systemd.network(5)
NAME
systemd.network - Network configuration
SYNOPSIS
network.network
DESCRIPTION
Network setup is performed by systemd-networkd(8). 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 directory /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 in /lib. 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 netdev file wherever located. (Of course, since /run is temporary and /usr/lib is for vendors, it is unlikely drop-ins should be used in either of those places.) 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.
[MATCH] SECTION OPTIONS
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 device if each of the entries in the
"[Match]" section matches, or if the section is empty. The following
keys are accepted:
MACAddress=
The hardware address of the interface (use full colon-delimited
hexadecimal, e.g., 01:23:45:67:89:ab).
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 "DRIVER" of its parent device, or if that is not set the
driver as exposed by "ethtool -i" of the device itself.
Type=
A whitespace-separated list of shell-style globs matching the
device type, as exposed by the udev property "DEVTYPE".
Name=
A whitespace-separated list of shell-style globs matching the
device name, as exposed by the udev property "INTERFACE".
Host=
Matches against the hostname or machine ID of the host. See
"ConditionHost=" in systemd.unit(5) for details.
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.
KernelCommandLine=
Checks whether a specific kernel command line option is set (or if
prefixed with the exclamation mark unset). See
"ConditionKernelCommandLine=" in systemd.unit(5) for details.
Architecture=
Checks whether the system is running on a specific architecture.
See "ConditionArchitecture=" in systemd.unit(5) for details.
[LINK] SECTION OPTIONS
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=
A boolean. Enables or disables the ARP (low-level Address
Resolution Protocol) for this interface. Defaults to unset, which
means that the kernel default will be used.
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.
[NETWORK] SECTION OPTIONS
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".
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 "[DHCP]" section below for further configuration options
for the DHCP client support.
DHCPServer=
A boolean. Enables DHCPv4 server support. 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", or "ipv6". Defaults to "ipv6".
IPv4LLRoute=
A boolean. When true, sets up the route needed for non-IPv4LL hosts
to communicate with IPv4LL-only hosts. Defaults to false.
IPv6Token=
An IPv6 address with the top 64 bits unset. When set, indicates the
64-bit interface part of SLAAC IPv6 addresses for this link. Note
that the token is only ever used for SLAAC, and not for DHCPv6
addresses, even in the case DHCP is requested by router
advertisement. By default, the token is autogenerated.
LLMNR=
A boolean or "resolve". When true, enables Link-Local Multicast
Name Resolution[1] 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=
A boolean or "resolve". When true, enables Multicast DNS[2] 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).
DNSSEC=
A boolean or "allow-downgrade". When true, enables DNSSEC[3] DNS
validation support on the link. When set to "allow-downgrade",
compatibility with non-DNSSEC capable networks is increased, by
automatically turning off DNSEC 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 host name, 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-2009[4]. 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. The allocated
range is checked against all current network interfaces and all
known network configuration files to avoid address range conflicts.
The default system-wide pool consists of 192.168.0.0/16,
172.16.0.0/12 and 10.0.0.0/8 for IPv4, and fc00::/7 for IPv6. This
functionality is useful to manage a large number of dynamically
created network interfaces with the same network configuration and
automatic address range assignment.
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. This
setting is read by systemd-resolved.service(8).
Domains=
A list of domains which should be resolved using the DNS servers on
this link. Each item in the list should be a domain name,
optionally prefixed with a tilde ("~"). The domains with the prefix
are called "routing-only domains". The domains without the prefix
are called "search domains" and are first used as search suffixes
for extending single-label host names (host names containing no
dots) to become fully qualified domain names (FQDNs). If a
single-label host name is resolved on this interface, each of the
specified search domains are appended to it in turn, converting it
into a fully qualified domain name, until one of them may be
successfully resolved.
Both "search" and "routing-only" domains are used for routing of
DNS queries: look-ups for host names ending in those domains (hence
also single label names, if any "search domains" are listed), are
routed to the DNS servers configured for this interface. The domain
routing logic is particularly useful on multi-homed hosts with DNS
servers serving particular private DNS zones on each interface.
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.
NTP=
An NTP server address. 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 either a
boolean argument, 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[5] 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[6], 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=
Enable or disable IPv6 Router Advertisement (RA) reception support
for the interface. Takes a boolean parameter. If true, RAs are
accepted; if false, RAs are ignored, independently of the local
forwarding state. When not set, the kernel default is used, and RAs
are accepted only when local forwarding is disabled for that
interface. When RAs are accepted, they may trigger the start of the
DHCPv6 client if the relevant flags are set in the RA data, or if
no routers are found on the link.
Further settings for the IPv6 RA support may be configured in the
"[IPv6AcceptRA]" section, see below.
Also see ip-sysctl.txt[5] 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.
IPv6DuplicateAddressDetection=
Configures the amount of IPv6 Duplicate Address Detection (DAD)
probes to send. Defaults to unset.
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. Defaults to unset.
ProxyARP=
A boolean. Configures proxy ARP. 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[7]. Defaults to unset.
Bridge=
The name of the bridge to add the link to.
Bond=
The name of the bond to add the link to.
VRF=
The name of the VRF to add the link to.
VLAN=
The name of a VLAN to create on the link. This option may be
specified more than once.
MACVLAN=
The name of a MACVLAN to create on the link. This option may be
specified more than once.
VXLAN=
The name of a VXLAN to create on the link. This option may be
specified more than once.
Tunnel=
The name of a Tunnel to create on the link. This option may be
specified more than once.
[ADDRESS] SECTION OPTIONS
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.
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.
HomeAddress=
Takes a boolean argument. Designates this address the "home
address" as defined in RFC 6275[8]. Supported only on IPv6.
Defaults to false.
DuplicateAddressDetection=
Takes a boolean argument. Do not perform Duplicate Address
Detection RFC 4862[9] when adding this address. Supported only on
IPv6. Defaults to false.
ManageTemporaryAddress=
Takes a boolean argument. If true the kernel manage temporary
addresses created from this one as template on behalf of Privacy
Extensions RFC 3041[10]. For this to become active, the
use_tempaddr sysctl setting has to be set to a value greater than
zero. The given address needs to have a prefix length of 64. This
flag allows to use privacy extensions in a manually configured
network, just like if stateless auto-configuration was active.
Defaults to false.
PrefixRoute=
Takes a boolean argument. When adding or modifying an IPv6 address,
the userspace application needs a way to suppress adding a prefix
route. This is for example relevant together with
IFA_F_MANAGERTEMPADDR, where userspace creates autoconf generated
addresses, but depending on on-link, no route for the prefix should
be added. Defaults to false.
AutoJoin=
Takes a boolean argument. 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".
[ROUTE] SECTION OPTIONS
The "[Route]" section accepts the following keys. Specify several
"[Route]" sections to configure several routes.
Gateway=
As in the "[Network]" section.
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).
Scope=
The scope of the route, which can be "global", "link" or "host".
Defaults to "global".
PreferredSource=
The preferred source address of the route. The address must be in
the format described in inet_pton(3).
Table=num
The table identifier for the route (a number between 1 and
4294967295, or 0 to unset). The table can be retrieved using ip
route show table num.
[DHCP] SECTION OPTIONS
The "[DHCP]" section configures the DHCPv4 and DHCP6 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).
UseNTP=
When true (the default), the NTP servers received from the DHCP
server will be used by systemd-timesyncd and take precedence over
any statically configured ones.
UseMTU=
When true, the interface maximum transmission unit from the DHCP
server will be used on the current link. Defaults to false.
SendHostname=
When true (the default), the machine's hostname will be sent to the
DHCP server.
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.
UseDomains=
Takes a boolean argument, 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 host names, in particular
of single-label names. It is generally safer to use the supplied
domain only as routing domain, rather than as search domain, in
order to not have it affect local resolution of single-label names.
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.
UseTimezone=
When true, the timezone received from the DHCP server will be set
as timezone of the local system. Defaults to "no".
CriticalConnection=
When true, the connection will never be torn down even if the DHCP
lease expires. This is contrary to the DHCP specification, but may
be the best choice if, say, the root filesystem relies on this
connection. Defaults to false.
ClientIdentifier=
The DHCPv4 client identifier to use. Either "mac" to use the MAC
address of the link or "duid" (the default, see below) to use an
RFC4361-compliant Client ID.
VendorClassIdentifier=
The vendor class identifier used to identify vendor type and
configuration.
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.
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.
[IPV6ACCEPTRA] SECTION OPTIONS
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 argument, 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 host names, in particular
of single-label names. It is generally safer to use the supplied
domain only as routing domain, rather than as search domain, in
order to not have it affect local resolution of single-label names.
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.
[DHCPSERVER] SECTION OPTIONS
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=
Configures whether the DHCP leases handed out to clients shall
contain DNS server information. The EmitDNS= setting takes a
boolean argument and 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 or NTP server information at a later
point. DNS server propagation does not take /etc/resolv.conf into
account. Also, note that the leases are not refreshed if the uplink
network configuration changes. To ensure clients regularly acquire
the most current uplink DNS server information, it is thus
advisable to shorten the DHCP lease time via MaxLeaseTimeSec=
described above.
EmitNTP=, NTP=
Similar to the EmitDNS= and DNS= settings described above, these
settings configure whether and what NTP server information shall be
emitted as part of the DHCP lease. The same syntax, propagation
semantics and defaults apply as for 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=
Configures whether the DHCP leases handed out to clients shall
contain timezone information. The EmitTimezone= setting takes a
boolean argument and 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.
[BRIDGE] SECTION OPTIONS
The "[Bridge]" section accepts the following keys.
UnicastFlood=
A boolean. Controls whether the bridge should flood traffic for
which an FDB entry is missing and the destination is unknown
through this port. Defaults to on.
HairPin=
A boolean. Configures whether traffic may be sent back out of the
port on which it was received. By default, this flag is false, and
the bridge will not forward traffic back out of the receiving port.
UseBPDU=
A boolean. Configures whether STP Bridge Protocol Data Units will
be processed by the bridge port. Defaults to yes.
FastLeave=
A boolean. This flag allows the bridge to immediately stop
multicast traffic on a port that receives an IGMP Leave message. It
is only used with IGMP snooping if enabled on the bridge. Defaults
to off.
AllowPortToBeRoot=
A boolean. Configures whether a given port is allowed to become a
root port. Only used when STP is enabled on the bridge. Defaults to
on.
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.
[BRIDGEFDB] SECTION OPTIONS
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.
VLANId=
The VLAN ID for the new static MAC table entry. If omitted, no VLAN
ID info is appended to the new static MAC table entry.
[BRIDGEVLAN] SECTION OPTIONS
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 "[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
Example 1. /etc/systemd/network/50-static.network
[Match]
Name=enp2s0
[Network]
Address=192.168.0.15/24
Gateway=192.168.0.1
Example 2. /etc/systemd/network/80-dhcp.network
[Match]
Name=en*
[Network]
DHCP=yes
Example 3. /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
Example 4. /etc/systemd/network/25-bridge-slave-interface.network
[Match]
Name=enp2s0
[Network]
Bridge=bridge0
Example 5. /etc/systemd/network/25-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
Example 6. /etc/systemd/network/25-ipip.network
[Match]
Name=em1
[Network]
Tunnel=ipip-tun
Example 7. /etc/systemd/network/25-sit.network
[Match]
Name=em1
[Network]
Tunnel=sit-tun
Example 8. /etc/systemd/network/25-gre.network
[Match]
Name=em1
[Network]
Tunnel=gre-tun
Example 9. /etc/systemd/network/25-vti.network
[Match]
Name=em1
[Network]
Tunnel=vti-tun
Example 10. /etc/systemd/network/25-bond.network
[Match]
Name=bond1
[Network]
DHCP=yes
Example 11. /etc/systemd/network/25-vrf.network
Add the bond1 interface to the VRF master interface vrf-test. This will
redirect routes generated on this interface to be within the routing
table defined during VRF creation. Traffic won't be redirected towards
the VRFs routing table unless specific ip-rules are added.
[Match]
Name=bond1
[Network]
VRF=vrf-test
SEE ALSO
systemd(1), systemd-networkd.service(8), systemd.link(5), systemd.netdev(5), systemd-resolved.service(8)
NOTES
1. Link-Local Multicast Name Resolution
https://tools.ietf.org/html/rfc4795
2. Multicast DNS
https://tools.ietf.org/html/rfc6762
3. DNSSEC
https://tools.ietf.org/html/rfc4033
4. IEEE 802.1AB-2009
http://standards.ieee.org/getieee802/download/802.1AB-2009.pdf
5. ip-sysctl.txt
https://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt
6. RFC 4941
https://tools.ietf.org/html/rfc4941
7. RFC 1027
https://tools.ietf.org/html/rfc1027
8. RFC 6275
https://tools.ietf.org/html/rfc6275
9. RFC 4862
https://tools.ietf.org/html/rfc4862
10. RFC 3041
https://tools.ietf.org/html/rfc3041
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