following
1632 <variablelist class='network-directives'
>
1634 <term><varname>Mode=
</varname></term>
1636 <para>Specifies one of the bonding policies. The default is
1637 <literal>balance-rr
</literal> (round robin). Possible values are
1638 <literal>balance-rr
</literal>,
1639 <literal>active-backup
</literal>,
1640 <literal>balance-xor
</literal>,
1641 <literal>broadcast
</literal>,
1642 <literal>802.3ad
</literal>,
1643 <literal>balance-tlb
</literal>, and
1644 <literal>balance-alb
</literal>.
1650 <term><varname>TransmitHashPolicy=
</varname></term>
1652 <para>Selects the transmit hash policy to use for slave
1653 selection in balance-xor,
802.3ad, and tlb modes. Possible
1655 <literal>layer2
</literal>,
1656 <literal>layer3+
4</literal>,
1657 <literal>layer2+
3</literal>,
1658 <literal>encap2+
3</literal>, and
1659 <literal>encap3+
4</literal>.
1665 <term><varname>LACPTransmitRate=
</varname></term>
1667 <para>Specifies the rate with which link partner transmits
1668 Link Aggregation Control Protocol Data Unit packets in
1669 802.3ad mode. Possible values are
<literal>slow
</literal>,
1670 which requests partner to transmit LACPDUs every
30 seconds,
1671 and
<literal>fast
</literal>, which requests partner to
1672 transmit LACPDUs every second. The default value is
1673 <literal>slow
</literal>.
</para>
1678 <term><varname>MIIMonitorSec=
</varname></term>
1680 <para>Specifies the frequency that Media Independent
1681 Interface link monitoring will occur. A value of zero
1682 disables MII link monitoring. This value is rounded down to
1683 the nearest millisecond. The default value is
0.
</para>
1688 <term><varname>UpDelaySec=
</varname></term>
1690 <para>Specifies the delay before a link is enabled after a
1691 link up status has been detected. This value is rounded down
1692 to a multiple of MIIMonitorSec. The default value is
1698 <term><varname>DownDelaySec=
</varname></term>
1700 <para>Specifies the delay before a link is disabled after a
1701 link down status has been detected. This value is rounded
1702 down to a multiple of MIIMonitorSec. The default value is
1708 <term><varname>LearnPacketIntervalSec=
</varname></term>
1710 <para>Specifies the number of seconds between instances where the bonding
1711 driver sends learning packets to each slave peer switch.
1712 The valid range is
1–
0x7fffffff; the default value is
1. This option
1713 has an effect only for the balance-tlb and balance-alb modes.
</para>
1718 <term><varname>AdSelect=
</varname></term>
1720 <para>Specifies the
802.3ad aggregation selection logic to use. Possible values are
1721 <literal>stable
</literal>,
1722 <literal>bandwidth
</literal> and
1723 <literal>count
</literal>.
1729 <term><varname>AdActorSystemPriority=
</varname></term>
1731 <para>Specifies the
802.3ad actor system priority. Takes a number in the range
1—
65535.
</para>
1736 <term><varname>AdUserPortKey=
</varname></term>
1738 <para>Specifies the
802.3ad user defined portion of the port key. Takes a number in the range
1744 <term><varname>AdActorSystem=
</varname></term>
1746 <para>Specifies the
802.3ad system mac address. This can not be either NULL or Multicast.
</para>
1751 <term><varname>FailOverMACPolicy=
</varname></term>
1753 <para>Specifies whether the active-backup mode should set all slaves to
1754 the same MAC address at the time of enslavement or, when enabled, to perform special handling of the
1755 bond's MAC address in accordance with the selected policy. The default policy is none.
1757 <literal>none
</literal>,
1758 <literal>active
</literal> and
1759 <literal>follow
</literal>.
1765 <term><varname>ARPValidate=
</varname></term>
1767 <para>Specifies whether or not ARP probes and replies should be
1768 validated in any mode that supports ARP monitoring, or whether
1769 non-ARP traffic should be filtered (disregarded) for link
1770 monitoring purposes. Possible values are
1771 <literal>none
</literal>,
1772 <literal>active
</literal>,
1773 <literal>backup
</literal> and
1774 <literal>all
</literal>.
1780 <term><varname>ARPIntervalSec=
</varname></term>
1782 <para>Specifies the ARP link monitoring frequency. A value of
0 disables ARP monitoring. The
1783 default value is
0, and the default unit seconds.
1789 <term><varname>ARPIPTargets=
</varname></term>
1791 <para>Specifies the IP addresses to use as ARP monitoring peers when
1792 ARPIntervalSec is greater than
0. These are the targets of the ARP request
1793 sent to determine the health of the link to the targets.
1794 Specify these values in IPv4 dotted decimal format. At least one IP
1795 address must be given for ARP monitoring to function. The
1796 maximum number of targets that can be specified is
16. The
1797 default value is no IP addresses.
1803 <term><varname>ARPAllTargets=
</varname></term>
1805 <para>Specifies the quantity of ARPIPTargets that must be reachable
1806 in order for the ARP monitor to consider a slave as being up.
1807 This option affects only active-backup mode for slaves with
1808 ARPValidate enabled. Possible values are
1809 <literal>any
</literal> and
1810 <literal>all
</literal>.
1816 <term><varname>PrimaryReselectPolicy=
</varname></term>
1818 <para>Specifies the reselection policy for the primary slave. This
1819 affects how the primary slave is chosen to become the active slave
1820 when failure of the active slave or recovery of the primary slave
1821 occurs. This option is designed to prevent flip-flopping between
1822 the primary slave and other slaves. Possible values are
1823 <literal>always
</literal>,
1824 <literal>better
</literal> and
1825 <literal>failure
</literal>.
1831 <term><varname>ResendIGMP=
</varname></term>
1833 <para>Specifies the number of IGMP membership reports to be issued after
1834 a failover event. One membership report is issued immediately after
1835 the failover, subsequent packets are sent in each
200ms interval.
1836 The valid range is
0–
255. Defaults to
1. A value of
0
1837 prevents the IGMP membership report from being issued in response
1838 to the failover event.
1844 <term><varname>PacketsPerSlave=
</varname></term>
1846 <para>Specify the number of packets to transmit through a slave before
1847 moving to the next one. When set to
0, then a slave is chosen at
1848 random. The valid range is
0–
65535. Defaults to
1. This option
1849 only has effect when in balance-rr mode.
1855 <term><varname>GratuitousARP=
</varname></term>
1857 <para>Specify the number of peer notifications (gratuitous ARPs and
1858 unsolicited IPv6 Neighbor Advertisements) to be issued after a
1859 failover event. As soon as the link is up on the new slave,
1860 a peer notification is sent on the bonding device and each
1861 VLAN sub-device. This is repeated at each link monitor interval
1862 (ARPIntervalSec or MIIMonitorSec, whichever is active) if the number is
1863 greater than
1. The valid range is
0–
255. The default value is
1.
1864 These options affect only the active-backup mode.
1870 <term><varname>AllSlavesActive=
</varname></term>
1872 <para>Takes a boolean. Specifies that duplicate frames (received on inactive ports)
1873 should be dropped when false, or delivered when true. Normally, bonding will drop
1874 duplicate frames (received on inactive ports), which is desirable for
1875 most users. But there are some times it is nice to allow duplicate
1876 frames to be delivered. The default value is false (drop duplicate frames
1877 received on inactive ports).
1883 <term><varname>DynamicTransmitLoadBalancing=
</varname></term>
1885 <para>Takes a boolean. Specifies if dynamic shuffling of flows is enabled. Applies only
1886 for balance-tlb mode. Defaults to unset.
1892 <term><varname>MinLinks=
</varname></term>
1894 <para>Specifies the minimum number of links that must be active before
1895 asserting carrier. The default value is
0.
1901 <para>For more detail information see
1902 <ulink url=
"https://www.kernel.org/doc/Documentation/networking/bonding.txt">
1903 Linux Ethernet Bonding Driver HOWTO
</ulink></para>
1907 <title>[Xfrm] Section Options
</title>
1909 <para>The [Xfrm] section accepts the following
1912 <variablelist class='network-directives'
>
1914 <term><varname>InterfaceId=
</varname></term>
1916 <para>Sets the ID/key of the xfrm interface which needs to be associated with a SA/policy.
1917 Can be decimal or hexadecimal, valid range is
0-
0xffffffff, defaults to
0.
</para>
1921 <term><varname>Independent=
</varname></term>
1923 <para>Takes a boolean. If set to
<literal>no
</literal>, the xfrm interface should have an
1924 underlying device which can be used for hardware offloading. Defaults to
<literal>no
</literal>.
1925 See
<citerefentry><refentrytitle>systemd.network
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
1926 for how to configure the underlying device.
</para>
1931 <para>For more detail information see
1932 <ulink url=
"https://lwn.net/Articles/757391">Virtual XFRM Interfaces
</ulink>.
</para>
1936 <title>[VRF] Section Options
</title>
1937 <para>The [VRF] section only applies for
1938 netdevs of kind
<literal>vrf
</literal> and accepts the
1939 following key:
</para>
1941 <variablelist class='network-directives'
>
1943 <term><varname>Table=
</varname></term>
1945 <para>The numeric routing table identifier. This setting is compulsory.
</para>
1952 <title>Examples
</title>
1954 <title>/etc/systemd/network/
25-bridge.netdev
</title>
1956 <programlisting>[NetDev]
1958 Kind=bridge
</programlisting>
1962 <title>/etc/systemd/network/
25-vlan1.netdev
</title>
1964 <programlisting>[Match]
1972 Id=
1</programlisting>
1975 <title>/etc/systemd/network/
25-ipip.netdev
</title>
1976 <programlisting>[NetDev]
1982 Local=
192.168.223.238
1983 Remote=
192.169.224.239
1984 TTL=
64</programlisting>
1987 <title>/etc/systemd/network/
1-fou-tunnel.netdev
</title>
1988 <programlisting>[NetDev]
1998 <title>/etc/systemd/network/
25-fou-ipip.netdev
</title>
1999 <programlisting>[NetDev]
2006 Remote=
10.65.208.211
2008 FOUDestinationPort=
5555
2012 <title>/etc/systemd/network/
25-tap.netdev
</title>
2013 <programlisting>[NetDev]
2019 PacketInfo=yes
</programlisting> </example>
2022 <title>/etc/systemd/network/
25-sit.netdev
</title>
2023 <programlisting>[NetDev]
2030 Remote=
10.65.223.239</programlisting>
2034 <title>/etc/systemd/network/
25-
6rd.netdev
</title>
2035 <programlisting>[NetDev]
2042 IPv6RapidDeploymentPrefix=
2602::/
24</programlisting>
2046 <title>/etc/systemd/network/
25-gre.netdev
</title>
2047 <programlisting>[NetDev]
2054 Remote=
10.65.223.239</programlisting>
2058 <title>/etc/systemd/network/
25-ip6gre.netdev
</title>
2059 <programlisting>[NetDev]
2064 Key=
123</programlisting>
2068 <title>/etc/systemd/network/
25-vti.netdev
</title>
2070 <programlisting>[NetDev]
2077 Remote=
10.65.223.239</programlisting>
2081 <title>/etc/systemd/network/
25-veth.netdev
</title>
2082 <programlisting>[NetDev]
2087 Name=veth-peer
</programlisting>
2091 <title>/etc/systemd/network/
25-bond.netdev
</title>
2092 <programlisting>[NetDev]
2098 TransmitHashPolicy=layer3+
4
2100 LACPTransmitRate=fast
2105 <title>/etc/systemd/network/
25-dummy.netdev
</title>
2106 <programlisting>[NetDev]
2109 MACAddress=
12:
34:
56:
78:
9a:bc
</programlisting>
2112 <title>/etc/systemd/network/
25-vrf.netdev
</title>
2113 <para>Create a VRF interface with table
42.
</para>
2114 <programlisting>[NetDev]
2119 Table=
42</programlisting>
2123 <title>/etc/systemd/network/
25-macvtap.netdev
</title>
2124 <para>Create a MacVTap device.
</para>
2125 <programlisting>[NetDev]
2131 <title>/etc/systemd/network/
25-wireguard.netdev
</title>
2132 <programlisting>[NetDev]
2137 PrivateKey=EEGlnEPYJV//kbvvIqxKkQwOiS+UENyPncC4bF46ong=
2141 PublicKey=RDf+LSpeEre7YEIKaxg+wbpsNV7du+ktR99uBEtIiCA=
2142 AllowedIPs=fd31:bf08:
57cb::/
48,
192.168.26.0/
24
2143 Endpoint=wireguard.example.com:
51820</programlisting>
2147 <title>/etc/systemd/network/
27-xfrm.netdev
</title>
2148 <programlisting>[NetDev]
2153 Independent=yes
</programlisting>
2158 <title>See Also
</title>
2160 <citerefentry><refentrytitle>systemd
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
2161 <citerefentry><refentrytitle>systemd-networkd
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
2162 <citerefentry><refentrytitle>systemd.link
</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
2163 <citerefentry><refentrytitle>systemd.network
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
projects / thirdparty / systemd.git / blob