| <?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*--> |
| <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" |
| "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> |
| |
| <!-- |
| This file is part of systemd. |
| |
| Copyright 2013 Tom Gundersen |
| |
| systemd is free software; you can redistribute it and/or modify it |
| under the terms of the GNU Lesser General Public License as published by |
| the Free Software Foundation; either version 2.1 of the License, or |
| (at your option) any later version. |
| |
| systemd is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with systemd; If not, see <http://www.gnu.org/licenses/>. |
| --> |
| |
| <refentry id="systemd.network" conditional='ENABLE_NETWORKD'> |
| |
| <refentryinfo> |
| <title>systemd.network</title> |
| <productname>systemd</productname> |
| |
| <authorgroup> |
| <author> |
| <contrib>Developer</contrib> |
| <firstname>Tom</firstname> |
| <surname>Gundersen</surname> |
| <email>teg@jklm.no</email> |
| </author> |
| </authorgroup> |
| </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>Network setup is performed by |
| <citerefentry><refentrytitle>systemd-networkd</refentrytitle><manvolnum>8</manvolnum></citerefentry>. |
| </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 directory <filename>/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 in <filename>/lib</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>/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>/lib</filename>. Drop-in files under any of these |
| directories take precedence over the main netdev file wherever located. (Of course, since |
| <filename>/run</filename> is temporary and <filename>/lib</filename> is for vendors, it is |
| unlikely drop-ins should be used in either of those places.)</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 <literal>[Match]</literal> |
| section, which determines if a given network file may be applied |
| to a given device; and a <literal>[Network]</literal> 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 device if each of the |
| entries in the <literal>[Match]</literal> section matches, or if |
| the section is empty. The following keys are accepted:</para> |
| |
| <variablelist class='network-directives'> |
| <varlistentry> |
| <term><varname>MACAddress=</varname></term> |
| <listitem> |
| <para>The hardware address of the interface (use full colon-delimited hexadecimal, e.g., |
| 01:23:45:67:89:ab).</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>Path=</varname></term> |
| <listitem> |
| <para>A whitespace-separated list of shell-style globs |
| matching the persistent path, as exposed by the udev |
| property <literal>ID_PATH</literal>. If the list is |
| prefixed with a "!", the test is inverted; i.e. it is |
| true when <literal>ID_PATH</literal> does not match any |
| item in the list.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>Driver=</varname></term> |
| <listitem> |
| <para>A whitespace-separated list of shell-style globs |
| matching the driver currently bound to the device, as |
| exposed by the udev property <literal>DRIVER</literal> |
| of its parent device, or if that is not set the driver |
| as exposed by <literal>ethtool -i</literal> of the |
| device itself. If the list is prefixed with a "!", the |
| test is inverted.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>Type=</varname></term> |
| <listitem> |
| <para>A whitespace-separated list of shell-style globs |
| matching the device type, as exposed by the udev property |
| <literal>DEVTYPE</literal>. If the list is prefixed with |
| a "!", the test is inverted.</para> |
| </listitem> |
| </varlistentry> |
| <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>. If the list is prefixed |
| with a "!", the test is inverted.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>Host=</varname></term> |
| <listitem> |
| <para>Matches against the hostname or machine ID of the |
| host. See <literal>ConditionHost=</literal> in |
| <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry> |
| for details. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>Virtualization=</varname></term> |
| <listitem> |
| <para>Checks whether the system is executed in a virtualized |
| environment and optionally test whether it is a specific |
| implementation. See <literal>ConditionVirtualization=</literal> in |
| <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry> |
| for details. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>KernelCommandLine=</varname></term> |
| <listitem> |
| <para>Checks whether a specific kernel command line option is |
| set (or if prefixed with the exclamation mark unset). See |
| <literal>ConditionKernelCommandLine=</literal> in |
| <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry> |
| for details. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>Architecture=</varname></term> |
| <listitem> |
| <para>Checks whether the system is running on a specific |
| architecture. See <literal>ConditionArchitecture=</literal> in |
| <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry> |
| for details. |
| </para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| |
| </refsect1> |
| |
| <refsect1> |
| <title>[Link] Section Options</title> |
| |
| <para> The <literal>[Link]</literal> 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> A boolean. Enables or disables the ARP (low-level Address Resolution Protocol) |
| for this interface. Defaults to unset, which means that the kernel 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>Unmanaged=</varname></term> |
| <listitem> |
| <para>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> |
| </variablelist> |
| </refsect1> |
| |
| <refsect1> |
| <title>[Network] Section Options</title> |
| |
| <para>The <literal>[Network]</literal> 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>.</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 <literal>[DHCP]</literal> section below for further configuration options for the DHCP client |
| support.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>DHCPServer=</varname></term> |
| <listitem> |
| <para>A boolean. Enables DHCPv4 server support. Defaults |
| to <literal>no</literal>. Further settings for the DHCP |
| server may be set in the <literal>[DHCPServer]</literal> |
| 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>, or <literal>ipv6</literal>. Defaults to |
| <literal>ipv6</literal>.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>IPv4LLRoute=</varname></term> |
| <listitem> |
| <para>A boolean. When 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>IPv6Token=</varname></term> |
| <listitem> |
| <para>An IPv6 address with the top 64 bits unset. When set, indicates the |
| 64-bit interface part of SLAAC IPv6 addresses for this link. Note that |
| the token is only ever used for SLAAC, and not for DHCPv6 addresses, even |
| in the case DHCP is requested by router advertisement. By default, the |
| token is autogenerated.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>LLMNR=</varname></term> |
| <listitem> |
| <para>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>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>DNSSEC=</varname></term> |
| <listitem> |
| <para>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 DNSEC 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 host name, 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="http://standards.ieee.org/getieee802/download/802.1AB-2009.pdf">IEEE 802.1AB-2009</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 0.0.0.0 (for IPv4) or |
| [::] (for IPv6), a new address range of the requested size |
| is automatically allocated from a system-wide pool of |
| unused ranges. 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 fc00::/7 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. 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 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 host names (host names containing no dots) to |
| become fully qualified domain names (FQDNs). If a single-label host name 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 host names |
| 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>NTP=</varname></term> |
| <listitem> |
| <para>An NTP server address. 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 either a boolean |
| argument, 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>Enable or disable IPv6 Router Advertisement (RA) reception support for the interface. Takes |
| a boolean parameter. If true, RAs are accepted; if false, RAs are ignored, independently of the local |
| forwarding state. When not set, the kernel default is used, and RAs are accepted only when local forwarding |
| is disabled for that interface. 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.</para> |
| |
| <para>Further settings for the IPv6 RA support may be configured in the |
| <literal>[IPv6AcceptRA]</literal> 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> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>IPv6DuplicateAddressDetection=</varname></term> |
| <listitem><para>Configures the amount of IPv6 Duplicate |
| Address Detection (DAD) probes to send. Defaults to unset. |
| </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. |
| Defaults to unset. |
| </para></listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>IPv4ProxyARP=</varname></term> |
| <listitem><para>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>. |
| Defaults to unset. |
| </para></listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>IPv6ProxyNDP=</varname></term> |
| <listitem><para>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. |
| Defautls to unset. |
| </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=true</option> but has no effect if |
| <option>IPv6ProxyNDP</option> has been set to false. Defaults to unset. |
| </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>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> |
| </variablelist> |
| |
| </refsect1> |
| |
| <refsect1> |
| <title>[Address] Section Options</title> |
| |
| <para>An <literal>[Address]</literal> section accepts the |
| following keys. Specify several <literal>[Address]</literal> |
| sections to configure several addresses.</para> |
| |
| <variablelist class='network-directives'> |
| <varlistentry> |
| <term><varname>Address=</varname></term> |
| <listitem> |
| <para>As in the <literal>[Network]</literal> section. This |
| key is mandatory.</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 <literal>Address</literal> |
| 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 <literal>Address</literal> |
| 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>HomeAddress=</varname></term> |
| <listitem> |
| <para>Takes a boolean argument. 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 a boolean argument. Do not perform Duplicate Address Detection |
| <ulink url="https://tools.ietf.org/html/rfc4862">RFC 4862</ulink> when adding this address. |
| Supported only on IPv6. Defaults to false.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>ManageTemporaryAddress=</varname></term> |
| <listitem> |
| <para>Takes a boolean argument. 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 to use privacy |
| extensions in a manually configured network, just like if stateless auto-configuration |
| was active. Defaults to false. </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>PrefixRoute=</varname></term> |
| <listitem> |
| <para>Takes a boolean argument. When adding or modifying an IPv6 address, the userspace |
| application needs a way to suppress adding a prefix route. This is for example relevant |
| together with IFA_F_MANAGERTEMPADDR, where userspace creates autoconf generated addresses, |
| but depending on on-link, no route for the prefix should be added. Defaults to false.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>AutoJoin=</varname></term> |
| <listitem> |
| <para>Takes a boolean argument. 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>[IPv6AddressLabel] Section Options</title> |
| |
| <para>An <literal>[IPv6AddressLabel]</literal> section accepts the |
| following keys. Specify several <literal>[IPv6AddressLabel]</literal> |
| sections to configure several addresse 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) ranges 0 to 4294967294. |
| 0xffffffff is reserved. This key 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>[Route] Section Options</title> |
| <para>The <literal>[Route]</literal> section accepts the |
| following keys. Specify several <literal>[Route]</literal> |
| sections to configure several routes.</para> |
| |
| <variablelist class='network-directives'> |
| <varlistentry> |
| <term><varname>Gateway=</varname></term> |
| <listitem> |
| <para>As in the <literal>[Network]</literal> section.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>GatewayOnlink=</varname></term> |
| <listitem> |
| <para>The <literal>GatewayOnlink</literal> option tells the kernel that it 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. A boolean, 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">RFC4191</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 route, which can be <literal>global</literal>, |
| <literal>link</literal> or <literal>host</literal>. Defaults to |
| <literal>global</literal>.</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=<replaceable>num</replaceable></varname></term> |
| <listitem> |
| <para>The table identifier for the route (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>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> and <literal>static</literal>. Defaults to |
| <literal>static</literal>. |
| </para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </refsect1> |
| |
| <refsect1> |
| <title>[DHCP] Section Options</title> |
| <para>The <literal>[DHCP]</literal> section configures the |
| DHCPv4 and DHCP6 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>UseNTP=</varname></term> |
| <listitem> |
| <para>When true (the default), the NTP servers received |
| from the DHCP server will be used by systemd-timesyncd |
| and take precedence over any statically configured ones.</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. |
| Defaults to false.</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.</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.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>UseDomains=</varname></term> |
| <listitem> |
| <para>Takes a boolean argument, 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 host names, 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>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>CriticalConnection=</varname></term> |
| <listitem> |
| <para>When true, the connection will never be torn down |
| even if the DHCP lease expires. This is contrary to the |
| DHCP specification, but may be the best choice if, say, |
| the root filesystem relies on this connection. Defaults to |
| false.</para> |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>ClientIdentifier=</varname></term> |
| <listitem> |
| <para>The DHCPv4 client identifier to use. Either <literal>mac</literal> to use the MAC address of the link |
| or <literal>duid</literal> (the default, see below) to use an RFC4361-compliant Client ID.</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>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.</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> |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>ListenPort=</varname></term> |
| <listitem> |
| <para>Allow setting custom port for the DHCP client to listen on.</para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </refsect1> |
| |
| <refsect1> |
| <title>[IPv6AcceptRA] Section Options</title> |
| <para>The <literal>[IPv6AcceptRA]</literal> 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 argument, 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 host names, 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> |
| </variablelist> |
| </refsect1> |
| |
| |
| <refsect1> |
| <title>[DHCPServer] Section Options</title> |
| <para>The <literal>[DHCPServer]</literal> 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>Configures whether the DHCP leases handed out |
| to clients shall contain DNS server information. The |
| <varname>EmitDNS=</varname> setting takes a boolean argument |
| and 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 or NTP server information at a |
| later point. DNS server propagation does not take |
| <filename>/etc/resolv.conf</filename> into account. 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> |
| |
| <listitem><para>Similar to the <varname>EmitDNS=</varname> and |
| <varname>DNS=</varname> settings described above, these |
| settings configure whether and what NTP server information |
| 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>Configures whether the DHCP leases handed out |
| to clients shall contain timezone information. The |
| <varname>EmitTimezone=</varname> setting takes a boolean |
| argument and 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> |
| |
| </variablelist> |
| </refsect1> |
| |
| <refsect1> |
| <title>[Bridge] Section Options</title> |
| <para>The <literal>[Bridge]</literal> section accepts the |
| following keys.</para> |
| <variablelist class='network-directives'> |
| <varlistentry> |
| <term><varname>UnicastFlood=</varname></term> |
| <listitem> |
| <para>A boolean. Controls whether the bridge should flood |
| traffic for which an FDB entry is missing and the destination |
| is unknown through this port. Defaults to on. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>HairPin=</varname></term> |
| <listitem> |
| <para>A boolean. Configures whether traffic may be sent back |
| out of the port on which it was received. By default, this |
| flag is false, and the bridge will not forward traffic back |
| out of the receiving port.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>UseBPDU=</varname></term> |
| <listitem> |
| <para>A boolean. Configures whether STP Bridge Protocol Data Units will be |
| processed by the bridge port. Defaults to yes.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>FastLeave=</varname></term> |
| <listitem> |
| <para>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. Defaults to off.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>AllowPortToBeRoot=</varname></term> |
| <listitem> |
| <para>A boolean. Configures whether a given port is allowed to |
| become a root port. Only used when STP is enabled on the bridge. |
| Defaults to on.</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 interger 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 interger 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 <literal>[BridgeFDB]</literal> section manages the |
| forwarding database table of a port and accepts the following |
| keys. Specify several <literal>[BridgeFDB]</literal> sections to |
| configure several static MAC table entries.</para> |
| |
| <variablelist class='network-directives'> |
| <varlistentry> |
| <term><varname>MACAddress=</varname></term> |
| <listitem> |
| <para>As in the <literal>[Network]</literal> section. This |
| key is mandatory.</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 info is appended to the new static MAC |
| table entry.</para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </refsect1> |
| <refsect1> |
| <title>[BridgeVLAN] Section Options</title> |
| <para>The <literal>[BridgeVLAN]</literal> section manages the VLAN ID configuration of a bridge port and accepts |
| the following keys. Specify several <literal>[BridgeVLAN]</literal> sections to configure several VLAN entries. |
| The <varname>VLANFiltering=</varname> option has to be enabled, see <literal>[Bridge]</literal> 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>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. 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># /lib/systemd/network/25-macvtap.network |
| [Match] |
| Name=enp0s25 |
| |
| [Network] |
| MACVTAP=macvtap-test |
| </programlisting> |
| </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> |