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.
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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>LinkLocal=</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>LLMNR=</varname></term>
261 <para>A boolean or <literal>resolve</literal>. When true, enables
262 Link-Local Multicast Name Resolution on the link, when set to
263 <literal>resolve</literal> only resolution is enabled, but not
264 announcement. Defaults to true.</para>
268 <term><varname>LLDP=</varname></term>
270 <para>A boolean. When true, enables LLDP link receive support.
275 <term><varname>Address=</varname></term>
277 <para>A static IPv4 or IPv6 address and its prefix length,
278 separated by a <literal>/</literal> character. Specify
279 this key more than once to configure several addresses.
280 The format of the address must be as described in
281 <citerefentry><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
282 This is a short-hand for an [Address] section only
283 containing an Address key (see below). This option may be
284 specified more than once.
287 <para>If the specified address is 0.0.0.0 (for IPv4) or
288 [::] (for IPv6), a new address range of the requested size
289 is automatically allocated from a system-wide pool of
290 unused ranges. The allocated range is checked against all
291 current network interfaces and all known network
292 configuration files to avoid address range conflicts. The
293 default system-wide pool consists of 192.168.0.0/16,
294 172.16.0.0/12 and 10.0.0.0/8 for IPv4, and fc00::/7 for
295 IPv6. This functionality is useful to manage a large
296 number of dynamically created network interfaces with the
297 same network configuration and automatic address range
303 <term><varname>Gateway=</varname></term>
305 <para>The gateway address, which must be in the format
307 <citerefentry><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
308 This is a short-hand for a [Route] section only containing
309 a Gateway key. This option may be specified more than
314 <term><varname>DNS=</varname></term>
316 <para>A DNS server address, which must be in the format
318 <citerefentry><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
319 This option may be specified more than once.</para>
323 <term><varname>Domains=</varname></term>
325 <para>The domains used for DNS resolution over this link.</para>
329 <term><varname>NTP=</varname></term>
331 <para>An NTP server address. This option may be specified more than once.</para>
335 <term><varname>IPForward=</varname></term>
336 <listitem><para>Configures IP forwarding for the network
337 interface. If enabled incoming packets on the network
338 interface will be forwarded to other interfaces according to
339 the routing table. Takes either a boolean argument, or the
340 values <literal>ipv4</literal> or <literal>ipv6</literal>,
341 which only enables IP forwarding for the specified address
342 family.</para></listitem>
345 <term><varname>IPMasquerade=</varname></term>
346 <listitem><para>Configures IP masquerading for the network
347 interface. If enabled packets forwarded from the network
348 interface will be appear as coming from the local host.
349 Takes a boolean argument. Implies
350 <varname>IPForward=yes</varname>.</para></listitem>
353 <term><varname>Bridge=</varname></term>
355 <para>The name of the bridge to add the link to.</para>
359 <term><varname>Bond=</varname></term>
361 <para>The name of the bond to add the link to.</para>
365 <term><varname>VLAN=</varname></term>
367 <para>The name of a VLAN to create on the link. This
368 option may be specified more than once.</para>
372 <term><varname>MACVLAN=</varname></term>
374 <para>The name of a MACVLAN to create on the link. This
375 option may be specified more than once.</para>
379 <term><varname>VXLAN=</varname></term>
381 <para>The name of a VXLAN to create on the link. This
382 option may be specified more than once.</para>
386 <term><varname>Tunnel=</varname></term>
388 <para>The name of a Tunnel to create on the link. This
389 option may be specified more than once.</para>
397 <title>[Address] Section Options</title>
399 <para>An <literal>[Address]</literal> section accepts the
400 following keys. Specify several <literal>[Address]</literal>
401 sections to configure several addresses.</para>
403 <variablelist class='network-directives'>
405 <term><varname>Address=</varname></term>
407 <para>As in the <literal>[Network]</literal> section. This
408 key is mandatory.</para>
412 <term><varname>Peer=</varname></term>
414 <para>The peer address in a point-to-point connection.
415 Accepts the same format as the <literal>Address</literal>
420 <term><varname>Broadcast=</varname></term>
422 <para>The broadcast address, which must be in the format
424 <citerefentry><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
425 This key only applies to IPv4 addresses. If it is not
426 given, it is derived from the <literal>Address</literal>
431 <term><varname>Label=</varname></term>
433 <para>An address label.</para>
440 <title>[Route] Section Options</title>
441 <para>The <literal>[Route]</literal> section accepts the
442 following keys. Specify several <literal>[Route]</literal>
443 sections to configure several routes.</para>
445 <variablelist class='network-directives'>
447 <term><varname>Gateway=</varname></term>
449 <para>As in the <literal>[Network]</literal> section.</para>
453 <term><varname>Destination=</varname></term>
455 <para>The destination prefix of the route. Possibly
456 followed by a slash and the prefixlength. If omitted, a
457 full-length host route is assumed.</para>
461 <term><varname>Source=</varname></term>
463 <para>The source prefix of the route. Possibly followed by
464 a slash and the prefixlength. If omitted, a full-length
465 host route is assumed.</para>
469 <term><varname>Metric=</varname></term>
471 <para>The metric of the route. An unsigned integer</para>
475 <term><varname>Scope=</varname></term>
477 <para>The scope of the route. One of the values <literal>global</literal>,
478 <literal>link</literal> or <literal>host</literal>. Defaults to
479 <literal>global</literal>.</para>
486 <title>[DHCP] Section Options</title>
487 <para>The <literal>[DHCP]</literal> section accepts the following keys:</para>
489 <variablelist class='network-directives'>
491 <term><varname>UseDNS=</varname></term>
493 <para>When true (the default), the DNS servers received
494 from the DHCP server will be used and take precedence over
495 any statically configured ones.</para>
499 <term><varname>UseMTU=</varname></term>
501 <para>When true, the interface maximum transmission unit
502 from the DHCP server will be used on the current link.
503 Defaults to false.</para>
507 <term><varname>SendHostname=</varname></term>
509 <para>When true (the default), the machine's hostname will be sent to the DHCP
514 <term><varname>UseHostname=</varname></term>
516 <para>When true (the default), the hostname received from
517 the DHCP server will be used as the transient
522 <term><varname>UseDomains=</varname></term>
524 <para>When true (not the default), the domain name
525 received from the DHCP server will be used for DNS
526 resolution over this link.</para>
530 <term><varname>UseRoutes=</varname></term>
532 <para>When true (the default), the static routes will be
533 requested from the DHCP server and added to the routing
534 table with metric of 1024.</para>
538 <term><varname>CriticalConnection=</varname></term>
540 <para>When true, the connection will never be torn down
541 even if the DHCP lease expires. This is contrary to the
542 DHCP specification, but may be the best choice if, say,
543 the root filesystem relies on this connection. Defaults to
548 <term><varname>VendorClassIdentifier=</varname></term>
550 <para>The vendor class identifier used to identify vendor
551 type and configuration.</para>
555 <term><varname>RequestBroadcast=</varname></term>
557 <para>Request the server to use broadcast messages before
558 the IP address has been configured. This is necessary for
559 devices that cannot receive RAW packets, or that cannot
560 receive packets at all before an IP address has been
561 configured. On the other hand, this must not be enabled on
562 networks where broadcasts are filtered out.</para>
566 <term><varname>RouteMetric=</varname></term>
568 <para>Set the routing metric for routes specified by the
577 <title>[Bridge] Section Options</title>
578 <para>The <literal>[Bridge]</literal> section accepts the
579 following keys.</para>
580 <variablelist class='network-directives'>
582 <term><varname>Cost=</varname></term>
584 <para>Each port in a bridge may have different speed. Cost
585 is used to decide which link to use. Faster interfaces
586 should have lower costs</para>
593 <title>[BridgeFDB] Section Options</title>
594 <para>The <literal>[BridgeFDB]</literal> section manages the
595 forwarding database table of a port and accepts the following
596 keys. Specify several <literal>[BridgeFDB]</literal> sections to
597 configure several static MAC table entries.</para>
599 <variablelist class='network-directives'>
601 <term><varname>MACAddress=</varname></term>
603 <para>As in the <literal>[Network]</literal> section. This
604 key is mandatory.</para>
608 <term><varname>VLANId=</varname></term>
610 <para>The VLAN Id for the new static MAC table entry. If
611 omitted, no VLAN Id info is appended to the new static MAC
619 <title>Example</title>
621 <title>/etc/systemd/network/50-static.network</title>
623 <programlisting>[Match]
627 Address=192.168.0.15/24
628 Gateway=192.168.0.1</programlisting>
632 <title>/etc/systemd/network/80-dhcp.network</title>
634 <programlisting>[Match]
638 DHCP=both</programlisting>
642 <title>/etc/systemd/network/bridge-static.network</title>
644 <programlisting>[Match]
648 Address=192.168.0.15/24
650 DNS=192.168.0.1</programlisting>
654 <title>/etc/systemd/network/bridge-slave-interface.network</title>
656 <programlisting>[Match]
660 Bridge=bridge0</programlisting>
663 <title>/etc/systemd/network/ipip.network</title>
665 <programlisting>[Match]
669 Tunnel=ipip-tun</programlisting>
673 <title>/etc/systemd/network/sit.network</title>
675 <programlisting>[Match]
679 Tunnel=sit-tun</programlisting>
683 <title>/etc/systemd/network/gre.network</title>
685 <programlisting>[Match]
689 Tunnel=gre-tun</programlisting>
693 <title>/etc/systemd/network/vti.network</title>
695 <programlisting>[Match]
699 Tunnel=vti-tun</programlisting>
704 <title>See Also</title>
706 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
707 <citerefentry><refentrytitle>systemd-networkd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
708 <citerefentry><refentrytitle>systemd.link</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
709 <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>