systemd.network - Network configuration
A plain ini-style text file that encodes network configuration for
matching network interfaces, used by systemd-networkd(8). See
systemd.syntax(7) for a general description of the syntax.
The main network file must have the extension .network; other
extensions are ignored. Networks are applied to links whenever the links
appear.
The .network files are read from the files located in the system
network directories /lib/systemd/network and /usr/local/lib/systemd/network,
the volatile runtime network directory /run/systemd/network and the local
administration network directory /etc/systemd/network. 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 /etc/ have the highest priority, files in /run/
take precedence over files with the same name under /usr/. 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 /dev/null disables the configuration file entirely (it
is "masked").
Along with the network file foo.network, a "drop-in"
directory foo.network.d/ may exist. All files with the suffix
".conf" 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.
In addition to /etc/systemd/network, drop-in ".d"
directories can be placed in /lib/systemd/network or /run/systemd/network
directories. Drop-in files in /etc/ take precedence over those in /run/
which in turn take precedence over those in /lib/. Drop-in files under any
of these directories take precedence over the main network file wherever
located.
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
/proc/sys/net/ipv6/conf/ifname/disable_ipv6.
The network file contains a [Match] section, which determines if a
given network file may be applied to a given device; and a [Network] section
specifying how the device should be configured. The first (in lexical order)
of the network files that matches a given device is applied, all later files
are ignored, even if they match as well.
A network file is said to match a network interface if all matches
specified by the [Match] section are satisfied. When a network file does not
contain valid settings in [Match] section, then the file will match all
interfaces and systemd-networkd warns about that. Hint: to avoid the
warning and to make it clear that all interfaces shall be matched, add the
following:
The following keys are accepted:
MACAddress=
A whitespace-separated list of hardware addresses. Use
full colon-, hyphen- or dot-delimited hexadecimal. See the example below. This
option may appear more than once, in which case the lists are merged. If the
empty string is assigned to this option, the list of hardware addresses
defined prior to this is reset.
Example:
MACAddress=01:23:45:67:89:ab 00-11-22-33-44-55 AABB.CCDD.EEFF
PermanentMACAddress=
A whitespace-separated list of hardware's permanent
addresses. While MACAddress= matches the device's current MAC address,
this matches the device's permanent MAC address, which may be different from
the current one. Use full colon-, hyphen- or dot-delimited hexadecimal. This
option may appear more than once, in which case the lists are merged. If the
empty string is assigned to this option, the list of hardware addresses
defined prior to this is reset.
Path=
A whitespace-separated list of shell-style globs matching
the persistent path, as exposed by the udev property ID_PATH.
Driver=
A whitespace-separated list of shell-style globs matching
the driver currently bound to the device, as exposed by the udev property
ID_NET_DRIVER of its parent device, or if that is not set, the driver
as exposed by ethtool -i of the device itself. If the list is prefixed
with a "!", the test is inverted.
Type=
A whitespace-separated list of shell-style globs matching
the device type, as exposed by networkctl status. If the list is
prefixed with a "!", the test is inverted.
Property=
A whitespace-separated list of udev property name with
its value after a equal ("="). If multiple properties are specified,
the test results are ANDed. If the list is prefixed with a "!", the
test is inverted. If a value contains white spaces, then please quote whole
key and value pair. If a value contains quotation, then please escape the
quotation with "\".
Example: if a .link file has the following:
Property=ID_MODEL_ID=9999 "ID_VENDOR_FROM_DATABASE=vendor name" "KEY=with \"quotation\""
then, the .link file matches only when an interface has all the
above three properties.
Name=
A whitespace-separated list of shell-style globs matching
the device name, as exposed by the udev property "INTERFACE", or
device's alternative names. If the list is prefixed with a "!", the
test is inverted.
WLANInterfaceType=
A whitespace-separated list of wireless network type.
Supported values are "ad-hoc", "station", "ap",
"ap-vlan", "wds", "monitor",
"mesh-point", "p2p-client", "p2p-go",
"p2p-device", "ocb", and "nan". If the list is
prefixed with a "!", the test is inverted.
SSID=
A whitespace-separated list of shell-style globs matching
the SSID of the currently connected wireless LAN. If the list is prefixed with
a "!", the test is inverted.
BSSID=
A whitespace-separated list of hardware address of the
currently connected wireless LAN. Use full colon-, hyphen- or dot-delimited
hexadecimal. See the example in MACAddress=. This option may appear
more than once, in which case the lists are merged. If the empty string is
assigned to this option, the list is reset.
Host=
Matches against the hostname or machine ID of the host.
See
ConditionHost= in
systemd.unit(5) for details. When prefixed
with an exclamation mark ("!"), the result is negated. If an empty
string is assigned, then previously assigned value is cleared.
Virtualization=
Checks whether the system is executed in a virtualized
environment and optionally test whether it is a specific implementation. See
ConditionVirtualization= in
systemd.unit(5) for details. When
prefixed with an exclamation mark ("!"), the result is negated. If
an empty string is assigned, then previously assigned value is cleared.
KernelCommandLine=
Checks whether a specific kernel command line option is
set. See
ConditionKernelCommandLine= in
systemd.unit(5) for
details. When prefixed with an exclamation mark ("!"), the result is
negated. If an empty string is assigned, then previously assigned value is
cleared.
KernelVersion=
Checks whether the kernel version (as reported by
uname -r) matches a certain expression. See
ConditionKernelVersion= in
systemd.unit(5) for details. When
prefixed with an exclamation mark ("!"), the result is negated. If
an empty string is assigned, then previously assigned value is cleared.
Architecture=
Checks whether the system is running on a specific
architecture. See
ConditionArchitecture= in
systemd.unit(5) for
details. When prefixed with an exclamation mark ("!"), the result is
negated. If an empty string is assigned, then previously assigned value is
cleared.
The [Link] section accepts the following keys:
MACAddress=
The hardware address to set for the device.
MTUBytes=
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.
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.
ARP=
Takes a boolean. If set to true, the ARP (low-level
Address Resolution Protocol) for this interface is enabled. When unset, the
kernel's default will be used.
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.
Multicast=
Takes a boolean. If set to true, the multicast flag on
the device is enabled.
AllMulticast=
Takes a boolean. If set to true, the driver retrieves all
multicast packets from the network. This happens when multicast routing is
enabled.
Unmanaged=
Takes a boolean. When "yes", no attempts are
made to bring up or configure matching links, equivalent to when there are no
matching network files. Defaults to "no".
This is useful for preventing later matching network files from
interfering with certain interfaces that are fully controlled by other
applications.
Group=
Link groups are similar to port ranges found in managed
switches. When network interfaces are added to a numbered group, operations on
all the interfaces from that group can be performed at once. An unsigned
integer in the range 0—4294967294. Defaults to unset.
RequiredForOnline=
Takes a boolean or a minimum operational state and an
optional maximum operational state. Please see
networkctl(1) for
possible operational states. When "yes", the network is deemed
required when determining whether the system is online when running
systemd-networkd-wait-online. When "no", the network is
ignored when checking for online state. When a minimum operational state and
an optional maximum operational state are set, "yes" is implied, and
this controls the minimum and maximum operational state required for the
network interface to be considered online. Defaults to "yes".
The network will be brought up normally in all cases, but in the
event that there is no address being assigned by DHCP or the cable is not
plugged in, the link will simply remain offline and be skipped automatically
by systemd-networkd-wait-online if
"RequiredForOnline=no".
The [SR-IOV] section accepts the following keys. Specify several
[SR-IOV] sections to configure several SR-IOVs. SR-IOV provides the ability
to partition a single physical PCI resource into virtual PCI functions which
can then be injected into a VM. In the case of network VFs, SR-IOV improves
north-south network performance (that is, traffic with endpoints outside the
host machine) by allowing traffic to bypass the host machine’s
network stack.
VirtualFunction=
Specifies a Virtual Function (VF), lightweight PCIe
function designed solely to move data in and out. Takes an unsigned integer in
the range 0..2147483646. This option is compulsory.
VLANId=
Specifies VLAN ID of the virtual function. Takes an
unsigned integer in the range 1..4095.
QualityOfService=
Specifies quality of service of the virtual function.
Takes an unsigned integer in the range 1..4294967294.
VLANProtocol=
Specifies VLAN protocol of the virtual function. Takes
"802.1Q" or "802.1ad".
MACSpoofCheck=
Takes a boolean. Controls the MAC spoof checking. When
unset, the kernel's default will be used.
QueryReceiveSideScaling=
Takes a boolean. Toggle the ability of querying the
receive side scaling (RSS) configuration of the virtual function (VF). The VF
RSS information like RSS hash key may be considered sensitive on some devices
where this information is shared between VF and the physical function (PF).
When unset, the kernel's default will be used.
Trust=
Takes a boolean. Allows to set trust mode of the virtual
function (VF). When set, VF users can set a specific feature which may impact
security and/or performance. When unset, the kernel's default will be
used.
LinkState=
Allows to set the link state of the virtual function
(VF). Takes a boolean or a special value "auto". Setting to
"auto" means a reflection of the physical function (PF) link state,
"yes" lets the VF to communicate with other VFs on this host even if
the PF link state is down, "no" causes the hardware to drop any
packets sent by the VF. When unset, the kernel's default will be used.
MACAddress=
Specifies the MAC address for the virtual function.
The [Network] section accepts the following keys:
Description=
A description of the device. This is only used for
presentation purposes.
DHCP=
Enables DHCPv4 and/or DHCPv6 client support. Accepts
"yes", "no", "ipv4", or "ipv6".
Defaults to "no".
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
"IPv6AcceptRA=".
Furthermore, note that by default the domain name specified
through DHCP is not used for name resolution. See option UseDomains=
below.
See the [DHCPv4] or [DHCPv6] sections below for further
configuration options for the DHCP client support.
DHCPServer=
Takes a boolean. If set to "yes", DHCPv4 server
will be started. Defaults to "no". Further settings for the DHCP
server may be set in the [DHCPServer] section described below.
LinkLocalAddressing=
Enables link-local address autoconfiguration. Accepts
"yes", "no", "ipv4", "ipv6",
"fallback", or "ipv4-fallback". If "fallback" or
"ipv4-fallback" is specified, then an IPv4 link-local address is
configured only when DHCPv4 fails. If "fallback", an IPv6 link-local
address is always configured, and if "ipv4-fallback", the address is
not configured. Note that, the fallback mechanism works only when DHCPv4
client is enabled, that is, it requires "DHCP=yes" or
"DHCP=ipv4". If Bridge= is set, defaults to "no",
and if not, defaults to "ipv6".
IPv6LinkLocalAddressGenerationMode=
Specifies how IPv6 link local address is generated. Takes
one of "eui64", "none", "stable-privacy" and
"random". When unset, the kernel's default will be used. Note that
if LinkLocalAdressing= not configured as "ipv6" then
IPv6LinkLocalAddressGenerationMode= is ignored.
IPv4LLRoute=
Takes a boolean. If set to true, sets up the route needed
for non-IPv4LL hosts to communicate with IPv4LL-only hosts. Defaults to
false.
DefaultRouteOnDevice=
Takes a boolean. If set to true, sets up the default
route bound to the interface. Defaults to false. This is useful when creating
routes on point-to-point interfaces. This is equivalent to e.g. the following.
ip route add default dev veth99
IPv6Token=
Specifies an optional address generation mode for the
Stateless Address Autoconfiguration (SLAAC). Supported modes are
"prefixstable" and "static".
When the mode is set to "static", an IPv6 address must
be specified after a colon (":"), and the lower bits of the
supplied address are combined with the upper bits of a prefix received in a
Router Advertisement (RA) message to form a complete address. Note that if
multiple prefixes are received in an RA message, or in multiple RA messages,
addresses will be formed from each of them using the supplied address. This
mode implements SLAAC but uses a static interface identifier instead of an
identifier generated by using the EUI-64 algorithm. Because the interface
identifier is static, if Duplicate Address Detection detects that the
computed address is a duplicate (in use by another node on the link), then
this mode will fail to provide an address for that prefix. If an IPv6
address without mode is specified, then "static" mode is
assumed.
When the mode is set to "prefixstable" the RFC
7217[1] algorithm for generating interface identifiers will be used.
This mode can optionally take an IPv6 address separated with a colon
(":"). If an IPv6 address is specified, then an interface
identifier is generated only when a prefix received in an RA message matches
the supplied address.
If no address generation mode is specified (which is the default),
or a received prefix does not match any of the addresses provided in
"prefixstable" mode, then the EUI-64 algorithm will be used to
form an interface identifier for that prefix. This mode is also SLAAC, but
with a potentially stable interface identifier which does not directly map
to the interface's hardware address.
Note that the "prefixstable" algorithm uses both the
interface name and MAC address as input to the hash to compute the interface
identifier, so if either of those are changed the resulting interface
identifier (and address) will change, even if the prefix received in the RA
message has not changed.
This setting can be specified multiple times. If an empty string
is assigned, then the all previous assignments are cleared.
Examples:
IPv6Token=::1a:2b:3c:4d
IPv6Token=static:::1a:2b:3c:4d
IPv6Token=prefixstable
IPv6Token=prefixstable:2002:da8:1::
LLMNR=
Takes a boolean or "resolve". When true,
enables
Link-Local Multicast Name Resolution[2] on the link. When set
to "resolve", only resolution is enabled, but not host registration
and announcement. Defaults to true. This setting is read by
systemd-resolved.service(8).
MulticastDNS=
Takes a boolean or "resolve". When true,
enables
Multicast DNS[3] support on the link. When set to
"resolve", only resolution is enabled, but not host or service
registration and announcement. Defaults to false. This setting is read by
systemd-resolved.service(8).
DNSOverTLS=
Takes a boolean or "opportunistic". When true,
enables
DNS-over-TLS[4] support on the link. When set to
"opportunistic", compatibility with non-DNS-over-TLS servers is
increased, by automatically turning off DNS-over-TLS servers in this case.
This option defines a per-interface setting for
resolved.conf(5)'s
global
DNSOverTLS= option. Defaults to false. This setting is read by
systemd-resolved.service(8).
DNSSEC=
Takes a boolean or "allow-downgrade". When
true, enables
DNSSEC[5] DNS validation support on the link. When set to
"allow-downgrade", compatibility with non-DNSSEC capable networks is
increased, by automatically turning off DNSSEC in this case. This option
defines a per-interface setting for
resolved.conf(5)'s global
DNSSEC= option. Defaults to false. This setting is read by
systemd-resolved.service(8).
DNSSECNegativeTrustAnchors=
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
systemd-resolved.service(8).
LLDP=
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
"routers-only". When true, incoming LLDP packets are accepted and a
database of all LLDP neighbors maintained. If "routers-only" 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 "routers-only". Use
networkctl(1) to query the collected neighbor data. LLDP is only
available on Ethernet links. See
EmitLLDP= below for enabling LLDP
packet emission from the local system.
EmitLLDP=
Controls support for Ethernet LLDP packet emission.
Accepts a boolean parameter or the special values "nearest-bridge",
"non-tpmr-bridge" and "customer-bridge". Defaults to
false, which turns off LLDP packet emission. If not false, a short LLDP packet
with information about the local system is sent out in regular intervals on
the link. The LLDP packet will contain information about the local hostname,
the local machine ID (as stored in
machine-id(5)) and the local
interface name, as well as the pretty hostname of the system (as set in
machine-info(5)). 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
"nearest-bridge" setting permits propagation only to the nearest
connected bridge, "non-tpmr-bridge" permits propagation across
Two-Port MAC Relays, but not any other bridges, and
"customer-bridge" permits propagation until a customer bridge is
reached. For details about these concepts, see
IEEE 802.1AB-2016[6].
Note that configuring this setting to true is equivalent to
"nearest-bridge", the recommended and most restricted level of
propagation. See
LLDP= above for an option to enable LLDP
reception.
BindCarrier=
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.
Address=
A static IPv4 or IPv6 address and its prefix length,
separated by a "/" character. Specify this key more than once to
configure several addresses. The format of the address must be as described in
inet_pton(3). This is a short-hand for an [Address] section only
containing an Address key (see below). This option may be specified more than
once.
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. Note that
the prefix length must be equal or larger than 8 for IPv4, and 64 for IPv6.
The allocated range is checked against all current network interfaces and
all known network configuration files to avoid address range conflicts. The
default system-wide pool consists of 192.168.0.0/16, 172.16.0.0/12 and
10.0.0.0/8 for IPv4, and fd00::/8 for IPv6. This functionality is useful to
manage a large number of dynamically created network interfaces with the
same network configuration and automatic address range assignment.
Gateway=
The gateway address, which must be in the format
described in
inet_pton(3). This is a short-hand for a [Route] section
only containing a Gateway key. This option may be specified more than
once.
DNS=
A DNS server address, which must be in the format
described in
inet_pton(3). This option may be specified more than once.
Each address can optionally take a port number separated with ":", a
network interface name or index separated with "%", and a Server
Name Indication (SNI) separated with "#". When IPv6 address is
specified with a port number, then the address must be in the square brackets.
That is, the acceptable full formats are
"111.222.333.444:9953%ifname#example.com" for IPv4 and
"[1111:2222::3333]:9953%ifname#example.com" for IPv6. This setting
can be specified multiple times. If an empty string is assigned, then the all
previous assignments are cleared. This setting is read by
systemd-resolved.service(8).
Domains=
A whitespace-separated list of domains which should be
resolved using the DNS servers on this link. Each item in the list should be a
domain name, optionally prefixed with a tilde ("~"). The domains
with the prefix are called "routing-only domains". The domains
without the prefix are called "search domains" and are first used as
search suffixes for extending single-label hostnames (hostnames containing no
dots) to become fully qualified domain names (FQDNs). If a single-label
hostname is resolved on this interface, each of the specified search domains
are appended to it in turn, converting it into a fully qualified domain name,
until one of them may be successfully resolved.
Both "search" and "routing-only" domains are
used for routing of DNS queries: look-ups for hostnames ending in those
domains (hence also single label names, if any "search domains"
are listed), are routed to the DNS servers configured for this interface.
The domain routing logic is particularly useful on multi-homed hosts with
DNS servers serving particular private DNS zones on each interface.
The "routing-only" domain "~." (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.
This setting is read by systemd-resolved.service(8).
"Search domains" correspond to the domain and search
entries in resolv.conf(5). Domain name routing has no equivalent in
the traditional glibc API, which has no concept of domain name servers
limited to a specific link.
DNSDefaultRoute=
Takes a boolean argument. If true, this link's configured
DNS servers are used for resolving domain names that do not match any link's
configured Domains= setting. If false, this link's configured DNS
servers are never used for such domains, and are exclusively used for
resolving names that match at least one of the domains configured on this
link. If not specified defaults to an automatic mode: queries not matching any
link's configured domains will be routed to this link if it has no
routing-only domains configured.
NTP=
An NTP server address (either an IP address, or a
hostname). This option may be specified more than once. This setting is read
by
systemd-timesyncd.service(8).
IPForward=
Configures IP packet forwarding for the system. If
enabled, incoming packets on any network interface will be forwarded to any
other interfaces according to the routing table. Takes a boolean, or the
values "ipv4" or "ipv6", which only enable IP packet
forwarding for the specified address family. This controls the
net.ipv4.ip_forward and net.ipv6.conf.all.forwarding sysctl options of the
network interface (see
ip-sysctl.txt[7] for details about sysctl
options). Defaults to "no".
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.
To allow IP packet forwarding only between specific network
interfaces use a firewall.
IPMasquerade=
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 IPForward=ipv4.
Defaults to "no".
IPv6PrivacyExtensions=
Configures use of stateless temporary addresses that
change over time (see RFC 4941[8], Privacy Extensions for Stateless
Address Autoconfiguration in IPv6). Takes a boolean or the special values
"prefer-public" and "kernel". When true, enables the
privacy extensions and prefers temporary addresses over public addresses. When
"prefer-public", enables the privacy extensions, but prefers public
addresses over temporary addresses. When false, the privacy extensions remain
disabled. When "kernel", the kernel's default setting will be left
in place. Defaults to "no".
IPv6AcceptRA=
Takes a boolean. Controls IPv6 Router Advertisement (RA)
reception support for the interface. If true, RAs are accepted; if false, RAs
are ignored. When RAs are accepted, they may trigger the start of the DHCPv6
client if the relevant flags are set in the RA data, or if no routers are
found on the link. The default is to disable RA reception for bridge devices
or when IP forwarding is enabled, and to enable it otherwise. Cannot be
enabled on bond devices and when link local addressing is disabled.
Further settings for the IPv6 RA support may be configured in the
[IPv6AcceptRA] section, see below.
Also see ip-sysctl.txt[7] in the kernel documentation
regarding "accept_ra", but note that systemd's setting of 1
(i.e. true) corresponds to kernel's setting of 2.
Note that kernel's implementation of the IPv6 RA protocol is
always disabled, regardless of this setting. If this option is enabled, a
userspace implementation of the IPv6 RA protocol is used, and the kernel's
own implementation remains disabled, since systemd-networkd needs to
know all details supplied in the advertisements, and these are not available
from the kernel if the kernel's own implementation is used.
IPv6DuplicateAddressDetection=
Configures the amount of IPv6 Duplicate Address Detection
(DAD) probes to send. When unset, the kernel's default will be used.
IPv6HopLimit=
Configures IPv6 Hop Limit. For each router that forwards
the packet, the hop limit is decremented by 1. When the hop limit field
reaches zero, the packet is discarded. When unset, the kernel's default will
be used.
IPv4AcceptLocal=
Takes a boolean. Accept packets with local source
addresses. In combination with suitable routing, this can be used to direct
packets between two local interfaces over the wire and have them accepted
properly. When unset, the kernel's default will be used.
IPv4ProxyARP=
Takes a boolean. Configures proxy ARP for IPv4. Proxy ARP
is the technique in which one host, usually a router, answers ARP requests
intended for another machine. By "faking" its identity, the router
accepts responsibility for routing packets to the "real"
destination. See RFC 1027[9]. When unset, the kernel's default will be
used.
IPv6ProxyNDP=
Takes a boolean. Configures proxy NDP for IPv6. Proxy NDP
(Neighbor Discovery Protocol) is a technique for IPv6 to allow routing of
addresses to a different destination when peers expect them to be present on a
certain physical link. In this case a router answers Neighbour Advertisement
messages intended for another machine by offering its own MAC address as
destination. Unlike proxy ARP for IPv4, it is not enabled globally, but will
only send Neighbour Advertisement messages for addresses in the IPv6 neighbor
proxy table, which can also be shown by ip -6 neighbour show proxy.
systemd-networkd will control the per-interface `proxy_ndp` switch for each
configured interface depending on this option. When unset, the kernel's
default will be used.
IPv6ProxyNDPAddress=
An IPv6 address, for which Neighbour Advertisement
messages will be proxied. This option may be specified more than once.
systemd-networkd will add the IPv6ProxyNDPAddress= entries to the
kernel's IPv6 neighbor proxy table. This option implies
IPv6ProxyNDP=yes but has no effect if IPv6ProxyNDP has been set
to false. When unset, the kernel's default will be used.
IPv6SendRA=
Whether to enable or disable Router Advertisement sending
on a link. Takes a boolean value. When enabled, prefixes configured in
[IPv6Prefix] sections and routes configured in [IPv6RoutePrefix] sections are
distributed as defined in the [IPv6SendRA] section. If
DHCPv6PrefixDelegation= is enabled, then the delegated prefixes are
also distributed. See DHCPv6PrefixDelegation= setting and the
[IPv6SendRA], [IPv6Prefix], [IPv6RoutePrefix], and [DHCPv6PrefixDelegation]
sections for more configuration options.
DHCPv6PrefixDelegation=
Takes a boolean value. When enabled, requests prefixes
using a DHCPv6 client configured on another link. By default, an address
within each delegated prefix will be assigned, and the prefixes will be
announced through IPv6 Router Advertisement when IPv6SendRA= is
enabled. Such default settings can be configured in [DHCPv6PrefixDelegation]
section. Defaults to disabled.
IPv6MTUBytes=
Configures IPv6 maximum transmission unit (MTU). An
integer greater than or equal to 1280 bytes. When unset, the kernel's default
will be used.
Bridge=
Bond=
VRF=
VLAN=
The name of a VLAN to create on the link. See
systemd.netdev(5). This option may be specified more than once.
IPVLAN=
The name of a IPVLAN to create on the link. See
systemd.netdev(5). This option may be specified more than once.
MACVLAN=
The name of a MACVLAN to create on the link. See
systemd.netdev(5). This option may be specified more than once.
VXLAN=
The name of a VXLAN to create on the link. See
systemd.netdev(5). This option may be specified more than once.
Tunnel=
The name of a Tunnel to create on the link. See
systemd.netdev(5). This option may be specified more than once.
MACsec=
The name of a MACsec device to create on the link. See
systemd.netdev(5). This option may be specified more than once.
ActiveSlave=
Takes a boolean. Specifies the new active slave. The
"ActiveSlave=" option is only valid for following modes:
"active-backup", "balance-alb" and
"balance-tlb". Defaults to false.
PrimarySlave=
Takes a boolean. Specifies which slave is the primary
device. The specified device will always be the active slave while it is
available. Only when the primary is off-line will alternate devices be used.
This is useful when one slave is preferred over another, e.g. when one slave
has higher throughput than another. The "PrimarySlave=" option is
only valid for following modes: "active-backup",
"balance-alb" and "balance-tlb". Defaults to false.
ConfigureWithoutCarrier=
Takes a boolean. Allows networkd to configure a specific
link even if it has no carrier. Defaults to false. If
IgnoreCarrierLoss= is not explicitly set, it will default to this
value.
IgnoreCarrierLoss=
Takes a boolean. Allows networkd to retain both the
static and dynamic configuration of the interface even if its carrier is lost.
When unset, the value specified with ConfigureWithoutCarrier= is
used.
Xfrm=
The name of the xfrm to create on the link. See
systemd.netdev(5). This option may be specified more than once.
KeepConfiguration=
Takes a boolean or one of "static",
"dhcp-on-stop", "dhcp". When "static",
systemd-networkd will not drop static addresses and routes on starting
up process. When set to "dhcp-on-stop", systemd-networkd will
not drop addresses and routes on stopping the daemon. When "dhcp",
the addresses and routes provided by a DHCP server will never be dropped even
if the DHCP lease expires. This is contrary to the DHCP specification, but may
be the best choice if, e.g., the root filesystem relies on this connection.
The setting "dhcp" implies "dhcp-on-stop", and
"yes" implies "dhcp" and "static". Defaults to
"no".
An [Address] section accepts the following keys. Specify several
[Address] sections to configure several addresses.
Address=
As in the [Network] section. This key is mandatory. Each
[Address] section can contain one Address= setting.
Peer=
The peer address in a point-to-point connection. Accepts
the same format as the Address= key.
Broadcast=
The broadcast address, which must be in the format
described in
inet_pton(3). This key only applies to IPv4 addresses. If
it is not given, it is derived from the
Address= key.
Label=
An address label.
PreferredLifetime=
Allows the default "preferred lifetime" of the
address to be overridden. Only three settings are accepted:
"forever" or "infinity" which is the default and means
that the address never expires, and "0" 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.
Scope=
The scope of the address, which can be "global"
(valid everywhere on the network, even through a gateway), "link"
(only valid on this device, will not traverse a gateway) or "host"
(only valid within the device itself, e.g. 127.0.0.1) or an unsigned integer
in the range 0—255. Defaults to "global".
HomeAddress=
Takes a boolean. Designates this address the "home
address" as defined in RFC 6275[10]. Supported only on IPv6.
Defaults to false.
DuplicateAddressDetection=
Takes one of "ipv4", "ipv6",
"both", "none". When "ipv4", performs IPv4
Duplicate Address Detection. See RFC 5224[11]. When "ipv6",
performs IPv6 Duplicate Address Detection. See RFC 4862[12]. Defaults
to "ipv6".
ManageTemporaryAddress=
Takes a boolean. If true the kernel manage temporary
addresses created from this one as template on behalf of Privacy Extensions
RFC 3041[13]. For this to become active, the use_tempaddr sysctl
setting has to be set to a value greater than zero. The given address needs to
have a prefix length of 64. This flag allows using privacy extensions in a
manually configured network, just like if stateless auto-configuration was
active. Defaults to false.
AddPrefixRoute=
Takes a boolean. When true, the prefix route for the
address is automatically added. Defaults to true.
AutoJoin=
Takes a boolean. Joining multicast group on ethernet
level via ip maddr 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 ip link add vxlan 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 "autojoin" we can get
similar functionality for openvswitch (OVS) vxlan interfaces as well as other
tunneling mechanisms that need to receive multicast traffic. Defaults to
"no".
A [Neighbor] section accepts the following keys. The neighbor
section adds a permanent, static entry to the neighbor table (IPv6) or ARP
table (IPv4) for the given hardware address on the links matched for the
network. Specify several [Neighbor] sections to configure several static
neighbors.
Address=
The IP address of the neighbor.
LinkLayerAddress=
The link layer address (MAC address or IP address) of the
neighbor.
An [IPv6AddressLabel] section accepts the following keys. Specify
several [IPv6AddressLabel] sections to configure several address labels.
IPv6 address labels are used for address selection. See RFC 3484[14].
Precedence is managed by userspace, and only the label itself is stored in
the kernel.
Label=
The label for the prefix, an unsigned integer in the
range 0–4294967294. 0xffffffff is reserved. This setting is
mandatory.
Prefix=
IPv6 prefix is an address with a prefix length, separated
by a slash "/" character. This key is mandatory.
An [RoutingPolicyRule] section accepts the following keys. Specify
several [RoutingPolicyRule] sections to configure several rules.
TypeOfService=
Takes a number between 0 and 255 that specifies the type
of service to match.
From=
Specifies the source address prefix to match. Possibly
followed by a slash and the prefix length.
To=
Specifies the destination address prefix to match.
Possibly followed by a slash and the prefix length.
FirewallMark=
Specifies the iptables firewall mark value to match (a
number between 1 and 4294967295). Optionally, the firewall mask (also a number
between 1 and 4294967295) can be suffixed with a slash ("/"), e.g.,
"7/255".
Table=
Specifies the routing table identifier to lookup if the
rule selector matches. Takes one of "default", "main", and
"local", or a number between 1 and 4294967295. Defaults to
"main".
Priority=
Specifies the priority of this rule. Priority= is
an unsigned integer. Higher number means lower priority, and rules get
processed in order of increasing number.
IncomingInterface=
Specifies incoming device to match. If the interface is
loopback, the rule only matches packets originating from this host.
OutgoingInterface=
Specifies the outgoing device to match. The outgoing
interface is only available for packets originating from local sockets that
are bound to a device.
SourcePort=
Specifies the source IP port or IP port range match in
forwarding information base (FIB) rules. A port range is specified by the
lower and upper port separated by a dash. Defaults to unset.
DestinationPort=
Specifies the destination IP port or IP port range match
in forwarding information base (FIB) rules. A port range is specified by the
lower and upper port separated by a dash. Defaults to unset.
IPProtocol=
Specifies the IP protocol to match in forwarding
information base (FIB) rules. Takes IP protocol name such as "tcp",
"udp" or "sctp", or IP protocol number such as
"6" for "tcp" or "17" for "udp".
Defaults to unset.
InvertRule=
A boolean. Specifies whether the rule is to be inverted.
Defaults to false.
Family=
Takes a special value "ipv4", "ipv6",
or "both". By default, the address family is determined by the
address specified in To= or From=. If neither To= nor
From= are specified, then defaults to "ipv4".
User=
Takes a username, a user ID, or a range of user IDs
separated by a dash. Defaults to unset.
SuppressPrefixLength=
Takes a number N in the range 0-128 and rejects
routing decisions that have a prefix length of N or less. Defaults to
unset.
The [NextHop] section is used to manipulate entries in the
kernel's "nexthop" tables. The [NextHop] section accepts the
following keys. Specify several [NextHop] sections to configure several
hops.
Gateway=
As in the [Network] section. This is mandatory.
Id=
The id of the nexthop (an unsigned integer). If
unspecified or '0' then automatically chosen by kernel.
The [Route] section accepts the following keys. Specify several
[Route] sections to configure several routes.
Gateway=
Takes the gateway address or the special values
"_dhcp4" and "_ipv6ra". If "_dhcp4" or
"_ipv6ra" is set, then the gateway address provided by DHCPv4 or
IPv6 RA is used.
GatewayOnLink=
Takes a boolean. If set to true, the kernel does not have
to check if the gateway is reachable directly by the current machine (i.e.,
the kernel does not need to check if the gateway is attached to the local
network), so that we can insert the route in the kernel table without it being
complained about. Defaults to "no".
Destination=
The destination prefix of the route. Possibly followed by
a slash and the prefix length. If omitted, a full-length host route is
assumed.
Source=
The source prefix of the route. Possibly followed by a
slash and the prefix length. If omitted, a full-length host route is
assumed.
Metric=
The metric of the route (an unsigned integer).
IPv6Preference=
Specifies the route preference as defined in RFC
4191[15] for Router Discovery messages. Which can be one of
"low" the route has a lowest priority, "medium" the route
has a default priority or "high" the route has a highest
priority.
Scope=
The scope of the IPv4 route, which can be
"global", "site", "link", "host", or
"nowhere":
•"global" means the route can reach
hosts more than one hop away.
•"site" means an interior route in the
local autonomous system.
•"link" means the route can only reach
hosts on the local network (one hop away).
•"host" means the route will not leave
the local machine (used for internal addresses like 127.0.0.1).
•"nowhere" means the destination doesn't
exist.
For IPv4 route, defaults to "host" if Type= is
"local" or "nat", and "link" if Type=
is "broadcast", "multicast", or "anycast". In
other cases, defaults to "global". The value is not used for
IPv6.
PreferredSource=
The preferred source address of the route. The address
must be in the format described in
inet_pton(3).
Table=
The table identifier for the route. Takes
"default", "main", "local" or a number between 1
and 4294967295. The table can be retrieved using ip route show table
num. If unset and Type= is "local",
"broadcast", "anycast", or "nat", then
"local" is used. In other cases, defaults to "main".
Protocol=
The protocol identifier for the route. Takes a number
between 0 and 255 or the special values "kernel", "boot",
"static", "ra" and "dhcp". Defaults to
"static".
Type=
Specifies the type for the route. Takes one of
"unicast", "local", "broadcast",
"anycast", "multicast", "blackhole",
"unreachable", "prohibit", "throw",
"nat", and "xresolve". If "unicast", a regular
route is defined, i.e. a route indicating the path to take to a destination
network address. If "blackhole", packets to the defined route are
discarded silently. If "unreachable", packets to the defined route
are discarded and the ICMP message "Host Unreachable" is generated.
If "prohibit", packets to the defined route are discarded and the
ICMP message "Communication Administratively Prohibited" is
generated. If "throw", route lookup in the current routing table
will fail and the route selection process will return to Routing Policy
Database (RPDB). Defaults to "unicast".
InitialCongestionWindow=
The TCP initial congestion window is used during the
start of a TCP connection. During the start of a TCP session, when a client
requests a resource, the server's initial congestion window determines how
many packets will be sent during the initial burst of data without waiting for
acknowledgement. Takes a number between 1 and 1023. Note that 100 is
considered an extremely large value for this option. When unset, the kernel's
default (typically 10) will be used.
InitialAdvertisedReceiveWindow=
The TCP initial advertised receive window is the amount
of receive data (in bytes) that can initially be buffered at one time on a
connection. The sending host can send only that amount of data before waiting
for an acknowledgment and window update from the receiving host. Takes a
number between 1 and 1023. Note that 100 is considered an extremely large
value for this option. When unset, the kernel's default will be used.
QuickAck=
Takes a boolean. When true enables TCP quick ack mode for
the route. When unset, the kernel's default will be used.
FastOpenNoCookie=
Takes a boolean. When true enables TCP fastopen without a
cookie on a per-route basis. When unset, the kernel's default will be
used.
TTLPropagate=
Takes a boolean. When true enables TTL propagation at
Label Switched Path (LSP) egress. When unset, the kernel's default will be
used.
MTUBytes=
The maximum transmission unit in bytes to set for the
route. The usual suffixes K, M, G, are supported and are understood to the
base of 1024.
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.
IPServiceType=
Takes string; "CS6" or "CS4". Used to
set IP service type to CS6 (network control) or CS4 (Realtime). Defaults to
CS6.
MultiPathRoute=address[@name]
[weight]
Configures multipath route. Multipath routing is the
technique of using multiple alternative paths through a network. Takes gateway
address. Optionally, takes a network interface name or index separated with
"@", and a weight in 1..256 for this multipath route separated with
whitespace. This setting can be specified multiple times. If an empty string
is assigned, then the all previous assignments are cleared.
The [DHCPv4] section configures the DHCPv4 client, if it is
enabled with the DHCP= setting described above:
UseDNS=
When true (the default), the DNS servers received from
the DHCP server will be used and take precedence over any statically
configured ones.
This corresponds to the nameserver option in
resolv.conf(5).
RoutesToDNS=
When true, the routes to the DNS servers received from
the DHCP server will be configured. When UseDNS= is disabled, this
setting is ignored. Defaults to false.
UseNTP=
When true (the default), the NTP servers received from
the DHCP server will be used by systemd-timesyncd.service and take precedence
over any statically configured ones.
UseSIP=
When true (the default), the SIP servers received from
the DHCP server will be collected and made available to client programs.
UseMTU=
When true, the interface maximum transmission unit from
the DHCP server will be used on the current link. If MTUBytes= is set,
then this setting is ignored. Defaults to false.
Anonymize=
Takes a boolean. When true, the options sent to the DHCP
server will follow the
RFC 7844[16] (Anonymity Profiles for DHCP
Clients) to minimize disclosure of identifying information. Defaults to false.
This option should only be set to true when
MACAddressPolicy= is set to "random" (see
systemd.link(5)).
Note that this configuration will overwrite others. In concrete,
the following variables will be ignored: SendHostname=,
ClientIdentifier=, UseRoutes=, UseMTU=,
VendorClassIdentifier=, UseTimezone=.
With this option enabled DHCP requests will mimic those generated
by Microsoft Windows, in order to reduce the ability to fingerprint and
recognize installations. This means DHCP request sizes will grow and lease
data will be more comprehensive than normally, though most of the requested
data is not actually used.
SendHostname=
When true (the default), the machine's hostname will be
sent to the DHCP server. Note that the machine's hostname must consist only of
7-bit ASCII lower-case characters and no spaces or dots, and be formatted as a
valid DNS domain name. Otherwise, the hostname is not sent even if this is set
to true.
MUDURL=
When configured, the specified Manufacturer Usage
Description (MUD) URL will be sent to the DHCPv4 server. Takes a URL of length
up to 255 characters. A superficial verification that the string is a valid
URL will be performed. DHCPv4 clients are intended to have at most one MUD URL
associated with them. See
RFC 8520[17].
MUD is an embedded software standard defined by the IETF that
allows IoT device makers to advertise device specifications, including the
intended communication patterns for their device when it connects to the
network. The network can then use this to author a context-specific access
policy, so the device functions only within those parameters.
UseHostname=
When true (the default), the hostname received from the
DHCP server will be set as the transient hostname of the system.
Hostname=
Use this value for the hostname which is sent to the DHCP
server, instead of machine's hostname. Note that the specified hostname must
consist only of 7-bit ASCII lower-case characters and no spaces or dots, and
be formatted as a valid DNS domain name.
UseDomains=
Takes a boolean, or the special value "route".
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
Domains=
setting. If set to "route", 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
Domains= setting when the argument is
prefixed with "~". Defaults to false.
It is recommended to enable this option only on trusted networks,
as setting this affects resolution of all hostnames, in particular of
single-label names. It is generally safer to use the supplied domain only as
routing domain, rather than as search domain, in order to not have it affect
local resolution of single-label names.
When set to true, this setting corresponds to the domain
option in resolv.conf(5).
UseRoutes=
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".
UseGateway=
When true, the gateway will be requested from the DHCP
server and added to the routing table with a metric of 1024, and a scope of
"link". When unset, the value specified with UseRoutes= is
used.
UseTimezone=
When true, the timezone received from the DHCP server
will be set as timezone of the local system. Defaults to "no".
ClientIdentifier=
The DHCPv4 client identifier to use. Takes one of
"mac", "duid" or "duid-only". If set to
"mac", the MAC address of the link is used. If set to
"duid", an RFC4361-compliant Client ID, which is the combination of
IAID and DUID (see below), is used. If set to "duid-only", only DUID
is used, this may not be RFC compliant, but some setups may require to use
this. Defaults to "duid".
VendorClassIdentifier=
The vendor class identifier used to identify vendor type
and configuration.
UserClass=
A DHCPv4 client can use UserClass option to identify the
type or category of user or applications it represents. The information
contained in this option is a string that represents the user class of which
the client is a member. Each class sets an identifying string of information
to be used by the DHCP service to classify clients. Takes a
whitespace-separated list of strings.
MaxAttempts=
Specifies how many times the DHCPv4 client configuration
should be attempted. Takes a number or "infinity". Defaults to
"infinity". Note that the time between retries is increased
exponentially, so the network will not be overloaded even if this number is
high.
DUIDType=
Override the global
DUIDType setting for this
network. See
networkd.conf(5) for a description of possible
values.
DUIDRawData=
Override the global
DUIDRawData setting for this
network. See
networkd.conf(5) for a description of possible
values.
IAID=
The DHCP Identity Association Identifier (IAID) for the
interface, a 32-bit unsigned integer.
RequestBroadcast=
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.
RouteMetric=
Set the routing metric for routes specified by the DHCP
server. Defaults to 1024.
RouteTable=num
The table identifier for DHCP routes (a number between 1
and 4294967295, or 0 to unset). The table can be retrieved using
ip route
show table num.
When used in combination with VRF=, the VRF's routing table
is used when this parameter is not specified.
RouteMTUBytes=
Specifies the MTU for the DHCP routes. Please see the
[Route] section for further details.
ListenPort=
Allow setting custom port for the DHCP client to listen
on.
FallbackLeaseLifetimeSec=
Allows to set DHCPv4 lease lifetime when DHCPv4 server
does not send the lease lifetime. Takes one of "forever" or
"infinity" means that the address never expires. Defaults to
unset.
SendRelease=
When true, the DHCPv4 client sends a DHCP release packet
when it stops. Defaults to true.
SendDecline=
A boolean. When "true", the DHCPv4 client
receives the IP address from the DHCP server. After a new IP is received, the
DHCPv4 client performs IPv4 Duplicate Address Detection. If duplicate use is
detected, the DHCPv4 client rejects the IP by sending a DHCPDECLINE packet and
tries to obtain an IP address again. See RFC 5224[11]. Defaults to
"unset".
DenyList=
A whitespace-separated list of IPv4 addresses. DHCP
offers from servers in the list are rejected. Note that if AllowList=
is configured then DenyList= is ignored.
AllowList=
A whitespace-separated list of IPv4 addresses. DHCP
offers from servers in the list are accepted.
RequestOptions=
When configured, allows to set arbitrary request options
in the DHCPv4 request options list and will be sent to the DHCPV4 server. A
whitespace-separated list of integers in the range 1..254. Defaults to
unset.
SendOption=
Send an arbitrary raw option in the DHCPv4 request. Takes
a DHCP option number, data type and data separated with a colon
("option:type:value"). The option number must
be an integer in the range 1..254. The type takes one of "uint8",
"uint16", "uint32", "ipv4address", or
"string". Special characters in the data string may be escaped using
C-style escapes[18]. This setting can be specified multiple times. If
an empty string is specified, then all options specified earlier are cleared.
Defaults to unset.
SendVendorOption=
Send an arbitrary vendor option in the DHCPv4 request.
Takes a DHCP option number, data type and data separated with a colon
("option:type:value"). The option number must
be an integer in the range 1..254. The type takes one of "uint8",
"uint16", "uint32", "ipv4address", or
"string". Special characters in the data string may be escaped using
C-style escapes[18]. This setting can be specified multiple times. If
an empty string is specified, then all options specified earlier are cleared.
Defaults to unset.
The [DHCPv6] section configures the DHCPv6 client, if it is
enabled with the DHCP= setting described above, or invoked by the
IPv6 Router Advertisement:
UseDNS=, UseNTP=
As in the [DHCPv4] section.
RouteMetric=
Set the routing metric for routes specified by the DHCP
server. Defaults to 1024.
RapidCommit=
Takes a boolean. The DHCPv6 client can obtain
configuration parameters from a DHCPv6 server through a rapid two-message
exchange (solicit and reply). When the rapid commit option is enabled by both
the DHCPv6 client and the DHCPv6 server, the two-message exchange is used,
rather than the default four-message exchange (solicit, advertise, request,
and reply). The two-message exchange provides faster client configuration and
is beneficial in environments in which networks are under a heavy load. See
RFC 3315[19] for details. Defaults to true.
MUDURL=
When configured, the specified Manufacturer Usage
Description (MUD) URL will be sent to the DHCPV6 server. The syntax and
semantics are the same as for MUDURL= in the [DHCPv4] section described
above.
RequestOptions=
When configured, allows to set arbitrary request options
in the DHCPv6 request options list that will be sent to the DHCPV6 server. A
whitespace-separated list of integers in the range 1..254. Defaults to
unset.
SendVendorOption=
Send an arbitrary vendor option in the DHCPv6 request.
Takes an enterprise identifier, DHCP option number, data type, and data
separated with a colon ("enterprise
identifier:option:type: value"). Enterprise
identifier is an unsigned integer in the range 1–4294967294. The option
number must be an integer in the range 1–254. Data type takes one of
"uint8", "uint16", "uint32",
"ipv4address", "ipv6address", or "string".
Special characters in the data string may be escaped using C-style
escapes[18]. This setting can be specified multiple times. If an empty
string is specified, then all options specified earlier are cleared. Defaults
to unset.
ForceDHCPv6PDOtherInformation=
Takes a boolean that enforces DHCPv6 stateful mode when
the 'Other information' bit is set in Router Advertisement messages. By
default setting only the 'O' bit in Router Advertisements makes DHCPv6 request
network information in a stateless manner using a two-message Information
Request and Information Reply message exchange. RFC 7084[20],
requirement WPD-4, updates this behavior for a Customer Edge router so that
stateful DHCPv6 Prefix Delegation is also requested when only the 'O' bit is
set in Router Advertisements. This option enables such a CE behavior as it is
impossible to automatically distinguish the intention of the 'O' bit
otherwise. By default this option is set to 'false', enable it if no prefixes
are delegated when the device should be acting as a CE router.
PrefixDelegationHint=
Takes an IPv6 address with prefix length in the same
format as the Address= in the [Network] section. The DHCPv6 client will
include a prefix hint in the DHCPv6 solicitation sent to the server. The
prefix length must be in the range 1–128. Defaults to unset.
WithoutRA=
Allows DHCPv6 client to start without router
advertisements's managed or other address configuration flag. Takes one of
"solicit" or "information-request". Defaults to
unset.
SendOption=
As in the [DHCPv4] section, however because DHCPv6 uses
16-bit fields to store option numbers, the option number is an integer in the
range 1..65536.
UserClass=
A DHCPv6 client can use User Class option to identify the
type or category of user or applications it represents. The information
contained in this option is a string that represents the user class of which
the client is a member. Each class sets an identifying string of information
to be used by the DHCP service to classify clients. Special characters in the
data string may be escaped using C-style escapes[18]. This setting can
be specified multiple times. If an empty string is specified, then all options
specified earlier are cleared. Takes a whitespace-separated list of strings.
Note that currently NUL bytes are not allowed.
VendorClass=
A DHCPv6 client can use VendorClass option to identify
the vendor that manufactured the hardware on which the client is running. The
information contained in the data area of this option is contained in one or
more opaque fields that identify details of the hardware configuration. Takes
a whitespace-separated list of strings.
The [DHCPv6PrefixDelegation] section configures delegated prefixes
assigned by DHCPv6 server. The settings in this section are used only when
DHCPv6PrefixDelegation= setting is enabled.
SubnetId=
Configure a specific subnet ID on the interface from a
(previously) received prefix delegation. You can either set "auto"
(the default) or a specific subnet ID (as defined in RFC 4291[21],
section 2.5.4), in which case the allowed value is hexadecimal, from 0 to
0x7fffffffffffffff inclusive.
Announce=
Takes a boolean. When enabled, and IPv6SendRA= in
[Network] section is enabled, the delegated prefixes are distributed through
the IPv6 Router Advertisement. Defaults to yes.
Assign=
Takes a boolean. Specifies whether to add an address from
the delegated prefixes which are received from the WAN interface by the DHCPv6
Prefix Delegation. When true (on LAN interfce), the EUI-64 algorithm will be
used by default to form an interface identifier from the delegated prefixes.
See also Token= setting below. Defaults to yes.
Token=
Specifies an optional address generation mode for
assigning an address in each delegated prefix. Takes an IPv6 address. When
set, the lower bits of the supplied address is combined with the upper bits of
each delegatad prefix received from the WAN interface by the DHCPv6 Prefix
Delegation to form a complete address. When Assign= is disabled, this
setting is ignored. When unset, the EUI-64 algorithm will be used to form
addresses. Defaults to unset.
The [IPv6AcceptRA] section configures the IPv6 Router
Advertisement (RA) client, if it is enabled with the IPv6AcceptRA=
setting described above:
UseDNS=
When true (the default), the DNS servers received in the
Router Advertisement will be used and take precedence over any statically
configured ones.
This corresponds to the nameserver option in
resolv.conf(5).
UseDomains=
Takes a boolean, or the special value "route".
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
Domains= setting. If set to "route", 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
Domains= setting when the argument is
prefixed with "~". Defaults to false.
It is recommended to enable this option only on trusted networks,
as setting this affects resolution of all hostnames, in particular of
single-label names. It is generally safer to use the supplied domain only as
routing domain, rather than as search domain, in order to not have it affect
local resolution of single-label names.
When set to true, this setting corresponds to the domain
option in resolv.conf(5).
RouteTable=num
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 ip route show table
num.
UseAutonomousPrefix=
When true (the default), the autonomous prefix received
in the Router Advertisement will be used and take precedence over any
statically configured ones.
UseOnLinkPrefix=
When true (the default), the onlink prefix received in
the Router Advertisement will be used and takes precedence over any statically
configured ones.
DenyList=
A whitespace-separated list of IPv6 prefixes. IPv6
prefixes supplied via router advertisements in the list are ignored.
DHCPv6Client=
Takes a boolean, or the special value "always".
When true or "always", the DHCPv6 client will be started when the RA
has the managed or other information flag. If set to "always", the
DHCPv6 client will also be started in managed mode when neither managed nor
other information flag is set in the RA. Defaults to true.
The [DHCPServer] section contains settings for the DHCP server, if
enabled via the DHCPServer= option described above:
PoolOffset=, PoolSize=
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.
PoolOffset= takes the offset of the pool from the start of subnet, or
zero to use the default value. PoolSize= 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.
DefaultLeaseTimeSec=, MaxLeaseTimeSec=
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.
EmitDNS=, DNS=
EmitDNS= takes a boolean. Configures whether the
DHCP leases handed out to clients shall contain DNS server information.
Defaults to "yes". The DNS servers to pass to clients may be
configured with the DNS= option, which takes a list of IPv4 addresses.
If the EmitDNS= option is enabled but no servers configured, the
servers are automatically propagated from an "uplink" interface that
has appropriate servers set. The "uplink" interface is determined by
the default route of the system with the highest priority. Note that this
information is acquired at the time the lease is handed out, and does not take
uplink interfaces into account that acquire DNS server information at a later
point. If no suitable uplinkg interface is found the DNS server data from
/etc/resolv.conf is used. Also, note that the leases are not refreshed if the
uplink network configuration changes. To ensure clients regularly acquire the
most current uplink DNS server information, it is thus advisable to shorten
the DHCP lease time via MaxLeaseTimeSec= described above.
EmitNTP=, NTP=, EmitSIP=, SIP=,
EmitPOP3=, POP3=, EmitSMTP=, SMTP=,
EmitLPR=, LPR=
Similar to the EmitDNS= and DNS= settings
described above, these settings configure whether and what server information
for the indicate protocol shall be emitted as part of the DHCP lease. The same
syntax, propagation semantics and defaults apply as for EmitDNS= and
DNS=.
EmitRouter=
Similar to the EmitDNS= 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
EmitDNS=.
EmitTimezone=, Timezone=
Takes a boolean. Configures whether the DHCP leases
handed out to clients shall contain timezone information. Defaults to
"yes". The Timezone= setting takes a timezone string (such as
"Europe/Berlin" or "UTC") to pass to clients. If no
explicit timezone is set, the system timezone of the local host is propagated,
as determined by the /etc/localtime symlink.
SendOption=
Send a raw option with value via DHCPv4 server. Takes a
DHCP option number, data type and data
("option:type:value"). The option number is an
integer in the range 1..254. The type takes one of "uint8",
"uint16", "uint32", "ipv4address",
"ipv6address", or "string". Special characters in the data
string may be escaped using C-style escapes[18]. This setting can be
specified multiple times. If an empty string is specified, then all options
specified earlier are cleared. Defaults to unset.
SendVendorOption=
Send a vendor option with value via DHCPv4 server. Takes
a DHCP option number, data type and data
("option:type:value"). The option number is an
integer in the range 1..254. The type takes one of "uint8",
"uint16", "uint32", "ipv4address", or
"string". Special characters in the data string may be escaped using
C-style escapes[18]. This setting can be specified multiple times. If
an empty string is specified, then all options specified earlier are cleared.
Defaults to unset.
The [IPv6SendRA] section contains settings for sending IPv6 Router
Advertisements and whether to act as a router, if enabled via the
IPv6SendRA= option described above. IPv6 network prefixes or routes
are defined with one or more [IPv6Prefix] or [IPv6RoutePrefix] sections.
Managed=, OtherInformation=
Takes a boolean. Controls whether a DHCPv6 server is used
to acquire IPv6 addresses on the network link when Managed= is set to
"true" or if only additional network information can be obtained via
DHCPv6 for the network link when OtherInformation= is set to
"true". Both settings default to "false", which means that
a DHCPv6 server is not being used.
RouterLifetimeSec=
Takes a timespan. Configures the IPv6 router lifetime in
seconds. When set to 0, the host is not acting as a router. Defaults to 30
minutes.
RouterPreference=
Configures IPv6 router preference if
RouterLifetimeSec= is non-zero. Valid values are "high",
"medium" and "low", with "normal" and
"default" added as synonyms for "medium" just to make
configuration easier. See RFC 4191[15] for details. Defaults to
"medium".
EmitDNS=, DNS=
DNS= specifies a list of recursive DNS server IPv6
addresses that are distributed via Router Advertisement messages when
EmitDNS= is true. DNS= also takes special value
"_link_local"; in that case the IPv6 link local address is
distributed. If DNS= is empty, DNS servers are read from the [Network]
section. If the [Network] section does not contain any DNS servers either, DNS
servers from the uplink with the highest priority default route are used. When
EmitDNS= is false, no DNS server information is sent in Router
Advertisement messages. EmitDNS= defaults to true.
EmitDomains=, Domains=
A list of DNS search domains distributed via Router
Advertisement messages when EmitDomains= is true. If Domains= is
empty, DNS search domains are read from the [Network] section. If the
[Network] section does not contain any DNS search domains either, DNS search
domains from the uplink with the highest priority default route are used. When
EmitDomains= is false, no DNS search domain information is sent in
Router Advertisement messages. EmitDomains= defaults to true.
DNSLifetimeSec=
Lifetime in seconds for the DNS server addresses listed
in DNS= and search domains listed in Domains=.
One or more [IPv6Prefix] sections contain the IPv6 prefixes that
are announced via Router Advertisements. See RFC 4861[22] for further
details.
AddressAutoconfiguration=, OnLink=
Takes a boolean to specify whether IPv6 addresses can be
autoconfigured with this prefix and whether the prefix can be used for onlink
determination. Both settings default to "true" in order to ease
configuration.
Prefix=
The IPv6 prefix that is to be distributed to hosts.
Similarly to configuring static IPv6 addresses, the setting is configured as
an IPv6 prefix and its prefix length, separated by a "/" character.
Use multiple [IPv6Prefix] sections to configure multiple IPv6 prefixes since
prefix lifetimes, address autoconfiguration and onlink status may differ from
one prefix to another.
PreferredLifetimeSec=, ValidLifetimeSec=
Preferred and valid lifetimes for the prefix measured in
seconds. PreferredLifetimeSec= defaults to 604800 seconds (one week)
and ValidLifetimeSec= defaults to 2592000 seconds (30 days).
Assign=
Takes a boolean. When true, adds an address from the
prefix. Default to false.
One or more [IPv6RoutePrefix] sections contain the IPv6 prefix
routes that are announced via Router Advertisements. See RFC 4191[15]
for further details.
Route=
The IPv6 route that is to be distributed to hosts.
Similarly to configuring static IPv6 routes, the setting is configured as an
IPv6 prefix routes and its prefix route length, separated by a "/"
character. Use multiple [IPv6PrefixRoutes] sections to configure multiple IPv6
prefix routes.
LifetimeSec=
Lifetime for the route prefix measured in seconds.
LifetimeSec= defaults to 604800 seconds (one week).
The [Bridge] section accepts the following keys:
UnicastFlood=
Takes a boolean. Controls whether the bridge should flood
traffic for which an FDB entry is missing and the destination is unknown
through this port. When unset, the kernel's default will be used.
MulticastFlood=
Takes a boolean. Controls whether the bridge should flood
traffic for which an MDB entry is missing and the destination is unknown
through this port. When unset, the kernel's default will be used.
MulticastToUnicast=
Takes a boolean. Multicast to unicast works on top of the
multicast snooping feature of the bridge. Which means unicast copies are only
delivered to hosts which are interested in it. When unset, the kernel's
default will be used.
NeighborSuppression=
Takes a boolean. Configures whether ARP and ND neighbor
suppression is enabled for this port. When unset, the kernel's default will be
used.
Learning=
Takes a boolean. Configures whether MAC address learning
is enabled for this port. When unset, the kernel's default will be used.
HairPin=
Takes a boolean. Configures whether traffic may be sent
back out of the port on which it was received. When this flag is false, then
the bridge will not forward traffic back out of the receiving port. When
unset, the kernel's default will be used.
UseBPDU=
Takes a boolean. Configures whether STP Bridge Protocol
Data Units will be processed by the bridge port. When unset, the kernel's
default will be used.
FastLeave=
Takes a boolean. This flag allows the bridge to
immediately stop multicast traffic on a port that receives an IGMP Leave
message. It is only used with IGMP snooping if enabled on the bridge. When
unset, the kernel's default will be used.
AllowPortToBeRoot=
Takes a boolean. Configures whether a given port is
allowed to become a root port. Only used when STP is enabled on the bridge.
When unset, the kernel's default will be used.
ProxyARP=
Takes a boolean. Configures whether proxy ARP to be
enabled on this port. When unset, the kernel's default will be used.
ProxyARPWiFi=
Takes a boolean. Configures whether proxy ARP to be
enabled on this port which meets extended requirements by IEEE 802.11 and
Hotspot 2.0 specifications. When unset, the kernel's default will be
used.
MulticastRouter=
Configures this port for having multicast routers
attached. A port with a multicast router will receive all multicast traffic.
Takes one of "no" to disable multicast routers on this port,
"query" to let the system detect the presence of routers,
"permanent" to permanently enable multicast traffic forwarding on
this port, or "temporary" to enable multicast routers temporarily on
this port, not depending on incoming queries. When unset, the kernel's default
will be used.
Cost=
Sets the "cost" of sending packets of this
interface. Each port in a bridge may have a different speed and the cost is
used to decide which link to use. Faster interfaces should have lower costs.
It is an integer value between 1 and 65535.
Priority=
Sets the "priority" of sending packets on this
interface. Each port in a bridge may have a different priority which is used
to decide which link to use. Lower value means higher priority. It is an
integer value between 0 to 63. Networkd does not set any default, meaning the
kernel default value of 32 is used.
The [BridgeFDB] section manages the forwarding database table of a
port and accepts the following keys. Specify several [BridgeFDB] sections to
configure several static MAC table entries.
MACAddress=
As in the [Network] section. This key is mandatory.
Destination=
Takes an IP address of the destination VXLAN tunnel
endpoint.
VLANId=
The VLAN ID for the new static MAC table entry. If
omitted, no VLAN ID information is appended to the new static MAC table
entry.
VNI=
The VXLAN Network Identifier (or VXLAN Segment ID) to use
to connect to the remote VXLAN tunnel endpoint. Takes a number in the range
1-16777215. Defaults to unset.
AssociatedWith=
Specifies where the address is associated with. Takes one
of "use", "self", "master" or
"router". "use" means the address is in use. User space
can use this option to indicate to the kernel that the fdb entry is in use.
"self" means the address is associated with the port drivers fdb.
Usually hardware. "master" means the address is associated with
master devices fdb. "router" means the destination address is
associated with a router. Note that it's valid if the referenced device is a
VXLAN type device and has route shortcircuit enabled. Defaults to
"self".
The [BridgeMDB] section manages the multicast membership entries
forwarding database table of a port and accepts the following keys. Specify
several [BridgeMDB] sections to configure several permanent multicast
membership entries.
MulticastGroupAddress=
Specifies the IPv4 or IPv6 multicast group address to
add. This setting is mandatory.
VLANId=
The VLAN ID for the new entry. Valid ranges are 0 (no
VLAN) to 4094. Optional, defaults to 0.
The [LLDP] section manages the Link Layer Discovery Protocol
(LLDP) and accepts the following keys:
MUDURL=
When configured, the specified Manufacturer Usage
Descriptions (MUD) URL will be sent in LLDP packets. The syntax and semantics
are the same as for
MUDURL= in the [DHCPv4] section described above.
The MUD URLs received via LLDP packets are saved and can be read
using the sd_lldp_neighbor_get_mud_url() function.
The [CAN] section manages the Controller Area Network (CAN bus)
and accepts the following keys:
BitRate=
The bitrate of CAN device in bits per second. The usual
SI prefixes (K, M) with the base of 1000 can be used here. Takes a number in
the range 1..4294967295.
SamplePoint=
Optional sample point in percent with one decimal (e.g.
"75%", "87.5%") or permille (e.g.
"875‰").
DataBitRate=, DataSamplePoint=
The bitrate and sample point for the data phase, if
CAN-FD is used. These settings are analogous to the BitRate= and
SamplePoint= keys.
FDMode=
Takes a boolean. When "yes", CAN-FD mode is
enabled for the interface. Note, that a bitrate and optional sample point
should also be set for the CAN-FD data phase using the DataBitRate= and
DataSamplePoint= keys.
FDNonISO=
Takes a boolean. When "yes", non-ISO CAN-FD
mode is enabled for the interface. When unset, the kernel's default will be
used.
RestartSec=
Automatic restart delay time. If set to a non-zero value,
a restart of the CAN controller will be triggered automatically in case of a
bus-off condition after the specified delay time. Subsecond delays can be
specified using decimals (e.g. "0.1s") or a "ms" or
"us" postfix. Using "infinity" or "0" will turn
the automatic restart off. By default automatic restart is disabled.
Termination=
Takes a boolean. When "yes", the termination
resistor will be selected for the bias network. When unset, the kernel's
default will be used.
TripleSampling=
Takes a boolean. When "yes", three samples
(instead of one) are used to determine the value of a received bit by majority
rule. When unset, the kernel's default will be used.
ListenOnly=
Takes a boolean. When "yes", listen-only mode
is enabled. When the interface is in listen-only mode, the interface neither
transmit CAN frames nor send ACK bit. Listen-only mode is important to debug
CAN networks without interfering with the communication or acknowledge the CAN
frame. When unset, the kernel's default will be used.
The [QDisc] section manages the traffic control queueing
discipline (qdisc).
Parent=
Specifies the parent Queueing Discipline (qdisc). Takes
one of "clsact" or "ingress". This is mandatory.
Handle=
Configures the major number of unique identifier of the
qdisc, known as the handle. Takes a hexadecimal number in the range
0x1–0xffff. Defaults to unset.
The [NetworkEmulator] section manages the queueing discipline
(qdisc) of the network emulator. It can be used to configure the kernel
packet scheduler and simulate packet delay and loss for UDP or TCP
applications, or limit the bandwidth usage of a particular service to
simulate internet connections.
Parent=
Configures the parent Queueing Discipline (qdisc). Takes
one of "root", "clsact", "ingress" or a class
identifier. The class identifier is specified as the major and minor numbers
in hexadecimal in the range 0x1–Oxffff separated with a colon
("major:minor"). Defaults to "root".
Handle=
Configures the major number of unique identifier of the
qdisc, known as the handle. Takes a hexadecimal number in the range
0x1–0xffff. Defaults to unset.
DelaySec=
Specifies the fixed amount of delay to be added to all
packets going out of the interface. Defaults to unset.
DelayJitterSec=
Specifies the chosen delay to be added to the packets
outgoing to the network interface. Defaults to unset.
PacketLimit=
Specifies the maximum number of packets the qdisc may
hold queued at a time. An unsigned integer in the range 0–4294967294.
Defaults to 1000.
LossRate=
Specifies an independent loss probability to be added to
the packets outgoing from the network interface. Takes a percentage value,
suffixed with "%". Defaults to unset.
DuplicateRate=
Specifies that the chosen percent of packets is
duplicated before queuing them. Takes a percentage value, suffixed with
"%". Defaults to unset.
The [TokenBucketFilter] section manages the queueing discipline
(qdisc) of token bucket filter (tbf).
Parent=
Configures the parent Queueing Discipline (qdisc). Takes
one of "root", "clsact", "ingress" or a class
identifier. The class identifier is specified as the major and minor numbers
in hexadecimal in the range 0x1–Oxffff separated with a colon
("major:minor"). Defaults to "root".
Handle=
Configures the major number of unique identifier of the
qdisc, known as the handle. Takes a hexadecimal number in the range
0x1–0xffff. Defaults to unset.
LatencySec=
Specifies the latency parameter, which specifies the
maximum amount of time a packet can sit in the Token Bucket Filter (TBF).
Defaults to unset.
LimitBytes=
Takes the number of bytes that can be queued waiting for
tokens to become available. When the size is suffixed with K, M, or G, it is
parsed as Kilobytes, Megabytes, or Gigabytes, respectively, to the base of
1024. Defaults to unset.
BurstBytes=
Specifies the size of the bucket. This is the maximum
amount of bytes that tokens can be available for instantaneous transfer. When
the size is suffixed with K, M, or G, it is parsed as Kilobytes, Megabytes, or
Gigabytes, respectively, to the base of 1024. Defaults to unset.
Rate=
Specifies the device specific bandwidth. When suffixed
with K, M, or G, the specified bandwidth is parsed as Kilobits, Megabits, or
Gigabits, respectively, to the base of 1000. Defaults to unset.
MPUBytes=
The Minimum Packet Unit (MPU) determines the minimal
token usage (specified in bytes) for a packet. When suffixed with K, M, or G,
the specified size is parsed as Kilobytes, Megabytes, or Gigabytes,
respectively, to the base of 1024. Defaults to zero.
PeakRate=
Takes the maximum depletion rate of the bucket. When
suffixed with K, M, or G, the specified size is parsed as Kilobits, Megabits,
or Gigabits, respectively, to the base of 1000. Defaults to unset.
MTUBytes=
Specifies the size of the peakrate bucket. When suffixed
with K, M, or G, the specified size is parsed as Kilobytes, Megabytes, or
Gigabytes, respectively, to the base of 1024. Defaults to unset.
The [PIE] section manages the queueing discipline (qdisc) of
Proportional Integral controller-Enhanced (PIE).
Parent=
Configures the parent Queueing Discipline (qdisc). Takes
one of "root", "clsact", "ingress" or a class
identifier. The class identifier is specified as the major and minor numbers
in hexadecimal in the range 0x1–Oxffff separated with a colon
("major:minor"). Defaults to "root".
Handle=
Configures the major number of unique identifier of the
qdisc, known as the handle. Takes a hexadecimal number in the range
0x1–0xffff. Defaults to unset.
PacketLimit=
Specifies the hard limit on the queue size in number of
packets. When this limit is reached, incoming packets are dropped. An unsigned
integer in the range 1–4294967294. Defaults to unset and kernel's
default is used.
The "[FlowQueuePIE]" section manages the queueing
discipline (qdisc) of Flow Queue Proportional Integral controller-Enhanced
(fq_pie).
Parent=
Configures the parent Queueing Discipline (qdisc). Takes
one of "root", "clsact", "ingress" or a class
identifier. The class identifier is specified as the major and minor numbers
in hexadecimal in the range 0x1–Oxffff separated with a colon
("major:minor"). Defaults to "root".
Handle=
Configures the major number of unique identifier of the
qdisc, known as the handle. Takes a hexadecimal number in the range
0x1–0xffff. Defaults to unset.
PacketLimit=
Specifies the hard limit on the queue size in number of
packets. When this limit is reached, incoming packets are dropped. An unsigned
integer ranges 1 to 4294967294. Defaults to unset and kernel's default is
used.
The [StochasticFairBlue] section manages the queueing discipline
(qdisc) of stochastic fair blue (sfb).
Parent=
Configures the parent Queueing Discipline (qdisc). Takes
one of "root", "clsact", "ingress" or a class
identifier. The class identifier is specified as the major and minor numbers
in hexadecimal in the range 0x1–Oxffff separated with a colon
("major:minor"). Defaults to "root".
Handle=
Configures the major number of unique identifier of the
qdisc, known as the handle. Takes a hexadecimal number in the range
0x1–0xffff. Defaults to unset.
PacketLimit=
Specifies the hard limit on the queue size in number of
packets. When this limit is reached, incoming packets are dropped. An unsigned
integer in the range 0–4294967294. Defaults to unset and kernel's
default is used.
The [StochasticFairnessQueueing] section manages the queueing
discipline (qdisc) of stochastic fairness queueing (sfq).
Parent=
Configures the parent Queueing Discipline (qdisc). Takes
one of "root", "clsact", "ingress" or a class
identifier. The class identifier is specified as the major and minor numbers
in hexadecimal in the range 0x1–Oxffff separated with a colon
("major:minor"). Defaults to "root".
Handle=
Configures the major number of unique identifier of the
qdisc, known as the handle. Takes a hexadecimal number in the range
0x1–0xffff. Defaults to unset.
PerturbPeriodSec=
Specifies the interval in seconds for queue algorithm
perturbation. Defaults to unset.
The [BFIFO] section manages the queueing discipline (qdisc) of
Byte limited Packet First In First Out (bfifo).
Parent=
Configures the parent Queueing Discipline (qdisc). Takes
one of "root", "clsact", "ingress" or a class
identifier. The class identifier is specified as the major and minor numbers
in hexadecimal in the range 0x1–Oxffff separated with a colon
("major:minor"). Defaults to "root".
Handle=
Configures the major number of unique identifier of the
qdisc, known as the handle. Takes a hexadecimal number in the range
0x1–0xffff. Defaults to unset.
LimitBytes=
Specifies the hard limit in bytes on the FIFO buffer
size. The size limit prevents overflow in case the kernel is unable to dequeue
packets as quickly as it receives them. When this limit is reached, incoming
packets are dropped. When suffixed with K, M, or G, the specified size is
parsed as Kilobytes, Megabytes, or Gigabytes, respectively, to the base of
1024. Defaults to unset and kernel default is used.
The [PFIFO] section manages the queueing discipline (qdisc) of
Packet First In First Out (pfifo).
Parent=
Configures the parent Queueing Discipline (qdisc). Takes
one of "root", "clsact", "ingress" or a class
identifier. The class identifier is specified as the major and minor numbers
in hexadecimal in the range 0x1–Oxffff separated with a colon
("major:minor"). Defaults to "root".
Handle=
Configures the major number of unique identifier of the
qdisc, known as the handle. Takes a hexadecimal number in the range
0x1–0xffff. Defaults to unset.
PacketLimit=
Specifies the hard limit on the FIFO size in number of
packets. The size limit (a buffer size) to prevent it from overflowing in case
it is unable to dequeue packets as quickly as it receives them. When this
limit is reached, incoming packets are dropped. An unsigned integer in the
range 0–4294967294. Defaults to unset and kernel's default is
used.
The [PFIFOHeadDrop] section manages the queueing discipline
(qdisc) of Packet First In First Out Head Drop (pfifo_head_drop).
Parent=
Configures the parent Queueing Discipline (qdisc). Takes
one of "root", "clsact", "ingress" or a class
identifier. The class identifier is specified as the major and minor numbers
in hexadecimal in the range 0x1–Oxffff separated with a colon
("major:minor"). Defaults to "root".
Handle=
Configures the major number of unique identifier of the
qdisc, known as the handle. Takes a hexadecimal number in the range
0x1–0xffff. Defaults to unset.
PacketLimit=
As in [PFIFO] section.
The [PFIFOFast] section manages the queueing discipline (qdisc) of
Packet First In First Out Fast (pfifo_fast).
Parent=
Configures the parent Queueing Discipline (qdisc). Takes
one of "root", "clsact", "ingress" or a class
identifier. The class identifier is specified as the major and minor numbers
in hexadecimal in the range 0x1–Oxffff separated with a colon
("major:minor"). Defaults to "root".
Handle=
Configures the major number of unique identifier of the
qdisc, known as the handle. Takes a hexadecimal number in the range
0x1–0xffff. Defaults to unset.
The [CAKE] section manages the queueing discipline (qdisc) of
Common Applications Kept Enhanced (CAKE).
Parent=
Configures the parent Queueing Discipline (qdisc). Takes
one of "root", "clsact", "ingress" or a class
identifier. The class identifier is specified as the major and minor numbers
in hexadecimal in the range 0x1–Oxffff separated with a colon
("major:minor"). Defaults to "root".
Handle=
Configures the major number of unique identifier of the
qdisc, known as the handle. Takes a hexadecimal number in the range
0x1–0xffff. Defaults to unset.
OverheadBytes=
Specifies that bytes to be addeded to the size of each
packet. Bytes may be negative. Takes an integer in the range from -64 to 256.
Defaults to unset and kernel's default is used.
Bandwidth=
Specifies the shaper bandwidth. When suffixed with K, M,
or G, the specified size is parsed as Kilobits, Megabits, or Gigabits,
respectively, to the base of 1000. Defaults to unset and kernel's default is
used.
The [ControlledDelay] section manages the queueing discipline
(qdisc) of controlled delay (CoDel).
Parent=
Configures the parent Queueing Discipline (qdisc). Takes
one of "root", "clsact", "ingress" or a class
identifier. The class identifier is specified as the major and minor numbers
in hexadecimal in the range 0x1–Oxffff separated with a colon
("major:minor"). Defaults to "root".
Handle=
Configures the major number of unique identifier of the
qdisc, known as the handle. Takes a hexadecimal number in the range
0x1–0xffff. Defaults to unset.
PacketLimit=
Specifies the hard limit on the queue size in number of
packets. When this limit is reached, incoming packets are dropped. An unsigned
integer in the range 0–4294967294. Defaults to unset and kernel's
default is used.
TargetSec=
Takes a timespan. Specifies the acceptable minimum
standing/persistent queue delay. Defaults to unset and kernel's default is
used.
IntervalSec=
Takes a timespan. This is used to ensure that the
measured minimum delay does not become too stale. Defaults to unset and
kernel's default is used.
ECN=
Takes a boolean. This can be used to mark packets instead
of dropping them. Defaults to unset and kernel's default is used.
CEThresholdSec=
Takes a timespan. This sets a threshold above which all
packets are marked with ECN Congestion Experienced (CE). Defaults to unset and
kernel's default is used.
The [DeficitRoundRobinScheduler] section manages the queueing
discipline (qdisc) of Deficit Round Robin Scheduler (DRR).
Parent=
Configures the parent Queueing Discipline (qdisc). Takes
one of "root", "clsact", "ingress" or a class
identifier. The class identifier is specified as the major and minor numbers
in hexadecimal in the range 0x1–Oxffff separated with a colon
("major:minor"). Defaults to "root".
Handle=
Configures the major number of unique identifier of the
qdisc, known as the handle. Takes a hexadecimal number in the range
0x1–0xffff. Defaults to unset.
The [DeficitRoundRobinSchedulerClass] section manages the traffic
control class of Deficit Round Robin Scheduler (DRR).
Parent=
Configures the parent Queueing Discipline (qdisc). Takes
one of "root", or a qdisc identifier. The qdisc identifier is
specified as the major and minor numbers in hexadecimal in the range
0x1–Oxffff separated with a colon ("major:minor"). Defaults
to "root".
ClassId=
Configures the unique identifier of the class. It is
specified as the major and minor numbers in hexadecimal in the range
0x1–Oxffff separated with a colon ("major:minor"). Defaults
to unset.
QuantumBytes=
Specifies the amount of bytes a flow is allowed to
dequeue before the scheduler moves to the next class. When suffixed with K, M,
or G, the specified size is parsed as Kilobytes, Megabytes, or Gigabytes,
respectively, to the base of 1024. Defaults to the MTU of the interface.
The [EnhancedTransmissionSelection] section manages the queueing
discipline (qdisc) of Enhanced Transmission Selection (ETS).
Parent=
Configures the parent Queueing Discipline (qdisc). Takes
one of "root", "clsact", "ingress" or a class
identifier. The class identifier is specified as the major and minor numbers
in hexadecimal in the range 0x1–Oxffff separated with a colon
("major:minor"). Defaults to "root".
Handle=
Configures the major number of unique identifier of the
qdisc, known as the handle. Takes a hexadecimal number in the range
0x1–0xffff. Defaults to unset.
Bands=
Specifies the number of bands. An unsigned integer in the
range 1–16. This value has to be at least large enough to cover the
strict bands specified through the StrictBands= and bandwidth-sharing
bands specified in QuantumBytes=.
StrictBands=
Specifies the number of bands that should be created in
strict mode. An unsigned integer in the range 1–16.
QuantumBytes=
Specifies the white-space separated list of quantum used
in band-sharing bands. When suffixed with K, M, or G, the specified size is
parsed as Kilobytes, Megabytes, or Gigabytes, respectively, to the base of
1024. This setting can be specified multiple times. If an empty string is
assigned, then the all previous assignments are cleared.
PriorityMap=
The priority map maps the priority of a packet to a band.
The argument is a whitespace separated list of numbers. The first number
indicates which band the packets with priority 0 should be put to, the second
is for priority 1, and so on. There can be up to 16 numbers in the list. If
there are fewer, the default band that traffic with one of the unmentioned
priorities goes to is the last one. Each band number must be in the range
0..255. This setting can be specified multiple times. If an empty string is
assigned, then the all previous assignments are cleared.
The [GenericRandomEarlyDetection] section manages the queueing
discipline (qdisc) of Generic Random Early Detection (GRED).
Parent=
Configures the parent Queueing Discipline (qdisc). Takes
one of "root", "clsact", "ingress" or a class
identifier. The class identifier is specified as the major and minor numbers
in hexadecimal in the range 0x1–Oxffff separated with a colon
("major:minor"). Defaults to "root".
Handle=
Configures the major number of unique identifier of the
qdisc, known as the handle. Takes a hexadecimal number in the range
0x1–0xffff. Defaults to unset.
VirtualQueues=
Specifies the number of virtual queues. Takes a integer
in the range 1-16. Defaults to unset and kernel's default is used.
DefaultVirtualQueue=
Specifies the number of default virtual queue. This must
be less than VirtualQueue=. Defaults to unset and kernel's default is
used.
GenericRIO=
Takes a boolean. It turns on the RIO-like buffering
scheme. Defaults to unset and kernel's default is used.
The [FairQueueingControlledDelay] section manages the queueing
discipline (qdisc) of fair queuing controlled delay (FQ-CoDel).
Parent=
Configures the parent Queueing Discipline (qdisc). Takes
one of "root", "clsact", "ingress" or a class
identifier. The class identifier is specified as the major and minor numbers
in hexadecimal in the range 0x1–Oxffff separated with a colon
("major:minor"). Defaults to "root".
Handle=
Configures the major number of unique identifier of the
qdisc, known as the handle. Takes a hexadecimal number in the range
0x1–0xffff. Defaults to unset.
PacketLimit=
Specifies the hard limit on the real queue size. When
this limit is reached, incoming packets are dropped. Defaults to unset and
kernel's default is used.
MemoryLimitBytes=
Specifies the limit on the total number of bytes that can
be queued in this FQ-CoDel instance. When suffixed with K, M, or G, the
specified size is parsed as Kilobytes, Megabytes, or Gigabytes, respectively,
to the base of 1024. Defaults to unset and kernel's default is used.
Flows=
Specifies the number of flows into which the incoming
packets are classified. Defaults to unset and kernel's default is used.
TargetSec=
Takes a timespan. Specifies the acceptable minimum
standing/persistent queue delay. Defaults to unset and kernel's default is
used.
IntervalSec=
Takes a timespan. This is used to ensure that the
measured minimum delay does not become too stale. Defaults to unset and
kernel's default is used.
QuantumBytes=
Specifies the number of bytes used as the
"deficit" in the fair queuing algorithm timespan. When suffixed with
K, M, or G, the specified size is parsed as Kilobytes, Megabytes, or
Gigabytes, respectively, to the base of 1024. Defaults to unset and kernel's
default is used.
ECN=
Takes a boolean. This can be used to mark packets instead
of dropping them. Defaults to unset and kernel's default is used.
CEThresholdSec=
Takes a timespan. This sets a threshold above which all
packets are marked with ECN Congestion Experienced (CE). Defaults to unset and
kernel's default is used.
The [FairQueueing] section manages the queueing discipline (qdisc)
of fair queue traffic policing (FQ).
Parent=
Configures the parent Queueing Discipline (qdisc). Takes
one of "root", "clsact", "ingress" or a class
identifier. The class identifier is specified as the major and minor numbers
in hexadecimal in the range 0x1–Oxffff separated with a colon
("major:minor"). Defaults to "root".
Handle=
Configures the major number of unique identifier of the
qdisc, known as the handle. Takes a hexadecimal number in the range
0x1–0xffff. Defaults to unset.
PacketLimit=
Specifies the hard limit on the real queue size. When
this limit is reached, incoming packets are dropped. Defaults to unset and
kernel's default is used.
FlowLimit=
Specifies the hard limit on the maximum number of packets
queued per flow. Defaults to unset and kernel's default is used.
QuantumBytes=
Specifies the credit per dequeue RR round, i.e. the
amount of bytes a flow is allowed to dequeue at once. When suffixed with K, M,
or G, the specified size is parsed as Kilobytes, Megabytes, or Gigabytes,
respectively, to the base of 1024. Defaults to unset and kernel's default is
used.
InitialQuantumBytes=
Specifies the initial sending rate credit, i.e. the
amount of bytes a new flow is allowed to dequeue initially. When suffixed with
K, M, or G, the specified size is parsed as Kilobytes, Megabytes, or
Gigabytes, respectively, to the base of 1024. Defaults to unset and kernel's
default is used.
MaximumRate=
Specifies the maximum sending rate of a flow. When
suffixed with K, M, or G, the specified size is parsed as Kilobits, Megabits,
or Gigabits, respectively, to the base of 1000. Defaults to unset and kernel's
default is used.
Buckets=
Specifies the size of the hash table used for flow
lookups. Defaults to unset and kernel's default is used.
OrphanMask=
Takes an unsigned integer. For packets not owned by a
socket, fq is able to mask a part of hash and reduce number of buckets
associated with the traffic. Defaults to unset and kernel's default is
used.
Pacing=
Takes a boolean, and enables or disables flow pacing.
Defaults to unset and kernel's default is used.
CEThresholdSec=
Takes a timespan. This sets a threshold above which all
packets are marked with ECN Congestion Experienced (CE). Defaults to unset and
kernel's default is used.
The [TrivialLinkEqualizer] section manages the queueing discipline
(qdisc) of trivial link equalizer (teql).
Parent=
Configures the parent Queueing Discipline (qdisc). Takes
one of "root", "clsact", "ingress" or a class
identifier. The class identifier is specified as the major and minor numbers
in hexadecimal in the range 0x1–Oxffff separated with a colon
("major:minor"). Defaults to "root".
Handle=
Configures the major number of unique identifier of the
qdisc, known as the handle. Takes a hexadecimal number in the range
0x1–0xffff. Defaults to unset.
Id=
Specifies the interface ID "N" of teql.
Defaults to "0". Note that when teql is used, currently, the module
sch_teql with max_equalizers=N+1 option must be loaded before
systemd-networkd is started.
The [HierarchyTokenBucket] section manages the queueing discipline
(qdisc) of hierarchy token bucket (htb).
Parent=
Configures the parent Queueing Discipline (qdisc). Takes
one of "root", "clsact", "ingress" or a class
identifier. The class identifier is specified as the major and minor numbers
in hexadecimal in the range 0x1–Oxffff separated with a colon
("major:minor"). Defaults to "root".
Handle=
Configures the major number of unique identifier of the
qdisc, known as the handle. Takes a hexadecimal number in the range
0x1–0xffff. Defaults to unset.
DefaultClass=
Takes the minor id in hexadecimal of the default class.
Unclassified traffic gets sent to the class. Defaults to unset.
RateToQuantum=
Takes an unsigned integer. The DRR quantums are
calculated by dividing the value configured in Rate= by
RateToQuantum=.
The [HierarchyTokenBucketClass] section manages the traffic
control class of hierarchy token bucket (htb).
Parent=
Configures the parent Queueing Discipline (qdisc). Takes
one of "root", or a qdisc identifier. The qdisc identifier is
specified as the major and minor numbers in hexadecimal in the range
0x1–Oxffff separated with a colon ("major:minor"). Defaults
to "root".
ClassId=
Configures the unique identifier of the class. It is
specified as the major and minor numbers in hexadecimal in the range
0x1–Oxffff separated with a colon ("major:minor"). Defaults
to unset.
Priority=
Specifies the priority of the class. In the round-robin
process, classes with the lowest priority field are tried for packets
first.
QuantumBytes=
Specifies how many bytes to serve from leaf at once. When
suffixed with K, M, or G, the specified size is parsed as Kilobytes,
Megabytes, or Gigabytes, respectively, to the base of 1024.
MTUBytes=
Specifies the maximum packet size we create. When
suffixed with K, M, or G, the specified size is parsed as Kilobytes,
Megabytes, or Gigabytes, respectively, to the base of 1024.
OverheadBytes=
Takes an unsigned integer which specifies per-packet size
overhead used in rate computations. When suffixed with K, M, or G, the
specified size is parsed as Kilobytes, Megabytes, or Gigabytes, respectively,
to the base of 1024.
Rate=
Specifies the maximum rate this class and all its
children are guaranteed. When suffixed with K, M, or G, the specified size is
parsed as Kilobits, Megabits, or Gigabits, respectively, to the base of 1000.
This setting is mandatory.
CeilRate=
Specifies the maximum rate at which a class can send, if
its parent has bandwidth to spare. When suffixed with K, M, or G, the
specified size is parsed as Kilobits, Megabits, or Gigabits, respectively, to
the base of 1000. When unset, the value specified with Rate= is
used.
BufferBytes=
Specifies the maximum bytes burst which can be
accumulated during idle period. When suffixed with K, M, or G, the specified
size is parsed as Kilobytes, Megabytes, or Gigabytes, respectively, to the
base of 1024.
CeilBufferBytes=
Specifies the maximum bytes burst for ceil which can be
accumulated during idle period. When suffixed with K, M, or G, the specified
size is parsed as Kilobytes, Megabytes, or Gigabytes, respectively, to the
base of 1024.
The [HeavyHitterFilter] section manages the queueing discipline
(qdisc) of Heavy Hitter Filter (hhf).
Parent=
Configures the parent Queueing Discipline (qdisc). Takes
one of "root", "clsact", "ingress" or a class
identifier. The class identifier is specified as the major and minor numbers
in hexadecimal in the range 0x1–Oxffff separated with a colon
("major:minor"). Defaults to "root".
Handle=
Configures the major number of unique identifier of the
qdisc, known as the handle. Takes a hexadecimal number in the range
0x1–0xffff. Defaults to unset.
PacketLimit=
Specifies the hard limit on the queue size in number of
packets. When this limit is reached, incoming packets are dropped. An unsigned
integer in the range 0–4294967294. Defaults to unset and kernel's
default is used.
The [QuickFairQueueing] section manages the queueing discipline
(qdisc) of Quick Fair Queueing (QFQ).
Parent=
Configures the parent Queueing Discipline (qdisc). Takes
one of "root", "clsact", "ingress" or a class
identifier. The class identifier is specified as the major and minor numbers
in hexadecimal in the range 0x1–Oxffff separated with a colon
("major:minor"). Defaults to "root".
Handle=
Configures the major number of unique identifier of the
qdisc, known as the handle. Takes a hexadecimal number in the range
0x1–0xffff. Defaults to unset.
The [QuickFairQueueingClass] section manages the traffic control
class of Quick Fair Queueing (qfq).
Parent=
Configures the parent Queueing Discipline (qdisc). Takes
one of "root", or a qdisc identifier. The qdisc identifier is
specified as the major and minor numbers in hexadecimal in the range
0x1–Oxffff separated with a colon ("major:minor"). Defaults
to "root".
ClassId=
Configures the unique identifier of the class. It is
specified as the major and minor numbers in hexadecimal in the range
0x1–Oxffff separated with a colon ("major:minor"). Defaults
to unset.
Weight=
Specifies the weight of the class. Takes an integer in
the range 1..1023. Defaults to unset in which case the kernel default is
used.
MaxPacketBytes=
Specifies the maximum packet size in bytes for the class.
When suffixed with K, M, or G, the specified size is parsed as Kilobytes,
Megabytes, or Gigabytes, respectively, to the base of 1024. When unset, the
kernel default is used.
The [BridgeVLAN] section manages the VLAN ID configuration of a
bridge port and accepts the following keys. Specify several [BridgeVLAN]
sections to configure several VLAN entries. The VLANFiltering= option
has to be enabled, see the [Bridge] section in systemd.netdev(5).
VLAN=
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.
EgressUntagged=
The VLAN ID specified here will be used to untag frames
on egress. Configuring EgressUntagged= implicates the use of
VLAN= above and will enable the VLAN ID for ingress as well. This can
be either a single ID or a range M-N.
PVID=
The Port VLAN ID specified here is assigned to all
untagged frames at ingress. PVID= can be used only once. Configuring
PVID= implicates the use of VLAN= above and will enable the VLAN
ID for ingress as well.
Example 1. Static network configuration
# /etc/systemd/network/50-static.network
[Match]
Name=enp2s0
[Network]
Address=192.168.0.15/24
Gateway=192.168.0.1
This brings interface "enp2s0" up with a static address.
The specified gateway will be used for a default route.
Example 2. DHCP on ethernet links
# /etc/systemd/network/80-dhcp.network
[Match]
Name=en*
[Network]
DHCP=yes
This will enable DHCPv4 and DHCPv6 on all interfaces with names
starting with "en" (i.e. ethernet interfaces).
Example 3. IPv6 Prefix Delegation
# /etc/systemd/network/55-ipv6-pd-upstream.network
[Match]
Name=enp1s0
[Network]
DHCP=ipv6
# /etc/systemd/network/56-ipv6-pd-downstream.network
[Match]
Name=enp2s0
[Network]
IPv6SendRA=yes
DHCPv6PrefixDelegation=yes
This will enable DHCPv6-PD on the interface enp1s0 as an upstream
interface where the DHCPv6 client is running and enp2s0 as a downstream
interface where the prefix is delegated to. The delegated prefixes are
distributed by IPv6 Router Advertisement on the downstream network.
Example 4. A bridge with two enslaved
links
# /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
# /etc/systemd/network/25-bridge-slave-interface-1.network
[Match]
Name=enp2s0
[Network]
Bridge=bridge0
# /etc/systemd/network/25-bridge-slave-interface-2.network
[Match]
Name=wlp3s0
[Network]
Bridge=bridge0
This creates a bridge and attaches devices "enp2s0" and
"wlp3s0" 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.
Example 5.
# /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
This overrides the configuration specified in the previous example
for the interface "enp2s0", 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.
Example 6. Various tunnels
/etc/systemd/network/25-tunnels.network
[Match]
Name=ens1
[Network]
Tunnel=ipip-tun
Tunnel=sit-tun
Tunnel=gre-tun
Tunnel=vti-tun
/etc/systemd/network/25-tunnel-ipip.netdev
[NetDev]
Name=ipip-tun
Kind=ipip
/etc/systemd/network/25-tunnel-sit.netdev
[NetDev]
Name=sit-tun
Kind=sit
/etc/systemd/network/25-tunnel-gre.netdev
[NetDev]
Name=gre-tun
Kind=gre
/etc/systemd/network/25-tunnel-vti.netdev
[NetDev]
Name=vti-tun
Kind=vti
This will bring interface "ens1" up and create an IPIP
tunnel, a SIT tunnel, a GRE tunnel, and a VTI tunnel using it.
Example 7. A bond device
# /etc/systemd/network/30-bond1.network
[Match]
Name=bond1
[Network]
DHCP=ipv6
# /etc/systemd/network/30-bond1.netdev
[NetDev]
Name=bond1
Kind=bond
# /etc/systemd/network/30-bond1-dev1.network
[Match]
MACAddress=52:54:00:e9:64:41
[Network]
Bond=bond1
# /etc/systemd/network/30-bond1-dev2.network
[Match]
MACAddress=52:54:00:e9:64:42
[Network]
Bond=bond1
This will create a bond device "bond1" 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.
Example 8. Virtual Routing and Forwarding
(VRF)
Add the "bond1" interface to the VRF master interface
"vrf1". This will redirect routes generated on this interface to
be within the routing table defined during VRF creation. For kernels before
4.8 traffic won't be redirected towards the VRFs routing table unless
specific ip-rules are added.
# /etc/systemd/network/25-vrf.network
[Match]
Name=bond1
[Network]
VRF=vrf1
Example 9. MacVTap
This brings up a network interface "macvtap-test" and
attaches it to "enp0s25".
# /lib/systemd/network/25-macvtap.network
[Match]
Name=enp0s25
[Network]
MACVTAP=macvtap-test
Example 10. A Xfrm interface with physical
underlying device.
# /etc/systemd/network/27-xfrm.netdev
[NetDev]
Name=xfrm0
[Xfrm]
InterfaceId=7
# /etc/systemd/network/27-eth0.network
[Match]
Name=eth0
[Network]
Xfrm=xfrm0
This creates a "xfrm0" interface and binds it to the
"eth0" device. This allows hardware based ipsec offloading to the
"eth0" nic. If offloading is not needed, xfrm interfaces can be
assigned to the "lo" device.
- 1.
- RFC 7217
https://tools.ietf.org/html/rfc7217
- 2.
- Link-Local Multicast Name Resolution
https://tools.ietf.org/html/rfc4795
- 3.
- Multicast DNS
https://tools.ietf.org/html/rfc6762
- 4.
- DNS-over-TLS
https://tools.ietf.org/html/rfc7858
- 5.
- DNSSEC
https://tools.ietf.org/html/rfc4033
- 6.
- IEEE 802.1AB-2016
https://standards.ieee.org/findstds/standard/802.1AB-2016.html
- 7.
- ip-sysctl.txt
https://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt
- 8.
- RFC 4941
https://tools.ietf.org/html/rfc4941
- 9.
- RFC 1027
https://tools.ietf.org/html/rfc1027
- 10.
- RFC 6275
https://tools.ietf.org/html/rfc6275
- 11.
- RFC 5224
https://tools.ietf.org/html/rfc5227
- 12.
- RFC 4862
https://tools.ietf.org/html/rfc4862
- 13.
- RFC 3041
https://tools.ietf.org/html/rfc3041
- 14.
- RFC 3484
https://tools.ietf.org/html/rfc3484
- 15.
- RFC 4191
https://tools.ietf.org/html/rfc4191
- 16.
- RFC 7844
https://tools.ietf.org/html/rfc7844
- 17.
- RFC 8520
https://tools.ietf.org/html/rfc8520
- 18.
- C-style escapes
https://en.wikipedia.org/wiki/Escape_sequences_in_C#Table_of_escape_sequences
- 19.
- RFC 3315
https://tools.ietf.org/html/rfc3315#section-17.2.1
- 20.
- RFC 7084
https://tools.ietf.org/html/rfc7084
- 21.
- RFC 4291
https://tools.ietf.org/html/rfc4291#section-2.5.4
- 22.
- RFC 4861
https://tools.ietf.org/html/rfc4861