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| Copyright 2013 Tom Gundersen |
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| |
| <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>Network files 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>/usr/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>/usr/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> |
| </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.</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>.</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.</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>.</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>.</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.</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> |
| </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 |
| Advertisment, 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>IPv6AcceptRouterAdvertisements=</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> |
| </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. By default, |
| it is autogenerated.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>LLMNR=</varname></term> |
| <listitem> |
| <para>A boolean or <literal>resolve</literal>. When true, enables |
| Link-Local Multicast Name Resolution on the link. When set to |
| <literal>resolve</literal>, only resolution is enabled, but not |
| announcement. Defaults to true.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>LLDP=</varname></term> |
| <listitem> |
| <para>A boolean. When true, enables LLDP link receive support. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>BindCarrier=</varname></term> |
| <listitem> |
| <para>A port or a list of ports. When set, controls the |
| behavior of the current interface. When all ports in the list |
| are in an operational down state, the current interface is brought |
| down. When at least one port 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.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>Domains=</varname></term> |
| <listitem> |
| <para>The domains used for DNS resolution over this link.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>NTP=</varname></term> |
| <listitem> |
| <para>An NTP server address. This option may be specified more than once.</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>IPv6AcceptRouterAdvertisements=</varname></term> |
| <listitem><para>Force the setting of the <filename>accept_ra</filename> |
| (router advertisements) setting for the interface. |
| When unset, the kernel default is used, and router |
| advertisements are accepted only when local forwarding |
| is disabled for that interface. |
| When router advertisements are accepted, they will |
| trigger the start of the DHCPv6 client if the relevant |
| flags are passed, or if no routers are found on the link. |
| Takes a boolean. If true, router advertisements are |
| accepted, when false, router advertisements are ignored, |
| independently of the local forwarding state.</para> |
| |
| <para>See |
| <ulink url="https://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt">ip-sysctl.txt</ulink> |
| in the kernel documentation, but note that systemd's |
| setting of <constant>1</constant> 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>Bridge=</varname></term> |
| <listitem> |
| <para>The name of the bridge to add the link to.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>Bond=</varname></term> |
| <listitem> |
| <para>The name of the bond to add the link to.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><varname>VLAN=</varname></term> |
| <listitem> |
| <para>The name of a VLAN to create on the link. 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. 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. 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. 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> |
| </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>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>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> |
| </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>When true (not the default), the domain name |
| received from the DHCP server will be used for DNS |
| resolution over this link. When a name cannot be resolved |
| as specified, the domain name will be used a suffix and |
| name resolution of that will be attempted.</para> |
| |
| <para>This corresponds to the <option>domain</option> |
| option in <citerefentry project='man-pages'><refentrytitle>resolv.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry> |
| and should not be enabled on untrusted networks.</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.</para> |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>UseTimezone=</varname></term> |
| |
| <listitem><para>When true, the timezone received from the |
| DHCP server will be set as 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>DHCP client identifier to use. Either <literal>mac</literal> |
| to use the MAC address of the link or <literal>duid</literal> |
| (the default) to use a 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>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> |
| </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>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.</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>Example</title> |
| <example> |
| <title>/etc/systemd/network/50-static.network</title> |
| |
| <programlisting>[Match] |
| Name=enp2s0 |
| |
| [Network] |
| Address=192.168.0.15/24 |
| Gateway=192.168.0.1</programlisting> |
| </example> |
| |
| <example> |
| <title>/etc/systemd/network/80-dhcp.network</title> |
| |
| <programlisting>[Match] |
| Name=en* |
| |
| [Network] |
| DHCP=yes</programlisting> |
| </example> |
| |
| <example> |
| <title>/etc/systemd/network/25-bridge-static.network</title> |
| |
| <programlisting>[Match] |
| Name=bridge0 |
| |
| [Network] |
| Address=192.168.0.15/24 |
| Gateway=192.168.0.1 |
| DNS=192.168.0.1</programlisting> |
| </example> |
| |
| <example> |
| <title>/etc/systemd/network/25-bridge-slave-interface.network</title> |
| |
| <programlisting>[Match] |
| Name=enp2s0 |
| |
| [Network] |
| Bridge=bridge0</programlisting> |
| </example> |
| <example> |
| <title>/etc/systemd/network/25-ipip.network</title> |
| |
| <programlisting>[Match] |
| Name=em1 |
| |
| [Network] |
| Tunnel=ipip-tun</programlisting> |
| </example> |
| |
| <example> |
| <title>/etc/systemd/network/25-sit.network</title> |
| |
| <programlisting>[Match] |
| Name=em1 |
| |
| [Network] |
| Tunnel=sit-tun</programlisting> |
| </example> |
| |
| <example> |
| <title>/etc/systemd/network/25-gre.network</title> |
| |
| <programlisting>[Match] |
| Name=em1 |
| |
| [Network] |
| Tunnel=gre-tun</programlisting> |
| </example> |
| |
| <example> |
| <title>/etc/systemd/network/25-vti.network</title> |
| |
| <programlisting>[Match] |
| Name=em1 |
| |
| [Network] |
| Tunnel=vti-tun</programlisting> |
| </example> |
| |
| <example> |
| <title>/etc/systemd/network/25-bond.network</title> |
| |
| <programlisting>[Match] |
| Name=bond1 |
| |
| [Network] |
| DHCP=yes |
| </programlisting> |
| </example> |
| |
| </refsect1> |
| |
| <refsect1> |
| <title>See Also</title> |
| <para> |
| <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, |
| <citerefentry><refentrytitle>systemd-networkd</refentrytitle><manvolnum>8</manvolnum></citerefentry>, |
| <citerefentry><refentrytitle>systemd.link</refentrytitle><manvolnum>5</manvolnum></citerefentry>, |
| <citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry> |
| </para> |
| </refsect1> |
| |
| </refentry> |