1 <?xml version='1.0'?> <!--*-nxml-*-->
2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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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
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24 <refentry id="systemd.network" 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.network</refentrytitle>
42 <manvolnum>5</manvolnum>
46 <refname>systemd.network</refname>
47 <refpurpose>Network configuration</refpurpose>
51 <para><filename><replaceable>network</replaceable>.network</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>Network files must have the extension
62 <filename>.network</filename>; other extensions are ignored.
63 Networks are applied to links whenever the links appear.</para>
65 <para>The <filename>.network</filename> files are read from the
66 files located in the system network directory
67 <filename>/usr/lib/systemd/network</filename>, the volatile
68 runtime network directory
69 <filename>/run/systemd/network</filename> and the local
70 administration network directory
71 <filename>/etc/systemd/network</filename>. All configuration files
72 are collectively sorted and processed in lexical order, regardless
73 of the directories in which they live. However, files with
74 identical filenames replace each other. Files in
75 <filename>/etc</filename> have the highest priority, files in
76 <filename>/run</filename> take precedence over files with the same
77 name in <filename>/usr/lib</filename>. This can be used to
78 override a system-supplied configuration file with a local file if
79 needed; a symlink in <filename>/etc</filename> with the same name
80 as a configuration file in <filename>/usr/lib</filename>, pointing
81 to <filename>/dev/null</filename>, disables the configuration file
87 <title>[Match] Section Options</title>
89 <para>The network file contains a <literal>[Match]</literal>
90 section, which determines if a given network file may be applied
91 to a given device; and a <literal>[Network]</literal> section
92 specifying how the device should be configured. The first (in
93 lexical order) of the network files that matches a given device
96 <para>A network file is said to match a device if each of the
97 entries in the <literal>[Match]</literal> section matches, or if
98 the section is empty. The following keys are accepted:</para>
100 <variablelist class='network-directives'>
102 <term><varname>MACAddress=</varname></term>
104 <para>The hardware address.</para>
108 <term><varname>Path=</varname></term>
110 <para>A whitespace-separated list of shell-style globs
111 matching the persistent path, as exposed by the udev
112 property <literal>ID_PATH</literal>.</para>
116 <term><varname>Driver=</varname></term>
118 <para>A whitespace-separated list of shell-style globs
119 matching the driver currently bound to the device, as
120 exposed by the udev property <literal>DRIVER</literal>
121 of its parent device, or if that is not set the driver
122 as exposed by <literal>ethtool -i</literal> of the
123 device itself.</para>
127 <term><varname>Type=</varname></term>
129 <para>A whitespace-separated list of shell-style globs
130 matching the device type, as exposed by the udev property
131 <literal>DEVTYPE</literal>.</para>
135 <term><varname>Name=</varname></term>
137 <para>A whitespace-separated list of shell-style globs
138 matching the device name, as exposed by the udev property
139 <literal>INTERFACE</literal>.</para>
143 <term><varname>Host=</varname></term>
145 <para>Matches against the hostname or machine ID of the
146 host. See <literal>ConditionHost=</literal> in
147 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
153 <term><varname>Virtualization=</varname></term>
155 <para>Checks whether the system is executed in a virtualized
156 environment and optionally test whether it is a specific
157 implementation. See <literal>ConditionVirtualization=</literal> in
158 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
164 <term><varname>KernelCommandLine=</varname></term>
166 <para>Checks whether a specific kernel command line option is
167 set (or if prefixed with the exclamation mark unset). See
168 <literal>ConditionKernelCommandLine=</literal> in
169 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
175 <term><varname>Architecture=</varname></term>
177 <para>Checks whether the system is running on a specific
178 architecture. See <literal>ConditionArchitecture=</literal> in
179 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
189 <title>[Link] Section Options</title>
191 <para> The <literal>[Link]</literal> section accepts the following keys:</para>
193 <variablelist class='network-directives'>
195 <term><varname>MACAddress=</varname></term>
197 <para>The hardware address.</para>
201 <term><varname>MTUBytes=</varname></term>
203 <para>The maximum transmission unit in bytes to set for the
204 device. The usual suffixes K, M, G, are supported and are
205 understood to the base of 1024.</para>
212 <title>[Network] Section Options</title>
214 <para>The <literal>[Network]</literal> section accepts the following keys:</para>
216 <variablelist class='network-directives'>
218 <term><varname>Description=</varname></term>
220 <para>A description of the device. This is only used for
221 presentation purposes.</para>
225 <term><varname>DHCP=</varname></term>
227 <para>Enables DHCPv4 and/or DHCPv6 support. Accepts
228 <literal>yes</literal>, <literal>no</literal>,
229 <literal>ipv4</literal>, or <literal>ipv6</literal>.</para>
233 <term><varname>DHCPServer=</varname></term>
235 <para>A boolean. Enables a basic DHCPv4 server on the
236 device. Mostly useful for handing out leases to container
241 <term><varname>LinkLocalAddressing=</varname></term>
243 <para>Enables link-local address autoconfiguration. Accepts
244 <literal>yes</literal>, <literal>no</literal>,
245 <literal>ipv4</literal>, or <literal>ipv6</literal>. Defaults to
246 <literal>ipv6</literal>.</para>
250 <term><varname>IPv4LLRoute=</varname></term>
252 <para>A boolean. When true, sets up the route needed for
253 non-IPv4LL hosts to communicate with IPv4LL-only hosts. Defaults
259 <term><varname>IPv6Token=</varname></term>
261 <para>An IPv6 address with the top 64 bits unset. When set, indicates the
262 64 bits interface part of SLAAC IPv6 addresses for this link. By default
263 it is autogenerated.</para>
267 <term><varname>LLMNR=</varname></term>
269 <para>A boolean or <literal>resolve</literal>. When true, enables
270 Link-Local Multicast Name Resolution on the link, when set to
271 <literal>resolve</literal> only resolution is enabled, but not
272 announcement. Defaults to true.</para>
276 <term><varname>LLDP=</varname></term>
278 <para>A boolean. When true, enables LLDP link receive support.
283 <term><varname>Address=</varname></term>
285 <para>A static IPv4 or IPv6 address and its prefix length,
286 separated by a <literal>/</literal> character. Specify
287 this key more than once to configure several addresses.
288 The format of the address must be as described in
289 <citerefentry><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
290 This is a short-hand for an [Address] section only
291 containing an Address key (see below). This option may be
292 specified more than once.
295 <para>If the specified address is 0.0.0.0 (for IPv4) or
296 [::] (for IPv6), a new address range of the requested size
297 is automatically allocated from a system-wide pool of
298 unused ranges. The allocated range is checked against all
299 current network interfaces and all known network
300 configuration files to avoid address range conflicts. The
301 default system-wide pool consists of 192.168.0.0/16,
302 172.16.0.0/12 and 10.0.0.0/8 for IPv4, and fc00::/7 for
303 IPv6. This functionality is useful to manage a large
304 number of dynamically created network interfaces with the
305 same network configuration and automatic address range
311 <term><varname>Gateway=</varname></term>
313 <para>The gateway address, which must be in the format
315 <citerefentry><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
316 This is a short-hand for a [Route] section only containing
317 a Gateway key. This option may be specified more than
322 <term><varname>DNS=</varname></term>
324 <para>A DNS server address, which must be in the format
326 <citerefentry><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
327 This option may be specified more than once.</para>
331 <term><varname>Domains=</varname></term>
333 <para>The domains used for DNS resolution over this link.</para>
337 <term><varname>NTP=</varname></term>
339 <para>An NTP server address. This option may be specified more than once.</para>
343 <term><varname>IPForward=</varname></term>
344 <listitem><para>Configures IP forwarding for the network
345 interface. If enabled incoming packets on the network
346 interface will be forwarded to other interfaces according to
347 the routing table. Takes either a boolean argument, or the
348 values <literal>ipv4</literal> or <literal>ipv6</literal>,
349 which only enables IP forwarding for the specified address
350 family.</para></listitem>
353 <term><varname>IPMasquerade=</varname></term>
354 <listitem><para>Configures IP masquerading for the network
355 interface. If enabled packets forwarded from the network
356 interface will be appear as coming from the local host.
357 Takes a boolean argument. Implies
358 <varname>IPForward=yes</varname>.</para></listitem>
361 <term><varname>Bridge=</varname></term>
363 <para>The name of the bridge to add the link to.</para>
367 <term><varname>Bond=</varname></term>
369 <para>The name of the bond to add the link to.</para>
373 <term><varname>VLAN=</varname></term>
375 <para>The name of a VLAN to create on the link. This
376 option may be specified more than once.</para>
380 <term><varname>MACVLAN=</varname></term>
382 <para>The name of a MACVLAN to create on the link. This
383 option may be specified more than once.</para>
387 <term><varname>VXLAN=</varname></term>
389 <para>The name of a VXLAN to create on the link. This
390 option may be specified more than once.</para>
394 <term><varname>Tunnel=</varname></term>
396 <para>The name of a Tunnel to create on the link. This
397 option may be specified more than once.</para>
405 <title>[Address] Section Options</title>
407 <para>An <literal>[Address]</literal> section accepts the
408 following keys. Specify several <literal>[Address]</literal>
409 sections to configure several addresses.</para>
411 <variablelist class='network-directives'>
413 <term><varname>Address=</varname></term>
415 <para>As in the <literal>[Network]</literal> section. This
416 key is mandatory.</para>
420 <term><varname>Peer=</varname></term>
422 <para>The peer address in a point-to-point connection.
423 Accepts the same format as the <literal>Address</literal>
428 <term><varname>Broadcast=</varname></term>
430 <para>The broadcast address, which must be in the format
432 <citerefentry><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
433 This key only applies to IPv4 addresses. If it is not
434 given, it is derived from the <literal>Address</literal>
439 <term><varname>Label=</varname></term>
441 <para>An address label.</para>
448 <title>[Route] Section Options</title>
449 <para>The <literal>[Route]</literal> section accepts the
450 following keys. Specify several <literal>[Route]</literal>
451 sections to configure several routes.</para>
453 <variablelist class='network-directives'>
455 <term><varname>Gateway=</varname></term>
457 <para>As in the <literal>[Network]</literal> section.</para>
461 <term><varname>Destination=</varname></term>
463 <para>The destination prefix of the route. Possibly
464 followed by a slash and the prefixlength. If omitted, a
465 full-length host route is assumed.</para>
469 <term><varname>Source=</varname></term>
471 <para>The source prefix of the route. Possibly followed by
472 a slash and the prefixlength. If omitted, a full-length
473 host route is assumed.</para>
477 <term><varname>Metric=</varname></term>
479 <para>The metric of the route. An unsigned integer</para>
483 <term><varname>Scope=</varname></term>
485 <para>The scope of the route. One of the values <literal>global</literal>,
486 <literal>link</literal> or <literal>host</literal>. Defaults to
487 <literal>global</literal>.</para>
494 <title>[DHCP] Section Options</title>
495 <para>The <literal>[DHCP]</literal> section accepts the following keys:</para>
497 <variablelist class='network-directives'>
499 <term><varname>UseDNS=</varname></term>
501 <para>When true (the default), the DNS servers received
502 from the DHCP server will be used and take precedence over
503 any statically configured ones.</para>
507 <term><varname>UseMTU=</varname></term>
509 <para>When true, the interface maximum transmission unit
510 from the DHCP server will be used on the current link.
511 Defaults to false.</para>
515 <term><varname>SendHostname=</varname></term>
517 <para>When true (the default), the machine's hostname will be sent to the DHCP
522 <term><varname>UseHostname=</varname></term>
524 <para>When true (the default), the hostname received from
525 the DHCP server will be used as the transient
530 <term><varname>UseDomains=</varname></term>
532 <para>When true (not the default), the domain name
533 received from the DHCP server will be used for DNS
534 resolution over this link.</para>
538 <term><varname>UseRoutes=</varname></term>
540 <para>When true (the default), the static routes will be
541 requested from the DHCP server and added to the routing
542 table with metric of 1024.</para>
546 <term><varname>CriticalConnection=</varname></term>
548 <para>When true, the connection will never be torn down
549 even if the DHCP lease expires. This is contrary to the
550 DHCP specification, but may be the best choice if, say,
551 the root filesystem relies on this connection. Defaults to
556 <term><varname>VendorClassIdentifier=</varname></term>
558 <para>The vendor class identifier used to identify vendor
559 type and configuration.</para>
563 <term><varname>RequestBroadcast=</varname></term>
565 <para>Request the server to use broadcast messages before
566 the IP address has been configured. This is necessary for
567 devices that cannot receive RAW packets, or that cannot
568 receive packets at all before an IP address has been
569 configured. On the other hand, this must not be enabled on
570 networks where broadcasts are filtered out.</para>
574 <term><varname>RouteMetric=</varname></term>
576 <para>Set the routing metric for routes specified by the
585 <title>[Bridge] Section Options</title>
586 <para>The <literal>[Bridge]</literal> section accepts the
587 following keys.</para>
588 <variablelist class='network-directives'>
590 <term><varname>Cost=</varname></term>
592 <para>Each port in a bridge may have different speed. Cost
593 is used to decide which link to use. Faster interfaces
594 should have lower costs</para>
601 <title>[BridgeFDB] Section Options</title>
602 <para>The <literal>[BridgeFDB]</literal> section manages the
603 forwarding database table of a port and accepts the following
604 keys. Specify several <literal>[BridgeFDB]</literal> sections to
605 configure several static MAC table entries.</para>
607 <variablelist class='network-directives'>
609 <term><varname>MACAddress=</varname></term>
611 <para>As in the <literal>[Network]</literal> section. This
612 key is mandatory.</para>
616 <term><varname>VLANId=</varname></term>
618 <para>The VLAN Id for the new static MAC table entry. If
619 omitted, no VLAN Id info is appended to the new static MAC
627 <title>Example</title>
629 <title>/etc/systemd/network/50-static.network</title>
631 <programlisting>[Match]
635 Address=192.168.0.15/24
636 Gateway=192.168.0.1</programlisting>
640 <title>/etc/systemd/network/80-dhcp.network</title>
642 <programlisting>[Match]
646 DHCP=both</programlisting>
650 <title>/etc/systemd/network/bridge-static.network</title>
652 <programlisting>[Match]
656 Address=192.168.0.15/24
658 DNS=192.168.0.1</programlisting>
662 <title>/etc/systemd/network/bridge-slave-interface.network</title>
664 <programlisting>[Match]
668 Bridge=bridge0</programlisting>
671 <title>/etc/systemd/network/ipip.network</title>
673 <programlisting>[Match]
677 Tunnel=ipip-tun</programlisting>
681 <title>/etc/systemd/network/sit.network</title>
683 <programlisting>[Match]
687 Tunnel=sit-tun</programlisting>
691 <title>/etc/systemd/network/gre.network</title>
693 <programlisting>[Match]
697 Tunnel=gre-tun</programlisting>
701 <title>/etc/systemd/network/vti.network</title>
703 <programlisting>[Match]
707 Tunnel=vti-tun</programlisting>
712 <title>See Also</title>
714 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
715 <citerefentry><refentrytitle>systemd-networkd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
716 <citerefentry><refentrytitle>systemd.link</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
717 <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>