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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 13:00:47 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 13:00:47 +0000 |
| commit | 2cb7e0aaedad73b076ea18c6900b0e86c5760d79 (patch) | |
| tree | da68ca54bb79f4080079bf0828acda937593a4e1 /man/systemd.network.xml | |
| parent | Initial commit. (diff) | |
| download | systemd-2cb7e0aaedad73b076ea18c6900b0e86c5760d79.tar.xz systemd-2cb7e0aaedad73b076ea18c6900b0e86c5760d79.zip | |
Adding upstream version 247.3.upstream/247.3upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'man/systemd.network.xml')
| -rw-r--r-- | man/systemd.network.xml | 3847 |
1 files changed, 3847 insertions, 0 deletions
diff --git a/man/systemd.network.xml b/man/systemd.network.xml new file mode 100644 index 0000000..6314a82 --- /dev/null +++ b/man/systemd.network.xml @@ -0,0 +1,3847 @@ +<?xml version='1.0'?> +<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" + "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> +<!-- SPDX-License-Identifier: LGPL-2.1-or-later --> + +<refentry id="systemd.network" conditional='ENABLE_NETWORKD' + xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>systemd.network</title> + <productname>systemd</productname> + </refentryinfo> + + <refmeta> + <refentrytitle>systemd.network</refentrytitle> + <manvolnum>5</manvolnum> + </refmeta> + + <refnamediv> + <refname>systemd.network</refname> + <refpurpose>Network configuration</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <para><filename><replaceable>network</replaceable>.network</filename></para> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para>A plain ini-style text file that encodes network configuration for matching network interfaces, + used by + <citerefentry><refentrytitle>systemd-networkd</refentrytitle><manvolnum>8</manvolnum></citerefentry>. + See <citerefentry><refentrytitle>systemd.syntax</refentrytitle><manvolnum>7</manvolnum></citerefentry> + for a general description of the syntax.</para> + + <para>The main network file must have the extension <filename>.network</filename>; other + extensions are ignored. Networks are applied to links whenever the links appear.</para> + + <para>The <filename>.network</filename> files are read from the files located in the system network + directories <filename>/usr/lib/systemd/network</filename> and + <filename>/usr/local/lib/systemd/network</filename>, the volatile runtime network directory + <filename>/run/systemd/network</filename> and the local administration network directory + <filename>/etc/systemd/network</filename>. All configuration files are collectively sorted and processed + in lexical order, regardless of the directories in which they live. However, files with identical + filenames replace each other. Files in <filename>/etc/</filename> have the highest priority, files in + <filename>/run/</filename> take precedence over files with the same name under + <filename>/usr/</filename>. This can be used to override a system-supplied configuration file with a local + file if needed. As a special case, an empty file (file size 0) or symlink with the same name pointing to + <filename>/dev/null</filename> disables the configuration file entirely (it is "masked").</para> + + <para>Along with the network file <filename>foo.network</filename>, a "drop-in" directory + <filename>foo.network.d/</filename> may exist. All files with the suffix + <literal>.conf</literal> from this directory will be parsed after the file itself is + parsed. This is useful to alter or add configuration settings, without having to modify the main + configuration file. Each drop-in file must have appropriate section headers.</para> + + <para>In addition to <filename>/etc/systemd/network</filename>, drop-in <literal>.d</literal> + directories can be placed in <filename>/usr/lib/systemd/network</filename> or + <filename>/run/systemd/network</filename> directories. Drop-in files in + <filename>/etc/</filename> take precedence over those in <filename>/run/</filename> which in turn + take precedence over those in <filename>/usr/lib/</filename>. Drop-in files under any of these + directories take precedence over the main network file wherever located.</para> + + <para>Note that an interface without any static IPv6 addresses configured, and neither DHCPv6 + nor IPv6LL enabled, shall be considered to have no IPv6 support. IPv6 will be automatically + disabled for that interface by writing "1" to + <filename>/proc/sys/net/ipv6/conf/<replaceable>ifname</replaceable>/disable_ipv6</filename>. + </para> + </refsect1> + + <refsect1> + <title>[Match] Section Options</title> + + <para>The network file contains a [Match] section, which determines if a given network file may be + applied to a given device; and a [Network] section specifying how the device should be configured. The + first (in lexical order) of the network files that matches a given device is applied, all later files + are ignored, even if they match as well.</para> + + <para>A network file is said to match a network interface if all matches specified by the [Match] + section are satisfied. When a network file does not contain valid settings in [Match] section, then the + file will match all interfaces and <command>systemd-networkd</command> warns about that. Hint: to avoid + the warning and to make it clear that all interfaces shall be matched, add the following: + <programlisting>Name=*</programlisting> The following keys are accepted:</para> + + <variablelist class='network-directives'> + <xi:include href="systemd.link.xml" xpointer="mac-address" /> + <xi:include href="systemd.link.xml" xpointer="permanent-mac-address" /> + <xi:include href="systemd.link.xml" xpointer="path" /> + <xi:include href="systemd.link.xml" xpointer="driver" /> + <xi:include href="systemd.link.xml" xpointer="type" /> + <xi:include href="systemd.link.xml" xpointer="property" /> + + <varlistentry> + <term><varname>Name=</varname></term> + <listitem> + <para>A whitespace-separated list of shell-style globs matching the device name, as exposed + by the udev property <literal>INTERFACE</literal>, or device's alternative names. If the + list is prefixed with a "!", the test is inverted.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>WLANInterfaceType=</varname></term> + <listitem> + <para>A whitespace-separated list of wireless network type. Supported values are + <literal>ad-hoc</literal>, <literal>station</literal>, <literal>ap</literal>, + <literal>ap-vlan</literal>, <literal>wds</literal>, <literal>monitor</literal>, + <literal>mesh-point</literal>, <literal>p2p-client</literal>, <literal>p2p-go</literal>, + <literal>p2p-device</literal>, <literal>ocb</literal>, and <literal>nan</literal>. If the + list is prefixed with a "!", the test is inverted. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>SSID=</varname></term> + <listitem> + <para>A whitespace-separated list of shell-style globs matching the SSID of the currently + connected wireless LAN. If the list is prefixed with a "!", the test is inverted. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>BSSID=</varname></term> + <listitem> + <para>A whitespace-separated list of hardware address of the currently connected wireless + LAN. Use full colon-, hyphen- or dot-delimited hexadecimal. See the example in + <varname>MACAddress=</varname>. This option may appear more than once, in which case the + lists are merged. If the empty string is assigned to this option, the list is reset.</para> + </listitem> + </varlistentry> + + <xi:include href="systemd.link.xml" xpointer="host" /> + <xi:include href="systemd.link.xml" xpointer="virtualization" /> + <xi:include href="systemd.link.xml" xpointer="kernel-command-line" /> + <xi:include href="systemd.link.xml" xpointer="kernel-version" /> + <xi:include href="systemd.link.xml" xpointer="architecture" /> + </variablelist> + + </refsect1> + + <refsect1> + <title>[Link] Section Options</title> + + <para> The [Link] section accepts the following keys:</para> + + <variablelist class='network-directives'> + <varlistentry> + <term><varname>MACAddress=</varname></term> + <listitem> + <para>The hardware address to set for the device.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>MTUBytes=</varname></term> + <listitem> + <para>The maximum transmission unit in bytes to set for the + device. The usual suffixes K, M, G, are supported and are + understood to the base of 1024.</para> + <para>Note that if IPv6 is enabled on the interface, and the MTU is chosen + below 1280 (the minimum MTU for IPv6) it will automatically be increased to this value.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>ARP=</varname></term> + <listitem> + <para>Takes a boolean. If set to true, the ARP (low-level Address Resolution Protocol) + for this interface is enabled. When unset, the kernel's default will be used.</para> + <para> For example, disabling ARP is useful when creating multiple MACVLAN or VLAN virtual + interfaces atop a single lower-level physical interface, which will then only serve as a + link/"bridge" device aggregating traffic to the same physical link and not participate in + the network otherwise.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Multicast=</varname></term> + <listitem> + <para>Takes a boolean. If set to true, the multicast flag on the device is enabled.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>AllMulticast=</varname></term> + <listitem> + <para>Takes a boolean. If set to true, the driver retrieves all multicast packets from the network. + This happens when multicast routing is enabled.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Unmanaged=</varname></term> + <listitem> + <para>Takes a boolean. When <literal>yes</literal>, no attempts are + made to bring up or configure matching links, equivalent to + when there are no matching network files. Defaults to + <literal>no</literal>.</para> + <para>This is useful for preventing later matching network + files from interfering with certain interfaces that are fully + controlled by other applications.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Group=</varname></term> + <listitem> + <para>Link groups are similar to port ranges found in managed switches. + When network interfaces are added to a numbered group, operations on + all the interfaces from that group can be performed at once. An unsigned + integer in the range 0—4294967294. Defaults to unset.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>RequiredForOnline=</varname></term> + <listitem> + <para>Takes a boolean or a minimum operational state and an optional maximum operational state. + Please see <citerefentry><refentrytitle>networkctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> + for possible operational states. When <literal>yes</literal>, the network is deemed required when + determining whether the system is online when running + <command>systemd-networkd-wait-online</command>. When <literal>no</literal>, the network is ignored + when checking for online state. When a minimum operational state and an optional maximum operational + state are set, <literal>yes</literal> is implied, and this controls the minimum and maximum + operational state required for the network interface to be considered online. + Defaults to <literal>yes</literal>.</para> + + <para>The network will be brought up normally in all cases, but in + the event that there is no address being assigned by DHCP or the + cable is not plugged in, the link will simply remain offline and be + skipped automatically by <command>systemd-networkd-wait-online</command> + if <literal>RequiredForOnline=no</literal>.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[SR-IOV] Section Options</title> + <para>The [SR-IOV] section accepts the following keys. Specify several [SR-IOV] sections to configure + several SR-IOVs. SR-IOV provides the ability to partition a single physical PCI resource into virtual + PCI functions which can then be injected into a VM. In the case of network VFs, SR-IOV improves + north-south network performance (that is, traffic with endpoints outside the host machine) by allowing + traffic to bypass the host machine’s network stack.</para> + + <variablelist class='network-directives'> + <varlistentry> + <term><varname>VirtualFunction=</varname></term> + <listitem> + <para>Specifies a Virtual Function (VF), lightweight PCIe function designed solely to move data + in and out. Takes an unsigned integer in the range 0..2147483646. This option is compulsory.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>VLANId=</varname></term> + <listitem> + <para>Specifies VLAN ID of the virtual function. Takes an unsigned integer in the range 1..4095.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>QualityOfService=</varname></term> + <listitem> + <para>Specifies quality of service of the virtual function. Takes an unsigned integer in the range 1..4294967294.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>VLANProtocol=</varname></term> + <listitem> + <para>Specifies VLAN protocol of the virtual function. Takes <literal>802.1Q</literal> or + <literal>802.1ad</literal>.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>MACSpoofCheck=</varname></term> + <listitem> + <para>Takes a boolean. Controls the MAC spoof checking. When unset, the kernel's default will be used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>QueryReceiveSideScaling=</varname></term> + <listitem> + <para>Takes a boolean. Toggle the ability of querying the receive side scaling (RSS) + configuration of the virtual function (VF). The VF RSS information like RSS hash key may be + considered sensitive on some devices where this information is shared between VF and the + physical function (PF). When unset, the kernel's default will be used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>Trust=</varname></term> + <listitem> + <para>Takes a boolean. Allows to set trust mode of the virtual function (VF). When set, VF + users can set a specific feature which may impact security and/or performance. When unset, + the kernel's default will be used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>LinkState=</varname></term> + <listitem> + <para>Allows to set the link state of the virtual function (VF). Takes a boolean or a + special value <literal>auto</literal>. Setting to <literal>auto</literal> means a + reflection of the physical function (PF) link state, <literal>yes</literal> lets the VF to + communicate with other VFs on this host even if the PF link state is down, + <literal>no</literal> causes the hardware to drop any packets sent by the VF. When unset, + the kernel's default will be used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>MACAddress=</varname></term> + <listitem> + <para>Specifies the MAC address for the virtual function.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[Network] Section Options</title> + + <para>The [Network] section accepts the following keys:</para> + + <variablelist class='network-directives'> + <varlistentry> + <term><varname>Description=</varname></term> + <listitem> + <para>A description of the device. This is only used for + presentation purposes.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>DHCP=</varname></term> + <listitem> + <para>Enables DHCPv4 and/or DHCPv6 client support. Accepts + <literal>yes</literal>, <literal>no</literal>, + <literal>ipv4</literal>, or <literal>ipv6</literal>. Defaults + to <literal>no</literal>.</para> + + <para>Note that DHCPv6 will by default be triggered by Router + Advertisement, if that is enabled, regardless of this parameter. + By enabling DHCPv6 support explicitly, the DHCPv6 client will + be started regardless of the presence of routers on the link, + or what flags the routers pass. See + <literal>IPv6AcceptRA=</literal>.</para> + + <para>Furthermore, note that by default the domain name + specified through DHCP is not used for name resolution. + See option <option>UseDomains=</option> below.</para> + + <para>See the [DHCPv4] or [DHCPv6] sections below for further configuration options for the DHCP + client support.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>DHCPServer=</varname></term> + <listitem> + <para>Takes a boolean. If set to <literal>yes</literal>, DHCPv4 server will be started. Defaults + to <literal>no</literal>. Further settings for the DHCP server may be set in the [DHCPServer] + section described below.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>LinkLocalAddressing=</varname></term> + <listitem> + <para>Enables link-local address autoconfiguration. Accepts <literal>yes</literal>, + <literal>no</literal>, <literal>ipv4</literal>, <literal>ipv6</literal>, + <literal>fallback</literal>, or <literal>ipv4-fallback</literal>. If + <literal>fallback</literal> or <literal>ipv4-fallback</literal> is specified, then an IPv4 + link-local address is configured only when DHCPv4 fails. If <literal>fallback</literal>, + an IPv6 link-local address is always configured, and if <literal>ipv4-fallback</literal>, + the address is not configured. Note that, the fallback mechanism works only when DHCPv4 + client is enabled, that is, it requires <literal>DHCP=yes</literal> or + <literal>DHCP=ipv4</literal>. If <varname>Bridge=</varname> is set, defaults to + <literal>no</literal>, and if not, defaults to <literal>ipv6</literal>. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>IPv6LinkLocalAddressGenerationMode=</varname></term> + <listitem> + <para>Specifies how IPv6 link local address is generated. Takes one of <literal>eui64</literal>, + <literal>none</literal>, <literal>stable-privacy</literal> and <literal>random</literal>. + When unset, the kernel's default will be used. Note that if <varname>LinkLocalAdressing=</varname> + not configured as <literal>ipv6</literal> then <varname>IPv6LinkLocalAddressGenerationMode=</varname> + is ignored.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>IPv4LLRoute=</varname></term> + <listitem> + <para>Takes a boolean. If set to true, sets up the route needed for + non-IPv4LL hosts to communicate with IPv4LL-only hosts. Defaults + to false. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>DefaultRouteOnDevice=</varname></term> + <listitem> + <para>Takes a boolean. If set to true, sets up the default route bound to the interface. + Defaults to false. This is useful when creating routes on point-to-point interfaces. + This is equivalent to e.g. the following. + <programlisting>ip route add default dev veth99</programlisting></para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>IPv6Token=</varname></term> + <listitem> + <para>Specifies an optional address generation mode for the Stateless Address + Autoconfiguration (SLAAC). Supported modes are <literal>prefixstable</literal> and + <literal>static</literal>.</para> + + <para>When the mode is set to <literal>static</literal>, an IPv6 address must be + specified after a colon (<literal>:</literal>), and the lower bits of the supplied + address are combined with the upper bits of a prefix received in a Router Advertisement + (RA) message to form a complete address. Note that if multiple prefixes are received in an + RA message, or in multiple RA messages, addresses will be formed from each of them using + the supplied address. This mode implements SLAAC but uses a static interface identifier + instead of an identifier generated by using the EUI-64 algorithm. Because the interface + identifier is static, if Duplicate Address Detection detects that the computed address is a + duplicate (in use by another node on the link), then this mode will fail to provide an + address for that prefix. If an IPv6 address without mode is specified, then + <literal>static</literal> mode is assumed.</para> + + <para>When the mode is set to <literal>prefixstable</literal> the + <ulink url="https://tools.ietf.org/html/rfc7217">RFC 7217</ulink> algorithm for generating + interface identifiers will be used. This mode can optionally take an IPv6 address separated + with a colon (<literal>:</literal>). If an IPv6 address is specified, then an interface + identifier is generated only when a prefix received in an RA message matches the supplied + address.</para> + + <para>If no address generation mode is specified (which is the default), or a received + prefix does not match any of the addresses provided in <literal>prefixstable</literal> + mode, then the EUI-64 algorithm will be used to form an interface identifier for that + prefix. This mode is also SLAAC, but with a potentially stable interface identifier which + does not directly map to the interface's hardware address.</para> + + <para>Note that the <literal>prefixstable</literal> algorithm uses both the interface + name and MAC address as input to the hash to compute the interface identifier, so if either + of those are changed the resulting interface identifier (and address) will change, even if + the prefix received in the RA message has not changed.</para> + + <para>This setting can be specified multiple times. If an empty string is assigned, then + the all previous assignments are cleared.</para> + + <para>Examples: + <programlisting>IPv6Token=::1a:2b:3c:4d +IPv6Token=static:::1a:2b:3c:4d +IPv6Token=prefixstable +IPv6Token=prefixstable:2002:da8:1::</programlisting></para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>LLMNR=</varname></term> + <listitem> + <para>Takes a boolean or <literal>resolve</literal>. When true, + enables <ulink + url="https://tools.ietf.org/html/rfc4795">Link-Local + Multicast Name Resolution</ulink> on the link. When set to + <literal>resolve</literal>, only resolution is enabled, + but not host registration and announcement. Defaults to + true. This setting is read by + <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>MulticastDNS=</varname></term> + <listitem> + <para>Takes a boolean or <literal>resolve</literal>. When true, + enables <ulink + url="https://tools.ietf.org/html/rfc6762">Multicast + DNS</ulink> support on the link. When set to + <literal>resolve</literal>, only resolution is enabled, + but not host or service registration and + announcement. Defaults to false. This setting is read by + <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>DNSOverTLS=</varname></term> + <listitem> + <para>Takes a boolean or <literal>opportunistic</literal>. + When true, enables + <ulink + url="https://tools.ietf.org/html/rfc7858">DNS-over-TLS</ulink> + support on the link. + When set to <literal>opportunistic</literal>, compatibility with + non-DNS-over-TLS servers is increased, by automatically + turning off DNS-over-TLS servers in this case. + This option defines a per-interface setting for + <citerefentry><refentrytitle>resolved.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>'s + global <varname>DNSOverTLS=</varname> option. Defaults to + false. This setting is read by + <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>DNSSEC=</varname></term> + <listitem> + <para>Takes a boolean or <literal>allow-downgrade</literal>. When true, enables + <ulink url="https://tools.ietf.org/html/rfc4033">DNSSEC</ulink> + DNS validation support on the link. When set to + <literal>allow-downgrade</literal>, compatibility with + non-DNSSEC capable networks is increased, by automatically + turning off DNSSEC in this case. This option defines a + per-interface setting for + <citerefentry><refentrytitle>resolved.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>'s + global <varname>DNSSEC=</varname> option. Defaults to + false. This setting is read by + <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>DNSSECNegativeTrustAnchors=</varname></term> + <listitem><para>A space-separated list of DNSSEC negative + trust anchor domains. If specified and DNSSEC is enabled, + look-ups done via the interface's DNS server will be subject + to the list of negative trust anchors, and not require + authentication for the specified domains, or anything below + it. Use this to disable DNSSEC authentication for specific + private domains, that cannot be proven valid using the + Internet DNS hierarchy. Defaults to the empty list. This + setting is read by + <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>LLDP=</varname></term> + <listitem> + <para>Controls support for Ethernet LLDP packet reception. LLDP is a link-layer protocol commonly + implemented on professional routers and bridges which announces which physical port a system is connected + to, as well as other related data. Accepts a boolean or the special value + <literal>routers-only</literal>. When true, incoming LLDP packets are accepted and a database of all LLDP + neighbors maintained. If <literal>routers-only</literal> is set only LLDP data of various types of routers + is collected and LLDP data about other types of devices ignored (such as stations, telephones and + others). If false, LLDP reception is disabled. Defaults to <literal>routers-only</literal>. Use + <citerefentry><refentrytitle>networkctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> to query the + collected neighbor data. LLDP is only available on Ethernet links. See <varname>EmitLLDP=</varname> below + for enabling LLDP packet emission from the local system. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>EmitLLDP=</varname></term> + <listitem> + <para>Controls support for Ethernet LLDP packet emission. Accepts a boolean parameter or the special values + <literal>nearest-bridge</literal>, <literal>non-tpmr-bridge</literal> and + <literal>customer-bridge</literal>. Defaults to false, which turns off LLDP packet emission. If not false, + a short LLDP packet with information about the local system is sent out in regular intervals on the + link. The LLDP packet will contain information about the local hostname, the local machine ID (as stored + in <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>) and the + local interface name, as well as the pretty hostname of the system (as set in + <citerefentry><refentrytitle>machine-info</refentrytitle><manvolnum>5</manvolnum></citerefentry>). LLDP + emission is only available on Ethernet links. Note that this setting passes data suitable for + identification of host to the network and should thus not be enabled on untrusted networks, where such + identification data should not be made available. Use this option to permit other systems to identify on + which interfaces they are connected to this system. The three special values control propagation of the + LLDP packets. The <literal>nearest-bridge</literal> setting permits propagation only to the nearest + connected bridge, <literal>non-tpmr-bridge</literal> permits propagation across Two-Port MAC Relays, but + not any other bridges, and <literal>customer-bridge</literal> permits propagation until a customer bridge + is reached. For details about these concepts, see <ulink + url="https://standards.ieee.org/findstds/standard/802.1AB-2016.html">IEEE 802.1AB-2016</ulink>. Note that + configuring this setting to true is equivalent to <literal>nearest-bridge</literal>, the recommended and + most restricted level of propagation. See <varname>LLDP=</varname> above for an option to enable LLDP + reception.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>BindCarrier=</varname></term> + <listitem> + <para>A link name or a list of link names. When set, controls the behavior of the current + link. When all links in the list are in an operational down state, the current link is brought + down. When at least one link has carrier, the current interface is brought up. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Address=</varname></term> + <listitem> + <para>A static IPv4 or IPv6 address and its prefix length, + separated by a <literal>/</literal> character. Specify + this key more than once to configure several addresses. + The format of the address must be as described in + <citerefentry project='man-pages'><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>. + This is a short-hand for an [Address] section only + containing an Address key (see below). This option may be + specified more than once. + </para> + + <para>If the specified address is <literal>0.0.0.0</literal> (for IPv4) or <literal>::</literal> + (for IPv6), a new address range of the requested size is automatically allocated from a + system-wide pool of unused ranges. Note that the prefix length must be equal or larger than 8 for + IPv4, and 64 for IPv6. The allocated range is checked against all current network interfaces and + all known network configuration files to avoid address range conflicts. The default system-wide + 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. + This functionality is useful to manage a large number of dynamically created network interfaces + with the same network configuration and automatic address range assignment.</para> + + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Gateway=</varname></term> + <listitem> + <para>The gateway address, which must be in the format + described in + <citerefentry project='man-pages'><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>. + This is a short-hand for a [Route] section only containing + a Gateway key. This option may be specified more than + once.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>DNS=</varname></term> + <listitem> + <para>A DNS server address, which must be in the format + described in + <citerefentry project='man-pages'><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>. + This option may be specified more than once. Each address can optionally take a port number + separated with <literal>:</literal>, a network interface name or index separated with + <literal>%</literal>, and a Server Name Indication (SNI) separated with <literal>#</literal>. + When IPv6 address is specified with a port number, then the address must be in the square + brackets. That is, the acceptable full formats are + <literal>111.222.333.444:9953%ifname#example.com</literal> for IPv4 and + <literal>[1111:2222::3333]:9953%ifname#example.com</literal> for IPv6. This setting can be + specified multiple times. If an empty string is assigned, then the all previous assignments + are cleared. This setting is read by + <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Domains=</varname></term> + <listitem> + <para>A whitespace-separated list of domains which should be resolved using the DNS servers on + this link. Each item in the list should be a domain name, optionally prefixed with a tilde + (<literal>~</literal>). The domains with the prefix are called "routing-only domains". The + domains without the prefix are called "search domains" and are first used as search suffixes for + extending single-label hostnames (hostnames containing no dots) to become fully qualified + domain names (FQDNs). If a single-label hostname is resolved on this interface, each of the + specified search domains are appended to it in turn, converting it into a fully qualified domain + name, until one of them may be successfully resolved.</para> + + <para>Both "search" and "routing-only" domains are used for routing of DNS queries: look-ups for hostnames + ending in those domains (hence also single label names, if any "search domains" are listed), are routed to + the DNS servers configured for this interface. The domain routing logic is particularly useful on + multi-homed hosts with DNS servers serving particular private DNS zones on each interface.</para> + + <para>The "routing-only" domain <literal>~.</literal> (the tilde indicating definition of a routing domain, + the dot referring to the DNS root domain which is the implied suffix of all valid DNS names) has special + effect. It causes all DNS traffic which does not match another configured domain routing entry to be routed + to DNS servers specified for this interface. This setting is useful to prefer a certain set of DNS servers + if a link on which they are connected is available.</para> + + <para>This setting is read by + <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>. + "Search domains" correspond to the <varname>domain</varname> and <varname>search</varname> entries in + <citerefentry project='man-pages'><refentrytitle>resolv.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>. + Domain name routing has no equivalent in the traditional glibc API, which has no concept of domain + name servers limited to a specific link.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>DNSDefaultRoute=</varname></term> + <listitem> + <para>Takes a boolean argument. If true, this link's configured DNS servers are used for resolving domain + names that do not match any link's configured <varname>Domains=</varname> setting. If false, this link's + configured DNS servers are never used for such domains, and are exclusively used for resolving names that + match at least one of the domains configured on this link. If not specified defaults to an automatic mode: + queries not matching any link's configured domains will be routed to this link if it has no routing-only + domains configured.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>NTP=</varname></term> + <listitem> + <para>An NTP server address (either an IP address, or a hostname). This option may be specified more than once. This setting is read by + <citerefentry><refentrytitle>systemd-timesyncd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>IPForward=</varname></term> + <listitem><para>Configures IP packet forwarding for the + system. If enabled, incoming packets on any network + interface will be forwarded to any other interfaces + according to the routing table. Takes a boolean, + or the values <literal>ipv4</literal> or + <literal>ipv6</literal>, which only enable IP packet + forwarding for the specified address family. This controls + the <filename>net.ipv4.ip_forward</filename> and + <filename>net.ipv6.conf.all.forwarding</filename> sysctl + options of the network interface (see <ulink + url="https://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt">ip-sysctl.txt</ulink> + for details about sysctl options). Defaults to + <literal>no</literal>.</para> + + <para>Note: this setting controls a global kernel option, + and does so one way only: if a network that has this setting + enabled is set up the global setting is turned on. However, + it is never turned off again, even after all networks with + this setting enabled are shut down again.</para> + + <para>To allow IP packet forwarding only between specific + network interfaces use a firewall.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>IPMasquerade=</varname></term> + <listitem><para>Configures IP masquerading for the network + interface. If enabled, packets forwarded from the network + interface will be appear as coming from the local host. + Takes a boolean argument. Implies + <varname>IPForward=ipv4</varname>. Defaults to + <literal>no</literal>.</para></listitem> + </varlistentry> + <varlistentry> + <term><varname>IPv6PrivacyExtensions=</varname></term> + <listitem><para>Configures use of stateless temporary + addresses that change over time (see <ulink + url="https://tools.ietf.org/html/rfc4941">RFC 4941</ulink>, + Privacy Extensions for Stateless Address Autoconfiguration + in IPv6). Takes a boolean or the special values + <literal>prefer-public</literal> and + <literal>kernel</literal>. When true, enables the privacy + extensions and prefers temporary addresses over public + addresses. When <literal>prefer-public</literal>, enables the + privacy extensions, but prefers public addresses over + temporary addresses. When false, the privacy extensions + remain disabled. When <literal>kernel</literal>, the kernel's + default setting will be left in place. Defaults to + <literal>no</literal>.</para></listitem> + </varlistentry> + <varlistentry> + <term><varname>IPv6AcceptRA=</varname></term> + <listitem><para>Takes a boolean. Controls IPv6 Router Advertisement (RA) reception support for the + interface. If true, RAs are accepted; if false, RAs are ignored. When RAs are accepted, they may + trigger the start of the DHCPv6 client if the relevant flags are set in the RA data, or if no + routers are found on the link. The default is to disable RA reception for bridge devices or when IP + forwarding is enabled, and to enable it otherwise. Cannot be enabled on bond devices and when link + local addressing is disabled.</para> + + <para>Further settings for the IPv6 RA support may be configured in the [IPv6AcceptRA] section, see + below.</para> + + <para>Also see <ulink + url="https://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt">ip-sysctl.txt</ulink> in the kernel + documentation regarding <literal>accept_ra</literal>, but note that systemd's setting of + <constant>1</constant> (i.e. true) corresponds to kernel's setting of <constant>2</constant>.</para> + + <para>Note that kernel's implementation of the IPv6 RA protocol is always disabled, + regardless of this setting. If this option is enabled, a userspace implementation of the IPv6 + RA protocol is used, and the kernel's own implementation remains disabled, since + <command>systemd-networkd</command> needs to know all details supplied in the advertisements, + and these are not available from the kernel if the kernel's own implementation is used.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>IPv6DuplicateAddressDetection=</varname></term> + <listitem><para>Configures the amount of IPv6 Duplicate + Address Detection (DAD) probes to send. When unset, the kernel's default will be used. + </para></listitem> + </varlistentry> + <varlistentry> + <term><varname>IPv6HopLimit=</varname></term> + <listitem><para>Configures IPv6 Hop Limit. For each router that + forwards the packet, the hop limit is decremented by 1. When the + hop limit field reaches zero, the packet is discarded. + When unset, the kernel's default will be used. + </para></listitem> + </varlistentry> + <varlistentry> + <term><varname>IPv4AcceptLocal=</varname></term> + <listitem><para>Takes a boolean. Accept packets with local source addresses. In combination + with suitable routing, this can be used to direct packets between two local interfaces over + the wire and have them accepted properly. When unset, the kernel's default will be used. + </para></listitem> + </varlistentry> + <varlistentry> + <term><varname>IPv4ProxyARP=</varname></term> + <listitem><para>Takes a boolean. Configures proxy ARP for IPv4. Proxy ARP is the technique in which one host, + usually a router, answers ARP requests intended for another machine. By "faking" its identity, + the router accepts responsibility for routing packets to the "real" destination. See <ulink + url="https://tools.ietf.org/html/rfc1027">RFC 1027</ulink>. + When unset, the kernel's default will be used. + </para></listitem> + </varlistentry> + <varlistentry> + <term><varname>IPv6ProxyNDP=</varname></term> + <listitem><para>Takes a boolean. Configures proxy NDP for IPv6. Proxy NDP (Neighbor Discovery + Protocol) is a technique for IPv6 to allow routing of addresses to a different + destination when peers expect them to be present on a certain physical link. + In this case a router answers Neighbour Advertisement messages intended for + another machine by offering its own MAC address as destination. + Unlike proxy ARP for IPv4, it is not enabled globally, but will only send Neighbour + Advertisement messages for addresses in the IPv6 neighbor proxy table, + which can also be shown by <command>ip -6 neighbour show proxy</command>. + systemd-networkd will control the per-interface `proxy_ndp` switch for each configured + interface depending on this option. + When unset, the kernel's default will be used. + </para></listitem> + </varlistentry> + <varlistentry> + <term><varname>IPv6ProxyNDPAddress=</varname></term> + <listitem><para>An IPv6 address, for which Neighbour Advertisement messages will be + proxied. This option may be specified more than once. systemd-networkd will add the + <option>IPv6ProxyNDPAddress=</option> entries to the kernel's IPv6 neighbor proxy table. + This option implies <option>IPv6ProxyNDP=yes</option> but has no effect if + <option>IPv6ProxyNDP</option> has been set to false. When unset, the kernel's default will be used. + </para></listitem> + </varlistentry> + <varlistentry> + <term><varname>IPv6SendRA=</varname></term> + <listitem><para>Whether to enable or disable Router Advertisement sending on a link. Takes a + boolean value. When enabled, prefixes configured in [IPv6Prefix] sections and routes + configured in [IPv6RoutePrefix] sections are distributed as defined in the [IPv6SendRA] + section. If <varname>DHCPv6PrefixDelegation=</varname> is enabled, then the delegated + prefixes are also distributed. See <varname>DHCPv6PrefixDelegation=</varname> setting and the + [IPv6SendRA], [IPv6Prefix], [IPv6RoutePrefix], and [DHCPv6PrefixDelegation] sections for more + configuration options.</para></listitem> + </varlistentry> + <varlistentry> + <term><varname>DHCPv6PrefixDelegation=</varname></term> + <listitem><para>Takes a boolean value. When enabled, requests prefixes using a DHCPv6 client + configured on another link. By default, an address within each delegated prefix will be + assigned, and the prefixes will be announced through IPv6 Router Advertisement when + <varname>IPv6SendRA=</varname> is enabled. Such default settings can be configured in + [DHCPv6PrefixDelegation] section. Defaults to disabled.</para></listitem> + </varlistentry> + <varlistentry> + <term><varname>IPv6MTUBytes=</varname></term> + <listitem><para>Configures IPv6 maximum transmission unit (MTU). + An integer greater than or equal to 1280 bytes. When unset, the kernel's default will be used. + </para></listitem> + </varlistentry> + <varlistentry> + <term><varname>Bridge=</varname></term> + <listitem> + <para>The name of the bridge to add the link to. See + <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Bond=</varname></term> + <listitem> + <para>The name of the bond to add the link to. See + <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>VRF=</varname></term> + <listitem> + <para>The name of the VRF to add the link to. See + <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>VLAN=</varname></term> + <listitem> + <para>The name of a VLAN to create on the link. See + <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>. + This option may be specified more than once.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>IPVLAN=</varname></term> + <listitem> + <para>The name of a IPVLAN to create on the link. See + <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>. + This option may be specified more than once.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>MACVLAN=</varname></term> + <listitem> + <para>The name of a MACVLAN to create on the link. See + <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>. + This option may be specified more than once.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>VXLAN=</varname></term> + <listitem> + <para>The name of a VXLAN to create on the link. See + <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>. + This option may be specified more than once.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Tunnel=</varname></term> + <listitem> + <para>The name of a Tunnel to create on the link. See + <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>. + This option may be specified more than once.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>MACsec=</varname></term> + <listitem> + <para>The name of a MACsec device to create on the link. See + <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>. + This option may be specified more than once.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>ActiveSlave=</varname></term> + <listitem> + <para>Takes a boolean. Specifies the new active slave. The <literal>ActiveSlave=</literal> + option is only valid for following modes: + <literal>active-backup</literal>, + <literal>balance-alb</literal> and + <literal>balance-tlb</literal>. Defaults to false. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>PrimarySlave=</varname></term> + <listitem> + <para>Takes a boolean. Specifies which slave is the primary device. The specified + device will always be the active slave while it is available. Only when the + primary is off-line will alternate devices be used. This is useful when + one slave is preferred over another, e.g. when one slave has higher throughput + than another. The <literal>PrimarySlave=</literal> option is only valid for + following modes: + <literal>active-backup</literal>, + <literal>balance-alb</literal> and + <literal>balance-tlb</literal>. Defaults to false. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>ConfigureWithoutCarrier=</varname></term> + <listitem> + <para>Takes a boolean. Allows networkd to configure a specific link even if it has no carrier. + Defaults to false. If <option>IgnoreCarrierLoss=</option> is not explicitly set, it will + default to this value. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>IgnoreCarrierLoss=</varname></term> + <listitem> + <para>Takes a boolean. Allows networkd to retain both the static and dynamic configuration + of the interface even if its carrier is lost. When unset, the value specified with + <option>ConfigureWithoutCarrier=</option> is used. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Xfrm=</varname></term> + <listitem> + <para>The name of the xfrm to create on the link. See + <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>. + This option may be specified more than once.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>KeepConfiguration=</varname></term> + <listitem> + <para>Takes a boolean or one of <literal>static</literal>, <literal>dhcp-on-stop</literal>, + <literal>dhcp</literal>. When <literal>static</literal>, <command>systemd-networkd</command> + will not drop static addresses and routes on starting up process. When set to + <literal>dhcp-on-stop</literal>, <command>systemd-networkd</command> will not drop addresses + and routes on stopping the daemon. When <literal>dhcp</literal>, + the addresses and routes provided by a DHCP server will never be dropped even if the DHCP + lease expires. This is contrary to the DHCP specification, but may be the best choice if, + e.g., the root filesystem relies on this connection. The setting <literal>dhcp</literal> + implies <literal>dhcp-on-stop</literal>, and <literal>yes</literal> implies + <literal>dhcp</literal> and <literal>static</literal>. Defaults to <literal>no</literal>. + </para> + </listitem> + </varlistentry> + + </variablelist> + + </refsect1> + + <refsect1> + <title>[Address] Section Options</title> + + <para>An [Address] section accepts the following keys. Specify several [Address] + sections to configure several addresses.</para> + + <variablelist class='network-directives'> + <varlistentry> + <term><varname>Address=</varname></term> + <listitem> + <para>As in the [Network] section. This key is mandatory. Each [Address] section can contain one + <varname>Address=</varname> setting.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Peer=</varname></term> + <listitem> + <para>The peer address in a point-to-point connection. + Accepts the same format as the <varname>Address=</varname> + key.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Broadcast=</varname></term> + <listitem> + <para>The broadcast address, which must be in the format + described in + <citerefentry project='man-pages'><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>. + This key only applies to IPv4 addresses. If it is not + given, it is derived from the <varname>Address=</varname> + key.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Label=</varname></term> + <listitem> + <para>An address label.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>PreferredLifetime=</varname></term> + <listitem> + <para>Allows the default "preferred lifetime" of the address to be overridden. + Only three settings are accepted: <literal>forever</literal> or <literal>infinity</literal> + which is the default and means that the address never expires, and <literal>0</literal> which means + that the address is considered immediately "expired" and will not be used, + unless explicitly requested. A setting of PreferredLifetime=0 is useful for + addresses which are added to be used only by a specific application, + which is then configured to use them explicitly.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Scope=</varname></term> + <listitem> + <para>The scope of the address, which can be + <literal>global</literal> (valid everywhere on the network, even through a gateway), + <literal>link</literal> (only valid on this device, will not traverse a gateway) or + <literal>host</literal> (only valid within the device itself, e.g. 127.0.0.1) + or an unsigned integer in the range 0—255. + Defaults to <literal>global</literal>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>HomeAddress=</varname></term> + <listitem> + <para>Takes a boolean. Designates this address the "home address" as defined in + <ulink url="https://tools.ietf.org/html/rfc6275">RFC 6275</ulink>. + Supported only on IPv6. Defaults to false.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>DuplicateAddressDetection=</varname></term> + <listitem> + <para>Takes one of <literal>ipv4</literal>, <literal>ipv6</literal>, + <literal>both</literal>, <literal>none</literal>. When <literal>ipv4</literal>, + performs IPv4 Duplicate Address Detection. See + <ulink url="https://tools.ietf.org/html/rfc5227">RFC 5224</ulink>. + When <literal>ipv6</literal>, performs IPv6 Duplicate Address Detection. See + <ulink url="https://tools.ietf.org/html/rfc4862">RFC 4862</ulink>. + Defaults to <literal>ipv6</literal>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>ManageTemporaryAddress=</varname></term> + <listitem> + <para>Takes a boolean. If true the kernel manage temporary addresses created + from this one as template on behalf of Privacy Extensions + <ulink url="https://tools.ietf.org/html/rfc3041">RFC 3041</ulink>. For this to become + active, the use_tempaddr sysctl setting has to be set to a value greater than zero. + The given address needs to have a prefix length of 64. This flag allows using privacy + extensions in a manually configured network, just like if stateless auto-configuration + was active. Defaults to false. </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>AddPrefixRoute=</varname></term> + <listitem> + <para>Takes a boolean. When true, the prefix route for the address is automatically added. + Defaults to true.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>AutoJoin=</varname></term> + <listitem> + <para>Takes a boolean. Joining multicast group on ethernet level via + <command>ip maddr</command> command would not work if we have an Ethernet switch that does + IGMP snooping since the switch would not replicate multicast packets on ports that did not + have IGMP reports for the multicast addresses. Linux vxlan interfaces created via + <command>ip link add vxlan</command> or networkd's netdev kind vxlan have the group option + that enables then to do the required join. By extending ip address command with option + <literal>autojoin</literal> we can get similar functionality for openvswitch (OVS) vxlan + interfaces as well as other tunneling mechanisms that need to receive multicast traffic. + Defaults to <literal>no</literal>.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[Neighbor] Section Options</title> + <para>A [Neighbor] section accepts the following keys. The neighbor section adds a permanent, static + entry to the neighbor table (IPv6) or ARP table (IPv4) for the given hardware address on the links + matched for the network. Specify several [Neighbor] sections to configure several static neighbors. + </para> + + <variablelist class='network-directives'> + <varlistentry> + <term><varname>Address=</varname></term> + <listitem> + <para>The IP address of the neighbor.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>LinkLayerAddress=</varname></term> + <listitem> + <para>The link layer address (MAC address or IP address) of the neighbor.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[IPv6AddressLabel] Section Options</title> + + <para>An [IPv6AddressLabel] section accepts the following keys. Specify several [IPv6AddressLabel] + sections to configure several address labels. IPv6 address labels are used for address selection. See + <ulink url="https://tools.ietf.org/html/rfc3484">RFC 3484</ulink>. Precedence is managed by userspace, + and only the label itself is stored in the kernel.</para> + + <variablelist class='network-directives'> + <varlistentry> + <term><varname>Label=</varname></term> + <listitem> + <para>The label for the prefix, an unsigned integer in the range 0–4294967294. + 0xffffffff is reserved. This setting is mandatory.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Prefix=</varname></term> + <listitem> + <para>IPv6 prefix is an address with a prefix length, separated by a slash <literal>/</literal> character. + This key is mandatory. </para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[RoutingPolicyRule] Section Options</title> + + <para>An [RoutingPolicyRule] section accepts the following keys. Specify several [RoutingPolicyRule] + sections to configure several rules.</para> + + <variablelist class='network-directives'> + <varlistentry> + <term><varname>TypeOfService=</varname></term> + <listitem> + <para>Takes a number between 0 and 255 that specifies the type of service to match.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>From=</varname></term> + <listitem> + <para>Specifies the source address prefix to match. Possibly followed by a slash and the prefix length.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>To=</varname></term> + <listitem> + <para>Specifies the destination address prefix to match. Possibly followed by a slash and the prefix length.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>FirewallMark=</varname></term> + <listitem> + <para>Specifies the iptables firewall mark value to match (a number between 1 and + 4294967295). Optionally, the firewall mask (also a number between 1 and 4294967295) can be + suffixed with a slash (<literal>/</literal>), e.g., <literal>7/255</literal>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Table=</varname></term> + <listitem> + <para>Specifies the routing table identifier to lookup if the rule selector matches. Takes + one of <literal>default</literal>, <literal>main</literal>, and <literal>local</literal>, + or a number between 1 and 4294967295. Defaults to <literal>main</literal>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Priority=</varname></term> + <listitem> + <para>Specifies the priority of this rule. <varname>Priority=</varname> is an unsigned + integer. Higher number means lower priority, and rules get processed in order of increasing number.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>IncomingInterface=</varname></term> + <listitem> + <para>Specifies incoming device to match. If the interface is loopback, the rule only matches packets originating from this host.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>OutgoingInterface=</varname></term> + <listitem> + <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> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>SourcePort=</varname></term> + <listitem> + <para>Specifies the source IP port or IP port range match in forwarding information base (FIB) rules. + A port range is specified by the lower and upper port separated by a dash. Defaults to unset.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>DestinationPort=</varname></term> + <listitem> + <para>Specifies the destination IP port or IP port range match in forwarding information base (FIB) rules. + A port range is specified by the lower and upper port separated by a dash. Defaults to unset.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>IPProtocol=</varname></term> + <listitem> + <para>Specifies the IP protocol to match in forwarding information base (FIB) rules. Takes IP protocol name such as <literal>tcp</literal>, + <literal>udp</literal> or <literal>sctp</literal>, or IP protocol number such as <literal>6</literal> for <literal>tcp</literal> or + <literal>17</literal> for <literal>udp</literal>. + Defaults to unset.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>InvertRule=</varname></term> + <listitem> + <para>A boolean. Specifies whether the rule is to be inverted. Defaults to false.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Family=</varname></term> + <listitem> + <para>Takes a special value <literal>ipv4</literal>, <literal>ipv6</literal>, or + <literal>both</literal>. By default, the address family is determined by the address + specified in <varname>To=</varname> or <varname>From=</varname>. If neither + <varname>To=</varname> nor <varname>From=</varname> are specified, then defaults to + <literal>ipv4</literal>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>User=</varname></term> + <listitem> + <para>Takes a username, a user ID, or a range of user IDs separated by a dash. Defaults to + unset.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>SuppressPrefixLength=</varname></term> + <listitem> + <para>Takes a number <replaceable>N</replaceable> in the range 0-128 and rejects routing + decisions that have a prefix length of <replaceable>N</replaceable> or less. Defaults to + unset.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[NextHop] Section Options</title> + <para>The [NextHop] section is used to manipulate entries in the kernel's "nexthop" tables. The + [NextHop] section accepts the following keys. Specify several [NextHop] sections to configure several + hops.</para> + + <variablelist class='network-directives'> + <varlistentry> + <term><varname>Gateway=</varname></term> + <listitem> + <para>As in the [Network] section. This is mandatory.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Id=</varname></term> + <listitem> + <para>The id of the nexthop (an unsigned integer). If unspecified or '0' then automatically chosen by kernel.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[Route] Section Options</title> + <para>The [Route] section accepts the following keys. Specify several [Route] sections to configure + several routes.</para> + + <variablelist class='network-directives'> + <varlistentry> + <term><varname>Gateway=</varname></term> + <listitem> + <para>Takes the gateway address or the special values <literal>_dhcp4</literal> and + <literal>_ipv6ra</literal>. If <literal>_dhcp4</literal> or <literal>_ipv6ra</literal> is + set, then the gateway address provided by DHCPv4 or IPv6 RA is used.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>GatewayOnLink=</varname></term> + <listitem> + <para>Takes a boolean. If set to true, the kernel does not have + to check if the gateway is reachable directly by the current machine (i.e., the kernel does + not need to check if the gateway is attached to the local network), so that we can insert the + route in the kernel table without it being complained about. Defaults to <literal>no</literal>. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Destination=</varname></term> + <listitem> + <para>The destination prefix of the route. Possibly + followed by a slash and the prefix length. If omitted, a + full-length host route is assumed.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Source=</varname></term> + <listitem> + <para>The source prefix of the route. Possibly followed by + a slash and the prefix length. If omitted, a full-length + host route is assumed.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Metric=</varname></term> + <listitem> + <para>The metric of the route (an unsigned integer).</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>IPv6Preference=</varname></term> + <listitem> + <para>Specifies the route preference as defined in <ulink + url="https://tools.ietf.org/html/rfc4191">RFC 4191</ulink> for Router Discovery messages. Which + can be one of <literal>low</literal> the route has a lowest priority, <literal>medium</literal> + the route has a default priority or <literal>high</literal> the route has a highest priority. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Scope=</varname></term> + <listitem> + <para>The scope of the IPv4 route, which can be <literal>global</literal>, <literal>site</literal>, + <literal>link</literal>, <literal>host</literal>, or + <literal>nowhere</literal>:</para> + <itemizedlist> + <listitem><para><literal>global</literal> means the route can reach + hosts more than one hop away.</para></listitem> + + <listitem><para><literal>site</literal> means an interior route in + the local autonomous system.</para></listitem> + + <listitem><para><literal>link</literal> means the route can only + reach hosts on the local network (one hop away).</para></listitem> + + <listitem><para><literal>host</literal> means the route will not + leave the local machine (used for internal addresses like + 127.0.0.1).</para></listitem> + + <listitem><para><literal>nowhere</literal> means the destination + doesn't exist.</para></listitem> + </itemizedlist> + <para>For IPv4 route, defaults to <literal>host</literal> if <varname>Type=</varname> is + <literal>local</literal> or <literal>nat</literal>, + and <literal>link</literal> if <varname>Type=</varname> is + <literal>broadcast</literal>, <literal>multicast</literal>, or <literal>anycast</literal>. + In other cases, defaults to <literal>global</literal>. The value is + not used for IPv6.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>PreferredSource=</varname></term> + <listitem> + <para>The preferred source address of the route. The address + must be in the format described in + <citerefentry project='man-pages'><refentrytitle>inet_pton</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Table=</varname></term> + <listitem> + <para>The table identifier for the route. Takes <literal>default</literal>, + <literal>main</literal>, <literal>local</literal> or a number between 1 and 4294967295. + The table can be retrieved using <command>ip route show table <replaceable>num</replaceable></command>. + If unset and <varname>Type=</varname> is <literal>local</literal>, <literal>broadcast</literal>, + <literal>anycast</literal>, or <literal>nat</literal>, then <literal>local</literal> is used. + In other cases, defaults to <literal>main</literal>. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Protocol=</varname></term> + <listitem> + <para>The protocol identifier for the route. Takes a number between 0 and 255 or the special values + <literal>kernel</literal>, <literal>boot</literal>, <literal>static</literal>, + <literal>ra</literal> and <literal>dhcp</literal>. Defaults to <literal>static</literal>. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Type=</varname></term> + <listitem> + <para>Specifies the type for the route. Takes one of <literal>unicast</literal>, + <literal>local</literal>, <literal>broadcast</literal>, <literal>anycast</literal>, + <literal>multicast</literal>, <literal>blackhole</literal>, <literal>unreachable</literal>, + <literal>prohibit</literal>, <literal>throw</literal>, <literal>nat</literal>, and + <literal>xresolve</literal>. If <literal>unicast</literal>, a regular route is defined, i.e. a + route indicating the path to take to a destination network address. If <literal>blackhole</literal>, packets + to the defined route are discarded silently. If <literal>unreachable</literal>, packets to the defined route + are discarded and the ICMP message "Host Unreachable" is generated. If <literal>prohibit</literal>, packets + to the defined route are discarded and the ICMP message "Communication Administratively Prohibited" is + generated. If <literal>throw</literal>, route lookup in the current routing table will fail and the route + selection process will return to Routing Policy Database (RPDB). Defaults to <literal>unicast</literal>. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>InitialCongestionWindow=</varname></term> + <listitem> + <para>The TCP initial congestion window is used during the start of a TCP connection. + During the start of a TCP session, when a client requests a resource, the server's initial + congestion window determines how many packets will be sent during the initial burst of data + without waiting for acknowledgement. Takes a number between 1 and 1023. Note that 100 is + considered an extremely large value for this option. When unset, the kernel's default + (typically 10) will be used.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>InitialAdvertisedReceiveWindow=</varname></term> + <listitem> + <para>The TCP initial advertised receive window is the amount of receive data (in bytes) + that can initially be buffered at one time on a connection. The sending host can send only + that amount of data before waiting for an acknowledgment and window update from the + receiving host. Takes a number between 1 and 1023. Note that 100 is considered an extremely + large value for this option. When unset, the kernel's default will be used.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>QuickAck=</varname></term> + <listitem> + <para>Takes a boolean. When true enables TCP quick ack mode for the route. When unset, the kernel's default will be used. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>FastOpenNoCookie=</varname></term> + <listitem> + <para>Takes a boolean. When true enables TCP fastopen without a cookie on a per-route basis. + When unset, the kernel's default will be used. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>TTLPropagate=</varname></term> + <listitem> + <para>Takes a boolean. When true enables TTL propagation at Label Switched Path (LSP) egress. + When unset, the kernel's default will be used. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>MTUBytes=</varname></term> + <listitem> + <para>The maximum transmission unit in bytes to set for the + route. The usual suffixes K, M, G, are supported and are + understood to the base of 1024.</para> + <para>Note that if IPv6 is enabled on the interface, and the MTU is chosen + below 1280 (the minimum MTU for IPv6) it will automatically be increased to this value.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>IPServiceType=</varname></term> + <listitem> + <para>Takes string; <literal>CS6</literal> or <literal>CS4</literal>. Used to set IP + service type to CS6 (network control) or CS4 (Realtime). Defaults to CS6.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>MultiPathRoute=<replaceable>address</replaceable>[@<replaceable>name</replaceable>] [<replaceable>weight</replaceable>]</varname></term> + <listitem> + <para>Configures multipath route. Multipath routing is the technique of using multiple + alternative paths through a network. Takes gateway address. Optionally, takes a network + interface name or index separated with <literal>@</literal>, and a weight in 1..256 for + this multipath route separated with whitespace. This setting can be specified multiple + times. If an empty string is assigned, then the all previous assignments are cleared.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[DHCPv4] Section Options</title> + <para>The [DHCPv4] section configures the DHCPv4 client, if it is enabled with the + <varname>DHCP=</varname> setting described above:</para> + + <variablelist class='network-directives'> + <varlistentry> + <term><varname>UseDNS=</varname></term> + <listitem> + <para>When true (the default), the DNS servers received + from the DHCP server will be used and take precedence over + any statically configured ones.</para> + + <para>This corresponds to the <option>nameserver</option> + option in <citerefentry + project='man-pages'><refentrytitle>resolv.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>RoutesToDNS=</varname></term> + <listitem> + <para>When true, the routes to the DNS servers received from the DHCP server will be + configured. When <varname>UseDNS=</varname> is disabled, this setting is ignored. + Defaults to false.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>UseNTP=</varname></term> + <listitem> + <para>When true (the default), the NTP servers received from the DHCP server will be used by + <filename>systemd-timesyncd.service</filename> and take precedence over any statically configured + ones.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>UseSIP=</varname></term> + <listitem> + <para>When true (the default), the SIP servers received from the DHCP server will be collected + and made available to client programs.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>UseMTU=</varname></term> + <listitem> + <para>When true, the interface maximum transmission unit + from the DHCP server will be used on the current link. + If <varname>MTUBytes=</varname> is set, then this setting is ignored. + Defaults to false.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Anonymize=</varname></term> + <listitem> + <para>Takes a boolean. When true, the options sent to the DHCP server will + follow the <ulink url="https://tools.ietf.org/html/rfc7844">RFC 7844</ulink> + (Anonymity Profiles for DHCP Clients) to minimize disclosure of identifying information. + Defaults to false.</para> + + <para>This option should only be set to true when + <varname>MACAddressPolicy=</varname> is set to <literal>random</literal> + (see <citerefentry + project='man-pages'><refentrytitle>systemd.link</refentrytitle><manvolnum>5</manvolnum></citerefentry>).</para> + + <para>Note that this configuration will overwrite others. + In concrete, the following variables will be ignored: + <varname>SendHostname=</varname>, <varname>ClientIdentifier=</varname>, + <varname>UseRoutes=</varname>, <varname>UseMTU=</varname>, + <varname>VendorClassIdentifier=</varname>, <varname>UseTimezone=</varname>.</para> + + <para>With this option enabled DHCP requests will mimic those generated by Microsoft Windows, in + order to reduce the ability to fingerprint and recognize installations. This means DHCP request + sizes will grow and lease data will be more comprehensive than normally, though most of the + requested data is not actually used.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>SendHostname=</varname></term> + <listitem> + <para>When true (the default), the machine's hostname will be sent to the DHCP server. + Note that the machine's hostname must consist only of 7-bit ASCII lower-case characters and + no spaces or dots, and be formatted as a valid DNS domain name. Otherwise, the hostname is not + sent even if this is set to true.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>MUDURL=</varname></term> + <listitem> + <para>When configured, the specified Manufacturer Usage Description (MUD) URL will be sent to the + DHCPv4 server. Takes a URL of length up to 255 characters. A superficial verification that the + string is a valid URL will be performed. DHCPv4 clients are intended to have at most one MUD URL + associated with them. See <ulink url="https://tools.ietf.org/html/rfc8520">RFC 8520</ulink>. + </para> + + <para>MUD is an embedded software standard defined by the IETF that allows IoT device makers to + advertise device specifications, including the intended communication patterns for their device + when it connects to the network. The network can then use this to author a context-specific + access policy, so the device functions only within those parameters.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>UseHostname=</varname></term> + <listitem> + <para>When true (the default), the hostname received from + the DHCP server will be set as the transient hostname of the system. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Hostname=</varname></term> + <listitem> + <para>Use this value for the hostname which is sent to the DHCP server, instead of machine's hostname. + Note that the specified hostname must consist only of 7-bit ASCII lower-case characters and + no spaces or dots, and be formatted as a valid DNS domain name.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>UseDomains=</varname></term> + <listitem> + <para>Takes a boolean, or the special value <literal>route</literal>. When true, the domain name + received from the DHCP server will be used as DNS search domain over this link, similar to the effect of + the <option>Domains=</option> setting. If set to <literal>route</literal>, the domain name received from + the DHCP server will be used for routing DNS queries only, but not for searching, similar to the effect of + the <option>Domains=</option> setting when the argument is prefixed with <literal>~</literal>. Defaults to + false.</para> + + <para>It is recommended to enable this option only on trusted networks, as setting this affects resolution + of all hostnames, in particular of single-label names. It is generally safer to use the supplied domain + only as routing domain, rather than as search domain, in order to not have it affect local resolution of + single-label names.</para> + + <para>When set to true, this setting corresponds to the <option>domain</option> option in <citerefentry + project='man-pages'><refentrytitle>resolv.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>UseRoutes=</varname></term> + <listitem> + <para>When true (the default), the static routes will be requested from the DHCP server and added to the + routing table with a metric of 1024, and a scope of "global", "link" or "host", depending on the route's + destination and gateway. If the destination is on the local host, e.g., 127.x.x.x, or the same as the + link's own address, the scope will be set to "host". Otherwise if the gateway is null (a direct route), a + "link" scope will be used. For anything else, scope defaults to "global".</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>UseGateway=</varname></term> + <listitem> + <para>When true, the gateway will be requested from the DHCP server and added to the routing table with a + metric of 1024, and a scope of "link". When unset, the value specified with <option>UseRoutes=</option> + is used.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>UseTimezone=</varname></term> + + <listitem><para>When true, the timezone received from the + DHCP server will be set as timezone of the local + system. Defaults to <literal>no</literal>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>ClientIdentifier=</varname></term> + <listitem> + <para>The DHCPv4 client identifier to use. Takes one of <literal>mac</literal>, <literal>duid</literal> or <literal>duid-only</literal>. + If set to <literal>mac</literal>, the MAC address of the link is used. + If set to <literal>duid</literal>, an RFC4361-compliant Client ID, which is the combination of IAID and DUID (see below), is used. + 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. + Defaults to <literal>duid</literal>.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>VendorClassIdentifier=</varname></term> + <listitem> + <para>The vendor class identifier used to identify vendor + type and configuration.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>UserClass=</varname></term> + <listitem> + <para>A DHCPv4 client can use UserClass option to identify the type or category of user or applications + it represents. The information contained in this option is a string that represents the user class of which + the client is a member. Each class sets an identifying string of information to be used by the DHCP + service to classify clients. Takes a whitespace-separated list of strings.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>MaxAttempts=</varname></term> + <listitem> + <para>Specifies how many times the DHCPv4 client configuration should be attempted. Takes a + number or <literal>infinity</literal>. Defaults to <literal>infinity</literal>. + Note that the time between retries is increased exponentially, so the network will not be + overloaded even if this number is high.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>DUIDType=</varname></term> + <listitem> + <para>Override the global <varname>DUIDType</varname> setting for this network. See + <citerefentry><refentrytitle>networkd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry> + for a description of possible values.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>DUIDRawData=</varname></term> + <listitem> + <para>Override the global <varname>DUIDRawData</varname> setting for this network. See + <citerefentry><refentrytitle>networkd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry> + for a description of possible values.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>IAID=</varname></term> + <listitem> + <para>The DHCP Identity Association Identifier (IAID) for the interface, a 32-bit unsigned integer.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>RequestBroadcast=</varname></term> + <listitem> + <para>Request the server to use broadcast messages before + the IP address has been configured. This is necessary for + devices that cannot receive RAW packets, or that cannot + receive packets at all before an IP address has been + configured. On the other hand, this must not be enabled on + networks where broadcasts are filtered out.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>RouteMetric=</varname></term> + <listitem> + <para>Set the routing metric for routes specified by the DHCP server. Defaults to 1024.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>RouteTable=<replaceable>num</replaceable></varname></term> + <listitem> + <para>The table identifier for DHCP routes (a number between 1 and 4294967295, or 0 to unset). + The table can be retrieved using <command>ip route show table <replaceable>num</replaceable></command>. + </para> + <para>When used in combination with <varname>VRF=</varname>, the + VRF's routing table is used when this parameter is not specified. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>RouteMTUBytes=</varname></term> + <listitem> + <para>Specifies the MTU for the DHCP routes. Please see the [Route] section for further details.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>ListenPort=</varname></term> + <listitem> + <para>Allow setting custom port for the DHCP client to listen on.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>FallbackLeaseLifetimeSec=</varname></term> + <listitem> + <para>Allows to set DHCPv4 lease lifetime when DHCPv4 server does not send the lease lifetime. + Takes one of <literal>forever</literal> or <literal>infinity</literal> means that the address + never expires. Defaults to unset.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>SendRelease=</varname></term> + <listitem> + <para>When true, the DHCPv4 client sends a DHCP release packet when it stops. + Defaults to true.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>SendDecline=</varname></term> + <listitem> + <para>A boolean. When <literal>true</literal>, the DHCPv4 client receives the IP address from the + DHCP server. After a new IP is received, the DHCPv4 client performs IPv4 Duplicate Address + Detection. If duplicate use is detected, the DHCPv4 client rejects the IP by sending a + DHCPDECLINE packet and tries to obtain an IP address again. See <ulink + url="https://tools.ietf.org/html/rfc5227">RFC 5224</ulink>. Defaults to + <literal>unset</literal>.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>DenyList=</varname></term> + <listitem> + <para>A whitespace-separated list of IPv4 addresses. DHCP offers from servers in the list are rejected. Note that + if <varname>AllowList=</varname> is configured then <varname>DenyList=</varname> is ignored.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>AllowList=</varname></term> + <listitem> + <para>A whitespace-separated list of IPv4 addresses. DHCP offers from servers in the list are accepted.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>RequestOptions=</varname></term> + <listitem> + <para>When configured, allows to set arbitrary request options in the DHCPv4 request options list and will be + sent to the DHCPV4 server. A whitespace-separated list of integers in the range 1..254. Defaults to unset.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>SendOption=</varname></term> + <listitem> + <para>Send an arbitrary raw option in the DHCPv4 request. Takes a DHCP option number, data type + and data separated with a colon + (<literal><replaceable>option</replaceable>:<replaceable>type</replaceable>:<replaceable>value</replaceable></literal>). + The option number must be an integer in the range 1..254. The type takes one of <literal>uint8</literal>, + <literal>uint16</literal>, <literal>uint32</literal>, <literal>ipv4address</literal>, or + <literal>string</literal>. Special characters in the data string may be escaped using + <ulink url="https://en.wikipedia.org/wiki/Escape_sequences_in_C#Table_of_escape_sequences">C-style + escapes</ulink>. This setting can be specified multiple times. If an empty string is specified, + then all options specified earlier are cleared. Defaults to unset.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>SendVendorOption=</varname></term> + <listitem> + <para>Send an arbitrary vendor option in the DHCPv4 request. Takes a DHCP option number, data type + and data separated with a colon + (<literal><replaceable>option</replaceable>:<replaceable>type</replaceable>:<replaceable>value</replaceable></literal>). + The option number must be an integer in the range 1..254. The type takes one of <literal>uint8</literal>, + <literal>uint16</literal>, <literal>uint32</literal>, <literal>ipv4address</literal>, or + <literal>string</literal>. Special characters in the data string may be escaped using + <ulink url="https://en.wikipedia.org/wiki/Escape_sequences_in_C#Table_of_escape_sequences">C-style + escapes</ulink>. This setting can be specified multiple times. If an empty string is specified, + then all options specified earlier are cleared. Defaults to unset.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[DHCPv6] Section Options</title> + <para>The [DHCPv6] section configures the DHCPv6 client, if it is enabled with the + <varname>DHCP=</varname> setting described above, or invoked by the IPv6 Router Advertisement:</para> + + <variablelist class='network-directives'> + <varlistentry> + <term><varname>UseDNS=</varname></term> + <term><varname>UseNTP=</varname></term> + <listitem> + <para>As in the [DHCPv4] section.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>RouteMetric=</varname></term> + <listitem> + <para>Set the routing metric for routes specified by the DHCP server. Defaults to 1024.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>RapidCommit=</varname></term> + <listitem> + <para>Takes a boolean. The DHCPv6 client can obtain configuration parameters from a DHCPv6 server through + a rapid two-message exchange (solicit and reply). When the rapid commit option is enabled by both + the DHCPv6 client and the DHCPv6 server, the two-message exchange is used, rather than the default + four-message exchange (solicit, advertise, request, and reply). The two-message exchange provides + faster client configuration and is beneficial in environments in which networks are under a heavy load. + See <ulink url="https://tools.ietf.org/html/rfc3315#section-17.2.1">RFC 3315</ulink> for details. + Defaults to true.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>MUDURL=</varname></term> + <listitem> + <para>When configured, the specified Manufacturer Usage Description (MUD) URL will be sent to + the DHCPV6 server. The syntax and semantics are the same as for <varname>MUDURL=</varname> in the + [DHCPv4] section described above.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>RequestOptions=</varname></term> + <listitem> + <para>When configured, allows to set arbitrary request options in the DHCPv6 request options list + that will be sent to the DHCPV6 server. A whitespace-separated list of integers in the range + 1..254. Defaults to unset.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>SendVendorOption=</varname></term> + <listitem> + <para>Send an arbitrary vendor option in the DHCPv6 request. Takes an enterprise identifier, DHCP + option number, data type, and data separated with a colon (<literal><replaceable>enterprise + identifier</replaceable>:<replaceable>option</replaceable>:<replaceable>type</replaceable>: + <replaceable>value</replaceable></literal>). Enterprise identifier is an unsigned integer in the + range 1–4294967294. The option number must be an integer in the range 1–254. Data type takes one + of <literal>uint8</literal>, <literal>uint16</literal>, <literal>uint32</literal>, + <literal>ipv4address</literal>, <literal>ipv6address</literal>, or + <literal>string</literal>. Special characters in the data string may be escaped using <ulink + url="https://en.wikipedia.org/wiki/Escape_sequences_in_C#Table_of_escape_sequences">C-style + escapes</ulink>. This setting can be specified multiple times. If an empty string is specified, + then all options specified earlier are cleared. Defaults to unset.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>ForceDHCPv6PDOtherInformation=</varname></term> + <listitem> + <para>Takes a boolean that enforces DHCPv6 stateful mode when the 'Other information' bit is set in + Router Advertisement messages. By default setting only the 'O' bit in Router Advertisements + makes DHCPv6 request network information in a stateless manner using a two-message Information + Request and Information Reply message exchange. + <ulink url="https://tools.ietf.org/html/rfc7084">RFC 7084</ulink>, requirement WPD-4, updates + this behavior for a Customer Edge router so that stateful DHCPv6 Prefix Delegation is also + requested when only the 'O' bit is set in Router Advertisements. This option enables such a CE + behavior as it is impossible to automatically distinguish the intention of the 'O' bit otherwise. + By default this option is set to 'false', enable it if no prefixes are delegated when the device + should be acting as a CE router.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>PrefixDelegationHint=</varname></term> + <listitem> + <para>Takes an IPv6 address with prefix length in the same format as the + <varname>Address=</varname> in the [Network] section. The DHCPv6 client will include a prefix + hint in the DHCPv6 solicitation sent to the server. The prefix length must be in the range + 1–128. Defaults to unset.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>WithoutRA=</varname></term> + <listitem> + <para>Allows DHCPv6 client to start without router advertisements's managed or other address + configuration flag. Takes one of <literal>solicit</literal> or + <literal>information-request</literal>. Defaults to unset.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>SendOption=</varname></term> + <listitem> + <para>As in the [DHCPv4] section, however because DHCPv6 uses 16-bit fields to store + option numbers, the option number is an integer in the range 1..65536.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>UserClass=</varname></term> + <listitem> + <para>A DHCPv6 client can use User Class option to identify the type or category of user or applications + it represents. The information contained in this option is a string that represents the user class of which + the client is a member. Each class sets an identifying string of information to be used by the DHCP + service to classify clients. Special characters in the data string may be escaped using + <ulink url="https://en.wikipedia.org/wiki/Escape_sequences_in_C#Table_of_escape_sequences">C-style + escapes</ulink>. This setting can be specified multiple times. If an empty string is specified, + then all options specified earlier are cleared. Takes a whitespace-separated list of strings. Note that + currently <constant>NUL</constant> bytes are not allowed.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>VendorClass=</varname></term> + <listitem> + <para>A DHCPv6 client can use VendorClass option to identify the vendor that + manufactured the hardware on which the client is running. The information + contained in the data area of this option is contained in one or more opaque + fields that identify details of the hardware configuration. Takes a + whitespace-separated list of strings.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[DHCPv6PrefixDelegation] Section Options</title> + <para>The [DHCPv6PrefixDelegation] section configures delegated prefixes assigned by DHCPv6 server. + The settings in this section are used only when <varname>DHCPv6PrefixDelegation=</varname> setting + is enabled.</para> + + <variablelist class='network-directives'> + <varlistentry> + <term><varname>SubnetId=</varname></term> + <listitem> + <para>Configure a specific subnet ID on the interface from a (previously) received prefix + delegation. You can either set "auto" (the default) or a specific subnet ID (as defined in + <ulink url="https://tools.ietf.org/html/rfc4291#section-2.5.4">RFC 4291</ulink>, section + 2.5.4), in which case the allowed value is hexadecimal, from 0 to 0x7fffffffffffffff + inclusive.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>Announce=</varname></term> + <listitem> + <para>Takes a boolean. When enabled, and <varname>IPv6SendRA=</varname> in [Network] section + is enabled, the delegated prefixes are distributed through the IPv6 Router Advertisement. + Defaults to yes.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>Assign=</varname></term> + <listitem> + <para>Takes a boolean. Specifies whether to add an address from the delegated prefixes which + are received from the WAN interface by the DHCPv6 Prefix Delegation. When true (on LAN + interfce), the EUI-64 algorithm will be used by default to form an interface identifier from + the delegated prefixes. See also <varname>Token=</varname> setting below. Defaults to yes. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>Token=</varname></term> + <listitem> + <para>Specifies an optional address generation mode for assigning an address in each + delegated prefix. Takes an IPv6 address. When set, the lower bits of the supplied address is + combined with the upper bits of each delegatad prefix received from the WAN interface by the + DHCPv6 Prefix Delegation to form a complete address. When <varname>Assign=</varname> is + disabled, this setting is ignored. When unset, the EUI-64 algorithm will be used to form + addresses. Defaults to unset.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[IPv6AcceptRA] Section Options</title> + <para>The [IPv6AcceptRA] section configures the IPv6 Router Advertisement (RA) client, if it is enabled + with the <varname>IPv6AcceptRA=</varname> setting described above:</para> + + <variablelist class='network-directives'> + <varlistentry> + <term><varname>UseDNS=</varname></term> + <listitem> + <para>When true (the default), the DNS servers received in the Router Advertisement will be used and take + precedence over any statically configured ones.</para> + + <para>This corresponds to the <option>nameserver</option> option in <citerefentry + project='man-pages'><refentrytitle>resolv.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>UseDomains=</varname></term> + <listitem> + <para>Takes a boolean, or the special value <literal>route</literal>. When true, the domain name + received via IPv6 Router Advertisement (RA) will be used as DNS search domain over this link, similar to + the effect of the <option>Domains=</option> setting. If set to <literal>route</literal>, the domain name + received via IPv6 RA will be used for routing DNS queries only, but not for searching, similar to the + effect of the <option>Domains=</option> setting when the argument is prefixed with + <literal>~</literal>. Defaults to false.</para> + + <para>It is recommended to enable this option only on trusted networks, as setting this affects resolution + of all hostnames, in particular of single-label names. It is generally safer to use the supplied domain + only as routing domain, rather than as search domain, in order to not have it affect local resolution of + single-label names.</para> + + <para>When set to true, this setting corresponds to the <option>domain</option> option in <citerefentry + project='man-pages'><refentrytitle>resolv.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>RouteTable=<replaceable>num</replaceable></varname></term> + <listitem> + <para>The table identifier for the routes received in the Router Advertisement + (a number between 1 and 4294967295, or 0 to unset). + The table can be retrieved using <command>ip route show table <replaceable>num</replaceable></command>. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>UseAutonomousPrefix=</varname></term> + <listitem> + <para>When true (the default), the autonomous prefix received in the Router Advertisement will be used and take + precedence over any statically configured ones.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>UseOnLinkPrefix=</varname></term> + <listitem> + <para>When true (the default), the onlink prefix received in the Router Advertisement will be + used and takes precedence over any statically configured ones.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>DenyList=</varname></term> + <listitem> + <para>A whitespace-separated list of IPv6 prefixes. IPv6 prefixes supplied via router advertisements in the list are ignored.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>DHCPv6Client=</varname></term> + <listitem> + <para>Takes a boolean, or the special value <literal>always</literal>. When true or + <literal>always</literal>, the DHCPv6 client will be started when the RA has the managed or + other information flag. If set to <literal>always</literal>, the DHCPv6 client will also be + started in managed mode when neither managed nor other information flag is set in the RA. + Defaults to true.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[DHCPServer] Section Options</title> + <para>The [DHCPServer] section contains settings for the DHCP server, if enabled via the + <varname>DHCPServer=</varname> option described above:</para> + + <variablelist class='network-directives'> + + <varlistentry> + <term><varname>PoolOffset=</varname></term> + <term><varname>PoolSize=</varname></term> + + <listitem><para>Configures the pool of addresses to hand out. The pool + is a contiguous sequence of IP addresses in the subnet configured for + the server address, which does not include the subnet nor the broadcast + address. <varname>PoolOffset=</varname> takes the offset of the pool + from the start of subnet, or zero to use the default value. + <varname>PoolSize=</varname> takes the number of IP addresses in the + pool or zero to use the default value. By default, the pool starts at + the first address after the subnet address and takes up the rest of + the subnet, excluding the broadcast address. If the pool includes + the server address (the default), this is reserved and not handed + out to clients.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>DefaultLeaseTimeSec=</varname></term> + <term><varname>MaxLeaseTimeSec=</varname></term> + + <listitem><para>Control the default and maximum DHCP lease + time to pass to clients. These settings take time values in seconds or + another common time unit, depending on the suffix. The default + lease time is used for clients that did not ask for a specific + lease time. If a client asks for a lease time longer than the + maximum lease time, it is automatically shortened to the + specified time. The default lease time defaults to 1h, the + maximum lease time to 12h. Shorter lease times are beneficial + if the configuration data in DHCP leases changes frequently + and clients shall learn the new settings with shorter + latencies. Longer lease times reduce the generated DHCP + network traffic.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>EmitDNS=</varname></term> + <term><varname>DNS=</varname></term> + + <listitem><para><varname>EmitDNS=</varname> takes a boolean. Configures whether the DHCP leases + handed out to clients shall contain DNS server information. Defaults to <literal>yes</literal>. The + DNS servers to pass to clients may be configured with the <varname>DNS=</varname> option, which takes + a list of IPv4 addresses. If the <varname>EmitDNS=</varname> option is enabled but no servers + configured, the servers are automatically propagated from an "uplink" interface that has appropriate + servers set. The "uplink" interface is determined by the default route of the system with the highest + priority. Note that this information is acquired at the time the lease is handed out, and does not + take uplink interfaces into account that acquire DNS server information at a later point. If no + suitable uplinkg interface is found the DNS server data from <filename>/etc/resolv.conf</filename> is + used. Also, note that the leases are not refreshed if the uplink network configuration changes. To + ensure clients regularly acquire the most current uplink DNS server information, it is thus advisable + to shorten the DHCP lease time via <varname>MaxLeaseTimeSec=</varname> described + above.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>EmitNTP=</varname></term> + <term><varname>NTP=</varname></term> + <term><varname>EmitSIP=</varname></term> + <term><varname>SIP=</varname></term> + <term><varname>EmitPOP3=</varname></term> + <term><varname>POP3=</varname></term> + <term><varname>EmitSMTP=</varname></term> + <term><varname>SMTP=</varname></term> + <term><varname>EmitLPR=</varname></term> + <term><varname>LPR=</varname></term> + + <listitem><para>Similar to the <varname>EmitDNS=</varname> and <varname>DNS=</varname> settings + described above, these settings configure whether and what server information for the indicate + protocol shall be emitted as part of the DHCP lease. The same syntax, propagation semantics and + defaults apply as for <varname>EmitDNS=</varname> and <varname>DNS=</varname>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>EmitRouter=</varname></term> + + <listitem><para>Similar to the <varname>EmitDNS=</varname> + setting described above, this setting configures whether the + DHCP lease should contain the router option. The same syntax, + propagation semantics and defaults apply as for + <varname>EmitDNS=</varname>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>EmitTimezone=</varname></term> + <term><varname>Timezone=</varname></term> + + <listitem><para>Takes a boolean. Configures whether the DHCP leases handed out + to clients shall contain timezone information. Defaults to <literal>yes</literal>. The + <varname>Timezone=</varname> setting takes a timezone string + (such as <literal>Europe/Berlin</literal> or + <literal>UTC</literal>) to pass to clients. If no explicit + timezone is set, the system timezone of the local host is + propagated, as determined by the + <filename>/etc/localtime</filename> symlink.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>SendOption=</varname></term> + <listitem> + <para>Send a raw option with value via DHCPv4 server. Takes a DHCP option number, data type + and data (<literal><replaceable>option</replaceable>:<replaceable>type</replaceable>:<replaceable>value</replaceable></literal>). + The option number is an integer in the range 1..254. The type takes one of <literal>uint8</literal>, + <literal>uint16</literal>, <literal>uint32</literal>, <literal>ipv4address</literal>, <literal>ipv6address</literal>, or + <literal>string</literal>. Special characters in the data string may be escaped using + <ulink url="https://en.wikipedia.org/wiki/Escape_sequences_in_C#Table_of_escape_sequences">C-style + escapes</ulink>. This setting can be specified multiple times. If an empty string is specified, + then all options specified earlier are cleared. Defaults to unset.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>SendVendorOption=</varname></term> + <listitem> + <para>Send a vendor option with value via DHCPv4 server. Takes a DHCP option number, data type + and data (<literal><replaceable>option</replaceable>:<replaceable>type</replaceable>:<replaceable>value</replaceable></literal>). + The option number is an integer in the range 1..254. The type takes one of <literal>uint8</literal>, + <literal>uint16</literal>, <literal>uint32</literal>, <literal>ipv4address</literal>, or + <literal>string</literal>. Special characters in the data string may be escaped using + <ulink url="https://en.wikipedia.org/wiki/Escape_sequences_in_C#Table_of_escape_sequences">C-style + escapes</ulink>. This setting can be specified multiple times. If an empty string is specified, + then all options specified earlier are cleared. Defaults to unset.</para> + </listitem> + </varlistentry> + + </variablelist> + </refsect1> + + <refsect1> + <title>[IPv6SendRA] Section Options</title> + <para>The [IPv6SendRA] section contains settings for sending IPv6 Router Advertisements and whether + to act as a router, if enabled via the <varname>IPv6SendRA=</varname> option described above. IPv6 + network prefixes or routes are defined with one or more [IPv6Prefix] or [IPv6RoutePrefix] sections. + </para> + + <variablelist class='network-directives'> + + <varlistentry> + <term><varname>Managed=</varname></term> + <term><varname>OtherInformation=</varname></term> + + <listitem><para>Takes a boolean. Controls whether a DHCPv6 server is used to acquire IPv6 + addresses on the network link when <varname>Managed=</varname> + is set to <literal>true</literal> or if only additional network + information can be obtained via DHCPv6 for the network link when + <varname>OtherInformation=</varname> is set to + <literal>true</literal>. Both settings default to + <literal>false</literal>, which means that a DHCPv6 server is not being + used.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>RouterLifetimeSec=</varname></term> + + <listitem><para>Takes a timespan. Configures the IPv6 router lifetime in seconds. When set to + 0, the host is not acting as a router. Defaults to 30 minutes.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>RouterPreference=</varname></term> + + <listitem><para>Configures IPv6 router preference if + <varname>RouterLifetimeSec=</varname> is non-zero. Valid values are + <literal>high</literal>, <literal>medium</literal> and + <literal>low</literal>, with <literal>normal</literal> and + <literal>default</literal> added as synonyms for + <literal>medium</literal> just to make configuration easier. See + <ulink url="https://tools.ietf.org/html/rfc4191">RFC 4191</ulink> + for details. Defaults to <literal>medium</literal>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>EmitDNS=</varname></term> + <term><varname>DNS=</varname></term> + + <listitem><para><varname>DNS=</varname> specifies a list of recursive DNS server IPv6 addresses that + are distributed via Router Advertisement messages when <varname>EmitDNS=</varname> is + true. <varname>DNS=</varname> also takes special value <literal>_link_local</literal>; in that case + the IPv6 link local address is distributed. If <varname>DNS=</varname> is empty, DNS servers are read + from the [Network] section. If the [Network] section does not contain any DNS servers either, DNS + servers from the uplink with the highest priority default route are used. When + <varname>EmitDNS=</varname> is false, no DNS server information is sent in Router Advertisement + messages. <varname>EmitDNS=</varname> defaults to true.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>EmitDomains=</varname></term> + <term><varname>Domains=</varname></term> + + <listitem><para>A list of DNS search domains distributed via Router Advertisement messages when + <varname>EmitDomains=</varname> is true. If <varname>Domains=</varname> is empty, DNS search domains + are read from the [Network] section. If the [Network] section does not contain any DNS search domains + either, DNS search domains from the uplink with the highest priority default route are used. When + <varname>EmitDomains=</varname> is false, no DNS search domain information is sent in Router + Advertisement messages. <varname>EmitDomains=</varname> defaults to true.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>DNSLifetimeSec=</varname></term> + + <listitem><para>Lifetime in seconds for the DNS server addresses listed + in <varname>DNS=</varname> and search domains listed in + <varname>Domains=</varname>.</para></listitem> + </varlistentry> + + </variablelist> + </refsect1> + + <refsect1> + <title>[IPv6Prefix] Section Options</title> + <para>One or more [IPv6Prefix] sections contain the IPv6 prefixes that are announced via Router + Advertisements. See <ulink url="https://tools.ietf.org/html/rfc4861">RFC 4861</ulink> for further + details.</para> + + <variablelist class='network-directives'> + + <varlistentry> + <term><varname>AddressAutoconfiguration=</varname></term> + <term><varname>OnLink=</varname></term> + + <listitem><para>Takes a boolean to specify whether IPv6 addresses can be + autoconfigured with this prefix and whether the prefix can be used for + onlink determination. Both settings default to <literal>true</literal> + in order to ease configuration. + </para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>Prefix=</varname></term> + + <listitem><para>The IPv6 prefix that is to be distributed to hosts. Similarly to configuring static + IPv6 addresses, the setting is configured as an IPv6 prefix and its prefix length, separated by a + <literal>/</literal> character. Use multiple [IPv6Prefix] sections to configure multiple IPv6 + prefixes since prefix lifetimes, address autoconfiguration and onlink status may differ from one + prefix to another.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>PreferredLifetimeSec=</varname></term> + <term><varname>ValidLifetimeSec=</varname></term> + + <listitem><para>Preferred and valid lifetimes for the prefix measured in + seconds. <varname>PreferredLifetimeSec=</varname> defaults to 604800 + seconds (one week) and <varname>ValidLifetimeSec=</varname> defaults + to 2592000 seconds (30 days).</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>Assign=</varname></term> + <listitem><para>Takes a boolean. When true, adds an address from the prefix. Default to false. + </para></listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[IPv6RoutePrefix] Section Options</title> + <para>One or more [IPv6RoutePrefix] sections contain the IPv6 + prefix routes that are announced via Router Advertisements. See + <ulink url="https://tools.ietf.org/html/rfc4191">RFC 4191</ulink> + for further details.</para> + + <variablelist class='network-directives'> + + <varlistentry> + <term><varname>Route=</varname></term> + + <listitem><para>The IPv6 route that is to be distributed to hosts. Similarly to configuring static + IPv6 routes, the setting is configured as an IPv6 prefix routes and its prefix route length, + separated by a <literal>/</literal> character. Use multiple [IPv6PrefixRoutes] sections to configure + multiple IPv6 prefix routes.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>LifetimeSec=</varname></term> + + <listitem><para>Lifetime for the route prefix measured in + seconds. <varname>LifetimeSec=</varname> defaults to 604800 seconds (one week). + </para></listitem> + </varlistentry> + + </variablelist> + </refsect1> + + <refsect1> + <title>[Bridge] Section Options</title> + <para>The [Bridge] section accepts the following keys:</para> + <variablelist class='network-directives'> + <varlistentry> + <term><varname>UnicastFlood=</varname></term> + <listitem> + <para>Takes a boolean. Controls whether the bridge should flood + traffic for which an FDB entry is missing and the destination + is unknown through this port. When unset, the kernel's default will be used. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>MulticastFlood=</varname></term> + <listitem> + <para>Takes a boolean. Controls whether the bridge should flood + traffic for which an MDB entry is missing and the destination + is unknown through this port. When unset, the kernel's default will be used. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>MulticastToUnicast=</varname></term> + <listitem> + <para>Takes a boolean. Multicast to unicast works on top of the multicast snooping feature of + the bridge. Which means unicast copies are only delivered to hosts which are interested in it. + When unset, the kernel's default will be used. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>NeighborSuppression=</varname></term> + <listitem> + <para>Takes a boolean. Configures whether ARP and ND neighbor suppression is enabled for + this port. When unset, the kernel's default will be used. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Learning=</varname></term> + <listitem> + <para>Takes a boolean. Configures whether MAC address learning is enabled for + this port. When unset, the kernel's default will be used. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>HairPin=</varname></term> + <listitem> + <para>Takes a boolean. Configures whether traffic may be sent back out of the port on which it + was received. When this flag is false, then the bridge will not forward traffic back out of the + receiving port. When unset, the kernel's default will be used.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>UseBPDU=</varname></term> + <listitem> + <para>Takes a boolean. Configures whether STP Bridge Protocol Data Units will be + processed by the bridge port. When unset, the kernel's default will be used.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>FastLeave=</varname></term> + <listitem> + <para>Takes a boolean. This flag allows the bridge to immediately stop multicast + traffic on a port that receives an IGMP Leave message. It is only used with + IGMP snooping if enabled on the bridge. When unset, the kernel's default will be used.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>AllowPortToBeRoot=</varname></term> + <listitem> + <para>Takes a boolean. Configures whether a given port is allowed to + become a root port. Only used when STP is enabled on the bridge. + When unset, the kernel's default will be used.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>ProxyARP=</varname></term> + <listitem> + <para>Takes a boolean. Configures whether proxy ARP to be enabled on this port. + When unset, the kernel's default will be used.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>ProxyARPWiFi=</varname></term> + <listitem> + <para>Takes a boolean. Configures whether proxy ARP to be enabled on this port + which meets extended requirements by IEEE 802.11 and Hotspot 2.0 specifications. + When unset, the kernel's default will be used.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>MulticastRouter=</varname></term> + <listitem> + <para>Configures this port for having multicast routers attached. A port with a multicast + router will receive all multicast traffic. Takes one of <literal>no</literal> + to disable multicast routers on this port, <literal>query</literal> to let the system detect + the presence of routers, <literal>permanent</literal> to permanently enable multicast traffic + forwarding on this port, or <literal>temporary</literal> to enable multicast routers temporarily + on this port, not depending on incoming queries. When unset, the kernel's default will be used.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Cost=</varname></term> + <listitem> + <para>Sets the "cost" of sending packets of this interface. + Each port in a bridge may have a different speed and the cost + is used to decide which link to use. Faster interfaces + should have lower costs. It is an integer value between 1 and + 65535.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Priority=</varname></term> + <listitem> + <para>Sets the "priority" of sending packets on this interface. + Each port in a bridge may have a different priority which is used + to decide which link to use. Lower value means higher priority. + It is an integer value between 0 to 63. Networkd does not set any + default, meaning the kernel default value of 32 is used.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + <refsect1> + <title>[BridgeFDB] Section Options</title> + <para>The [BridgeFDB] section manages the forwarding database table of a port and accepts the following + keys. Specify several [BridgeFDB] sections to configure several static MAC table entries.</para> + + <variablelist class='network-directives'> + <varlistentry> + <term><varname>MACAddress=</varname></term> + <listitem> + <para>As in the [Network] section. This key is mandatory.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Destination=</varname></term> + <listitem> + <para>Takes an IP address of the destination VXLAN tunnel endpoint.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>VLANId=</varname></term> + <listitem> + <para>The VLAN ID for the new static MAC table entry. If + omitted, no VLAN ID information is appended to the new static MAC + table entry.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>VNI=</varname></term> + <listitem> + <para>The VXLAN Network Identifier (or VXLAN Segment ID) to use to connect to + the remote VXLAN tunnel endpoint. Takes a number in the range 1-16777215. + Defaults to unset.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>AssociatedWith=</varname></term> + <listitem> + <para>Specifies where the address is associated with. Takes one of <literal>use</literal>, + <literal>self</literal>, <literal>master</literal> or <literal>router</literal>. + <literal>use</literal> means the address is in use. User space can use this option to + indicate to the kernel that the fdb entry is in use. <literal>self</literal> means + the address is associated with the port drivers fdb. Usually hardware. <literal>master</literal> + means the address is associated with master devices fdb. <literal>router</literal> means + the destination address is associated with a router. Note that it's valid if the referenced + device is a VXLAN type device and has route shortcircuit enabled. Defaults to <literal>self</literal>.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + <refsect1> + <title>[BridgeMDB] Section Options</title> + <para>The [BridgeMDB] section manages the multicast membership entries forwarding database table of a port and accepts the following + keys. Specify several [BridgeMDB] sections to configure several permanent multicast membership entries.</para> + + <variablelist class='network-directives'> + <varlistentry> + <term><varname>MulticastGroupAddress=</varname></term> + <listitem> + <para>Specifies the IPv4 or IPv6 multicast group address to add. This setting is mandatory.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>VLANId=</varname></term> + <listitem> + <para>The VLAN ID for the new entry. Valid ranges are 0 (no VLAN) to 4094. Optional, defaults to 0.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[LLDP] Section Options</title> + <para>The [LLDP] section manages the Link Layer Discovery Protocol (LLDP) and accepts the following + keys:</para> + <variablelist class='network-directives'> + <varlistentry> + <term><varname>MUDURL=</varname></term> + <listitem> + <para>When configured, the specified Manufacturer Usage Descriptions (MUD) URL will be sent in + LLDP packets. The syntax and semantics are the same as for <varname>MUDURL=</varname> in the + [DHCPv4] section described above.</para> + + <para>The MUD URLs received via LLDP packets are saved and can be read using the + <function>sd_lldp_neighbor_get_mud_url()</function> function.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[CAN] Section Options</title> + <para>The [CAN] section manages the Controller Area Network (CAN bus) and accepts the + following keys:</para> + <variablelist class='network-directives'> + <varlistentry> + <term><varname>BitRate=</varname></term> + <listitem> + <para>The bitrate of CAN device in bits per second. The usual SI prefixes (K, M) with the base of 1000 can + be used here. Takes a number in the range 1..4294967295.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>SamplePoint=</varname></term> + <listitem> + <para>Optional sample point in percent with one decimal (e.g. <literal>75%</literal>, + <literal>87.5%</literal>) or permille (e.g. <literal>875‰</literal>).</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>DataBitRate=</varname></term> + <term><varname>DataSamplePoint=</varname></term> + <listitem> + <para>The bitrate and sample point for the data phase, if CAN-FD is used. These settings are + analogous to the <varname>BitRate=</varname> and <varname>SamplePoint=</varname> keys.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>FDMode=</varname></term> + <listitem> + <para>Takes a boolean. When <literal>yes</literal>, CAN-FD mode is enabled for the interface. + Note, that a bitrate and optional sample point should also be set for the CAN-FD data phase using + the <varname>DataBitRate=</varname> and <varname>DataSamplePoint=</varname> keys.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>FDNonISO=</varname></term> + <listitem> + <para>Takes a boolean. When <literal>yes</literal>, non-ISO CAN-FD mode is enabled for the + interface. When unset, the kernel's default will be used.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>RestartSec=</varname></term> + <listitem> + <para>Automatic restart delay time. If set to a non-zero value, a restart of the CAN controller will be + triggered automatically in case of a bus-off condition after the specified delay time. Subsecond delays can + be specified using decimals (e.g. <literal>0.1s</literal>) or a <literal>ms</literal> or + <literal>us</literal> postfix. Using <literal>infinity</literal> or <literal>0</literal> will turn the + automatic restart off. By default automatic restart is disabled.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>Termination=</varname></term> + <listitem> + <para>Takes a boolean. When <literal>yes</literal>, the termination resistor will be selected for + the bias network. When unset, the kernel's default will be used.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>TripleSampling=</varname></term> + <listitem> + <para>Takes a boolean. When <literal>yes</literal>, three samples (instead of one) are used to determine + the value of a received bit by majority rule. When unset, the kernel's default will be used.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>ListenOnly=</varname></term> + <listitem> + <para>Takes a boolean. When <literal>yes</literal>, listen-only mode is enabled. When the + interface is in listen-only mode, the interface neither transmit CAN frames nor send ACK + bit. Listen-only mode is important to debug CAN networks without interfering with the + communication or acknowledge the CAN frame. When unset, the kernel's default will be used. + </para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[QDisc] Section Options</title> + <para>The [QDisc] section manages the traffic control queueing discipline (qdisc).</para> + + <variablelist class='network-directives'> + <varlistentry> + <term><varname>Parent=</varname></term> + <listitem> + <para>Specifies the parent Queueing Discipline (qdisc). Takes one of <literal>clsact</literal> + or <literal>ingress</literal>. This is mandatory.</para> + </listitem> + </varlistentry> + + <xi:include href="tc.xml" xpointer="qdisc-handle" /> + </variablelist> + </refsect1> + + <refsect1> + <title>[NetworkEmulator] Section Options</title> + <para>The [NetworkEmulator] section manages the queueing discipline (qdisc) of the network emulator. It + can be used to configure the kernel packet scheduler and simulate packet delay and loss for UDP or TCP + applications, or limit the bandwidth usage of a particular service to simulate internet connections. + </para> + + <variablelist class='network-directives'> + <xi:include href="tc.xml" xpointer="qdisc-parent" /> + <xi:include href="tc.xml" xpointer="qdisc-handle" /> + + <varlistentry> + <term><varname>DelaySec=</varname></term> + <listitem> + <para>Specifies the fixed amount of delay to be added to all packets going out of the + interface. Defaults to unset.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>DelayJitterSec=</varname></term> + <listitem> + <para>Specifies the chosen delay to be added to the packets outgoing to the network + interface. Defaults to unset.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>PacketLimit=</varname></term> + <listitem> + <para>Specifies the maximum number of packets the qdisc may hold queued at a time. + An unsigned integer in the range 0–4294967294. Defaults to 1000.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>LossRate=</varname></term> + <listitem> + <para>Specifies an independent loss probability to be added to the packets outgoing from the + network interface. Takes a percentage value, suffixed with "%". Defaults to unset.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>DuplicateRate=</varname></term> + <listitem> + <para>Specifies that the chosen percent of packets is duplicated before queuing them. + Takes a percentage value, suffixed with "%". Defaults to unset.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[TokenBucketFilter] Section Options</title> + <para>The [TokenBucketFilter] section manages the queueing discipline (qdisc) of token bucket filter + (tbf).</para> + + <variablelist class='network-directives'> + <xi:include href="tc.xml" xpointer="qdisc-parent" /> + <xi:include href="tc.xml" xpointer="qdisc-handle" /> + + <varlistentry> + <term><varname>LatencySec=</varname></term> + <listitem> + <para>Specifies the latency parameter, which specifies the maximum amount of time a + packet can sit in the Token Bucket Filter (TBF). Defaults to unset.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>LimitBytes=</varname></term> + <listitem> + <para>Takes the number of bytes that can be queued waiting for tokens to become available. + When the size is suffixed with K, M, or G, it is parsed as Kilobytes, Megabytes, or Gigabytes, + respectively, to the base of 1024. Defaults to unset.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>BurstBytes=</varname></term> + <listitem> + <para>Specifies the size of the bucket. This is the maximum amount of bytes that tokens + can be available for instantaneous transfer. When the size is suffixed with K, M, or G, it is + parsed as Kilobytes, Megabytes, or Gigabytes, respectively, to the base of 1024. Defaults to + unset.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>Rate=</varname></term> + <listitem> + <para>Specifies the device specific bandwidth. When suffixed with K, M, or G, the specified + bandwidth is parsed as Kilobits, Megabits, or Gigabits, respectively, to the base of 1000. + Defaults to unset.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>MPUBytes=</varname></term> + <listitem> + <para>The Minimum Packet Unit (MPU) determines the minimal token usage (specified in bytes) + for a packet. When suffixed with K, M, or G, the specified size is parsed as Kilobytes, + Megabytes, or Gigabytes, respectively, to the base of 1024. Defaults to zero.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>PeakRate=</varname></term> + <listitem> + <para>Takes the maximum depletion rate of the bucket. When suffixed with K, M, or G, the + specified size is parsed as Kilobits, Megabits, or Gigabits, respectively, to the base of + 1000. Defaults to unset.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>MTUBytes=</varname></term> + <listitem> + <para>Specifies the size of the peakrate bucket. When suffixed with K, M, or G, the specified + size is parsed as Kilobytes, Megabytes, or Gigabytes, respectively, to the base of 1024. + Defaults to unset.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[PIE] Section Options</title> + <para>The [PIE] section manages the queueing discipline (qdisc) of Proportional Integral + controller-Enhanced (PIE).</para> + + <variablelist class='network-directives'> + <xi:include href="tc.xml" xpointer="qdisc-parent" /> + <xi:include href="tc.xml" xpointer="qdisc-handle" /> + + <varlistentry> + <term><varname>PacketLimit=</varname></term> + <listitem> + <para>Specifies the hard limit on the queue size in number of packets. When this limit is reached, incoming packets are + dropped. An unsigned integer in the range 1–4294967294. Defaults to unset and kernel's default is used.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[FlowQueuePIE] Section Options</title> + <para>The <literal>[FlowQueuePIE]</literal> section manages the queueing discipline + (qdisc) of Flow Queue Proportional Integral controller-Enhanced (fq_pie).</para> + + <variablelist class='network-directives'> + <xi:include href="tc.xml" xpointer="qdisc-parent" /> + <xi:include href="tc.xml" xpointer="qdisc-handle" /> + + <varlistentry> + <term><varname>PacketLimit=</varname></term> + <listitem> + <para>Specifies the hard limit on the queue size in number of packets. When this limit is reached, incoming packets are + dropped. An unsigned integer ranges 1 to 4294967294. Defaults to unset and kernel's default is used.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[StochasticFairBlue] Section Options</title> + <para>The [StochasticFairBlue] section manages the queueing discipline (qdisc) of stochastic fair blue + (sfb).</para> + + <variablelist class='network-directives'> + <xi:include href="tc.xml" xpointer="qdisc-parent" /> + <xi:include href="tc.xml" xpointer="qdisc-handle" /> + + <varlistentry> + <term><varname>PacketLimit=</varname></term> + <listitem> + <para>Specifies the hard limit on the queue size in number of packets. When this limit is reached, + incoming packets are dropped. An unsigned integer in the range 0–4294967294. Defaults to unset and + kernel's default is used.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[StochasticFairnessQueueing] Section Options</title> + <para>The [StochasticFairnessQueueing] section manages the queueing discipline (qdisc) of stochastic + fairness queueing (sfq).</para> + + <variablelist class='network-directives'> + <xi:include href="tc.xml" xpointer="qdisc-parent" /> + <xi:include href="tc.xml" xpointer="qdisc-handle" /> + + <varlistentry> + <term><varname>PerturbPeriodSec=</varname></term> + <listitem> + <para>Specifies the interval in seconds for queue algorithm perturbation. Defaults to unset.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[BFIFO] Section Options</title> + <para>The [BFIFO] section manages the queueing discipline (qdisc) of Byte limited Packet First In First + Out (bfifo).</para> + + <variablelist class='network-directives'> + <xi:include href="tc.xml" xpointer="qdisc-parent" /> + <xi:include href="tc.xml" xpointer="qdisc-handle" /> + + <varlistentry> + <term><varname>LimitBytes=</varname></term> + <listitem> + <para>Specifies the hard limit in bytes on the FIFO buffer size. The size limit prevents overflow + in case the kernel is unable to dequeue packets as quickly as it receives them. When this limit is + reached, incoming packets are dropped. When suffixed with K, M, or G, the specified size is parsed + as Kilobytes, Megabytes, or Gigabytes, respectively, to the base of 1024. Defaults to unset and + kernel default is used.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[PFIFO] Section Options</title> + <para>The [PFIFO] section manages the queueing discipline (qdisc) of Packet First In First Out + (pfifo).</para> + + <variablelist class='network-directives'> + <xi:include href="tc.xml" xpointer="qdisc-parent" /> + <xi:include href="tc.xml" xpointer="qdisc-handle" /> + + <varlistentry> + <term><varname>PacketLimit=</varname></term> + <listitem> + <para>Specifies the hard limit on the FIFO size in number of packets. The size limit (a buffer + size) to prevent it from overflowing in case it is unable to dequeue packets as quickly as it + receives them. When this limit is reached, incoming packets are dropped. An unsigned integer in the + range 0–4294967294. Defaults to unset and kernel's default is used.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[PFIFOHeadDrop] Section Options</title> + <para>The [PFIFOHeadDrop] section manages the queueing discipline (qdisc) of Packet First In First Out + Head Drop (pfifo_head_drop).</para> + + <variablelist class='network-directives'> + <xi:include href="tc.xml" xpointer="qdisc-parent" /> + <xi:include href="tc.xml" xpointer="qdisc-handle" /> + + <varlistentry> + <term><varname>PacketLimit=</varname></term> + <listitem> + <para>As in [PFIFO] section.</para></listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[PFIFOFast] Section Options</title> + <para>The [PFIFOFast] section manages the queueing discipline (qdisc) of Packet First In First Out Fast + (pfifo_fast).</para> + + <variablelist class='network-directives'> + <xi:include href="tc.xml" xpointer="qdisc-parent" /> + <xi:include href="tc.xml" xpointer="qdisc-handle" /> + </variablelist> + </refsect1> + + <refsect1> + <title>[CAKE] Section Options</title> + <para>The [CAKE] section manages the queueing discipline (qdisc) of Common Applications Kept Enhanced + (CAKE).</para> + + <variablelist class='network-directives'> + <xi:include href="tc.xml" xpointer="qdisc-parent" /> + <xi:include href="tc.xml" xpointer="qdisc-handle" /> + + <varlistentry> + <term><varname>OverheadBytes=</varname></term> + <listitem> + <para>Specifies that bytes to be addeded to the size of each packet. Bytes may be negative. Takes + an integer in the range from -64 to 256. Defaults to unset and kernel's default is used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>Bandwidth=</varname></term> + <listitem> + <para>Specifies the shaper bandwidth. When suffixed with K, M, or G, the specified size is + parsed as Kilobits, Megabits, or Gigabits, respectively, to the base of 1000. Defaults to + unset and kernel's default is used.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[ControlledDelay] Section Options</title> + <para>The [ControlledDelay] section manages the queueing discipline (qdisc) of + controlled delay (CoDel).</para> + + <variablelist class='network-directives'> + <xi:include href="tc.xml" xpointer="qdisc-parent" /> + <xi:include href="tc.xml" xpointer="qdisc-handle" /> + + <varlistentry> + <term><varname>PacketLimit=</varname></term> + <listitem> + <para>Specifies the hard limit on the queue size in number of packets. When this limit is reached, + incoming packets are dropped. An unsigned integer in the range 0–4294967294. Defaults to unset and + kernel's default is used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>TargetSec=</varname></term> + <listitem> + <para>Takes a timespan. Specifies the acceptable minimum standing/persistent queue delay. + Defaults to unset and kernel's default is used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>IntervalSec=</varname></term> + <listitem> + <para>Takes a timespan. This is used to ensure that the measured minimum delay does not + become too stale. Defaults to unset and kernel's default is used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>ECN=</varname></term> + <listitem> + <para>Takes a boolean. This can be used to mark packets instead of dropping them. Defaults to + unset and kernel's default is used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>CEThresholdSec=</varname></term> + <listitem> + <para>Takes a timespan. This sets a threshold above which all packets are marked with ECN + Congestion Experienced (CE). Defaults to unset and kernel's default is used.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[DeficitRoundRobinScheduler] Section Options</title> + <para>The [DeficitRoundRobinScheduler] section manages the queueing discipline (qdisc) of Deficit Round + Robin Scheduler (DRR).</para> + + <variablelist class='network-directives'> + <xi:include href="tc.xml" xpointer="qdisc-parent" /> + <xi:include href="tc.xml" xpointer="qdisc-handle" /> + </variablelist> + </refsect1> + + <refsect1> + <title>[DeficitRoundRobinSchedulerClass] Section Options</title> + <para>The [DeficitRoundRobinSchedulerClass] section manages the traffic control class of Deficit Round + Robin Scheduler (DRR).</para> + + <variablelist class='network-directives'> + <xi:include href="tc.xml" xpointer="tclass-parent" /> + <xi:include href="tc.xml" xpointer="tclass-classid" /> + + <varlistentry> + <term><varname>QuantumBytes=</varname></term> + <listitem> + <para>Specifies the amount of bytes a flow is allowed to dequeue before the scheduler moves + to the next class. When suffixed with K, M, or G, the specified size is parsed as Kilobytes, + Megabytes, or Gigabytes, respectively, to the base of 1024. Defaults to the MTU of the + interface.</para> + </listitem> + </varlistentry> + + </variablelist> + </refsect1> + + <refsect1> + <title>[EnhancedTransmissionSelection] Section Options</title> + <para>The [EnhancedTransmissionSelection] section manages the queueing discipline (qdisc) of Enhanced + Transmission Selection (ETS).</para> + + <variablelist class='network-directives'> + <xi:include href="tc.xml" xpointer="qdisc-parent" /> + <xi:include href="tc.xml" xpointer="qdisc-handle" /> + + <varlistentry> + <term><varname>Bands=</varname></term> + <listitem> + <para>Specifies the number of bands. An unsigned integer in the range 1–16. This value has to be at + least large enough to cover the strict bands specified through the <varname>StrictBands=</varname> + and bandwidth-sharing bands specified in <varname>QuantumBytes=</varname>.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>StrictBands=</varname></term> + <listitem> + <para>Specifies the number of bands that should be created in strict mode. An unsigned integer in + the range 1–16.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>QuantumBytes=</varname></term> + <listitem> + <para>Specifies the white-space separated list of quantum used in band-sharing bands. When + suffixed with K, M, or G, the specified size is parsed as Kilobytes, Megabytes, or Gigabytes, + respectively, to the base of 1024. This setting can be specified multiple times. If an empty + string is assigned, then the all previous assignments are cleared.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>PriorityMap=</varname></term> + <listitem> + <para>The priority map maps the priority of a packet to a band. The argument is a whitespace + separated list of numbers. The first number indicates which band the packets with priority 0 should + be put to, the second is for priority 1, and so on. There can be up to 16 numbers in the list. If + there are fewer, the default band that traffic with one of the unmentioned priorities goes to is + the last one. Each band number must be in the range 0..255. This setting can be specified multiple + times. If an empty string is assigned, then the all previous assignments are cleared.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[GenericRandomEarlyDetection] Section Options</title> + <para>The [GenericRandomEarlyDetection] section manages the queueing discipline (qdisc) of Generic Random + Early Detection (GRED).</para> + + <variablelist class='network-directives'> + <xi:include href="tc.xml" xpointer="qdisc-parent" /> + <xi:include href="tc.xml" xpointer="qdisc-handle" /> + + <varlistentry> + <term><varname>VirtualQueues=</varname></term> + <listitem> + <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> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>DefaultVirtualQueue=</varname></term> + <listitem> + <para>Specifies the number of default virtual queue. This must be less than <varname>VirtualQueue=</varname>. + Defaults to unset and kernel's default is used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>GenericRIO=</varname></term> + <listitem> + <para>Takes a boolean. It turns on the RIO-like buffering scheme. Defaults to + unset and kernel's default is used.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[FairQueueingControlledDelay] Section Options</title> + <para>The [FairQueueingControlledDelay] section manages the queueing discipline (qdisc) of fair queuing + controlled delay (FQ-CoDel).</para> + + <variablelist class='network-directives'> + <xi:include href="tc.xml" xpointer="qdisc-parent" /> + <xi:include href="tc.xml" xpointer="qdisc-handle" /> + + <varlistentry> + <term><varname>PacketLimit=</varname></term> + <listitem> + <para>Specifies the hard limit on the real queue size. When this limit is reached, incoming packets are + dropped. Defaults to unset and kernel's default is used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>MemoryLimitBytes=</varname></term> + <listitem> + <para>Specifies the limit on the total number of bytes that can be queued in this FQ-CoDel instance. + When suffixed with K, M, or G, the specified size is parsed as Kilobytes, Megabytes, or Gigabytes, + respectively, to the base of 1024. Defaults to unset and kernel's default is used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>Flows=</varname></term> + <listitem> + <para>Specifies the number of flows into which the incoming packets are classified. + Defaults to unset and kernel's default is used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>TargetSec=</varname></term> + <listitem> + <para>Takes a timespan. Specifies the acceptable minimum standing/persistent queue delay. + Defaults to unset and kernel's default is used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>IntervalSec=</varname></term> + <listitem> + <para>Takes a timespan. This is used to ensure that the measured minimum delay does not + become too stale. Defaults to unset and kernel's default is used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>QuantumBytes=</varname></term> + <listitem> + <para>Specifies the number of bytes used as the "deficit" in the fair queuing algorithm timespan. + When suffixed with K, M, or G, the specified size is parsed as Kilobytes, Megabytes, or Gigabytes, + respectively, to the base of 1024. Defaults to unset and kernel's default is used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>ECN=</varname></term> + <listitem> + <para>Takes a boolean. This can be used to mark packets instead of dropping them. Defaults to + unset and kernel's default is used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>CEThresholdSec=</varname></term> + <listitem> + <para>Takes a timespan. This sets a threshold above which all packets are marked with ECN + Congestion Experienced (CE). Defaults to unset and kernel's default is used.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[FairQueueing] Section Options</title> + <para>The [FairQueueing] section manages the queueing discipline (qdisc) of fair queue traffic policing + (FQ).</para> + + <variablelist class='network-directives'> + <xi:include href="tc.xml" xpointer="qdisc-parent" /> + <xi:include href="tc.xml" xpointer="qdisc-handle" /> + + <varlistentry> + <term><varname>PacketLimit=</varname></term> + <listitem> + <para>Specifies the hard limit on the real queue size. When this limit is reached, incoming packets are + dropped. Defaults to unset and kernel's default is used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>FlowLimit=</varname></term> + <listitem> + <para>Specifies the hard limit on the maximum number of packets queued per flow. Defaults to + unset and kernel's default is used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>QuantumBytes=</varname></term> + <listitem> + <para>Specifies the credit per dequeue RR round, i.e. the amount of bytes a flow is allowed + to dequeue at once. When suffixed with K, M, or G, the specified size is parsed as Kilobytes, + Megabytes, or Gigabytes, respectively, to the base of 1024. Defaults to unset and kernel's + default is used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>InitialQuantumBytes=</varname></term> + <listitem> + <para>Specifies the initial sending rate credit, i.e. the amount of bytes a new flow is + allowed to dequeue initially. When suffixed with K, M, or G, the specified size is parsed as + Kilobytes, Megabytes, or Gigabytes, respectively, to the base of 1024. Defaults to unset and + kernel's default is used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>MaximumRate=</varname></term> + <listitem> + <para>Specifies the maximum sending rate of a flow. When suffixed with K, M, or G, the + specified size is parsed as Kilobits, Megabits, or Gigabits, respectively, to the base of + 1000. Defaults to unset and kernel's default is used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>Buckets=</varname></term> + <listitem> + <para>Specifies the size of the hash table used for flow lookups. Defaults to unset and + kernel's default is used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>OrphanMask=</varname></term> + <listitem> + <para>Takes an unsigned integer. For packets not owned by a socket, fq is able to mask a part + of hash and reduce number of buckets associated with the traffic. Defaults to unset and + kernel's default is used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>Pacing=</varname></term> + <listitem> + <para>Takes a boolean, and enables or disables flow pacing. Defaults to unset and kernel's + default is used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>CEThresholdSec=</varname></term> + <listitem> + <para>Takes a timespan. This sets a threshold above which all packets are marked with ECN + Congestion Experienced (CE). Defaults to unset and kernel's default is used.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[TrivialLinkEqualizer] Section Options</title> + <para>The [TrivialLinkEqualizer] section manages the queueing discipline (qdisc) of trivial link + equalizer (teql).</para> + + <variablelist class='network-directives'> + <xi:include href="tc.xml" xpointer="qdisc-parent" /> + <xi:include href="tc.xml" xpointer="qdisc-handle" /> + + <varlistentry> + <term><varname>Id=</varname></term> + <listitem> + <para>Specifies the interface ID <literal>N</literal> of teql. Defaults to <literal>0</literal>. + Note that when teql is used, currently, the module <constant>sch_teql</constant> with + <constant>max_equalizers=N+1</constant> option must be loaded before + <command>systemd-networkd</command> is started.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[HierarchyTokenBucket] Section Options</title> + <para>The [HierarchyTokenBucket] section manages the queueing discipline (qdisc) of hierarchy token + bucket (htb).</para> + + <variablelist class='network-directives'> + <xi:include href="tc.xml" xpointer="qdisc-parent" /> + <xi:include href="tc.xml" xpointer="qdisc-handle" /> + + <varlistentry> + <term><varname>DefaultClass=</varname></term> + <listitem> + <para>Takes the minor id in hexadecimal of the default class. Unclassified traffic gets sent + to the class. Defaults to unset.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>RateToQuantum=</varname></term> + <listitem> + <para>Takes an unsigned integer. The DRR quantums are calculated by dividing the value + configured in <varname>Rate=</varname> by <varname>RateToQuantum=</varname>.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[HierarchyTokenBucketClass] Section Options</title> + <para>The [HierarchyTokenBucketClass] section manages the traffic control class of hierarchy token bucket + (htb).</para> + + <variablelist class='network-directives'> + <xi:include href="tc.xml" xpointer="tclass-parent" /> + <xi:include href="tc.xml" xpointer="tclass-classid" /> + + <varlistentry> + <term><varname>Priority=</varname></term> + <listitem> + <para>Specifies the priority of the class. In the round-robin process, classes with the lowest + priority field are tried for packets first.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>QuantumBytes=</varname></term> + <listitem> + <para>Specifies how many bytes to serve from leaf at once. When suffixed with K, M, or G, the + specified size is parsed as Kilobytes, Megabytes, or Gigabytes, respectively, to the base of + 1024.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>MTUBytes=</varname></term> + <listitem> + <para>Specifies the maximum packet size we create. When suffixed with K, M, or G, the specified + size is parsed as Kilobytes, Megabytes, or Gigabytes, respectively, to the base of 1024.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>OverheadBytes=</varname></term> + <listitem> + <para>Takes an unsigned integer which specifies per-packet size overhead used in rate + computations. When suffixed with K, M, or G, the specified size is parsed as Kilobytes, + Megabytes, or Gigabytes, respectively, to the base of 1024.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>Rate=</varname></term> + <listitem> + <para>Specifies the maximum rate this class and all its children are guaranteed. When suffixed + with K, M, or G, the specified size is parsed as Kilobits, Megabits, or Gigabits, respectively, + to the base of 1000. This setting is mandatory.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>CeilRate=</varname></term> + <listitem> + <para>Specifies the maximum rate at which a class can send, if its parent has bandwidth to spare. + When suffixed with K, M, or G, the specified size is parsed as Kilobits, Megabits, or Gigabits, + respectively, to the base of 1000. When unset, the value specified with <varname>Rate=</varname> + is used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>BufferBytes=</varname></term> + <listitem> + <para>Specifies the maximum bytes burst which can be accumulated during idle period. When suffixed + with K, M, or G, the specified size is parsed as Kilobytes, Megabytes, or Gigabytes, respectively, + to the base of 1024.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>CeilBufferBytes=</varname></term> + <listitem> + <para>Specifies the maximum bytes burst for ceil which can be accumulated during idle period. + When suffixed with K, M, or G, the specified size is parsed as Kilobytes, Megabytes, or Gigabytes, + respectively, to the base of 1024.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[HeavyHitterFilter] Section Options</title> + <para>The [HeavyHitterFilter] section manages the queueing discipline (qdisc) of Heavy Hitter Filter + (hhf).</para> + + <variablelist class='network-directives'> + <xi:include href="tc.xml" xpointer="qdisc-parent" /> + <xi:include href="tc.xml" xpointer="qdisc-handle" /> + + <varlistentry> + <term><varname>PacketLimit=</varname></term> + <listitem> + <para>Specifies the hard limit on the queue size in number of packets. When this limit is reached, + incoming packets are dropped. An unsigned integer in the range 0–4294967294. Defaults to unset and + kernel's default is used.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[QuickFairQueueing] Section Options</title> + <para>The [QuickFairQueueing] section manages the queueing discipline (qdisc) of Quick Fair Queueing + (QFQ).</para> + + <variablelist class='network-directives'> + <xi:include href="tc.xml" xpointer="qdisc-parent" /> + <xi:include href="tc.xml" xpointer="qdisc-handle" /> + </variablelist> + </refsect1> + + <refsect1> + <title>[QuickFairQueueingClass] Section Options</title> + <para>The [QuickFairQueueingClass] section manages the traffic control class of Quick Fair Queueing + (qfq).</para> + + <variablelist class='network-directives'> + <xi:include href="tc.xml" xpointer="tclass-parent" /> + <xi:include href="tc.xml" xpointer="tclass-classid" /> + + <varlistentry> + <term><varname>Weight=</varname></term> + <listitem> + <para>Specifies the weight of the class. Takes an integer in the range 1..1023. Defaults to + unset in which case the kernel default is used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>MaxPacketBytes=</varname></term> + <listitem> + <para>Specifies the maximum packet size in bytes for the class. When suffixed with K, M, or G, the specified + size is parsed as Kilobytes, Megabytes, or Gigabytes, respectively, to the base of 1024. When unset, + the kernel default is used.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>[BridgeVLAN] Section Options</title> + <para>The [BridgeVLAN] section manages the VLAN ID configuration of a bridge port and accepts the + following keys. Specify several [BridgeVLAN] sections to configure several VLAN entries. The + <varname>VLANFiltering=</varname> option has to be enabled, see the [Bridge] section in + <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para> + + <variablelist class='network-directives'> + <varlistentry> + <term><varname>VLAN=</varname></term> + <listitem> + <para>The VLAN ID allowed on the port. This can be either a single ID or a range M-N. VLAN IDs are valid + from 1 to 4094.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>EgressUntagged=</varname></term> + <listitem> + <para>The VLAN ID specified here will be used to untag frames on egress. Configuring + <varname>EgressUntagged=</varname> implicates the use of <varname>VLAN=</varname> above and will enable the + VLAN ID for ingress as well. This can be either a single ID or a range M-N.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><varname>PVID=</varname></term> + <listitem> + <para>The Port VLAN ID specified here is assigned to all untagged frames at ingress. + <varname>PVID=</varname> can be used only once. Configuring <varname>PVID=</varname> implicates the use of + <varname>VLAN=</varname> above and will enable the VLAN ID for ingress as well.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>Examples</title> + <example> + <title>Static network configuration</title> + + <programlisting># /etc/systemd/network/50-static.network +[Match] +Name=enp2s0 + +[Network] +Address=192.168.0.15/24 +Gateway=192.168.0.1</programlisting> + + <para>This brings interface <literal>enp2s0</literal> up with a static address. The + specified gateway will be used for a default route.</para> + </example> + + <example> + <title>DHCP on ethernet links</title> + + <programlisting># /etc/systemd/network/80-dhcp.network +[Match] +Name=en* + +[Network] +DHCP=yes</programlisting> + + <para>This will enable DHCPv4 and DHCPv6 on all interfaces with names starting with + <literal>en</literal> (i.e. ethernet interfaces).</para> + </example> + + <example> + <title>IPv6 Prefix Delegation</title> + + <programlisting># /etc/systemd/network/55-ipv6-pd-upstream.network +[Match] +Name=enp1s0 + +[Network] +DHCP=ipv6</programlisting> + + <programlisting># /etc/systemd/network/56-ipv6-pd-downstream.network +[Match] +Name=enp2s0 + +[Network] +IPv6SendRA=yes +DHCPv6PrefixDelegation=yes</programlisting> + + <para>This will enable DHCPv6-PD on the interface enp1s0 as an upstream interface where the + DHCPv6 client is running and enp2s0 as a downstream interface where the prefix is delegated to. + The delegated prefixes are distributed by IPv6 Router Advertisement on the downstream network. + </para> + </example> + + <example> + <title>A bridge with two enslaved links</title> + + <programlisting># /etc/systemd/network/25-bridge-static.network +[Match] +Name=bridge0 + +[Network] +Address=192.168.0.15/24 +Gateway=192.168.0.1 +DNS=192.168.0.1</programlisting> + + <programlisting># /etc/systemd/network/25-bridge-slave-interface-1.network +[Match] +Name=enp2s0 + +[Network] +Bridge=bridge0</programlisting> + + <programlisting># /etc/systemd/network/25-bridge-slave-interface-2.network +[Match] +Name=wlp3s0 + +[Network] +Bridge=bridge0</programlisting> + + <para>This creates a bridge and attaches devices <literal>enp2s0</literal> and + <literal>wlp3s0</literal> to it. The bridge will have the specified static address + and network assigned, and a default route via the specified gateway will be + added. The specified DNS server will be added to the global list of DNS resolvers. + </para> + </example> + + <example> + <title></title> + + <programlisting> +# /etc/systemd/network/20-bridge-slave-interface-vlan.network +[Match] +Name=enp2s0 + +[Network] +Bridge=bridge0 + +[BridgeVLAN] +VLAN=1-32 +PVID=42 +EgressUntagged=42 + +[BridgeVLAN] +VLAN=100-200 + +[BridgeVLAN] +EgressUntagged=300-400</programlisting> + + <para>This overrides the configuration specified in the previous example for the + interface <literal>enp2s0</literal>, and enables VLAN on that bridge port. VLAN IDs + 1-32, 42, 100-400 will be allowed. Packets tagged with VLAN IDs 42, 300-400 will be + untagged when they leave on this interface. Untagged packets which arrive on this + interface will be assigned VLAN ID 42.</para> + </example> + + <example> + <title>Various tunnels</title> + + <programlisting>/etc/systemd/network/25-tunnels.network +[Match] +Name=ens1 + +[Network] +Tunnel=ipip-tun +Tunnel=sit-tun +Tunnel=gre-tun +Tunnel=vti-tun + </programlisting> + + <programlisting>/etc/systemd/network/25-tunnel-ipip.netdev +[NetDev] +Name=ipip-tun +Kind=ipip + </programlisting> + + <programlisting>/etc/systemd/network/25-tunnel-sit.netdev +[NetDev] +Name=sit-tun +Kind=sit + </programlisting> + + <programlisting>/etc/systemd/network/25-tunnel-gre.netdev +[NetDev] +Name=gre-tun +Kind=gre + </programlisting> + + <programlisting>/etc/systemd/network/25-tunnel-vti.netdev +[NetDev] +Name=vti-tun +Kind=vti + </programlisting> + + <para>This will bring interface <literal>ens1</literal> up and create an IPIP tunnel, + a SIT tunnel, a GRE tunnel, and a VTI tunnel using it.</para> + </example> + + <example> + <title>A bond device</title> + + <programlisting># /etc/systemd/network/30-bond1.network +[Match] +Name=bond1 + +[Network] +DHCP=ipv6 +</programlisting> + + <programlisting># /etc/systemd/network/30-bond1.netdev +[NetDev] +Name=bond1 +Kind=bond +</programlisting> + + <programlisting># /etc/systemd/network/30-bond1-dev1.network +[Match] +MACAddress=52:54:00:e9:64:41 + +[Network] +Bond=bond1 +</programlisting> + + <programlisting># /etc/systemd/network/30-bond1-dev2.network +[Match] +MACAddress=52:54:00:e9:64:42 + +[Network] +Bond=bond1 +</programlisting> + + <para>This will create a bond device <literal>bond1</literal> and enslave the two + devices with MAC addresses 52:54:00:e9:64:41 and 52:54:00:e9:64:42 to it. IPv6 DHCP + will be used to acquire an address.</para> + </example> + + <example> + <title>Virtual Routing and Forwarding (VRF)</title> + <para>Add the <literal>bond1</literal> interface to the VRF master interface + <literal>vrf1</literal>. This will redirect routes generated on this interface to be + within the routing table defined during VRF creation. For kernels before 4.8 traffic + won't be redirected towards the VRFs routing table unless specific ip-rules are added. + </para> + <programlisting># /etc/systemd/network/25-vrf.network +[Match] +Name=bond1 + +[Network] +VRF=vrf1 +</programlisting> + </example> + + <example> + <title>MacVTap</title> + <para>This brings up a network interface <literal>macvtap-test</literal> + and attaches it to <literal>enp0s25</literal>.</para> + <programlisting># /usr/lib/systemd/network/25-macvtap.network +[Match] +Name=enp0s25 + +[Network] +MACVTAP=macvtap-test +</programlisting> + </example> + + <example> + <title>A Xfrm interface with physical underlying device.</title> + + <programlisting># /etc/systemd/network/27-xfrm.netdev +[NetDev] +Name=xfrm0 + +[Xfrm] +InterfaceId=7</programlisting> + + <programlisting># /etc/systemd/network/27-eth0.network +[Match] +Name=eth0 + +[Network] +Xfrm=xfrm0</programlisting> + + <para>This creates a <literal>xfrm0</literal> interface and binds it to the <literal>eth0</literal> device. + This allows hardware based ipsec offloading to the <literal>eth0</literal> nic. + If offloading is not needed, xfrm interfaces can be assigned to the <literal>lo</literal> device. + </para> + </example> + </refsect1> + + <refsect1> + <title>See Also</title> + <para> + <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd.link</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> |