1 <?xml version='1.0'?> <!--*-nxml-*-->
2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
3 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
6 This file is part of systemd.
8 Copyright 2013 Tom Gundersen
10 systemd is free software; you can redistribute it and/or modify it
11 under the terms of the GNU Lesser General Public License as published by
12 the Free Software Foundation; either version 2.1 of the License, or
13 (at your option) any later version.
15 systemd is distributed in the hope that it will be useful, but
16 WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 Lesser General Public License for more details.
20 You should have received a copy of the GNU Lesser General Public License
21 along with systemd; If not, see <http://www.gnu.org/licenses/>.
24 <refentry id="systemd.netdev" conditional='ENABLE_NETWORKD'>
27 <title>systemd.network</title>
28 <productname>systemd</productname>
32 <contrib>Developer</contrib>
33 <firstname>Tom</firstname>
34 <surname>Gundersen</surname>
35 <email>teg@jklm.no</email>
41 <refentrytitle>systemd.netdev</refentrytitle>
42 <manvolnum>5</manvolnum>
46 <refname>systemd.netdev</refname>
47 <refpurpose>Virtual Network Device configuration</refpurpose>
51 <para><filename><replaceable>netdev</replaceable>.netdev</filename></para>
55 <title>Description</title>
57 <para>Network setup is performed by
58 <citerefentry><refentrytitle>systemd-networkd</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
61 <para>Virtual Network Device files must have the extension
62 <filename>.netdev</filename>; other extensions are ignored. Virtual
63 network devices are created as soon as networkd is started. If a netdev
64 with the specified name already exists, networkd will use that as-is
65 rather than create its own. Note that the settings of the pre-existing
66 netdev will not be changed by networkd.</para>
68 <para>The <filename>.netdev</filename> files are read from the files located in the
69 system network directory <filename>/usr/lib/systemd/network</filename>,
70 the volatile runtime network directory
71 <filename>/run/systemd/network</filename> and the local administration
72 network directory <filename>/etc/systemd/network</filename>.
73 All configuration files are collectively sorted and processed in lexical order,
74 regardless of the directories in which they live. However, files with
75 identical filenames replace each other. Files in
76 <filename>/etc</filename> have the highest priority, files in
77 <filename>/run</filename> take precedence over files with the same
78 name in <filename>/usr/lib</filename>. This can be used to override a
79 system-supplied configuration file with a local file if needed; a symlink in
80 <filename>/etc</filename> with the same name as a configuration file in
81 <filename>/usr/lib</filename>, pointing to <filename>/dev/null</filename>,
82 disables the configuration file entirely.</para>
87 <title>[Match] Section Options</title>
89 <para>A virtual network device is only created if the
90 <literal>[Match]</literal> section matches the current
91 environment, or if the section is empty. The following keys are accepted:</para>
93 <variablelist class='network-directives'>
95 <term><varname>Host=</varname></term>
97 <para>Matches against the hostname or machine ID of the
98 host. See <literal>ConditionHost=</literal> in
99 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
105 <term><varname>Virtualization=</varname></term>
107 <para>Checks whether the system is executed in a virtualized
108 environment and optionally test whether it is a specific
109 implementation. See <literal>ConditionVirtualization=</literal> in
110 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
116 <term><varname>KernelCommandLine=</varname></term>
118 <para>Checks whether a specific kernel command line option is
119 set (or if prefixed with the exclamation mark unset). See
120 <literal>ConditionKernelCommandLine=</literal> in
121 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
127 <term><varname>Architecture=</varname></term>
129 <para>Checks whether the system is running on a specific
130 architecture. See <literal>ConditionArchitecture=</literal> in
131 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
141 <title>[NetDev] Section Options</title>
143 <para>The <literal>[NetDev]</literal> section accepts the following
146 <variablelist class='network-directives'>
148 <term><varname>Description=</varname></term>
150 <para>A free-form description of the netdev.
155 <term><varname>Name=</varname></term>
157 <para>The interface name used when creating the
158 netdev. This option is compulsory.</para>
162 <term><varname>Kind=</varname></term>
164 <para>The netdev kind. Currently, <literal>bridge</literal>,
165 <literal>bond</literal>, <literal>vlan</literal>,
166 <literal>macvlan</literal>, <literal>vxlan</literal>,
167 <literal>ipip</literal>, <literal>gre</literal>,
168 <literal>sit</literal>, <literal>vti</literal>,
169 <literal>veth</literal>, <literal>tun</literal>,
170 <literal>tap</literal> and <literal>dummy</literal>
171 are supported. This option is compulsory.</para>
175 <term><varname>MTUBytes=</varname></term>
177 <para>The maximum transmission unit in bytes to
178 set for the device. The usual suffixes K, M, G,
179 are supported and are understood to the base of
184 <term><varname>MACAddress=</varname></term>
186 <para>The MAC address to use for the device.
187 If none is given, one is generated based on
188 the interface name and the
189 <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
197 <title>[VLAN] Section Options</title>
199 <para>The <literal>[VLAN]</literal> section only applies for netdevs of kind <literal>vlan</literal>,
200 and accepts the following key:</para>
202 <variablelist class='network-directives'>
204 <term><varname>Id=</varname></term>
206 <para>The VLAN ID to use. An integer in the range 0–4094.
207 This option is compulsory.</para>
215 <title>[MACVLAN] Section Options</title>
217 <para>The <literal>[MACVLAN]</literal> section only applies for netdevs of kind
218 <literal>macvlan</literal>, and accepts the following key:</para>
220 <variablelist class='network-directives'>
222 <term><varname>Mode=</varname></term>
224 <para>The MACVLAN mode to use. The supported options are
225 <literal>private</literal>, <literal>vepa</literal>,
226 <literal>bridge</literal> and <literal>passthru</literal>.
234 <title>[VXLAN] Section Options</title>
235 <para>The <literal>[VXLAN]</literal> section only applies for netdevs of kind
236 <literal>vxlan</literal>, and accepts the following key:</para>
238 <variablelist class='network-directives'>
240 <term><varname>Id=</varname></term>
242 <para>The VXLAN ID to use.</para>
246 <term><varname>Group=</varname></term>
248 <para>An assigned multicast group IP address.</para>
252 <term><varname>TOS=</varname></term>
254 <para>The Type Of Service byte value for a vxlan interface.</para>
258 <term><varname>TTL=</varname></term>
260 <para>A fixed Time To Live N on Virtual eXtensible Local Area Network packets.
261 N is a number in the range 1-255. 0 is a special value meaning that packets
262 inherit the TTL value.</para>
266 <term><varname>MacLearning=</varname></term>
268 <para>A boolean. When true, enables dynamic MAC learning
269 to discover remote MAC addresses.</para>
275 <title>[Tunnel] Section Options</title>
277 <para>The <literal>[Tunnel]</literal> section only applies for netdevs of kind
278 <literal>ipip</literal>, <literal>sit</literal>, <literal>gre</literal> and
279 <literal>vti</literal> and accepts the following keys:</para>
281 <variablelist class='network-directives'>
283 <term><varname>Local=</varname></term>
285 <para>A static local address for tunneled packets.
286 It must be an address on another interface of this host.</para>
290 <term><varname>Remote=</varname></term>
292 <para>The remote endpoint of the tunnel.</para>
296 <term><varname>TOS=</varname></term>
298 <para>The Type Of Service byte value for a tunnel interface.
299 For details about the TOS see the
300 <ulink url="http://tools.ietf.org/html/rfc1349">
301 Type of Service in the Internet Protocol Suite
307 <term><varname>TTL=</varname></term>
309 <para>A fixed Time To Live N on tunneled packets.
310 N is a number in the range 1-255. 0 is a special value meaning that packets
311 inherit the TTL value. The default value for IPv4 tunnels is: inherit.
312 The default value for IPv6 tunnels is: 64.</para>
316 <term><varname>DiscoverPathMTU=</varname></term>
318 <para>A boolean. When true, enables Path MTU Discovery on the tunnel.</para>
324 <title>[Peer] Section Options</title>
326 <para>The <literal>[Peer]</literal> section only applies for netdevs of kind <literal>veth</literal>
327 and accepts the following key:</para>
329 <variablelist class='network-directives'>
331 <term><varname>Name=</varname></term>
333 <para>The interface name used when creating the netdev.
334 This option is compulsory.</para>
338 <term><varname>MACAddress=</varname></term>
340 <para>The peer MACAddress, if not set it is generated in the same
341 way as the MAC address of the main interface.</para>
347 <title>[Tun] Section Options</title>
349 <para>The <literal>[Tun]</literal> section only applies for netdevs of kind
350 <literal>tun</literal>, and accepts the following keys:</para>
352 <variablelist class='network-directives'>
354 <term><varname>OneQueue=</varname></term>
355 <listitem><para>Takes a boolean argument. Configures whether
356 all packets are queued at the device (enabled), or a fixed number
357 of packets are queued at the device and the rest at the
358 <literal>qdisc</literal>. Defaults to <literal>no</literal>.</para>
362 <term><varname>MultiQueue=</varname></term>
363 <listitem><para>Takes a boolean argument. Configures whether to
364 use multiple file descriptors (queues) to parallelize packets
365 sending and receiving. Defaults to <literal>no</literal>.</para>
369 <term><varname>PacketInfo=</varname></term>
370 <listitem><para>Takes a boolean argument. Configures whether packets
371 should be prepened with four extra bytes (two flag bytes and two
372 protocol bytes). If disabled it indicates that the packets will be
373 pure IP packets. Defaults to <literal>no</literal>.</para>
377 <term><varname>User=</varname></term>
378 <listitem><para>User to grant access to the <filename>/dev/net/tun</filename>
383 <term><varname>Group=</varname></term>
384 <listitem><para>Group to grant access to the <filename>/dev/net/tun</filename>
394 <title>[Tap] Section Options</title>
396 <para>The <literal>[Tap]</literal> section only applies for netdevs of kind
397 <literal>tap</literal>, and accepts the same keys as the
398 <literal>[Tun]</literal> section.</para>
402 <title>[Bond] Section Options</title>
404 <para>The <literal>[Bond]</literal> section accepts the following
407 <variablelist class='network-directives'>
409 <term><varname>Mode=</varname></term>
411 <para>Specifies one of the bonding policies. The default is
412 <literal>balance-rr</literal> (round robin). Possible values are
413 <literal>balance-rr</literal>,
414 <literal>active-backup</literal>,
415 <literal>balance-xor</literal>,
416 <literal>broadcast</literal>,
417 <literal>802.3ad</literal>,
418 <literal>balance-tlb</literal>, and
419 <literal>balance-alb</literal>.
425 <term><varname>TransmitHashPolicy=</varname></term>
427 <para>Selects the transmit hash policy to use for slave selection in
428 balance-xor, 802.3ad, and tlb modes. Possible values are
429 <literal>layer2</literal>,
430 <literal>layer3+4</literal>,
431 <literal>layer2+3</literal>,
432 <literal>encap2+3</literal>,
433 <literal>802.3ad</literal>, and
434 <literal>encap3+4</literal>.
440 <term><varname>LACPTransmitRate=</varname></term>
442 <para>Specifies the rate with which link partner
443 transmits Link Aggregation Control Protocol Data Unit packets
444 in 802.3ad mode. Possible values are
445 <literal>slow</literal>, which requests partner to transmit LACPDUs every 30 seconds, and
446 <literal>fast</literal>, which requests partner to transmit LACPDUs every second.
447 The default value is <literal>slow</literal>.</para>
452 <term><varname>MIIMonitorSec=</varname></term>
454 <para>Specifies the frequency that Media Independent Interface link
455 monitoring will occur. A value of zero disables MII link monitoring.
456 This values is rounded down to the nearest millisecond. The default
462 <term><varname>UpDelaySec=</varname></term>
464 <para>Specifies the delay before a link is enabled after a link up
465 status has been detected. This value is rounded down to a multiple of
466 MIIMonitorSec. The default value is 0.</para>
471 <term><varname>DownDelaySec=</varname></term>
473 <para>Specifies the delay before a link is disabled after a link down
474 status has been detected. This value is rounded down to a multiple of
475 MIIMonitorSec. The default value is 0.</para>
483 <title>Example</title>
485 <title>/etc/systemd/network/bridge.netdev</title>
487 <programlisting>[NetDev]
489 Kind=bridge</programlisting>
493 <title>/etc/systemd/network/vlan1.netdev</title>
495 <programlisting>[Match]
503 Id=1</programlisting>
506 <title>/etc/systemd/network/ipip.netdev</title>
507 <programlisting>[NetDev]
513 Local=192.168.223.238
514 Remote=192.169.224.239
515 TTL=64</programlisting>
518 <title>/etc/systemd/network/tap.netdev</title>
519 <programlisting>[NetDev]
525 PacketInfo=true</programlisting> </example>
528 <title>/etc/systemd/network/sit.netdev</title>
529 <programlisting>[NetDev]
536 Remote=10.65.223.239</programlisting>
540 <title>/etc/systemd/network/gre.netdev</title>
541 <programlisting>[NetDev]
548 Remote=10.65.223.239</programlisting>
552 <title>/etc/systemd/network/vti.netdev</title>
554 <programlisting>[NetDev]
561 Remote=10.65.223.239</programlisting>
565 <title>/etc/systemd/network/veth.netdev</title>
566 <programlisting>[NetDev]
571 Name=veth-peer</programlisting>
575 <title>/etc/systemd/network/dummy.netdev</title>
576 <programlisting>[NetDev]
579 MACAddress=12:34:56:78:9a:bc</programlisting>
584 <title>See Also</title>
586 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
587 <citerefentry><refentrytitle>systemd-networkd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
588 <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>