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514094f9 1<?xml version='1.0'?>
3a54a157 2<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
12b42c76 3 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
0307f791 4<!-- SPDX-License-Identifier: LGPL-2.1+ -->
eac684ef 5
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6<refentry id="systemd.network" conditional='ENABLE_NETWORKD'
7 xmlns:xi="http://www.w3.org/2001/XInclude">
eac684ef 8
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9 <refentryinfo>
10 <title>systemd.network</title>
11 <productname>systemd</productname>
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12 </refentryinfo>
13
14 <refmeta>
15 <refentrytitle>systemd.network</refentrytitle>
16 <manvolnum>5</manvolnum>
17 </refmeta>
18
19 <refnamediv>
20 <refname>systemd.network</refname>
21 <refpurpose>Network configuration</refpurpose>
22 </refnamediv>
23
24 <refsynopsisdiv>
25 <para><filename><replaceable>network</replaceable>.network</filename></para>
26 </refsynopsisdiv>
27
28 <refsect1>
29 <title>Description</title>
30
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31 <para>A plain ini-style text file that encodes network configuration for matching network interfaces,
32 used by
798d3a52 33 <citerefentry><refentrytitle>systemd-networkd</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
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34 See <citerefentry><refentrytitle>systemd.syntax</refentrytitle><manvolnum>5</manvolnum></citerefentry>
35 for a general description of the syntax.</para>
798d3a52 36
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37 <para>The main network file must have the extension <filename>.network</filename>; other
38 extensions are ignored. Networks are applied to links whenever the links appear.</para>
39
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40 <para>The <filename>.network</filename> files are read from the files located in the system network
41 directories <filename>/usr/lib/systemd/network</filename> and
42 <filename>/usr/local/lib/systemd/network</filename>, the volatile runtime network directory
43 <filename>/run/systemd/network</filename> and the local administration network directory
44 <filename>/etc/systemd/network</filename>. All configuration files are collectively sorted and processed
45 in lexical order, regardless of the directories in which they live. However, files with identical
46 filenames replace each other. Files in <filename>/etc</filename> have the highest priority, files in
47 <filename>/run</filename> take precedence over files with the same name under
48 <filename>/usr</filename>. This can be used to override a system-supplied configuration file with a local
49 file if needed. As a special case, an empty file (file size 0) or symlink with the same name pointing to
50 <filename>/dev/null</filename> disables the configuration file entirely (it is "masked").</para>
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51
52 <para>Along with the network file <filename>foo.network</filename>, a "drop-in" directory
53 <filename>foo.network.d/</filename> may exist. All files with the suffix
54 <literal>.conf</literal> from this directory will be parsed after the file itself is
55 parsed. This is useful to alter or add configuration settings, without having to modify the main
56 configuration file. Each drop-in file must have appropriate section headers.</para>
57
58 <para>In addition to <filename>/etc/systemd/network</filename>, drop-in <literal>.d</literal>
59 directories can be placed in <filename>/usr/lib/systemd/network</filename> or
60 <filename>/run/systemd/network</filename> directories. Drop-in files in
61 <filename>/etc</filename> take precedence over those in <filename>/run</filename> which in turn
62 take precedence over those in <filename>/usr/lib</filename>. Drop-in files under any of these
b1e91af8 63 directories take precedence over the main network file wherever located.</para>
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64
65 <para>Note that an interface without any static IPv6 addresses configured, and neither DHCPv6
66 nor IPv6LL enabled, shall be considered to have no IPv6 support. IPv6 will be automatically
67 disabled for that interface by writing "1" to
68 <filename>/proc/sys/net/ipv6/conf/<replaceable>ifname</replaceable>/disable_ipv6</filename>.
82ecb4c3 69 </para>
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70 </refsect1>
71
72 <refsect1>
73 <title>[Match] Section Options</title>
74
75 <para>The network file contains a <literal>[Match]</literal>
76 section, which determines if a given network file may be applied
77 to a given device; and a <literal>[Network]</literal> section
78 specifying how the device should be configured. The first (in
79 lexical order) of the network files that matches a given device
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80 is applied, all later files are ignored, even if they match as
81 well.</para>
798d3a52 82
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83 <para>A network file is said to match a network interface if all matches specified by the
84 <literal>[Match]</literal> section are satisfied. When a network file does not contain valid
85 settings in <literal>[Match]</literal> section, then the file will match all interfaces and
86 <command>systemd-networkd</command> warns about that. Hint: to avoid the warning and to make it
87 clear that all interfaces shall be matched, add the following:
88 <programlisting>Name=*</programlisting>
89 The following keys are accepted:</para>
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90
91 <variablelist class='network-directives'>
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92 <xi:include href="systemd.link.xml" xpointer="mac-address" />
93 <xi:include href="systemd.link.xml" xpointer="permanent-mac-address" />
94 <xi:include href="systemd.link.xml" xpointer="path" />
95 <xi:include href="systemd.link.xml" xpointer="driver" />
96 <xi:include href="systemd.link.xml" xpointer="type" />
97 <xi:include href="systemd.link.xml" xpointer="property" />
9310bf4b 98
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99 <varlistentry>
100 <term><varname>Name=</varname></term>
101 <listitem>
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102 <para>A whitespace-separated list of shell-style globs matching the device name, as exposed
103 by the udev property <literal>INTERFACE</literal>, or device's alternative names. If the
104 list is prefixed with a "!", the test is inverted.</para>
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105 </listitem>
106 </varlistentry>
44005bfb 107
78404d22 108 <varlistentry>
1bcefad9 109 <term><varname>WLANInterfaceType=</varname></term>
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110 <listitem>
111 <para>A whitespace-separated list of wireless network type. Supported values are
112 <literal>ad-hoc</literal>, <literal>station</literal>, <literal>ap</literal>,
113 <literal>ap-vlan</literal>, <literal>wds</literal>, <literal>monitor</literal>,
114 <literal>mesh-point</literal>, <literal>p2p-client</literal>, <literal>p2p-go</literal>,
115 <literal>p2p-device</literal>, <literal>ocb</literal>, and <literal>nan</literal>. If the
116 list is prefixed with a "!", the test is inverted.
117 </para>
118 </listitem>
119 </varlistentry>
d9b20454 120
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121 <varlistentry>
122 <term><varname>SSID=</varname></term>
123 <listitem>
124 <para>A whitespace-separated list of shell-style globs matching the SSID of the currently
125 connected wireless LAN. If the list is prefixed with a "!", the test is inverted.
126 </para>
127 </listitem>
128 </varlistentry>
d9b20454 129
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130 <varlistentry>
131 <term><varname>BSSID=</varname></term>
132 <listitem>
133 <para>A whitespace-separated list of hardware address of the currently connected wireless
134 LAN. Use full colon-, hyphen- or dot-delimited hexadecimal. See the example in
135 <varname>MACAddress=</varname>. This option may appear more than one, in which case the
136 lists are merged. If the empty string is assigned to this option, the list of BSSID defined
137 prior to this is reset.</para>
138 </listitem>
139 </varlistentry>
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140
141 <xi:include href="systemd.link.xml" xpointer="host" />
142 <xi:include href="systemd.link.xml" xpointer="virtualization" />
143 <xi:include href="systemd.link.xml" xpointer="kernel-command-line" />
144 <xi:include href="systemd.link.xml" xpointer="kernel-version" />
145 <xi:include href="systemd.link.xml" xpointer="architecture" />
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146 </variablelist>
147
148 </refsect1>
149
150 <refsect1>
151 <title>[Link] Section Options</title>
152
153 <para> The <literal>[Link]</literal> section accepts the following keys:</para>
154
155 <variablelist class='network-directives'>
156 <varlistentry>
157 <term><varname>MACAddress=</varname></term>
158 <listitem>
de25aae1 159 <para>The hardware address to set for the device.</para>
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160 </listitem>
161 </varlistentry>
162 <varlistentry>
163 <term><varname>MTUBytes=</varname></term>
164 <listitem>
165 <para>The maximum transmission unit in bytes to set for the
166 device. The usual suffixes K, M, G, are supported and are
167 understood to the base of 1024.</para>
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168 <para>Note that if IPv6 is enabled on the interface, and the MTU is chosen
169 below 1280 (the minimum MTU for IPv6) it will automatically be increased to this value.</para>
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170 </listitem>
171 </varlistentry>
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172 <varlistentry>
173 <term><varname>ARP=</varname></term>
174 <listitem>
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175 <para>Takes a boolean. If set to true, the ARP (low-level Address Resolution Protocol)
176 for this interface is enabled. When unset, the kernel's default will be used.</para>
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177 <para> For example, disabling ARP is useful when creating multiple MACVLAN or VLAN virtual
178 interfaces atop a single lower-level physical interface, which will then only serve as a
179 link/"bridge" device aggregating traffic to the same physical link and not participate in
180 the network otherwise.</para>
181 </listitem>
182 </varlistentry>
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183 <varlistentry>
184 <term><varname>Multicast=</varname></term>
185 <listitem>
9b6ffef3 186 <para>Takes a boolean. If set to true, the multicast flag on the device is enabled.</para>
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187 </listitem>
188 </varlistentry>
189 <varlistentry>
190 <term><varname>AllMulticast=</varname></term>
191 <listitem>
9b6ffef3 192 <para>Takes a boolean. If set to true, the driver retrieves all multicast packets from the network.
866e6b7a 193 This happens when multicast routing is enabled.</para>
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194 </listitem>
195 </varlistentry>
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196 <varlistentry>
197 <term><varname>Unmanaged=</varname></term>
198 <listitem>
9b6ffef3 199 <para>Takes a boolean. When <literal>yes</literal>, no attempts are
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200 made to bring up or configure matching links, equivalent to
201 when there are no matching network files. Defaults to
202 <literal>no</literal>.</para>
203 <para>This is useful for preventing later matching network
204 files from interfering with certain interfaces that are fully
205 controlled by other applications.</para>
206 </listitem>
207 </varlistentry>
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208 <varlistentry>
209 <term><varname>RequiredForOnline=</varname></term>
210 <listitem>
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211 <para>Takes a boolean or a minimum operational state and an optional maximum operational state.
212 Please see <citerefentry><refentrytitle>networkctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
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213 for possible operational states. When <literal>yes</literal>, the network is deemed required when
214 determining whether the system is online when running
215 <command>systemd-networkd-wait-online</command>. When <literal>no</literal>, the network is ignored
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216 when checking for online state. When a minimum operational state and an optional maximum operational
217 state are set, <literal>yes</literal> is implied, and this controls the minimum and maximum
218 operational state required for the network interface to be considered online.
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219 Defaults to <literal>yes</literal>.</para>
220
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221 <para>The network will be brought up normally in all cases, but in
222 the event that there is no address being assigned by DHCP or the
223 cable is not plugged in, the link will simply remain offline and be
8d6082e4 224 skipped automatically by <command>systemd-networkd-wait-online</command>
ca92fe36 225 if <literal>RequiredForOnline=no</literal>.</para>
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226 </listitem>
227 </varlistentry>
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228 </variablelist>
229 </refsect1>
230
231 <refsect1>
232 <title>[Network] Section Options</title>
233
234 <para>The <literal>[Network]</literal> section accepts the following keys:</para>
235
236 <variablelist class='network-directives'>
237 <varlistentry>
238 <term><varname>Description=</varname></term>
239 <listitem>
240 <para>A description of the device. This is only used for
241 presentation purposes.</para>
242 </listitem>
243 </varlistentry>
244 <varlistentry>
245 <term><varname>DHCP=</varname></term>
246 <listitem>
ad943783 247 <para>Enables DHCPv4 and/or DHCPv6 client support. Accepts
798d3a52 248 <literal>yes</literal>, <literal>no</literal>,
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249 <literal>ipv4</literal>, or <literal>ipv6</literal>. Defaults
250 to <literal>no</literal>.</para>
e88d8021 251
f5a8c43f 252 <para>Note that DHCPv6 will by default be triggered by Router
7f3fdb7f 253 Advertisement, if that is enabled, regardless of this parameter.
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254 By enabling DHCPv6 support explicitly, the DHCPv6 client will
255 be started regardless of the presence of routers on the link,
256 or what flags the routers pass. See
f921f573 257 <literal>IPv6AcceptRA=</literal>.</para>
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258
259 <para>Furthermore, note that by default the domain name
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260 specified through DHCP is not used for name resolution.
261 See option <option>UseDomains=</option> below.</para>
2ef322fc 262
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263 <para>See the <literal>[DHCPv4]</literal> or <literal>[DHCPv6]</literal> section below for
264 further configuration options for the DHCP client support.</para>
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265 </listitem>
266 </varlistentry>
267 <varlistentry>
268 <term><varname>DHCPServer=</varname></term>
269 <listitem>
68b7f7ac 270 <para>Takes a boolean. If set to <literal>yes</literal>, DHCPv4 server will be started. Defaults
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271 to <literal>no</literal>. Further settings for the DHCP
272 server may be set in the <literal>[DHCPServer]</literal>
273 section described below.</para>
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274 </listitem>
275 </varlistentry>
276 <varlistentry>
56fd6bf7 277 <term><varname>LinkLocalAddressing=</varname></term>
798d3a52 278 <listitem>
85fc09c9 279 <para>Enables link-local address autoconfiguration. Accepts <literal>yes</literal>,
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280 <literal>no</literal>, <literal>ipv4</literal>, <literal>ipv6</literal>,
281 <literal>fallback</literal>, or <literal>ipv4-fallback</literal>. If
282 <literal>fallback</literal> or <literal>ipv4-fallback</literal> is specified, then an IPv4
283 link-local address is configured only when DHCPv4 fails. If <literal>fallback</literal>,
284 an IPv6 link-local address is always configured, and if <literal>ipv4-fallback</literal>,
285 the address is not configured. Note that, the fallback mechanism works only when DHCPv4
286 client is enabled, that is, it requires <literal>DHCP=yes</literal> or
287 <literal>DHCP=ipv4</literal>. If <varname>Bridge=</varname> is set, defaults to
288 <literal>no</literal>, and if not, defaults to <literal>ipv6</literal>.
289 </para>
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290 </listitem>
291 </varlistentry>
292 <varlistentry>
293 <term><varname>IPv4LLRoute=</varname></term>
294 <listitem>
9b6ffef3 295 <para>Takes a boolean. If set to true, sets up the route needed for
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296 non-IPv4LL hosts to communicate with IPv4LL-only hosts. Defaults
297 to false.
298 </para>
299 </listitem>
300 </varlistentry>
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301 <varlistentry>
302 <term><varname>DefaultRouteOnDevice=</varname></term>
303 <listitem>
304 <para>Takes a boolean. If set to true, sets up the default route bound to the interface.
305 Defaults to false. This is useful when creating routes on point-to-point interfaces.
306 This is equivalent to e.g. the following.
307 <programlisting>ip route add default dev veth99</programlisting></para>
308 </listitem>
309 </varlistentry>
798d3a52 310 <varlistentry>
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311 <term><varname>IPv6Token=</varname></term>
312 <listitem>
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313 <para>Specifies an optional address generation mode and a required IPv6 address. If
314 the mode is present, the two parts must be separated with a colon
315 <literal><replaceable>mode</replaceable>:<replaceable>address</replaceable></literal>. The
316 address generation mode may be either <constant>prefixstable</constant> or
317 <constant>static</constant>. If not specified, <constant>static</constant> is assumed.
318 </para>
319 <para>When the mode is set to <constant>static</constant>, or unspecified, the lower bits of
320 the supplied address are combined with the upper bits of a prefix received in a Router Advertisement
321 message to form a complete address. Note that if multiple prefixes are received in an RA message, or in
322 multiple RA messages, addresses will be formed from each of them using the supplied address. This
323 mode implements SLAAC but uses a static interface identifier instead of an identifier generated
324 using the EUI-64 algorithm. Because the interface identifier is static, if Duplicate Address Detection
325 detects that the computed address is a duplicate (in use by another node on the link), then this
326 mode will fail to provide an address for that prefix.
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327 </para>
328 <para>When the mode is set to <literal>prefixstable</literal> the RFC 7217 algorithm for generating
329 interface identifiers will be used, but only when a prefix received in an RA message matches the supplied address.
330 See <ulink url="https://tools.ietf.org/html/rfc7217">RFC 7217</ulink>. Prefix matching will be attempted
331 against each <constant>prefixstable</constant> IPv6Token variable provided in the configuration; if a received
332 prefix does not match any of the provided addresses, then the EUI-64 algorithm will be used to form
333 an interface identifier for that prefix. This mode is also SLAAC, but with a potentially stable interface
334 identifier which does not directly map to the interface's hardware address.
335
336 Note that the <constant>prefixstable</constant> algorithm includes both the interface's name and
337 MAC address in the hash used to compute the interface identifier, so if either of those are changed the resulting
338 interface identifier (and address) will change, even if the prefix received in the RA message has not changed.
339
340 Note that if multiple <constant>prefixstable</constant> IPv6Token variables are supplied with addresses that
341 match a prefix received in an RA message, only the first one will be used to generate addresses.
5f506a55 342 </para>
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343 </listitem>
344 </varlistentry>
345 <varlistentry>
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346 <term><varname>LLMNR=</varname></term>
347 <listitem>
9b6ffef3 348 <para>Takes a boolean or <literal>resolve</literal>. When true,
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349 enables <ulink
350 url="https://tools.ietf.org/html/rfc4795">Link-Local
351 Multicast Name Resolution</ulink> on the link. When set to
352 <literal>resolve</literal>, only resolution is enabled,
353 but not host registration and announcement. Defaults to
354 true. This setting is read by
355 <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
356 </listitem>
357 </varlistentry>
358 <varlistentry>
359 <term><varname>MulticastDNS=</varname></term>
360 <listitem>
9b6ffef3 361 <para>Takes a boolean or <literal>resolve</literal>. When true,
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362 enables <ulink
363 url="https://tools.ietf.org/html/rfc6762">Multicast
364 DNS</ulink> support on the link. When set to
365 <literal>resolve</literal>, only resolution is enabled,
366 but not host or service registration and
367 announcement. Defaults to false. This setting is read by
368 <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
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369 </listitem>
370 </varlistentry>
30e59c84 371 <varlistentry>
c9299be2 372 <term><varname>DNSOverTLS=</varname></term>
30e59c84 373 <listitem>
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374 <para>Takes a boolean or <literal>opportunistic</literal>.
375 When true, enables
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376 <ulink
377 url="https://tools.ietf.org/html/rfc7858">DNS-over-TLS</ulink>
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378 support on the link.
379 When set to <literal>opportunistic</literal>, compatibility with
380 non-DNS-over-TLS servers is increased, by automatically
381 turning off DNS-over-TLS servers in this case.
382 This option defines a per-interface setting for
30e59c84 383 <citerefentry><refentrytitle>resolved.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>'s
c9299be2 384 global <varname>DNSOverTLS=</varname> option. Defaults to
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385 false. This setting is read by
386 <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
387 </listitem>
388 </varlistentry>
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389 <varlistentry>
390 <term><varname>DNSSEC=</varname></term>
391 <listitem>
9b6ffef3 392 <para>Takes a boolean. or
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393 <literal>allow-downgrade</literal>. When true, enables
394 <ulink
395 url="https://tools.ietf.org/html/rfc4033">DNSSEC</ulink>
396 DNS validation support on the link. When set to
397 <literal>allow-downgrade</literal>, compatibility with
398 non-DNSSEC capable networks is increased, by automatically
785889e5 399 turning off DNSSEC in this case. This option defines a
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400 per-interface setting for
401 <citerefentry><refentrytitle>resolved.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>'s
402 global <varname>DNSSEC=</varname> option. Defaults to
403 false. This setting is read by
404 <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
405 </listitem>
406 </varlistentry>
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407 <varlistentry>
408 <term><varname>DNSSECNegativeTrustAnchors=</varname></term>
409 <listitem><para>A space-separated list of DNSSEC negative
410 trust anchor domains. If specified and DNSSEC is enabled,
411 look-ups done via the interface's DNS server will be subject
412 to the list of negative trust anchors, and not require
413 authentication for the specified domains, or anything below
414 it. Use this to disable DNSSEC authentication for specific
415 private domains, that cannot be proven valid using the
416 Internet DNS hierarchy. Defaults to the empty list. This
417 setting is read by
418 <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
419 </listitem>
420 </varlistentry>
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421 <varlistentry>
422 <term><varname>LLDP=</varname></term>
423 <listitem>
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424 <para>Controls support for Ethernet LLDP packet reception. LLDP is a link-layer protocol commonly
425 implemented on professional routers and bridges which announces which physical port a system is connected
426 to, as well as other related data. Accepts a boolean or the special value
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427 <literal>routers-only</literal>. When true, incoming LLDP packets are accepted and a database of all LLDP
428 neighbors maintained. If <literal>routers-only</literal> is set only LLDP data of various types of routers
429 is collected and LLDP data about other types of devices ignored (such as stations, telephones and
7cececb2 430 others). If false, LLDP reception is disabled. Defaults to <literal>routers-only</literal>. Use
34437b4f 431 <citerefentry><refentrytitle>networkctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> to query the
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432 collected neighbor data. LLDP is only available on Ethernet links. See <varname>EmitLLDP=</varname> below
433 for enabling LLDP packet emission from the local system.
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434 </para>
435 </listitem>
436 </varlistentry>
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437 <varlistentry>
438 <term><varname>EmitLLDP=</varname></term>
439 <listitem>
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440 <para>Controls support for Ethernet LLDP packet emission. Accepts a boolean parameter or the special values
441 <literal>nearest-bridge</literal>, <literal>non-tpmr-bridge</literal> and
442 <literal>customer-bridge</literal>. Defaults to false, which turns off LLDP packet emission. If not false,
443 a short LLDP packet with information about the local system is sent out in regular intervals on the
444 link. The LLDP packet will contain information about the local host name, the local machine ID (as stored
445 in <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>) and the
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446 local interface name, as well as the pretty hostname of the system (as set in
447 <citerefentry><refentrytitle>machine-info</refentrytitle><manvolnum>5</manvolnum></citerefentry>). LLDP
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448 emission is only available on Ethernet links. Note that this setting passes data suitable for
449 identification of host to the network and should thus not be enabled on untrusted networks, where such
450 identification data should not be made available. Use this option to permit other systems to identify on
451 which interfaces they are connected to this system. The three special values control propagation of the
452 LLDP packets. The <literal>nearest-bridge</literal> setting permits propagation only to the nearest
453 connected bridge, <literal>non-tpmr-bridge</literal> permits propagation across Two-Port MAC Relays, but
454 not any other bridges, and <literal>customer-bridge</literal> permits propagation until a customer bridge
455 is reached. For details about these concepts, see <ulink
6a1bae83 456 url="https://standards.ieee.org/findstds/standard/802.1AB-2016.html">IEEE 802.1AB-2016</ulink>. Note that
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457 configuring this setting to true is equivalent to <literal>nearest-bridge</literal>, the recommended and
458 most restricted level of propagation. See <varname>LLDP=</varname> above for an option to enable LLDP
459 reception.</para>
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460 </listitem>
461 </varlistentry>
e9a8c550 462
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463 <varlistentry>
464 <term><varname>BindCarrier=</varname></term>
465 <listitem>
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466 <para>A link name or a list of link names. When set, controls the behavior of the current
467 link. When all links in the list are in an operational down state, the current link is brought
468 down. When at least one link has carrier, the current interface is brought up.
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469 </para>
470 </listitem>
471 </varlistentry>
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472 <varlistentry>
473 <term><varname>Address=</varname></term>
474 <listitem>
475 <para>A static IPv4 or IPv6 address and its prefix length,
476 separated by a <literal>/</literal> character. Specify
477 this key more than once to configure several addresses.
478 The format of the address must be as described in
3ba3a79d 479 <citerefentry project='man-pages'><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
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480 This is a short-hand for an [Address] section only
481 containing an Address key (see below). This option may be
482 specified more than once.
483 </para>
484
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485 <para>If the specified address is <literal>0.0.0.0</literal> (for IPv4) or <literal>::</literal>
486 (for IPv6), a new address range of the requested size is automatically allocated from a
487 system-wide pool of unused ranges. Note that the prefix length must be equal or larger than 8 for
488 IPv4, and 64 for IPv6. The allocated range is checked against all current network interfaces and
489 all known network configuration files to avoid address range conflicts. The default system-wide
490 pool consists of 192.168.0.0/16, 172.16.0.0/12 and 10.0.0.0/8 for IPv4, and fd00::/8 for IPv6.
491 This functionality is useful to manage a large number of dynamically created network interfaces
492 with the same network configuration and automatic address range assignment.</para>
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493
494 </listitem>
495 </varlistentry>
496 <varlistentry>
497 <term><varname>Gateway=</varname></term>
498 <listitem>
499 <para>The gateway address, which must be in the format
500 described in
3ba3a79d 501 <citerefentry project='man-pages'><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
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502 This is a short-hand for a [Route] section only containing
503 a Gateway key. This option may be specified more than
504 once.</para>
505 </listitem>
506 </varlistentry>
507 <varlistentry>
508 <term><varname>DNS=</varname></term>
509 <listitem>
510 <para>A DNS server address, which must be in the format
511 described in
3ba3a79d 512 <citerefentry project='man-pages'><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
f41b446a 513 This option may be specified more than once. This setting is read by
3df9bec5 514 <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
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515 </listitem>
516 </varlistentry>
517 <varlistentry>
518 <term><varname>Domains=</varname></term>
519 <listitem>
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520 <para>A whitespace-separated list of domains which should be resolved using the DNS servers on
521 this link. Each item in the list should be a domain name, optionally prefixed with a tilde
522 (<literal>~</literal>). The domains with the prefix are called "routing-only domains". The
523 domains without the prefix are called "search domains" and are first used as search suffixes for
524 extending single-label host names (host names containing no dots) to become fully qualified
525 domain names (FQDNs). If a single-label host name is resolved on this interface, each of the
526 specified search domains are appended to it in turn, converting it into a fully qualified domain
527 name, until one of them may be successfully resolved.</para>
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528
529 <para>Both "search" and "routing-only" domains are used for routing of DNS queries: look-ups for host names
530 ending in those domains (hence also single label names, if any "search domains" are listed), are routed to
531 the DNS servers configured for this interface. The domain routing logic is particularly useful on
532 multi-homed hosts with DNS servers serving particular private DNS zones on each interface.</para>
533
534 <para>The "routing-only" domain <literal>~.</literal> (the tilde indicating definition of a routing domain,
535 the dot referring to the DNS root domain which is the implied suffix of all valid DNS names) has special
536 effect. It causes all DNS traffic which does not match another configured domain routing entry to be routed
537 to DNS servers specified for this interface. This setting is useful to prefer a certain set of DNS servers
538 if a link on which they are connected is available.</para>
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539
540 <para>This setting is read by
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541 <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
542 "Search domains" correspond to the <varname>domain</varname> and <varname>search</varname> entries in
98e9d710 543 <citerefentry project='man-pages'><refentrytitle>resolv.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
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544 Domain name routing has no equivalent in the traditional glibc API, which has no concept of domain
545 name servers limited to a specific link.</para>
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546 </listitem>
547 </varlistentry>
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548 <varlistentry>
549 <term><varname>DNSDefaultRoute=</varname></term>
550 <listitem>
551 <para>Takes a boolean argument. If true, this link's configured DNS servers are used for resolving domain
552 names that do not match any link's configured <varname>Domains=</varname> setting. If false, this link's
553 configured DNS servers are never used for such domains, and are exclusively used for resolving names that
554 match at least one of the domains configured on this link. If not specified defaults to an automatic mode:
555 queries not matching any link's configured domains will be routed to this link if it has no routing-only
556 domains configured.</para>
557 </listitem>
558 </varlistentry>
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559 <varlistentry>
560 <term><varname>NTP=</varname></term>
561 <listitem>
f41b446a 562 <para>An NTP server address. This option may be specified more than once. This setting is read by
3df9bec5 563 <citerefentry><refentrytitle>systemd-timesyncd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
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564 </listitem>
565 </varlistentry>
566 <varlistentry>
567 <term><varname>IPForward=</varname></term>
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568 <listitem><para>Configures IP packet forwarding for the
569 system. If enabled, incoming packets on any network
570 interface will be forwarded to any other interfaces
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571 according to the routing table. Takes a boolean,
572 or the values <literal>ipv4</literal> or
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573 <literal>ipv6</literal>, which only enable IP packet
574 forwarding for the specified address family. This controls
575 the <filename>net.ipv4.ip_forward</filename> and
576 <filename>net.ipv6.conf.all.forwarding</filename> sysctl
577 options of the network interface (see <ulink
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578 url="https://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt">ip-sysctl.txt</ulink>
579 for details about sysctl options). Defaults to
580 <literal>no</literal>.</para>
581
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582 <para>Note: this setting controls a global kernel option,
583 and does so one way only: if a network that has this setting
584 enabled is set up the global setting is turned on. However,
585 it is never turned off again, even after all networks with
586 this setting enabled are shut down again.</para>
587
588 <para>To allow IP packet forwarding only between specific
589 network interfaces use a firewall.</para>
4046d836 590 </listitem>
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591 </varlistentry>
592 <varlistentry>
593 <term><varname>IPMasquerade=</varname></term>
594 <listitem><para>Configures IP masquerading for the network
b938cb90 595 interface. If enabled, packets forwarded from the network
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596 interface will be appear as coming from the local host.
597 Takes a boolean argument. Implies
5c82dd13 598 <varname>IPForward=ipv4</varname>. Defaults to
4046d836 599 <literal>no</literal>.</para></listitem>
798d3a52 600 </varlistentry>
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601 <varlistentry>
602 <term><varname>IPv6PrivacyExtensions=</varname></term>
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603 <listitem><para>Configures use of stateless temporary
604 addresses that change over time (see <ulink
605 url="https://tools.ietf.org/html/rfc4941">RFC 4941</ulink>,
606 Privacy Extensions for Stateless Address Autoconfiguration
607 in IPv6). Takes a boolean or the special values
608 <literal>prefer-public</literal> and
b938cb90 609 <literal>kernel</literal>. When true, enables the privacy
1f0d9695 610 extensions and prefers temporary addresses over public
b938cb90 611 addresses. When <literal>prefer-public</literal>, enables the
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612 privacy extensions, but prefers public addresses over
613 temporary addresses. When false, the privacy extensions
b938cb90 614 remain disabled. When <literal>kernel</literal>, the kernel's
1f0d9695 615 default setting will be left in place. Defaults to
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616 <literal>no</literal>.</para></listitem>
617 </varlistentry>
941d0aa8 618 <varlistentry>
f921f573 619 <term><varname>IPv6AcceptRA=</varname></term>
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620 <listitem><para>Takes a boolean. Controls IPv6 Router Advertisement (RA) reception support for the
621 interface. If true, RAs are accepted; if false, RAs are ignored. When RAs are accepted, they may
622 trigger the start of the DHCPv6 client if the relevant flags are set in the RA data, or if no
623 routers are found on the link. The default is to disable RA reception for bridge devices or when IP
624 forwarding is enabled, and to enable it otherwise. Cannot be enabled on bond devices and when link
86b52a39 625 local addressing is disabled.</para>
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626
627 <para>Further settings for the IPv6 RA support may be configured in the
f921f573 628 <literal>[IPv6AcceptRA]</literal> section, see below.</para>
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629
630 <para>Also see <ulink
631 url="https://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt">ip-sysctl.txt</ulink> in the kernel
632 documentation regarding <literal>accept_ra</literal>, but note that systemd's setting of
633 <constant>1</constant> (i.e. true) corresponds to kernel's setting of <constant>2</constant>.</para>
c4a05aa1 634
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635 <para>Note that kernel's implementation of the IPv6 RA protocol is always disabled,
636 regardless of this setting. If this option is enabled, a userspace implementation of the IPv6
637 RA protocol is used, and the kernel's own implementation remains disabled, since
638 <command>systemd-networkd</command> needs to know all details supplied in the advertisements,
639 and these are not available from the kernel if the kernel's own implementation is used.</para>
ebf98081 640 </listitem>
941d0aa8 641 </varlistentry>
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642 <varlistentry>
643 <term><varname>IPv6DuplicateAddressDetection=</varname></term>
a8eaaee7 644 <listitem><para>Configures the amount of IPv6 Duplicate
025314d9 645 Address Detection (DAD) probes to send. When unset, the kernel's default will be used.
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646 </para></listitem>
647 </varlistentry>
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648 <varlistentry>
649 <term><varname>IPv6HopLimit=</varname></term>
650 <listitem><para>Configures IPv6 Hop Limit. For each router that
651 forwards the packet, the hop limit is decremented by 1. When the
652 hop limit field reaches zero, the packet is discarded.
025314d9 653 When unset, the kernel's default will be used.
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654 </para></listitem>
655 </varlistentry>
23d8b221 656 <varlistentry>
8f9a206b 657 <term><varname>IPv4ProxyARP=</varname></term>
9b6ffef3 658 <listitem><para>Takes a boolean. Configures proxy ARP for IPv4. Proxy ARP is the technique in which one host,
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659 usually a router, answers ARP requests intended for another machine. By "faking" its identity,
660 the router accepts responsibility for routing packets to the "real" destination. (see <ulink
661 url="https://tools.ietf.org/html/rfc1027">RFC 1027</ulink>.
025314d9 662 When unset, the kernel's default will be used.
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663 </para></listitem>
664 </varlistentry>
a0e5c15d 665 <varlistentry>
465dfe59 666 <term><varname>IPv6ProxyNDP=</varname></term>
9b6ffef3 667 <listitem><para>Takes a boolean. Configures proxy NDP for IPv6. Proxy NDP (Neighbor Discovery
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668 Protocol) is a technique for IPv6 to allow routing of addresses to a different
669 destination when peers expect them to be present on a certain physical link.
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670 In this case a router answers Neighbour Advertisement messages intended for
671 another machine by offering its own MAC address as destination.
465dfe59 672 Unlike proxy ARP for IPv4, it is not enabled globally, but will only send Neighbour
a0e5c15d 673 Advertisement messages for addresses in the IPv6 neighbor proxy table,
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674 which can also be shown by <command>ip -6 neighbour show proxy</command>.
675 systemd-networkd will control the per-interface `proxy_ndp` switch for each configured
676 interface depending on this option.
025314d9 677 When unset, the kernel's default will be used.
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678 </para></listitem>
679 </varlistentry>
680 <varlistentry>
681 <term><varname>IPv6ProxyNDPAddress=</varname></term>
682 <listitem><para>An IPv6 address, for which Neighbour Advertisement messages will be
683 proxied. This option may be specified more than once. systemd-networkd will add the
684 <option>IPv6ProxyNDPAddress=</option> entries to the kernel's IPv6 neighbor proxy table.
964c4eda 685 This option implies <option>IPv6ProxyNDP=yes</option> but has no effect if
025314d9 686 <option>IPv6ProxyNDP</option> has been set to false. When unset, the kernel's default will be used.
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687 </para></listitem>
688 </varlistentry>
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689 <varlistentry>
690 <term><varname>IPv6PrefixDelegation=</varname></term>
691 <listitem><para>Whether to enable or disable Router Advertisement sending on a link.
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692 Allowed values are <literal>static</literal> which distributes prefixes as defined in
693 the <literal>[IPv6PrefixDelegation]</literal> and any <literal>[IPv6Prefix]</literal>
694 sections, <literal>dhcpv6</literal> which requests prefixes using a DHCPv6 client
695 configured for another link and any values configured in the
696 <literal>[IPv6PrefixDelegation]</literal> section while ignoring all static prefix
697 configuration sections, <literal>yes</literal> which uses both static configuration
698 and DHCPv6, and <literal>false</literal> which turns off IPv6 prefix delegation
699 altogether. Defaults to <literal>false</literal>. See the
700 <literal>[IPv6PrefixDelegation]</literal> and the <literal>[IPv6Prefix]</literal>
701 sections for more configuration options.
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702 </para></listitem>
703 </varlistentry>
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704 <varlistentry>
705 <term><varname>IPv6MTUBytes=</varname></term>
706 <listitem><para>Configures IPv6 maximum transmission unit (MTU).
025314d9 707 An integer greater than or equal to 1280 bytes. When unset, the kernel's default will be used.
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708 </para></listitem>
709 </varlistentry>
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710 <varlistentry>
711 <term><varname>Bridge=</varname></term>
712 <listitem>
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713 <para>The name of the bridge to add the link to. See
714 <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
715 </para>
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716 </listitem>
717 </varlistentry>
718 <varlistentry>
719 <term><varname>Bond=</varname></term>
720 <listitem>
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721 <para>The name of the bond to add the link to. See
722 <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
723 </para>
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724 </listitem>
725 </varlistentry>
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726 <varlistentry>
727 <term><varname>VRF=</varname></term>
728 <listitem>
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729 <para>The name of the VRF to add the link to. See
730 <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
731 </para>
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732 </listitem>
733 </varlistentry>
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734 <varlistentry>
735 <term><varname>VLAN=</varname></term>
736 <listitem>
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737 <para>The name of a VLAN to create on the link. See
738 <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
739 This option may be specified more than once.</para>
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740 </listitem>
741 </varlistentry>
2479c4fe 742 <varlistentry>
743 <term><varname>IPVLAN=</varname></term>
744 <listitem>
745 <para>The name of a IPVLAN to create on the link. See
746 <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
747 This option may be specified more than once.</para>
748 </listitem>
749 </varlistentry>
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750 <varlistentry>
751 <term><varname>MACVLAN=</varname></term>
752 <listitem>
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753 <para>The name of a MACVLAN to create on the link. See
754 <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
755 This option may be specified more than once.</para>
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756 </listitem>
757 </varlistentry>
758 <varlistentry>
759 <term><varname>VXLAN=</varname></term>
760 <listitem>
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761 <para>The name of a VXLAN to create on the link. See
762 <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
763 This option may be specified more than once.</para>
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764 </listitem>
765 </varlistentry>
766 <varlistentry>
767 <term><varname>Tunnel=</varname></term>
768 <listitem>
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769 <para>The name of a Tunnel to create on the link. See
770 <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
771 This option may be specified more than once.</para>
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772 </listitem>
773 </varlistentry>
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774 <varlistentry>
775 <term><varname>MACsec=</varname></term>
776 <listitem>
777 <para>The name of a MACsec device to create on the link. See
778 <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
779 This option may be specified more than once.</para>
780 </listitem>
781 </varlistentry>
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782 <varlistentry>
783 <term><varname>ActiveSlave=</varname></term>
784 <listitem>
9b6ffef3 785 <para>Takes a boolean. Specifies the new active slave. The <literal>ActiveSlave=</literal>
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786 option is only valid for following modes:
787 <literal>active-backup</literal>,
788 <literal>balance-alb</literal> and
789 <literal>balance-tlb</literal>. Defaults to false.
790 </para>
791 </listitem>
792 </varlistentry>
793 <varlistentry>
794 <term><varname>PrimarySlave=</varname></term>
795 <listitem>
9b6ffef3 796 <para>Takes a boolean. Specifies which slave is the primary device. The specified
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797 device will always be the active slave while it is available. Only when the
798 primary is off-line will alternate devices be used. This is useful when
799 one slave is preferred over another, e.g. when one slave has higher throughput
800 than another. The <literal>PrimarySlave=</literal> option is only valid for
801 following modes:
802 <literal>active-backup</literal>,
803 <literal>balance-alb</literal> and
804 <literal>balance-tlb</literal>. Defaults to false.
805 </para>
806 </listitem>
807 </varlistentry>
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808 <varlistentry>
809 <term><varname>ConfigureWithoutCarrier=</varname></term>
810 <listitem>
9b6ffef3 811 <para>Takes a boolean. Allows networkd to configure a specific link even if it has no carrier.
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812 Defaults to false.
813 </para>
814 </listitem>
815 </varlistentry>
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816 <varlistentry>
817 <term><varname>IgnoreCarrierLoss=</varname></term>
818 <listitem>
819 <para>A boolean. Allows networkd to retain both the static and dynamic configuration of the
820 interface even if its carrier is lost. Defaults to false.
821 </para>
822 </listitem>
823 </varlistentry>
98d20a17 824 <varlistentry>
825 <term><varname>Xfrm=</varname></term>
826 <listitem>
827 <para>The name of the xfrm to create on the link. See
828 <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
829 This option may be specified more than once.</para>
830 </listitem>
831 </varlistentry>
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832 <varlistentry>
833 <term><varname>KeepConfiguration=</varname></term>
834 <listitem>
835 <para>Takes a boolean or one of <literal>static</literal>, <literal>dhcp-on-stop</literal>,
836 <literal>dhcp</literal>. When <literal>static</literal>, <command>systemd-networkd</command>
837 will not drop static addresses and routes on starting up process. When set to
838 <literal>dhcp-on-stop</literal>, <command>systemd-networkd</command> will not drop addresses
839 and routes on stopping the daemon. When <literal>dhcp</literal>,
840 the addresses and routes provided by a DHCP server will never be dropped even if the DHCP
841 lease expires. This is contrary to the DHCP specification, but may be the best choice if,
842 e.g., the root filesystem relies on this connection. The setting <literal>dhcp</literal>
843 implies <literal>dhcp-on-stop</literal>, and <literal>yes</literal> implies
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844 <literal>dhcp</literal> and <literal>static</literal>. Defaults to <literal>no</literal>.
845 </para>
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846 </listitem>
847 </varlistentry>
93b4dab5 848
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849 </variablelist>
850
851 </refsect1>
852
853 <refsect1>
854 <title>[Address] Section Options</title>
855
856 <para>An <literal>[Address]</literal> section accepts the
857 following keys. Specify several <literal>[Address]</literal>
858 sections to configure several addresses.</para>
859
860 <variablelist class='network-directives'>
861 <varlistentry>
862 <term><varname>Address=</varname></term>
863 <listitem>
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864 <para>As in the <literal>[Network]</literal> section. This key is mandatory. Each
865 <literal>[Address]</literal> section can contain one <varname>Address=</varname> setting.</para>
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866 </listitem>
867 </varlistentry>
868 <varlistentry>
869 <term><varname>Peer=</varname></term>
870 <listitem>
871 <para>The peer address in a point-to-point connection.
4e68898e 872 Accepts the same format as the <varname>Address=</varname>
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873 key.</para>
874 </listitem>
875 </varlistentry>
876 <varlistentry>
877 <term><varname>Broadcast=</varname></term>
878 <listitem>
879 <para>The broadcast address, which must be in the format
880 described in
3ba3a79d 881 <citerefentry project='man-pages'><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
798d3a52 882 This key only applies to IPv4 addresses. If it is not
4e68898e 883 given, it is derived from the <varname>Address=</varname>
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884 key.</para>
885 </listitem>
886 </varlistentry>
887 <varlistentry>
888 <term><varname>Label=</varname></term>
889 <listitem>
890 <para>An address label.</para>
891 </listitem>
892 </varlistentry>
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893 <varlistentry>
894 <term><varname>PreferredLifetime=</varname></term>
895 <listitem>
896 <para>Allows the default "preferred lifetime" of the address to be overridden.
897 Only three settings are accepted: <literal>forever</literal> or <literal>infinity</literal>
898 which is the default and means that the address never expires, and <literal>0</literal> which means
899 that the address is considered immediately "expired" and will not be used,
900 unless explicitly requested. A setting of PreferredLifetime=0 is useful for
901 addresses which are added to be used only by a specific application,
902 which is then configured to use them explicitly.</para>
903 </listitem>
904 </varlistentry>
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905 <varlistentry>
906 <term><varname>Scope=</varname></term>
907 <listitem>
908 <para>The scope of the address, which can be <literal>global</literal>,
909 <literal>link</literal> or <literal>host</literal> or an unsigned integer ranges 0 to 255.
910 Defaults to <literal>global</literal>.</para>
911 </listitem>
912 </varlistentry>
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913 <varlistentry>
914 <term><varname>HomeAddress=</varname></term>
915 <listitem>
9b6ffef3 916 <para>Takes a boolean. Designates this address the "home address" as defined in
e63be084
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917 <ulink url="https://tools.ietf.org/html/rfc6275">RFC 6275</ulink>.
918 Supported only on IPv6. Defaults to false.</para>
919 </listitem>
920 </varlistentry>
921 <varlistentry>
922 <term><varname>DuplicateAddressDetection=</varname></term>
923 <listitem>
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SS
924 <para>Takes one of <literal>ipv4</literal>, <literal>ipv6</literal>,
925 <literal>both</literal>, <literal>none</literal>. When <literal>ipv4</literal>,
926 performs IPv4 Duplicate Address Detection. See
927 <ulink url="https://tools.ietf.org/html/rfc5227">RFC 5224</ulink>.
928 When <literal>ipv6</literal>, performs IPv6 Duplicate Address Detection. See
929 <ulink url="https://tools.ietf.org/html/rfc4862">RFC 4862</ulink>.
930 Defaults to <literal>ipv6</literal>.</para>
e63be084
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931 </listitem>
932 </varlistentry>
933 <varlistentry>
934 <term><varname>ManageTemporaryAddress=</varname></term>
935 <listitem>
9b6ffef3 936 <para>Takes a boolean. If true the kernel manage temporary addresses created
e63be084
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937 from this one as template on behalf of Privacy Extensions
938 <ulink url="https://tools.ietf.org/html/rfc3041">RFC 3041</ulink>. For this to become
939 active, the use_tempaddr sysctl setting has to be set to a value greater than zero.
11fcfc53 940 The given address needs to have a prefix length of 64. This flag allows using privacy
e63be084
SS
941 extensions in a manually configured network, just like if stateless auto-configuration
942 was active. Defaults to false. </para>
943 </listitem>
944 </varlistentry>
945 <varlistentry>
de697db0 946 <term><varname>AddPrefixRoute=</varname></term>
e63be084 947 <listitem>
de697db0
YW
948 <para>Takes a boolean. When true, the prefix route for the address is automatically added.
949 Defaults to true.</para>
e63be084
SS
950 </listitem>
951 </varlistentry>
952 <varlistentry>
953 <term><varname>AutoJoin=</varname></term>
954 <listitem>
9b6ffef3 955 <para>Takes a boolean. Joining multicast group on ethernet level via
e63be084
SS
956 <command>ip maddr</command> command would not work if we have an Ethernet switch that does
957 IGMP snooping since the switch would not replicate multicast packets on ports that did not
958 have IGMP reports for the multicast addresses. Linux vxlan interfaces created via
959 <command>ip link add vxlan</command> or networkd's netdev kind vxlan have the group option
960 that enables then to do the required join. By extending ip address command with option
961 <literal>autojoin</literal> we can get similar functionality for openvswitch (OVS) vxlan
962 interfaces as well as other tunneling mechanisms that need to receive multicast traffic.
963 Defaults to <literal>no</literal>.</para>
964 </listitem>
965 </varlistentry>
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966 </variablelist>
967 </refsect1>
968
e4a71bf3
WKI
969 <refsect1>
970 <title>[Neighbor] Section Options</title>
971 <para>A <literal>[Neighbor]</literal> section accepts the
972 following keys. The neighbor section adds a permanent, static
973 entry to the neighbor table (IPv6) or ARP table (IPv4) for
974 the given hardware address on the links matched for the network.
975 Specify several <literal>[Neighbor]</literal> sections to configure
976 several static neighbors.</para>
977
978 <variablelist class='network-directives'>
979 <varlistentry>
980 <term><varname>Address=</varname></term>
981 <listitem>
982 <para>The IP address of the neighbor.</para>
983 </listitem>
984 </varlistentry>
985 <varlistentry>
b956364d 986 <term><varname>LinkLayerAddress=</varname></term>
e4a71bf3 987 <listitem>
b956364d 988 <para>The link layer address (MAC address or IP address) of the neighbor.</para>
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989 </listitem>
990 </varlistentry>
991 </variablelist>
992 </refsect1>
993
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SS
994 <refsect1>
995 <title>[IPv6AddressLabel] Section Options</title>
996
997 <para>An <literal>[IPv6AddressLabel]</literal> section accepts the
998 following keys. Specify several <literal>[IPv6AddressLabel]</literal>
785889e5 999 sections to configure several address labels. IPv6 address labels are
95b74ef6
SS
1000 used for address selection. See <ulink url="https://tools.ietf.org/html/rfc3484">RFC 3484</ulink>.
1001 Precedence is managed by userspace, and only the label itself is stored in the kernel</para>
1002
1003 <variablelist class='network-directives'>
1004 <varlistentry>
1005 <term><varname>Label=</varname></term>
1006 <listitem>
1007 <para> The label for the prefix (an unsigned integer) ranges 0 to 4294967294.
1008 0xffffffff is reserved. This key is mandatory.</para>
1009 </listitem>
1010 </varlistentry>
1011 <varlistentry>
1012 <term><varname>Prefix=</varname></term>
1013 <listitem>
1014 <para>IPv6 prefix is an address with a prefix length, separated by a slash <literal>/</literal> character.
1015 This key is mandatory. </para>
1016 </listitem>
1017 </varlistentry>
1018 </variablelist>
1019 </refsect1>
1020
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SS
1021 <refsect1>
1022 <title>[RoutingPolicyRule] Section Options</title>
1023
1024 <para>An <literal>[RoutingPolicyRule]</literal> section accepts the
1025 following keys. Specify several <literal>[RoutingPolicyRule]</literal>
1026 sections to configure several rules.</para>
1027
1028 <variablelist class='network-directives'>
1029 <varlistentry>
1030 <term><varname>TypeOfService=</varname></term>
1031 <listitem>
1032 <para>Specifies the type of service to match a number between 0 to 255.</para>
1033 </listitem>
1034 </varlistentry>
1035 <varlistentry>
1036 <term><varname>From=</varname></term>
1037 <listitem>
1038 <para>Specifies the source address prefix to match. Possibly followed by a slash and the prefix length.</para>
1039 </listitem>
1040 </varlistentry>
1041 <varlistentry>
1042 <term><varname>To=</varname></term>
1043 <listitem>
1044 <para>Specifies the destination address prefix to match. Possibly followed by a slash and the prefix length.</para>
1045 </listitem>
1046 </varlistentry>
1047 <varlistentry>
1048 <term><varname>FirewallMark=</varname></term>
1049 <listitem>
1050 <para>Specifies the iptables firewall mark value to match (a number between 1 and 4294967295).</para>
1051 </listitem>
1052 </varlistentry>
1053 <varlistentry>
1054 <term><varname>Table=</varname></term>
1055 <listitem>
41b90a1e
YW
1056 <para>Specifies the routing table identifier to lookup if the rule selector matches. Takes
1057 one of <literal>default</literal>, <literal>main</literal>, and <literal>local</literal>,
1058 or a number between 1 and 4294967295. Defaults to <literal>main</literal>.</para>
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SS
1059 </listitem>
1060 </varlistentry>
1061 <varlistentry>
1062 <term><varname>Priority=</varname></term>
1063 <listitem>
1064 <para>Specifies the priority of this rule. <varname>Priority=</varname> is an unsigned
1065 integer. Higher number means lower priority, and rules get processed in order of increasing number.</para>
1066 </listitem>
1067 </varlistentry>
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SS
1068 <varlistentry>
1069 <term><varname>IncomingInterface=</varname></term>
1070 <listitem>
1071 <para>Specifies incoming device to match. If the interface is loopback, the rule only matches packets originating from this host.</para>
1072 </listitem>
1073 </varlistentry>
1074 <varlistentry>
1075 <term><varname>OutgoingInterface=</varname></term>
1076 <listitem>
1077 <para>Specifies the outgoing device to match. The outgoing interface is only available for packets originating from local sockets that are bound to a device.</para>
1078 </listitem>
1079 </varlistentry>
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SS
1080 <varlistentry>
1081 <term><varname>SourcePort=</varname></term>
1082 <listitem>
1083 <para>Specifies the source IP port or IP port range match in forwarding information base (FIB) rules.
1084 A port range is specified by the lower and upper port separated by a dash. Defaults to unset.</para>
1085 </listitem>
1086 </varlistentry>
1087 <varlistentry>
1088 <term><varname>DestinationPort=</varname></term>
1089 <listitem>
1090 <para>Specifies the destination IP port or IP port range match in forwarding information base (FIB) rules.
1091 A port range is specified by the lower and upper port separated by a dash. Defaults to unset.</para>
1092 </listitem>
1093 </varlistentry>
1094 <varlistentry>
97f9df9e 1095 <term><varname>IPProtocol=</varname></term>
926062f0 1096 <listitem>
3a269dcf
YW
1097 <para>Specifies the IP protocol to match in forwarding information base (FIB) rules. Takes IP protocol name such as <literal>tcp</literal>,
1098 <literal>udp</literal> or <literal>sctp</literal>, or IP protocol number such as <literal>6</literal> for <literal>tcp</literal> or
1099 <literal>17</literal> for <literal>udp</literal>.
926062f0
SS
1100 Defaults to unset.</para>
1101 </listitem>
1102 </varlistentry>
8b220643
SS
1103 <varlistentry>
1104 <term><varname>InvertRule=</varname></term>
1105 <listitem>
53e1ba28 1106 <para>A boolean. Specifies whether the rule is to be inverted. Defaults to false.</para>
8b220643
SS
1107 </listitem>
1108 </varlistentry>
f6c6ff97
YW
1109 <varlistentry>
1110 <term><varname>Family=</varname></term>
1111 <listitem>
1112 <para>Takes a special value <literal>ipv4</literal>, <literal>ipv6</literal>, or
1113 <literal>both</literal>. By default, the address family is determined by the address
1114 specified in <varname>To=</varname> or <varname>From=</varname>. If neither
1115 <varname>To=</varname> nor <varname>From=</varname> are specified, then defaults to
1116 <literal>ipv4</literal>.</para>
1117 </listitem>
1118 </varlistentry>
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YW
1119 <varlistentry>
1120 <term><varname>User=</varname></term>
1121 <listitem>
1122 <para>Takes a username, a user ID, or a range of user IDs separated by a dash. Defaults to
1123 unset.</para>
1124 </listitem>
1125 </varlistentry>
53e1ba28
NF
1126 <varlistentry>
1127 <term><varname>SuppressPrefixLength=</varname></term>
1128 <listitem>
1129 <para>Takes a number <replaceable>N</replaceable> in the range 0-128 and rejects routing
1130 decisions that have a prefix length of <replaceable>N</replaceable> or less. Defaults to
1131 unset.</para>
1132 </listitem>
1133 </varlistentry>
bce67bbe 1134 </variablelist>
c16c7808
SS
1135 </refsect1>
1136
1137 <refsect1>
1138 <title>[NextHop] Section Options</title>
1139 <para>The <literal>[NextHop]</literal> section accepts the
1140 following keys. Specify several <literal>[NextHop]</literal>
1141 sections to configure several nexthop. Nexthop is used to manipulate entries in the kernel's nexthop
1142 tables.</para>
1143
1144 <variablelist class='network-directives'>
1145 <varlistentry>
1146 <term><varname>Gateway=</varname></term>
1147 <listitem>
1148 <para>As in the <literal>[Network]</literal> section. This is mandatory.</para>
1149 </listitem>
1150 </varlistentry>
1151 <varlistentry>
1152 <term><varname>Id=</varname></term>
1153 <listitem>
1154 <para>The id of the nexthop (an unsigned integer). If unspecified or '0' then automatically chosen by kernel.</para>
1155 </listitem>
1156 </varlistentry>
1157 </variablelist>
bce67bbe
SS
1158 </refsect1>
1159
798d3a52
ZJS
1160 <refsect1>
1161 <title>[Route] Section Options</title>
1162 <para>The <literal>[Route]</literal> section accepts the
1163 following keys. Specify several <literal>[Route]</literal>
1164 sections to configure several routes.</para>
1165
1166 <variablelist class='network-directives'>
1167 <varlistentry>
1168 <term><varname>Gateway=</varname></term>
1169 <listitem>
427928ca
ZJS
1170 <para>Takes the gateway address or special value <literal>_dhcp</literal>. If
1171 <literal>_dhcp</literal>, then the gateway address provided by DHCP (or in the IPv6 case,
1985c54f 1172 provided by IPv6 RA) is used.</para>
798d3a52
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1173 </listitem>
1174 </varlistentry>
28959f7d 1175 <varlistentry>
9cb8c559 1176 <term><varname>GatewayOnLink=</varname></term>
28959f7d 1177 <listitem>
9b6ffef3 1178 <para>Takes a boolean. If set to true, the kernel does not have
28959f7d
SS
1179 to check if the gateway is reachable directly by the current machine (i.e., the kernel does
1180 not need to check if the gateway is attached to the local network), so that we can insert the
9b6ffef3 1181 route in the kernel table without it being complained about. Defaults to <literal>no</literal>.
28959f7d
SS
1182 </para>
1183 </listitem>
1184 </varlistentry>
798d3a52
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1185 <varlistentry>
1186 <term><varname>Destination=</varname></term>
1187 <listitem>
1188 <para>The destination prefix of the route. Possibly
b938cb90 1189 followed by a slash and the prefix length. If omitted, a
798d3a52
ZJS
1190 full-length host route is assumed.</para>
1191 </listitem>
1192 </varlistentry>
1193 <varlistentry>
1194 <term><varname>Source=</varname></term>
1195 <listitem>
1196 <para>The source prefix of the route. Possibly followed by
b938cb90 1197 a slash and the prefix length. If omitted, a full-length
798d3a52
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1198 host route is assumed.</para>
1199 </listitem>
1200 </varlistentry>
1201 <varlistentry>
1202 <term><varname>Metric=</varname></term>
1203 <listitem>
b938cb90 1204 <para>The metric of the route (an unsigned integer).</para>
798d3a52
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1205 </listitem>
1206 </varlistentry>
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SS
1207 <varlistentry>
1208 <term><varname>IPv6Preference=</varname></term>
1209 <listitem>
1210 <para>Specifies the route preference as defined in <ulink
1211 url="https://tools.ietf.org/html/rfc4191">RFC4191</ulink> for Router Discovery messages.
1212 Which can be one of <literal>low</literal> the route has a lowest priority,
1213 <literal>medium</literal> the route has a default priority or
1214 <literal>high</literal> the route has a highest priority.</para>
1215 </listitem>
1216 </varlistentry>
769b56a3
TG
1217 <varlistentry>
1218 <term><varname>Scope=</varname></term>
1219 <listitem>
f5c38922
YW
1220 <para>The scope of the route, which can be <literal>global</literal>, <literal>site</literal>,
1221 <literal>link</literal>, <literal>host</literal>, or <literal>nowhere</literal>. For IPv4 route,
1222 defaults to <literal>host</literal> if <varname>Type=</varname> is <literal>local</literal>
1223 or <literal>nat</literal>, and <literal>link</literal> if <varname>Type=</varname> is
1224 <literal>broadcast</literal>, <literal>multicast</literal>, or <literal>anycast</literal>.
1225 In other cases, defaults to <literal>global</literal>.</para>
769b56a3 1226 </listitem>
0d07e595
JK
1227 </varlistentry>
1228 <varlistentry>
1229 <term><varname>PreferredSource=</varname></term>
1230 <listitem>
1231 <para>The preferred source address of the route. The address
1232 must be in the format described in
1233 <citerefentry project='man-pages'><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para>
1234 </listitem>
769b56a3 1235 </varlistentry>
c953b24c 1236 <varlistentry>
f5c38922 1237 <term><varname>Table=</varname></term>
c953b24c 1238 <listitem>
f5c38922
YW
1239 <para>The table identifier for the route. Takes <literal>default</literal>,
1240 <literal>main</literal>, <literal>local</literal> or a number between 1 and 4294967295.
1241 The table can be retrieved using <command>ip route show table <replaceable>num</replaceable></command>.
1242 If unset and <varname>Type=</varname> is <literal>local</literal>, <literal>broadcast</literal>,
1243 <literal>anycast</literal>, or <literal>nat</literal>, then <literal>local</literal> is used.
1244 In other cases, defaults to <literal>main</literal>.
c953b24c
SS
1245 </para>
1246 </listitem>
1247 </varlistentry>
c83ecc04
SS
1248 <varlistentry>
1249 <term><varname>Protocol=</varname></term>
1250 <listitem>
88925d2f 1251 <para>The protocol identifier for the route. Takes a number between 0 and 255 or the special values
ca420b62
YW
1252 <literal>kernel</literal>, <literal>boot</literal>, <literal>static</literal>,
1253 <literal>ra</literal> and <literal>dhcp</literal>. Defaults to <literal>static</literal>.
c83ecc04
SS
1254 </para>
1255 </listitem>
1256 </varlistentry>
983226f3
SS
1257 <varlistentry>
1258 <term><varname>Type=</varname></term>
1259 <listitem>
94d6e299
YW
1260 <para>Specifies the type for the route. Takes one of <literal>unicast</literal>,
1261 <literal>local</literal>, <literal>broadcast</literal>, <literal>anycast</literal>,
1262 <literal>multicast</literal>, <literal>blackhole</literal>, <literal>unreachable</literal>,
1263 <literal>prohibit</literal>, <literal>throw</literal>, <literal>nat</literal>, and
1264 <literal>xresolve</literal>. If <literal>unicast</literal>, a regular route is defined, i.e. a
66d7235e
LP
1265 route indicating the path to take to a destination network address. If <literal>blackhole</literal>, packets
1266 to the defined route are discarded silently. If <literal>unreachable</literal>, packets to the defined route
1267 are discarded and the ICMP message "Host Unreachable" is generated. If <literal>prohibit</literal>, packets
1268 to the defined route are discarded and the ICMP message "Communication Administratively Prohibited" is
1269 generated. If <literal>throw</literal>, route lookup in the current routing table will fail and the route
1270 selection process will return to Routing Policy Database (RPDB). Defaults to <literal>unicast</literal>.
983226f3
SS
1271 </para>
1272 </listitem>
1273 </varlistentry>
323d9329
SS
1274 <varlistentry>
1275 <term><varname>InitialCongestionWindow=</varname></term>
1276 <listitem>
6b21ad33
SS
1277 <para>The TCP initial congestion window is used during the start of a TCP connection. During the start of a TCP
1278 session, when a client requests a resource, the server's initial congestion window determines how many data bytes
1279 will be sent during the initial burst of data. Takes a size in bytes between 1 and 4294967295 (2^32 - 1). The usual
025314d9 1280 suffixes K, M, G are supported and are understood to the base of 1024. When unset, the kernel's default will be used.
323d9329
SS
1281 </para>
1282 </listitem>
1283 </varlistentry>
1284 <varlistentry>
1285 <term><varname>InitialAdvertisedReceiveWindow=</varname></term>
1286 <listitem>
5238e957 1287 <para>The TCP initial advertised receive window is the amount of receive data (in bytes) that can initially be buffered at one time
6b21ad33
SS
1288 on a connection. The sending host can send only that amount of data before waiting for an acknowledgment and window update
1289 from the receiving host. Takes a size in bytes between 1 and 4294967295 (2^32 - 1). The usual suffixes K, M, G are supported
025314d9 1290 and are understood to the base of 1024. When unset, the kernel's default will be used.
323d9329
SS
1291 </para>
1292 </listitem>
1293 </varlistentry>
09f5dfad
SS
1294 <varlistentry>
1295 <term><varname>QuickAck=</varname></term>
1296 <listitem>
9b6ffef3 1297 <para>Takes a boolean. When true enables TCP quick ack mode for the route. When unset, the kernel's default will be used.
09f5dfad
SS
1298 </para>
1299 </listitem>
1300 </varlistentry>
633c7258
SS
1301 <varlistentry>
1302 <term><varname>FastOpenNoCookie=</varname></term>
1303 <listitem>
1304 <para>Takes a boolean. When true enables TCP fastopen without a cookie on a per-route basis.
1305 When unset, the kernel's default will be used.
1306 </para>
1307 </listitem>
09f5dfad 1308 </varlistentry>
9b88f20a
SS
1309 <varlistentry>
1310 <term><varname>TTLPropagate=</varname></term>
1311 <listitem>
1312 <para>Takes a boolean. When true enables TTL propagation at Label Switched Path (LSP) egress.
1313 When unset, the kernel's default will be used.
1314 </para>
1315 </listitem>
1316 </varlistentry>
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1317 <varlistentry>
1318 <term><varname>MTUBytes=</varname></term>
1319 <listitem>
1320 <para>The maximum transmission unit in bytes to set for the
1321 route. The usual suffixes K, M, G, are supported and are
1322 understood to the base of 1024.</para>
1323 <para>Note that if IPv6 is enabled on the interface, and the MTU is chosen
1324 below 1280 (the minimum MTU for IPv6) it will automatically be increased to this value.</para>
1325 </listitem>
afe42aef
SC
1326 </varlistentry>
1327 <varlistentry>
1328 <term><varname>IPServiceType=</varname></term>
1329 <listitem>
e681a2ee
YW
1330 <para>Takes string; <literal>CS6</literal> or <literal>CS4</literal>. Used to set IP
1331 service type to CS6 (network control) or CS4 (Realtime). Defaults to CS6.</para>
afe42aef
SC
1332 </listitem>
1333 </varlistentry>
6ff5cc6b
YW
1334 <varlistentry>
1335 <term><varname>MultiPathRoute=<replaceable>address</replaceable>[@<replaceable>name</replaceable>] [<replaceable>weight</replaceable>]</varname></term>
1336 <listitem>
1337 <para>Configures multipath route. Multipath routing is the technique of using multiple
1338 alternative paths through a network. Takes gateway address. Optionally, takes a network
1339 interface name or index separated with <literal>@</literal>, and a weight in 1..256 for
1340 this multipath route separated with whitespace. This setting can be specified multiple
1341 times. If an empty string is assigned, then the all previous assignments are cleared.</para>
1342 </listitem>
1343 </varlistentry>
798d3a52
ZJS
1344 </variablelist>
1345 </refsect1>
1346
1347 <refsect1>
4f7331a8
YW
1348 <title>[DHCPv4] Section Options</title>
1349 <para>The <literal>[DHCPv4]</literal> section configures the
caa8ca42 1350 DHCPv4 client, if it is enabled with the
ad943783 1351 <varname>DHCP=</varname> setting described above:</para>
798d3a52
ZJS
1352
1353 <variablelist class='network-directives'>
1354 <varlistentry>
1355 <term><varname>UseDNS=</varname></term>
1356 <listitem>
1357 <para>When true (the default), the DNS servers received
1358 from the DHCP server will be used and take precedence over
1359 any statically configured ones.</para>
e88d8021
ZJS
1360
1361 <para>This corresponds to the <option>nameserver</option>
ad943783
LP
1362 option in <citerefentry
1363 project='man-pages'><refentrytitle>resolv.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
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1364 </listitem>
1365 </varlistentry>
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1366 <varlistentry>
1367 <term><varname>RoutesToDNS=</varname></term>
1368 <listitem>
1369 <para>When true, the routes to the DNS servers received from the DHCP server will be
1370 configured. When <varname>UseDNS=</varname> is disabled, this setting is ignored.
f7e7bb65 1371 Defaults to false.</para>
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1372 </listitem>
1373 </varlistentry>
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1374 <varlistentry>
1375 <term><varname>UseNTP=</varname></term>
1376 <listitem>
1377 <para>When true (the default), the NTP servers received
1378 from the DHCP server will be used by systemd-timesyncd
1379 and take precedence over any statically configured ones.</para>
1380 </listitem>
1381 </varlistentry>
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1382 <varlistentry>
1383 <term><varname>UseSIP=</varname></term>
1384 <listitem>
1385 <para>When true (the default), the SIP servers received
1386 from the DHCP server will be saved at the state files and can be
1387 read via <function>sd_network_link_get_sip_servers()</function> function.</para>
1388 </listitem>
1389 </varlistentry>
284e8fd0 1390
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1391 <varlistentry>
1392 <term><varname>UseMTU=</varname></term>
1393 <listitem>
1394 <para>When true, the interface maximum transmission unit
1395 from the DHCP server will be used on the current link.
7169cdc8 1396 If <varname>MTUBytes=</varname> is set, then this setting is ignored.
95ab9eff 1397 Defaults to false.</para>
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1398 </listitem>
1399 </varlistentry>
7585baa0 1400 <varlistentry>
1401 <term><varname>Anonymize=</varname></term>
1402 <listitem>
9b6ffef3 1403 <para>Takes a boolean. When true, the options sent to the DHCP server will
7585baa0 1404 follow the <ulink url="https://tools.ietf.org/html/rfc7844">RFC 7844</ulink>
1405 (Anonymity Profiles for DHCP Clients) to minimize disclosure of identifying information.
1406 Defaults to false.</para>
1407
1408 <para>This option should only be set to true when
1409 <varname>MACAddressPolicy=</varname> is set to <literal>random</literal>
1410 (see <citerefentry
1411 project='man-pages'><refentrytitle>systemd.link</refentrytitle><manvolnum>5</manvolnum></citerefentry>).</para>
1412
1413 <para>Note that this configuration will overwrite others.
1414 In concrete, the following variables will be ignored:
1415 <varname>SendHostname=</varname>, <varname>ClientIdentifier=</varname>,
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1416 <varname>UseRoutes=</varname>, <varname>UseMTU=</varname>,
1417 <varname>VendorClassIdentifier=</varname>, <varname>UseTimezone=</varname>.</para>
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1418
1419 <para>With this option enabled DHCP requests will mimic those generated by Microsoft Windows, in
1420 order to reduce the ability to fingerprint and recognize installations. This means DHCP request
1421 sizes will grow and lease data will be more comprehensive than normally, though most of the
1422 requested data is not actually used.</para>
7585baa0 1423 </listitem>
1424 </varlistentry>
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1425 <varlistentry>
1426 <term><varname>SendHostname=</varname></term>
1427 <listitem>
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1428 <para>When true (the default), the machine's hostname will be sent to the DHCP server.
1429 Note that the machine's hostname must consist only of 7-bit ASCII lower-case characters and
1430 no spaces or dots, and be formatted as a valid DNS domain name. Otherwise, the hostname is not
cad8d671 1431 sent even if this is set to true.</para>
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1432 </listitem>
1433 </varlistentry>
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1434
1435 <varlistentry>
1436 <term><varname>MUDURL=</varname></term>
1437 <listitem>
1438 <para>When configured, the Manufacturer Usage Descriptions (MUD) URL will be sent to the
1439 DHCPv4 server. Takes an URL of length up to 255 characters. A superficial verification that
1440 the string is a valid URL will be performed. DHCPv4 clients are intended to have at most one
1441 MUD URL associated with them. See
1442 <ulink url="https://tools.ietf.org/html/rfc8520">RFC 8520</ulink>.</para>
1443 </listitem>
1444 </varlistentry>
1445
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1446 <varlistentry>
1447 <term><varname>UseHostname=</varname></term>
1448 <listitem>
1449 <para>When true (the default), the hostname received from
31ee3973 1450 the DHCP server will be set as the transient hostname of the system.
d59be2cf 1451 </para>
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1452 </listitem>
1453 </varlistentry>
1adc5d0b 1454 <varlistentry>
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1455 <term><varname>Hostname=</varname></term>
1456 <listitem>
1457 <para>Use this value for the hostname which is sent to the DHCP server, instead of machine's hostname.
1458 Note that the specified hostname must consist only of 7-bit ASCII lower-case characters and
1459 no spaces or dots, and be formatted as a valid DNS domain name.</para>
1460 </listitem>
1461 </varlistentry>
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1462 <varlistentry>
1463 <term><varname>UseDomains=</varname></term>
1464 <listitem>
9b6ffef3 1465 <para>Takes a boolean, or the special value <literal>route</literal>. When true, the domain name
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1466 received from the DHCP server will be used as DNS search domain over this link, similar to the effect of
1467 the <option>Domains=</option> setting. If set to <literal>route</literal>, the domain name received from
1468 the DHCP server will be used for routing DNS queries only, but not for searching, similar to the effect of
1469 the <option>Domains=</option> setting when the argument is prefixed with <literal>~</literal>. Defaults to
1470 false.</para>
1471
1472 <para>It is recommended to enable this option only on trusted networks, as setting this affects resolution
1e7a0e21 1473 of all host names, in particular of single-label names. It is generally safer to use the supplied domain
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1474 only as routing domain, rather than as search domain, in order to not have it affect local resolution of
1475 single-label names.</para>
1476
1477 <para>When set to true, this setting corresponds to the <option>domain</option> option in <citerefentry
1478 project='man-pages'><refentrytitle>resolv.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
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1479 </listitem>
1480 </varlistentry>
1481 <varlistentry>
1482 <term><varname>UseRoutes=</varname></term>
1483 <listitem>
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1484 <para>When true (the default), the static routes will be requested from the DHCP server and added to the
1485 routing table with a metric of 1024, and a scope of "global", "link" or "host", depending on the route's
1486 destination and gateway. If the destination is on the local host, e.g., 127.x.x.x, or the same as the
1487 link's own address, the scope will be set to "host". Otherwise if the gateway is null (a direct route), a
1488 "link" scope will be used. For anything else, scope defaults to "global".</para>
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1489 </listitem>
1490 </varlistentry>
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1491 <varlistentry>
1492 <term><varname>UseGateway=</varname></term>
1493 <listitem>
1494 <para>When true (the default), the gateway will be requested from the DHCP server and added to the
1495 routing table with a metric of 1024, and a scope of "link".</para>
1496 </listitem>
1497 </varlistentry>
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1498 <varlistentry>
1499 <term><varname>UseTimezone=</varname></term>
1500
1501 <listitem><para>When true, the timezone received from the
7f3fdb7f 1502 DHCP server will be set as timezone of the local
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1503 system. Defaults to <literal>no</literal>.</para></listitem>
1504 </varlistentry>
1505
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1506 <varlistentry>
1507 <term><varname>ClientIdentifier=</varname></term>
1508 <listitem>
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1509 <para>The DHCPv4 client identifier to use. Takes one of <literal>mac</literal>, <literal>duid</literal> or <literal>duid-only</literal>.
1510 If set to <literal>mac</literal>, the MAC address of the link is used.
1511 If set to <literal>duid</literal>, an RFC4361-compliant Client ID, which is the combination of IAID and DUID (see below), is used.
1512 If set to <literal>duid-only</literal>, only DUID is used, this may not be RFC compliant, but some setups may require to use this.
1513 Defaults to <literal>duid</literal>.</para>
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1514 </listitem>
1515 </varlistentry>
e2e08e77 1516
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1517 <varlistentry>
1518 <term><varname>VendorClassIdentifier=</varname></term>
1519 <listitem>
1520 <para>The vendor class identifier used to identify vendor
1521 type and configuration.</para>
1522 </listitem>
1523 </varlistentry>
076ea6f6 1524
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1525 <varlistentry>
1526 <term><varname>UserClass=</varname></term>
1527 <listitem>
1528 <para>A DHCPv4 client can use UserClass option to identify the type or category of user or applications
1529 it represents. The information contained in this option is a string that represents the user class of which
1530 the client is a member. Each class sets an identifying string of information to be used by the DHCP
1531 service to classify clients. Takes a whitespace-separated list of strings.</para>
1532 </listitem>
1533 </varlistentry>
1534
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1535 <varlistentry>
1536 <term><varname>MaxAttempts=</varname></term>
1537 <listitem>
1538 <para>Specifies how many times the DHCPv4 client configuration should be attempted. Takes a
1539 number or <literal>infinity</literal>. Defaults to <literal>infinity</literal>.
1540 Note that the time between retries is increased exponentially, so the network will not be
1541 overloaded even if this number is high.</para>
1542 </listitem>
1543 </varlistentry>
1544
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1545 <varlistentry>
1546 <term><varname>DUIDType=</varname></term>
1547 <listitem>
1548 <para>Override the global <varname>DUIDType</varname> setting for this network. See
1549 <citerefentry><refentrytitle>networkd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
1550 for a description of possible values.</para>
1551 </listitem>
1552 </varlistentry>
076ea6f6 1553
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1554 <varlistentry>
1555 <term><varname>DUIDRawData=</varname></term>
1556 <listitem>
1557 <para>Override the global <varname>DUIDRawData</varname> setting for this network. See
1558 <citerefentry><refentrytitle>networkd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
1559 for a description of possible values.</para>
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1560 </listitem>
1561 </varlistentry>
e2e08e77 1562
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1563 <varlistentry>
1564 <term><varname>IAID=</varname></term>
1565 <listitem>
1566 <para>The DHCP Identity Association Identifier (IAID) for the interface, a 32-bit unsigned integer.</para>
1567 </listitem>
1568 </varlistentry>
1569
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1570 <varlistentry>
1571 <term><varname>RequestBroadcast=</varname></term>
1572 <listitem>
1573 <para>Request the server to use broadcast messages before
1574 the IP address has been configured. This is necessary for
1575 devices that cannot receive RAW packets, or that cannot
1576 receive packets at all before an IP address has been
1577 configured. On the other hand, this must not be enabled on
1578 networks where broadcasts are filtered out.</para>
1579 </listitem>
1580 </varlistentry>
e2e08e77 1581
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1582 <varlistentry>
1583 <term><varname>RouteMetric=</varname></term>
1584 <listitem>
1585 <para>Set the routing metric for routes specified by the
1586 DHCP server.</para>
1587 </listitem>
1588 </varlistentry>
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1589
1590 <varlistentry>
1591 <term><varname>RouteTable=<replaceable>num</replaceable></varname></term>
1592 <listitem>
d11e656a 1593 <para>The table identifier for DHCP routes (a number between 1 and 4294967295, or 0 to unset).
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1594 The table can be retrieved using <command>ip route show table <replaceable>num</replaceable></command>.
1595 </para>
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1596 <para>When used in combination with <varname>VRF=</varname> the
1597 VRF's routing table is used unless this parameter is specified.
1598 </para>
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1599 </listitem>
1600 </varlistentry>
9faed222 1601
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1602 <varlistentry>
1603 <term><varname>RouteMTUBytes=</varname></term>
1604 <listitem>
1605 <para>Specifies the MTU for the DHCP routes. Please see the [Route] section for further details.</para>
1606 </listitem>
1607 </varlistentry>
1608
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1609 <varlistentry>
1610 <term><varname>ListenPort=</varname></term>
1611 <listitem>
1612 <para>Allow setting custom port for the DHCP client to listen on.</para>
1613 </listitem>
1614 </varlistentry>
fb5c8216 1615
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1616 <varlistentry>
1617 <term><varname>SendRelease=</varname></term>
1618 <listitem>
1619 <para>When true, the DHCPv4 client sends a DHCP release packet when it stops.
5f3b5f19 1620 Defaults to true.</para>
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1621 </listitem>
1622 </varlistentry>
1623
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1624 <varlistentry>
1625 <term><varname>SendDecline=</varname></term>
1626 <listitem>
86b52a39 1627 <para>A boolean. When <literal>true</literal>, DHCPv4 clients receives IP address from DHCP server.
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1628 After new IP is received, DHCPv4 performs IPv4 Duplicate Address Detection. If duplicate use of IP is detected
1629 the DHCPv4 client rejects the IP by sending a DHCPDECLINE packet DHCP clients try to obtain an IP address again.
1630 See <ulink url="https://tools.ietf.org/html/rfc5227">RFC 5224</ulink>.
1631 Defaults to <literal>unset</literal>.</para>
1632 </listitem>
1633 </varlistentry>
1634
caa8ca42 1635 <varlistentry>
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1636 <term><varname>BlackList=</varname></term>
1637 <listitem>
1638 <para>A whitespace-separated list of IPv4 addresses. DHCP offers from servers in the list are rejected.</para>
1639 </listitem>
1640 </varlistentry>
1641
1642 <varlistentry>
1643 <term><varname>RequestOptions=</varname></term>
caa8ca42 1644 <listitem>
5bc945be 1645 <para>A whitespace-separated list of integers in the range 1–254.</para>
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1646 </listitem>
1647 </varlistentry>
1648
cb29c156 1649 <varlistentry>
864edb39 1650 <term><varname>SendOption=</varname></term>
cb29c156 1651 <listitem>
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1652 <para>Send an arbitrary raw option in the DHCPv4 request. Takes a DHCP option number, data type
1653 and data separated with a colon
1654 (<literal><replaceable>option</replaceable>:<replaceable>type</replaceable>:<replaceable>value</replaceable></literal>).
1655 The option number must be an integer in the range 1..254. The type takes one of <literal>uint8</literal>,
1656 <literal>uint16</literal>, <literal>uint32</literal>, <literal>ipv4address</literal>, or
1657 <literal>string</literal>. Special characters in the data string may be escaped using
1658 <ulink url="https://en.wikipedia.org/wiki/Escape_sequences_in_C#Table_of_escape_sequences">C-style
1659 escapes</ulink>. This setting can be specified multiple times. If an empty string is specified,
1660 then all options specified earlier are cleared. Defaults to unset.</para>
1661 </listitem>
1662 </varlistentry>
1663
1664 <varlistentry>
1665 <term><varname>SendVendorOption=</varname></term>
1666 <listitem>
1667 <para>Send an arbitrary vendor option in the DHCPv4 request. Takes a DHCP option number, data type
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1668 and data separated with a colon
1669 (<literal><replaceable>option</replaceable>:<replaceable>type</replaceable>:<replaceable>value</replaceable></literal>).
11fcfc53 1670 The option number must be an integer in the range 1..254. The type takes one of <literal>uint8</literal>,
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1671 <literal>uint16</literal>, <literal>uint32</literal>, <literal>ipv4address</literal>, or
1672 <literal>string</literal>. Special characters in the data string may be escaped using
a2cc708a 1673 <ulink url="https://en.wikipedia.org/wiki/Escape_sequences_in_C#Table_of_escape_sequences">C-style
d8b736bd 1674 escapes</ulink>. This setting can be specified multiple times. If an empty string is specified,
a2cc708a 1675 then all options specified earlier are cleared. Defaults to unset.</para>
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1676 </listitem>
1677 </varlistentry>
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1678 </variablelist>
1679 </refsect1>
1680
1681 <refsect1>
1682 <title>[DHCPv6] Section Options</title>
1683 <para>The <literal>[DHCPv6]</literal> section configures the DHCPv6 client, if it is enabled with the
4f7331a8 1684 <varname>DHCP=</varname> setting described above, or invoked by the IPv6 Router Advertisement:</para>
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1685
1686 <variablelist class='network-directives'>
1687 <varlistentry>
1688 <term><varname>UseDNS=</varname></term>
1689 <term><varname>UseNTP=</varname></term>
1690 <listitem>
9fdae8d5 1691 <para>As in the <literal>[DHCPv4]</literal> section.</para>
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1692 </listitem>
1693 </varlistentry>
1694
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1695 <varlistentry>
1696 <term><varname>RapidCommit=</varname></term>
1697 <listitem>
9b6ffef3 1698 <para>Takes a boolean. The DHCPv6 client can obtain configuration parameters from a DHCPv6 server through
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1699 a rapid two-message exchange (solicit and reply). When the rapid commit option is enabled by both
1700 the DHCPv6 client and the DHCPv6 server, the two-message exchange is used, rather than the default
1701 four-method exchange (solicit, advertise, request, and reply). The two-message exchange provides
1702 faster client configuration and is beneficial in environments in which networks are under a heavy load.
1703 See <ulink url="https://tools.ietf.org/html/rfc3315#section-17.2.1">RFC 3315</ulink> for details.
1704 Defaults to true.</para>
1705 </listitem>
1706 </varlistentry>
1707
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1708 <varlistentry>
1709 <term><varname>MUDURL=</varname></term>
1710 <listitem>
1711 <para>When configured, the Manufacturer Usage Descriptions (MUD) URL will be sent to the DHCPV6 server.
1712 Takes an URL of length up to 255 characters. A superficial verification that the string is a valid URL
1713 will be performed. DHCPv6 clients are intended to have at most one MUD URL associated with them. See
1714 <ulink url="https://tools.ietf.org/html/rfc8520">RFC 8520</ulink>.</para>
1715 </listitem>
1716 </varlistentry>
1717
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1718 <varlistentry>
1719 <term><varname>ForceDHCPv6PDOtherInformation=</varname></term>
1720 <listitem>
9b6ffef3 1721 <para>Takes a boolean that enforces DHCPv6 stateful mode when the 'Other information' bit is set in
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1722 Router Advertisement messages. By default setting only the 'O' bit in Router Advertisements
1723 makes DHCPv6 request network information in a stateless manner using a two-message Information
1724 Request and Information Reply message exchange.
1725 <ulink url="https://tools.ietf.org/html/rfc7084">RFC 7084</ulink>, requirement WPD-4, updates
1726 this behavior for a Customer Edge router so that stateful DHCPv6 Prefix Delegation is also
1727 requested when only the 'O' bit is set in Router Advertisements. This option enables such a CE
1728 behavior as it is impossible to automatically distinguish the intention of the 'O' bit otherwise.
1729 By default this option is set to 'false', enable it if no prefixes are delegated when the device
1730 should be acting as a CE router.</para>
1731 </listitem>
1732 </varlistentry>
1733
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1734 <varlistentry>
1735 <term><varname>PrefixDelegationHint=</varname></term>
1736 <listitem>
48daf510 1737 <para>Takes an IPv6 address with prefix length as <varname>Address=</varname> in
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1738 the "[Network]" section. Specifies the DHCPv6 client for the requesting router to include
1739 a prefix-hint in the DHCPv6 solicitation. Prefix ranges 1-128. Defaults to unset.</para>
1740 </listitem>
1741 </varlistentry>
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1742
1743 <varlistentry>
1744 <term><varname>WithoutRA=</varname></term>
1745 <listitem>
1746 <para>When true, DHCPv6 client starts without router advertisements's managed or other address configuration flag.
1747 Defaults to false.</para>
1748 </listitem>
1749 </varlistentry>
ad943783 1750 </variablelist>
caa8ca42 1751 </refsect1>
413708d1 1752
1e7a0e21 1753 <refsect1>
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1754 <title>[IPv6AcceptRA] Section Options</title>
1755 <para>The <literal>[IPv6AcceptRA]</literal> section configures the IPv6 Router Advertisement
1756 (RA) client, if it is enabled with the <varname>IPv6AcceptRA=</varname> setting described
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1757 above:</para>
1758
1759 <variablelist class='network-directives'>
1760 <varlistentry>
1761 <term><varname>UseDNS=</varname></term>
1762 <listitem>
1763 <para>When true (the default), the DNS servers received in the Router Advertisement will be used and take
1764 precedence over any statically configured ones.</para>
1765
1766 <para>This corresponds to the <option>nameserver</option> option in <citerefentry
1767 project='man-pages'><refentrytitle>resolv.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
1768 </listitem>
1769 </varlistentry>
1770
1771 <varlistentry>
1772 <term><varname>UseDomains=</varname></term>
1773 <listitem>
9b6ffef3 1774 <para>Takes a boolean, or the special value <literal>route</literal>. When true, the domain name
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1775 received via IPv6 Router Advertisement (RA) will be used as DNS search domain over this link, similar to
1776 the effect of the <option>Domains=</option> setting. If set to <literal>route</literal>, the domain name
1777 received via IPv6 RA will be used for routing DNS queries only, but not for searching, similar to the
1778 effect of the <option>Domains=</option> setting when the argument is prefixed with
1779 <literal>~</literal>. Defaults to false.</para>
1780
1781 <para>It is recommended to enable this option only on trusted networks, as setting this affects resolution
1782 of all host names, in particular of single-label names. It is generally safer to use the supplied domain
1783 only as routing domain, rather than as search domain, in order to not have it affect local resolution of
1784 single-label names.</para>
1785
1786 <para>When set to true, this setting corresponds to the <option>domain</option> option in <citerefentry
1787 project='man-pages'><refentrytitle>resolv.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
1788 </listitem>
1789 </varlistentry>
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1790
1791 <varlistentry>
1792 <term><varname>RouteTable=<replaceable>num</replaceable></varname></term>
1793 <listitem>
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1794 <para>The table identifier for the routes received in the Router Advertisement
1795 (a number between 1 and 4294967295, or 0 to unset).
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1796 The table can be retrieved using <command>ip route show table <replaceable>num</replaceable></command>.
1797 </para>
1798 </listitem>
1799 </varlistentry>
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1800
1801 <varlistentry>
1802 <term><varname>UseAutonomousPrefix=</varname></term>
1803 <listitem>
1804 <para>When true (the default), the autonomous prefix received in the Router Advertisement will be used and take
1805 precedence over any statically configured ones.</para>
1806 </listitem>
1807 </varlistentry>
1808
1809 <varlistentry>
1810 <term><varname>UseOnLinkPrefix=</varname></term>
1811 <listitem>
1812 <para>When true (the default), the onlink prefix received in the Router Advertisement will be used and take
1813 precedence over any statically configured ones.</para>
1814 </listitem>
1815 </varlistentry>
1816
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1817 <varlistentry>
1818 <term><varname>BlackList=</varname></term>
1819 <listitem>
1820 <para>A whitespace-separated list of IPv6 prefixes. IPv6 prefixes supplied via router advertisements in the list are ignored.</para>
1821 </listitem>
1822 </varlistentry>
1823
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1824 <varlistentry>
1825 <term><varname>DHCPv6Client=</varname></term>
1826 <listitem>
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1827 <para>Takes a boolean, or the special value <literal>always</literal>. When true (the default), the DHCPv6 client will be started when the
1828 RA has the managed or other information flag. If set to <literal>always</literal>, the DHCPv6 client will be started even if there is no
1829 managed or other information flag in the RA.</para>
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1830 </listitem>
1831 </varlistentry>
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1832 </variablelist>
1833 </refsect1>
1834
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1835 <refsect1>
1836 <title>[DHCPServer] Section Options</title>
1837 <para>The <literal>[DHCPServer]</literal> section contains
1838 settings for the DHCP server, if enabled via the
1839 <varname>DHCPServer=</varname> option described above:</para>
1840
1841 <variablelist class='network-directives'>
1842
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1843 <varlistentry>
1844 <term><varname>PoolOffset=</varname></term>
1845 <term><varname>PoolSize=</varname></term>
1846
1847 <listitem><para>Configures the pool of addresses to hand out. The pool
1848 is a contiguous sequence of IP addresses in the subnet configured for
1849 the server address, which does not include the subnet nor the broadcast
1850 address. <varname>PoolOffset=</varname> takes the offset of the pool
1851 from the start of subnet, or zero to use the default value.
1852 <varname>PoolSize=</varname> takes the number of IP addresses in the
b938cb90 1853 pool or zero to use the default value. By default, the pool starts at
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1854 the first address after the subnet address and takes up the rest of
1855 the subnet, excluding the broadcast address. If the pool includes
1856 the server address (the default), this is reserved and not handed
1857 out to clients.</para></listitem>
1858 </varlistentry>
1859
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1860 <varlistentry>
1861 <term><varname>DefaultLeaseTimeSec=</varname></term>
1862 <term><varname>MaxLeaseTimeSec=</varname></term>
1863
1864 <listitem><para>Control the default and maximum DHCP lease
1865 time to pass to clients. These settings take time values in seconds or
1866 another common time unit, depending on the suffix. The default
1867 lease time is used for clients that did not ask for a specific
1868 lease time. If a client asks for a lease time longer than the
b938cb90 1869 maximum lease time, it is automatically shortened to the
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1870 specified time. The default lease time defaults to 1h, the
1871 maximum lease time to 12h. Shorter lease times are beneficial
1872 if the configuration data in DHCP leases changes frequently
1873 and clients shall learn the new settings with shorter
1874 latencies. Longer lease times reduce the generated DHCP
1875 network traffic.</para></listitem>
1876 </varlistentry>
1877
1878 <varlistentry>
1879 <term><varname>EmitDNS=</varname></term>
1880 <term><varname>DNS=</varname></term>
1881
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1882 <listitem><para>Takes a boolean. Configures whether the DHCP leases handed out
1883 to clients shall contain DNS server information. Defaults to <literal>yes</literal>.
1884 The DNS servers to pass to clients may be configured with the
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1885 <varname>DNS=</varname> option, which takes a list of IPv4
1886 addresses. If the <varname>EmitDNS=</varname> option is
b938cb90 1887 enabled but no servers configured, the servers are
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1888 automatically propagated from an "uplink" interface that has
1889 appropriate servers set. The "uplink" interface is determined
1890 by the default route of the system with the highest
1891 priority. Note that this information is acquired at the time
1892 the lease is handed out, and does not take uplink interfaces
1893 into account that acquire DNS or NTP server information at a
1894 later point. DNS server propagation does not take
1895 <filename>/etc/resolv.conf</filename> into account. Also, note
a8eaaee7 1896 that the leases are not refreshed if the uplink network
ad943783 1897 configuration changes. To ensure clients regularly acquire the
b938cb90 1898 most current uplink DNS server information, it is thus
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1899 advisable to shorten the DHCP lease time via
1900 <varname>MaxLeaseTimeSec=</varname> described
1901 above.</para></listitem>
1902 </varlistentry>
1903
1904 <varlistentry>
1905 <term><varname>EmitNTP=</varname></term>
1906 <term><varname>NTP=</varname></term>
1907
1908 <listitem><para>Similar to the <varname>EmitDNS=</varname> and
b938cb90 1909 <varname>DNS=</varname> settings described above, these
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1910 settings configure whether and what NTP server information
1911 shall be emitted as part of the DHCP lease. The same syntax,
1912 propagation semantics and defaults apply as for
1913 <varname>EmitDNS=</varname> and
1914 <varname>DNS=</varname>.</para></listitem>
1915 </varlistentry>
1916
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1917 <varlistentry>
1918 <term><varname>EmitSIP=</varname></term>
1919 <term><varname>SIP=</varname></term>
1920
1921 <listitem><para>Similar to the <varname>EmitDNS=</varname> and
1922 <varname>DNS=</varname> settings described above, these
1923 settings configure whether and what SIP server information
1924 shall be emitted as part of the DHCP lease. The same syntax,
1925 propagation semantics and defaults apply as for
1926 <varname>EmitDNS=</varname> and
1927 <varname>DNS=</varname>.</para></listitem>
1928 </varlistentry>
1929
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1930 <varlistentry>
1931 <term><varname>POP3Servers=</varname></term>
1932
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1933 <listitem><para>Similar to the <varname>DNS=</varname> setting described above, this setting
1934 configures whether and what POP3 server information shall be emitted as part of the DHCP lease. The
1935 same syntax, propagation semantics and defaults apply as for
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1936 <varname>DNS=</varname>.</para></listitem>
1937 </varlistentry>
1938
1939 <varlistentry>
1940 <term><varname>SMTPServers=</varname></term>
1941
1942 <listitem><para>Similar to the <varname>DNS=</varname> setting described above, this
1943 setting configures whether and what SMTP server information shall be emitted as part of
1944 the DHCP lease. The same syntax, propagation semantics and defaults apply as for
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1945 <varname>DNS=</varname>.</para></listitem>
1946 </varlistentry>
1947
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1948 <varlistentry>
1949 <term><varname>EmitRouter=</varname></term>
1950
1951 <listitem><para>Similar to the <varname>EmitDNS=</varname>
1952 setting described above, this setting configures whether the
1953 DHCP lease should contain the router option. The same syntax,
1954 propagation semantics and defaults apply as for
1955 <varname>EmitDNS=</varname>.</para></listitem>
1956 </varlistentry>
1957
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1958 <varlistentry>
1959 <term><varname>EmitTimezone=</varname></term>
1960 <term><varname>Timezone=</varname></term>
1961
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1962 <listitem><para>Takes a boolean. Configures whether the DHCP leases handed out
1963 to clients shall contain timezone information. Defaults to <literal>yes</literal>. The
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1964 <varname>Timezone=</varname> setting takes a timezone string
1965 (such as <literal>Europe/Berlin</literal> or
1966 <literal>UTC</literal>) to pass to clients. If no explicit
b938cb90 1967 timezone is set, the system timezone of the local host is
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1968 propagated, as determined by the
1969 <filename>/etc/localtime</filename> symlink.</para></listitem>
1970 </varlistentry>
1971
564ca984 1972 <varlistentry>
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1973 <term><varname>SendOption=</varname></term>
1974 <listitem>
1975 <para>Send a raw option with value via DHCPv4 server. Takes a DHCP option number, data type
1976 and data (<literal><replaceable>option</replaceable>:<replaceable>type</replaceable>:<replaceable>value</replaceable></literal>).
1977 The option number is an integer in the range 1..254. The type takes one of <literal>uint8</literal>,
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1978 <literal>uint16</literal>, <literal>uint32</literal>, <literal>ipv4address</literal>, or
1979 <literal>string</literal>. Special characters in the data string may be escaped using
1980 <ulink url="https://en.wikipedia.org/wiki/Escape_sequences_in_C#Table_of_escape_sequences">C-style
1981 escapes</ulink>. This setting can be specified multiple times. If an empty string is specified,
1982 then all options specified earlier are cleared. Defaults to unset.</para>
1983 </listitem>
1984 </varlistentry>
1985
1986 <varlistentry>
1987 <term><varname>SendVendorOption=</varname></term>
1988 <listitem>
1989 <para>Send a vendor option with value via DHCPv4 server. Takes a DHCP option number, data type
1990 and data (<literal><replaceable>option</replaceable>:<replaceable>type</replaceable>:<replaceable>value</replaceable></literal>).
1991 The option number is an integer in the range 1..254. The type takes one of <literal>uint8</literal>,
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1992 <literal>uint16</literal>, <literal>uint32</literal>, <literal>ipv4address</literal>, or
1993 <literal>string</literal>. Special characters in the data string may be escaped using
1994 <ulink url="https://en.wikipedia.org/wiki/Escape_sequences_in_C#Table_of_escape_sequences">C-style
1995 escapes</ulink>. This setting can be specified multiple times. If an empty string is specified,
1996 then all options specified earlier are cleared. Defaults to unset.</para>
1997 </listitem>
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1998 </varlistentry>
1999
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2000 </variablelist>
2001 </refsect1>
2002
798d3a52 2003 <refsect1>
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2004 <title>[IPv6PrefixDelegation] Section Options</title>
2005 <para>The <literal>[IPv6PrefixDelegation]</literal> section contains
2006 settings for sending IPv6 Router Advertisements and whether to act as
2007 a router, if enabled via the <varname>IPv6PrefixDelegation=</varname>
2008 option described above. IPv6 network prefixes are defined with one or
2009 more <literal>[IPv6Prefix]</literal> sections.</para>
2010
2011 <variablelist class='network-directives'>
2012
2013 <varlistentry>
2014 <term><varname>Managed=</varname></term>
2015 <term><varname>OtherInformation=</varname></term>
2016
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2017 <listitem><para>Takes a boolean. Controls whether a DHCPv6 server is used to acquire IPv6
2018 addresses on the network link when <varname>Managed=</varname>
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2019 is set to <literal>true</literal> or if only additional network
2020 information can be obtained via DHCPv6 for the network link when
9b6ffef3 2021 <varname>OtherInformation=</varname> is set to
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2022 <literal>true</literal>. Both settings default to
2023 <literal>false</literal>, which means that a DHCPv6 server is not being
2024 used.</para></listitem>
2025 </varlistentry>
2026
2027 <varlistentry>
2028 <term><varname>RouterLifetimeSec=</varname></term>
2029
9b6ffef3 2030 <listitem><para>Takes a timespan. Configures the IPv6 router lifetime in seconds. If set,
3f9e0236 2031 this host also announces itself in Router Advertisements as an IPv6
025314d9 2032 router for the network link. When unset, the host is not acting as a router.</para>
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2033 </listitem>
2034 </varlistentry>
2035
2036 <varlistentry>
2037 <term><varname>RouterPreference=</varname></term>
2038
2039 <listitem><para>Configures IPv6 router preference if
2040 <varname>RouterLifetimeSec=</varname> is non-zero. Valid values are
2041 <literal>high</literal>, <literal>medium</literal> and
2042 <literal>low</literal>, with <literal>normal</literal> and
2043 <literal>default</literal> added as synonyms for
2044 <literal>medium</literal> just to make configuration easier. See
2045 <ulink url="https://tools.ietf.org/html/rfc4191">RFC 4191</ulink>
2046 for details. Defaults to <literal>medium</literal>.</para></listitem>
2047 </varlistentry>
2048
2049 <varlistentry>
4cb8478c 2050 <term><varname>EmitDNS=</varname></term>
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2051 <term><varname>DNS=</varname></term>
2052
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2053 <listitem><para><varname>DNS=</varname> specifies a list of recursive DNS server IPv6 addresses
2054 that are distributed via Router Advertisement messages when <varname>EmitDNS=</varname> is
2055 true. <varname>DNS=</varname> also takes special value <literal>_link_local</literal>; in that
2056 case the IPv6 link local address is distributed. If <varname>DNS=</varname> is empty, DNS
2057 servers are read from the <literal>[Network]</literal> section. If the
2058 <literal>[Network]</literal> section does not contain any DNS servers either, DNS servers from
2059 the uplink with the highest priority default route are used. When <varname>EmitDNS=</varname>
2060 is false, no DNS server information is sent in Router Advertisement messages.
4cb8478c 2061 <varname>EmitDNS=</varname> defaults to true.
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2062 </para></listitem>
2063 </varlistentry>
2064
760021c0 2065 <varlistentry>
4cb8478c 2066 <term><varname>EmitDomains=</varname></term>
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2067 <term><varname>Domains=</varname></term>
2068
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2069 <listitem><para>A list of DNS search domains distributed via Router
2070 Advertisement messages when <varname>EmitDomains=</varname> is true. If
2071 <varname>Domains=</varname> is empty, DNS search domains are read from the
2072 <literal>[Network]</literal> section. If the <literal>[Network]</literal>
2073 section does not contain any DNS search domains either, DNS search
2074 domains from the uplink with the highest priority default route are
2075 used. When <varname>EmitDomains=</varname> is false, no DNS search domain
2076 information is sent in Router Advertisement messages.
2077 <varname>EmitDomains=</varname> defaults to true.
2078 </para></listitem>
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2079 </varlistentry>
2080
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2081 <varlistentry>
2082 <term><varname>DNSLifetimeSec=</varname></term>
2083
2084 <listitem><para>Lifetime in seconds for the DNS server addresses listed
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2085 in <varname>DNS=</varname> and search domains listed in
2086 <varname>Domains=</varname>.</para></listitem>
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2087 </varlistentry>
2088
2089 </variablelist>
2090 </refsect1>
2091
203d4df5 2092 <refsect1>
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2093 <title>[IPv6Prefix] Section Options</title>
2094 <para>One or more <literal>[IPv6Prefix]</literal> sections contain the IPv6
2095 prefixes that are announced via Router Advertisements. See
2096 <ulink url="https://tools.ietf.org/html/rfc4861">RFC 4861</ulink>
2097 for further details.</para>
2098
2099 <variablelist class='network-directives'>
2100
2101 <varlistentry>
2102 <term><varname>AddressAutoconfiguration=</varname></term>
2103 <term><varname>OnLink=</varname></term>
2104
9b6ffef3 2105 <listitem><para>Takes a boolean to specify whether IPv6 addresses can be
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2106 autoconfigured with this prefix and whether the prefix can be used for
2107 onlink determination. Both settings default to <literal>true</literal>
2108 in order to ease configuration.
2109 </para></listitem>
2110 </varlistentry>
2111
2112 <varlistentry>
2113 <term><varname>Prefix=</varname></term>
2114
2115 <listitem><para>The IPv6 prefix that is to be distributed to hosts.
2116 Similarly to configuring static IPv6 addresses, the setting is
2117 configured as an IPv6 prefix and its prefix length, separated by a
2118 <literal>/</literal> character. Use multiple
2119 <literal>[IPv6Prefix]</literal> sections to configure multiple IPv6
2120 prefixes since prefix lifetimes, address autoconfiguration and onlink
2121 status may differ from one prefix to another.</para></listitem>
2122 </varlistentry>
2123
2124 <varlistentry>
2125 <term><varname>PreferredLifetimeSec=</varname></term>
2126 <term><varname>ValidLifetimeSec=</varname></term>
2127
2128 <listitem><para>Preferred and valid lifetimes for the prefix measured in
2129 seconds. <varname>PreferredLifetimeSec=</varname> defaults to 604800
2130 seconds (one week) and <varname>ValidLifetimeSec=</varname> defaults
2131 to 2592000 seconds (30 days).</para></listitem>
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2132 </varlistentry>
2133
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2134 <varlistentry>
2135 <term><varname>Assign=</varname></term>
2136 <listitem><para>Takes a boolean. When true, adds an address from the prefix. Default to false.
2137 </para></listitem>
2138 </varlistentry>
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2139 </variablelist>
2140 </refsect1>
2141
2142 <refsect1>
2143 <title>[IPv6RoutePrefix] Section Options</title>
2144 <para>One or more <literal>[IPv6RoutePrefix]</literal> sections contain the IPv6
2145 prefix routes that are announced via Router Advertisements. See
2146 <ulink url="https://tools.ietf.org/html/rfc4191">RFC 4191</ulink>
2147 for further details.</para>
2148
2149 <variablelist class='network-directives'>
2150
2151 <varlistentry>
2152 <term><varname>Route=</varname></term>
2153
2154 <listitem><para>The IPv6 route that is to be distributed to hosts.
2155 Similarly to configuring static IPv6 routes, the setting is
2156 configured as an IPv6 prefix routes and its prefix route length,
2157 separated by a<literal>/</literal> character. Use multiple
2158 <literal>[IPv6PrefixRoutes]</literal> sections to configure multiple IPv6
2159 prefix routes.</para></listitem>
2160 </varlistentry>
2161
2162 <varlistentry>
2163 <term><varname>LifetimeSec=</varname></term>
2164
2165 <listitem><para>Lifetime for the route prefix measured in
2166 seconds. <varname>LifetimeSec=</varname> defaults to 604800 seconds (one week).
2167 </para></listitem>
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2168 </varlistentry>
2169
2170 </variablelist>
2171 </refsect1>
2172
2173 <refsect1>
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2174 <title>[Bridge] Section Options</title>
2175 <para>The <literal>[Bridge]</literal> section accepts the
2176 following keys.</para>
2177 <variablelist class='network-directives'>
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2178 <varlistentry>
2179 <term><varname>UnicastFlood=</varname></term>
2180 <listitem>
9b6ffef3 2181 <para>Takes a boolean. Controls whether the bridge should flood
072f9e4a 2182 traffic for which an FDB entry is missing and the destination
025314d9 2183 is unknown through this port. When unset, the kernel's default will be used.
47c7dfe2 2184 </para>
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2185 </listitem>
2186 </varlistentry>
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2187 <varlistentry>
2188 <term><varname>MulticastFlood=</varname></term>
2189 <listitem>
2190 <para>Takes a boolean. Controls whether the bridge should flood
2191 traffic for which an MDB entry is missing and the destination
2192 is unknown through this port. When unset, the kernel's default will be used.
2193 </para>
2194 </listitem>
2195 </varlistentry>
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2196 <varlistentry>
2197 <term><varname>MulticastToUnicast=</varname></term>
2198 <listitem>
2199 <para>Takes a boolean. Multicast to unicast works on top of the multicast snooping feature of
2200 the bridge. Which means unicast copies are only delivered to hosts which are interested in it.
2201 When unset, the kernel's default will be used.
2202 </para>
2203 </listitem>
2204 </varlistentry>
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2205 <varlistentry>
2206 <term><varname>NeighborSuppression=</varname></term>
2207 <listitem>
2208 <para>Takes a boolean. Configures whether ARP and ND neighbor suppression is enabled for
2209 this port. When unset, the kernel's default will be used.
2210 </para>
2211 </listitem>
2212 </varlistentry>
2213 <varlistentry>
2214 <term><varname>Learning=</varname></term>
2215 <listitem>
2216 <para>Takes a boolean. Configures whether MAC address learning is enabled for
2217 this port. When unset, the kernel's default will be used.
2218 </para>
2219 </listitem>
2220 </varlistentry>
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2221 <varlistentry>
2222 <term><varname>HairPin=</varname></term>
2223 <listitem>
9b6ffef3 2224 <para>Takes a boolean. Configures whether traffic may be sent back
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2225 out of the port on which it was received. When this flag is false, and the bridge
2226 will not forward traffic back out of the receiving port.
2227 When unset, the kernel's default will be used.</para>
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2228 </listitem>
2229 </varlistentry>
2230 <varlistentry>
84c34096 2231 <term><varname>UseBPDU=</varname></term>
165c41a9 2232 <listitem>
9b6ffef3 2233 <para>Takes a boolean. Configures whether STP Bridge Protocol Data Units will be
025314d9 2234 processed by the bridge port. When unset, the kernel's default will be used.</para>
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2235 </listitem>
2236 </varlistentry>
2237 <varlistentry>
2238 <term><varname>FastLeave=</varname></term>
2239 <listitem>
9b6ffef3 2240 <para>Takes a boolean. This flag allows the bridge to immediately stop multicast
a8eaaee7 2241 traffic on a port that receives an IGMP Leave message. It is only used with
025314d9 2242 IGMP snooping if enabled on the bridge. When unset, the kernel's default will be used.</para>
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2243 </listitem>
2244 </varlistentry>
2245 <varlistentry>
23da66bb 2246 <term><varname>AllowPortToBeRoot=</varname></term>
165c41a9 2247 <listitem>
9b6ffef3 2248 <para>Takes a boolean. Configures whether a given port is allowed to
47c7dfe2 2249 become a root port. Only used when STP is enabled on the bridge.
025314d9 2250 When unset, the kernel's default will be used.</para>
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2251 </listitem>
2252 </varlistentry>
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2253 <varlistentry>
2254 <term><varname>ProxyARP=</varname></term>
2255 <listitem>
2256 <para>Takes a boolean. Configures whether proxy ARP to be enabled on this port.
2257 When unset, the kernel's default will be used.</para>
2258 </listitem>
2259 </varlistentry>
2260 <varlistentry>
2261 <term><varname>ProxyARPWiFi=</varname></term>
2262 <listitem>
2263 <para>Takes a boolean. Configures whether proxy ARP to be enabled on this port
2264 which meets extended requirements by IEEE 802.11 and Hotspot 2.0 specifications.
2265 When unset, the kernel's default will be used.</para>
2266 </listitem>
2267 </varlistentry>
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2268 <varlistentry>
2269 <term><varname>MulticastRouter=</varname></term>
2270 <listitem>
2271 <para>Configures this port for having multicast routers attached. A port with a multicast
2272 router will receive all multicast traffic. Takes one of <literal>no</literal>
2273 to disable multicast routers on this port, <literal>query</literal> to let the system detect
2274 the presence of routers, <literal>permanent</literal> to permanently enable multicast traffic
2275 forwarding on this port, or <literal>temporary</literal> to enable multicast routers temporarily
2276 on this port, not depending on incoming queries. When unset, the kernel's default will be used.</para>
2277 </listitem>
2278 </varlistentry>
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2279 <varlistentry>
2280 <term><varname>Cost=</varname></term>
2281 <listitem>
47c7dfe2 2282 <para>Sets the "cost" of sending packets of this interface.
a8eaaee7 2283 Each port in a bridge may have a different speed and the cost
798d3a52 2284 is used to decide which link to use. Faster interfaces
785889e5 2285 should have lower costs. It is an integer value between 1 and
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2286 65535.</para>
2287 </listitem>
2288 </varlistentry>
2289 <varlistentry>
2290 <term><varname>Priority=</varname></term>
2291 <listitem>
2292 <para>Sets the "priority" of sending packets on this interface.
2293 Each port in a bridge may have a different priority which is used
2294 to decide which link to use. Lower value means higher priority.
785889e5 2295 It is an integer value between 0 to 63. Networkd does not set any
b56be296 2296 default, meaning the kernel default value of 32 is used.</para>
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2297 </listitem>
2298 </varlistentry>
2299 </variablelist>
2300 </refsect1>
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2301 <refsect1>
2302 <title>[BridgeFDB] Section Options</title>
2303 <para>The <literal>[BridgeFDB]</literal> section manages the
2304 forwarding database table of a port and accepts the following
2305 keys. Specify several <literal>[BridgeFDB]</literal> sections to
2306 configure several static MAC table entries.</para>
2307
2308 <variablelist class='network-directives'>
2309 <varlistentry>
2310 <term><varname>MACAddress=</varname></term>
2311 <listitem>
2312 <para>As in the <literal>[Network]</literal> section. This
2313 key is mandatory.</para>
2314 </listitem>
2315 </varlistentry>
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SS
2316 <varlistentry>
2317 <term><varname>Destination=</varname></term>
2318 <listitem>
2319 <para>Takes an IP address of the destination VXLAN tunnel endpoint.</para>
2320 </listitem>
2321 </varlistentry>
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2322 <varlistentry>
2323 <term><varname>VLANId=</varname></term>
2324 <listitem>
a8eaaee7 2325 <para>The VLAN ID for the new static MAC table entry. If
db9b9fb9 2326 omitted, no VLAN ID information is appended to the new static MAC
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2327 table entry.</para>
2328 </listitem>
2329 </varlistentry>
61b824c5
SS
2330 <varlistentry>
2331 <term><varname>VNI=</varname></term>
2332 <listitem>
2333 <para>The VXLAN Network Identifier (or VXLAN Segment ID) to use to connect to
2334 the remote VXLAN tunnel endpoint. Takes a number in the range 1-16777215.
2335 Defaults to unset.</para>
2336 </listitem>
2337 </varlistentry>
bdb397ed
SS
2338 <varlistentry>
2339 <term><varname>AssociatedWith=</varname></term>
2340 <listitem>
2341 <para>Specifies where the address is associated with. Takes one of <literal>use</literal>,
2342 <literal>self</literal>, <literal>master</literal> or <literal>router</literal>.
2343 <literal>use</literal> means the address is in use. User space can use this option to
2344 indicate to the kernel that the fdb entry is in use. <literal>self</literal> means
2345 the address is associated with the port drivers fdb. Usually hardware. <literal>master</literal>
2346 means the address is associated with master devices fdb. <literal>router</literal> means
2347 the destination address is associated with a router. Note that it's valid if the referenced
2348 device is a VXLAN type device and has route shortcircuit enabled. Defaults to <literal>self</literal>.</para>
2349 </listitem>
2350 </varlistentry>
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2351 </variablelist>
2352 </refsect1>
06828bb6 2353
e9a8c550
SS
2354 <refsect1>
2355 <title>[LLDP] Section Options</title>
2356 <para>The <literal>[LLDP]</literal> section manages the Link Layer Discovery Protocol (LLDP) and accepts the
2357 following keys.</para>
2358 <variablelist class='network-directives'>
2359 <varlistentry>
2360 <term><varname>MUDURL=</varname></term>
2361 <listitem>
2362 <para>Controls support for Ethernet LLDP packet's Manufacturer Usage Description (MUD). MUD is an embedded software
2363 standard defined by the IETF that allows IoT Device makers to advertise device specifications, including the intended
2364 communication patterns for their device when it connects to the network. The network can then use this intent to author
2365 a context-specific access policy, so the device functions only within those parameters. Takes an URL of length up to 255
2366 characters. A superficial verification that the string is a valid URL
2367 will be performed. See
2368 <ulink url="https://tools.ietf.org/html/rfc8520">RFC 8520</ulink> for details. The MUD URL received
2369 from the LLDP packets will be saved at the state files and can be read via
2370 <function>sd_lldp_neighbor_get_mud_url()</function> function.</para>
2371 </listitem>
2372 </varlistentry>
2373 </variablelist>
2374 </refsect1>
2375
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HP
2376 <refsect1>
2377 <title>[CAN] Section Options</title>
2378 <para>The <literal>[CAN]</literal> section manages the Controller Area Network (CAN bus) and accepts the
2379 following keys.</para>
2380 <variablelist class='network-directives'>
2381 <varlistentry>
2382 <term><varname>BitRate=</varname></term>
2383 <listitem>
2384 <para>The bitrate of CAN device in bits per second. The usual SI prefixes (K, M) with the base of 1000 can
74a27268 2385 be used here. Takes a number in the range 1..4294967295.</para>
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HP
2386 </listitem>
2387 </varlistentry>
2388 <varlistentry>
2389 <term><varname>SamplePoint=</varname></term>
2390 <listitem>
2391 <para>Optional sample point in percent with one decimal (e.g. <literal>75%</literal>,
2392 <literal>87.5%</literal>) or permille (e.g. <literal>875‰</literal>).</para>
2393 </listitem>
2394 </varlistentry>
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RP
2395 <varlistentry>
2396 <term><varname>DataBitRate=</varname></term>
2397 <term><varname>DataSamplePoint=</varname></term>
2398 <listitem>
2399 <para>The bitrate and sample point for the data phase, if CAN-FD is used. These settings are
2400 analogous to the <varname>BitRate=</varname> and <varname>SamplePoint=</varname> keys.</para>
2401 </listitem>
2402 </varlistentry>
2403 <varlistentry>
2404 <term><varname>FDMode=</varname></term>
2405 <listitem>
2406 <para>Takes a boolean. When <literal>yes</literal>, CAN-FD mode is enabled for the interface.
2407 Note, that a bitrate and optional sample point should also be set for the CAN-FD data phase using
2408 the <varname>DataBitRate=</varname> and <varname>DataSamplePoint=</varname> keys.</para>
2409 </listitem>
2410 </varlistentry>
2411 <varlistentry>
2412 <term><varname>FDNonISO=</varname></term>
2413 <listitem>
2414 <para>Takes a boolean. When <literal>yes</literal>, non-ISO CAN-FD mode is enabled for the
2415 interface. When unset, the kernel's default will be used.</para>
2416 </listitem>
2417 </varlistentry>
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HP
2418 <varlistentry>
2419 <term><varname>RestartSec=</varname></term>
2420 <listitem>
2421 <para>Automatic restart delay time. If set to a non-zero value, a restart of the CAN controller will be
2422 triggered automatically in case of a bus-off condition after the specified delay time. Subsecond delays can
2423 be specified using decimals (e.g. <literal>0.1s</literal>) or a <literal>ms</literal> or
2424 <literal>us</literal> postfix. Using <literal>infinity</literal> or <literal>0</literal> will turn the
2425 automatic restart off. By default automatic restart is disabled.</para>
2426 </listitem>
2427 </varlistentry>
52aa38f1
MR
2428 <varlistentry>
2429 <term><varname>Termination=</varname></term>
2430 <listitem>
2431 <para>Takes a boolean. When <literal>yes</literal>, the termination resistor will be selected for
2432 the bias network. When unset, the kernel's default will be used.</para>
2433 </listitem>
2434 </varlistentry>
c423be28
CG
2435 <varlistentry>
2436 <term><varname>TripleSampling=</varname></term>
2437 <listitem>
2438 <para>Takes a boolean. When <literal>yes</literal>, three samples (instead of one) are used to determine
2439 the value of a received bit by majority rule. When unset, the kernel's default will be used.</para>
2440 </listitem>
2441 </varlistentry>
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2442 <varlistentry>
2443 <term><varname>ListenOnly=</varname></term>
2444 <listitem>
2445 <para>Takes a boolean. When <literal>yes</literal>, listen-only mode is enabled. When the
2446 interface is in listen-only mode, the interface neither transmit CAN frames nor send ACK
2447 bit. Listen-only mode is important to debug CAN networks without interfering with the
2448 communication or acknowledge the CAN frame. When unset, the kernel's default will be used.
2449 </para>
2450 </listitem>
2451 </varlistentry>
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HP
2452 </variablelist>
2453 </refsect1>
2454
2ed5f6d5
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2455 <refsect1>
2456 <title>[QDisc] Section Options</title>
2457 <para>The <literal>[QDisc]</literal> section manages the traffic control queueing discipline (qdisc).</para>
2458
2459 <variablelist class='network-directives'>
2460 <varlistentry>
2461 <term><varname>Parent=</varname></term>
2462 <listitem>
2463 <para>Specifies the parent Queueing Discipline (qdisc). Takes one of <literal>clsact</literal>
2464 or <literal>ingress</literal>. This is mandatory.</para>
2465 </listitem>
2466 </varlistentry>
d8b2396d 2467
f344a492 2468 <xi:include href="tc.xml" xpointer="qdisc-handle" />
2ed5f6d5
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2469 </variablelist>
2470 </refsect1>
2471
0f5bd7fe 2472 <refsect1>
18de0969
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2473 <title>[NetworkEmulator] Section Options</title>
2474 <para>The <literal>[NetworkEmulator]</literal> section manages the queueing discipline (qdisc) of
2475 the network emulator. It can be used to configure the kernel packet scheduler and simulate packet
2476 delay and loss for UDP or TCP applications, or limit the bandwidth usage of a particular service to
2477 simulate internet connections.</para>
0f5bd7fe
SS
2478
2479 <variablelist class='network-directives'>
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2480 <xi:include href="tc.xml" xpointer="qdisc-parent" />
2481 <xi:include href="tc.xml" xpointer="qdisc-handle" />
d8b2396d 2482
0f5bd7fe 2483 <varlistentry>
18de0969 2484 <term><varname>DelaySec=</varname></term>
0f5bd7fe
SS
2485 <listitem>
2486 <para>Specifies the fixed amount of delay to be added to all packets going out of the
2487 interface. Defaults to unset.</para>
2488 </listitem>
2489 </varlistentry>
2490
2491 <varlistentry>
18de0969 2492 <term><varname>DelayJitterSec=</varname></term>
0f5bd7fe
SS
2493 <listitem>
2494 <para>Specifies the chosen delay to be added to the packets outgoing to the network
2495 interface. Defaults to unset.</para>
2496 </listitem>
2497 </varlistentry>
2498
2499 <varlistentry>
18de0969 2500 <term><varname>PacketLimit=</varname></term>
0f5bd7fe
SS
2501 <listitem>
2502 <para>Specifies the maximum number of packets the qdisc may hold queued at a time.
2503 An unsigned integer ranges 0 to 4294967294. Defaults to 1000.</para>
2504 </listitem>
2505 </varlistentry>
2506
2507 <varlistentry>
18de0969 2508 <term><varname>LossRate=</varname></term>
0f5bd7fe
SS
2509 <listitem>
2510 <para>Specifies an independent loss probability to be added to the packets outgoing from the
2511 network interface. Takes a percentage value, suffixed with "%". Defaults to unset.</para>
2512 </listitem>
2513 </varlistentry>
2514
b9c5aa3c 2515 <varlistentry>
18de0969 2516 <term><varname>DuplicateRate=</varname></term>
b9c5aa3c
SS
2517 <listitem>
2518 <para>Specifies that the chosen percent of packets is duplicated before queuing them.
2519 Takes a percentage value, suffixed with "%". Defaults to unset.</para>
2520 </listitem>
2521 </varlistentry>
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2522 </variablelist>
2523 </refsect1>
b9c5aa3c 2524
18de0969 2525 <refsect1>
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ZJS
2526 <title>[TokenBucketFilter] Section Options</title>
2527 <para>The <literal>[TokenBucketFilter]</literal> section manages the queueing discipline (qdisc) of
2528 token bucket filter (tbf).</para>
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2529
2530 <variablelist class='network-directives'>
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YW
2531 <xi:include href="tc.xml" xpointer="qdisc-parent" />
2532 <xi:include href="tc.xml" xpointer="qdisc-handle" />
d8b2396d 2533
18de0969
YW
2534 <varlistentry>
2535 <term><varname>LatencySec=</varname></term>
ba5841b5
SS
2536 <listitem>
2537 <para>Specifies the latency parameter, which specifies the maximum amount of time a
60ed2dcf 2538 packet can sit in the Token Bucket Filter (TBF). Defaults to unset.</para>
ba5841b5
SS
2539 </listitem>
2540 </varlistentry>
2541
dcfc23ae 2542 <varlistentry>
18de0969 2543 <term><varname>LimitSize=</varname></term>
dcfc23ae
YW
2544 <listitem>
2545 <para>Takes the number of bytes that can be queued waiting for tokens to become available.
2546 When the size is suffixed with K, M, or G, it is parsed as Kilobytes, Megabytes, or Gigabytes,
2547 respectively, to the base of 1000. Defaults to unset.</para>
2548 </listitem>
2549 </varlistentry>
2550
ba5841b5 2551 <varlistentry>
18de0969 2552 <term><varname>Burst=</varname></term>
ba5841b5
SS
2553 <listitem>
2554 <para>Specifies the size of the bucket. This is the maximum amount of bytes that tokens
2555 can be available for instantaneous transfer. When the size is suffixed with K, M, or G, it is
2556 parsed as Kilobytes, Megabytes, or Gigabytes, respectively, to the base of 1000. Defaults to
2557 unset.</para>
2558 </listitem>
2559 </varlistentry>
2560
2561 <varlistentry>
18de0969 2562 <term><varname>Rate=</varname></term>
ba5841b5
SS
2563 <listitem>
2564 <para>Specifies the device specific bandwidth. When suffixed with K, M, or G, the specified
6b8fe4c3 2565 bandwidth is parsed as Kilobits, Megabits, or Gigabits, respectively, to the base of 1000.
ba5841b5
SS
2566 Defaults to unset.</para>
2567 </listitem>
2568 </varlistentry>
2569
dcfc23ae 2570 <varlistentry>
18de0969 2571 <term><varname>MPUBytes=</varname></term>
dcfc23ae
YW
2572 <listitem>
2573 <para>The Minimum Packet Unit (MPU) determines the minimal token usage (specified in bytes)
2574 for a packet. When suffixed with K, M, or G, the specified size is parsed as Kilobytes,
2575 Megabytes, or Gigabytes, respectively, to the base of 1000. Defaults to zero.</para>
2576 </listitem>
2577 </varlistentry>
2578
2579 <varlistentry>
18de0969 2580 <term><varname>PeakRate=</varname></term>
dcfc23ae
YW
2581 <listitem>
2582 <para>Takes the maximum depletion rate of the bucket. When suffixed with K, M, or G, the
6b8fe4c3 2583 specified size is parsed as Kilobits, Megabits, or Gigabits, respectively, to the base of
dcfc23ae
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2584 1000. Defaults to unset.</para>
2585 </listitem>
2586 </varlistentry>
2587
2588 <varlistentry>
18de0969 2589 <term><varname>MTUBytes=</varname></term>
dcfc23ae
YW
2590 <listitem>
2591 <para>Specifies the size of the peakrate bucket. When suffixed with K, M, or G, the specified
2592 size is parsed as Kilobytes, Megabytes, or Gigabytes, respectively, to the base of 1000.
2593 Defaults to unset.</para>
2594 </listitem>
2595 </varlistentry>
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2596 </variablelist>
2597 </refsect1>
2598
bde4ae88
SS
2599 <refsect1>
2600 <title>[PIE] Section Options</title>
2601 <para>The <literal>[PIE]</literal> section manages the queueing discipline
2602 (qdisc) of Proportional Integral controller-Enhanced (PIE).</para>
2603
2604 <variablelist class='network-directives'>
f344a492
YW
2605 <xi:include href="tc.xml" xpointer="qdisc-parent" />
2606 <xi:include href="tc.xml" xpointer="qdisc-handle" />
bde4ae88
SS
2607
2608 <varlistentry>
2609 <term><varname>PacketLimit=</varname></term>
2610 <listitem>
2611 <para>Specifies the hard limit on the queue size in number of packets. When this limit is reached, incoming packets are
2612 dropped. An unsigned integer ranges 1 to 4294967294. Defaults to unset and kernel's default is used.</para>
2613 </listitem>
2614 </varlistentry>
2615 </variablelist>
2616 </refsect1>
2617
982998b0
SS
2618 <refsect1>
2619 <title>[StochasticFairBlue] Section Options</title>
2620 <para>The <literal>[StochasticFairBlue]</literal> section manages the queueing discipline
2621 (qdisc) of stochastic fair blue (sfb).</para>
2622
2623 <variablelist class='network-directives'>
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YW
2624 <xi:include href="tc.xml" xpointer="qdisc-parent" />
2625 <xi:include href="tc.xml" xpointer="qdisc-handle" />
982998b0
SS
2626
2627 <varlistentry>
2628 <term><varname>PacketLimit=</varname></term>
2629 <listitem>
2630 <para>Specifies the hard limit on the queue size in number of packets. When this limit is reached, incoming packets are
2631 dropped. An unsigned integer ranges 0 to 4294967294. Defaults to unset and kernel's default is used.</para>
2632 </listitem>
2633 </varlistentry>
2634 </variablelist>
2635 </refsect1>
2636
18de0969
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2637 <refsect1>
2638 <title>[StochasticFairnessQueueing] Section Options</title>
2639 <para>The <literal>[StochasticFairnessQueueing]</literal> section manages the queueing discipline
2640 (qdisc) of stochastic fairness queueing (sfq).</para>
2641
2642 <variablelist class='network-directives'>
f344a492
YW
2643 <xi:include href="tc.xml" xpointer="qdisc-parent" />
2644 <xi:include href="tc.xml" xpointer="qdisc-handle" />
d8b2396d 2645
9942b710 2646 <varlistentry>
18de0969 2647 <term><varname>PerturbPeriodSec=</varname></term>
9942b710
SS
2648 <listitem>
2649 <para>Specifies the interval in seconds for queue algorithm perturbation. Defaults to unset.</para>
2650 </listitem>
2651 </varlistentry>
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2652 </variablelist>
2653 </refsect1>
2654
c853f594
SS
2655 <refsect1>
2656 <title>[BFIFO] Section Options</title>
2657 <para>The <literal>[BFIFO]</literal> section manages the queueing discipline (qdisc) of
2658 Byte limited Packet First In First Out (bfifo).</para>
2659
2660 <variablelist class='network-directives'>
f344a492
YW
2661 <xi:include href="tc.xml" xpointer="qdisc-parent" />
2662 <xi:include href="tc.xml" xpointer="qdisc-handle" />
c853f594
SS
2663
2664 <varlistentry>
2665 <term><varname>LimitSize=</varname></term>
2666 <listitem>
2667 <para>Specifies the hard limit on the FIFO size in bytes. The size limit (a buffer size) to prevent it
2668 from overflowing in case it is unable to dequeue packets as quickly as it receives them. When this limit
2669 is reached, incoming packets are dropped. When suffixed with K, M, or G, the specified size is parsed as
2670 Kilobytes, Megabytes, or Gigabytes, respectively, to the base of 1024. Defaults to unset and kernel's default is used.</para>
2671 </listitem>
2672 </varlistentry>
2673 </variablelist>
2674 </refsect1>
2675
a7476065
SS
2676 <refsect1>
2677 <title>[PFIFO] Section Options</title>
2678 <para>The <literal>[PFIFO]</literal> section manages the queueing discipline (qdisc) of
2679 Packet First In First Out (pfifo).</para>
2680
2681 <variablelist class='network-directives'>
f344a492
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2682 <xi:include href="tc.xml" xpointer="qdisc-parent" />
2683 <xi:include href="tc.xml" xpointer="qdisc-handle" />
a7476065
SS
2684
2685 <varlistentry>
2686 <term><varname>PacketLimit=</varname></term>
2687 <listitem>
2688 <para>Specifies the hard limit on the FIFO size in number of packets. The size limit (a buffer size) to prevent it
2689 from overflowing in case it is unable to dequeue packets as quickly as it receives them. When this limit is reached,
2690 incoming packets are dropped. An unsigned integer ranges 0 to 4294967294. Defaults to unset and kernel's default is used.</para>
2691 </listitem>
2692 </varlistentry>
ad8352f4
SS
2693 </variablelist>
2694 </refsect1>
2695
053a2ddb
SS
2696 <refsect1>
2697 <title>[PFIFOHeadDrop] Section Options</title>
2698 <para>The <literal>[PFIFOHeadDrop]</literal> section manages the queueing discipline (qdisc) of
2699 Packet First In First Out Head Drop (pfifo_head_drop).</para>
2700
2701 <variablelist class='network-directives'>
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2702 <xi:include href="tc.xml" xpointer="qdisc-parent" />
2703 <xi:include href="tc.xml" xpointer="qdisc-handle" />
053a2ddb
SS
2704
2705 <varlistentry>
2706 <term><varname>PacketLimit=</varname></term>
2707 <listitem>
2708 <para>As in <literal>[PFIFO]</literal> section.</para></listitem>
2709 </varlistentry>
2710 </variablelist>
2711 </refsect1>
2712
1a95964b
SS
2713 <refsect1>
2714 <title>[PFIFOFast] Section Options</title>
2715 <para>The <literal>[PFIFOFast]</literal> section manages the queueing discipline (qdisc) of
2716 Packet First In First Out Fast (pfifo_fast).</para>
2717
2718 <variablelist class='network-directives'>
f344a492
YW
2719 <xi:include href="tc.xml" xpointer="qdisc-parent" />
2720 <xi:include href="tc.xml" xpointer="qdisc-handle" />
1a95964b
SS
2721 </variablelist>
2722 </refsect1>
2723
ad8352f4
SS
2724 <refsect1>
2725 <title>[CAKE] Section Options</title>
2726 <para>The <literal>[CAKE]</literal> section manages the queueing discipline (qdisc) of
2727 Common Applications Kept Enhanced (CAKE).</para>
2728
2729 <variablelist class='network-directives'>
f344a492
YW
2730 <xi:include href="tc.xml" xpointer="qdisc-parent" />
2731 <xi:include href="tc.xml" xpointer="qdisc-handle" />
a7476065 2732
ad8352f4 2733 <varlistentry>
ad8352f4
SS
2734 <term><varname>Overhead=</varname></term>
2735 <listitem>
2736 <para>Specifies that bytes to be addeded to the size of each packet. Bytes may be negative.
2737 Takes an integer ranges -64 to 256. Defaults to unset and kernel's default is used.</para>
2738 </listitem>
f344a492 2739 </varlistentry>
ad8352f4
SS
2740
2741 <varlistentry>
2742 <term><varname>Bandwidth=</varname></term>
2743 <listitem>
2744 <para>Specifies the shaper bandwidth. When suffixed with K, M, or G, the specified size is
2745 parsed as Kilobits, Megabits, or Gigabits, respectively, to the base of 1000. Defaults to
2746 unset and kernel's default is used.</para>
2747 </listitem>
2748 </varlistentry>
a7476065
SS
2749 </variablelist>
2750 </refsect1>
2751
18de0969
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2752 <refsect1>
2753 <title>[ControlledDelay] Section Options</title>
2754 <para>The <literal>[ControlledDelay]</literal> section manages the queueing discipline (qdisc) of
2755 controlled delay (CoDel).</para>
9942b710 2756
18de0969 2757 <variablelist class='network-directives'>
f344a492
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2758 <xi:include href="tc.xml" xpointer="qdisc-parent" />
2759 <xi:include href="tc.xml" xpointer="qdisc-handle" />
d8b2396d 2760
18de0969
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2761 <varlistentry>
2762 <term><varname>PacketLimit=</varname></term>
a9a5d632 2763 <listitem>
2cd65106 2764 <para>Specifies the hard limit on the queue size in number of packets. When this limit is reached, incoming packets are
a9a5d632
SS
2765 dropped. An unsigned integer ranges 0 to 4294967294. Defaults to unset and kernel's default is used.</para>
2766 </listitem>
2767 </varlistentry>
2768
b078e528 2769 <varlistentry>
18de0969 2770 <term><varname>TargetSec=</varname></term>
b078e528
YW
2771 <listitem>
2772 <para>Takes a timespan. Specifies the acceptable minimum standing/persistent queue delay.
2773 Defaults to unset and kernel's default is used.</para>
2774 </listitem>
2775 </varlistentry>
2776
2777 <varlistentry>
18de0969 2778 <term><varname>IntervalSec=</varname></term>
b078e528
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2779 <listitem>
2780 <para>Takes a timespan. This is used to ensure that the measured minimum delay does not
2781 become too stale. Defaults to unset and kernel's default is used.</para>
2782 </listitem>
2783 </varlistentry>
2784
2785 <varlistentry>
18de0969 2786 <term><varname>ECN=</varname></term>
b078e528
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2787 <listitem>
2788 <para>Takes a boolean. This can be used to mark packets instead of dropping them. Defaults to
2789 unset and kernel's default is used.</para>
2790 </listitem>
2791 </varlistentry>
2792
2793 <varlistentry>
18de0969 2794 <term><varname>CEThresholdSec=</varname></term>
b078e528
YW
2795 <listitem>
2796 <para>Takes a timespan. This sets a threshold above which all packets are marked with ECN
2797 Congestion Experienced (CE). Defaults to unset and kernel's default is used.</para>
2798 </listitem>
2799 </varlistentry>
18de0969
YW
2800 </variablelist>
2801 </refsect1>
b078e528 2802
f5fc0441
SS
2803 <refsect1>
2804 <title>[DeficitRoundRobinScheduler] Section Options</title>
2805 <para>The <literal>[DeficitRoundRobinScheduler]</literal> section manages the queueing discipline (qdisc) of
2806 Deficit Round Robin Scheduler (DRR).</para>
2807
2808 <variablelist class='network-directives'>
f344a492
YW
2809 <xi:include href="tc.xml" xpointer="qdisc-parent" />
2810 <xi:include href="tc.xml" xpointer="qdisc-handle" />
f5fc0441
SS
2811 </variablelist>
2812 </refsect1>
2813
ad365c5d
YW
2814 <refsect1>
2815 <title>[DeficitRoundRobinSchedulerClass] Section Options</title>
2816 <para>The <literal>[DeficitRoundRobinSchedulerClass]</literal> section manages the traffic control class of
2817 Deficit Round Robin Scheduler (DRR).</para>
2818
2819 <variablelist class='network-directives'>
f344a492
YW
2820 <xi:include href="tc.xml" xpointer="tclass-parent" />
2821 <xi:include href="tc.xml" xpointer="tclass-classid" />
ad365c5d
YW
2822
2823 <varlistentry>
2824 <term><varname>Quantum=</varname></term>
2825 <listitem>
2826 <para>Specifies the amount of bytes a flow is allowed to dequeue before the
2827 scheduler moves to the next class. An unsigned integer ranges 1 to 4294967294.
2828 Defaults to the MTU of the interface.</para>
2829 </listitem>
2830 </varlistentry>
2831
2832 </variablelist>
2833 </refsect1>
2834
609e8340
SS
2835 <refsect1>
2836 <title>[GenericRandomEarlyDetection] Section Options</title>
2837 <para>The <literal>[GenericRandomEarlyDetection]</literal> section manages the queueing discipline
2838 (qdisc) of Generic Random Early Detection (GRED).</para>
2839
2840 <variablelist class='network-directives'>
f344a492
YW
2841 <xi:include href="tc.xml" xpointer="qdisc-parent" />
2842 <xi:include href="tc.xml" xpointer="qdisc-handle" />
609e8340
SS
2843
2844 <varlistentry>
2845 <term><varname>VirtualQueues=</varname></term>
2846 <listitem>
2847 <para>Specifies the number of virtual queues. Takes a integer in the range 1-16. Defaults to unset and kernel's default is used.</para>
2848 </listitem>
2849 </varlistentry>
2850
2851 <varlistentry>
2852 <term><varname>DefaultVirtualQueue=</varname></term>
2853 <listitem>
2854 <para>Specifies the number of default virtual queue. This must be less than <varname>VirtualQueue=</varname>.
2855 Defaults to unset and kernel's default is used.</para>
2856 </listitem>
2857 </varlistentry>
2858
2859 <varlistentry>
2860 <term><varname>GenericRIO=</varname></term>
2861 <listitem>
2862 <para>Takes a boolean. It turns on the RIO-like buffering scheme. Defaults to
2863 unset and kernel's default is used.</para>
2864 </listitem>
2865 </varlistentry>
2866 </variablelist>
2867 </refsect1>
2868
18de0969
YW
2869 <refsect1>
2870 <title>[FairQueueingControlledDelay] Section Options</title>
2871 <para>The <literal>[FairQueueingControlledDelay]</literal> section manages the queueing discipline
2872 (qdisc) of fair queuing controlled delay (FQ-CoDel).</para>
2873
2874 <variablelist class='network-directives'>
f344a492
YW
2875 <xi:include href="tc.xml" xpointer="qdisc-parent" />
2876 <xi:include href="tc.xml" xpointer="qdisc-handle" />
d8b2396d 2877
18de0969
YW
2878 <varlistentry>
2879 <term><varname>PacketLimit=</varname></term>
4e5ef149
SS
2880 <listitem>
2881 <para>Specifies the hard limit on the real queue size. When this limit is reached, incoming packets are
2882 dropped. Defaults to unset and kernel's default is used.</para>
2883 </listitem>
2884 </varlistentry>
2885
ac810b75 2886 <varlistentry>
18de0969 2887 <term><varname>MemoryLimit=</varname></term>
ac810b75
YW
2888 <listitem>
2889 <para>Specifies the limit on the total number of bytes that can be queued in this FQ-CoDel instance.
2890 When suffixed with K, M, or G, the specified size is parsed as Kilobytes, Megabytes, or Gigabytes,
2891 respectively, to the base of 1024. Defaults to unset and kernel's default is used.</para>
2892 </listitem>
2893 </varlistentry>
2894
2895 <varlistentry>
18de0969 2896 <term><varname>Flows=</varname></term>
ac810b75
YW
2897 <listitem>
2898 <para>Specifies the number of flows into which the incoming packets are classified.
2899 Defaults to unset and kernel's default is used.</para>
2900 </listitem>
2901 </varlistentry>
2902
2903 <varlistentry>
18de0969 2904 <term><varname>TargetSec=</varname></term>
ac810b75
YW
2905 <listitem>
2906 <para>Takes a timespan. Specifies the acceptable minimum standing/persistent queue delay.
2907 Defaults to unset and kernel's default is used.</para>
2908 </listitem>
2909 </varlistentry>
2910
2911 <varlistentry>
18de0969 2912 <term><varname>IntervalSec=</varname></term>
ac810b75
YW
2913 <listitem>
2914 <para>Takes a timespan. This is used to ensure that the measured minimum delay does not
2915 become too stale. Defaults to unset and kernel's default is used.</para>
2916 </listitem>
2917 </varlistentry>
2918
2919 <varlistentry>
18de0969 2920 <term><varname>Quantum=</varname></term>
ac810b75
YW
2921 <listitem>
2922 <para>Specifies the number of bytes used as 'deficit' in the fair queuing algorithmtimespan.
2923 When suffixed with K, M, or G, the specified size is parsed as Kilobytes, Megabytes, or Gigabytes,
2924 respectively, to the base of 1024. Defaults to unset and kernel's default is used.</para>
2925 </listitem>
2926 </varlistentry>
2927
2928 <varlistentry>
18de0969 2929 <term><varname>ECN=</varname></term>
ac810b75
YW
2930 <listitem>
2931 <para>Takes a boolean. This can be used to mark packets instead of dropping them. Defaults to
2932 unset and kernel's default is used.</para>
2933 </listitem>
2934 </varlistentry>
2935
2936 <varlistentry>
18de0969 2937 <term><varname>CEThresholdSec=</varname></term>
ac810b75
YW
2938 <listitem>
2939 <para>Takes a timespan. This sets a threshold above which all packets are marked with ECN
2940 Congestion Experienced (CE). Defaults to unset and kernel's default is used.</para>
2941 </listitem>
2942 </varlistentry>
18de0969
YW
2943 </variablelist>
2944 </refsect1>
2945
2946 <refsect1>
ca58d00c
ZJS
2947 <title>[FairQueueing] Section Options</title>
2948 <para>The <literal>[FairQueueing]</literal> section manages the queueing discipline
18de0969
YW
2949 (qdisc) of fair queue traffic policing (FQ).</para>
2950
2951 <variablelist class='network-directives'>
f344a492
YW
2952 <xi:include href="tc.xml" xpointer="qdisc-parent" />
2953 <xi:include href="tc.xml" xpointer="qdisc-handle" />
d8b2396d 2954
7234b915 2955 <varlistentry>
18de0969 2956 <term><varname>PacketLimit=</varname></term>
7234b915
SS
2957 <listitem>
2958 <para>Specifies the hard limit on the real queue size. When this limit is reached, incoming packets are
2959 dropped. Defaults to unset and kernel's default is used.</para>
2960 </listitem>
2961 </varlistentry>
2962
e83562e5 2963 <varlistentry>
18de0969 2964 <term><varname>FlowLimit=</varname></term>
e83562e5
YW
2965 <listitem>
2966 <para>Specifies the hard limit on the maximum number of packets queued per flow. Defaults to
2967 unset and kernel's default is used.</para>
2968 </listitem>
2969 </varlistentry>
2970
2971 <varlistentry>
18de0969 2972 <term><varname>Quantum=</varname></term>
e83562e5
YW
2973 <listitem>
2974 <para>Specifies the credit per dequeue RR round, i.e. the amount of bytes a flow is allowed
2975 to dequeue at once. When suffixed with K, M, or G, the specified size is parsed as Kilobytes,
2976 Megabytes, or Gigabytes, respectively, to the base of 1024. Defaults to unset and kernel's
2977 default is used.</para>
2978 </listitem>
2979 </varlistentry>
2980
2981 <varlistentry>
18de0969 2982 <term><varname>InitialQuantum=</varname></term>
e83562e5
YW
2983 <listitem>
2984 <para>Specifies the initial sending rate credit, i.e. the amount of bytes a new flow is
2985 allowed to dequeue initially. When suffixed with K, M, or G, the specified size is parsed as
2986 Kilobytes, Megabytes, or Gigabytes, respectively, to the base of 1024. Defaults to unset and
2987 kernel's default is used.</para>
2988 </listitem>
2989 </varlistentry>
2990
2991 <varlistentry>
18de0969 2992 <term><varname>MaximumRate=</varname></term>
e83562e5
YW
2993 <listitem>
2994 <para>Specifies the maximum sending rate of a flow. When suffixed with K, M, or G, the
6b8fe4c3 2995 specified size is parsed as Kilobits, Megabits, or Gigabits, respectively, to the base of
e83562e5
YW
2996 1000. Defaults to unset and kernel's default is used.</para>
2997 </listitem>
2998 </varlistentry>
2999
3000 <varlistentry>
18de0969 3001 <term><varname>Buckets=</varname></term>
e83562e5
YW
3002 <listitem>
3003 <para>Specifies the size of the hash table used for flow lookups. Defaults to unset and
3004 kernel's default is used.</para>
3005 </listitem>
3006 </varlistentry>
3007
3008 <varlistentry>
18de0969 3009 <term><varname>OrphanMask=</varname></term>
e83562e5
YW
3010 <listitem>
3011 <para>Takes an unsigned integer. For packets not owned by a socket, fq is able to mask a part
3012 of hash and reduce number of buckets associated with the traffic. Defaults to unset and
3013 kernel's default is used.</para>
3014 </listitem>
3015 </varlistentry>
3016
3017 <varlistentry>
18de0969 3018 <term><varname>Pacing=</varname></term>
e83562e5
YW
3019 <listitem>
3020 <para>Takes a boolean, and enables or disables flow pacing. Defaults to unset and kernel's
3021 default is used.</para>
3022 </listitem>
3023 </varlistentry>
3024
3025 <varlistentry>
18de0969 3026 <term><varname>CEThresholdSec=</varname></term>
e83562e5
YW
3027 <listitem>
3028 <para>Takes a timespan. This sets a threshold above which all packets are marked with ECN
3029 Congestion Experienced (CE). Defaults to unset and kernel's default is used.</para>
3030 </listitem>
3031 </varlistentry>
0f5bd7fe
SS
3032 </variablelist>
3033 </refsect1>
3034
9b749c11
YW
3035 <refsect1>
3036 <title>[TrivialLinkEqualizer] Section Options</title>
3037 <para>The <literal>[TrivialLinkEqualizer]</literal> section manages the queueing discipline (qdisc) of
3038 trivial link equalizer (teql).</para>
3039
3040 <variablelist class='network-directives'>
f344a492
YW
3041 <xi:include href="tc.xml" xpointer="qdisc-parent" />
3042 <xi:include href="tc.xml" xpointer="qdisc-handle" />
d8b2396d 3043
9b749c11
YW
3044 <varlistentry>
3045 <term><varname>Id=</varname></term>
3046 <listitem>
3047 <para>Specifies the interface ID <literal>N</literal> of teql. Defaults to <literal>0</literal>.
3048 Note that when teql is used, currently, the module <constant>sch_teql</constant> with
3049 <constant>max_equalizers=N+1</constant> option must be loaded before
3050 <command>systemd-networkd</command> is started.</para>
3051 </listitem>
3052 </varlistentry>
3053 </variablelist>
3054 </refsect1>
3055
b934ac3d
YW
3056 <refsect1>
3057 <title>[HierarchyTokenBucket] Section Options</title>
3058 <para>The <literal>[HierarchyTokenBucket]</literal> section manages the queueing discipline (qdisc) of
3059 hierarchy token bucket (htb).</para>
3060
3061 <variablelist class='network-directives'>
f344a492
YW
3062 <xi:include href="tc.xml" xpointer="qdisc-parent" />
3063 <xi:include href="tc.xml" xpointer="qdisc-handle" />
b934ac3d
YW
3064
3065 <varlistentry>
3066 <term><varname>DefaultClass=</varname></term>
3067 <listitem>
3068 <para>Takes the minor id in hexadecimal of the default class. Unclassified traffic gets sent
3069 to the class. Defaults to unset.</para>
3070 </listitem>
3071 </varlistentry>
3072 </variablelist>
3073 </refsect1>
3074
19f86a63
YW
3075 <refsect1>
3076 <title>[HierarchyTokenBucketClass] Section Options</title>
3077 <para>The <literal>[HierarchyTokenBucketClass]</literal> section manages the traffic control class of
3078 hierarchy token bucket (htb).</para>
3079
3080 <variablelist class='network-directives'>
f344a492
YW
3081 <xi:include href="tc.xml" xpointer="tclass-parent" />
3082 <xi:include href="tc.xml" xpointer="tclass-classid" />
19f86a63
YW
3083
3084 <varlistentry>
3085 <term><varname>Priority=</varname></term>
3086 <listitem>
3087 <para>Specifies the priority of the class. In the round-robin process, classes with the lowest
3088 priority field are tried for packets first. This setting is mandatory.</para>
3089 </listitem>
3090 </varlistentry>
3091
3092 <varlistentry>
3093 <term><varname>Rate=</varname></term>
3094 <listitem>
3095 <para>Specifies the maximum rate this class and all its children are guaranteed. When suffixed
3096 with K, M, or G, the specified size is parsed as Kilobits, Megabits, or Gigabits, respectively,
3097 to the base of 1000. This setting is mandatory.</para>
3098 </listitem>
3099 </varlistentry>
3100
3101 <varlistentry>
3102 <term><varname>CeilRate=</varname></term>
3103 <listitem>
3104 <para>Specifies the maximum rate at which a class can send, if its parent has bandwidth to spare.
3105 When suffixed with K, M, or G, the specified size is parsed as Kilobits, Megabits, or Gigabits,
3106 respectively, to the base of 1000. When unset, the value specified with <varname>Rate=</varname>
3107 is used.</para>
3108 </listitem>
3109 </varlistentry>
7f224020
SS
3110 </variablelist>
3111 </refsect1>
3112
3113 <refsect1>
3114 <title>[HeavyHitterFilter] Section Options</title>
3115 <para>The <literal>[HeavyHitterFilter]</literal> section manages the queueing discipline
3116 (qdisc) of Heavy Hitter Filter (hhf).</para>
3117
3118 <variablelist class='network-directives'>
f344a492
YW
3119 <xi:include href="tc.xml" xpointer="qdisc-parent" />
3120 <xi:include href="tc.xml" xpointer="qdisc-handle" />
19f86a63 3121
7f224020
SS
3122 <varlistentry>
3123 <term><varname>PacketLimit=</varname></term>
3124 <listitem>
3125 <para>Specifies the hard limit on the queue size in number of packets. When this limit is reached, incoming packets are
3126 dropped. An unsigned integer ranges 0 to 4294967294. Defaults to unset and kernel's default is used.</para>
3127 </listitem>
3128 </varlistentry>
19f86a63
YW
3129 </variablelist>
3130 </refsect1>
3131
13b498f9
TJ
3132 <refsect1>
3133 <title>[BridgeVLAN] Section Options</title>
3134 <para>The <literal>[BridgeVLAN]</literal> section manages the VLAN ID configuration of a bridge port and accepts
3135 the following keys. Specify several <literal>[BridgeVLAN]</literal> sections to configure several VLAN entries.
3136 The <varname>VLANFiltering=</varname> option has to be enabled, see <literal>[Bridge]</literal> section in
3137 <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
3138
3139 <variablelist class='network-directives'>
3140 <varlistentry>
3141 <term><varname>VLAN=</varname></term>
3142 <listitem>
3143 <para>The VLAN ID allowed on the port. This can be either a single ID or a range M-N. VLAN IDs are valid
3144 from 1 to 4094.</para>
3145 </listitem>
3146 </varlistentry>
3147 <varlistentry>
3148 <term><varname>EgressUntagged=</varname></term>
3149 <listitem>
3150 <para>The VLAN ID specified here will be used to untag frames on egress. Configuring
3151 <varname>EgressUntagged=</varname> implicates the use of <varname>VLAN=</varname> above and will enable the
3152 VLAN ID for ingress as well. This can be either a single ID or a range M-N.</para>
3153 </listitem>
3154 </varlistentry>
3155 <varlistentry>
3156 <term><varname>PVID=</varname></term>
3157 <listitem>
3158 <para>The Port VLAN ID specified here is assigned to all untagged frames at ingress.
3159 <varname>PVID=</varname> can be used only once. Configuring <varname>PVID=</varname> implicates the use of
3160 <varname>VLAN=</varname> above and will enable the VLAN ID for ingress as well.</para>
3161 </listitem>
3162 </varlistentry>
3163 </variablelist>
3164 </refsect1>
798d3a52
ZJS
3165
3166 <refsect1>
9e35b3de 3167 <title>Examples</title>
798d3a52 3168 <example>
9e35b3de 3169 <title>Static network configuration</title>
798d3a52 3170
9e35b3de
ZJS
3171 <programlisting># /etc/systemd/network/50-static.network
3172[Match]
eac684ef
TG
3173Name=enp2s0
3174
3175[Network]
3176Address=192.168.0.15/24
3177Gateway=192.168.0.1</programlisting>
9e35b3de
ZJS
3178
3179 <para>This brings interface <literal>enp2s0</literal> up with a static address. The
3180 specified gateway will be used for a default route.</para>
798d3a52 3181 </example>
eac684ef 3182
798d3a52 3183 <example>
9e35b3de 3184 <title>DHCP on ethernet links</title>
eac684ef 3185
9e35b3de
ZJS
3186 <programlisting># /etc/systemd/network/80-dhcp.network
3187[Match]
eac684ef
TG
3188Name=en*
3189
3190[Network]
9c8ca3f7 3191DHCP=yes</programlisting>
9e35b3de
ZJS
3192
3193 <para>This will enable DHCPv4 and DHCPv6 on all interfaces with names starting with
3194 <literal>en</literal> (i.e. ethernet interfaces).</para>
798d3a52 3195 </example>
eac684ef 3196
4c94a4c2 3197 <example>
3198 <title>IPv6 Prefix Delegation</title>
3199
3200 <programlisting># /etc/systemd/network/55-ipv6-pd-upstream.network
3201[Match]
3202Name=enp1s0
3203
3204[Network]
3205DHCP=ipv6</programlisting>
3206
3207 <programlisting># /etc/systemd/network/56-ipv6-pd-downstream.network
3208[Match]
3209Name=enp2s0
3210
3211[Network]
3212IPv6PrefixDelegation=dhcpv6</programlisting>
3213
3214 <para>This will enable IPv6 PD on the interface enp1s0 as an upstream interface where the
3215 DHCPv6 client is running and enp2s0 as a downstream interface where the prefix is delegated to.</para>
3216 </example>
3217
798d3a52 3218 <example>
9e35b3de 3219 <title>A bridge with two enslaved links</title>
f47c5c47 3220
9e35b3de
ZJS
3221 <programlisting># /etc/systemd/network/25-bridge-static.network
3222[Match]
f47c5c47 3223Name=bridge0
3224
3225[Network]
3226Address=192.168.0.15/24
3227Gateway=192.168.0.1
3228DNS=192.168.0.1</programlisting>
f47c5c47 3229
9e35b3de
ZJS
3230 <programlisting># /etc/systemd/network/25-bridge-slave-interface-1.network
3231[Match]
f47c5c47 3232Name=enp2s0
3233
3234[Network]
3235Bridge=bridge0</programlisting>
9e35b3de
ZJS
3236
3237 <programlisting># /etc/systemd/network/25-bridge-slave-interface-2.network
3238[Match]
3239Name=wlp3s0
3240
3241[Network]
3242Bridge=bridge0</programlisting>
3243
3244 <para>This creates a bridge and attaches devices <literal>enp2s0</literal> and
3245 <literal>wlp3s0</literal> to it. The bridge will have the specified static address
3246 and network assigned, and a default route via the specified gateway will be
3247 added. The specified DNS server will be added to the global list of DNS resolvers.
3248 </para>
13b498f9 3249 </example>
9e35b3de 3250
13b498f9 3251 <example>
9e35b3de 3252 <title></title>
13b498f9 3253
9e35b3de
ZJS
3254 <programlisting>
3255# /etc/systemd/network/20-bridge-slave-interface-vlan.network
3256[Match]
13b498f9
TJ
3257Name=enp2s0
3258
3259[Network]
3260Bridge=bridge0
3261
3262[BridgeVLAN]
3263VLAN=1-32
3264PVID=42
3265EgressUntagged=42
3266
3267[BridgeVLAN]
3268VLAN=100-200
3269
3270[BridgeVLAN]
3271EgressUntagged=300-400</programlisting>
0a8a0fad 3272
9e35b3de
ZJS
3273 <para>This overrides the configuration specified in the previous example for the
3274 interface <literal>enp2s0</literal>, and enables VLAN on that bridge port. VLAN IDs
3275 1-32, 42, 100-400 will be allowed. Packets tagged with VLAN IDs 42, 300-400 will be
3276 untagged when they leave on this interface. Untagged packets which arrive on this
3277 interface will be assigned VLAN ID 42.</para>
798d3a52 3278 </example>
0a8a0fad 3279
798d3a52 3280 <example>
9e35b3de 3281 <title>Various tunnels</title>
0a8a0fad 3282
9e35b3de
ZJS
3283 <programlisting>/etc/systemd/network/25-tunnels.network
3284[Match]
3285Name=ens1
0a8a0fad
TG
3286
3287[Network]
9e35b3de
ZJS
3288Tunnel=ipip-tun
3289Tunnel=sit-tun
3290Tunnel=gre-tun
3291Tunnel=vti-tun
3292 </programlisting>
3293
3294 <programlisting>/etc/systemd/network/25-tunnel-ipip.netdev
3295[NetDev]
3296Name=ipip-tun
3297Kind=ipip
3298 </programlisting>
3299
3300 <programlisting>/etc/systemd/network/25-tunnel-sit.netdev
3301[NetDev]
3302Name=sit-tun
3303Kind=sit
3304 </programlisting>
3305
3306 <programlisting>/etc/systemd/network/25-tunnel-gre.netdev
3307[NetDev]
3308Name=gre-tun
3309Kind=gre
3310 </programlisting>
3311
3312 <programlisting>/etc/systemd/network/25-tunnel-vti.netdev
3313[NetDev]
3314Name=vti-tun
3315Kind=vti
3316 </programlisting>
3317
3318 <para>This will bring interface <literal>ens1</literal> up and create an IPIP tunnel,
3319 a SIT tunnel, a GRE tunnel, and a VTI tunnel using it.</para>
798d3a52 3320 </example>
0a8a0fad 3321
798d3a52 3322 <example>
9e35b3de 3323 <title>A bond device</title>
0a8a0fad 3324
9e35b3de
ZJS
3325 <programlisting># /etc/systemd/network/30-bond1.network
3326[Match]
3327Name=bond1
0a8a0fad
TG
3328
3329[Network]
9e35b3de
ZJS
3330DHCP=ipv6
3331</programlisting>
0a8a0fad 3332
9e35b3de
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3333 <programlisting># /etc/systemd/network/30-bond1.netdev
3334[NetDev]
3335Name=bond1
3336Kind=bond
3337</programlisting>
0a8a0fad 3338
301a21a8 3339 <programlisting># /etc/systemd/network/30-bond1-dev1.network
9e35b3de
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3340[Match]
3341MACAddress=52:54:00:e9:64:41
0a8a0fad
TG
3342
3343[Network]
9e35b3de
ZJS
3344Bond=bond1
3345</programlisting>
d94facdc 3346
301a21a8 3347 <programlisting># /etc/systemd/network/30-bond1-dev2.network
9e35b3de
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3348[Match]
3349MACAddress=52:54:00:e9:64:42
d94facdc
MH
3350
3351[Network]
9e35b3de 3352Bond=bond1
6cb955c6 3353</programlisting>
9e35b3de
ZJS
3354
3355 <para>This will create a bond device <literal>bond1</literal> and enslave the two
3356 devices with MAC addresses 52:54:00:e9:64:41 and 52:54:00:e9:64:42 to it. IPv6 DHCP
3357 will be used to acquire an address.</para>
6cb955c6
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3358 </example>
3359
3360 <example>
9e35b3de
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3361 <title>Virtual Routing and Forwarding (VRF)</title>
3362 <para>Add the <literal>bond1</literal> interface to the VRF master interface
3363 <literal>vrf1</literal>. This will redirect routes generated on this interface to be
11d38b90
AR
3364 within the routing table defined during VRF creation. For kernels before 4.8 traffic
3365 won't be redirected towards the VRFs routing table unless specific ip-rules are added.
3366 </para>
9e35b3de
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3367 <programlisting># /etc/systemd/network/25-vrf.network
3368[Match]
6cb955c6
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3369Name=bond1
3370
3371[Network]
9e35b3de 3372VRF=vrf1
d94facdc
MH
3373</programlisting>
3374 </example>
3375
42125eda
SS
3376 <example>
3377 <title>MacVTap</title>
3378 <para>This brings up a network interface <literal>macvtap-test</literal>
3379 and attaches it to <literal>enp0s25</literal>.</para>
83ddf5d3 3380 <programlisting># /usr/lib/systemd/network/25-macvtap.network
42125eda
SS
3381[Match]
3382Name=enp0s25
3383
3384[Network]
3385MACVTAP=macvtap-test
3386</programlisting>
3387 </example>
98d20a17 3388
3389 <example>
3390 <title>A Xfrm interface with physical underlying device.</title>
3391
3392 <programlisting># /etc/systemd/network/27-xfrm.netdev
3393[NetDev]
3394Name=xfrm0
3395
3396[Xfrm]
3397InterfaceId=7</programlisting>
3398
3399 <programlisting># /etc/systemd/network/27-eth0.network
3400[Match]
3401Name=eth0
3402
3403[Network]
3404Xfrm=xfrm0</programlisting>
3405
3406 <para>This creates a <literal>xfrm0</literal> interface and binds it to the <literal>eth0</literal> device.
3407 This allows hardware based ipsec offloading to the <literal>eth0</literal> nic.
3408 If offloading is not needed, xfrm interfaces can be assigned to the <literal>lo</literal> device.
3409 </para>
3410 </example>
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3411 </refsect1>
3412
3413 <refsect1>
3414 <title>See Also</title>
3415 <para>
3416 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
f41b446a 3417 <citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
798d3a52 3418 <citerefentry><refentrytitle>systemd.link</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
aaa297d4
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3419 <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
3420 <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
798d3a52
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3421 </para>
3422 </refsect1>
eac684ef
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3423
3424</refentry>